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Sample records for affect plant reproduction

  1. Ozone affects gas exchange, growth and reproductive development in Brassica campestris (Wisconsin fast plants).

    PubMed

    Black, V J; Stewart, C A; Roberts, J A; Black, C R

    2007-01-01

    Exposure to ozone (O(3)) may affect vegetative and reproductive development, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the impact on reproductive development of exposing Brassica campestris (Wisconsin Fast Plants) to ozone during vegetative growth. Plants were exposed to 70 ppb ozone for 2 d during late vegetative growth or 10 d spanning most of the vegetative phase. Effects on gas exchange, vegetative growth, reproductive development and seed yield were determined. Impacts on gas exchange and foliar injury were related to pre-exposure stomatal conductance. Exposure for 2 d had no effect on growth or reproductive characteristics, whereas 10-d exposure reduced vegetative growth and reproductive site number on the terminal raceme. Mature seed number and weight per pod and per plant were unaffected because seed abortion was reduced. The observation that mature seed yield per plant was unaffected by exposure during the vegetative phase, despite adverse effects on physiological, vegetative and reproductive processes, shows that indeterminate species such as B. campestris possess sufficient compensatory flexibility to avoid reductions in seed production. PMID:17803646

  2. Teaching Plant Reproduction.

    ERIC Educational Resources Information Center

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  3. CO2, Temperature, and Soil Moisture Interactions Affect NDVI and Reproductive Phenology in Old-Field Plant Communities

    NASA Astrophysics Data System (ADS)

    Engel, C.; Weltzin, J.; Norby, R.

    2004-12-01

    Plant community composition and ecosystem function may be altered by global atmospheric and climate change, including increased atmospheric [CO2], temperature, and varying precipitation regimes. We are conducting an experiment at Oak Ridge National Laboratory (ORNL) utilizing open-top chambers to administer experimental treatments of elevated CO2 (+300 ppm), warming (+ 3 degrees Celsius), and varying soil moisture availability to experimental plant communities constructed of seven common old-field species, including C3 and C4 grasses, forbs, and legumes. During 2004 we monitored plant community phenology (NDVI) and plant reproductive phenology. Early in the year, NDVI was greater in wet treatment plots, and was unaffected by main effects of temperature or CO2. This result suggests that early in the season warming is insufficient to affect early canopy development. Differences in soil moisture sustained throughout the winter and into early spring may constitute an important control on early canopy greenup. Elevated CO2 alleviated detrimental effects of warming on NDVI, but only early in the season. As ambient temperatures increased, elevated temperatures negatively impacted NDVI only in the dry plots. Wetter conditions ameliorate the effects of warming on canopy greenness during the warmer seasons of the year. Warming increased rates of bolting, number of inflorescences, and time to reproductive maturity for Andropogon virginicus (a C4 bunchgrass). Solidago Canadensis (a C3 late-season forb) also produced flowers earlier in elevated temperatures. Conversely, none of the C3 grasses and forbs that bolt or flower in late spring or early summer responded to temperature or CO2. Results indicate that warming and drought may impact plant community phenology, and plant species reproductive phenology. Clearly community phenology is driven by complex interactions among temperature, water, and CO2 that change throughout the season. Our data stresses the importance of

  4. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae)

    PubMed Central

    Narbona, Eduardo; Dirzo, Rodolfo

    2010-01-01

    Background and Aims Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Methods Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Key Results Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. Conclusions The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress. PMID:20519239

  5. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future. PMID:25537120

  6. Plant reproduction in spaceflight environments

    NASA Technical Reports Server (NTRS)

    Musgrave, M. E.; Kuang, A.; Porterfield, D. M.

    1997-01-01

    Because plant reproduction is a complex developmental process there are many possible sites of perturbation by the unusual environments of orbital spacecraft. Previous long-duration experiments on Soviet platforms shared features of slowed development through the vegetative stage of plant growth and aborted reproductive function. Our goal has been to understand how special features of the spaceflight environment impact physiological function and reproductive development. In a series of short-duration experiments in the Shuttle mid-deck we studied early reproductive development in Arabidopsis thaliana. Pollen and ovule development aborted at an early stage in the first experiment on STS-54 which utilized closed plant growth chambers. Post-flight analysis suggested that the plants may have been carbon dioxide limited. Subsequent experiments utilized carbon dioxide enrichment (on STS-51) and cabin air flow-through with an air exchange system (on STS-68). Both modifications allowed pollen and ovule development to occur normally on orbit, and full reproductive development up to the stage of an immature seed occurred on STS-68. However, analysis of plant roots from these experiments demonstrated a limitation in rootzone aeration in the spaceflight material that was not mitigated by these procedures. In the future, additional resources (crew time, upgraded flight hardware, and special platforms) will invite more elaborate, long-duration experimentation. On the ISS, a variable speed centrifuge and upgraded plant habitats will permit detailed experiments on the role of gravity in shaping the plant micro-environment, and what influence this plays during reproduction.

  7. Influences of clonality on plant sexual reproduction

    PubMed Central

    Barrett, Spencer C. H.

    2015-01-01

    Flowering plants possess an unrivaled diversity of mechanisms for achieving sexual and asexual reproduction, often simultaneously. The commonest type of asexual reproduction is clonal growth (vegetative propagation) in which parental genotypes (genets) produce vegetative modules (ramets) that are capable of independent growth, reproduction, and often dispersal. Clonal growth leads to an expansion in the size of genets and increased fitness because large floral displays increase fertility and opportunities for outcrossing. Moreover, the clonal dispersal of vegetative propagules can assist “mate finding,” particularly in aquatic plants. However, there are ecological circumstances in which functional antagonism between sexual and asexual reproductive modes can negatively affect the fitness of clonal plants. Populations of heterostylous and dioecious species have a small number of mating groups (two or three), which should occur at equal frequency in equilibrium populations. Extensive clonal growth and vegetative dispersal can disrupt the functioning of these sexual polymorphisms, resulting in biased morph ratios and populations with a single mating group, with consequences for fertility and mating. In populations in which clonal propagation predominates, mutations reducing fertility may lead to sexual dysfunction and even the loss of sex. Recent evidence suggests that somatic mutations can play a significant role in influencing fitness in clonal plants and may also help explain the occurrence of genetic diversity in sterile clonal populations. Highly polymorphic genetic markers offer outstanding opportunities for gaining novel insights into functional interactions between sexual and clonal reproduction in flowering plants. PMID:26195747

  8. Asexual Plant Reproduction. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    These lesson plans are intended for use in conducting classes on asexual plant reproduction. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about asexual plant reproduction/propagation. The following topics are among those discussed: plant reproduction methods,…

  9. Sexual Plant Reproduction. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    These lesson plans are intended for use in conducting classes on sexual plant reproduction. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about sexual plant reproduction/propagation. The following topics are among those discussed: sexual and asexual plant…

  10. Leptin: a possible metabolic signal affecting reproduction.

    PubMed

    Spicer, L J

    2001-11-01

    Since its discovery in 1994, leptin, a protein hormone synthesized and secreted by adipose tissue, has been shown to regulate feed intake in several species including sheep and pigs. Although a nimiety of information exists regarding the physiological role of leptin in rodents and humans, the regulation and action of leptin in domestic animals is less certain. Emerging evidence in several species indicates that leptin may also affect the hypothalamo-pituitary-gonadal axis. Leptin receptor mRNA is present in the anterior pituitary and hypothalamus of several species, including sheep. In rats, effects of leptin on GnRH, LH and FSH secretion have been inconsistent, with leptin exhibiting both stimulatory and inhibitory action in vivo and in vitro. Evidence to support direct action of leptin at the level of the gonad indicates that the leptin receptor and its mRNA are present in ovarian tissue of several species, including cattle. These leptin receptors are functional, since leptin inhibits insulin-induced steroidogenesis of both granulosa and thecal cells of cattle in vitro. Leptin receptor mRNA is also found in the testes of rodents. As with the ovary, these receptors are functional, at least in rats, since leptin inhibits hCG-induced testosterone secretion by Leydig cells in vitro. During pregnancy, placental production of leptin may be a major contributor to the increase in maternal leptin in primates but not rodents. However, in both primates and rodents, leptin receptors exist in placental tissues and may regulate metabolism of the fetal-placental unit. As specific leptin immunoassays are developed for domestic animals, in vivo associations may then be made among leptin, body energy stores, dietary energy intake and reproductive function. This may lead to a more definitive role of leptin in domestic animal reproduction. PMID:11872320

  11. Epigenetic reprogramming in plant sexual reproduction.

    PubMed

    Kawashima, Tomokazu; Berger, Frédéric

    2014-09-01

    Epigenetic reprogramming consists of global changes in DNA methylation and histone modifications. In mammals, epigenetic reprogramming is primarily associated with sexual reproduction and occurs during both gametogenesis and early embryonic development. Such reprogramming is crucial not only to maintain genomic integrity through silencing transposable elements but also to reset the silenced status of imprinted genes. In plants, observations of stable transgenerational inheritance of epialleles have argued against reprogramming. However, emerging evidence supports that epigenetic reprogramming indeed occurs during sexual reproduction in plants and that it has a major role in maintaining genome integrity and a potential contribution to epiallelic variation. PMID:25048170

  12. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success. PMID:18410290

  13. Enhancement of reproductive heat tolerance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current study investigated the enhancement of plant reproductive heat tolerance through the use of a gene encoding the Arabidopsis thaliana heat shock protein 101 (AtHSP101) not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The Arabidopsis thali...

  14. Reproductive systems and evolution in vascular plants

    PubMed Central

    Holsinger, Kent E.

    2000-01-01

    Differences in the frequency with which offspring are produced asexually, through self-fertilization and through sexual outcrossing, are a predominant influence on the genetic structure of plant populations. Selfers and asexuals have fewer genotypes within populations than outcrossers with similar allele frequencies, and more genetic diversity in selfers and asexuals is a result of differences among populations than in sexual outcrossers. As a result of reduced levels of diversity, selfers and asexuals may be less able to respond adaptively to changing environments, and because genotypes are not mixed across family lineages, their populations may accumulate deleterious mutations more rapidly. Such differences suggest that selfing and asexual lineages may be evolutionarily short-lived and could explain why they often seem to be of recent origin. Nonetheless, the origin and maintenance of different reproductive modes must be linked to individual-level properties of survival and reproduction. Sexual outcrossers suffer from a cost of outcrossing that arises because they do not contribute to selfed or asexual progeny, whereas selfers and asexuals may contribute to outcrossed progeny. Selfing and asexual reproduction also may allow reproduction when circumstances reduce opportunities for a union of gametes produced by different individuals, a phenomenon known as reproductive assurance. Both the cost of outcrossing and reproductive assurance lead to an over-representation of selfers and asexuals in newly formed progeny, and unless sexual outcrossers are more likely to survive and reproduce, they eventually will be displaced from populations in which a selfing or asexual variant arises. PMID:10860968

  15. Antiherbivore defenses alter natural selection on plant reproductive traits.

    PubMed

    Thompson, Ken A; Johnson, Marc T J

    2016-04-01

    While many studies demonstrate that herbivores alter selection on plant reproductive traits, little is known about whether antiherbivore defenses affect selection on these traits. We hypothesized that antiherbivore defenses could alter selection on reproductive traits by altering trait expression through allocation trade-offs, or by altering interactions with mutualists and/or antagonists. To test our hypothesis, we used white clover, Trifolium repens, which has a Mendelian polymorphism for the production of hydrogen cyanide-a potent antiherbivore defense. We conducted a common garden experiment with 185 clonal families of T. repens that included cyanogenic and acyanogenic genotypes. We quantified resistance to herbivores, and selection on six floral traits and phenology via male and female fitness. Cyanogenesis reduced herbivory but did not alter the expression of reproductive traits through allocation trade-offs. However, the presence of cyanogenic defenses altered natural selection on petal morphology and the number of flowers within inflorescences via female fitness. Herbivory influenced selection on flowers and phenology via female fitness independently of cyanogenesis. Our results demonstrate that both herbivory and antiherbivore defenses alter natural selection on plant reproductive traits. We discuss the significance of these results for understanding how antiherbivore defenses interact with herbivores and pollinators to shape floral evolution. PMID:26940904

  16. Social context and reproductive potential affect worker reproductive decisions in a eusocial insect.

    PubMed

    Yagound, Boris; Blacher, Pierre; Chameron, Stéphane; Châline, Nicolas

    2012-01-01

    Context-dependent decision-making conditions individual plasticity and is an integrant part of alternative reproductive strategies. In eusocial Hymenoptera (ants, bees and wasps), the discovery of worker reproductive parasitism recently challenged the view of workers as a homogeneous collective entity and stressed the need to consider them as autonomous units capable of elaborate choices which influence their fitness returns. The reproductive decisions of individual workers thus need to be investigated and taken into account to understand the regulation of reproduction in insect societies. However, we know virtually nothing about the proximate mechanisms at the basis of worker reproductive decisions. Here, we test the hypothesis that the capacity of workers to reproduce in foreign colonies lies in their ability to react differently according to the colonial context and whether this reaction is influenced by a particular internal state. Using the bumble bee Bombus terrestris, we show that workers exhibit an extremely high reproductive plasticity which is conditioned by the social context they experience. Fertile workers reintroduced into their mother colony reverted to sterility, as expected. On the contrary, a high level of ovary activity persisted in fertile workers introduced into a foreign nest, and this despite more frequent direct contacts with the queen and the brood than control workers. Foreign workers' reproductive decisions were not affected by the resident queen, their level of fertility being similar whether or not the queen was removed from the host colony. Workers' physiological state at the time of introduction is also of crucial importance, since infertile workers failed to develop a reproductive phenotype in a foreign nest. Therefore, both internal and environmental factors appear to condition individual reproductive strategies in this species, suggesting that more complex decision-making mechanisms are involved in the regulation of worker

  17. Clonal Patch Size and Ramet Position of Leymus chinensis Affected Reproductive Allocation

    PubMed Central

    Zhang, Zhuo; Yang, Yunfei

    2015-01-01

    Reproductive allocation is critically important for population maintenance and usually varies with not only environmental factors but also biotic ones. As a typical rhizome clonal plant in China's northern grasslands, Leymus chinensis usually dominates the steppe communities and grows in clonal patches. In order to clarify the sexual reproductive allocation of L. chinensis in the process of the growth and expansion, we selected L. chinensis clonal patches of a range of sizes to examine the reproductive allocation and allometric growth of the plants. Moreover, the effects of position of L. chinensis ramets within the patch on their reproductive allocation were also examined. Clonal patch size and position both significantly affected spike biomass, reproductive tiller biomass and SPIKE/TILLER biomass ratio. From the central to the marginal zone, both the spike biomass and reproductive tiller biomass displayed an increasing trend in all the five patch size categories except for reproductive tiller biomass in 15–40m2 category. L. chinensis had significantly larger SPIKE/TILLER biomass ratio in marginal zone than in central zone of clonal patches that are larger than 15 m2 in area. Regression analysis showed that the spike biomass and SPIKE/TILLER biomass ratio were negatively correlated with clonal patch size while patch size showed significantly positive effect on SEED/SPIKE biomass ratio, but the reproductive tiller biomass and SEED/TILLER biomass ratio were not dependent on clonal patch size. The relationships between biomass of spike and reproductive tiller, between mature seed biomass and spike biomass and between mature seed biomass and reproductive tiller biomass were significant allometric for all or some of patch size categories, respectively. The slopes of all these allometric relationships were significantly different from 1. The allometric growth of L. chinensis is patch size-dependent. This finding will be helpful for developing appropriate practices for

  18. Phenological change in a spring ephemeral: implications for pollination and plant reproduction.

    PubMed

    Gezon, Zachariah J; Inouye, David W; Irwin, Rebecca E

    2016-05-01

    Climate change has had numerous ecological effects, including species range shifts and altered phenology. Altering flowering phenology often affects plant reproduction, but the mechanisms behind these changes are not well-understood. To investigate why altering flowering phenology affects plant reproduction, we manipulated flowering phenology of the spring herb Claytonia lanceolata (Portulacaceae) using two methods: in 2011-2013 by altering snow pack (snow-removal vs. control treatments), and in 2013 by inducing flowering in a greenhouse before placing plants in experimental outdoor arrays (early, control, and late treatments). We measured flowering phenology, pollinator visitation, plant reproduction (fruit and seed set), and pollen limitation. Flowering occurred approx. 10 days earlier in snow-removal than control plots during all years of snow manipulation. Pollinator visitation patterns and strength of pollen limitation varied with snow treatments, and among years. Plants in the snow removal treatment were more likely to experience frost damage, and frost-damaged plants suffered low reproduction despite lack of pollen limitation. Plants in the snow removal treatment that escaped frost damage had higher pollinator visitation rates and reproduction than controls. The results of the array experiment supported the results of the snow manipulations. Plants in the early and late treatments suffered very low reproduction due either to severe frost damage (early treatment) or low pollinator visitation (late treatment) relative to control plants. Thus, plants face tradeoffs with advanced flowering time. While early-flowering plants can reap the benefits of enhanced pollination services, they do so at the cost of increased susceptibility to frost damage that can overwhelm any benefit of flowering early. In contrast, delayed flowering results in dramatic reductions in plant reproduction through reduced pollination. Our results suggest that climate change may constrain the

  19. The synthetic progestin megestrol acetate adversely affects zebrafish reproduction.

    PubMed

    Han, Jian; Wang, Qiangwei; Wang, Xianfeng; Li, Yonggang; Wen, Sheng; Liu, Shan; Ying, Guangguo; Guo, Yongyong; Zhou, Bingsheng

    2014-05-01

    Synthetic progestins contaminate the aquatic ecosystem, and may cause adverse health effects on aquatic organisms. Megestrol acetate (MTA) is present in the aquatic environment, but its possible effects on fish reproduction are unknown. In the present study, we investigated the endocrine disruption and impact of MTA on fish reproduction. After a pre-exposure period of 14 days, reproductively mature zebrafish (Danio rerio) (F0) were exposed to MTA at environmental concentrations (33, 100, 333, and 666 ng/L) for 21 days. Egg production was decreased in F0 fish exposed to MTA, with a significant decrease at 666 ng/L. The exposure significantly decreased the circulating concentrations of estradiol (E2) and testosterone (T) in female fish or 11-keto testosterone (11-KT) in male fish. MTA exposure significantly downregulated the transcription of certain genes along the hypothalamic-pituitary-gonadal (HPG) axis. MTA did not affect early embryonic development or hatching success in the F1 generation. The present study showed that MTA is a potent endocrine disruptor in fish, and short-term exposure to MTA could significantly affect reproduction in fish and negatively impact the fish population. PMID:24647012

  20. Reproductive interference between Rana dalmatina and Rana temporaria affects reproductive success in natural populations.

    PubMed

    Hettyey, Attila; Vági, Balázs; Kovács, Tibor; Ujszegi, János; Katona, Patrik; Szederkényi, Márk; Pearman, Peter B; Griggio, Matteo; Hoi, Herbert

    2014-10-01

    Experimental evidence suggests that reproductive interference between heterospecifics can seriously affect individual fitness; support from field studies for such an effect has, however, remained scarce. We studied reproductive interference in 25 natural breeding ponds in an area where two ranid frogs, Rana dalmatina and Rana temporaria, co-occur. The breeding seasons of the two species usually overlap and males of both species are often found in amplexus with heterospecific females, even though matings between heterospecifics produce no viable offspring. We estimated species abundance ratios based on the number of clutches laid and evaluated fertilization success. In ponds with low spatial complexity and a species abundance ratio biased towards R. temporaria, the average fertilization success of R. dalmatina eggs decreased, while this relationship was not detectable in spatially more complex ponds. Fertilization success of R. temporaria did not decrease with increasing relative numbers of heterospecifics. This asymmetry in fitness effects of reproductive interference may be attributed to R. temporaria males being more competitive in scramble competition for females than R. dalmatina males. Our study is among the first to demonstrate that in natural breeding populations of vertebrates interference among heterospecifics has the potential to substantially lower reproductive success at the population level, which may in turn affect population dynamics. PMID:25138258

  1. Enhancement of reproductive heat tolerance in plants.

    PubMed

    Burke, John J; Chen, Junping

    2015-01-01

    Comparison of average crop yields with reported record yields has shown that major crops exhibit annual average yields three- to seven-fold lower than record yields because of unfavorable environments. The current study investigated the enhancement of pollen heat tolerance through expressing an Arabidopsis thaliana heat shock protein 101 (AtHSP101) that is not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The AtHSP101 construct under the control of the constitutive ocs/mas 'superpromoter' was transformed into cotton Coker 312 and tobacco SRI lines via Agrobacterium mediated transformation. Thermotolerance of pollen was evaluated by in vitro pollen germination studies. Comparing with those of wild type and transgenic null lines, pollen from AtHSP101 transgenic tobacco and cotton lines exhibited significantly higher germination rate and much greater pollen tube elongation under elevated temperatures or after a heat exposure. In addition, significant increases in boll set and seed numbers were also observed in transgenic cotton lines exposed to elevated day and night temperatures in both greenhouse and field studies. The results of this study suggest that enhancing heat tolerance of reproductive tissues in plant holds promise in the development of crops with improved yield production and yield sustainability in unfavorable environments. PMID:25849955

  2. Enhancement of Reproductive Heat Tolerance in Plants

    PubMed Central

    Burke, John J.; Chen, Junping

    2015-01-01

    Comparison of average crop yields with reported record yields has shown that major crops exhibit annual average yields three- to seven-fold lower than record yields because of unfavorable environments. The current study investigated the enhancement of pollen heat tolerance through expressing an Arabidopsis thaliana heat shock protein 101 (AtHSP101) that is not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The AtHSP101 construct under the control of the constitutive ocs/mas ‘superpromoter’ was transformed into cotton Coker 312 and tobacco SRI lines via Agrobacterium mediated transformation. Thermotolerance of pollen was evaluated by in vitro pollen germination studies. Comparing with those of wild type and transgenic null lines, pollen from AtHSP101 transgenic tobacco and cotton lines exhibited significantly higher germination rate and much greater pollen tube elongation under elevated temperatures or after a heat exposure. In addition, significant increases in boll set and seed numbers were also observed in transgenic cotton lines exposed to elevated day and night temperatures in both greenhouse and field studies. The results of this study suggest that enhancing heat tolerance of reproductive tissues in plant holds promise in the development of crops with improved yield production and yield sustainability in unfavorable environments. PMID:25849955

  3. Effects of lighting and air movement on temperatures in reproductive organs of plants in a closed plant growth facility

    NASA Astrophysics Data System (ADS)

    Kitaya, Y.; Hirai, H.

    Temperature increases in plant reproductive organs such as anthers and stigmas could cause fertility impediments and thus produce sterile seeds under artificial lighting conditions without adequately controlled environments in closed plant growth facilities. There is a possibility such a situation could occur in Bioregenerative Life Support Systems under microgravity conditions in space because there will be little natural convective or thermal mixing. This study was conducted to determine the temperature of the plant reproductive organs as affected by illumination and air movement under normal gravitational forces on the earth and to make an estimation of the temperature increase in reproductive organs in closed plant growth facilities under microgravity in space. Thermal images of reproductive organs of rice and strawberry were captured using infrared thermography at air temperatures of 10 11 °C. Compared to the air temperature, temperatures of petals, stigmas and anthers of strawberry increased by 24, 22 and 14 °C, respectively, after 5 min of lighting at an irradiance of 160 W m-2 from incandescent lamps. Temperatures of reproductive organs and leaves of strawberry were significantly higher than those of rice. The temperatures of petals, stigmas, anthers and leaves of strawberry decreased by 13, 12, 13 and 14 °C, respectively, when the air velocity was increased from 0.1 to 1.0 ms-1. These results show that air movement is necessary to reduce the temperatures of plant reproductive organs in plant growth facilities.

  4. Advertising to the enemy: enhanced floral fragrance increases beetle attraction and reduces plant reproduction.

    PubMed

    Theis, Nina; Adler, Lynn S

    2012-02-01

    Many organisms face challenges in avoiding predation while searching for mates. For plants, emitting floral fragrances to advertise reproductive structures could increase the attraction of detrimental insects along with pollinators. Very few studies have experimentally evaluated the costs and benefits of fragrance emission with explicit consideration of how plant fitness is affected by both pollinators and florivores. To determine the reproductive consequences of increasing the apparency of reproductive parts, we manipulated fragrance, pollination, and florivores in the wild Texas gourd, Cucurbita pepo var. texana. With enhanced fragrance we found an increase in the attraction of florivores, rather than pollinators, and a decrease in seed production. This study is the first to demonstrate that enhanced floral fragrance can increase the attraction of detrimental florivores and decrease plant reproduction, suggesting that florivory as well as pollination has shaped the evolution of floral scent. PMID:22624324

  5. TERRESTRIAL PLANT REPRODUCTIVE TESTING: SHOULD WILDLIFE TOXICOLOGISTS CARE?

    EPA Science Inventory

    Standard phytotoxicity testing using the seedling emergence and vegetative vigor tests have been shown to be inadequate for the protection of plant reproduction. Both experimental evidence and unintended field exposures have shown vegetation can be minimally or not significantly...

  6. Age, sex and reproductive status affect boldness in dogs.

    PubMed

    Starling, Melissa J; Branson, Nicholas; Thomson, Peter C; McGreevy, Paul D

    2013-09-01

    Boldness in dogs is believed to be one end of the shy-bold axis, representing a super-trait. Several personality traits fall under the influence of this super-trait. Previous studies have found that boldness is affected by breed and breed groups, influences performance in sporting dogs, and is affected in some cases by the sex of the dogs. This study investigated the effects of dog age, sex and reproductive status on boldness in dogs by way of a dog personality survey circulated amongst Australian dog owners. Age had a significant effect on boldness (F=4.476; DF=16,758; P<0.001), with boldness decreasing with age in years. Males were bolder than females (F=19.219; DF=1,758; P<0.001) and entire dogs were bolder than neutered dogs (F=4.330; DF=1,758; P<0.038). The study indicates how behaviour may change in adult dogs as they age and adds to the literature on how sex and reproductive status may affect personality in dogs. PMID:23778256

  7. Plant Reproduction. Plant Life in Action[TM]. Schlessinger Science Library. [Videotape].

    ERIC Educational Resources Information Center

    2000

    Plants are vital to all other life on this planet - without them, there would be no food, shelter or oxygen. Luckily, over millions of years plants have developed many different features in order to survive and reproduce. In Plant Reproduction, students will discover that primitive mosses and algae are dependent upon water for their reproduction.…

  8. ATP binding cassette G transporters and plant male reproduction.

    PubMed

    Zhao, Guochao; Shi, Jianxin; Liang, Wanqi; Zhang, Dabing

    2016-01-01

    The function of ATP Binding Cassette G (ABCG) transporters in the regulation of plant vegetative organs development has been well characterized in various plant species. In contrast, their function in reproductive development particularly male reproductive development received considerably less attention till some ABCG transporters was reported to be associated with anther and pollen wall development in Arabidopsis thaliana and rice (Oryza sativa) during the past decade. This mini-review summarizes current knowledge of ABCG transporters regarding to their roles in male reproduction and underlying genetic and biochemical mechanisms, which makes it evident that ABCG transporters represent one of those conserved and divergent components closely related to male reproduction in plants. This mini-review also discusses the current challenges and future perspectives in this particular field. PMID:26906115

  9. Callose synthesis during reproductive development in monocotyledonous and dicotyledonous plants

    PubMed Central

    Shi, Xiao; Han, Xiao; Lu, Tie-gang

    2016-01-01

    Callose, a linear β-1,3-glucan molecule, plays important roles in a variety of processes in angiosperms, including development and the response to biotic and abiotic stress. Despite the importance of callose deposition, our understanding of the roles of callose in rice reproductive development and the regulation of callose biosynthesis is limited. GLUCAN SYNTHASE-LIKE genes encode callose synthases (GSLs), which function in the production of callose at diverse sites in plants. Studies have shown that callose participated in plant reproductive development, and that the timely deposition and degradation of callose were essential for normal male gametophyte development. In this mini-review, we described conserved sequences found in GSL family proteins from monocotyledonous (Oryza sativa and Zea mays) and dicotyledonous (Arabidopsis thaliana and Glycine max) plants. We also describe the latest findings on callose biosynthesis and deposition during reproductive development and discuss future challenges in unraveling the mechanism of callose synthesis and deposition in higher plants. PMID:26451709

  10. Callose synthesis during reproductive development in monocotyledonous and dicotyledonous plants.

    PubMed

    Shi, Xiao; Han, Xiao; Lu, Tie-Gang

    2016-02-01

    Callose, a linear β-1,3-glucan molecule, plays important roles in a variety of processes in angiosperms, including development and the response to biotic and abiotic stress. Despite the importance of callose deposition, our understanding of the roles of callose in rice reproductive development and the regulation of callose biosynthesis is limited. GLUCAN SYNTHASE-LIKE genes encode callose synthases (GSLs), which function in the production of callose at diverse sites in plants. Studies have shown that callose participated in plant reproductive development, and that the timely deposition and degradation of callose were essential for normal male gametophyte development. In this mini-review, we described conserved sequences found in GSL family proteins from monocotyledonous (Oryza sativa and Zea mays) and dicotyledonous (Arabidopsis thaliana and Glycine max) plants. We also describe the latest findings on callose biosynthesis and deposition during reproductive development and discuss future challenges in unraveling the mechanism of callose synthesis and deposition in higher plants. PMID:26451709

  11. Simulated warming shifts the flowering phenology and sexual reproduction of Cardamine hirsuta under different Planting densities

    PubMed Central

    Cao, YuSong; Xiao, Yian; Huang, Haiqun; Xu, Jiancheng; Hu, Wenhai; Wang, Ning

    2016-01-01

    Climate warming can shift the reproductive phenology of plant, and hence dramatically reduced the reproductive capacity both of density-dependent and -independent plant species. But it is still unclear how climate warming affects flowering phenology and reproductive allocation of plant under different planting densities. Here, we assessed the impact of simulated warming on flowering phenology and sexual reproduction in the ephemeral herb Cardamine hirsuta under four densities. We found that simulated warming delayed the onset of flowering averagely for 3.6 days but preceded the end of flowering for about 1 day, which indicated climate warming shortened the duration of the flowering. And the flowering amplitude in the peak flowering day also dramatically increased in the simulated warming treatment, which caused a mass-flowering pattern. Climate warming significantly increased the weights of the fruits, seeds and seed, but reduced fruit length and sexual reproductive allocation under all the four densities. The duration of flowering was shortened and the weights of the fruits, seeds and seed, and sexual reproductive allocation were reduced under The highest density. PMID:27296893

  12. Simulated warming shifts the flowering phenology and sexual reproduction of Cardamine hirsuta under different Planting densities.

    PubMed

    Cao, YuSong; Xiao, Yian; Huang, Haiqun; Xu, Jiancheng; Hu, Wenhai; Wang, Ning

    2016-01-01

    Climate warming can shift the reproductive phenology of plant, and hence dramatically reduced the reproductive capacity both of density-dependent and -independent plant species. But it is still unclear how climate warming affects flowering phenology and reproductive allocation of plant under different planting densities. Here, we assessed the impact of simulated warming on flowering phenology and sexual reproduction in the ephemeral herb Cardamine hirsuta under four densities. We found that simulated warming delayed the onset of flowering averagely for 3.6 days but preceded the end of flowering for about 1 day, which indicated climate warming shortened the duration of the flowering. And the flowering amplitude in the peak flowering day also dramatically increased in the simulated warming treatment, which caused a mass-flowering pattern. Climate warming significantly increased the weights of the fruits, seeds and seed, but reduced fruit length and sexual reproductive allocation under all the four densities. The duration of flowering was shortened and the weights of the fruits, seeds and seed, and sexual reproductive allocation were reduced under The highest density. PMID:27296893

  13. From Flowers to Fruits: How Children's Books Represent Plant Reproduction

    ERIC Educational Resources Information Center

    Schussler, Elisabeth E.

    2008-01-01

    Children's trade books about science may be playing an increasing role in science instruction; however, the potential effects on student learning are unknown. To investigate whether a subset of books would be appropriate for classroom instruction about a specific science topic (plant reproduction), a selection of children's books about plants was…

  14. DEHP Impairs Zebrafish Reproduction by Affecting Critical Factors in Oogenesis

    PubMed Central

    Carnevali, Oliana; Tosti, Luca; Speciale, Claudia; Peng, Chun; Zhu, Yong; Maradonna, Francesca

    2010-01-01

    Public concerns on phthalates distributions in the environment have been increasing since they can cause liver cancer, structural abnormalities and reduce sperm counts in male reproductive system. However, few data are actually available on the effects of Di-(2-ethylhexyl)-phthalate (DEHP) in female reproductive system. The aim of this study was to assess the impacts of DEHP on zebrafish oogenesis and embryo production. Female Danio rerio were exposed to environmentally relevant doses of DEHP and a significant decrease in ovulation and embryo production was observed. The effects of DEHP on several key regulators of oocyte maturation and ovulation including bone morphogenetic protein-15 (BMP15), luteinizing hormone receptor (LHR), membrane progesterone receptors (mPRs) and cyclooxygenase (COX)-2 (ptgs2) were determined by real time PCR. The expressions of BMP15 and mPR proteins were further determined by Western analyses to strengthen molecular findings. Moreover, plasma vitellogenin (vtg) titers were assayed by an ELISA procedure to determine the estrogenic effects of DEHP and its effects on oocyte growth. A significant reduction of fecundity in fish exposed to DEHP was observed. The reduced reproductive capacity was associated with an increase in ovarian BMP15 levels. This rise, in turn, was concomitant with a significant reduction in LHR and mPRβ levels. Finally, ptgs2 expression, the final trigger of ovulation, was also decreased by DEHP. By an in vitro maturation assay, the inhibitory effect of DEHP on germinal vesicle breakdown was further confirmed. In conclusion, DEHP affecting signals involved in oocyte growth (vtg), maturation (BMP15, LHR, mPRs,) and ovulation (ptgs2), deeply impairs ovarian functions with serious consequences on embryo production. Since there is a significant genetic similarity between D.rerio and humans, the harmful effects observed at oocyte level may be relevant for further molecular studies on humans. PMID:20419165

  15. Reproductive consequences of mate quantity versus mate diversity in a wind-pollinated plant

    NASA Astrophysics Data System (ADS)

    Vandepitte, K.; Roldán-Ruiz, I.; Honnay, O.

    2009-07-01

    Since most pollen travels limited distances in wind-pollinated plants, both the local quantity and diversity of mates may limit female reproductive success. Yet little evidence exists on their relative contribution, despite the importance of viable seed production to population dynamics. To study how variation in female reproductive success is affected by the quantity versus the diversity of surrounding mates contributing pollen, we integrated pollination experiments, data on natural seed set and seed viability, and AFLP genetic marker data in the wind-pollinated dioecious clonal forest herb Mercurialis perennis. Pollination experiments indicated weak quantitative pollen limitation effects on seed set. Among-population crosses showed reduced seed viability, suggesting outbreeding depression due to genetic divergence. Pollination with pollen from a single source did not negatively affect reproductive success. These findings were consistent with results of the survey of natural female reproductive success. Seed set decreased with the distance to males in a female plants' local neighborhood, suggesting a shortage of pollen in isolated female plants, and increased with the degree of local genetic diversity. Spatial isolation to other populations and population size did not affect seed set. None of these variables were related to seed viability. We conclude that pollen movement in M. perennis is likely very limited. Both male proximity and the local degree of genetic diversity influenced female reproductive success.

  16. Fast-slow continuum and reproductive strategies structure plant life-history variation worldwide.

    PubMed

    Salguero-Gómez, Roberto; Jones, Owen R; Jongejans, Eelke; Blomberg, Simon P; Hodgson, David J; Mbeau-Ache, Cyril; Zuidema, Pieter A; de Kroon, Hans; Buckley, Yvonne M

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population performance. We show that 55% of the variation in plant life-history strategies is adequately characterized using two independent axes: the fast-slow continuum, including fast-growing, short-lived plant species at one end and slow-growing, long-lived species at the other, and a reproductive strategy axis, with highly reproductive, iteroparous species at one extreme and poorly reproductive, semelparous plants with frequent shrinkage at the other. Our findings remain consistent across major habitats and are minimally affected by plant growth form and phylogenetic ancestry, suggesting that the relative independence of the fast-slow and reproduction strategy axes is general in the plant kingdom. Our findings have similarities with how life-history strategies are structured in mammals, birds, and reptiles. The position of plant species populations in the 2D space produced by both axes predicts their rate of recovery from disturbances and population growth rate. This life-history framework may complement trait-based frameworks on leaf and wood economics; together these frameworks may allow prediction of responses of plants to anthropogenic disturbances and changing environments. PMID:26699477

  17. Fast–slow continuum and reproductive strategies structure plant life-history variation worldwide

    PubMed Central

    Salguero-Gómez, Roberto; Jones, Owen R.; Jongejans, Eelke; Blomberg, Simon P.; Hodgson, David J.; Mbeau-Ache, Cyril; Zuidema, Pieter A.; de Kroon, Hans; Buckley, Yvonne M.

    2016-01-01

    The identification of patterns in life-history strategies across the tree of life is essential to our prediction of population persistence, extinction, and diversification. Plants exhibit a wide range of patterns of longevity, growth, and reproduction, but the general determinants of this enormous variation in life history are poorly understood. We use demographic data from 418 plant species in the wild, from annual herbs to supercentennial trees, to examine how growth form, habitat, and phylogenetic relationships structure plant life histories and to develop a framework to predict population performance. We show that 55% of the variation in plant life-history strategies is adequately characterized using two independent axes: the fast–slow continuum, including fast-growing, short-lived plant species at one end and slow-growing, long-lived species at the other, and a reproductive strategy axis, with highly reproductive, iteroparous species at one extreme and poorly reproductive, semelparous plants with frequent shrinkage at the other. Our findings remain consistent across major habitats and are minimally affected by plant growth form and phylogenetic ancestry, suggesting that the relative independence of the fast–slow and reproduction strategy axes is general in the plant kingdom. Our findings have similarities with how life-history strategies are structured in mammals, birds, and reptiles. The position of plant species populations in the 2D space produced by both axes predicts their rate of recovery from disturbances and population growth rate. This life-history framework may complement trait-based frameworks on leaf and wood economics; together these frameworks may allow prediction of responses of plants to anthropogenic disturbances and changing environments. PMID:26699477

  18. Plant reproductive traits mediate tritrophic feedback effects within an obligate brood-site pollination mutualism.

    PubMed

    Krishnan, Anusha; Ghara, Mahua; Kasinathan, Srinivasan; Pramanik, Gautam Kumar; Revadi, Santosh; Borges, Renee M

    2015-11-01

    Plants, herbivores and parasitoids affect each other directly and indirectly; however, feedback effects mediated by host plant traits have rarely been demonstrated in these tritrophic interactions. Brood-site pollination mutualisms (e.g. those involving figs and fig wasps) represent specialised tritrophic communities where the progeny of mutualistic pollinators and of non-mutualistic gallers (both herbivores) together with that of their parasitoids develop within enclosed inflorescences called syconia (hence termed brood-sites or microcosms). Plant reproductive phenology (which affects temporal brood-site availability) and inflorescence size (representing brood-site size) are plant traits that could affect reproductive resources, and hence relationships between trees, pollinators and non-pollinating wasps. Analysing wasp and seed contents of syconia, we examined direct, indirect, trophic and non-trophic relationships within the interaction web of the fig-fig wasp community of Ficus racemosa in the context of brood site size and availability. We demonstrate that in addition to direct resource competition and predator-prey (host-parasitoid) interactions, these communities display exploitative or apparent competition and trait-mediated indirect interactions. Inflorescence size and plant reproductive phenology impacted plant-herbivore and plant-parasitoid associations. These plant traits also influenced herbivore-herbivore and herbivore-parasitoid relationships via indirect effects. Most importantly, we found a reciprocal effect between within-tree reproductive asynchrony and fig wasp progeny abundances per syconium that drives a positive feedback cycle within the system. The impact of a multitrophic feedback cycle within a community built around a mutualistic core highlights the need for a holistic view of plant-herbivore-parasitoid interactions in the community ecology of mutualisms. PMID:26160003

  19. Symbiotic regulation of plant growth, development and reproduction

    USGS Publications Warehouse

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  20. Plant Reproduction: Self-Incompatibility to Go.

    PubMed

    Tovar-Mendez, Alejandro; McClure, Bruce

    2016-02-01

    In a new study, the Papaver rhoeas (poppy family) self-incompatibility system has been transferred into Arabidopsis thaliana, a distantly related plant with a very different floral structure. The simple poppy self-incompatibility system may finally make it possible to introduce this potentially valuable trait into any plant. PMID:26859267

  1. Structural Dynamic and Desiccation Damage in Plant reproductive Organs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant reproductive structures provide ideal systems to study the impact of water loss on cellular systems. Diverse physiologies in related taxa or among different organs (e.g., leaves, overwintering structures, pollen and embryos) allow us to compare sensitivities among structures and identify prima...

  2. The Role of Gravity on the Reproduction of Arabidopsis Plants

    NASA Technical Reports Server (NTRS)

    Hoshizaki, T.

    1985-01-01

    The presence of gravity as a necessary environmental factor for higher plants to complete their life cycle was examined. Arabidopsis thalliana (L.) Heynh. Columbia strain plants were grown continuously for three generations in a simulated micro-g environment as induced by horizontal clinostats. Growth, development and reproduction were followed. The Arabidopsis plants were selected for three generations on clinostats because: (1) a short life cycle of around 35 days; (2) the cells of third generation plants would in theory be free of gravity imprint; and (3) a third generation plant would therefore more than likely grow and respond like a plant growing in a micro-g environment. It is found that gravity is not a required environmental factor for higher plants to complete their life cycle, at least as tested by a horizontal clinostat. Clinostatting does not prevent the completion of the plant life cycle. However, clinostatting does appear to slow down the reproductive process of Arabidopsis plants. Whether higher plants can continue to reproduce for many generations in a true micro-g environment of space can only be determined by long duration experiments in space.

  3. Reproduction on orbit by plants in the Brassicaceae family

    NASA Astrophysics Data System (ADS)

    Musgrave, Mary E.; Kuang, Anxiu; Xiao, Ying; Matthews, Sharon W.

    1999-01-01

    Previous studies on growth and development during spaceflight had indicated that the transition from vegetative to reproductive growth was particularly difficult for plants. Our objective has been to study how the spaceflight environment impacts the different steps in plant reproduction. This goal has been pursued in two general ways: by using plants that had been pre-grown to the flowering stage on earth, and by using plants that developed completely on orbit. Our objectives have been met by a combination of experiments that required essentially no crew time on orbit, and those that required an extensive commitment of crew time. The plants chosen for the studies were closely related members of the family Brassicaceae: Arabidopsis thaliana and Brassica rapa. In a series of short-duration experiments with Arabidopsis on the space shuttle we found that depletion of carbon dioxide in closed chambers resulted in aborted development of both the male and female reproductive apparatus in microgravity. Normal development was restored by addition of carbon dioxide or by providing air flow. A subsequent shuttle experiment with Brassica utilizing hardware that provides a vigorous air flow confirmed embryo development following pollination on orbit. Brassica plants grown from seed on the Mir space station produced seed that germinated and grew when replanted on orbit. Future experiments will determine effects of multiple generations in space.

  4. Roles of autophagy in male reproductive development in plants

    PubMed Central

    Hanamata, Shigeru; Kurusu, Takamitsu; Kuchitsu, Kazuyuki

    2014-01-01

    Autophagy, a major catabolic pathway in eukaryotic cells, is essential in development, maintenance of cellular homeostasis, immunity and programmed cell death (PCD) in multicellular organisms. In plant cells, autophagy plays roles in recycling of proteins and metabolites including lipids, and is involved in many physiological processes such as abiotic and biotic stress responses. However, its roles during reproductive development had remained poorly understood. Quantitative live cell imaging techniques for the autophagic flux and genetic studies in several plant species have recently revealed significant roles of autophagy in developmental processes, regulation of PCD and lipid metabolism. We here review the novel roles of autophagic fluxes in plant cells, and discuss their possible significance in PCD and metabolic regulation, with particular focus on male reproductive development during the pollen maturation. PMID:25309556

  5. Promoting Reproductive Options for HIV-Affected Couples in Sub-Saharan Africa

    PubMed Central

    Mmeje, Okeoma; Cohen, Craig R.; Murage, Alfred; Ong’ech, John; Kiarie, James; van der Poel, Sheryl

    2014-01-01

    HIV-affected couples have unique challenges that require access to information and reproductive services which prevent HIV transmission to the uninfected partner and offspring while allowing couples to fulfill their reproductive goals. In high HIV prevalent regions of sub-Saharan Africa, HIV-affected couples require multipurpose prevention technologies (MPTs) to enhance their reproductive healthcare options beyond contraception and prevention of HIV/sexually transmitted infections (STIs) to include assistance in childbearing. The unique characteristics of the condom and its accepted use in conjunction with safer conception interventions allow HIV-serodiscordant couples an opportunity to maintain reproductive health, prevent HIV/STI transmission, and achieve their reproductive goals while timing conception. Rethinking the traditional view of the condom and incorporating a broader reproductive health perspective of HIV-affected couples into MPT methodologies will impact demand, acceptability, and uptake of these future technologies. PMID:25335844

  6. Tracking Official Development Assistance for Reproductive Health in Conflict-Affected Countries

    PubMed Central

    Patel, Preeti; Roberts, Bayard; Guy, Samantha; Lee-Jones, Louise; Conteh, Lesong

    2009-01-01

    Background Reproductive health needs are particularly acute in countries affected by armed conflict. Reliable information on aid investment for reproductive health in these countries is essential for improving the efficiency and effectiveness of aid. The purpose of this study was to analyse official development assistance (ODA) for reproductive health activities in conflict-affected countries from 2003 to 2006. Methods and Findings The Creditor Reporting System and the Financial Tracking System databases were the chosen data sources for the study. ODA disbursement for reproductive health activities to 18 conflict-affected countries was analysed for 2003, 2004, 2005, and 2006. An average of US$20.8 billion in total ODA was disbursed annually to the 18 conflict-affected countries between 2003 and 2006, of which US$509.3 million (2.4%) was allocated to reproductive health. This represents an annual average of US$1.30 disbursed per capita in the 18 sampled countries for reproductive health activities. Non-conflict-affected least-developed countries received 53.3% more ODA for reproductive health activities than conflict-affected least-developed countries, despite the latter generally having greater reproductive health needs. ODA disbursed for HIV/AIDS prevention and treatment increased by 119.4% from 2003 to 2006. The ODA disbursed for other direct reproductive health activities declined by 35.9% over the same period. Conclusions This study provides evidence of inequity in disbursement of reproductive health ODA between conflict-affected countries and non-conflict-affected countries, and between different reproductive health activities. These findings and the study's recommendations seek to support initiatives to make aid financing more responsive to need in the context of armed conflict. PMID:19513098

  7. Effects of light intensity light quality and air velocity on temperature in plant reproductive organs

    NASA Astrophysics Data System (ADS)

    Kitaya, Y.; Hirai, H.

    Excess temperature increase in plant reproductive organs such as anthers and stigmata could cause fertility impediments and thus produce sterile seeds under artificial lighting conditions in closed plant growth facilities There is a possibility that the aberration was caused by an excess increase in temperatures of reproductive organs in Bioregenerative Life Support Systems under microgravity conditions in space The fundamental study was conducted to know the thermal situation of the plant reproductive organs as affected by light intensity light quality and air velocity on the earth and to estimate the excess temperature increase in the reproductive organs in closed plant growth facilities in space Thermal images of reproductive organs of rice and strawberry were captured using infrared thermography at an air temperature of 10 r C The temperatures in flowers at 300 mu mol m -2 s -1 PPFD under the lights from red LEDs white LEDs blue LEDs fluorescent lamps and incandescent lamps increased by 1 4 1 7 1 9 6 0 and 25 3 r C respectively for rice and by 2 8 3 4 4 1 7 8 and 43 4 r C respectively for strawberry The flower temperatures increased with increasing PPFD levels The temperatures in petals anthers and stigmas of strawberry at 300 mu mol m -2 s -1 PPFD under incandescent lamps increased by 32 7 29 0 and 26 6 r C respectively at 0 1 m s -1 air velocity and by 20 6 18 5 and 15 9 r C respectively at 0 8 m s -1 air velocity The temperatures of reproductive organs decreased with increasing

  8. Legal issues affecting confidentiality and informed consent in reproductive health.

    PubMed

    Rockett, L R

    2000-01-01

    The law governing confidentiality and informed consent has acquired unique characteristics in the area of reproductive health, as a consequence of both the establishment of a constitutional right to privacy in reproductive health matters and the reaction of those politically and morally opposed to the exercise of that right. The primary issues have involved: 1) the right of minors to receive reproductive health services without parental consent, which remains a political battleground; 2) laws requiring physicians to provide information to pregnant patients that is intended, not to inform them of the risks and benefits of the procedure, but to discourage them from obtaining abortions; 3) coerced and prohibited sterilizations; 4) court-ordered contraception and procedures to protect the fetus; and 5) restrictions on counseling about abortion, contraception, sterilization, and other reproductive health services authorized by state conscience or noncompliance clauses that shield such restrictions from the usual ethical, medical, and legal rules governing informed consent. The last area is of profound significance to the ability of women to make informed decisions about their reproductive health options. In the current economic environment, which fuels mergers and acquisitions involving sectarian and nonsectarian institutions, women are increasingly being put at risk as a result of such restrictions. PMID:11070641

  9. Allopregnanolone as a Mediator of Affective Switching in Reproductive Mood Disorders

    PubMed Central

    Schiller, Crystal Edler; Schmidt, Peter J.; Rubinow, David R.

    2014-01-01

    Rationale Reproductive mood disorders, including premenstrual dysphoria (PMD) and postpartum depression (PPD), are characterized by affective dysregulation that occurs during specific reproductive states. The occurrence of illness onset during changes in reproductive endocrine function has generated interest in the role of gonadal steroids in the pathophysiology of reproductive mood disorders, yet the mechanisms by which the changing hormone milieu triggers depression in susceptible women remain poorly understood. Objectives This review focuses on one of the neurosteroid metabolites of progesterone – allopregnanolone (ALLO) – that acutely regulates neuronal function and may mediate affective dysregulation that occurs concomitant with changes in reproductive endocrine function. We describe the role of the ‘neuroactive’ steroids estradiol and progesterone in reproductive endocrine-related mood disorders to highlight the potential mechanisms by which ALLO might contribute to their pathophysiology. Finally, using existing data, we test the hypothesis that changes in ALLO levels may trigger affective dysregulation in susceptible women. Results Although there is no reliable evidence that basal ALLO levels distinguish those with PMD or PPD from those without, existing animal models suggest potential mechanisms by which specific reproductive states may unmask susceptibility to affective dysregulation. Consistent with these models, initially euthymic women with PMD and those with a history of PPD show a negative association between depressive symptoms and circulating ALLO levels following progesterone administration. Conclusions Existing animal models and our own preliminary data suggest that ALLO may play an important role in the pathophysiology of reproductive mood disorders by triggering affective dysregulation in susceptible women. PMID:24846476

  10. Calcium signaling during reproduction and biotrophic fungal interactions in plants.

    PubMed

    Chen, Junyi; Gutjahr, Caroline; Bleckmann, Andrea; Dresselhaus, Thomas

    2015-04-01

    Many recent studies have indicated that cellular communications during plant reproduction, fungal invasion, and defense involve identical or similar molecular players and mechanisms. Indeed, pollen tube invasion and sperm release shares many common features with infection of plant tissue by fungi and oomycetes, as a tip-growing intruder needs to communicate with the receptive cells to gain access into a cell and tissue. Depending on the compatibility between cells, interactions may result in defense, invasion, growth support, or cell death. Plant cells stimulated by both pollen tubes and fungal hyphae secrete, for example, small cysteine-rich proteins and receptor-like kinases are activated leading to intracellular signaling events such as the production of reactive oxygen species (ROS) and the generation of calcium (Ca(2+)) transients. The ubiquitous and versatile second messenger Ca(2+) thereafter plays a central and crucial role in modulating numerous downstream signaling processes. In stimulated cells, it elicits both fast and slow cellular responses depending on the shape, frequency, amplitude, and duration of the Ca(2+) transients. The various Ca(2+) signatures are transduced into cellular information via a battery of Ca(2+)-binding proteins. In this review, we focus on Ca(2+) signaling and discuss its occurrence during plant reproduction and interactions of plant cells with biotrophic filamentous microbes. The participation of Ca(2+) in ROS signaling pathways is also discussed. PMID:25660409

  11. NADPH Oxidase-Dependent Superoxide Production in Plant Reproductive Tissues.

    PubMed

    Jiménez-Quesada, María J; Traverso, José Á; Alché, Juan de Dios

    2016-01-01

    In the life cycle of a flowering plant, the male gametophyte (pollen grain) produced in the anther reaches the stigmatic surface and initiates the pollen-pistil interaction, an important step in plant reproduction, which ultimately leads to the delivery of two sperm cells to the female gametophyte (embryo sac) inside the ovule. The pollen tube undergoes a strictly apical expansion characterized by a high growth rate, whose targeting should be tightly regulated. A continuous exchange of signals therefore takes place between the haploid pollen and diploid tissue of the pistil until fertilization. In compatible interactions, theses processes result in double fertilization to form a zygote (2n) and the triploid endosperm. Among the large number of signaling mechanisms involved, the redox network appears to be particularly important. Respiratory burst oxidase homologs (Rbohs) are superoxide-producing enzymes involved in a broad range of processes in plant physiology. In this study, we review the latest findings on understanding Rboh activity in sexual plant reproduction, with a particular focus on the male gametophyte from the anther development stages to the crowning point of fertilization. Rboh isoforms have been identified in both the male and female gametophyte and have proven to be tightly regulated. Their role at crucial points such as proper growth of pollen tube, self-incompatibility response and eventual fertilization is discussed. PMID:27066025

  12. NADPH Oxidase-Dependent Superoxide Production in Plant Reproductive Tissues

    PubMed Central

    Jiménez-Quesada, María J.; Traverso, José Á.; Alché, Juan de Dios

    2016-01-01

    In the life cycle of a flowering plant, the male gametophyte (pollen grain) produced in the anther reaches the stigmatic surface and initiates the pollen–pistil interaction, an important step in plant reproduction, which ultimately leads to the delivery of two sperm cells to the female gametophyte (embryo sac) inside the ovule. The pollen tube undergoes a strictly apical expansion characterized by a high growth rate, whose targeting should be tightly regulated. A continuous exchange of signals therefore takes place between the haploid pollen and diploid tissue of the pistil until fertilization. In compatible interactions, theses processes result in double fertilization to form a zygote (2n) and the triploid endosperm. Among the large number of signaling mechanisms involved, the redox network appears to be particularly important. Respiratory burst oxidase homologs (Rbohs) are superoxide-producing enzymes involved in a broad range of processes in plant physiology. In this study, we review the latest findings on understanding Rboh activity in sexual plant reproduction, with a particular focus on the male gametophyte from the anther development stages to the crowning point of fertilization. Rboh isoforms have been identified in both the male and female gametophyte and have proven to be tightly regulated. Their role at crucial points such as proper growth of pollen tube, self-incompatibility response and eventual fertilization is discussed. PMID:27066025

  13. Plant reproduction in the Central Amazonian floodplains: challenges and adaptations

    PubMed Central

    Ferreira, Cristiane Silva; Piedade, Maria Teresa Fernandez; de Oliveira Wittmann, Astrid; Franco, Augusto César

    2010-01-01

    Background The Central Amazonian floodplain forests are subjected to extended periods of flooding and to flooding amplitudes of 10 m or more. The predictability, the length of the flood pulse, the abrupt transition in the environmental conditions along topographic gradients on the banks of major rivers in Central Amazonia, and the powerful water and sediment dynamics impose a strong selective pressure on plant reproduction systems. Scope In this review, we examine how the hydrological cycle influences the strategies of sexual and asexual reproduction in herbaceous and woody plants. These are of fundamental importance for the completion of the life cycle. Possible constraints to seed germination, seedling establishment and formation of seed banks are also covered. Likewise, we also discuss the importance of river connectivity for species propagation and persistence in floodplains. Conclusions The propagation and establishment strategies employed by the highly diversified assortment of different plant life forms result in contrasting successional stages and a zonation of plant assemblages along the flood-level gradient, whose species composition and successional status are continuously changing not only temporally but also spatially along the river channel. PMID:22476067

  14. Getting the right traits: reproductive and dispersal characteristics predict the invasiveness of herbaceous plant species.

    PubMed

    Moravcová, Lenka; Pyšek, Petr; Jarošík, Vojtěch; Pergl, Jan

    2015-01-01

    To better understand the effect of species traits on plant invasion, we collected comparative data on 20 reproductive and dispersal traits of 93 herbaceous alien species in the Czech Republic, central Europe, introduced after 1500 A. D. We explain plant invasion success, expressed by two measures: invasiveness, i.e. whether the species is naturalized but non-invasive, or invasive; and dominance in plant communities expressed as the mean cover in vegetation plots. We also tested how important reproductive and dispersal traits are in models including other characteristics generally known to predict invasion outcome, such as plant height, life history and residence time. By using regression/classification trees we show that the biological traits affect invasion success at all life stages, from reproduction (seed production) to dispersal (propagule properties), and the ability to compete with resident species (height). By including species traits information not usually available in multispecies analyses, we provide evidence that traits do play important role in determining the outcome of invasion and can be used to distinguish between alien species that reach the final stage of the invasion process and dominate the local communities from those that do not. No effect of taxonomy ascertained in regression and classification trees indicates that the role of traits in invasiveness should be assessed primarily at the species level. PMID:25906399

  15. Getting the Right Traits: Reproductive and Dispersal Characteristics Predict the Invasiveness of Herbaceous Plant Species

    PubMed Central

    Moravcová, Lenka; Pyšek, Petr; Pergl, Jan

    2015-01-01

    To better understand the effect of species traits on plant invasion, we collected comparative data on 20 reproductive and dispersal traits of 93 herbaceous alien species in the Czech Republic, central Europe, introduced after 1500 A. D. We explain plant invasion success, expressed by two measures: invasiveness, i.e. whether the species is naturalized but non-invasive, or invasive; and dominance in plant communities expressed as the mean cover in vegetation plots. We also tested how important reproductive and dispersal traits are in models including other characteristics generally known to predict invasion outcome, such as plant height, life history and residence time. By using regression/classification trees we show that the biological traits affect invasion success at all life stages, from reproduction (seed production) to dispersal (propagule properties), and the ability to compete with resident species (height). By including species traits information not usually available in multispecies analyses, we provide evidence that traits do play important role in determining the outcome of invasion and can be used to distinguish between alien species that reach the final stage of the invasion process and dominate the local communities from those that do not. No effect of taxonomy ascertained in regression and classification trees indicates that the role of traits in invasiveness should be assessed primarily at the species level. PMID:25906399

  16. Assessment of wastewater treatment plant effluent effects on fish reproduction

    EPA Science Inventory

    Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds that can affect hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined t...

  17. Water availability and population origin affect the expression of the tradeoff between reproduction and growth in Plantago coronopus.

    PubMed

    Hansen, C F; García, M B; Ehlers, B K

    2013-05-01

    Investment in reproduction and growth represent a classic tradeoff with implication for life history evolution. The local environment can play a major role in the magnitude and evolutionary consequences of such a tradeoff. Here, we examined the investment in reproductive and vegetative tissue in 40 maternal half-sib families from four different populations of the herb Plantago coronopus growing in either a dry or wet greenhouse environment. Plants originated from populations with an annual or a perennial life form, with annuals prevailing in drier habitats with greater seasonal variation in both temperature and precipitation. We found that water availability affected the expression of the tradeoff (both phenotypic and genetic) between reproduction and growth, being most accentuated under dry condition. However, populations responded very differently to water treatments. Plants from annual populations showed a similar response to drought condition with little variation among maternal families, suggesting a history of selection favouring genotypes with high allocation to reproduction when water availability is low. Plants from annual populations also expressed the highest level of plasticity. For the perennial populations, one showed a large variation among maternal families in resource allocation and expressed significant negative genetic correlations between reproductive and vegetative biomass under drought. The other perennial population showed less variation in response to treatment and had trait values similar to those of the annuals, although it was significantly less plastic. We stress the importance of considering intraspecific variation in response to environmental change such as drought, as conspecific plants exhibited very different abilities and strategies to respond to high versus low water availability even among geographically close populations. PMID:23621367

  18. Oyster reproduction is affected by exposure to polystyrene microplastics.

    PubMed

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  19. Oyster reproduction is affected by exposure to polystyrene microplastics

    PubMed Central

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (−38%), diameter (−5%), and sperm velocity (−23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  20. Convergence beyond flower morphology? Reproductive biology of hummingbird-pollinated plants in the Brazilian Cerrado.

    PubMed

    Ferreira, C; Maruyama, P K; Oliveira, P E

    2016-03-01

    Convergent reproductive traits in non-related plants may be the result of similar environmental conditions and/or specialised interactions with pollinators. Here, we documented the pollination and reproductive biology of Bionia coriacea (Fabaceae), Esterhazya splendida (Orobanchaceae) and Ananas ananassoides (Bromeliaceae) as case studies in the context of hummingbird pollination in Cerrado, the Neotropical savanna of Central South America. We combined our results with a survey of hummingbird pollination studies in the region to investigate the recently suggested association of hummingbird pollination and self-compatibility. Plant species studied here differed in their specialisation for ornithophily, from more generalist A. ananassoides to somewhat specialist B. coriacea and E. splendida. This continuum of specialisation in floral traits also translated into floral visitor composition. Amazilia fimbriata was the most frequent pollinator for all species, and the differences in floral display and nectar energy availability among plant species affect hummingbirds' behaviour. Most of the hummingbird-pollinated Cerrado plants (60.0%, n = 20), including those studied here, were self-incompatible, in contrast to other biomes in the Neotropics. Association to more generalist, often territorial, hummingbirds, and resulting reduced pollen flow in open savanna areas may explain predominance of self-incompatibility. But it is possible that mating system is more associated with the predominance of woody hummingbird plants in the Cerrado plant assemblage than to the pollination system itself. PMID:26370490

  1. Effects of short-term grazing exclusion on plant phenology and reproductive succession in a Tibetan alpine meadow

    PubMed Central

    Zhu, Juntao; Zhang, Yangjian; Liu, Yaojie

    2016-01-01

    Grazing exclusion (GE) has been widely considered as an effective avenue for restoring degraded grasslands throughout the world. GE, via modifying abiotic and biotic environments, inevitably affects phenological development. A five-year manipulative experiment was conducted in a Tibetan alpine meadow to examine the effects of GE on phenological processes and reproductive success. The study indicated that GE strongly affected phenological development of alpine plant species. Specifically, the low-growing, shallow-rooted species (LSS), such as Kobresia pygmaea, are more sensitive to GE-caused changes on upper-soil moisture and light. GE advanced each phonological process of K. pygmaea, except in the case of the treatment of fencing for 5 years (F5), which postponed the reproductive stage and lowered the reproductive success of K. pygmaea. Increased soil moisture triggered by GE, especially in the upper soil, may stimulate growth of LSS. However, the thick litter layer under the F5 treatment can influence the photoperiod of LSS, resulting in suppression of its reproductive development. These findings indicate that plant traits associated with resource acquisition, such as rooting depth and plant height, mediate plant phenology and reproductive responses to grazing exclusion treatments. PMID:27301554

  2. Effects of short-term grazing exclusion on plant phenology and reproductive succession in a Tibetan alpine meadow.

    PubMed

    Zhu, Juntao; Zhang, Yangjian; Liu, Yaojie

    2016-01-01

    Grazing exclusion (GE) has been widely considered as an effective avenue for restoring degraded grasslands throughout the world. GE, via modifying abiotic and biotic environments, inevitably affects phenological development. A five-year manipulative experiment was conducted in a Tibetan alpine meadow to examine the effects of GE on phenological processes and reproductive success. The study indicated that GE strongly affected phenological development of alpine plant species. Specifically, the low-growing, shallow-rooted species (LSS), such as Kobresia pygmaea, are more sensitive to GE-caused changes on upper-soil moisture and light. GE advanced each phonological process of K. pygmaea, except in the case of the treatment of fencing for 5 years (F5), which postponed the reproductive stage and lowered the reproductive success of K. pygmaea. Increased soil moisture triggered by GE, especially in the upper soil, may stimulate growth of LSS. However, the thick litter layer under the F5 treatment can influence the photoperiod of LSS, resulting in suppression of its reproductive development. These findings indicate that plant traits associated with resource acquisition, such as rooting depth and plant height, mediate plant phenology and reproductive responses to grazing exclusion treatments. PMID:27301554

  3. Prey selectivity affects reproductive success of a corallivorous reef fish.

    PubMed

    Brooker, Rohan M; Jones, Geoffrey P; Munday, Philip L

    2013-06-01

    Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists. PMID:23124333

  4. Plant functional traits mediate reproductive phenology and success in response to experimental warming and snow addition in Tibet.

    PubMed

    Dorji, Tsechoe; Totland, Orjan; Moe, Stein R; Hopping, Kelly A; Pan, Jianbin; Klein, Julia A

    2013-02-01

    Global climate change is predicted to have large impacts on the phenology and reproduction of alpine plants, which will have important implications for plant demography and community interactions, trophic dynamics, ecosystem energy balance, and human livelihoods. In this article we report results of a 3-year, fully factorial experimental study exploring how warming, snow addition, and their combination affect reproductive phenology, effort, and success of four alpine plant species belonging to three different life forms in a semiarid, alpine meadow ecosystem on the central Tibetan Plateau. Our results indicate that warming and snow addition change reproductive phenology and success, but responses are not uniform across species. Moreover, traits associated with resource acquisition, such as rooting depth and life history (early vs. late flowering), mediate plant phenology, and reproductive responses to changing climatic conditions. Specifically, we found that warming delayed the reproductive phenology and decreased number of inflorescences of Kobresia pygmaea C. B. Clarke, a shallow-rooted, early-flowering plant, which may be mainly constrained by upper-soil moisture availability. Because K. pygmaea is the dominant species in the alpine meadow ecosystem, these results may have important implications for ecosystem dynamics and for pastoralists and wildlife in the region. PMID:23504784

  5. Plant toxins that affect nicotinic acetylcholine receptors: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants produce wide variety of chemical compounds termed secondary metabolites that are not involved in basic metabolism, photosynthesis or reproduction. These compounds are used as flavors, fragrances, insecticides, dyes, hallucinogens, nutritional supplements, poisons, and pharmaceutical agents. ...

  6. Nectar alkaloids decrease pollination and female reproduction in a native plant.

    PubMed

    Adler, Lynn S; Irwin, Rebecca E

    2012-04-01

    The evolution of floral traits may be shaped by a community of floral visitors that affect plant fitness, including pollinators and floral antagonists. The role of nectar in attracting pollinators has been extensively studied, but its effects on floral antagonists are less understood. Furthermore, the composition of non-sugar nectar components, such as secondary compounds, may affect plant reproduction via changes in both pollinator and floral antagonist behavior. We manipulated the nectar alkaloid gelsemine in wild plants of the native perennial vine Gelsemium sempervirens. We crossed nectar gelsemine manipulations with a hand-pollination treatment, allowing us to determine the effect of both the trait and the interaction on plant female reproduction. We measured pollen deposition, pollen removal, and nectar robbing to assess whether gelsemine altered the behavior of mutualists and antagonists. High nectar gelsemine reduced conspecific pollen receipt by nearly half and also reduced the proportion of conspecific pollen grains received, but had no effect on nectar robbing. Although high nectar gelsemine reduced pollen removal, an estimate of male reproduction, by one-third, this effect was not statistically significant. Fruit set was limited by pollen receipt. However, this effect varied across sites such that the sites that were most pollen-limited were also the sites where nectar alkaloids had the least effect on pollen receipt, resulting in no significant effect of nectar alkaloids on fruit set. Finally, high nectar gelsemine significantly reduced seed weight; however, this effect was mediated by a mechanism other than pollen limitation. Taken together, our work suggests that nectar alkaloids are more costly than beneficial in our system, and that relatively small-scale spatial variation in trait effects and interactions could determine the selective impacts of traits such as nectar composition. PMID:22011842

  7. Effects of invasive plant species on pollinator service and reproduction in native plants at Acadia National Park

    USGS Publications Warehouse

    Stubbs, C.J.; Drummond, F.; Ginsberg, H.

    2007-01-01

    Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for nectar and pollen. The effects of invasive plant species on pollinator behavior were investigated by comparing pollinator visitation to co-flowering native and invasive species with visitation to native species growing alone. The effect of invasives on pollination of native plants was studied by comparing fruit set in patches of the native species growing near invasives with patches far from invasive species in Acadia National Park. The coflowering pairs were as follows: in the spring native Vaccinium angustifolium (lowbush blueberry) was paired with B. thunbergii; in early summer native Viburnum nudum (wild raisin) was paired with F. alnus ; in late summer native Spiraea alba (meadowsweet) was paired with L. salicaria. We investigated whether these invasives competed with native plants for pollinators in Acadia and thus negatively affected native plant reproduction. Our objectives were to determine: 1) the influence, if any, of each invasive on pollinator visitation to a co-flowering native species, 2) factors that might affect visitation, 3) invasive pollen transfer to native plants, and 4) whether invasives influence native plant reproduction (fruit set). Our findings indicate that at times the number of flower visitors to natives was lower or the species composition of visitors different when invasives were present, that invasives sometimes attracted more pollinators, that generally the invasives were more rewarding as far as nectar and pollen availability for pollinators, and that generally native plant fruit set and seed set was not significantly lowered in the presence of

  8. Genetic causes of transitions from sexual reproduction to asexuality in plants and animals.

    PubMed

    Neiman, M; Sharbel, T F; Schwander, T

    2014-07-01

    The persistence of sexual reproduction in the face of competition from asexual invaders is more likely if asexual lineages are produced infrequently or have low fitness. The generation rate and success of new asexual lineages will be influenced by the proximate mechanisms underlying transitions to asexuality. As such, characterization of these mechanisms can help explain the distribution of reproductive modes among natural populations. Here, we synthesize the literature addressing proximate causes of transitions from sexual to asexual reproduction in plants and animals. In cyclical and facultatively asexual taxa, individual mutations can cause obligate asexuality. The evolution of asexuality in obligately sexual groups is more complex, requiring the simultaneous acquisition of two traits generally controlled by different genetic factors: unreduced gamete formation and spontaneous development of unfertilized gametes. At least three 'pre-adaptations' could favour transitions to obligate asexuality in obligate sexuals. First, linkage among loci affecting separate key components of asexuality facilitates its spread, with evidence for these linkage blocks in plants. Second, asexuality should evolve more readily in haplodiploids; support for this hypothesis comes from two examples where a single locus causes transitions to asexuality. Third, standing genetic variation for the production of unreduced gametes could facilitate transitions to asexuality, but whether the ability to produce unreduced gametes contributes to the evolution of obligate asexuality remains unclear. We close by reviewing the associations between asexuality, hybridization and polyploidy, and argue that current data suggest that hybridization is more likely to play a causal role in transitions to asexuality than polyploidy. PMID:24666600

  9. The Influence of Plant Anatomy on Oviposition and Reproductive Success of the Omnivorous Bug, Orius Insidiosus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms whereby plant characteristics influence the reproductive behavior and immature survival of omnivorous insects are poorly understood. We examined how trichome density and internal anatomy of five plant species influence the oviposition behavior of zoophytophagous Orius insidiosus and t...

  10. The reproduction in women affected by cooley disease

    PubMed Central

    Pafumi, Carlo; Leanza, Vito; Coco, Luana; Vizzini, Stefania; Ciotta, Lilliana; Messina, Alessandra; Leanza, Gianluca; Zarbo, Giuseppe; D'Agati, Alfio; Palumbo, Marco Antonio; Iemmola, Alessandra; Gulino, Ferdinando Antonio; Teodoro, Maria Cristina; Attard, Matthew; Plesca, Alina Cristina; Soares, Catarina; Kouloubis, Nina; Chammas, Mayada

    2011-01-01

    The health background management and outcomes of 5 pregnancies in 4 women affected by Cooley Disease, from Paediatric Institute of Catania University, are described, considering the preconceptual guidances and cares for such patients. These patients were selected among a group of 100 thalassemic women divided into three subgroups, according to their first and successive menstruation characteristics: i) patients with primitive amenorrhoea, ii) patients with secondary amenorrhoea and iii) patients with normal menstruation. Only one woman, affected by primitive amenorrhoea, needed the induction of ovulation. A precise and detailed pre-pregnancy assessment was effected before each conception. This was constituted by a series of essays, including checks for diabetes and hypothyroidism, for B and C hepatitis and for blood group antibodies. Moreover were evaluated: cardiac function, rubella immunity and transaminases. Other pregnancy monitoring, and cares during labour and delivery were effected according to usual obstetrics practice. All the women were in labour when she were 38 week pregnant, and the outcome were five healthy babies born at term, weighting between 2600 and 3200gs. The only complication was the Caesarean section. The improvements of current treatments, especially in the management of iron deposits, the prolongation of survival rate, will result in a continuous increase of pregnancies in thalassemic women. Pregnancy is now a real possibility for women affected by such disease. We are furthermore studying the possibility to collect the fetus' umbilical cord blood, after the delivery, to attempt eterologus transplantation to his mother trying to get a complete marrow reconstitution. PMID:22184526

  11. Direct effects of energy-related air pollutants on plant sexual reproduction

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  12. Plant Reproduction and the Pollen Tube Journey--How the Females Lure the Males

    ERIC Educational Resources Information Center

    Lorbiecke, Rene

    2012-01-01

    The growth of pollen tubes is one of the most characteristic events in angiosperm reproduction. This article describes an activity for visualizing the journey and guidance of pollen tubes in the reproductive structures of a flowering plant. The activity uses a semi-in vivo system with rapid-cycling "Brassica rapa," also known as Fast Plants.…

  13. Optimizing reproductive phenology in a two-resource world: a dynamic allocation model of plant growth predicts later reproduction in phosphorus-limited plants

    PubMed Central

    Nord, Eric A.; Shea, Katriona; Lynch, Jonathan P.

    2011-01-01

    Background and Aims Timing of reproduction is a key life-history trait that is regulated by resource availability. Delayed reproduction in soils with low phosphorus availability is common among annuals, in contrast to the accelerated reproduction typical of other low-nutrient environments. It is hypothesized that this anomalous response arises from the high marginal value of additional allocation to root growth caused by the low mobility of phosphorus in soils. Methods To better understand the benefits and costs of such delayed reproduction, a two-resource dynamic allocation model of plant growth and reproduction is presented. The model incorporates growth, respiration, and carbon and phosphorus acquisition of both root and shoot tissue, and considers the reallocation of resources from senescent leaves. The model is parameterized with data from Arabidopsis and the optimal reproductive phenology is explored in a range of environments. Key Results The model predicts delayed reproduction in low-phosphorus environments. Reproductive timing in low-phosphorus environments is quite sensitive to phosphorus mobility, but is less sensitive to the temporal distribution of mortality risks. In low-phosphorus environments, the relative metabolic cost of roots was greater, and reproductive allocation reduced, compared with high-phosphorus conditions. The model suggests that delayed reproduction in response to low phosphorus availability may be reduced in plants adapted to environments where phosphorus mobility is greater. Conclusions Delayed reproduction in low-phosphorus soils can be a beneficial response allowing for increased acquisition and utilization of phosphorus. This finding has implications both for efforts to breed crops for low-phosphorus soils, and for efforts to understand how climate change may impact plant growth and productivity in low-phosphorus environments. PMID:21712299

  14. Density-dependent reproductive and vegetative allocation in the aquatic plant Pistia stratiotes (Araceae).

    PubMed

    Coelho, Flávia Freitas; Deboni, Liene; Lopes, Frederico Santos

    2005-01-01

    Pistia stratiotes is an aquatic macrophyte that grows in temporary-ponds in the southern Pantanal, Brazil. It reproduces both sexually and asexually and is usually observed forming dense mats on the water surface, a condition favored by the plant's vegetative reproduction coupled with an ability for rapid growth. In this study we examined the effect of densely crowded conditions on the production of reproductive and vegetative structures. In addition, we verified whether there is a trade-off between clonal growth and investment in sexual reproductive structures, and whether there is an allocation pattern with plant size. Individual plant biomass and the number of the rosettes producing sexual reproductive structures and vegetative growth structures both increased with density. Increase in plant size resulted in increased proportional allocation to sexual reproductive structures and vegetative growth structures. Allocation of biomass to reproduction did not occur at the expense of clonal growth. Thus, the density response appears as a increase of rosettes producing sexual reproductive structures and vegetative growth structures. Therefore, long leaves and stolons may be adaptive under densely crowded conditions where competition for light is intense. An important aspect in the study of trade-offs is the size-dependency of the allocation patterns .Usually, larger plants produce more biomass. Therefore, larger plants can allocate more biomass to both vegetative and sexual reproduction than smaller plants and thus show a positive correlation between both traits rather than the expected negative one. PMID:17354448

  15. Pollinator limitation and the effect of breeding systems on plant reproduction in forest fragments

    NASA Astrophysics Data System (ADS)

    Nayak, K. Geetha; Davidar, Priya

    2010-03-01

    Reproduction of plants in fragmented habitats may be limited because of lower diversity or abundance of pollinators, and/or variation in local plant density. We assessed natural fruit set and pollinator limitation in ten species of woody plants in natural and restored fragments in the Pondicherry region of southern India, to see whether breeding system of plants (self-compatible and self-incompatible) affected fruit set. We tested whether the number of flowering individuals in the fragments affected the fruit set and further examined the adult and sapling densities of self-compatible (SC) and self-incompatible (SI) species. We measured the natural level of fruit set and pollinator limitation (calculated as the difference in fruit set between hand cross-pollinated and naturally pollinated flowers). Our results demonstrate that there was a higher level of pollinator limitation and hence lower levels of natural fruit set in self-incompatible species as compared to self-compatible species. However, the hand cross-pollinated flowers in SC and SI species produced similar levels of fruit set, further indicating that lower fruit set was due to pollinator limitation and not due to lack of cross-compatible individuals in the fragments. There was no significant relation between number of flowering individuals and the levels of natural fruit set, except for two species Derris ovalifolia, Ixora pavetta. In these species the natural fruit set decreased with increasing population size, again indicating pollinator limitation. The adult and sapling densities in self-compatible species were significantly higher than in self-incompatible species. These findings indicate that the low reproductive output in self-incompatible species may eventually lead to lower population sizes. Restoration of pollinator services along with plant species in fragmented habitats is important for the long-term conservation of biodiversity.

  16. Population Densities, Vegetation Green-Up, and Plant Productivity: Impacts on Reproductive Success and Juvenile Body Mass in Reindeer

    PubMed Central

    Tveraa, Torkild; Stien, Audun; Bårdsen, Bård-J.; Fauchald, Per

    2013-01-01

    Global warming is expected to cause earlier springs and increased primary productivity in the Arctic. These changes may improve food availability for Arctic herbivores, but may also have negative effects by generating a mismatch between the surge of high quality food in the spring and the timing of reproduction. We analyzed a 10 year dataset of satellite derived measures of vegetation green-up, population densities, calf body masses and female reproductive success in 19 reindeer (Rangifer tarandus) populations in Northern Norway. An early onset of spring and high peak plant productivity had positive effects on calf autumn body masses and female reproductive success. In addition, body masses and reproductive success were both negatively related to population density. The quantity of food available, as determined by the onset of vegetation green-up and plant productivity over the summer were the main drivers of body mass growth and reproductive success. We found no evidence for an effect of the speed of spring green-up. Nor did we detect a negative mismatch between early springs and subsequent recruitment. Effects of global warming on plant productivity and onset of spring is likely to positively affect sub-Arctic reindeer. PMID:23451049

  17. How female education affects reproductive behavior in urban Pakistan.

    PubMed

    Sathar, Z A; Mason, K O

    1993-01-01

    Although Pakistan remains in a pretransitional stage (contraceptive prevalence of only 11.9% among married women in 1992), urban women with post-primary levels of education are spearheading the gradual move toward fertility transition. Data collected in the city of Karachi in 1987 were used to determine whether the inverse association between fertility and female education is attributable to child supply variables, demand factors, or fertility regulation costs. Karachi, with its high concentration of women with secondary educations employed in professional occupations, has a contraceptive prevalence rate of 31%. Among women married for less than 20 years, a 10-year increment in education predicts that a woman will average two-fifths of a child less than other women in the previous 5 years. Regression analysis identified 4 significant intervening variables in the education-fertility relationship: marriage duration, net family income, formal sector employment, and age at first marriage. Education appears to affect fertility because it promotes a later age at marriage and thus reduces life-time exposure to the risk of childbearing, induces women to marry men with higher incomes (a phenomenon that either reduces the cost of fertility regulation or the demand for children), leads women to become employed in the formal sector (leading to a reduction in the demand for children), and has other unspecified effects on women's values or opportunities that are captured by their birth cohort. When these intervening variables are held constant, women's attitude toward family planning loses its impact on fertility, as do women's domestic autonomy and their expectations of self-support in old age. These findings lend support to increased investments in female education in urban Pakistan as a means of limiting the childbearing of married women. Although it is not clear if investment in female education would have the same effect in rural Pakistan, such action is important from a

  18. Development and reproduction of Panonychus citri (Prostigmata: Tetranychidae) on different species and varieties of citrus plants.

    PubMed

    Zanardi, Odimar Zanuzo; Bordini, Gabriela Pavan; Franco, Aline Aparecida; de Morais, Matheus Rovere; Yamamoto, Pedro Takao

    2015-12-01

    The species and varieties of citrus plants that are currently grown can favor the population growth of the citrus red mite Panonychus citri (McGregor) (Prostigmata: Tetranychidae) and alter the pest management programs in citrus groves. In this study we evaluated, in the laboratory, the development and reproduction of P. citri and estimated its life table parameters when reared on four varieties of Citrus sinensis (L.) Osbeck (Valencia, Pera, Natal, and Hamlin), one variety of Citrus reticulata Blanco (Ponkan) and one variety of Citrus limon (L.) Burm. (Sicilian). The incubation period and egg viability were not affected by the host plant. However, the development and survival of the immature stage were significantly lower on Hamlin orange than on Valencia, Pera and Natal oranges, Ponkan mandarin and Sicilian lemon. The fecundity and oviposition period of females were lower on Hamlin orange than on the other hosts. Mites reared on Valencia orange and Sicilian lemon had a higher net reproductive rate (R 0 ), intrinsic growth rate (r) and finite rate of increase (λ), and a shorter interval between generations (T) than on Pera, Natal and Hamlin oranges and Ponkan mandarin. On the other hand, mites reared on Hamlin orange had the lowest R 0 , r and λ and the highest T among the hosts. Based on the results obtained we recommend that for Valencia orange and Sicilian lemon, the mite monitoring programs should be more intense to detect the initial infestation of pest, avoiding the damage in plants and the increase in production costs. PMID:26459376

  19. [A sociological study of factors affecting reproductive health of female teenagers and young women].

    PubMed

    Nizamov, I G; Chechulina, O V

    2003-01-01

    The reproductive health of teenagers deserves a special attention and must be regarded from the viewpoint of their future prospects as well as their social and cultural media. The mentioned social-and-cultural factors affecting the teenagers' attitude towards sexuality and preconditioning their access to information and services of healthcare have an impact on the status of their reproductive health and on their general well-being, including the ability of teenagers to avoid an undesired pregnancy or sexually transmitted diseases. PMID:12882120

  20. Evaluating the Interacting Influences of Pollination, Seed Predation, Invasive Species and Isolation on Reproductive Success in a Threatened Alpine Plant

    PubMed Central

    Krushelnycky, Paul D.

    2014-01-01

    Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai’i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0–55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10–20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting

  1. The disadvantages of mating outside home: How breeding in captivity affects the reproductive success of seahorses?

    NASA Astrophysics Data System (ADS)

    Faleiro, Filipa; Narciso, Luís

    2013-04-01

    In captivity, husbandry conditions are distinct from those experienced by fish in the wild and may have a significant effect on reproductive success. This study evaluates the effect of supportive breeding (i.e., breeding animals in captivity using wild parents) on some quantitative and qualitative aspects of the reproductive success of the long-snouted seahorse, Hippocampus guttulatus. Wild and captive broods were compared in terms of juvenile number, size, condition and fatty acid profile at birth. Reproductive investment and breeding success of H. guttulatus decreased considerably in captivity. Juveniles from captive broods were fewer in number, smaller, generally thinner and with lower fatty acid contents (per juvenile) than those from wild broods, although their fatty acid composition (μg mg- 1 DW or %TFA) was not significantly affected. Although not greatly encouraging, the poor reproductive performance of captive seahorses should not, however, efface the potential of supportive breeding as a tool for seahorse conservation. Enhanced conditions and long-term breeding in captivity will allow to improve the reproductive success of the species and the quality of the fingerlings.

  2. Toxic plants: Effects on reproduction and fetal and embryonic development in livestock

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reproductive performance not only relates to an animal’s ability to produce offspring, but to produce it at a proper time interval and provide proper neonatal care and nutrition. The recognition that poisonous plants may have a major impact on reproductive performance is relatively new and not full...

  3. Prepubertal tamoxifen treatment affects development of heifer reproductive tissues and related signaling pathways.

    PubMed

    Al Naib, A; Tucker, H L M; Xie, G; Keisler, D H; Bartol, F F; Rhoads, R P; Akers, R M; Rhoads, M L

    2016-07-01

    Prepubertal exposure of the developing ovaries and reproductive tract (RT) to estrogen or xenoestrogens can have acute and long-term consequences that compromise the reproductive performance of cattle. This research examined effects of the selective estrogen receptor modulator tamoxifen (TAM) on gene and protein abundance in prepubertal ovaries and RT, with a particular focus on signaling pathways that affect morphology. Tamoxifen was administered to Holstein heifer calves (n=8) daily (0.3mg/kg subcutaneously) from 28 to 120 d of age, when tissues were collected. Control calves (n=7) received an equal volume of excipient. Weight, gross measurements, and samples of reproductive tissues were collected, and protein and mRNA were extracted from snap-frozen samples of vagina, cervix, uterus, oviduct, ovary, and liver. Neither estradiol nor insulin-like growth factor I (IGFI) concentrations in the serum were affected by TAM treatment. Tamoxifen treatment reduced ovarian weight independently from effects on antral follicle populations, as there was no difference in visible antral follicle numbers on the day of collection. Estrogen receptor α (ESR1) and β (ESR2) mRNA, ESR1 protein, IGFI, progesterone receptor, total growth hormone receptor, WNT4, WNT5A, and WNT7A mRNA, in addition to mitogen-activated protein kinase (MAPK) and phosphorylated MAPK proteins were affected differently depending on the tissue examined. However, neither IGFI receptor mRNA nor protein abundance were affected by TAM treatment. Results indicate that reproductive development in prepubertal Holstein heifer calves is TAM-sensitive, and that bovine RT and ovarian development are supported, in part, by estrogen receptor-dependent mechanisms during the period studied here. Potential long-term consequences of such developmental disruption remain to be defined. PMID:27085397

  4. Scale-dependent feedbacks between patch size and plant reproduction in desert grassland

    USGS Publications Warehouse

    Svejcar, Lauren N.; Bestelmeyer, Brandon T.; Duniway, Michael C.; James, Darren K.

    2015-01-01

    Theoretical models suggest that scale-dependent feedbacks between plant reproductive success and plant patch size govern transitions from highly to sparsely vegetated states in drylands, yet there is scant empirical evidence for these mechanisms. Scale-dependent feedback models suggest that an optimal patch size exists for growth and reproduction of plants and that a threshold patch organization exists below which positive feedbacks between vegetation and resources can break down, leading to critical transitions. We examined the relationship between patch size and plant reproduction using an experiment in a Chihuahuan Desert grassland. We tested the hypothesis that reproductive effort and success of a dominant grass (Bouteloua eriopoda) would vary predictably with patch size. We found that focal plants in medium-sized patches featured higher rates of grass reproductive success than when plants occupied either large patch interiors or small patches. These patterns support the existence of scale-dependent feedbacks in Chihuahuan Desert grasslands and indicate an optimal patch size for reproductive effort and success in B. eriopoda. We discuss the implications of these results for detecting ecological thresholds in desert grasslands.

  5. The Importance of Pollinator Generalization and Abundance for the Reproductive Success of a Generalist Plant

    PubMed Central

    Maldonado, María Belén; Lomáscolo, Silvia Beatriz; Vázquez, Diego Pedro

    2013-01-01

    Previous studies have examined separately how pollinator generalization and abundance influence plant reproductive success, but none so far has evaluated simultaneously the relative importance of these pollinator attributes. Here we evaluated the extent to which pollinator generalization and abundance influence plant reproductive success per visit and at the population level on a generalist plant, Opuntia sulphurea (Cactaceae). We used field experiments and path analysis to evaluate whether the per-visit effect is determined by the pollinator’s degree of generalization, and whether the population level effect (pollinator impact) is determined by the pollinator’s degree of generalization and abundance. Based on the models we tested, we concluded that the per-visit effect of a pollinator on plant reproduction was not determined by the pollinators’ degree of generalization, while the population-level impact of a pollinator on plant reproduction was mainly determined by the pollinators’ degree of generalization. Thus, generalist pollinators have the greatest species impact on pollination and reproductive success of O. sulphurea. According to our analysis this greatest impact of generalist pollinators may be partly explained by pollinator abundance. However, as abundance does not suffice as an explanation of pollinator impact, we suggest that vagility, need for resource consumption, and energetic efficiency of generalist pollinators may also contribute to determine a pollinator’s impact on plant reproduction. PMID:24116049

  6. Plant invasion phenomenon enhances reproduction performance in an endangered spider

    NASA Astrophysics Data System (ADS)

    Pétillon, Julien; Puzin, Charlène; Acou, Anthony; Outreman, Yannick

    2009-10-01

    Current models in evolutionary ecology predict life history alterations in response to habitat suitability to optimize fitness. Only few empirical studies have demonstrated how life history traits that are expected to trade off against each other differ among environments. In Europe, many salt marshes have been recently invaded by the grass Elymus athericus. Previous studies however showed higher densities of the endangered spider Arctosa fulvolineata (Araneae: Lycosidae) in invaded salt marshes compared to natural habitats, which suggests a lower habitat suitability in the latter. The aim of this study was to determine if this emerging habitat (1) affects the amount of resource acquisition and (2) alters the balance between life history traits that are expected to trade off against each other in this stenotopic salt marsh species. As suggested by theoretical studies, an optimization of fitness by increasing egg size at the cost of decreasing fecundity in unsuitable (i.e., natural) habitats was expected. Females presenting cocoon were then collected in close invaded and natural salt marsh areas within the Mont Saint-Michel Bay (France). By considering female mass as covariate, cocoon mass, number of eggs, and egg volume were compared between both habitats. Clutch mass was strongly determined by female mass in both habitats. Clutch mass was however significantly smaller in the natural habitat compared to the invaded habitat, indicating a higher resource acquisition in the latter. When correcting for female size, fecundity was additionally increased in the invaded habitat through a significant decrease in egg size. This phenotypic response can be explained by differences in habitat structure between invaded and natural habitats: the former offers a more complex litter favoring nocturnal wanderers like A. fulvolineata. The existence of such an adaptive reproduction strategy depending on habitat suitability constitutes an original case of an invasion that favors an

  7. Depressing Antidepressant: Fluoxetine Affects Serotonin Neurons Causing Adverse Reproductive Responses in Daphnia magna.

    PubMed

    Campos, Bruno; Rivetti, Claudia; Kress, Timm; Barata, Carlos; Dircksen, Heinrich

    2016-06-01

    Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants. As endocrine disruptive contaminants in the environment, SSRIs affect reproduction in aquatic organisms. In the water flea Daphnia magna, SSRIs increase offspring production in a food ration-dependent manner. At limiting food conditions, females exposed to SSRIs produce more but smaller offspring, which is a maladaptive life-history strategy. We asked whether increased serotonin levels in newly identified serotonin-neurons in the Daphnia brain mediate these effects. We provide strong evidence that exogenous SSRI fluoxetine selectively increases serotonin-immunoreactivity in identified brain neurons under limiting food conditions thereby leading to maladaptive offspring production. Fluoxetine increases serotonin-immunoreactivity at low food conditions to similar maximal levels as observed under high food conditions and concomitantly enhances offspring production. Sublethal amounts of the neurotoxin 5,7-dihydroxytryptamine known to specifically ablate serotonin-neurons markedly decrease serotonin-immunoreactivity and offspring production, strongly supporting the effect to be serotonin-specific by reversing the reproductive phenotype attained under fluoxetine. Thus, SSRIs impair serotonin-regulation of reproductive investment in a planktonic key organism causing inappropriately increased reproduction with potentially severe ecological impact. PMID:27128505

  8. Hippocampal morphology is differentially affected by reproductive experience in the mother.

    PubMed

    Pawluski, Jodi L; Galea, Liisa A M

    2006-01-01

    Pregnancy and mothering result in a number of hormonal, neurological, and behavioral changes that are necessary to ensure reproductive success. With subsequent reproductive experience (multiparity and mothering), further neurological and behavioral changes may result. Recent research has shown that previous motherhood enhances both hippocampus-dependent learning and memory and long-term potentiation (LTP); together with decreases in hippocampus volumes during pregnancy it is suggested that the hippocampus is affected by pregnancy and/or mothering. The present experiment aimed to investigate the effect of reproductive experience (nulli, primi-, and multiparity and mothering) on dendritic morphology in the CA1 and CA3 regions of the hippocampus. Brains were stained with a modified version of the single-section Golgi impregnation technique, and dendritic length, number of branch points, and spine density was analyzed for apical and basal regions of CA1 and CA3 pyramidal neurons. Primiparity and/or mothering resulted in dendritic remodeling in both the CA1 and CA3 hippocampal regions, and multiparity resulted in enhanced spine density in the basal CA1 region, which was positively correlated with number of male pups in a litter. These findings point to the effect of reproductive experience and offspring on plasticity in the hippocampus, an area not traditionally associated with motherhood. PMID:16216005

  9. The impact of sulfur dioxide on plant sexual reproduction: in vivo and in vitro effects compared

    SciTech Connect

    DuBay, D.T.; Murdy, W.H.

    1983-01-01

    In Lepidium virginicum L., exposure of pollen to 0.6 ppm sulfur dioxide (SO/sub 2/) for 4 h reduced pollen germination in vitro 94% from the control, whereas exposure to 0.6 ppm SO/sub 2/ for 2, 4, and 8 h during flowering reduced pollen germination in vivo 50% from the control, but did not affect seed set.An interaction between SO/sub 2/ and water may have caused the inhibition of pollen germination in a liquid culture medium, as well as on the moist surface of an intact stigma. However, the results suggest that the use of pollen germination and pollen tube elongation in vitro to asses the direct effects of SO/sub 2/ on plant sexual reproduction in vivo is not valid.

  10. Plant-based porcine reproductive and respiratory syndrome virus VLPs induce an immune response in mice.

    PubMed

    Uribe-Campero, Laura; Monroy-García, Alberto; Durán-Meza, Ana L; Villagrana-Escareño, María V; Ruíz-García, Jaime; Hernández, Jesús; Núñez-Palenius, Héctor G; Gómez-Lim, Miguel A

    2015-10-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) significantly affects the swine industry worldwide. An efficient, protective vaccine is still lacking. Here, we report for the first time the generation and purification of PRRSV virus like particles (VLPs) by expressing GP5, M and N genes in Nicotiana silvestris plants. The particles were clearly visible by transmission electron microscopy (TEM) with a size of 60-70 nm. Hydrodynamic diameter of the particles was obtained and it was confirmed that the VLPs had the appropriate size for PRRS virions and that the VLPs were highly pure. By measuring the Z potential we described the electrophoretic mobility behavior of VLPs and the best conditions for stability of the VLPs were determined. The particles were immunogenic in mice. A western blot of purified particles allowed detection of three coexpressed genes. These VLPs may serve as a platform to develop efficient PRRSV vaccines. PMID:26412521

  11. Medicinal plants used in Northern Peru for reproductive problems and female health

    PubMed Central

    2010-01-01

    Infections of the reproductive tract, complications after childbirth, and reproductive problems continue to be a major health challenge worldwide. An impressive number of plant species is traditionally used to remedy such afflictions, and some have been investigated for their efficacy with positive results. A total of 105 plant species belonging to 91 genera and 62 families were documented and identified as herbal remedies for reproductive problems in Northern Peru. Most species used were Asteraceae (9.52%), followed by Lamiaceae and Fabaceae (8.57% and 6.67%). The most important families are clearly represented very similarly to their overall importance in the local pharmacopoeia. The majority of herbal preparations for reproductive afflictions were prepared from the leaves of plants (22.72%), the whole plant (21.97%), and stems (21.21%), while other plant parts were used less frequently. More than 60% of the cases fresh plant material was used to prepare remedies. Over 70% of the remedies were applied orally, while the remaining ones were applied topically. Many remedies were prepared as mixtures of multiple ingredients. Little scientific evidence exists to prove the efficacy of the species employed as reproductive disorder remedies in Northern Peru. Only 34% of the plants found or their congeners have been studied at all for their medicinal properties. The information gained on frequently used traditional remedies might give some leads for future targets for further analysis in order to develop new drugs. PMID:21040536

  12. Caterpillar biomass depends on temperature and precipitation, but does not affect bird reproduction

    NASA Astrophysics Data System (ADS)

    Schöll, Eva Maria; Ohm, Judith; Hoffmann, Konstantin Frank; Hille, Sabine Marlene

    2016-07-01

    Complex changes in phenological events appear as temperatures are increasing: In deciduous forests bud burst, hatching of herbivorous caterpillars, egg laying and nestling time of birds when feeding chicks on caterpillars, may differentially shift into early season and alter synchronization. If timing of bird reproduction has to match with short periods of food availability, phenological mismatch could negatively affect reproductive success. Using a unique empirical approach along an altitudinal temperature gradient, we firstly asked whether besides temperature, also precipitation and leaf phenology interplay and affect caterpillar biomass, since impacts of rainfall on caterpillars have been largely neglected so far. Secondly, we asked whether abundance of caterpillars and thereby body mass of great tit nestlings, which are mainly fed with caterpillars, vary along the altitudinal temperature gradient. We demonstrated that next to temperature also precipitation and leaf phenology affected caterpillar biomass. In our beech forest, even along altitudes, caterpillars were available throughout the great tit breeding season but in highly variable amounts. Our findings revealed that although timing of leaf phenology and great tit breeding season were delayed with decreasing temperature, caterpillars occurred synchronously and were not delayed according to altitude. However, altitude negatively affected caterpillar biomass, but body mass of fledglings at high altitude sites was not affected by lower amounts of caterpillar biomass. This might be partially outweighed by larger territory sizes in great tits.

  13. Interactions for pollinator visitation and their consequences for reproduction in a plant community

    NASA Astrophysics Data System (ADS)

    Hegland, Stein Joar; Totland, Ørjan

    2012-08-01

    Competition and facilitation in species interactions attract much attention in ecology, but their relative importance has seldom been evaluated in a community context. We assessed competitive and facilitative interactions for pollinator visitation among co-flowering species in a plant community, investigated the subsequent consequences for plant reproduction, and investigated whether effects could be trait-based. We removed the flowers of two species attractive to pollinators, in two separate experiments and assessed the effects on pollinator visitation rates and components of reproductive success in 11 co-flowering focal herb species. Overall, most focal species appear not to interact with the removal species with respect to pollinator visitation and subsequent reproduction (neutral interactions). Three focal species in the community had significantly higher reproductive responses (fruit production and seed weight) in the presence of the attractive removal species (facilitative interactions), but species interaction effects were less pronounced in species' flower visitation rates. A community-wide meta-analysis demonstrated that the two experiments did not have a significant effect on either facilitation or competition, and that there was no overall correlation between effect sizes for visitation and reproduction. Based on species-specific responses, it seems likely that floral traits such as similar flower colors contribute to interspecific facilitation of pollinator visitation and, in particular, that high pollinator dependence for plant reproduction, and associated pollen limitation, may contribute to subsequent interaction effects on reproduction in the focal species.

  14. Between-Population Outbreeding Affects Plant Defence

    PubMed Central

    Leimu, Roosa; Fischer, Markus

    2010-01-01

    Between-population crosses may replenish genetic variation of populations, but may also result in outbreeding depression. Apart from direct effects on plant fitness, these outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and between-population outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for outbreeding depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect outbreeding depression in resistance and/or outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population outbreeding effects on tolerance range from outbreeding depression to outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact of outbreeding on the joint evolution of resistance and tolerance, and on the evolution of multiple defence strategies. PMID:20838662

  15. CO2 and fertility affect growth and reproduction but not susceptibility to aphids in field grown Solanum ptycanthum

    SciTech Connect

    Long, T.M.

    1995-09-01

    In general, C3 annual plants respond positively in terms of growth, reproduction and biomass accrued when grown under elevated levels of atmospheric carbon dioxide. However, most studies documenting this response have been conducted in growth chambers where plants can be reared under conditions free form environmental stressors such as nutrient and water constraints, UV exposure and damage from pests. During the 1993 fieldseason, I grew 200 individuals of Solanum ptycanthum in an array of 10 outdoor, open-topped CO2 enclosures (5 @ 700 ppm CO2) at the University of Michigan Biological Station in Pellston, MI. Half of the plants were grown in a 50;50 mix of native C-horizon soil and topsoil (low fertility); the other half were grown in 100% topsoil (high-fertility). Plants were censused throughout the growing season for flower and fruit production, growth rate and degree of infestation of aphids. Fertility and CO2 both significantly affected production of flowers and fruits, but only fertility was significantly related to vegetative growth. Aphid infestation varied significantly among enclosures, but was not related to CO2 or fertility.

  16. Unveiling the Redox Control of Plant Reproductive Development during Abiotic Stress

    PubMed Central

    Zinta, Gaurav; Khan, Asif; AbdElgawad, Hamada; Verma, Vipasha; Srivastava, Ashish Kumar

    2016-01-01

    Plants being sessile in nature are often challenged to various abiotic stresses including temperature fluctuations, water supply, salinity, and nutrient availability. Exposure of plants to such environmental perturbations result in the formation of reactive oxygen species (ROS) in cells. To scavenge ROS, enzymatic and molecular antioxidants are produced at a cellular level. ROS act as a signaling entity at lower concentrations maintaining normal growth and development, but if their levels increase beyond certain threshold, they produce toxic effects in plants. Some developmental stages, such as development of reproductive organs are more sensitive to abiotic stress than other stages of growth. As success of plant reproductive development is directly correlated with grain yield, stresses coinciding with reproductive phase results in the higher yield losses. In this article, we summarize the redox control of plant reproductive development, and elaborate how redox homeostasis is compromised during abiotic stress exposure. We highlight why more emphasis should be given to understand redox control of plant reproductive organ development during abiotic stress exposure96to engineer crops with better crop yield. We specifically discuss the role of ROS as a signaling molecule and its cross-talk with other signaling molecules such as hormones and sugars. PMID:27379102

  17. Unveiling the Redox Control of Plant Reproductive Development during Abiotic Stress.

    PubMed

    Zinta, Gaurav; Khan, Asif; AbdElgawad, Hamada; Verma, Vipasha; Srivastava, Ashish Kumar

    2016-01-01

    Plants being sessile in nature are often challenged to various abiotic stresses including temperature fluctuations, water supply, salinity, and nutrient availability. Exposure of plants to such environmental perturbations result in the formation of reactive oxygen species (ROS) in cells. To scavenge ROS, enzymatic and molecular antioxidants are produced at a cellular level. ROS act as a signaling entity at lower concentrations maintaining normal growth and development, but if their levels increase beyond certain threshold, they produce toxic effects in plants. Some developmental stages, such as development of reproductive organs are more sensitive to abiotic stress than other stages of growth. As success of plant reproductive development is directly correlated with grain yield, stresses coinciding with reproductive phase results in the higher yield losses. In this article, we summarize the redox control of plant reproductive development, and elaborate how redox homeostasis is compromised during abiotic stress exposure. We highlight why more emphasis should be given to understand redox control of plant reproductive organ development during abiotic stress exposure96to engineer crops with better crop yield. We specifically discuss the role of ROS as a signaling molecule and its cross-talk with other signaling molecules such as hormones and sugars. PMID:27379102

  18. Live-cell analysis of plant reproduction: live-cell imaging, optical manipulation, and advanced microscopy technologies.

    PubMed

    Kurihara, Daisuke; Hamamura, Yuki; Higashiyama, Tetsuya

    2013-05-01

    Sexual reproduction ensures propagation of species and enhances genetic diversity within populations. In flowering plants, sexual reproduction requires complicated and multi-step cell-to-cell communications among male and female cells. However, the confined nature of plant reproduction processes, which occur in the female reproductive organs and several cell layers of the pistil, limits our ability to observe these events in vivo. In this review, we discuss recent live-cell imaging in in vitro systems and the optical manipulation techniques that are used to capture the dynamic mechanisms representing molecular and cellular communications in sexual plant reproduction. PMID:23438900

  19. Why cellular communication during plant reproduction is particularly mediated by CRP signalling.

    PubMed

    Bircheneder, Susanne; Dresselhaus, Thomas

    2016-08-01

    Secreted cysteine-rich peptides (CRPs) represent one of the main classes of signalling peptides in plants. Whereas post-translationally modified small non-CRP peptides (psNCRPs) are mostly involved in signalling events during vegetative development and interactions with the environment, CRPs are overrepresented in reproductive processes including pollen germination and growth, self-incompatibility, gamete activation and fusion as well as seed development. In this opinion paper we compare the involvement of both types of peptides in vegetative and reproductive phases of the plant lifecycle. Besides their conserved cysteine pattern defining structural features, CRPs exhibit hypervariable primary sequences and a rapid evolution rate. As a result, CRPs represent a pool of highly polymorphic signalling peptides involved in species-specific functions during reproduction and thus likely represent key players to trigger speciation in plants by supporting reproductive isolation. In contrast, precursers of psNCRPs are proteolytically processed into small functional domains with high sequence conservation and act in more general processes. We discuss parallels in downstream processes of CRP signalling in both reproduction and defence against pathogenic fungi and alien pollen tubes, with special emphasis on the role of ROS and ion channels. In conclusion we suggest that CRP signalling during reproduction in plants has evolved from ancient defence mechanisms. PMID:27382112

  20. Does the inclusion of protease inhibitors in the insemination extender affect rabbit reproductive performance?

    PubMed

    Casares-Crespo, L; Vicente, J S; Talaván, A M; Viudes-de-Castro, M P

    2016-03-15

    The bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases. Thus, the addition of aminopeptidase inhibitors to rabbit semen extenders could be a solution to decrease the hormone degradation. This study was conducted to evaluate the effect of the protease activity inhibition on rabbit semen quality parameters and reproductive performance after artificial insemination. Seminal quality was not affected by the incubation with protease inhibitors, being the values of motility, viability, and acrosome integrity not significantly different between the protease inhibitors and the control group. In addition, seminal plasma aminopeptidase activity was inhibited in a 55.1% by the protease inhibitors. On the other hand, regarding the effect of protease inhibitors on reproductive performance, our results showed that the presence of protease inhibitors affected the prolificacy rate (9.2 ± 0.26 and 9.3 ± 0.23 vs. 8.2 ± 0.22 total born per litter for negative control, positive control, and aminopeptidase inhibitors group, respectively; P < 0.05), having this group one kit less per delivery. We conclude that the addition of a wide variety of protease inhibitors in the rabbit semen extender negatively affects prolificacy rate. Therefore, the development of new extenders with specific aminopeptidase inhibitors would be one of the strategies to increase the bioavailability of GnRH analogues without affecting the litter size. PMID:26639641

  1. You are what you eat: food limitation affects reproductive fitness in a sexually cannibalistic praying mantid.

    PubMed

    Barry, Katherine L

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  2. You Are What You Eat: Food Limitation Affects Reproductive Fitness in a Sexually Cannibalistic Praying Mantid

    PubMed Central

    Barry, Katherine L.

    2013-01-01

    Resource limitation during the juvenile stages frequently results in developmental delays and reduced size at maturity, and dietary restriction during adulthood can affect longevity and reproductive output. Variation in food intake can also result in alteration to the normal pattern of resource allocation among body parts or life-history stages. My primary aim in this study was to determine how varying juvenile and/or adult feeding regimes affect particular female and male traits in the sexually cannibalistic praying mantid Pseudomantis albofimbriata. Praying mantids are sit-and-wait predators whose resource intake can vary dramatically depending on environmental conditions within and across seasons, making them useful for studying the effects of feeding regime on various facets of reproductive fitness. In this study, there was a significant trend/difference in development and morphology for males and females as a result of juvenile feeding treatment, however, its effect on the fitness components measured for males was much greater than on those measured for females. Food-limited males were less likely to find a female during field enclosure experiments and smaller males were slower at finding a female in field-based experiments, providing some of the first empirical evidence of a large male size advantage for scrambling males. Only adult food limitation affected female fecundity, and the ability of a female to chemically attract males was also most notably affected by adult feeding regime (although juvenile food limitation did play a role). Furthermore, the significant difference/trend in all male traits and the lack of difference in male trait ratios between treatments suggests a proportional distribution of resources and, therefore, no trait conservation by food-limited males. This study provides evidence that males and females are under different selective pressures with respect to resource acquisition and is also one of very few to show an effect of juvenile

  3. PMRD: a curated database for genes and mutants involved in plant male reproduction

    PubMed Central

    2012-01-01

    Background Male reproduction is an essential biological event in the plant life cycle separating the diploid sporophyte and haploid gametophyte generations, which involves expression of approximately 20,000 genes. The control of male reproduction is also of economic importance for plant breeding and hybrid seed production. With the advent of forward and reverse genetics and genomic technologies, a large number of male reproduction-related genes have been identified. Thus it is extremely challenging for individual researchers to systematically collect, and continually update, all the available information on genes and mutants related to plant male reproduction. The aim of this study is to manually curate such gene and mutant information and provide a web-accessible resource to facilitate the effective study of plant male reproduction. Description Plant Male Reproduction Database (PMRD) is a comprehensive resource for browsing and retrieving knowledge on genes and mutants related to plant male reproduction. It is based upon literature and biological databases and includes 506 male sterile genes and 484 mutants with defects of male reproduction from a variety of plant species. Based on Gene Ontology (GO) annotations and literature, information relating to a further 3697 male reproduction related genes were systematically collected and included, and using in text curation, gene expression and phenotypic information were captured from the literature. PMRD provides a web interface which allows users to easily access the curated annotations and genomic information, including full names, symbols, locations, sequences, expression patterns, functions of genes, mutant phenotypes, male sterile categories, and corresponding publications. PMRD also provides mini tools to search and browse expression patterns of genes in microarray datasets, run BLAST searches, convert gene ID and generate gene networks. In addition, a Mediawiki engine and a forum have been integrated within the

  4. Scale-dependent feedbacks between patch size and plant reproduction in desert grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theoretical models suggest that scale-dependent feedbacks between plant reproductive success and plant patch size govern transitions from highly to sparsely vegetated states in drylands, yet there is scant empirical evidence for these mechanisms. Scale-dependent feedback models suggest that an optim...

  5. Maybe she's NOT the boss: male-female crosstalk during sexual plant reproduction.

    PubMed

    Vogler, Hannes; Martinez-Bernardini, Andrea; Grossniklaus, Ueli

    2016-01-01

    New insights into the molecular dialogue between male and female during sexual plant reproduction show that even plant sex does not work without clear communication.Please see related Research article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-0928-x. PMID:27159978

  6. Herbicide drift affects plant and arthropod communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field edges, old fields, and other semi-natural habitats in agricultural landscapes support diverse plant communities that help sustain pollinators, predators, and other beneficial arthropods. These plant and arthropod communities may be at persistent ecotoxicological risk from herbicides applied to...

  7. Plant Hormones: How They Affect Root Formation.

    ERIC Educational Resources Information Center

    Reinhard, Diana Hereda

    This science study aid, produced by the U.S. Department of Agriculture, includes a series of plant rooting activities for secondary science classes. The material in the pamphlet is written for students and includes background information on plant hormones, a vocabulary list, and five learning activities. Objectives, needed materials, and…

  8. Reproduction of Pseudocalanus newmani (Copepoda: Calanoida) is deleteriously affected by diatom blooms A field study

    NASA Astrophysics Data System (ADS)

    Halsband-Lenk, Claudia; Pierson, James J.; Leising, Andrew W.

    2005-11-01

    Copepod secondary production has traditionally been linked to the spring diatom bloom in temperate and high latitudes, but laboratory studies have recently challenged this view and have shown either reduced fecundity or viability of offspring when copepods were fed high concentrations of - mostly unialgal - diatoms. However, field evidence that diatoms affect copepod reproduction is still scarce. We analyzed the reproductive response of a common, small calanoid copepod of the boreal Pacific, Pseudocalanus newmani, to spring diatom blooms in Dabob Bay, a semi-enclosed fjord of Puget Sound, Washington, USA. Abundance patterns, egg production rates, egg hatching success, and naupliar viability of the egg-carrying copepod were examined between February and early May in the years 2002-2004. The population underwent strong variations in abundance during both years, with high abundance of all stages from February to mid-March, but dramatically decreasing individual numbers later in spring. A recovery to higher numbers occurred in July. While egg production rates were independent of chlorophyll concentrations, the reproductive success of P. newmani was negatively affected by certain phytoplankton bloom conditions. Hatching success and - more markedly - naupliar survival were reduced following peaks of Thalassiosira species that were producing anti-mitotic aldehydes, but were high during periods when phytoplankton blooms were more diverse or dominated by other prey taxa including diatoms. As a consequence, recruitment of the naupliar population was considerably affected by the Thalassiosira blooms. This study shows for the first time that the so-called diatom effect operates in nature when all prerequisites - (1) high concentration of aldehyde producers, (2) few prey alternatives, and (3) feeding of copepods on these algae - are given. However, the effect was transient in Dabob Bay and may be so in other pelagic ecosystems. It remains to discern the potential sources of

  9. Food availability affects onset of reproduction in a long-lived seabird

    PubMed Central

    Vincenzi, Simone; Hatch, Scott; Mangel, Marc; Kitaysky, Alexander

    2013-01-01

    Life-history theory predicts that suboptimal developmental conditions may lead to faster life histories (younger age at recruitment and higher reproductive investment), but experimental testing of this prediction is still scarce in long-lived species. We report the effects of an experimental manipulation of food availability during early development and at recruitment on the onset of reproduction and reproductive performance (productivity at first breeding) in a long-lived seabird, the black-legged kittiwake Rissa tridactyla, breeding on Middleton Island, Alaska. Birds were born and raised in nests with supplemented food (‘fed’) or unsupplemented control nests (‘unfed’), and later recruited into either fed or unfed nests. Fed chicks grew faster than unfed chicks, and males grew faster than females. Birds were more likely to reproduce at younger ages when recruiting into fed nests. Faster growth during development tended to increase age at recruitment in all individuals. Social rank of individuals also affected age at recruitment: B-chicks recruited earlier than A-chicks and singletons recruited later than A- and B-chicks. Productivity increased with the age at recruitment and growth rate as chick, but much of the variability remained unexplained. We conclude that results of this study at least partially support predictions of life-history theory: younger age at first breeding for kittiwakes that experienced suboptimal natal conditions, as well as greater productivity of early recruiting kittiwakes that grew in control nests compared with those that grew in food-supplemented nests. PMID:23576791

  10. Fishing top predators indirectly affects condition and reproduction in a reef-fish community.

    PubMed

    Walsh, S M; Hamilton, S L; Ruttenberg, B I; Donovan, M K; Sandin, S A

    2012-03-01

    To examine the indirect effects of fishing on energy allocation in non-target prey species, condition and reproductive potential were measured for five representative species (two-spot red snapper Lutjanus bohar, arc-eye hawkfish Paracirrhites arcatus, blackbar devil Plectroglyphidodon dickii, bicolour chromis Chromis margaritifer and whitecheek surgeonfish Acanthurus nigricans) from three reef-fish communities with different levels of fishing and predator abundance in the northern Line Islands, central Pacific Ocean. Predator abundance differed by five to seven-fold among islands, and despite no clear differences in prey abundance, differences in prey condition and reproductive potential among islands were found. Body condition (mean body mass adjusted for length) was consistently lower at sites with higher predator abundance for three of the four prey species. Mean liver mass (adjusted for total body mass), an indicator of energy reserves, was also lower at sites with higher predator abundance for three of the prey species and the predator. Trends in reproductive potential were less clear. Mean gonad mass (adjusted for total body mass) was high where predator abundance was high for only one of the three species in which it was measured. Evidence of consistently low prey body condition and energy reserves in a diverse suite of species at reefs with high predator abundance suggests that fishing may indirectly affect non-target prey-fish populations through changes in predation and predation risk. PMID:22380551

  11. Analgesic exposure in pregnant rats affects fetal germ cell development with inter-generational reproductive consequences

    PubMed Central

    Dean, Afshan; van den Driesche, Sander; Wang, Yili; McKinnell, Chris; Macpherson, Sheila; Eddie, Sharon L.; Kinnell, Hazel; Hurtado-Gonzalez, Pablo; Chambers, Tom J.; Stevenson, Kerrie; Wolfinger, Elke; Hrabalkova, Lenka; Calarrao, Ana; Bayne, Rosey AL; Hagen, Casper P.; Mitchell, Rod T.; Anderson, Richard A.; Sharpe, Richard M.

    2016-01-01

    Analgesics which affect prostaglandin (PG) pathways are used by most pregnant women. As germ cells (GC) undergo developmental and epigenetic changes in fetal life and are PG targets, we investigated if exposure of pregnant rats to analgesics (indomethacin or acetaminophen) affected GC development and reproductive function in resulting offspring (F1) or in the F2 generation. Exposure to either analgesic reduced F1 fetal GC number in both sexes and altered the tempo of fetal GC development sex-dependently, with delayed meiotic entry in oogonia but accelerated GC differentiation in males. These effects persisted in adult F1 females as reduced ovarian and litter size, whereas F1 males recovered normal GC numbers and fertility by adulthood. F2 offspring deriving from an analgesic-exposed F1 parent also exhibited sex-specific changes. F2 males exhibited normal reproductive development whereas F2 females had smaller ovaries and reduced follicle numbers during puberty/adulthood; as similar changes were found for F2 offspring of analgesic-exposed F1 fathers or mothers, we interpret this as potentially indicating an analgesic-induced change to GC in F1. Assuming our results are translatable to humans, they raise concerns that analgesic use in pregnancy could potentially affect fertility of resulting daughters and grand-daughters. PMID:26813099

  12. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    PubMed

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation. PMID:26361480

  13. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    PubMed Central

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W.; Ryu, Choong-Min

    2015-01-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation. PMID:26361480

  14. Osmolyte cooperation affects turgor dynamics in plants.

    PubMed

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-01-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes. PMID:27445173

  15. Osmolyte cooperation affects turgor dynamics in plants

    PubMed Central

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-01-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes. PMID:27445173

  16. Osmolyte cooperation affects turgor dynamics in plants

    NASA Astrophysics Data System (ADS)

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-07-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes.

  17. Parental age affects somatic mutation rates in the progeny of flowering plants.

    PubMed

    Singh, Amit Kumar; Bashir, Tufail; Sailer, Christian; Gurumoorthy, Viswanathan; Ramakrishnan, Anantha Maharasi; Dhanapal, Shanmuhapreya; Grossniklaus, Ueli; Baskar, Ramamurthy

    2015-05-01

    In humans, it is well known that the parental reproductive age has a strong influence on mutations transmitted to their progeny. Meiotic nondisjunction is known to increase in older mothers, and base substitutions tend to go up with paternal reproductive age. Hence, it is clear that the germinal mutation rates are a function of both maternal and paternal ages in humans. In contrast, it is unknown whether the parental reproductive age has an effect on somatic mutation rates in the progeny, because these are rare and difficult to detect. To address this question, we took advantage of the plant model system Arabidopsis (Arabidopsis thaliana), where mutation detector lines allow for an easy quantitation of somatic mutations, to test the effect of parental age on somatic mutation rates in the progeny. Although we found no significant effect of parental age on base substitutions, we found that frameshift mutations and transposition events increased in the progeny of older parents, an effect that is stronger through the maternal line. In contrast, intrachromosomal recombination events in the progeny decrease with the age of the parents in a parent-of-origin-dependent manner. Our results clearly show that parental reproductive age affects somatic mutation rates in the progeny and, thus, that some form of age-dependent information, which affects the frequency of double-strand breaks and possibly other processes involved in maintaining genome integrity, is transmitted through the gametes. PMID:25810093

  18. Parental Age Affects Somatic Mutation Rates in the Progeny of Flowering Plants1

    PubMed Central

    Singh, Amit Kumar; Bashir, Tufail; Sailer, Christian; Gurumoorthy, Viswanathan; Ramakrishnan, Anantha Maharasi; Dhanapal, Shanmuhapreya; Grossniklaus, Ueli; Baskar, Ramamurthy

    2015-01-01

    In humans, it is well known that the parental reproductive age has a strong influence on mutations transmitted to their progeny. Meiotic nondisjunction is known to increase in older mothers, and base substitutions tend to go up with paternal reproductive age. Hence, it is clear that the germinal mutation rates are a function of both maternal and paternal ages in humans. In contrast, it is unknown whether the parental reproductive age has an effect on somatic mutation rates in the progeny, because these are rare and difficult to detect. To address this question, we took advantage of the plant model system Arabidopsis (Arabidopsis thaliana), where mutation detector lines allow for an easy quantitation of somatic mutations, to test the effect of parental age on somatic mutation rates in the progeny. Although we found no significant effect of parental age on base substitutions, we found that frameshift mutations and transposition events increased in the progeny of older parents, an effect that is stronger through the maternal line. In contrast, intrachromosomal recombination events in the progeny decrease with the age of the parents in a parent-of-origin-dependent manner. Our results clearly show that parental reproductive age affects somatic mutation rates in the progeny and, thus, that some form of age-dependent information, which affects the frequency of double-strand breaks and possibly other processes involved in maintaining genome integrity, is transmitted through the gametes. PMID:25810093

  19. PFRU, a single dominant locus regulates the balance between sexual and asexual plant reproduction in cultivated strawberry.

    PubMed

    Gaston, Amèlia; Perrotte, Justine; Lerceteau-Köhler, Estelle; Rousseau-Gueutin, Mathieu; Petit, Aurélie; Hernould, Michel; Rothan, Christophe; Denoyes, Béatrice

    2013-04-01

    Strawberry (Fragaria sp.) stands as an interesting model for studying flowering behaviour and its relationship with asexual plant reproduction in polycarpic perennial plants. Strawberry produces both inflorescences and stolons (also called runners), which are lateral stems growing at the soil surface and producing new clone plants. In this study, the flowering and runnering behaviour of two cultivated octoploid strawberry (Fragaria × ananassa Duch., 2n = 8× = 56) genotypes, a seasonal flowering genotype CF1116 and a perpetual flowering genotype Capitola, were studied along the growing season. The genetic bases of the perpetual flowering and runnering traits were investigated further using a pseudo full-sibling F1 population issued from a cross between these two genotypes. The results showed that a single major quantitative trait locus (QTL) named FaPFRU controlled both traits in the cultivated octoploid strawberry. This locus was not orthologous to the loci affecting perpetual flowering (SFL) and runnering (R) in Fragaria vesca, therefore suggesting different genetic control of perpetual flowering and runnering in the diploid and octoploid Fragaria spp. Furthermore, the FaPFRU QTL displayed opposite effects on flowering (positive effect) and on runnering (negative effect), indicating that both traits share common physiological control. These results suggest that this locus plays a major role in strawberry plant fitness by controlling the balance between sexual and asexual plant reproduction. PMID:23554259

  20. Evidence that elevated water temperature affects the reproductive physiology of the European bullhead Cottus gobio.

    PubMed

    Dorts, Jennifer; Grenouillet, Gaël; Douxfils, Jessica; Mandiki, Syaghalirwa N M; Milla, Sylvain; Silvestre, Frédéric; Kestemont, Patrick

    2012-04-01

    Climate change is predicted to increase the average water temperature and alter the ecology and physiology of several organisms including fish species. To examine the effects of increased water temperature on freshwater fish reproduction, adult European bullhead Cottus gobio of both genders were maintained under three temperature regimes (T1: 6-10, T2: 10-14 and T3: 14-18°C) and assessed for gonad development (gonadosomatic index-GSI and gonad histology), sex steroids (testosterone-T, 17β-estradiol-E2 and 11-ketotestosterone-11-KT) and vitellogenin (alkali-labile phosphoprotein phosphorus-ALP) dynamics in December, January, February and March. The results indicate that a 8°C rise in water temperature (T3) deeply disrupted the gonadal maturation in both genders. This observation was associated with the absence of GSI peak from January to March, and low levels of plasma sex steroids compared with T1-exposed fish. Nevertheless, exposure to an increasing temperature of 4°C (T2) appeared to accelerate oogenesis with an early peak value in GSI and level of plasma T recorded in January relative to T1-exposed females. In males, the low GSI, reduced level of plasma 11-KT and the absence of GSI increase from January to March support the deleterious effects of increasing water temperature on spermatogenesis. The findings of the present study suggest that exposure to elevated temperatures within the context of climate warming might affect the reproductive success of C. gobio. Specifically, a 4°C rise in water temperature affects gametogenesis by advancing the spawning, and a complete reproductive failure is observed at an elevated temperature of 8°C. PMID:21638008

  1. The effect of Bt-transgene introgression on plant growth and reproduction in wild Brassica juncea.

    PubMed

    Liu, Yong-Bo; Darmency, Henry; Stewart, C Neal; Wei, Wei; Tang, Zhi-Xi; Ma, Ke-Ping

    2015-06-01

    This study aims to investigate the relative plant growth and reproduction of insect-resistant and susceptible plants following the introgression of an insect-resistance Bt-transgene from Brassica napus, oilseed rape, to wild Brassica juncea. The second backcrossed generation (BC2) from a single backcross family was grown in pure and mixed stands of Bt-transgenic and non-transgenic siblings under two insect treatments. Various proportions of Bt-transgenic plants were employed in mixed stands to study the interaction between resistant and susceptible plants. In the pure stands, Bt-transgenic BC2 plants performed better than non-transgenic plants with or without insect treatments. In mixed stands, Bt-transgenic BC2 plants produced fewer seeds than their non-Bt counterparts at low proportions of Bt-transgenic BC2 plants in the absence of insects. Reproductive allocation of non-transgenic plants marginally increased with increasing proportions of Bt-transgenic plants under herbivore pressure, which resulted in increased total biomass and seed production per stand. The results showed that the growth of non-transgenic plants was protected by Bt-transgenic plants under herbivore pressure. The Bt-transgene might not be advantageous in mixed stands of backcrossed hybrids; thus transgene introgression would not be facilitated when herbivorous insects are not present. However, a relatively large initial population of Bt-transgenic plants might result in transgene persistence when target herbivores are present. PMID:25487040

  2. Corticosterone metabolism by chicken follicle cells does not affect ovarian reproductive hormone synthesis in vitro

    PubMed Central

    Rettenbacher, Sophie; Henriksen, Rie; Groothuids, Ton G.; Lepschy, Michael

    2013-01-01

    Glucocorticoids affect reproductive hormone production in many species. In chickens, elevated plasma corticosterone down-regulates testosterone and progesterone concentrations in plasma, but also in egg yolk. This suppression could be mediated via the hypothalamic-pituitary system but also via local inhibition of gonadal activity by glucocorticoids. As the latter has not been tested in birds yet, we tested if corticosterone directly inhibits ovarian steroid synthesis under in vitro conditions. We hypothesized that degradation of corticosterone by follicular cells impairs their ability to synthesize reproductive hormones due to either inhibition of enzymes or competition for common co-factors. Therefore, we first established whether follicles degrade corticosterone. Follicular tissue was harvested from freshly euthanized laying hens and incubated with radiolabelled corticosterone. Radioactive metabolites were visualized and quantified by autoradiography. Follicles converted corticosterone in a time-dependent manner into metabolites with a higher polarity than corticosterone. The predominant metabolite co-eluted with 20β-dihydrocorticosterone. Other chicken tissues mostly formed the same metabolite when incubated with corticosterone. In a second experiment, follicles were incubated with either progesterone or dehydroepiandrosterone. Corticosterone was added in increasing dosages up to 1000 ng per ml medium. Corticosterone did not inhibit the conversion of progesterone and dehydroepiandrosterone into a number of different metabolites, including 17α-hydroxyprogesterone, androstenedione and testosterone. In conclusion, avian tissues degrade corticosterone mostly to 20β-dihydrocorticosterone and even high corticosterone dosages do not affect follicular hormone production under in vitro conditions. PMID:23333751

  3. Agroforestry planting design affects loblolly pine growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of plantation design on resource utilization has not been adequately investigated in agroforestry plantations. An experiment was conducted near Booneville, AR on a silt loam soil with a fragipan. Loblolly pine trees were planted in 1994 in an east-west row orientation in three designs: ...

  4. Mitochondrial gamma carbonic anhydrases are required for complex I assembly and plant reproductive development.

    PubMed

    Fromm, Steffanie; Braun, Hans-Peter; Peterhansel, Christoph

    2016-07-01

    Complex I of the mitochondrial electron transport chain (mETC) in plants contains an extra domain that is made up from proteins homologous to prokaryotic gamma-carbonic anhydrases (γCA). This domain has been suggested to participate in complex I assembly or to support transport of mitochondrial CO2 to the chloroplast. Here, we generated mutants lacking CA1 and CA2 - two out of three CA proteins in Arabidopsis thaliana. Double mutants were characterized at the developmental and physiological levels. Furthermore, the composition and activity of the mETC were determined, and mutated CA versions were used for complementation assays. Embryo development of double mutants was strongly delayed and seed development stopped before maturation. Mutant plants could only be rescued on sucrose media, showed severe stress symptoms and never produced viable seeds. By contrast, callus cultures were only slightly affected in growth. Complex I was undetectable in the double mutants, but complex II and complex IV were upregulated concomitant with increased oxygen consumption in mitochondrial respiration. Ectopic expression of inactive CA variants was sufficient to complement the mutant phenotype. Data indicate that CA proteins are structurally required for complex I assembly and that reproductive development is dependent on the presence of complex I. PMID:26889912

  5. Biomarker responses and reproductive toxicity of the effluent from a Chinese large sewage treatment plant in Japanese medaka (Oryzias latipes).

    PubMed

    Ma, Taowu; Wan, Xiaoqiong; Huang, Qinghui; Wang, Zijian; Liu, Jiankang

    2005-04-01

    The present study was conducted to assess the potential toxicity of the effluent from a large sewage treatment plant (GBD-STP) in Beijing. Japanese medakas (Oryzias latipes) at reproduction active period were exposed to a serial of graded concentrations of the effluent or 100 ng l-1 of 17-alpha-ethinylestradiol (EE2, positive control). Growth, gonadosomatic index (GSI), hepatosomatic index (HSI), reproductive success, induction potency of vitellogenin (VTG) in male fish and that of 7-ethoxyresorufin-o-deethylase activity (EROD) in male fish liver were used as test endpoints. The growth suppression of fish was observed in a dose-dependent manner, resulting in significant differences in both body length and body weight of medaka above 5% effluent. This effluent can inhibit the growth of gonad of medakas and are more sensitive to male than to female. At exposure concentration of 40% and higher, there was an unexpected decrease of HSI values, which may be resulted from sub-lethal toxicity of effluent to fish liver. VTG of plasma in males were induced in all exposure concentration levels, but not in a dose-dependent manner. The concentration of 5% effluent would be the lowest observed adverse effect level (LOAEL) affecting reproductive success when examining fertile individuals, fecundity and fertilization rate. The overt CYP1A response and higher reproductive toxicity may be indicative of low process efficiency of this STP. PMID:15722100

  6. Physical stress modifies top-down and bottom-up forcing on plant growth and reproduction in a coastal ecosystem.

    PubMed

    Daleo, Pedro; Alberti, Juan; Bruschetti, Carlos Martin; Pascual, Jesos; Iribarne, Oscar; Silliman, Brian R

    2015-08-01

    Bottom-up and top-down effects act together to exert strong control over plant growth and reproduction, but how physical stress modifies those interactive forces remains unclear. Even though empirical evidence is scarce, theory predicts that the importance of both top-down- and bottom-up forces may decrease as physical stress increases. Here, we experimentally evaluate in the field the separate and interactive effect of salinity, nutrient availability, and crab herbivory on plant above- and belowground biomass, as well as on sexual and clonal reproduction in the salt marsh plant Spartina densiflora. Results show that the outcome of the interaction between nutrient availability and herbivory is highly context dependent, not only varying with the abiotic context (i.e., with or without increased salinity stress), but also with the dependent variable considered. Contrary to theoretical predictions, our results show that, consistently across different measured variables, salinity stress did not cancel bottom-up (i.e., nutrients) or top-down (i.e., consumers) control, but has additive effects. Our results support emerging theory by highlighting that, under many conditions, physical stress can act additively with, or even stimulate, consumer control, especially in cases where the physical stress is only experienced by basal levels of the trophic chain. Abiotic stress, as well as bottom-up and top-down factors, can affect salt marsh structure and function not only by affecting biomass production but also by having other indirect effects, such as changing patterns in plant biomass allocation and reproduction. PMID:26405740

  7. Is there a missing link? Effects of root herbivory on plant-pollinator interactions and reproductive output in a monocarpic species.

    PubMed

    Ghyselen, C; Bonte, D; Brys, R

    2016-01-01

    Herbivores can have a major influence on plant fitness. The direct impact of herbivory on plant reproductive output has long been studied, and recently also indirect effects of herbivory on plant traits and pollinator attraction have received increasing attention. However, the link between these direct and indirect effects has seldom been studied. In this study, we investigated effects of root herbivory on plant and floral traits, pollination success and reproductive outcome in the monocarpic perennial Cynoglossum officinale. We exposed 119 C. officinale plants to a range of root herbivore damage by its specialist herbivore Mogulones cruciger. We assessed the effect of herbivory on several plant traits, pollinator foraging behaviour and reproductive output, and to elucidate the link between these last two we also quantified pollen deposition and pollen tube growth and applied a pollination experiment to test whether seed set was pollen-limited. Larval root herbivory induced significant changes in plant traits and had a negative impact on pollinator visitation. Infested plants were reduced in size, had fewer flowers and received fewer pollinator visits at plant and flower level than non-infested plants. Also, seed set was negatively affected by root herbivory, but this could not be attributed to pollen limitation since neither stigmatic pollen loads and pollen tube growth nor the results of the hand-pollination experiment differed between infested and non-infested plants. Our observations demonstrate that although herbivory may induce significant changes in flowering behaviour and resulting plant-pollinator interactions, it does not necessarily translate into higher rates of pollen limitation. The observed reductions in reproductive output following infection can mainly be attributed to higher resource limitation compared to non-infested plants. PMID:25731922

  8. Reproduction during spaceflight by plants in the family Brassicaceae

    NASA Technical Reports Server (NTRS)

    Musgrave, M. E.; Kuang, A.

    2001-01-01

    Researchers report on studies of reproduction in Arabidopsis thaliana in space during during the Chromex-03 on STS-54, Chromex-04 on STS-51, and Chromex-05 on STS-68 missions. The obstacles to seed formation were related to carbon dioxide levels. Other experiments examined in flight pollination and seed production in Brassica rapa during parabolic flight, a 4-1/2 month stay on Mir, and on STS-87. During the Mir experiment, Brassica seeds were harvested from seeds sown in flight. The second generation seeds grew to produce new seeds that contained more starch and less protein and lipid when compared to ground control seeds.

  9. Low investment in sexual reproduction threatens plants adapted to phosphorus limitation

    NASA Astrophysics Data System (ADS)

    Fujita, Yuki; Venterink, Harry Olde; van Bodegom, Peter M.; Douma, Jacob C.; Heil, Gerrit W.; Hölzel, Norbert; Jabłońska, Ewa; Kotowski, Wiktor; Okruszko, Tomasz; Pawlikowski, Paweł; de Ruiter, Peter C.; Wassen, Martin J.

    2014-01-01

    Plant species diversity in Eurasian wetlands and grasslands depends not only on productivity but also on the relative availability of nutrients, particularly of nitrogen and phosphorus. Here we show that the impacts of nitrogen:phosphorus stoichiometry on plant species richness can be explained by selected plant life-history traits, notably by plant investments in growth versus reproduction. In 599 Eurasian sites with herbaceous vegetation we examined the relationship between the local nutrient conditions and community-mean life-history traits. We found that compared with plants in nitrogen-limited communities, plants in phosphorus-limited communities invest little in sexual reproduction (for example, less investment in seed, shorter flowering period, longer lifespan) and have conservative leaf economy traits (that is, a low specific leaf area and a high leaf dry-matter content). Endangered species were more frequent in phosphorus-limited ecosystems and they too invested little in sexual reproduction. The results provide new insight into how plant adaptations to nutrient conditions can drive the distribution of plant species in natural ecosystems and can account for the vulnerability of endangered species.

  10. Low investment in sexual reproduction threatens plants adapted to phosphorus limitation.

    PubMed

    Fujita, Yuki; Venterink, Harry Olde; van Bodegom, Peter M; Douma, Jacob C; Heil, Gerrit W; Hölzel, Norbert; Jabłońska, Ewa; Kotowski, Wiktor; Okruszko, Tomasz; Pawlikowski, Paweł; de Ruiter, Peter C; Wassen, Martin J

    2014-01-01

    Plant species diversity in Eurasian wetlands and grasslands depends not only on productivity but also on the relative availability of nutrients, particularly of nitrogen and phosphorus. Here we show that the impacts of nitrogen:phosphorus stoichiometry on plant species richness can be explained by selected plant life-history traits, notably by plant investments in growth versus reproduction. In 599 Eurasian sites with herbaceous vegetation we examined the relationship between the local nutrient conditions and community-mean life-history traits. We found that compared with plants in nitrogen-limited communities, plants in phosphorus-limited communities invest little in sexual reproduction (for example, less investment in seed, shorter flowering period, longer lifespan) and have conservative leaf economy traits (that is, a low specific leaf area and a high leaf dry-matter content). Endangered species were more frequent in phosphorus-limited ecosystems and they too invested little in sexual reproduction. The results provide new insight into how plant adaptations to nutrient conditions can drive the distribution of plant species in natural ecosystems and can account for the vulnerability of endangered species. PMID:24240278

  11. Do transgenic plants affect rhizobacteria populations?

    PubMed Central

    Filion, Martin

    2008-01-01

    Summary Plant genetic manipulation has led to the development of genetically modified plants (GMPs) expressing various traits. Since their first commercial use in 1996, GMPs have been increasingly used, reaching a global cultivating production area of 114.3 million hectares in 2007. The rapid development of agricultural biotechnology and release of GMPs have provided many agronomic and economic benefits, but has also raised concerns over the potential impact these plants might have on the environment. Among these environmental concerns, the unintentional impact that GMPs might have on soil‐associated microbes, especially rhizosphere‐inhabiting bacteria or rhizobacteria, represents one of the least studied and understood areas. As rhizobacteria are responsible for numerous key functions including nutrient cycling and decomposition, they have been defined as good indicator organisms to assess the general impact that GMPs might have on the soil environment. This minireview summarizes the results of various experiments that have been conducted to date on the impact of GMPs on rhizobacteria. Both biological and technical parameters are discussed and an attempt is made to determine if specific rhizobacterial responses exist for the different categories of GMPs developed to date. PMID:21261867

  12. Comparative studies on plant range size: Linking reproductive and regenerative traits in two Ipomoea species

    NASA Astrophysics Data System (ADS)

    Astegiano, Julia; Funes, Guillermo; Galetto, Leonardo

    2010-09-01

    Reproductive and regenerative traits associated with colonization and persistence ability may determine plant range size. However, few comparative studies on plant distribution have assessed these traits simultaneously. Pollinator richness and frequency of visits, autonomous self-pollination ability, reproductive output (i.e., reproductive traits), seed bank strategy and seedling density (i.e., regenerative traits) were compared between the narrowly distributed Ipomoea rubriflora O'Donnell (Convolvulaceae) and its widespread congener Ipomoea purpurea (L.) Roth. The narrowly distributed species showed higher ecological specialization to pollinators and lower autonomous self-pollination ability. Frequency of visits, natural seed/ovule ratio and fruit set, and total fruit production did not differ between species. However, the number of seeds produced per fruit was lower in the narrowly distributed species, translating into lower total seed production per plant. Indeed, I. rubriflora formed smaller transient and persistent seed banks and showed lower seedling density than the widespread I. purpurea. These reproductive and regenerative trait results suggest that the narrowly distributed species may have lower colonization and persistence ability than its widespread congener. They further suggest that the negative effects of lower fecundity in the narrowly distributed species might persist in time through the long-lasting effects of total seed production on seed bank size, reducing the species' ability to buffered environmental stochasticity. However, other regenerative traits, such as seed size, and processes such as pre- and post-dispersal seed predation, might modulate the effects of plant fecundity on plant colonization and persistence ability and thus range size.

  13. Effects of thermal power plant effluents on formation and senescence of reproductive parts of Anagallis arvensis L

    SciTech Connect

    Iqbal, M.; Khan, F.A.; Saquib, M.; Ahmad, Z.; Ghouse, A.K.M. )

    1989-04-01

    Oxides of sulfur, nitrogen and carbon and particulates are the major air pollutants emitted in huge amounts by the Thermal Power Plant Complex of Kasimpur (Aligarh, UP, India) running on 3192 MT of coal/day. These effluents significantly affect reproductive phase of Anagallis arvensis L. Samples of 10 plants each were randomly collected at monthly intervals at seedling to mature stage from 0.5, 2, 6, 12 and 20 km leeward from the power plant complex. Bud formation and flowering were delayed in the population thriving at 0.5 km from the pollution source. As a 2 month old stage, 60% of the population showed a decline in bud formation in the vicinity of the source compared to a heavy bud emergence in the whole population thriving 20 km away from it. Bud formation, flowering fruit set and seed set showed a correlation with multiple growth factors viz productivity, shoot length and distance from the source.

  14. Disruption of amylase genes by RNA interference affects reproduction in the Pacific oyster Crassostrea gigas.

    PubMed

    Huvet, Arnaud; Béguel, Jean-Philippe; Cavaleiro, Nathalia Pereira; Thomas, Yoann; Quillien, Virgile; Boudry, Pierre; Alunno-Bruscia, Marianne; Fabioux, Caroline

    2015-06-01

    Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: -50.7% and -59% mRNA A, and -71.9% and -70.6% mRNA B in 15 and 75 µg dsRNA-injected oysters, respectively, relative to controls. Interestingly, reproductive knock-down phenotypes were observed for both sexes at 48 days post-injection, with a significant reduction of the gonad area (-22.5% relative to controls) and germ cell under-proliferation revealed by histology. In response to the higher dose of dsRNA, we also observed reductions in amylase activity (-53%) and absorption efficiency (-5%). Based on these data, dynamic energy budget modeling showed that the limitation of energy intake by feeding that was induced by injection of amylase dsRNA was insufficient to affect gonadic development at the level observed in the present study. This finding suggests that other driving mechanisms, such as endogenous hormonal modulation, might significantly change energy allocation to reproduction, and increase the maintenance rate in oysters in response to dsRNA injection. PMID:25883379

  15. Metabolic stressors and signals differentially affect energy allocation between reproduction and immune function.

    PubMed

    Carlton, Elizabeth D; Cooper, Candace L; Demas, Gregory E

    2014-11-01

    Most free-living animals have finite energy stores that they must allocate to different physiological and behavioral processes. In times of energetic stress, trade-offs in energy allocation among these processes may occur. The manifestation of trade-offs may depend on the source (e.g., glucose, lipids) and severity of energy limitation. In this study, we investigated energetic trade-offs between the reproductive and immune systems by experimentally limiting energy availability to female Siberian hamsters (Phodopus sungorus) with 2-deoxy-d-glucose, a compound that disrupts cellular utilization of glucose. We observed how glucoprivation at two levels of severity affected allocation to reproduction and immunity. Additionally, we treated a subset of these hamsters with leptin, an adipose hormone that provides a direct signal of available fat stores, in order to determine how increasing this signal of fat stores influences glucoprivation-induced trade-offs. We observed trade-offs between the reproductive and immune systems and that these trade-offs depended on the severity of energy limitation and exogenous leptin signaling. The majority of the animals experiencing mild glucoprivation entered anestrus, whereas leptin treatment restored estrous cycling in these animals. Surprisingly, virtually all animals experiencing more severe glucoprivation maintained normal estrous cycling throughout the experiment; however, exogenous leptin resulted in lower antibody production in this group. These data suggest that variation in these trade-offs may be mediated by shifts between glucose and fatty acid utilization. Collectively, the results of the present study highlight the context-dependent nature of these trade-offs, as trade-offs induced by the same metabolic stressor can manifest differently depending on its intensity. PMID:25125082

  16. Altered reproductive behaviours in male mosquitofish living downstream from a sewage treatment plant.

    PubMed

    Saaristo, Minna; Myers, Jackie; Jacques-Hamilton, Rowan; Allinson, Mayumi; Yamamoto, Atsushi; Allinson, Graeme; Pettigrove, Vincent; Wong, Bob B M

    2014-04-01

    Freshwater environments are common repositories for the discharge of large volumes of domestic and industrial waste, particularly through wastewater effluent. One common group of chemical pollutants present in wastewater are endocrine disrupting chemicals (EDCs), which can induce morphological and behavioural changes in aquatic organisms. The aim of this study was to compare the reproductive behaviour and morphology of a freshwater fish, the mosquitofish (Gambusia holbrooki), collected from two sites (wastewater treatment plant (WWTP) and a putative pristine site). The mosquitofish is a sexually dimorphic livebearer with a coercive mating system. Males inseminate females using their modified anal fin as an intromittent organ. Despite this, females are able to exert some control over the success of male mating attempts by selectively associating with, or avoiding, certain males over others. Using standard laboratory assays of reproductive behaviour, we found that mosquitofish males living in close proximity to WWTP showed increased mating activity compared to those inhabiting a pristine site. More specifically, during behavioural trials in which males were allowed to interact with females separated by a transparent divider, we found that WWTP-males spent more time associating with females. Concordant with this, when males and females were subsequently allowed to interact freely, WWTP-males also spent more time chasing and orienting towards the females. As a result, females from both sites showed more interest towards the WWTP-site males. Male anal fin morphology, however, did not differ between sites. Our study illustrates that lifetime exposure to WWTP-effluents can greatly affect male behaviour. The results underscore the importance of behaviour as a potential tool for investigating unknown contaminants in the environment. PMID:24569133

  17. The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions

    PubMed Central

    Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A.

    2014-01-01

    The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

  18. Direct effects of energy-related air pollutants on plant sexual reproduction. Final report, February 1, 1979--January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  19. Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination.

    PubMed

    Warner, Daniel A; Lovern, Matthew B; Shine, Richard

    2007-03-22

    Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of 'environmental sex determination'. PMID:17251109

  20. Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination

    PubMed Central

    Warner, Daniel A; Lovern, Matthew B; Shine, Richard

    2007-01-01

    Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of ‘environmental sex determination’. PMID:17251109

  1. Factors affecting reproductive success in three entomophilous orchid species in Hungary.

    PubMed

    Vojtkó, Anna E; Sonkoly, Judit; Lukács, Balázs András; Molnár V, Attila

    2015-06-01

    The reproductive success of orchids is traditionally estimated by determining the fruit-set of individuals. Here, we investigated both the fruit and the seed production of three orchid species and the factors that may affect individual fruit-set, like pollination strategy, individual traits or the annual amount of precipitation. The species [Dactylorhiza sambucina (L.) Soó, Dactylorhiza majalis (Rchb.) P. F. Hunt & Summerhayes and Platanthera bifolia (L.) L. C. M. Richard] were studied in three consecutive years (2010-2012) in the Bükk Mountains, Hungary. All three species were proved to be non-autogamous by a bagging experiment. Data analyses showed significant differences between seed numbers but not between fruit-sets of species. There was no statistical difference in individual reproductive success between wet and dry years, however, the effect of the annual amount of precipitation is significant on the population level. Comparison of published fruit-set data revealed accordance with our results in P. bifolia, but not in D. sambucina and D. majalis. We assume that the surprisingly high fruit-set values of the two Dactylorhiza species may be due to the fact that the pollination crisis reported from Western European countries is not an actual problem in the Bükk Mountains, Hungary. PMID:26081278

  2. Spring phenology does not affect timing of reproduction in the great tit (Parus major).

    PubMed

    Schaper, Sonja V; Rueda, Carolina; Sharp, Peter J; Dawson, Alistair; Visser, Marcel E

    2011-11-01

    Many seasonal breeders adjust the timing of reproduction in response to year-to-year variations in supplementary environmental cues, amongst which ambient temperature is thought to be most influential. However, it is possible that for species such as the great tit (Parus major L.), phenological cues from sprouting vegetation and the consequent abundance of invertebrate prey, although dependent on temperature, may provide supplementary environmental cues per se. This hypothesis was investigated in breeding pairs of great tits kept in outdoor aviaries. In spring, experimental pairs were provided with access to leafing birch branches and caterpillars as a visual food cue, while control pairs were provided with non-leafing branches. Observations were made on the onset of laying and on concentrations of plasma luteinizing hormone (LH) at regular intervals to monitor changes in reproductive function. The onset of egg laying was not advanced by the presence of leafing branches and caterpillars. LH concentrations increased during the course of the study, but phenological cues did not affect plasma LH levels in females and males. Early spring vegetation, such as the leafing of birch branches, and the appearance of caterpillar prey do not appear to play a significant role in fine-tuning the onset of egg laying in great tits. PMID:21993796

  3. Second-Hand Eating? Maternal perception of the food environment affects reproductive investment in mice

    PubMed Central

    Schwartz, Tonia S.; Gainer, Renee; Dohm, Erik D.; Johnson, Maria S.; Wyss, J. Michael; Allison, David B.

    2015-01-01

    Objective Little information exists on how perception of the food (or ‘energetic’) environment affects body composition and reproductive investment. We test the hypothesis that female mice, who are themselves consuming standard chow diets, but who are exposed to conspecifics eating a rich “cafeteria diet”, will exhibit altered weight gain and reproductive investment. Design and Methods Female C57BL/6 mice were raised on a cafeteria diet. At maturity, subjects were switched to a standard chow diet and their cage-mate was assigned to consume either a cafeteria diet (treatment, n=20), or standard chow (control, n=20). Subjects were mated, and pups raised to weaning. Subjects and pups were analyzed for body composition. Results Treatment had no discernable effect on dam body weight or composition, but caused pups to have lower body weight (p=0.036), and less fat mass (p=0.041). We found a nearly significant treatment effect on ‘time to successful reproduction’ (avg. 55 vs. 44 days) likely due to increased failed first pregnancies (14/19 versus 8/19, p=0.099). Conclusions These data indicate that perceived food environment (independent of the diet actually consumed) can produce small pups with less body fat, and possibly induce difficulties in pregnancy for dams. Replication and mechanistic studies should follow. PMID:25864567

  4. Reproduction of the Medicinal Plant Pelargonium sidoides via Somatic Embryogenesis.

    PubMed

    Duchow, Stefanie; Blaschek, Wolfgang; Classen, Birgit

    2015-08-01

    The medicinal plant Pelargonium sidoides DC. (Geraniaceae) was traditionally used for the treatment of the common cold and cough in South Africa. Today an aequous-ethanolic root extract from this plant is approved for the treatment of acute bronchitis and is globally marketed also as an immunostimulant. The increasing demand of the plant material for the industrial production indicates the need of new effective methods for the propagation of P. sidoides. Here we report somatic embryogenesis and in vitro plantlet regeneration from somatic cells of inflorescence shoots and petioles of P. sidoides. A one-week cultivation of explants in media containing different concentrations of thidiazuron (1, 2.2, 3, and 4 mg/L) followed by a cultivation period without phytohormones resulted in the induction of somatic embryos within 2-4 weeks. After 2-4 months, the embryos generated roots and could be transferred into a greenhouse, where flower formation took place and the development of seeds occurred with high germination rates. The root umckalin concentration, determined by high-performance thin-layer chromatography, was comparable to that of seed-cultivated plants (100 ± 6 vs. 113 ± 10 µg umckalin/g dried roots). For the first time, direct somatic embryogenesis has been established as an appropriate cultivation method for P. sidoides plants used as raw material in the pharmaceutical industry. Moreover, genetically identical plants (chemical races) can be easily generated by this procedure. PMID:26287694

  5. Chilling and chipping influence plant growth and reproduction of star-of-Bethlehem (Ornithogalum umbellatum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse studies were conducted on two southern Illinois star-of-Bethlehem biotypes to determine the influence of chilling and bulb chipping on plant growth and reproduction. Chilling was not required for leaf emergence of dormant bulbs, but an increase to 10 weeks of chilling proportionally delay...

  6. Ontogenetic shifts in plant interactions vary with environmental severity and affect population structure.

    PubMed

    le Roux, Peter C; Shaw, Justine D; Chown, Steven L

    2013-10-01

    Environmental conditions and plant size may both alter the outcome of inter-specific plant-plant interactions, with seedlings generally facilitated more strongly than larger individuals in stressful habitats. However, the combined impact of plant size and environmental severity on interactions is poorly understood. Here, we tested explicitly for the first time the hypothesis that ontogenetic shifts in interactions are delayed under increasingly severe conditions by examining the interaction between a grass, Agrostis magellanica, and a cushion plant, Azorella selago, along two severity gradients. The impact of A. selago on A. magellanica abundance, but not reproductive effort, was related to A. magellanica size, with a trend for delayed shifts towards more negative interactions under greater environmental severity. Intermediate-sized individuals were most strongly facilitated, leading to differences in the size-class distribution of A. magellanica on the soil and on A. selago. The A. magellanica size-class distribution was more strongly affected by A. selago than by environmental severity, demonstrating that the plant-plant interaction impacts A. magellanica population structure more strongly than habitat conditions. As ontogenetic shifts in plant-plant interactions cannot be assumed to be constant across severity gradients and may impact species population structure, studies examining the outcome of interactions need to consider the potential for size- or age-related variation in competition and facilitation. PMID:23738758

  7. Allocation, stress tolerance and carbon transport in plants: how does phloem physiology affect plant ecology?

    PubMed

    Savage, Jessica A; Clearwater, Michael J; Haines, Dustin F; Klein, Tamir; Mencuccini, Maurizio; Sevanto, Sanna; Turgeon, Robert; Zhang, Cankui

    2016-04-01

    Despite the crucial role of carbon transport in whole plant physiology and its impact on plant-environment interactions and ecosystem function, relatively little research has tried to examine how phloem physiology impacts plant ecology. In this review, we highlight several areas of active research where inquiry into phloem physiology has increased our understanding of whole plant function and ecological processes. We consider how xylem-phloem interactions impact plant drought tolerance and reproduction, how phloem transport influences carbon allocation in trees and carbon cycling in ecosystems and how phloem function mediates plant relations with insects, pests, microbes and symbiotes. We argue that in spite of challenges that exist in studying phloem physiology, it is critical that we consider the role of this dynamic vascular system when examining the relationship between plants and their biotic and abiotic environment. PMID:26147312

  8. Ecological context and metapopulation dynamics affect sex-ratio variation among dioecious plant populations

    PubMed Central

    Field, David L.; Pickup, Melinda; Barrett, Spencer C. H.

    2013-01-01

    Background and Aims Populations of dioecious flowering plants commonly exhibit heterogeneity in sex ratios and deviations from the equilibrium expectation of equal numbers of females and males. Yet the role of ecological and demographic factors in contributing towards biased sex ratios is currently not well understood. Methods Species-level studies from the literature were analysed to investigate ecological correlates of among-population sex-ratio variation and metapopulation models and empirical data were used to explore the influence of demography and non-equilibrium conditions on flowering sex ratios. Key Results The survey revealed significant among-population heterogeneity in sex ratios and this was related to the degree of sampling effort. For some species, sex-ratio bias was associated with the proportion of non-reproductive individuals, with greater male bias in populations with a lower proportion of individuals that were flowering. Male-biased ratios were also found at higher altitudes and latitudes, and in more xeric sites. Simulations and empirical data indicated that clonal species exhibited greater heterogeneity in sex ratios than non-clonal species as a result of their slower approach to equilibrium. The simulations also indicated the importance of interactions between reproductive mode and founder effects, with greater departures from equilibrium in clonal populations with fewer founding individuals. Conclusions The results indicate that sex-based differences in costs of reproduction and non-equilibrium conditions can each play important roles in affecting flowering sex ratios in populations of dioecious plants. PMID:23444124

  9. Plant Reproduction: AMOR Enables Males to Respond to Female Signals.

    PubMed

    Dresselhaus, Thomas; Coimbra, Silvia

    2016-04-25

    The pollen tube of flowering plants undertakes a long journey to transport two sperm cells for double fertilization. New work on pollen tube guidance has identified an arabinogalactan-derived ovular factor that primes tubes to respond to female gametophyte-secreted attraction signals. PMID:27115687

  10. Experimental charcoalification of plant reproductive organs: Taphonomic implications for taxonomic information loss

    SciTech Connect

    Lupia, R. )

    1992-01-01

    Charcoalification can preserve reproductive organs of plants in exceptional detail, but it has not been clear to what extent these taxonomically important structures suffer non-allometric size reduction during this process. To address this problem, seven angiosperm and two gymnosperm species were buried in sand and experimentally charcoalified in a muffle furnace at 325--350 degrees Celsius for two hours, and percent size reduction measured. Carpels, stamens, and petals never shrank by the same amount for a given angiosperm species. To determine the effect of different periods of heating on organs, one angiosperm species was treated for 0.5, 1, 2, 4, and 6 hours. Organs continued to shrink over this entire period without reaching a plateau. This is important in designing future experiments, and in terms of interpreting fossils, since heat treatment varies across a single site in natural fires. Observations made during this study suggest that some carpels and petals never become charcoalified, that stamens are particularly susceptible to fragmentation after charcoalification, that some organs show predictable damage which is correlated with time, and that the saturation of a structure with water can significantly retard charcoalification for heat exposure of less than one hour. These factors may severely affect the entry of the charred remains into the fossil record. Despite the suggestion that female structures can be expected to shrink the least, it is impossible to prescribe quantitative correction factors to permit accurate reconstructions without constraining additional variables such as temperature and duration of heating.

  11. Cross-talk between environmental stresses and plant metabolism during reproductive organ abscission

    PubMed Central

    Sawicki, Mélodie; Aït Barka, Essaïd; Clément, Christophe; Vaillant-Gaveau, Nathalie; Jacquard, Cédric

    2015-01-01

    In plants, flowering is a crucial process for reproductive success and continuity of the species through time. Fruit production requires the perfect development of reproductive structures. Abscission, a natural process, can occur to facilitate shedding of no longer needed, infected, or damaged organs. If stress occurs during flower development, abscission can intervene at flower level, leading to reduced yield. Flower abscission is a highly regulated developmental process simultaneously influenced and activated in response to exogenous (changing environmental conditions, interactions with microorganisms) and endogenous (physiological modifications) stimuli. During climate change, plant communities will be more susceptible to environmental stresses, leading to increased flower and fruit abscission, and consequently a decrease in fruit yield. Understanding the impacts of stress on the reproductive phase is therefore critical for managing future agricultural productivity. Here, current knowledge on flower/fruit abscission is summarized by focusing specifically on effects of environmental stresses leading to this process in woody plants. Many of these stresses impair hormonal balance and/or carbohydrate metabolism, but the exact mechanisms are far from completely known. Hormones are the abscission effectors and the auxin/ethylene balance is of particular importance. The carbohydrate pathway is the result of complex regulatory processes involving the balance between photosynthesis and mobilization of reserves. Hormones and carbohydrates together participate in complex signal transduction systems, especially in response to stress. The available data are discussed in relation to reproductive organ development and the process of abscission. PMID:25711702

  12. Chromatin dynamics during cellular differentiation in the female reproductive lineage of flowering plants.

    PubMed

    Baroux, Célia; Autran, Daphné

    2015-07-01

    Sexual reproduction in flowering plants offers a number of remarkable aspects to developmental biologists. First, the spore mother cells - precursors of the plant reproductive lineage - are specified late in development, as opposed to precocious germline isolation during embryogenesis in most animals. Second, unlike in most animals where meiosis directly produces gametes, plant meiosis entails the differentiation of a multicellular, haploid gametophyte, within which gametic as well as non-gametic accessory cells are formed. These observations raise the question of the factors inducing and modus operandi of cell fate transitions that originate in floral tissues and gametophytes, respectively. Cell fate transitions in the reproductive lineage imply cellular reprogramming operating at the physiological, cytological and transcriptome level, but also at the chromatin level. A number of observations point to large-scale chromatin reorganization events associated with cellular differentiation of the female spore mother cells and of the female gametes. These include a reorganization of the heterochromatin compartment, the genome-wide alteration of the histone modification landscape, and the remodeling of nucleosome composition. The dynamic expression of DNA methyltransferases and actors of small RNA pathways also suggest additional, global epigenetic alterations that remain to be characterized. Are these events a cause or a consequence of cellular differentiation, and how do they contribute to cell fate transition? Does chromatin dynamics induce competence for immediate cellular functions (meiosis, fertilization), or does it also contribute long-term effects in cellular identity and developmental competence of the reproductive lineage? This review attempts to review these fascinating questions. PMID:26031902

  13. Cross-talk between environmental stresses and plant metabolism during reproductive organ abscission.

    PubMed

    Sawicki, Mélodie; Aït Barka, Essaïd; Clément, Christophe; Vaillant-Gaveau, Nathalie; Jacquard, Cédric

    2015-04-01

    In plants, flowering is a crucial process for reproductive success and continuity of the species through time. Fruit production requires the perfect development of reproductive structures. Abscission, a natural process, can occur to facilitate shedding of no longer needed, infected, or damaged organs. If stress occurs during flower development, abscission can intervene at flower level, leading to reduced yield. Flower abscission is a highly regulated developmental process simultaneously influenced and activated in response to exogenous (changing environmental conditions, interactions with microorganisms) and endogenous (physiological modifications) stimuli. During climate change, plant communities will be more susceptible to environmental stresses, leading to increased flower and fruit abscission, and consequently a decrease in fruit yield. Understanding the impacts of stress on the reproductive phase is therefore critical for managing future agricultural productivity. Here, current knowledge on flower/fruit abscission is summarized by focusing specifically on effects of environmental stresses leading to this process in woody plants. Many of these stresses impair hormonal balance and/or carbohydrate metabolism, but the exact mechanisms are far from completely known. Hormones are the abscission effectors and the auxin/ethylene balance is of particular importance. The carbohydrate pathway is the result of complex regulatory processes involving the balance between photosynthesis and mobilization of reserves. Hormones and carbohydrates together participate in complex signal transduction systems, especially in response to stress. The available data are discussed in relation to reproductive organ development and the process of abscission. PMID:25711702

  14. Late snowmelt delays plant development and results in lower reproductive success in the High Arctic.

    PubMed

    Cooper, Elisabeth J; Dullinger, Stefan; Semenchuk, Philipp

    2011-01-01

    In tundra areas where the growing season is short, any delay in the start of summer may have a considerable effect on plant development, growth and reproductive success. Climate models suggest long-term changes in winter precipitation in the Arctic, which may lead to deeper snow cover and a resultant delay in date of snow melt. In this paper, we investigated the role of snow depth and melt out date on the phenological development and reproductive success of vascular plants in Adventdalen, Svalbard (78° 10'N, 16° 06'E). Effects of natural variations in snow accumulation were demonstrated using two vegetation types (snow depth: meadow 21 cm, heath 32 cm), and fences were used to experimentally increase snow depth by over 1m. Phenological delay was greatest directly after snowmelt in the earlier phenological phases, and had the largest effect on the early development of those species which normally green-up early (i.e. Dryas, Papaver, Salix, Saxifraga). Compressed growing seasons and length of the reproductive period led to a reduced reproductive success in some of the study species. There were fewer flowers, fewer plots with dispersing seeds, and lower germination rates. This can have consequences for plant establishment and community composition in the long-term. PMID:21421357

  15. Cotyledon damage affects seed number through final plant size in the annual grassland species Medicago lupulina

    PubMed Central

    Zhang, Shiting; Zhao, Chuan; Lamb, Eric G.

    2011-01-01

    Background and Aims The effects of cotyledon damage on seedling growth and survival are relatively well established, but little is known about the effects on aspects of plant fitness such as seed number and size. Here the direct and indirect mechanisms linking cotyledon damage and plant fitness in the annual species Medicago lupulina are examined. Methods Growth and reproductive traits, including mature plant size, time to first flowering, flower number, seed number and individual seed mass were monitored in M. lupulina plants when zero, one or two cotyledons were removed at 7 d old. Structural equation modelling (SEM) was used to examine the mechanisms linking cotyledon damage to seed number and seed mass. Key Results Cotyledon damage reduced seed number but not individual seed mass. The primary mechanism was a reduction in plant biomass with cotyledon damage that in turn reduced seed number primarily through a reduction in flower numbers. Although cotyledon damage delayed flower initiation, it had little effect on seed number. Individual seed mass was not affected by cotyledon removal, but there was a trade-off between seed number and seed mass. Conclusions It is shown how a network of indirect mechanisms link damage to cotyledons and fitness in M. lupulina. Cotyledon damage had strong direct effects on both plant size and flowering phenology, but an analysis of the causal relationships among plant traits and fitness components showed that a reduction in plant size associated with cotyledon damage was an important mechanism influencing fitness. PMID:21196450

  16. Thiol-based redox regulation in sexual plant reproduction: new insights and perspectives

    PubMed Central

    Traverso, Jose A.; Pulido, Amada; Rodríguez-García, María I.; Alché, Juan D.

    2013-01-01

    The success of sexual reproduction in plants involves (i) the proper formation of the plant gametophytes (pollen and embryo sac) containing the gametes, (ii) the accomplishment of specific interactions between pollen grains and the stigma, which subsequently lead to (iii) the fusion of the gametes and eventually to (iv) the seed setting. Owing to the lack of mobility, plants have developed specific regulatory mechanisms to control all developmental events underlying the sexual plant reproduction according to environmental challenges. Over the last decade, redox regulation and signaling have come into sight as crucial mechanisms able to manage critical stages during sexual plant reproduction. This regulation involves a complex redox network which includes reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione and other classic buffer molecules or antioxidant proteins, and some thiol/disulphide-containing proteins belonging to the thioredoxin superfamily, like glutaredoxins (GRXs) or thioredoxins (TRXs). These proteins participate as critical elements not only in the switch between the mitotic to the meiotic cycle but also at further developmental stages of microsporogenesis. They are also implicated in the regulation of pollen rejection as the result of self-incompatibility. In addition, they display precise space-temporal patterns of expression and are present in specific localizations like the stigmatic papillae or the mature pollen, although their functions and subcellular localizations are not clear yet. In this review we summarize insights and perspectives about the presence of thiol/disulphide-containing proteins in plant reproduction, taking into account the general context of the cell redox network. PMID:24294217

  17. Effect of effluents of a thermal power plant complex on reproductive processs of a winter season weed

    SciTech Connect

    Khan, F.A.; Iqbal, M.; Ghouse, A.K.M. )

    1990-05-01

    The Kasimpur Thermal Power Plant Complex (located in the District Aligarh, Uttar Pradesh, India) runs on a low grade, sulphur rich, bituminous type of coal with a daily average consumption rte of about 3,192 metric tons during winter season. Its effluents, mainly consisting of oxides of sulphur, nitrogen and carbon as well as particulate matters, were noted to affect the reproductive behavior of Melilotus indica-a winter season weed growing wild as a component of a grassland community. The samples consisting of 10 plants were collected at monthly intervals from 5 sites located about 0.5, 2, 6, 12 and 20 km leaward from the Complex. Emergence of inflorescence was delayed at the polluted sites. However, fruit formation started simultaneously (in March) at all the five sites. The pollution induced senescence of floral buds, flowers and fruits, but did not alter markedly weight of seed and fruit.

  18. Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

    USGS Publications Warehouse

    Barboza, P.S.; Jorde, D.G.

    2002-01-01

    We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

  19. Selenium status affects selenoprotein expression, reproduction, and F₁ generation locomotor activity in zebrafish (Danio rerio).

    PubMed

    Penglase, Sam; Hamre, Kristin; Rasinger, Josef D; Ellingsen, Staale

    2014-06-14

    Se is an essential trace element, and is incorporated into selenoproteins which play important roles in human health. Mammalian selenoprotein-coding genes are often present as paralogues in teleost fish, and it is unclear whether the expression patterns or functions of these fish paralogues reflect their mammalian orthologues. Using the model species zebrafish (Danio rerio; ZF), we aimed to assess how dietary Se affects key parameters in Se metabolism and utilisation including glutathione peroxidase (GPX) activity, the mRNA expression of key Se-dependent proteins (gpx1a, gpx1b, sepp1a and sepp1b), oxidative status, reproductive success and F1 generation locomotor activity. From 27 d until 254 d post-fertilisation, ZF were fed diets with graded levels of Se ranging from deficient ( < 0·10 mg/kg) to toxic (30 mg/kg). The mRNA expression of gpx1a and gpx1b and GPX activity responded in a similar manner to changes in Se status. GPX activity and mRNA levels were lowest when dietary Se levels (0·3 mg/kg) resulted in the maximum growth of ZF, and a proposed bimodal mechanism in response to Se status below and above this dietary Se level was identified. The expression of the sepp1 paralogues differed, with only sepp1a responding to Se status. High dietary Se supplementation (30 mg/kg) decreased reproductive success, while the offspring of ZF fed above 0·3 mg Se/kg diet had lower locomotor activity than the other groups. Overall, the novel finding of low selenoprotein expression and activity coinciding with maximum body growth suggests that even small Se-induced variations in redox status may influence cellular growth rates. PMID:24666596

  20. Plant reproduction systems in microgravity: experimental data and hypotheses

    NASA Astrophysics Data System (ADS)

    Kordyum, E. L.

    Elucidation of the possibilities for higher plants to realize complete ontogenesis, from seed to seed, and to propagate by seeds in microgravity, is a fundamental task of space biology connected with the working of the CELSS program. At present, there are results of only 6 spaceflight experiments with Arabidopsis thaliana, an ephemeral plant which will flower and fruit in orbit. Morphogenesis of generative organs occurs normally in microgravity, but unlike the ground control, buds and flowers mainly contain sterile elements of the androecium and gynoecium which degenerate at different stages of development in microgravity. Cytological peculiarities of male and female sterility in microgravity are similar to those occurring naturally during sexual differentiation. Many of the seed formed in microgravity are: 1) nutritional deficiency, 2) insufficient light, 3) intensification of the influence of the above-mentioned factors by microgravity, 4) disturbances of a hormonal nature, and 5) the absence of pollination and fertilization. Possible ways for testing these hypotheses and obtaining viable seeds in microgravity are discussed.

  1. Reproductive Ecology and Severe Pollen Limitation in the Polychromic Tundra Plant, Parrya nudicaulis (Brassicaceae)

    PubMed Central

    Fulkerson, Justin R.; Whittall, Justen B.; Carlson, Matthew L.

    2012-01-01

    Pollen limitation is predicted to be particularly severe in tundra habitats. Numerous reproductive patterns associated with alpine and arctic species, particularly mechanisms associated with reproductive assurance, are suggested to be driven by high levels of pollen limitation. We studied the reproductive ecology of Parrya nudicaulis, a species with relatively large sexual reproductive investment and a wide range of floral pigmentation, in tundra habitats in interior montane Alaska to estimate the degree of pollen limitation. The plants are self-compatible and strongly protandrous, setting almost no seed in the absence of pollinators. Supplemental hand pollinations within pollinator exclusion cages indicated no cage effect on seed production. Floral visitation rates were low in both years of study and particularly infrequent in 2010. A diversity of insects visited P. nudicaulis, though syrphid and muscid flies composed the majority of all visits. Pollen-ovule ratios and levels of heterozygosity are consistent with a mixed mating system. Pollen limitation was severe; hand pollinations increased seed production per plant five-fold. Seed-to-ovule ratios remained low following hand pollinations, indicating resource limitation is likely to also be responsible for curtailing seed set. We suggest that pollen limitation in P. nudicaulis may be the result of selection favoring an overproduction of ovules as a bet-hedging strategy in this environmental context of highly variable pollen receipt. PMID:22427886

  2. Genetically Determined Dosage of Follicle-Stimulating Hormone (FSH) Affects Male Reproductive Parameters

    PubMed Central

    Grigorova, Marina; Punab, Margus; Ẑilaitienė, Birutė; Erenpreiss, Juris; Ausmees, Kristo; Matuleviĉius, Valentinas; Tsarev, Igor; Jørgensen, Niels

    2011-01-01

    Context: The detailed role of FSH in contributing to male testicular function and fertility has been debated. We have previously identified the association between the T-allele of the FSHB promoter polymorphism (rs10835638; G/T, −211 bp from the mRNA start) and significantly reduced male serum FSH. Objective: In the current study, the T-allele carriers of the FSHB −211 G/T single nucleotide polymorphism represented a natural model for documenting downstream phenotypic consequences of insufficient FSH action. Design and Subjects: We genotyped rs10835638 in the population-based Baltic cohort of young men (n = 1054; GG carriers, n = 796; GT carriers, n = 244; TT carriers, n = 14) recruited by Andrology Centres in Tartu, Estonia; Riga, Latvia; and Kaunas, Lithuania. Marker-trait association testing was performed using linear regression (additive, recessive models) adjusted by age, body mass index, smoking, and recruitment center. Results: Serum hormones directly correlated with the T-allele dosage of rs10835638 included FSH (additive model, P = 1.11 × 10−6; T-allele effect, −0.41 IU/liter), inhibin-B (P = 2.16 × 10−3; T-allele effect, −14.67 pg/ml), and total testosterone (P = 9.30 × 10−3; T-allele effect, −1.46 nmol/liter). Parameters altered only among TT homozygotes were reduced testicular volume (recessive model, P = 1.19 × 10−4; TT genotype effect, −9.47 ml) and increased serum LH (P = 2.25 × 10−2; TT genotype effect, 1.07 IU/liter). The carrier status of rs10835638 alternative genotypes did not affect sperm motility and morphology, calculated free testosterone, serum SHBG, and estradiol concentrations. Conclusion: We showed for the first time that genetically determined low FSH may have wider downstream effects on the male reproductive system, including impaired testes development, altered testicular hormone levels (inhibin-B, total testosterone, LH), and affected male reproductive potential. PMID:21733993

  3. Modulation of diabetes-mellitus-induced male reproductive dysfunctions in experimental animal models with medicinal plants

    PubMed Central

    Jain, Gyan Chand; Jangir, Ram Niwas

    2014-01-01

    Today diabetes mellitus has emerged as a major healthcare problem throughout the world. It has recently broken the age barrier and has been diagnosed in younger people also. Sustained hyperglycemia is associated with many complications including male reproductive dysfunctions and infertility. Numerous medicinal plants have been used for the management of the diabetes mellitus in various traditional system of medicine and in folklore worldwide as they are a rich source of bioactive phytoconstituents, which lower blood glucose level and/or also act as antioxidants resulting in the amelioration of oxidative-stress-induced diabetic complications. The present review describes the ameliorative effects of medicinal plants or their products, especially on male reproductive dysfunctions, in experimental diabetic animal models. PMID:25125884

  4. Effects of acid precipitation on reproduction in alpine plant species. [Erythronium grandiflorum; Aquilegia caerulea

    SciTech Connect

    McKenna, M.A.; Hille-Salgueiro, M.; Musselman, R.C. Dept. of Agriculture, Fort Collins, CO )

    1990-01-01

    A series of experiments were designed to determine the impact of acid rain on plant reproductive processes, a critical component of a species life history. Research was carried out in herbaceous alpine communities at the USDA (United States Department of Agriculture) Forest Service Glacier Lakes Ecosystem Experiments Site in the Snowy Mts. of Wyoming. A range of species were surveyed to monitor the sensitivity of pollen to acidification during germination and growth, and all species demonstrated reduced in vitro pollen germination in acidified media. Field pollinations were carried out in Erythronium grandiflorum and Aquilegia caerulea to determine the reproductive success of plants exposed to simulated ambient precipitation (pH 5.6) or simulated acid precipitation (pH 3.6) prior to pollination. In Erythronium, no differences were observed in seed set and seed weight of fruits resulting from the two pollination treatments. In Aquilegia, fruits resulting from the acid spray treatment produced fewer seeds and lighter seeds.

  5. Life cycle specialization of filamentous pathogens - colonization and reproduction in plant tissues.

    PubMed

    Haueisen, Janine; Stukenbrock, Eva H

    2016-08-01

    Filamentous plant pathogens explore host tissues to obtain nutrients for growth and reproduction. Diverse strategies for tissue invasion, defense manipulation, and colonization of inter and intra-cellular spaces have evolved. Most research has focused on effector molecules, which are secreted to manipulate plant immunity and facilitate infection. Effector genes are often found to evolve rapidly in response to the antagonistic host-pathogen co-evolution but other traits are also subject to adaptive evolution during specialization to the anatomy, biochemistry and ecology of different plant hosts. Although not directly related to virulence, these traits are important components of specialization but little is known about them. We present and discuss specific life cycle traits that facilitate exploration of plant tissues and underline the importance of increasing our insight into the biology of plant pathogens. PMID:27153045

  6. Ungulate Reproductive Parameters Track Satellite Observations of Plant Phenology across Latitude and Climatological Regimes

    PubMed Central

    Stoner, David C.; Sexton, Joseph O.; Nagol, Jyoteshwar; Bernales, Heather H.; Edwards, Thomas C.

    2016-01-01

    The effect of climatically-driven plant phenology on mammalian reproduction is one key to predicting species-specific demographic responses to climate change. Large ungulates face their greatest energetic demands from the later stages of pregnancy through weaning, and so in seasonal environments parturition dates should match periods of high primary productivity. Interannual variation in weather influences the quality and timing of forage availability, which can influence neonatal survival. Here, we evaluated macro-scale patterns in reproductive performance of a widely distributed ungulate (mule deer, Odocoileus hemionus) across contrasting climatological regimes using satellite-derived indices of primary productivity and plant phenology over eight degrees of latitude (890 km) in the American Southwest. The dataset comprised > 180,000 animal observations taken from 54 populations over eight years (2004–2011). Regionally, both the start and peak of growing season (“Start” and “Peak”, respectively) are negatively and significantly correlated with latitude, an unusual pattern stemming from a change in the dominance of spring snowmelt in the north to the influence of the North American Monsoon in the south. Corresponding to the timing and variation in both the Start and Peak, mule deer reproduction was latest, lowest, and most variable at lower latitudes where plant phenology is timed to the onset of monsoonal moisture. Parturition dates closely tracked the growing season across space, lagging behind the Start and preceding the Peak by 27 and 23 days, respectively. Mean juvenile production increased, and variation decreased, with increasing latitude. Temporally, juvenile production was best predicted by primary productivity during summer, which encompassed late pregnancy, parturition, and early lactation. Our findings offer a parsimonious explanation of two key reproductive parameters in ungulate demography, timing of parturition and mean annual production

  7. Ungulate Reproductive Parameters Track Satellite Observations of Plant Phenology across Latitude and Climatological Regimes.

    PubMed

    Stoner, David C; Sexton, Joseph O; Nagol, Jyoteshwar; Bernales, Heather H; Edwards, Thomas C

    2016-01-01

    The effect of climatically-driven plant phenology on mammalian reproduction is one key to predicting species-specific demographic responses to climate change. Large ungulates face their greatest energetic demands from the later stages of pregnancy through weaning, and so in seasonal environments parturition dates should match periods of high primary productivity. Interannual variation in weather influences the quality and timing of forage availability, which can influence neonatal survival. Here, we evaluated macro-scale patterns in reproductive performance of a widely distributed ungulate (mule deer, Odocoileus hemionus) across contrasting climatological regimes using satellite-derived indices of primary productivity and plant phenology over eight degrees of latitude (890 km) in the American Southwest. The dataset comprised > 180,000 animal observations taken from 54 populations over eight years (2004-2011). Regionally, both the start and peak of growing season ("Start" and "Peak", respectively) are negatively and significantly correlated with latitude, an unusual pattern stemming from a change in the dominance of spring snowmelt in the north to the influence of the North American Monsoon in the south. Corresponding to the timing and variation in both the Start and Peak, mule deer reproduction was latest, lowest, and most variable at lower latitudes where plant phenology is timed to the onset of monsoonal moisture. Parturition dates closely tracked the growing season across space, lagging behind the Start and preceding the Peak by 27 and 23 days, respectively. Mean juvenile production increased, and variation decreased, with increasing latitude. Temporally, juvenile production was best predicted by primary productivity during summer, which encompassed late pregnancy, parturition, and early lactation. Our findings offer a parsimonious explanation of two key reproductive parameters in ungulate demography, timing of parturition and mean annual production, across

  8. Reproductive Hazards

    MedlinePlus

    ... such as lead and mercury Chemicals such as pesticides Cigarettes Some viruses Alcohol For men, a reproductive hazard can affect the sperm. For a woman, a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. ...

  9. Reproductive Hazards

    MedlinePlus

    ... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

  10. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals

    PubMed Central

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-01-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  11. Female reproductive function in areas affected by radiation after the Chernobyl power station accident

    SciTech Connect

    Kulakov, V.I.; Sokur, T.N.; Volobuev, A.I.

    1993-07-01

    This paper reports the results of a comprehensive survey of the effects of the accidental release of radiation caused by the accident at the Chernobyl nuclear power station in April 1986. The accident and the resulting release of radiation and radioactive products into the atmosphere produced the most serious environmental contamination so far recorded. We have concentrated on evaluating the outcomes and health risks to women, their reproductive situation, and consequences for their progeny. We have concentrated on two well-defined areas: the Chechersky district of the Gomel region in Belorussia and the Polessky district of the Kiev region in the Ukraine. A number of investigations were carried out on 688 pregnant women and their babies, and data were obtained from 7000 labor histories of the development of newborns for a period of 8 years (3 years before the accident and 5 years after it). Parameters examined included birth rate, thyroid pathology, extragenital pathology such as anemias, renal disorders, hypertension, and abnormalities in the metabolism of fats, complications of gestation, spontaneous abortions, premature deliveries, perinatal morbidity and mortality, stillbirths and early neonatal mortality, infections and inflammatory diseases, neurological symptoms and hemic disturbances in both mothers and infants, trophic anomalies, and biochemical and structural changes in the placenta. Several exogenous, complicating influences were also considered such as psycho-emotional factors, stress, lifestyle changes, and others caused directly by the hazardous situation and by its consequences such as treatment, removal from affected areas, etc. 9 figs.

  12. Prenatal exposure to di-(2-ethylhexyl) phthalate (DEHP) affects reproductive outcomes in female mice.

    PubMed

    Niermann, Sarah; Rattan, Saniya; Brehm, Emily; Flaws, Jodi A

    2015-06-01

    This study tested the hypothesis that prenatal DEHP exposure affects female reproduction. To test this hypothesis, pregnant female CD-1 mice were orally dosed daily with tocopherol-stripped corn oil (vehicle control) or DEHP (20 μg/kg/day-750 mg/kg/day) from gestation day 11-birth. Pups were counted, weighed, and sexed at birth, ovaries were subjected to evaluations of follicle numbers on postnatal days (PNDs) 8 and 21, and fertility was evaluated at 3-9 months. The results indicate that prenatal DEHP exposure increased male-to-female ratio compared to controls. Prenatal DEHP exposure also increased preantral follicle numbers at PND 21 compared to controls. Further, 22.2% of the 20 μg/kg/day treated animals took longer than 5 days to get pregnant at 3 months and 28.6% of the 750 mg/kg/day treated animals lost some of their pups at 6 months. Thus, prenatal DEHP exposure alters F1 sex ratio, increases preantral follicle numbers, and causes some breeding abnormalities. PMID:25765777

  13. Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals.

    PubMed

    Bowen, William D; den Heyer, Cornelia E; McMillan, Jim I; Iverson, Sara J

    2015-04-01

    Offspring size affects survival and subsequent reproduction in many organisms. However, studies of offspring size in large mammals are often limited to effects on juveniles because of the difficulty of following individuals to maturity. We used data from a long-term study of individually marked gray seals (Halichoerus grypus; Fabricius, 1791) to test the hypothesis that larger offspring have higher survival to recruitment and are larger and more successful primiparous mothers than smaller offspring. Between 1998 and 2002, 1182 newly weaned female pups were branded with unique permanent marks on Sable Island, Canada. Each year through 2012, all branded females returning to the breeding colony were identified in weekly censuses and a subset were captured and measured. Females that survived were significantly longer offspring than those not sighted, indicating size-selective mortality between weaning and recruitment. The probability of female survival to recruitment varied among cohorts and increased nonlinearly with body mass at weaning. Beyond 51.5 kg (mean population weaning mass) weaning mass did not influence the probability of survival. The probability of female survival to recruitment increased monotonically with body length at weaning. Body length at primiparity was positively related to her body length and mass at weaning. Three-day postpartum mass (proxy for birth mass) of firstborn pups was also positively related to body length of females when they were weaned. However, females that were longer or heavier when they were weaned did not wean heavier firstborn offspring. PMID:25897381

  14. The dynamics of resource allocation and costs of reproduction in a sexually dimorphic, wind-pollinated dioecious plant.

    PubMed

    Teitel, Z; Pickup, M; Field, D L; Barrett, S C H

    2016-01-01

    Sexual dimorphism in resource allocation is expected to change during the life cycle of dioecious plants because of temporal differences between the sexes in reproductive investment. Given the potential for sex-specific differences in reproductive costs, resource availability may contribute to variation in reproductive allocation in females and males. Here, we used Rumex hastatulus, a dioecious, wind-pollinated annual plant, to investigate whether sexual dimorphism varies with life-history stage and nutrient availability, and determine whether allocation patterns differ depending on reproductive commitment. To examine if the costs of reproduction varied between the sexes, reproduction was either allowed or prevented through bud removal, and biomass allocation was measured at maturity. In a second experiment to assess variation in sexual dimorphism across the life cycle, and whether this varied with resource availability, plants were grown in high and low nutrients and allocation to roots, aboveground vegetative growth and reproduction were measured at three developmental stages. Males prevented from reproducing compensated with increased above- and belowground allocation to a much larger degree than females, suggesting that male reproductive costs reduce vegetative growth. The proportional allocation to roots, reproductive structures and aboveground vegetative growth varied between the sexes and among life-cycle stages, but not with nutrient treatment. Females allocated proportionally more resources to roots than males at peak flowering, but this pattern was reversed at reproductive maturity under low-nutrient conditions. Our study illustrates the importance of temporal dynamics in sex-specific resource allocation and provides support for high male reproductive costs in wind-pollinated plants. PMID:25865555

  15. Survey of Reproductive Host Plants of Bemisia tabaci (Hemiptera: Aleyrodidae) in Egypt, Including New Host Records

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plants can affect the population dynamics of the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the plants can be potential sources of numerous whitefly-vectored viruses. This important pest attacks a wide range of agricultural plants, and feed on an extensive number of feral species of...

  16. Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Gill, Robert E., Jr.; Mulcahy, Daniel M.; Tibbitts, T. Lee; Kentie, Rosemarie; Gerritsen, Gerrit J.; Bruinzeel, Leo W.; Tijssen, David C.; Harwood, Christopher M.; Piersma, Theunis

    2014-01-01

    Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds

  17. Medicinal plants used in British Columbia, Canada for reproductive health in pets.

    PubMed

    Lans, Cheryl; Turner, Nancy; Brauer, Gerhard; Khan, Tonya

    2009-08-01

    In 2003, semi-structured interviews were conducted in British Columbia, Canada with participants obtained using a purposive sample on the ethnoveterinary remedies used for animals. Twenty-nine participants provided the information in this paper on the ethnoveterinary remedies used for reproductive health in dogs and cats. The plants used for pregnancy support and milk production in pets were raspberry-leaf (Rubus idaeus), motherwort (Leonurus cardiaca), flaxseed (Linum usitatissimum) and ginger (Zingiber officinale). Uterine infections were treated with black cohosh (Actaea racemosa) and goldenseal (Hydrastis canadensis). Most of the studies conducted on these plants have not been conducted on companion animals. PMID:19482367

  18. Host plant effects on development and reproduction of the glassy-winged sharpshooter, Homalodisca vitripennis (Homoptera: Cicadellidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development, survivorship, longevity, reproduction and life table parameters of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar), were examined in the laboratory using three host plants, sunflower (Helianthus annuus L.), Chrysanthemum morifolium L. and euonymus (Euonymus japonica Thu...

  19. Can aircraft noise less than or equal 115 to dBA adversely affect reproductive outcome in USAF women?

    NASA Astrophysics Data System (ADS)

    Brubaker, P. A.

    1985-06-01

    It has been suggested, mainly through animal studies, that exposure to high noise levels may be associated with lower birth weight, reduced gestational length and other adverse reproductive outcomes. Few studies have been done on humans to show this association. The Air Force employs pregnant women in areas where there is a high potential for exposure to high noise levels. This study proposes a method to determine if there is an association between high frequency noise levels or = 115 dBA and adverse reproductive outcomes through a review of records and self-administered questionnaires in a case-comparison design. Prevelance rates will be calculated and a multiple logistic regression analysis computed for the independent variables that can affect reproduction.

  20. Chromatin dynamics during cellular differentiation in the female reproductive lineage of flowering plants

    PubMed Central

    Baroux, Célia; Autran, Daphné

    2015-01-01

    Sexual reproduction in flowering plants offers a number of remarkable aspects to developmental biologists. First, the spore mother cells – precursors of the plant reproductive lineage – are specified late in development, as opposed to precocious germline isolation during embryogenesis in most animals. Second, unlike in most animals where meiosis directly produces gametes, plant meiosis entails the differentiation of a multicellular, haploid gametophyte, within which gametic as well as non-gametic accessory cells are formed. These observations raise the question of the factors inducing and modus operandi of cell fate transitions that originate in floral tissues and gametophytes, respectively. Cell fate transitions in the reproductive lineage imply cellular reprogramming operating at the physiological, cytological and transcriptome level, but also at the chromatin level. A number of observations point to large-scale chromatin reorganization events associated with cellular differentiation of the female spore mother cells and of the female gametes. These include a reorganization of the heterochromatin compartment, the genome-wide alteration of the histone modification landscape, and the remodeling of nucleosome composition. The dynamic expression of DNA methyltransferases and actors of small RNA pathways also suggest additional, global epigenetic alterations that remain to be characterized. Are these events a cause or a consequence of cellular differentiation, and how do they contribute to cell fate transition? Does chromatin dynamics induce competence for immediate cellular functions (meiosis, fertilization), or does it also contribute long-term effects in cellular identity and developmental competence of the reproductive lineage? This review attempts to review these fascinating questions. PMID:26031902

  1. A highly infective plant-associated bacterium influences reproductive rates in pea aphids

    PubMed Central

    Hendry, Tory A.; Clark, Kelley J.; Baltrus, David A.

    2016-01-01

    Pea aphids, Acyrthosiphon pisum, have the potential to increase reproduction as a defence against pathogens, though how frequently this occurs or how infection with live pathogens influences this response is not well understood. Here we determine the minimum infective dose of an environmentally common bacterium and possible aphid pathogen, Pseudomonas syringae, to determine the likelihood of pathogenic effects to pea aphids. Additionally, we used P. syringae infection to investigate how live pathogens may alter reproductive rates. We found that oral bacterial exposure decreased subsequent survival of aphids in a dose-dependent manner and we estimate that ingestion of less than 10 bacterial cells is sufficient to increase aphid mortality. Pathogen dose was positively related to aphid reproduction. Aphids exposed to low bacterial doses showed decreased, although statistically indistinguishable, fecundity compared to controls. Aphids exposed to high doses reproduced significantly more than low dose treatments and also more, but not significantly so, than controls. These results are consistent with previous studies suggesting that pea aphids may use fecundity compensation as a response to pathogens. Consequently, even low levels of exposure to a common plant-associated bacterium may therefore have significant effects on pea aphid survival and reproduction. PMID:26998321

  2. Cyclic variations in nitrogen uptake rate in soybean plants: uptake during reproductive growth

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; Raper, C. D. Jr; Henry, L. T.; Raper CD, J. r. (Principal Investigator)

    1990-01-01

    Net uptake of NO3- by non-nodulated soybean plants [Glycine max (L.) Merr. cv. Ransom] growing in flowing hydroponic culture was measured daily during a 63 d period of reproductive development between the first florally inductive photoperiod and [unknown word] seed growth. Removal of NO3- from a replenished solution containing 1.0 mol m-3 NO3- was determined by ion chromatography. Uptake of NO3- continued throughout reproductive development. The net uptake rate of NO3- cycled between maxima and minima with a periodicity of oscillation of 3 to 7 d during the floral stage and about 6 d during the fruiting stage. Coupled with increasing concentrations of carbon and C : N ratios in tissues, the oscillations in net uptake rates of NO3- are evidence that the demand for carbohydrate by reproductive organs is contingent on the availability of nitrogen in the shoot pool rather than that the demand for nitrogen follows the flux of carbohydrate into reproductive tissues.

  3. A highly infective plant-associated bacterium influences reproductive rates in pea aphids.

    PubMed

    Hendry, Tory A; Clark, Kelley J; Baltrus, David A

    2016-02-01

    Pea aphids, Acyrthosiphon pisum, have the potential to increase reproduction as a defence against pathogens, though how frequently this occurs or how infection with live pathogens influences this response is not well understood. Here we determine the minimum infective dose of an environmentally common bacterium and possible aphid pathogen, Pseudomonas syringae, to determine the likelihood of pathogenic effects to pea aphids. Additionally, we used P. syringae infection to investigate how live pathogens may alter reproductive rates. We found that oral bacterial exposure decreased subsequent survival of aphids in a dose-dependent manner and we estimate that ingestion of less than 10 bacterial cells is sufficient to increase aphid mortality. Pathogen dose was positively related to aphid reproduction. Aphids exposed to low bacterial doses showed decreased, although statistically indistinguishable, fecundity compared to controls. Aphids exposed to high doses reproduced significantly more than low dose treatments and also more, but not significantly so, than controls. These results are consistent with previous studies suggesting that pea aphids may use fecundity compensation as a response to pathogens. Consequently, even low levels of exposure to a common plant-associated bacterium may therefore have significant effects on pea aphid survival and reproduction. PMID:26998321

  4. The impact of environmental stress on male reproductive development in plants: biological processes and molecular mechanisms

    PubMed Central

    de Storme, Nico; Geelen, Danny

    2014-01-01

    In plants, male reproductive development is extremely sensitive to adverse climatic environments and (a)biotic stress. Upon exposure to stress, male gametophytic organs often show morphological, structural and metabolic alterations that typically lead to meiotic defects or premature spore abortion and male reproductive sterility. Depending on the type of stress involved (e.g. heat, cold, drought) and the duration of stress exposure, the underlying cellular defect is highly variable and either involves cytoskeletal alterations, tapetal irregularities, altered sugar utilization, aberrations in auxin metabolism, accumulation of reactive oxygen species (ROS; oxidative stress) or the ectopic induction of programmed cell death (PCD). In this review, we present the critically stress-sensitive stages of male sporogenesis (meiosis) and male gametogenesis (microspore development), and discuss the corresponding biological processes involved and the resulting alterations in male reproduction. In addition, this review also provides insights into the molecular and/or hormonal regulation of the environmental stress sensitivity of male reproduction and outlines putative interaction(s) between the different processes involved. PMID:23731015

  5. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population

    PubMed Central

    Bearhop, Stuart; Hilton, Geoff M.; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were ‘good’ prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  6. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population.

    PubMed

    Weegman, Mitch D; Bearhop, Stuart; Hilton, Geoff M; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were 'good' prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  7. Shift in egg-laying strategy to avoid plant defense leads to reproductive isolation in mutualistic and cheating yucca moths.

    PubMed

    Althoff, David M

    2014-01-01

    Through the process of ecological speciation, insect populations that adapt to new host plant species or to different plant tissues could speciate if such adaptations cause reproductive isolation. One of the key issues in this process is identifying the mechanisms by which adaptation in ecological traits leads directly to reproductive isolation. Here I show that within a radiation of specialist moths that pollinate and feed on yuccas, shifts in egg placement resulted in changes in female moth egg-laying structures that led to concomitant changes in male reproductive morphology. As pollinator moths evolved to circumvent the ability of yuccas to selectively abscise flowers that contain pollinator eggs, ovipositor length became shorter. Because mating occurs through the ovipositor, shortening of the ovipositor also led to significantly shorter and wider male intromittent organs. In instances where two pollinator moth species occur in sympatry and on the same host plant species, there is one short and one long ovipositor species that are reproductively isolated. Given that many plant-feeding insects lay eggs into plant tissues, changes in ovipositor morphology that lead to correlated changes in reproductive morphology may be a mechanism that maintains reproductive isolation among closely related species using the same host plant species. PMID:24117334

  8. Reproductive state affects hiding behaviour under risk of predation but not exploratory activity of female Spanish terrapins.

    PubMed

    Ibáñez, Alejandro; Marzal, Alfonso; López, Pilar; Martín, José

    2015-02-01

    Female investment during reproduction may reduce survivorship due to increased predation risk. During pregnancy, the locomotor performance of gravid females might be diminished due to the additional weight acquired. In addition, egg production may also increase thermoregulatory, metabolic and physiological costs. Also, pregnant females have greater potential fitness and should take fewer risks. Thus, females should ponder their reproductive state when considering their behavioural responses under risky situations. Here, we examine how reproductive state influence risk-taking behaviour in different contexts in female Spanish terrapins (Mauremys leprosa). We simulated predator attacks of different risk levels and measured the time that the turtles spent hiding entirely inside their own shells (i.e. appearance times). We also assessed the subsequent time after emergence from the shell that the turtles spent immobile monitoring for predators before starting to escape actively (i.e. waiting times). Likewise, we performed a novel-environment test and measured the exploratory activity of turtles. We found no correlations between appearance time, waiting time or exploratory activity, but appearance times were correlated across different risk levels. Only appearance time was affected by the reproductive state, where gravid females reappeared relatively later from their shells after a predator attack than non-gravid ones. Moreover, among gravid females, those carrying greater clutches tended to have longer appearance times. This suggests that only larger clutches could affect hiding behaviour in risky contexts. In contrast, waiting time spent scanning for predators and exploratory activity were not affected by the reproductive state. These differences between gravid and non-gravid females might be explained by the metabolic-physiological costs associated with egg production and embryo maintenance, as well as by the relatively higher potential fitness of gravid females. PMID

  9. Superiority of reproductive histories to sperm counts in detecting infertility at a dibromochloropropane manufacturing plant

    SciTech Connect

    Levine, R.J.; Blunden, P.B.; DalCorso, R.D.; Starr, T.B.; Ross, C.E.

    1983-08-01

    Sperm count distributions among exposed and control groups at a dibromochloropropane (DBCP) manufacturing plant were remarkably similar. Yet reproductive histories from 60 exposed men obtained in conjunction with the semen analyses indicated that fertility had been reduced during exposure. Ratios of observed to expected births or standardized fertility ratios (SFRs) were computed for reproductive experience at parities of 1 or greater. The SFR for the period at risk from DBCP exposure (SFR . 0.63) was significantly lower than those derived from the entire not-at-risk period (SFR . 1.21) or the portion related to nonexposed employment at the plant preceding exposure (SFR . 1.33). Significant reductions would have been evident at least 18 years prior to the year in which the histories were obtained. The effect on fertility seems to have been greatest during the initial period of DBCP production. Most fertility reduction occurred after 3.5 years of exposure. Fertility returned to normal following cessation of exposure (SFR . 1.18), although it appeared to remain subnormal for about two years. Wherever there is concern about the potential for adverse reproductive effects in the workplace, data suitable for fertility analyses should be collected during annual medical examinations.

  10. ANDROGENS AND ENVIRONMENTAL ANTIANDROGENS AFFECT REPRODUCTIVE DEVELOPMENT AND PLAY BEHAVIOR IN THE SPRAGUE-DAWLEY RAT

    EPA Science Inventory

    Abstract: In mammals, exposure to androgens early in development is essential for masculinization of the male reproductive phenotype. Male fetuses exposed to antiandrogens during perinatal life are permanently demasculinized in their morphology and physiology, whereas exposure to...

  11. Mortality affects adaptive allocation to growth and reproduction: field evidence from a guild of body snatchers

    PubMed Central

    2010-01-01

    Background The probability of being killed by external factors (extrinsic mortality) should influence how individuals allocate limited resources to the competing processes of growth and reproduction. Increased extrinsic mortality should select for decreased allocation to growth and for increased reproductive effort. This study presents perhaps the first clear cross-species test of this hypothesis, capitalizing on the unique properties offered by a diverse guild of parasitic castrators (body snatchers). I quantify growth, reproductive effort, and expected extrinsic mortality for several species that, despite being different species, use the same species' phenotype for growth and survival. These are eight trematode parasitic castrators—the individuals of which infect and take over the bodies of the same host species—and their uninfected host, the California horn snail. Results As predicted, across species, growth decreased with increased extrinsic mortality, while reproductive effort increased with increased extrinsic mortality. The trematode parasitic castrator species (operating stolen host bodies) that were more likely to be killed by dominant species allocated less to growth and relatively more to current reproduction than did species with greater life expectancies. Both genders of uninfected snails fit into the patterns observed for the parasitic castrator species, allocating as much to growth and to current reproduction as expected given their probability of reproductive death (castration by trematode parasites). Additionally, species differences appeared to represent species-specific adaptations, not general plastic responses to local mortality risk. Conclusions Broadly, this research illustrates that parasitic castrator guilds can allow unique comparative tests discerning the forces promoting adaptive evolution. The specific findings of this study support the hypothesis that extrinsic mortality influences species differences in growth and reproduction

  12. Native pollen thieves reduce the reproductive success of a hermaphroditic plant, Aloe maculata.

    PubMed

    Hargreaves, Anna L; Harder, Lawrence D; Johnson, Steven D

    2010-06-01

    Pollen is unique among floral rewards in functioning as both a carrier of gametes and an attractant and nutritious resource for floral visitors. Animals that collect pollen without pollinating (pollen thieves) could reduce siring success of thieved plants and cause pollen limitation of seed set at the population level; however, such impacts on plant reproduction have not been demonstrated experimentally. To test these effects we added hives of native honey bees (Apis mellifera scutellata) to populations of a primarily bird-pollinated plant, Aloe maculata, in eastern South Africa. In field and aviary trials, bee addition increased pollen removal from anthers but decreased pollen deposition on stigmas, and so reduced both male and female pollination components. Further, total seed production decreased with hive addition in the aviary experiment and in three of four field populations, indicating that population-level pollen theft can also compromise reproductive success. In the field, naturally occurring allodapine bees also seemed to act as pollen thieves, outweighing the effect of honey bee hive addition at one of the four aloe populations. Our results highlight the importance of social bees as pollen thieves, even of plants that have evolved in their presence, and the role of dichogamy in promoting pollen theft. Given the commonness of both social bees and dichogamy, pollen theft is likely a much more common influence on floral ecology and evolution than suggested by the sparse literature. PMID:20583711

  13. Reproductive rate, not dominance status, affects fecal glucocorticoid levels in breeding female meerkats.

    PubMed

    Barrette, Marie-France; Monfort, Steven L; Festa-Bianchet, Marco; Clutton-Brock, Tim H; Russell, Andrew F

    2012-04-01

    Glucocorticoid hormones (GCs) have been studied intensively to understand the associations between physiological stress and reproductive skew in animal societies. However, we have little appreciation of the range of either natural levels within and among individuals, or the associations among dominance status, reproductive rate and GCs levels during breeding. To address these shortcomings, we examined variation in fecal glucocorticoid metabolites (fGC) during breeding periods in free-ranging female meerkats (Suricata suricatta) over 11 years. The vast majority of variation in fGC levels was found within breeding events by the same female (~87%), with the remaining variation arising among breeding events and among females. Concentrations of fGC generally tripled as pregnancy progressed. However, females with a high reproductive rate, defined as those conceiving within a month following parturition (mean = 9 days postpartum), showed significant reductions in fGC in the final 2 weeks before parturition. Despite these reductions, females with a high reproductive rate had higher fGC levels at conception of the following litter than those breeding at a low rate. After controlling for the higher reproductive rate of dominants, we found no association between levels of fGC and either age or dominance status. Our results suggest that one should be cautious about interpreting associations between dominance status, reproductive skew and GCs levels, without knowledge of the natural variation in GCs levels within and among females. PMID:22210199

  14. Corridors affect plants, animals, and their interactions in fragmented landscapes.

    SciTech Connect

    Tewksbury, Joshua, J.; Levey, Douglas, J.; Haddad, Nick, M.; Sargent, Sarah; Orrock, John, L.; Weldon, Aimee; Danielson, Brent, J.; Brinkerhoff, Jory; Damschen, Ellen, I.; Townsend, Patricia

    2002-10-01

    Tewksbury, J.J., D.J. Levey, N.M. Haddad, S. Sargent, J.L. Orrock, A. Weldon, B.J. Danielson, J. Brinkerhoff, E.I. Damschen, and P. Townsend. 2002. Corridors affect plants, animals, and their interactions in fragmented landscapes. PNAS 99(20):12923-12926. Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plant-animal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. We demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant-animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes.

  15. Father's death does not affect growth and maturation but hinders reproduction: evidence from adolescent girls in post-war Estonia.

    PubMed

    Hõrak, Peeter; Valge, Markus

    2015-12-01

    The popular concept of predictive-adaptive responses poses that girls growing up without a father present in the family mature and start reproduction earlier because the father's absence is a cue for environmental harshness and uncertainty that favours switching to a precocious life-history strategy. Most studies supporting this concept have been performed in situations where the father's absence is caused by divorce or abandonment. Using a dataset of Estonian adolescent girls who had lost their fathers over the period of World War II, we show that father's death did not affect the rate of pubertal maturation (assessed on the basis of development of breasts and axillary hair) or growth. Father's death did not affect the age of first birth but, contrary to predictions, reduced lifetime reproductive success. Our findings thus do not support the concept of predictive-adaptive responses and suggest that alternative explanations for covariation between fatherlessness and early maturation are required. PMID:26673934

  16. Plant ecology. Anthropogenic environmental changes affect ecosystem stability via biodiversity.

    PubMed

    Hautier, Yann; Tilman, David; Isbell, Forest; Seabloom, Eric W; Borer, Elizabeth T; Reich, Peter B

    2015-04-17

    Human-driven environmental changes may simultaneously affect the biodiversity, productivity, and stability of Earth's ecosystems, but there is no consensus on the causal relationships linking these variables. Data from 12 multiyear experiments that manipulate important anthropogenic drivers, including plant diversity, nitrogen, carbon dioxide, fire, herbivory, and water, show that each driver influences ecosystem productivity. However, the stability of ecosystem productivity is only changed by those drivers that alter biodiversity, with a given decrease in plant species numbers leading to a quantitatively similar decrease in ecosystem stability regardless of which driver caused the biodiversity loss. These results suggest that changes in biodiversity caused by drivers of environmental change may be a major factor determining how global environmental changes affect ecosystem stability. PMID:25883357

  17. Reproductive success and contaminants in tree swallows (Tachycineta bicolor) breeding at a wastewater treatment plant.

    PubMed

    Dods, Patti L; Birmingham, Erinn M; Williams, Tony D; Ikonomou, Michael G; Bennie, Donald T; Elliott, John E

    2005-12-01

    The uptake and effects of contaminants were measured in the insectivorous tree swallow (Tachycineta bicolor) at a wastewater treatment site. The study examined reproductive, immunological, and growth endpoints in tree swallows exposed to chlorinated hydrocarbon contaminants and to 4-nonylphenol in wastewater lagoons at the Iona Wastewater Treatment Plant, Vancouver (BC, Canada). Clutch size was significantly lower in tree swallows breeding at Iona Island in 2000 and 2001 compared to the reference site. In 2000, fledging success was significantly lower and mean mass of nestling livers was significantly higher in the tree swallows breeding at the Iona Island Wastewater Treatment Plant. Additional factors that may influence reproductive success, such as parental provisioning and diet composition, did not differ significantly between sites. Levels of 4-nonylphenol detected in sediment and insects were elevated at the Iona Island Wastewater Treatment Plant (2000: lagoon sediment 82,000 ng/g dry wt, insects 310 ng/g wet wt; 2001: lagoon sediment 383,900 ng/g dry wt, insects 156 ng/g wet wt) compared to the reference site (2000: pond sediment 1,100 ng/g dry wt, insects not sampled; 2001: pond sediment 642 ng/g dry wt, insects 98 ng/g wet wt). These results indicate that tree swallows might be a useful indicator species for exposure to 4-nonylphenol at wastewater treatment sites: however, further work is necessary to determine the extent of uptake and effects of 4-nonylphenol in riparian insectivorous birds. PMID:16445092

  18. Survival, reproduction, and recruitment of woody plants after 14 years on a reforested landfill

    NASA Astrophysics Data System (ADS)

    Robinson, George R.; Handel, Steven N.; Schmalhofer, Victoria R.

    1992-03-01

    With the advent of modern sanitary landfill closure techniques, the opportunity exists for transforming municipal landfills into urban woodlands. While costs of fullscale reforestation are generally prohibitive, a modest planting of clusters of trees and shrubs could initiate or accelerate population expansions and natural plant succession from open field to diverse forest. However, among woody species that have been screened for use on landfills, these ecological potentials have not yet been investigated. We examined a 14-yr-old landfill plantation in New Jersey, USA, established to test tolerance of 19 species of trees and shrubs to landfill environments. We measured survivorship, reproduction, and recruitment within and around the experimental installation. Half of the original 190 plants were present, although survival and growth rates varied widely among species. An additional 752 trees and shrubs had colonized the plantation and its perimeter, as well as 2955 stems of vines. However, the great majority (>95%) of woody plants that had colonized were not progeny of the planted cohort, but instead belonged to 18 invading species, mostly native, bird-dispersed, and associated with intermediate stages of secondary plant succession. Based on this evidence, we recommend that several ecological criteria be applied to choices of woody species for the restoration of municipal landfills and similar degraded sites, in order to maximize rapid and economical establishment of diverse, productive woodlands.

  19. Polybrominated diphenyl ethers and multiple stressors influence the reproduction of free-ranging tree swallows (Tachycineta bicolor) nesting at wastewater treatment plants.

    PubMed

    Gilchrist, Tiffany T; Letcher, Robert J; Thomas, Philippe; Fernie, Kim J

    2014-02-15

    Reproductive success of birds is influenced by maternal factors, ambient temperatures, predation, food supply, and/or exposure to environmental contaminants e.g., flame retardants (FRs). Reproduction of tree swallows (Tachycineta bicolor) was compared among waste water treatment plants (WWTPs) and a reference reservoir in Ontario, Canada (2007-2010), to determine the importance of exposure to polybrominated diphenyl ether (PBDEs) FRs within a complex contaminant cocktail, relative to natural and biological factors known to influence avian reproduction. The birds primarily consumed insects emerging from the reference reservoir and WWTP outflows, where effluent mixed with receiving waters. FR egg concentrations were dominated by 5 PBDE congeners (∑5PBDEs): 2,2'.4,4',5-pentabromodiphenyl ether (BDE-99), 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2'4,4',6-pentabromodiphenyl ether (BDE-100), 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153), and 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154), with much lower concentrations of decabromodiphenylether (BDE-209), hexabromocyclododecane (HBCDD), and novel FRs. Although higher than ∑5PBDEs, polychlorinated biphenyls (PCBs) egg concentrations were unlikely to affect the swallows' reproduction. Clutch size and timing, fledging, breeding success, and predation, varied significantly among sites, generally being poorer at WWTP1 and better at WWTP2. The early reproductive stages were sensitive to some FRs at measured concentrations. The ∑5PBDEs, maternal age, and minimum ambient temperatures predicted onset of egg laying in the most parsimonious statistical model, and there were positive relationships between egg size and HBCDD or BDE-209 concentrations. However, there were no significant correlations with any reproductive measures, individual BDE congeners or low concentrations of novel FRs, in this first such report for novel FRs and wild birds. Tree swallows are passerines, and passerines may differ from birds of prey

  20. Sexual experience affects reproductive behavior and preoptic androgen receptors in male mice

    PubMed Central

    Swaney, William T.; Dubose, Brittany N.; Curley, James P.; Champagne, Frances A.

    2012-01-01

    Reproductive behavior in male rodents is made up of anticipatory and consummatory elements which are regulated in the brain by sensory systems, reward circuits and hormone signaling. Gonadal steroids play a key role in the regulation of male sexual behavior via steroid receptors in the hypothalamus and preoptic area. Typical patterns of male reproductive behavior have been characterized, however these are not fixed but are modulated by adult experience. We assessed the effects of repeated sexual experience on male reproductive behavior of C57BL/6 mice; including measures of olfactory investigation of females, mounting, intromission and ejaculation. The effects of sexual experience on the number of cells expressing either androgen receptor (AR) or estrogen receptor alpha (ERα) in the primary brain nuclei regulating male sexual behavior was also measured. Sexually experienced male mice engaged in less sniffing of females before initiating sexual behavior and exhibited shorter latencies to mount and intromit, increased frequency of intromission, and increased duration of intromission relative to mounting. No changes in numbers of ERα-positive cells were observed, however sexually experienced males had increased numbers of AR-positive cells in the medial preoptic area (MPOA); the primary regulatory nucleus for male sexual behavior. These results indicate that sexual experience results in a qualitative change in male reproductive behavior in mice that is associated with increased testosterone sensitivity in the MPOA and that this nucleus may play a key integrative role in mediating the effects of sexual experience on male behavior. PMID:22266118

  1. DIBROMOACETIC ACID AFFECTS REPRODUCTIVE COMPETENCE AND SPERM QUALITY IN THE MALE RAT

    EPA Science Inventory

    We have recently shown that Dibromoacetic acid (DBAA) alters sperm quality in short duration tests. n this study, male rats were gavaged with 0, 2, 10, 50, 250 mg DBAA/kg/d for up to 49 d. Interim. and terminal measurements of sperm quality & reproductive outcome were made. BAA c...

  2. Age and reproductive status of adult Varroa mites affect grooming success of honey bees.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated for the first time the grooming response of honey bees to different ages and reproductive statuses of varroa mites in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four different classes of mites: gravid, phoret...

  3. Benzyl isothiocyanate affects development, hatching and reproduction of the soybean cyst nematode Heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzyl isothiocyanate (BITC) applied at micromolar doses decreased Heterodera glycines J2 movement, H. glycines hatching, and reproduction of H. glycines on soybean, Glycine max. Direct exposure of J2 to 30 microM BITC caused an immediate decrease (17%; P < 0.05) in J2 movement relative to 1% methan...

  4. Within-species reproductive costs affect the asymmetry of satyrization in Drosophila.

    PubMed

    Yassin, A; David, J R

    2016-02-01

    Understanding how species interactions influence their distribution and evolution is a fundamental question in evolutionary biology. Theory suggests that asymmetric reproductive interference, in which one species induces higher reproductive costs on another species, may be more important in delimiting species boundaries than interspecific competition over resources. However, the underlying mechanisms of such asymmetry remain unclear. Here, we test whether differences in within-species reproductive costs determine the between-species asymmetry of costs using three allopatric Drosophila species belonging to the melanogaster subgroup. Our results support this hypothesis, especially in a pair of insular species. Males of one species that induce costs to their conspecific females led to a 5-fold increase of heterospecific females mortality with dead flies bearing spectacular large melanized wounds on their genitalia. Males of the other species were harmful neither to their conspecific nor heterospecific females. Comparative studies of within-species reproductive costs may therefore be a valuable tool for predicting between-species interactions and community structures. PMID:26538290

  5. Transgenerational interactions involving parental age and immune status affect female reproductive success in Drosophila melanogaster

    PubMed Central

    Nystrand, M.; Dowling, D. K.

    2014-01-01

    It is well established that the parental phenotype can influence offspring phenotypic expression, independent of the effects of the offspring's own genotype. Nonetheless, the evolutionary implications of such parental effects remain unclear, partly because previous studies have generally overlooked the potential for interactions between parental sources of non-genetic variance to influence patterns of offspring phenotypic expression. We tested for such interactions, subjecting male and female Drosophila melanogaster of two different age classes to an immune activation challenge or a control treatment. Flies were then crossed in all age and immune status combinations, and the reproductive success of their immune- and control-treated daughters measured. We found that daughters produced by two younger parents exhibited reduced reproductive success relative to those of other parental age combinations. Furthermore, immune-challenged daughters exhibited higher reproductive success when produced by immune-challenged relative to control-treated mothers, a pattern consistent with transgenerational immune priming. Finally, a complex interplay between paternal age and parental immune statuses influenced daughter's reproductive success. These findings demonstrate the dynamic nature of age- and immune-mediated parental effects, traceable to both parents, and regulated by interactions between parents and between parents and offspring. PMID:25253454

  6. Social Variables Affecting Mate Preferences, Copulation and Reproductive Outcome in a Pack of Free-Ranging Dogs

    PubMed Central

    Valsecchi, Paola; Natoli, Eugenia

    2014-01-01

    Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves. PMID:24905360

  7. Social variables affecting mate preferences, copulation and reproductive outcome in a pack of free-ranging dogs.

    PubMed

    Cafazzo, Simona; Bonanni, Roberto; Valsecchi, Paola; Natoli, Eugenia

    2014-01-01

    Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves. PMID:24905360

  8. How does childhood socioeconomic hardship affect reproductive strategy? Pathways of development

    PubMed Central

    Pearce, Mark S.; Sear, Rebecca

    2015-01-01

    Objectives In high‐income populations, evidence suggests that socioeconomic disadvantage early in life is correlated with reproductive strategy. Children growing up in unfavorable rearing environments tend to experience earlier sexual maturity and first births. Earlier first births may be associated with higher fertility, but links between socioeconomic disadvantage and larger family size have rarely been tested. The pathways through which early disadvantage influences reproduction are unknown. We test whether physiological factors link childhood adversity to age at first birth and total children. Methods Using data from the Newcastle Thousand Families Study, a 1947 British birth cohort, we developed path models to identify possible physiological traits linking childhood socioeconomic status, and poor housing standards, to two reproductive outcomes: age at first birth and total children. We explored birth weight, weight gain after birth, childhood illnesses, body mass index at age 9, age at menarche, and adult height as possible mediators. Results We found direct, negative effects of socioeconomic status (SES) and housing on age at first birth, and of housing on fertility. Although we found links between childhood disadvantage and menarche and height, neither of these were significantly correlated with either reproductive outcome. Age at first birth completely mediates the relationship between childhood adversity and total fertility, which we believe has not been empirically demonstrated before. Conclusions While there are some links between childhood adversity and child health, we find little evidence that physiological pathways, such as child health and growth, link early childhood adversity to reproductive outcomes in this relatively well‐nourished population. Am. J. Hum. Biol. 28:356–363, 2016. © 2015 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc. PMID:26407916

  9. Apomixis in plant reproduction: a novel perspective on an old dilemma.

    PubMed

    Barcaccia, Gianni; Albertini, Emidio

    2013-09-01

    Seed is one of the key factors of crop productivity. Therefore, a comprehension of the mechanisms underlying seed formation in cultivated plants is crucial for the quantitative and qualitative progress of agricultural production. In angiosperms, two pathways of reproduction through seed exist: sexual or amphimictic, and asexual or apomictic; the former is largely exploited by seed companies for breeding new varieties, whereas the latter is receiving continuously increasing attention from both scientific and industrial sectors in basic research projects. If apomixis is engineered into sexual crops in a controlled manner, its impact on agriculture will be broad and profound. In fact, apomixis will allow clonal seed production and thus enable efficient and consistent yields of high-quality seeds, fruits, and vegetables at lower costs. The development of apomixis technology is expected to have a revolutionary impact on agricultural and food production by reducing cost and breeding time, and avoiding the complications that are typical of sexual reproduction (e.g., incompatibility barriers) and vegetative propagation (e.g., viral transfer). However, the development of apomixis technology in agriculture requires a deeper knowledge of the mechanisms that regulate reproductive development in plants. This knowledge is a necessary prerequisite to understanding the genetic control of the apomictic process and its deviations from the sexual process. Our molecular understanding of apomixis will be greatly advanced when genes that are specifically or differentially expressed during embryo and embryo sac formation are discovered. In our review, we report the main findings on this subject by examining two approaches: i) analysis of the apomictic process in natural apomictic species to search for genes controlling apomixis and ii) analysis of gene mutations resembling apomixis or its components in species that normally reproduce sexually. In fact, our opinion is that a novel

  10. A review of poisonous plants that cause reproductive failure and malformations in the ruminants of Brazil.

    PubMed

    Riet-Correa, Franklin; Medeiros, Rosane M T; Schild, Ana Lucia

    2012-04-01

    The objective of this review is to provide a report on toxic plants causing reproductive problems in ruminants in Brazil. Aspidosperma pyrifolium causes abortion or stillbirth in goats, as well as most likely in sheep and cattle, in the semiarid regions of Northeastern Brazil. Intoxications by Ateleia glazioveana, Tetrapterys acutifolia and T. multiglandulosa result in abortion and neonatal mortality in cattle and sheep, and the same signs have been experimentally observed in goats. These three plants can also cause cardiac fibrosis and a nervous disease with spongiosis of the central nervous system. Other plants known to cause abortion include Enterolobium contortisiliquum, E. gummiferum, Stryphnodendron coriaceum, S. obovatum and S. fissuratum. These plants can also cause digestive signs and photosensitization. Abortions have been reported in animals intoxicated by nitrates and nitrites as well. Infertility, abortions and the birth of weak offspring have been reported in animals intoxicated by plants containing swainsonine, including Ipomoea spp., Turbina cordata and Sida carpinifolia. Trifolium subterraneum causes estrogenism in cattle. Mimosa tenuiflora and, most likely, M. ophthalmocentra cause malformations and embryonic mortality in goats, sheep and cattle in the semiarid regions of Northeastern Brazil. PMID:22147504

  11. Within- and trans-generational effects of herbivores and detritivores on plant performance and reproduction.

    PubMed

    González-Megías, Adela

    2016-01-01

    Mutualistic and antagonistic above-ground and below-ground species have the potential to be involved in strong interactions that can either weaken or strengthen their individual impacts on plants. Their impacts can also have delayed effects on a plant's progeny by altering offspring traits and survival. Few studies have explored the effect of herbivore and detritivore interactions with parent plants on offspring vital life-cycle processes, such as seedling emergence rate, seedling establishment and offspring survival. In the field, I experimentally studied the combined effects of floral herbivores (FH), root herbivores (RH) and detritivores on plant growth and reproduction of Moricandia moricandioides (Brassicaceae). In particular, I analysed the trans-generational effects of herbivores and detritivores on seed and juvenile production as well as on vital life-cycle processes (i.e. seedling emergence rates, survival). Floral herbivores strongly reduced the number of flowers, fruits, seeds and juveniles. Detritivores had an impact on plant success by increasing seed quality (% N and N : C ratio), although the effect was altered by the presence of floral and RH. I found maternal effects (trans-generational effects) of FH, RH and detritivores. Floral herbivores reduced seedling emergence and establishment. Floral and RH in combination reduced seedling emergence timing, but the effect was counteracted by detritivores. Detritivores also reduced the negative effect of FH on offspring mortality rate. This study shows that the impact of above-ground and below-ground organisms on M. moricandioides plants go beyond seed production and were evident in the probability of establishment and survival of the following generation. Trans-generational effects were induced by all three groups of interacting organisms and the net consequences for plant offspring depended on the organisms interacting with the plant. PMID:26433200

  12. Reproduction, physiology and biochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  13. Microcystin-LR impairs zebrafish reproduction by affecting oogenesis and endocrine system.

    PubMed

    Zhao, Yanyan; Xie, Liqiang; Yan, Yunjun

    2015-02-01

    Previous studies have shown that microcystins (MCs) are able to exert negative effects on the reproductive system of fish. However, few data are actually available on the effects of MC-LR on the reproductive system of female fish. In the present study, female zebrafish were exposed to 2, 10, and 50 μg L(-1) of MC-LR for 21 d, and its effects on oogenesis, sex hormones, transcription of genes on the hypothalamic-pituitary-gonad (HPG) axis, and reproduction were investigated for the first time. It was observed that egg production significantly declined at ⩾ 10 μg L(-1) MC-LR. MC-LR exposure to zebrafish increased the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) at 10 μg L(-1) level, whereas concentrations of E2, VTG and testosterone declined at 50 μg L(-1) MC-LR. The transcriptions of steroidogenic pathway gene (cyp19a, cyp19b, 17βhsd, cyp17 and hmgra) changed as well after the exposure and corresponded well with the alterations of hormone levels. A number of intra- and extra-ovarian factors, such as gnrh3, gnrhr1, fshβ, fshr, lhr, bmp15, mrpβ, ptgs2 and vtg1 which regulate oogenesis, were significantly changed with a different dose-related effect. Moreover, MC-LR exposure to female zebrafish resulted in decreased fertilization and hatching rates, and may suggest the possibility of trans-generational effects of MC-LR exposure. The results demonstrate that MC-LR could modulate endocrine function and oogenesis, eventually leading to disruption of reproductive performance in female zebrafish. These data suggest there is a risk for aquatic population living in MC polluted areas. PMID:25014902

  14. Genotypic variation in host response to infection affects parasite reproductive rate.

    PubMed

    Tavalire, Hannah F; Blouin, Michael S; Steinauer, Michelle L

    2016-02-01

    Parasite fitness is largely influenced by a variation in host response due to the host's genetic background. Here we investigated the impact of host genotype on pathogen success in the snail vector of its castrating parasite, Schistosoma mansoni. We infected five inbred lines of Biomphalaria glabrata with two infection doses and followed their growth, reproductive output and parasite production throughout the course of infection. There was no difference in resistance to infection among inbred lines, but lines varied in their responses to infection and the numbers of parasites produced. Snails did not compensate for castration by increasing their fecundity during the early phase of infection (fecundity compensation). However, some lines were able to delay parasite shedding for up to 30 weeks, thus prolonging reproduction before the onset of castration. Here we propose this strategy as a novel defense against castrating pathogens in snails. Gigantism, a predicted outcome of castration due to energy reallocation, occurred early in infection (<15 weeks) and was not universal among the snail lines. Lines that did not show gigantism were also characterised by a high parasite production rate and low survivorship, perhaps indicating energy reallocation into parasite production and costly immune defense. We observed no differences in total parasite production among lines throughout the entire course of infection, although lines differed in their parasite reproductive rate. The average rate of parasite production varied among lines from 1300 to 2450 cercariae within a single 2h shedding period, resulting in a total production of 6981-29,509 cercariae over the lifetime of a single snail. Regardless of genetic background, snail size was a strong predictor of parasite reproduction: each millimetre increase in snail size at the time of the first shed resulted in up to 3500 more cercariae over the lifetime of the snail. The results of this study provide a detailed picture of

  15. The odor of a plant metabolite affects life history traits in dietary restricted adult olive flies

    PubMed Central

    Gerofotis, Christos D.; Ioannou, Charalampos S.; Nakas, Christos T.; Papadopoulos, Nikos T.

    2016-01-01

    Food quality shapes life history traits either directly or through response of individuals to additional environmental factors, such as chemical cues. Plant extracts used as food additives modulate key life history traits; however little is known regarding such effects for olfactory chemical cues. Exploiting an interesting experimental system that involves the olive fly (Bactrocera oleae) and the plant metabolite α-pinene we asked whether exposure of adults to this compound modulates adult longevity and female reproduction in similar manner in a stressful – dietary (protein) restricted (DR) and in a relaxed- full diet (FD) feeding environment. Accordingly, we exposed males and females to the aroma of α-pinene and measured lifespan and age-specific fecundity in the above two dietary contexts. Our results demonstrate that exposure to α-pinene increased longevity in males and fecundity in females only under dietary restricted conditions. In relaxed food conditions, females exposed to α-pinene shifted high egg-laying towards younger ages compared to non-exposed ones. This is the first report demonstrating that a plant compound affects key life history traits of adult olive flies through olfaction. These effects are sex-specific and more pronounced in dietary restricted adults. Possible underlying mechanisms and the ecological significance are discussed. PMID:27339862

  16. The odor of a plant metabolite affects life history traits in dietary restricted adult olive flies.

    PubMed

    Gerofotis, Christos D; Ioannou, Charalampos S; Nakas, Christos T; Papadopoulos, Nikos T

    2016-01-01

    Food quality shapes life history traits either directly or through response of individuals to additional environmental factors, such as chemical cues. Plant extracts used as food additives modulate key life history traits; however little is known regarding such effects for olfactory chemical cues. Exploiting an interesting experimental system that involves the olive fly (Bactrocera oleae) and the plant metabolite α-pinene we asked whether exposure of adults to this compound modulates adult longevity and female reproduction in similar manner in a stressful - dietary (protein) restricted (DR) and in a relaxed- full diet (FD) feeding environment. Accordingly, we exposed males and females to the aroma of α-pinene and measured lifespan and age-specific fecundity in the above two dietary contexts. Our results demonstrate that exposure to α-pinene increased longevity in males and fecundity in females only under dietary restricted conditions. In relaxed food conditions, females exposed to α-pinene shifted high egg-laying towards younger ages compared to non-exposed ones. This is the first report demonstrating that a plant compound affects key life history traits of adult olive flies through olfaction. These effects are sex-specific and more pronounced in dietary restricted adults. Possible underlying mechanisms and the ecological significance are discussed. PMID:27339862

  17. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

    PubMed

    Geib, Jennifer C; Strange, James P; Galenj, Candace

    2015-04-01

    Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured

  18. Risk factors that affect reproductive target achievement in fertile dairy cows.

    PubMed

    Aungier, S P M; Roche, J F; Diskin, M G; Crowe, M A

    2014-01-01

    The aims of the present study were to investigate (1) the risk factors that influence the achievement of reproductive targets postpartum (pp) and (2) the key factors that influence pregnancy rate following first artificial insemination (AI) in dairy cows. Ninety-eight Holstein-Friesian pp cows were blood sampled from wk 1 to 4 pp for hematology and biochemistry. Reproductive tract health was assessed weekly by ultrasonography and vaginal mucus scoring. Body condition score (BCS), lameness score, and milk yield were assessed every 2 wk. Milk samples for progesterone assay were collected twice weekly and on d 4, 5, and 7 after AI. Risk factors associated with achieving reproductive targets depended on (1) increased metabolic activity of the liver (increased glutamate dehydrogenase at calving and increased γ-glutamyl transpeptidase in wk 4), (2) a competent immune system (increased neutrophils in wk 1; decreased α1-acid glycoprotein in wk 1, 2, and 3), (3) an endocrine system that was capable of responding by producing sufficient triiodothyronine in wk 2 and increased insulin-like growth factor I in wk 3 and 4, (4) a lower negative energy balance status (decreased nonesterified fatty acid concentration in wk 1; decreased β-hydroxybutyrate concentration in wk 2; BCS loss between calving and d 28 pp <0.5), (5) good reproductive tract health [normal uterine scan at d 45 pp; clear vaginal mucus discharge at first ovulation and at d 45 pp; resumed ovarian cyclicity by the end of the voluntary waiting period (≥ d 35 pp)], and (6) adequate diet (to ensure increased glutathione peroxidase in wk 2 and 3 and increased magnesium in wk 4). Risk factors that increased the odds of a successful first AI were previous ovulation(s) (odds ratio=3.17 per ovulation), BCS >2.5 at AI (odds ratio=3.01), and clear vaginal mucus (score=0) compared with purulent mucus (score >0) 4 d after first AI (odds ratio=2.99). In conclusion, this study identified key risk factors in the early pp

  19. Soil microbes and plant invasions—how soil-borne pathogens regulate plant populations and affect plant invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic plant invaders are a major global threat to biodiversity and ecosystem function. Here I present multiple lines of evidence suggesting that soil microbial communities affect the population growth rates of Prunus serotina in its native range and affect its invasiveness abroad. Research often ...

  20. A Single Hot Event That Does Not Affect Survival but Decreases Reproduction in the Diamondback Moth, Plutella xylostella

    PubMed Central

    Zhang, Wei; Zhao, Fei; Hoffmann, Ary A.; Ma, Chun-Sen

    2013-01-01

    Extremely hot events (usually involving a few hours at extreme high temperatures in summer) are expected to increase in frequency in temperate regions under global warming. The impact of these events is generally overlooked in insect population prediction, since they are unlikely to cause widespread mortality, however reproduction may be affected by them. In this study, we examined such stress effects in the diamondback moth, Plutella xylostella. We simulated a single extreme hot day (maximum of 40°C lasting for 3, 4 or 5 h) increasingly experienced under field conditions. This event had no detrimental effects on immediate mortality, copulation duration, mating success, longevity or lifetime fecundity, but stressed females produced 21% (after 3 or 4 h) fewer hatched eggs because of a decline in the number and hatching success of eggs laid on the first two days. These negative effects on reproduction were no longer evident in the following days. Male heat exposure led to a similar but smaller effect on fertile egg production, and exposure extended pre-mating period in both sexes. Our results indicate that a single hot day can have detrimental effects on reproduction, particularly through maternal effects on egg hatching, and thereby influence the population dynamics of diamondback moth. PMID:24116081

  1. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    NASA Astrophysics Data System (ADS)

    Migliaccio, Oriana; Castellano, Immacolata; di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-05-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system.

  2. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms.

    PubMed

    Migliaccio, Oriana; Castellano, Immacolata; Di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-01-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system. PMID:27192939

  3. Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

    PubMed Central

    Migliaccio, Oriana; Castellano, Immacolata; Di Cioccio, Davide; Tedeschi, Gabriella; Negri, Armando; Cirino, Paola; Romano, Giovanna; Zingone, Adriana; Palumbo, Anna

    2016-01-01

    The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system. PMID:27192939

  4. Pathway-based approaches for assessment of real-time exposure to an estrogenic wastewater treatment plant effluent on fathead minnow reproduction

    USGS Publications Warehouse

    Cavallin, Jenna E.; Jensen, Kathleen M.; Kahl, Michael D.; Villeneuve, Daniel L.; Lee, Kathy E.; Schroeder, Anthony L.; Mayasich, Joe; Eid, Evan P.; Nelson, Krysta R.; Milsk, Rebecca Y.; Blackwell, Brett R.; Berninger, Jason P.; LaLone, Carlie A.; Blanskma, Chad; Jicha, Terri M.; Elonen, Colleen M.; Johnson, Rodney C.; Ankley, Gerald T.

    2016-01-01

    Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds, such as estrogens, which can affect the hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined reproductive effects in fathead minnows exposed for 21 d to a historically estrogenic WWTP effluent. Fathead minnow breeding pairs were held in control water or 1 of 3 effluent concentrations (5%, 20%, and 100%) in a novel onsite, flow-through system providing real-time exposure. The authors examined molecular and biochemical endpoints representing key events along adverse outcome pathways linking estrogen receptor activation and other molecular initiating events to reproductive impairment. In addition, the authors used chemical analysis of the effluent to construct a chemical-gene interaction network to aid in targeted gene expression analyses and identifying potentially impacted biological pathways. Cumulative fecundity was significantly reduced in fish exposed to 100% effluent but increased in those exposed to 20% effluent, the approximate dilution factor in the receiving waters. Plasma vitellogenin concentrations in males increased in a dose-dependent manner with effluent concentration; however, male fertility was not impacted. Although in vitro analyses, analytical chemistry, and biomarker responses confirmed the effluent was estrogenic, estrogen receptor agonists were unlikely the primary driver of impaired reproduction. The results provide insights into the significance of pathway-based effects with regard to predicting adverse reproductive outcomes.

  5. Direct effects of energy-related air pollutants on plant sexual reproduction. Progress report, February 1, 1981-January 31, 1982

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1982-10-07

    Direct effects of SO/sub 2/ and NO/sub 2/ on plant sexual reproduction were studied including essential botanical research into modes of anthesis, pollination, pollen germination and pollen tube growth. Much of the present scientific knowledge of the direct in vivo effects of the major air pollutants, SO/sub 2/ and NO/sub 2/, on plant sexual reproduction is a direct result of studies accomplished under this DOE contract. It is our intention to carry this research forward to include similar assessment of a third major air pollutant, ozone.

  6. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response.

    PubMed

    Rangel, Juliana; Böröczky, Katalin; Schal, Coby; Tarpy, David R

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of "high-quality" queens (i.e., raised from first instar worker larvae; more queen-like) and "low-quality" queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone ("QMP") components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the "queen-specific" developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting that other external

  7. Honey Bee (Apis mellifera) Queen Reproductive Potential Affects Queen Mandibular Gland Pheromone Composition and Worker Retinue Response

    PubMed Central

    Böröczky, Katalin; Schal, Coby; Tarpy, David R.

    2016-01-01

    Reproductive division of labor is one of the defining traits of honey bees (Apis mellifera), with non-reproductive tasks being performed by workers while a single queen normally monopolizes reproduction. The decentralized organization of a honey bee colony is maintained in large part by a bouquet of queen-produced pheromones, the distribution of which is facilitated by contact among workers throughout the hive. Previous studies have shown that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures of reproductive potential compared to queens raised from older worker larvae. We investigated differences in the chemical composition of the mandibular glands and attractiveness to workers of “high-quality” queens (i.e., raised from first instar worker larvae; more queen-like) and “low-quality” queens (i.e., raised from third instar worker larvae; more worker-like). We characterized the chemical profiles of the mandibular glands of high-quality queens and low-quality queens using GC-MS and used the worker retinue response as a measure of the attractiveness to workers of high-quality queens vs. low-quality queens. We found that queen quality affected the chemical profiles of mandibular gland contents differently across years, showing significant differences in the production of the queen mandibular pheromone (“QMP”) components HVA and 9-HDA in 2010, but no significant differences of any glandular compound in 2012. We also found that workers were significantly more attracted to high-quality queens than to low-quality queens in 2012, possibly because of increased attractiveness of their mandibular gland chemical profiles. Our results indicate that the age at which honey bee larvae enter the “queen-specific” developmental pathway influences the chemical composition of queen mandibular glands and worker behavior. However, these changes are not consistent across years, suggesting

  8. Host-Parasite Interactions from the Inside: Plant Reproductive Ontogeny Drives Specialization in Parasitic Insects

    PubMed Central

    Boivin, Thomas; Gidoin, Cindy; von Aderkas, Patrick; Safrana, Jonathan; Candau, Jean-Noël; Chalon, Alain; Sondo, Marion; El Maâtaoui, Mohamed

    2015-01-01

    Host plant interactions are likely key drivers of evolutionary processes involved in the diversification of phytophagous insects. Granivory has received substantial attention for its crucial role in shaping the interaction between plants and their seed parasites, but fine-scale mechanisms explaining the role of host plant reproductive biology on specialization of seed parasites remain poorly described. In a comparative approach using plant histological techniques, we tested the hypotheses that different seed parasite species synchronize their life cycles to specific stages in seed development, and that the stage they target depends on major differences in seed development programs. In a pinaceous system, seed storage products are initiated before ovule fertilization and the wasps target the ovule’s nucellus during megagametogenesis, a stage at which larvae may benefit from the by-products derived from both secreting cells and dying nucellar cells. In a cupressaceous system, oviposition activity peaks later, during embryogenesis, and the wasps target the ovule’s megagametophyte where larvae may benefit from cell disintegration during embryogenesis. Our cytohistological approach shows for the first time how, despite divergent oviposition targets, different parasite species share a common strategy that consists of first competing for nutrients with developing plant structures, and then consuming these developed structures to complete their development. Our results support the prediction that seed developmental program is an axis for specialization in seed parasites, and that it could be an important parameter in models of their ecological and taxonomic divergence. This study provides the basis for further investigating the possibility of the link between plant ontogeny and pre-dispersal seed parasitism. PMID:26441311

  9. Food availability affects Osmia pumila (Hymenoptera: Megachilidae) foraging, reproduction, and brood parasitism.

    PubMed

    Goodell, Karen

    2003-03-01

    Food limitation can reduce reproductive success directly, as well as indirectly, if foraging imposes a risk of predation or parasitism. The solitary bee Osmia pumila suffers brood parasitism by the cleptoparasitic wasp Sapyga centrata, which enters the host nest to oviposit while the female bee is away. I studied foraging and reproduction of O. pumila nesting within cages stocked with rich or sparse floral resources, and the presence or absence of S. centrata to test (1) the response of nesting female O. pumila to food shortages, (2) the response of nesting female O. pumila to the presence of parasites, and (3) whether brood produced under scarce resources are more likely to be parasitized by S. centrata. The rate of brood cell production was significantly lower in cages with sparse floral resources, although females in sparse cages did not produce significantly fewer brood cells overall. Sapyga centrata did not influence the rate of brood cell production, but females exposed to the cleptoparasites had marginally significantly lower reproductive output. Nests in parasite cages had significantly fewer brood cells than those in parasite free cages. The mean duration of foraging bouts made by female O. pumila in sparse cages was not significantly longer than that in rich cages. O. pumila spent less time in the nest between pollen and nectar foraging bouts in sparse cages with S. centrata than those in other cages suggesting that these individuals made more frequent food foraging trips. Despite the weak effects of parasites and bloom density on foraging behavior, O. pumila brood cells experienced a 5-fold higher probability of parasitism by S. centrata in cages with sparse bloom than in those with rich bloom [corrected]. These results support the hypothesis that indirect effects of food scarcity increase O. pumila susceptibility to brood parasitism, although the exact mechanism is not entirely clear yet. PMID:12647124

  10. Reproductive value in a complex life cycle: heat tolerance of the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Zani, P A; Cohnstaedt, L W; Corbin, D; Bradshaw, W E; Holzapfel, C M

    2005-01-01

    Because mortality accumulates with age, Fisher proposed that the strength of selection acting on survival should increase from birth up to the age of first reproduction. Hamilton later theorized that the strength of selection acting on survival should not change from birth to age at first reproduction. As organisms in nature do not live in uniform environments but, rather, experience periodic stress, we hypothesized that resistance to environmental stress should increase (Fisher) or remain constant (Hamilton) from birth to age at first reproduction. Using the pitcher-plant mosquito, Wyeomyia smithii, we imposed heat stress by simulating the passage of a warm-weather front at different pre-adult and adult stages. Contrary to either Fisher or Hamilton, stress tolerance declined from embryos to larvae to pupae to adults. Consequently, reproductive value appears to have been of little consequence in the evolution of stage-specific tolerance of heat stress in W. smithii. PMID:15669965

  11. [Diversity of Coccinellidae (Coleoptera) using aromatic plants (Apiaceae) as survival and reproduction sites in agroecological system].

    PubMed

    Lixa, Alice T; Campos, Juliana M; Resende, André L S; Silva, Joice C; Almeida, Maxwell M T B; Aguiar-Menezes, Elen L

    2010-01-01

    Studies show that Apiaceae may provide concentrated vital resources for predator insects, stimulating their abundance, diversity and persistence in agricultural systems, thereby increasing their efficiency as biological control agents. Among the predatory insects, Coccinellidae (Coleoptera) on many different species both as larvae and adults, complementing their diet with pollen and/or nectar. This study aimed to determine the diversity and relative abundance of Coccinellidae species visiting plants of Anethum graveolens (dill), Coriandrum sativum (coriander) and Foeniculum vulgare (sweet fennel) (all Apiaceae), particularly in their blooming seasons, and to evaluate the potential of these aromatic species for providing the resources for survivorship and reproduction of coccinelids. Coccinellids were collected by removal of samplings from September to October, 2007. Besides one unidentified species of Chilocorinae, five species of Coccinellinae were collected: Coleomegilla maculata DeGeer, Coleomegilla quadrifasciata (Schönherr), Cycloneda sanguinea (L.), Eriopis connexa (Germar) and Hippodamia convergens Guérin-Meneville. Dill provided a significant increase in the abundance of coccinellids as compared to coriander and sweet fennel. These aromatic species were used by coccinellids as survival and reproduction sites, providing food resources (pollen and/or prey), shelter for larvae, pupae and adults, and mating and oviposition sites as well. PMID:20676507

  12. Factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the outer banks of North Carolina

    USGS Publications Warehouse

    Schulte, Shiloh A.; Simons, Theodore R.

    2015-01-01

    We used an information-theoretic approach to assess the factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the Outer Banks of North Carolina. We evaluated survival with respect to nesting island, year, time of season, brood age, distance to tide (m), presence of off-road vehicles and proximity of foraging habitat. The daily nest survival (mean 0.981, standard error [SE] 0.002) was affected by year and island, and declined over the nesting season. Mammals were responsible for 54% of identified nest failures. Daily brood survival (mean 0.981, SE 0.002) varied by island and increased non-linearly with age, with highest mortality in the seven days after hatching. Model results indicate direct access to foraging sites has a positive effect on brood survival, whereas presence of off-road vehicles has a negative effect. We studied chick behavior and survival using radio telemetry and direct observation and found that vehicles caused mortality and affected behavior and resource use by oystercatcher chicks. We identified the source of mortality for 37 radio-tagged chicks. Six (16%) were killed by vehicles, 21 (57%) by predators, and 10 (27%) by exposure and starvation. From 1995 to 2008, 25 additional oystercatcher chicks were found dead, 13 (52%) killed by vehicles. Chicks on beaches closed to vehicles used beach and intertidal zones more frequently than chicks on beaches open to vehicles. Chick predators included Great Horned Owls Bubo virginianus, Fish Crows Corvus ossifragus, cats Felis catus, mink Mustela vison, raccoons Procyon lotor, and ghost crabs Ocypode albicans. The factors affecting reproductive success differed between the incubation and chick-rearing stages.  Management actions that influence chick survival will have a larger effect on total productivity than actions affecting nest survival.

  13. Sodium fluoride and sulfur dioxide affected male reproduction by disturbing blood-testis barrier in mice.

    PubMed

    Zhang, Jianhai; Li, Zhihui; Qie, Mingli; Zheng, Ruibo; Shetty, Jagathpala; Wang, Jundong

    2016-08-01

    Fluoride and sulfur dioxide (SO2), two well-known environmental toxicants, have been implicated to have adverse effects on male reproductive health in humans and animals. The objective of this study to investigate if the BTB is one of the pathways that lead to reproductive toxicity of sodium fluoride and sulfur dioxide alone or in combination, in view of the key role of blood testis barrier (BTB) in testis. The results showed that a marked decrease in sperm quality, and altered morphology and ultrastructure of BTB in testis of mice exposure to fluoride (100 mg NaF/L in drinking water) or/and sulfur dioxide (28 mg SO2/m(3), 3 h/day). Meanwhile, the mRNA expression levels of some vital BTB-associated proteins, including occluding, claudin-11, ZO-1, Ncadherin, α-catenin, and connexin-43 were all strikingly reduced after NaF exposure, although only the reduction of DSG-2 was statistically significant in all treatment groups. Moreover, the proteins expressions also decreased significantly in claudin-11, N-cadherin, α-catenin, connexin-43 and desmoglein-2 in mice treated with fluoride and/or SO2. These changes in BTB structure and constitutive proteins may therefore be connected with the low sperm quality in these mice. The role of fluoride should deserves more attention in this process. PMID:27237588

  14. Alloparenting experience affects future parental behavior and reproductive success in prairie voles (Microtus ochrogaster).

    PubMed

    Stone, Anita Iyengar; Mathieu, Denise; Griffin, Luana; Bales, Karen Lisa

    2010-01-01

    Various hypotheses have been proposed to explain the function of alloparental behavior in cooperatively breeding species. We examined whether alloparental experience as juveniles enhanced later parental care and reproductive success in the prairie vole (Microtus ochrogaster), a cooperatively breeding rodent. Juveniles cared for one litter of siblings (1EX), two litters of siblings (2EX) or no siblings (0EX). As adults, these individuals were mated to other 0EX, 1EX or 2EX voles, yielding seven different pair combinations, and we recorded measures of parental behaviors, reproductive success, and pup development. As juveniles, individuals caring for siblings for the first time were more alloparental; and as adults, 0EX females paired with 0EX males spent more time in the nest with their pups. Taken together, these results suggest that inexperienced animals spend more time in infant care. As parents, 1EX males spent more time licking their pups than 2EX and 0EX males. Pups with either a 1EX or 2EX parent gained weight faster than pups with 0EX parents during certain developmental periods. While inexperienced animals may spend more time in pup care, long-term benefits of alloparenting may become apparent in the display of certain, particularly important parental behaviors such as licking pups, and in faster weight gain of offspring. PMID:19732810

  15. Vegetative and reproductive innovations of early land plants: implications for a unified phylogeny.

    PubMed Central

    Renzaglia, K S; Duff RJT; Nickrent, D L; Garbary, D J

    2000-01-01

    As the oldest extant lineages of land plants, bryophytes provide a living laboratory in which to evaluate morphological adaptations associated with early land existence. In this paper we examine reproductive and structural innovations in the gametophyte and sporophyte generations of hornworts, liverworts, mosses and basal pteridophytes. Reproductive features relating to spermatogenesis and the architecture of motile male gametes are overviewed and evaluated from an evolutionary perspective. Phylogenetic analyses of a data set derived from spermatogenesis and one derived from comprehensive morphogenetic data are compared with a molecular analysis of nuclear and mitochondrial small subunit rDNA sequences. Although relatively small because of a reliance on water for sexual reproduction, gametophytes of bryophytes are the most elaborate of those produced by any land plant. Phenotypic variability in gametophytic habit ranges from leafy to thalloid forms with the greatest diversity exhibited by hepatics. Appendages, including leaves, slime papillae and hairs, predominate in liverworts and mosses, while hornwort gametophytes are strictly thalloid with no organized external structures. Internalization of reproductive and vegetative structures within mucilage-filled spaces is an adaptive strategy exhibited by hornworts. The formative stages of gametangial development are similar in the three bryophyte groups, with the exception that in mosses apical growth is intercalated into early organogenesis, a feature echoed in moss sporophyte ontogeny. A monosporangiate, unbranched sporophyte typifies bryophytes, but developmental and structural innovations suggest the three bryophyte groups diverged prior to elaboration of this generation. Sporophyte morphogenesis in hornworts involves non-synchronized sporogenesis and the continued elongation of the single sporangium, features unique among archegoniates. In hepatics, elongation of the sporophyte seta and archegoniophore is rapid

  16. Vegetative and reproductive innovations of early land plants: implications for a unified phylogeny.

    PubMed

    Renzaglia, K S; Duff RJT; Nickrent, D L; Garbary, D J

    2000-06-29

    As the oldest extant lineages of land plants, bryophytes provide a living laboratory in which to evaluate morphological adaptations associated with early land existence. In this paper we examine reproductive and structural innovations in the gametophyte and sporophyte generations of hornworts, liverworts, mosses and basal pteridophytes. Reproductive features relating to spermatogenesis and the architecture of motile male gametes are overviewed and evaluated from an evolutionary perspective. Phylogenetic analyses of a data set derived from spermatogenesis and one derived from comprehensive morphogenetic data are compared with a molecular analysis of nuclear and mitochondrial small subunit rDNA sequences. Although relatively small because of a reliance on water for sexual reproduction, gametophytes of bryophytes are the most elaborate of those produced by any land plant. Phenotypic variability in gametophytic habit ranges from leafy to thalloid forms with the greatest diversity exhibited by hepatics. Appendages, including leaves, slime papillae and hairs, predominate in liverworts and mosses, while hornwort gametophytes are strictly thalloid with no organized external structures. Internalization of reproductive and vegetative structures within mucilage-filled spaces is an adaptive strategy exhibited by hornworts. The formative stages of gametangial development are similar in the three bryophyte groups, with the exception that in mosses apical growth is intercalated into early organogenesis, a feature echoed in moss sporophyte ontogeny. A monosporangiate, unbranched sporophyte typifies bryophytes, but developmental and structural innovations suggest the three bryophyte groups diverged prior to elaboration of this generation. Sporophyte morphogenesis in hornworts involves non-synchronized sporogenesis and the continued elongation of the single sporangium, features unique among archegoniates. In hepatics, elongation of the sporophyte seta and archegoniophore is rapid

  17. Reproductive biology of the biofuel plant Jatropha curcas in its center of origin.

    PubMed

    Rincón-Rabanales, Manuel; Vargas-López, Laura I; Adriano-Anaya, Lourdes; Vázquez-Ovando, Alfredo; Salvador-Figueroa, Miguel; Ovando-Medina, Isidro

    2016-01-01

    In this work, we studied the main characteristics of flowering, reproductive system and diversity of pollinators for the biofuel plant Jatropha curcas (L.) in a site of tropical southeastern Mexico, within its center of origin. The plants were monoecious with inflorescences of unisexual flowers. The male flowers produced from 3062-5016 pollen grains (266-647 per anther). The plants produced fruits with both geitonogamy and xenogamy, although insect pollination significantly increased the number and quality of fruits. A high diversity of flower visiting insects (36 species) was found, of which nine were classified as efficient pollinators. The native stingless bees Scaptotrigona mexicana (Guérin-Meneville) and Trigona (Tetragonisca) angustula (Latreille) were the most frequent visitors and their presence coincided with the hours when the stigma was receptive. It is noteworthy that the female flowers open before the male flowers, favoring xenogamy, which may explain the high genetic variability reported in J. curcas for this region of the world. PMID:26989640

  18. Reproductive biology of the biofuel plant Jatropha curcas in its center of origin

    PubMed Central

    Rincón-Rabanales, Manuel; Vargas-López, Laura I.; Adriano-Anaya, Lourdes; Salvador-Figueroa, Miguel

    2016-01-01

    In this work, we studied the main characteristics of flowering, reproductive system and diversity of pollinators for the biofuel plant Jatropha curcas (L.) in a site of tropical southeastern Mexico, within its center of origin. The plants were monoecious with inflorescences of unisexual flowers. The male flowers produced from 3062–5016 pollen grains (266–647 per anther). The plants produced fruits with both geitonogamy and xenogamy, although insect pollination significantly increased the number and quality of fruits. A high diversity of flower visiting insects (36 species) was found, of which nine were classified as efficient pollinators. The native stingless bees Scaptotrigona mexicana (Guérin-Meneville) and Trigona (Tetragonisca) angustula (Latreille) were the most frequent visitors and their presence coincided with the hours when the stigma was receptive. It is noteworthy that the female flowers open before the male flowers, favoring xenogamy, which may explain the high genetic variability reported in J. curcas for this region of the world. PMID:26989640

  19. DESTAF: a database of text-mined associations for reproductive toxins potentially affecting human fertility.

    PubMed

    Dawe, Adam S; Radovanovic, Aleksandar; Kaur, Mandeep; Sagar, Sunil; Seshadri, Sundararajan V; Schaefer, Ulf; Kamau, Allan A; Christoffels, Alan; Bajic, Vladimir B

    2012-01-01

    The Dragon Exploration System for Toxicants and Fertility (DESTAF) is a publicly available resource which enables researchers to efficiently explore both known and potentially novel information and associations in the field of reproductive toxicology. To create DESTAF we used data from the literature (including over 10500 PubMed abstracts), several publicly available biomedical repositories, and specialized, curated dictionaries. DESTAF has an interface designed to facilitate rapid assessment of the key associations between relevant concepts, allowing for a more in-depth exploration of information based on different gene/protein-, enzyme/metabolite-, toxin/chemical-, disease- or anatomically centric perspectives. As a special feature, DESTAF allows for the creation and initial testing of potentially new association hypotheses that suggest links between biological entities identified through the database. DESTAF, along with a PDF manual, can be found at http://cbrc.kaust.edu.sa/destaf. It is free to academic and non-commercial users and will be updated quarterly. PMID:22198179

  20. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees.

    PubMed

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  1. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees

    PubMed Central

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C.; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  2. Gonadal steroids and affective symptoms during in vitro fertilization: implication for reproductive mood disorders.

    PubMed

    Bloch, Miki; Aharonov, Inbar; Ben Avi, Irit; Schreiber, Shaul; Amit, Ami; Weizman, Abraham; Azem, Foad

    2011-07-01

    Gonadal steroids (GSs) have been associated with the onset of a number of reproductive-related mood disorders in women, in which fluctuating or unstable hormonal levels are postulated to act as the trigger for the destabilization of mood. There is, however, rather limited direct clinical evidence that can link rapidly changing GS levels with the induction of mood symptoms. We aimed to study the effect of controlled and rapid GS fluctuations on mood in an in vivo model. Women undergoing in vitro fertilization (n=108) were assessed for depression and anxiety levels on 3 time points: during a low estradiol and progesterone baseline, during a gonadotropin stimulated estradiol-dominant phase, and after embryo transfer, during a progesterone-dominant low estrogen phase. Plasma levels for estrogen and progesterone were drawn on these time points. Symptoms of depression and anxiety significantly increased from baseline to the high estradiol levels but were not correlated with estrogen. The sharp drop from high estradiol levels at the estradiol-dominant phase to low levels at the progesterone-dominant phase was significantly correlated with rising depression scores. The rise in progesterone levels from low levels at the estradiol-dominant phase to high levels at the progesterone-dominant phase was significantly and inversely correlated with depression scores. This study suggests that the mechanism underlying the role of estrogen in reproductive-related mood disorders involves an abrupt and precipitous drop in its plasma level that can precipitate negative mood states. This finding has implications on the treatment of GS-related mood disorders. PMID:21106297

  3. Sexual and apomictic plant reproduction in the genomics era: exploring the mechanisms potentially useful in crop plants.

    PubMed

    Dwivedi, Sangam L; Perotti, Enrico; Upadhyaya, Hari D; Ortiz, Rodomiro

    2010-12-01

    Arabidopsis, Mimulus and tomato have emerged as model plants in researching genetic and molecular basis of differences in mating systems. Variations in floral traits and loss of self-incompatibility have been associated with mating system differences in crops. Genomics research has advanced considerably, both in model and crop plants, which may provide opportunities to modify breeding systems as evidenced in Arabidopsis and tomato. Mating system, however, not recombination per se, has greater effect on the level of polymorphism. Generating targeted recombination remains one of the most important factors for crop genetic enhancement. Asexual reproduction through seeds or apomixis, by producing maternal clones, presents a tremendous potential for agriculture. Although believed to be under simple genetic control, recent research has revealed that apomixis results as a consequence of the deregulation of the timing of sexual events rather than being the product of specific apomixis genes. Further, forward genetic studies in Arabidopsis have permitted the isolation of novel genes reported to control meiosis I and II entry. Mutations in these genes trigger the production of unreduced or apomeiotic megagametes and are an important step toward understanding and engineering apomixis. PMID:20509033

  4. REPRODUCTIVE DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Throughout history, humans have celebrated the beauty and fertility of flowering plants. In addition to their aesthetic appeal, flowers contain the reproductive organs of the plant and are therefore essential for sexual propagation of plant life. Our dependence on flowering is illustrated by the die...

  5. Key Factors Affecting Reproductive Success of Thoroughbred Mares and Stallions on a Commercial Stud Farm.

    PubMed

    Lane, E A; Bijnen, Mlj; Osborne, M; More, S J; Henderson, Isf; Duffy, P; Crowe, M A

    2016-04-01

    To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4-15 years) had bred 2385 mares (mean age 9.4 years; range 3-24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk-in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post-partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting. PMID:26815482

  6. A microsystem-based assay for studying pollen tube guidance in plant reproduction

    NASA Astrophysics Data System (ADS)

    Yetisen, A. K.; Jiang, L.; Cooper, J. R.; Qin, Y.; Palanivelu, R.; Zohar, Y.

    2011-05-01

    We present a novel microsystem-based assay to assess and quantify pollen tube behavior in response to pistil tissues. During plant reproduction, signals from female tissues (pistils) guide the sperm-carrying pollen tube to the egg cell to achieve fertilization and initiate seed development. Existing pollen tube guidance bioassays are performed in an isotropically diffusive environment (for example, a semi in vivo assay in petri dishes) instead of anisotropically diffusive conditions required to characterize guidance signal gradients. Lack of a sensitive pollen tube guidance bioassay has therefore compounded the difficulties of identifying and characterizing the guidance signals that are likely produced in minute quantities by the ovules. We therefore developed a novel microsystem-based assay that mimics the in vivo micro-environment of ovule fertilization by pollen tubes in the model research plant Arabidopsis thaliana. In this microdevice, the pollen tube growth rate, length and ovule targeting frequencies were similar to those obtained using a semi in vivo plate assay. As a direct measure of the microdevice's utility in monitoring pollen tube guidance, we demonstrated that in this device, pollen tubes preferentially enter chambers with unfertilized ovules, suggesting that the pollen tubes sense the concentration gradient and respond to the chemoattractants secreted by unfertilized ovules.

  7. Maternally transferred dioxin-like compounds can affect the reproductive success of European eel.

    PubMed

    Foekema, Edwin M; Kotterman, Michiel; de Vries, Pepijn; Murk, Albertinka J

    2016-01-01

    Reported concentrations of dioxin-like compounds accumulated in the European eel (Anguilla anguilla) were used to perform a risk assessment for eel larval survival, taking into account a modeled amplification of tissue concentrations with a factor of 1.33 during spawning migration. The calculated concentrations of dioxin-like compounds finally deposited in the eggs were compared with the internal effect concentrations for survival of early life stages of the European eel; these concentrations, by lack of experimental data, were estimated from a sensitivity distribution based on literature data by assuming that eel larvae are among the 10% most sensitive teleost fish species. Given concentrations of dioxin-like contaminants and assuming a relatively high sensitivity, it can be expected that larvae from eggs produced by eel from highly contaminated locations in Europe will experience increased mortality as a result of maternally transferred dioxin-like contaminants. As historical persistent organic pollutant concentrations in eel tissue were higher, this impact must have been stronger in the past. Potential effects of other compounds or effects on the migration, condition, and fertility of the parental animals were not taken into account. It is important to further study the overall impact of contaminants on the reproductive success of the European eel as this may have been underestimated until now. PMID:26223357

  8. Nanoplastic affects growth of S. obliquus and reproduction of D. magna.

    PubMed

    Besseling, Ellen; Wang, Bo; Lürling, Miquel; Koelmans, Albert A

    2014-10-21

    The amount of nano- and microplastic in the aquatic environment rises due to the industrial production of plastic and the degradation of plastic into smaller particles. Concerns have been raised about their incorporation into food webs. Little is known about the fate and effects of nanoplastic, especially for the freshwater environment. In this study, effects of nano-polystyrene (nano-PS) on the growth and photosynthesis of the green alga Scenedesmus obliquus and the growth, mortality, neonate production, and malformations of the zooplankter Daphnia magna were assessed. Nano-PS reduced population growth and reduced chlorophyll concentrations in the algae. Exposed Daphnia showed a reduced body size and severe alterations in reproduction. Numbers and body size of neonates were lower, while the number of neonate malformations among neonates rose to 68% of the individuals. These effects of nano-PS were observed between 0.22 and 103 mg nano-PS/L. Malformations occurred from 30 mg of nano-PS/L onward. Such plastic concentrations are much higher than presently reported for marine waters as well as freshwater, but may eventually occur in sediment pore waters. As far as we know, these results are the first to show that direct life history shifts in algae and Daphnia populations may occur as a result of exposure to nanoplastic. PMID:25268330

  9. An investigation into the factors affecting the natural reproduction of Opsaridium peringueyi

    NASA Astrophysics Data System (ADS)

    Moyo, N. A. G.

    An endangered freshwater fish, Opsaridium peringueyi, was studied from January, 2009 to December, 2009. The analysis of the environmental conditions indicated that the fish is found in streams with moderate to fast flow, high oxygen levels, a depth greater than 0.6 m and temperatures between 10 and 24 °C. O. peringueyi is sexually dimorphic with males growing at a faster rate and attaining a larger size than females. The breeding biology of this species was investigated in glass aquarium tanks. The spawning behaviour is described for the first time. The breeding colour of the male is deep red on the operculum, ventral part, caudal and ventral fins. The breeding colour in the female is the same as the male except the red colour is lighter. The breeding of O. peringueyi is a four stage process which begins with the appearance of breeding colour culminating in the laying of eggs after courtship. Temperature, flow-rate, conductivity and substrate were identified as the environmental cues important in the reproduction of this species. All these factors had a significant effect on the breeding activity of O. peringueyi. The possible effect of climate change on O. peringueyi is discussed.

  10. The effects of inbreeding, genetic dissimilarity and phenotype on male reproductive success in a dioecious plant

    PubMed Central

    Austerlitz, Frédéric; Gleiser, Gabriela; Teixeira, Sara; Bernasconi, Giorgina

    2012-01-01

    Pollen fate can strongly affect the genetic structure of populations with restricted gene flow and significant inbreeding risk. We established an experimental population of inbred and outbred Silene latifolia plants to evaluate the effects of (i) inbreeding depression, (ii) phenotypic variation and (iii) relatedness between mates on male fitness under natural pollination. Paternity analysis revealed that outbred males sired significantly more offspring than inbred males. Independently of the effects of inbreeding, male fitness depended on several male traits, including a sexually dimorphic (flower number) and a gametophytic trait (in vitro pollen germination rate). In addition, full-sib matings were less frequent than randomly expected. Thus, inbreeding, phenotype and genetic dissimilarity simultaneously affect male fitness in this animal-pollinated plant. While inbreeding depression might threaten population persistence, the deficiency of effective matings between sibs and the higher fitness of outbred males will reduce its occurrence and counter genetic erosion. PMID:21561968

  11. Developmental methoxychlor exposure affects multiple reproductive parameters and ovarian folliculogenesis and gene expression in adult rats

    SciTech Connect

    Armenti, AnnMarie E.; Zama, Aparna Mahakali; Passantino, Lisa; Uzumcu, Mehmet

    2008-12-01

    Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 {mu}g/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P < 0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P < 0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P < 0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor {beta} was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P < 0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P < 0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis.

  12. The binary mixtures of megestrol acetate and 17α-ethynylestradiol adversely affect zebrafish reproduction.

    PubMed

    Hua, Jianghuan; Han, Jian; Wang, Xianfeng; Guo, Yongyong; Zhou, Bingsheng

    2016-06-01

    Synthetic progesterones and estrogens are broadly used bioactive pharmaceutical agents and have been detected in aquatic environments. In the present study, we investigated the combined reproductive effects of megestrol acetate (MTA) and 17α-ethinylestradiol (EE2) on zebrafish. Adult zebrafish were exposed to MTA (33, 100 or 333 ng/L), EE2 (10 ng/L) or a mixture of both (MTA + EE2: 33 + 10, 100 + 10 or 333 + 10 ng/L) for 21 days. Results demonstrated that egg production was significantly reduced by exposure to 10 ng/L EE2, but not MTA. However, a combined exposure to MTA and EE2 caused further reduction of fish fecundity compared to EE2 exposure alone, suggesting an additive effect on egg production when EE2 is supplemented with MTA. Plasma concentrations of 17β-estradiol and testosterone in the females and 11-ketotestosterone in the males were significantly decreased in the groups exposed to EE2 or MTA alone compared with the solvent control, and the plasma concentrations of the three hormones were further reduced in the co-exposure groups relative to the MTA exposure group, but not the EE2 exposure group. These data indicate that the inhibitory effects on plasma concentrations in the co-exposures were predominantly caused by EE2. Furthermore, exposure to MTA and EE2 (alone or in combination) led to histological alterations in the ovaries (decreased vitellogenic/mature oocytes), but not in the testes. This study has important implications for environmental risk assessment of synthetic hormones that are concurrently present in aquatic systems. PMID:27038209

  13. Developmental Methoxychlor Exposure Affects Multiple Reproductive Parameters and Ovarian: Folliculogenesis and Gene Expression in Adult Rats

    PubMed Central

    Armenti, AnnMarie E.; Zama, Aparna Mahakali; Passantino, Lisa; Uzumcu, Mehmet

    2008-01-01

    Methoxychlor (MXC) is an organochlorine pesticide with estrogenic, anti-estrogenic, and anti-androgenic properties. To investigate whether transient developmental exposure to MXC could cause adult ovarian dysfunction, we exposed Fischer rats to 20 μg/kg/day (low dose; environmentally relevant dose) or 100 mg/kg/day (high dose) MXC between 19 days post-coitum and postnatal day 7. Multiple reproductive parameters, serum hormone levels, and ovarian morphology and molecular markers were examined from prepubertal through adult stages. High dose MXC accelerated pubertal onset and first estrus, reduced litter size, and increased irregular cyclicity (P < 0.05). MXC reduced superovulatory response to exogenous gonadotropins in prepubertal females (P < 0.05). Rats exposed to high dose MXC had increasing irregular estrous cyclicity beginning at 4 months of age, with all animals showing abnormal cycles by 6 months. High dose MXC reduced serum progesterone, but increased luteinizing hormone (LH). Follicular composition analysis revealed an increase in the percentage of preantral and early antral follicles and a reduction in the percentage of corpora lutea in high dose MXC-treated ovaries (P < 0.05). Immunohistochemical staining and quantification of the staining intensity showed that estrogen receptor β was reduced by high dose MXC while anti-Mullerian hormone was upregulated by both low- and high dose MXC in preantral and early antral follicles (P < 0.05). High dose MXC significantly reduced LH receptor expression in large antral follicles (P < 0.01), and down-regulated cytochrome P450 side-chain cleavage. These results demonstrated that developmental MXC exposure results in reduced ovulation and fertility and premature aging, possibly by altering ovarian gene expression and folliculogenesis. PMID:18848953

  14. Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

    USGS Publications Warehouse

    Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

    2004-01-01

    At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

  15. Sublethal effects of antibiosis resistance on the reproductive biology of two spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria spp.

    PubMed

    Sotelo, Paola A; Miller, María F; Cardona, Cesar; Miles, John W; Sotelo, Guillermo; Montoya, James

    2008-04-01

    Several greenhouse experiments were used to measure how high levels of antibiosis resistance to nymphs in two interspecific Brachiaria (brachiariagrass) hybrids affect life history parameters of the spittlebugs Aeneolamia varia (F.) and Zulia carbonaria (Lallemand), two of the most important spittlebug (Hemiptera: Cercopidae) species affecting Brachiaria production in Colombia. The A. varia-resistant hybrid CIAT 36062, the Z. carbonaria-resistant hybrid SX01NO/0102, and the susceptible accession CIAT 0654 were used to compare the effect of all possible combinations of food sources for nymphs and adults. Calculation of growth indexes showed a significant impact of antibiosis resistance on the biology of immature stages of both species. Median survival times of adults feeding on resistant genotypes did not differ from those recorded on the susceptible genotype, suggesting that factors responsible for high mortality of nymphs in the resistant hybrids did not affect adult survival. Rearing nymphs of A. varia on CIAT 36062 and of Z. carbonaria on SX01NO/0102 had deleterious sublethal effects on the reproductive biology of resulting adult females. It is concluded that high nymphal mortality and subsequent sublethal effects of nymphal antibiosis on adults should have a major impact on the demography of the two spittlebug species studied. PMID:18459425

  16. Nectar secretion dynamic links pollinator behavior to consequences for plant reproductive success in the ornithophilous mistletoe Psittacanthus robustus.

    PubMed

    Guerra, T J; Galetto, L; Silva, W R

    2014-09-01

    The mistletoe Psittacanthus robustus was studied as a model to link flower phenology and nectar secretion strategy to pollinator behaviour and the reproductive consequences for the plant. The bright-coloured flowers presented diurnal anthesis, opened asynchronously throughout the rainy season and produced copious dilute nectar as the main reward for pollinators. Most nectar was secreted just after flower opening, with little sugar replenishment after experimental removals. During the second day of anthesis in bagged flowers, the flowers quickly reabsorbed the offered nectar. Low values of nectar standing crop recorded in open flowers can be linked with high visitation rates by bird pollinators. Eight hummingbirds and two passerines were observed as potential pollinators. The most frequent flower visitors were the hummingbirds Eupetomena macroura and Colibri serrirostris, which actively defended flowering mistletoes. The spatial separation between anthers, stigma and nectar chamber promotes pollen deposition on flapping wings of hovering hummingbirds that usually probe many flowers per visit. Seed set did not differ between hand-, self- and cross-pollinated flowers, but these treatments set significantly more seeds than flowers naturally exposed to flower visitors. We suggest that the limitation observed in the reproductive success of this plant is not related to pollinator scarcity, but probably to the extreme frequency of visitation by territorial hummingbirds. We conclude that the costs and benefits of plant reproduction depend on the interaction strength between flowers and pollinators, and the assessment of nectar secretion dynamics, pollinator behaviour and plant breeding system allows clarification of the complexity of such associations. PMID:24641568

  17. STRESS ETHYLENE EVOLUTION: A MEASURE OF OZONE AFFECTS ON PLANTS

    EPA Science Inventory

    To determine if ethylene evolution by plants is correlated with the ozone stress, a range of plants species and cultivars was exposed to varying ozone concentrations. Following exposure, the plants were encapsulated in plastic bags and incubated for up to 22h. The stress-induced ...

  18. The Arabidopsis DSO/ABCG11 transporter affects cutin metabolism in reproductive organs and suberin in roots.

    PubMed

    Panikashvili, David; Shi, Jian Xin; Bocobza, Samuel; Franke, Rochus Benni; Schreiber, Lukas; Aharoni, Asaph

    2010-05-01

    Apart from its significance in the protection against stress conditions, the cuticular cover is essential for proper development of the diverse surface structures formed on aerial plant organs. This layer mainly consists of a cutin matrix, embedded and overlaid with cuticular waxes. Following their biosynthesis in epidermal cells, cutin and waxes were suggested to be exported across the plasma membrane by ABCG-type transporters such as DSO/ABCG11 to the cell wall and further to extracellular matrix. Here, additional aspects of DSO/ABCG11 function were investigated, predominantly in reproductive organs, which were not revealed in the previous reports. This was facilitated by the generation of a transgenic DSO/ABCG11 silenced line (dso-4) that displayed relatively subtle morphological and chemical phenotypes. These included altered petal and silique morphology, fusion of seeds, and changes in levels of cutin monomers in flowers and siliques. The dso-4 phenotypes corresponded to the strong DSO/ABCG11 gene expression in the embryo epidermis as well as in the endosperm tissues of the developing seeds. Moreover, the DSO/ABCG11 protein displayed polar localization in the embryo protoderm. Transcriptome analysis of the dso-4 mutant leaves and stems showed that reduced DSO/ABCG11 activity suppressed the expression of a large number of cuticle-associated genes, implying that export of cuticular lipids from the plasma membrane is a rate-limiting step in cuticle metabolism. Surprisingly, root suberin composition of dso-4 was altered, as well as root expression of two suberin biosynthetic genes. Taken together, this study provides new insights into cutin and suberin metabolism and their role in reproductive organs and roots development. PMID:20035035

  19. Reproduction and distribution of fishes in a cooling lake: Wisconsin power plant impact study

    SciTech Connect

    Rondorf, D.W.; Kitchell, J.F.

    1985-06-01

    Spatial and temporal patterns during reproduction and early-life history of fishes were studied in a manmade cooling lake. Lake Columbia, impounded in 1974, near Portage, Wisconsin, has an area of 190 ha, a mean depth of 2.1 m, and a 15C temperature gradient derived from the thermal effluent of a 527-MW fossil-fueled generating station that began operating in 1975. The lake was initially colonized by fishes when filled with Wisconsin River water. Observations suggest a decline of species diversity of the fish community due to direct action of upper lethal temperatures, absence of colonization by warm-water, lake-dwelling species, and lack of recruitment for certain species. Spatial and temporal patterns of spawning of black crappie were altered by a rapid rise in water temperatures following plant startup after a three-week shutdown. Elevated temperatures subsequently shortened the spawning season, induced resorption of ova, and caused loss of secondary sexual characteristics. After initially drifting with water current, juvenile stages of sunfish and gizzard shad responded to changes in the thermal gradient by horizontal and vertical shifts in abundance.

  20. Geographic variation and the evolution of reproductive allocation in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Armbruster, P; Bradshaw, W E; Ruegg, K; Holzapfel, C M

    2001-02-01

    We measured the egg size of six geographic populations of the pitcher-plant mosquito, Wyeomyia smithii, from Florida (30 degrees N) to Ontario (49 degrees N). Populations from northern latitudes produced larger eggs than populations from southern latitudes. Egg size increased with increasing latitude more rapidly when larvae were reared under low rather than high density. One southern (30 degrees N) and one northern (49 degrees N) population of W. smithii that persisted through 10 generations of selection for increased persistence under conditions of chronic thermal- and nutrient-limiting stress (conditions similar to southern rather than northern habitats) produced smaller eggs more rapidly than unselected control lines. However, there were no differences in lifetime fecundity or fertility between control and selected lines. Thus, laboratory evolution in an environment representative of extreme southern latitudes caused evolutionary changes consistent with geographic patterns of egg size. These results implicate temperature as a selective factor influencing the geographic variation of egg size in W. smithii, and demonstrate a novel trade-off in reproductive allocation between egg size and egg maturation time. PMID:11308099

  1. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    PubMed

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. PMID:25666363

  2. Reproduction Does Not Adversely Affect Liver Mitochondrial Respiratory Function but Results in Lipid Peroxidation and Increased Antioxidants in House Mice

    PubMed Central

    Mowry, Annelise V.; Kavazis, Andreas N.; Sirman, Aubrey E.; Potts, Wayne K.; Hood, Wendy R.

    2016-01-01

    Reproduction is thought to come at a cost to longevity. Based on the assumption that increased energy expenditure during reproduction is associated with increased free-radical production by mitochondria, oxidative damage has been suggested to drive this trade-off. We examined the impact of reproduction on liver mitochondrial function by utilizing post-reproductive and non-reproductive house mice (Mus musculus) living under semi-natural conditions. The age-matched post-reproductive and non-reproductive groups were compared after the reproductive females returned to a non-reproductive state, so that both groups were in the same physiological state at the time the liver was collected. Despite increased oxidative damage (p = 0.05) and elevated CuZnSOD (p = 0.002) and catalase (p = 0.04) protein levels, reproduction had no negative impacts on the respiratory function of liver mitochondria. Specifically, in a post-reproductive, maintenance state the mitochondrial coupling (i.e., respiratory control ratio) of mouse livers show no negative impacts of reproduction. In fact, there was a trend (p = 0.059) to suggest increased maximal oxygen consumption by liver mitochondria during the ADP stimulated state (i.e., state 3) in post-reproduction. These findings suggest that oxidative damage may not impair mitochondrial respiratory function and question the role of mitochondria in the trade-off between reproduction and longevity. In addition, the findings highlight the importance of quantifying the respiratory function of mitochondria in addition to measuring oxidative damage. PMID:27537547

  3. Acetylesterase-Mediated Deacetylation of Pectin Impairs Cell Elongation, Pollen Germination, and Plant Reproduction

    SciTech Connect

    Gou J. Y.; Liu C.; Miller, L. M.; Hou, G.; Yu, X.-H.; Chen, X.-Y.

    2012-01-01

    Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility.

  4. Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish.

    PubMed

    Karjalainen, Juha; Urpanen, Olli; Keskinen, Tapio; Huuskonen, Hannu; Sarvala, Jouko; Valkeajärvi, Pentti; Marjomäki, Timo J

    2016-02-01

    Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populations with markedly different densities, and hence naturally induced differences in their growth and fecundity. The energy allocation to somatic tissues and eggs prior to spawning served as a proxy for total resource availability to individual females, and its effects on offspring survival and growth were analyzed. Vendace females allocated a rather constant proportion of available energy to eggs (per body mass) despite different growth patterns depending on the total resources in the different lakes; investment into eggs thus dictated the share remaining for growth. The energy allocation to eggs per mass was higher in young than in old spawners and the egg size and the relative fecundity differed between them: Young females produced more and smaller eggs and larvae than old spawners. In contrast to earlier observations of salmonids, a shortage of maternal food resources did not increase offspring size and survival. Vendace females in sparse populations with ample resources and high growth produced larger eggs and larvae. Vendace accommodate strong population fluctuations by their high plasticity in growth and fecundity, which affect their offspring size and consequently their recruitment and productivity, and account for their persistence and resilience in the face of high

  5. Pathway-based approaches for assessment of real-time exposure to an estrogenic wastewater treatment plant effluent on fathead minnow reproduction.

    PubMed

    Cavallin, Jenna E; Jensen, Kathleen M; Kahl, Michael D; Villeneuve, Daniel L; Lee, Kathy E; Schroeder, Anthony L; Mayasich, Joe; Eid, Evan P; Nelson, Krysta R; Milsk, Rebecca Y; Blackwell, Brett R; Berninger, Jason P; LaLone, Carlie A; Blanksma, Chad; Jicha, Terri; Elonen, Colleen; Johnson, Rodney; Ankley, Gerald T

    2016-03-01

    Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds, such as estrogens, which can affect the hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined reproductive effects in fathead minnows exposed for 21 d to a historically estrogenic WWTP effluent. Fathead minnow breeding pairs were held in control water or 1 of 3 effluent concentrations (5%, 20%, and 100%) in a novel onsite, flow-through system providing real-time exposure. The authors examined molecular and biochemical endpoints representing key events along adverse outcome pathways linking estrogen receptor activation and other molecular initiating events to reproductive impairment. In addition, the authors used chemical analysis of the effluent to construct a chemical-gene interaction network to aid in targeted gene expression analyses and identifying potentially impacted biological pathways. Cumulative fecundity was significantly reduced in fish exposed to 100% effluent but increased in those exposed to 20% effluent, the approximate dilution factor in the receiving waters. Plasma vitellogenin concentrations in males increased in a dose-dependent manner with effluent concentration; however, male fertility was not impacted. Although in vitro analyses, analytical chemistry, and biomarker responses confirmed the effluent was estrogenic, estrogen receptor agonists were unlikely the primary driver of impaired reproduction. The results provide insights into the significance of pathway-based effects with regard to predicting adverse reproductive outcomes. Environ Toxicol Chem 2016;35:702-716. Published 2015 by Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work, and as such, is in the public domain in the United States of America. PMID:26332155

  6. Affective imagery and acceptance of replacing nuclear power plants.

    PubMed

    Keller, Carmen; Visschers, Vivianne; Siegrist, Michael

    2012-03-01

    This study examined the relationship between the content of spontaneous associations with nuclear power plants and the acceptance of using new-generation nuclear power plants to replace old ones. The study also considered gender as a variable. A representative sample of the German- and French-speaking population of Switzerland (N= 1,221) was used. Log-linear models revealed significant two-way interactions between the association content and acceptance, association content and gender, and gender and acceptance. Correspondence analysis revealed that participants who were opposed to nuclear power plants mainly associated nuclear power plants with risk, negative feelings, accidents, radioactivity, waste disposal, military use, and negative consequences for health and environment; whereas participants favoring nuclear power plants mainly associated them with energy, appearance descriptions of nuclear power plants, and necessity. Thus, individuals opposing nuclear power plants had both more concrete and more diverse associations with them than people who were in favor of nuclear power plants. In addition, participants who were undecided often mentioned similar associations to those participants who were in favor. Males more often expressed associations with energy, waste disposal, and negative health effects. Females more often made associations with appearance descriptions, negative feelings, and negative environmental effects. The results further suggest that acceptance of replacing nuclear power plants was higher in the German-speaking part of the country, where all of the Swiss nuclear power plants are physically located. Practical implications for risk communication are discussed. PMID:21977961

  7. Mutations of the Drosophila Myosin Regulatory Light Chain Affect Courtship Song and Reduce Reproductive Success

    PubMed Central

    Chakravorty, Samya; Vu, Hien; Foelber, Veronica; Vigoreaux, Jim O.

    2014-01-01

    The Drosophila indirect flight muscles (IFM) rely on an enhanced stretch-activation response to generate high power output for flight. The IFM is neurally activated during the male courtship song, but its role, if any, in generating the small amplitude wing vibrations that produce the song is not known. Here, we examined the courtship song properties and mating behavior of three mutant strains of the myosin regulatory light chain (DMLC2) that are known to affect IFM contractile properties and impair flight: (i) Dmlc2Δ2–46 (Ext), an N-terminal extension truncation; (ii) Dmlc2S66A,S67A (Phos), a disruption of two MLC kinase phosphorylation sites; and (iii) Dmlc2Δ2–46;S66A,S67A (Dual), expressing both mutations. Our results show that the Dmlc2 gene is pleiotropic and that mutations that have a profound effect on flight mechanics (Phos and Dual) have minimal effects on courtship song. None of the mutations affect interpulse interval (IPI), a determinant of species-specific song, and intrapulse frequency (IPF) compared to Control (Dmlc2+ rescued null strain). However, abnormalities in the sine song (increased frequency) and the pulse song (increased cycles per pulse and pulse length) evident in Ext males are not apparent in Dual males suggesting that Ext and Phos interact differently in song and flight mechanics, given their known additive effect on the latter. All three mutant males produce a less vigorous pulse song and exhibit impaired mating behavior compared to Control males. As a result, females are less receptive to Ext, Phos, and Dual males when a Control male is present. These results open the possibility that DMLC2, and perhaps contractile protein genes in general, are partly under sexual selection. That mutations in DMLC2 manifest differently in song and flight suggest that this protein fulfills different roles in song and flight and that stretch activation plays a smaller role in song production than in flight. PMID:24587213

  8. Nutrient enrichment affects the mechanical resistance of aquatic plants.

    PubMed

    Lamberti-Raverot, Barbara; Puijalon, Sara

    2012-10-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

  9. The unmanaged reproductive ecology of domesticated plants in traditional agroecosystems: An example involving cassavaand a call for data

    NASA Astrophysics Data System (ADS)

    Elias, Marianne; McKey, Doyle

    2000-05-01

    Although cassava is a strictly vegetatively propagated crop, in many traditional Amazonian agroecosystems, Amerindian farmers recognise volunteer seedlings of cassava and allow them to grow. If their properties are deemed desirable, plants originating from seedlings are included in the harvest of tuberous roots, and their stems are used to prepare cuttings for propagation. Incorporation of these products of spontaneous sexual reproduction appears to be important in origin and maintenance of genetic diversity in this clonally propagated plant. Our observations conducted in an Amerindian village in Guyana suggest that volunteer seedlings arise from a bank of viable seeds stored in soil, and that dispersal and burial of seeds by ants may be important in its constitution. Future investigations of the dynamics of genetic diversity in this crop in traditional agroecosystems must consider the role of the 'wild' sexual reproduction that occurs in parallel with vegetative propagation. We suggest that unmanaged processes of sexual reproduction play important but neglected roles in the evolutionary ecology of many domesticated plants in traditional agroecosystems.

  10. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field.

    PubMed

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-03-29

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits inArabidopsis thaliana To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics ofA. thaliana. PMID:26979961

  11. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field

    PubMed Central

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-01-01

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana. To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics of A. thaliana. PMID:26979961

  12. THE ESTROGENIC AND ANTIANDROGENIC PESTICIDE METHOXYCHLOR ALTERS THE REPRODUCTIVE TRACT AND BEHAVIOR WITHOUT AFFECTING PITUITARY SIZE OR LH AND PROLACTIN SECRETION IN MALE RATS

    EPA Science Inventory

    The estrogenic and antiandrogenic pesticide methoxychlor alters the reproductive tract and behavior without affecting pituitary size or LH and prolactin secretion in male rats.

    Gray LE Jr, Ostby J, Cooper RL, Kelce WR.

    Endocrinology Branch, United States Environment...

  13. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens

    PubMed Central

    HARWOOD, JAMES F.; CHEN, KEHUI; LIEDO, PABLO; MÜLLER, HANS-GEORG; WANG, JANE-LING; MORICE, AMY E.; CAREY, JAMES R.

    2014-01-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males’ access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability. PMID:25709143

  14. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

    PubMed

    Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

    2016-01-01

    Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture. PMID:27213896

  15. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster

    PubMed Central

    Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

    2016-01-01

    Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture. PMID:27213896

  16. Factors Affecting Location Decisions of Food Processing Plants

    NASA Astrophysics Data System (ADS)

    Turhan, Sule; Canan Ozbag, Basak; Cetin, Bahattin

    The main aim of this study is to examine the determinants of location choices for food processing plants using the results of 59 personal surveys. The 61.3% of the food processing plants that were interviewed are small scale plants, 9.1% are large scale plants and 29.6% are medium scale plants. Sixteen of the firms process vegetables, 12 process poultry, 12 process dairy and 9 process seafood products. Business climate factors are divided into six categories (market, infrastructure, raw material, labor, personal and environmental) and 17 specific location factors are considered. The survey responses are analyzed by types of raw materials processed and by plant size. 43.7, 55.3 and 42.2% of the respondents cited categories of Market, Raw Material and Infrastructure respectively as important, while 44.3, 50.7 and 74.4% of the respondents cited, labor, personal and environmental regulation categories of as not important. Thus survey findings indicate that plant location choices are mainly driven by market, raw material and infra structural factors. Environmental factors such as environmental regulations and permissions are relatively insignificant.

  17. Living in isolation – population structure, reproduction, and genetic variation of the endangered plant species Dianthus gratianopolitanus (Cheddar pink)

    PubMed Central

    Putz, Christina M; Schmid, Christoph; Reisch, Christoph

    2015-01-01

    The endangered plant species Dianthus gratianopolitanus exhibits a highly fragmented distribution range comprising many isolated populations. Based upon this pattern of distribution, we selected a study region in Switzerland with a lower magnitude of isolation (Swiss Jura) and another study region in Germany with a higher degree of isolation (Franconian Jura). In each region, we chose ten populations to analyze population structure, reproduction, and genetic variation in a comparative approach. Therefore, we determined population density, cushion size, and cushion density to analyze population structure, investigated reproductive traits, including number of flowers, capsules, and germination rate, and analyzed amplified fragment length polymorphisms to study genetic variation. Population and cushion density were credibly higher in German than in Swiss populations, whereas reproductive traits and genetic variation within populations were similar in both study regions. However, genetic variation among populations and isolation by distance were stronger in Germany than in Switzerland. Generally, cushion size and density as well as flower and capsule production increased with population size and density, whereas genetic variation decreased with population density. In contrast to our assumptions, we observed denser populations and cushions in the region with the higher magnitude of isolation, whereas reproductive traits and genetic variation within populations were comparable in both regions. This corroborates the assumption that stronger isolation must not necessarily result in the loss of fitness and genetic variation. Furthermore, it supports our conclusion that the protection of strongly isolated populations contributes essentially to the conservation of a species' full evolutionary potential. PMID:26380690

  18. Factors affecting plant growth in membrane nutrient delivery

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Wheeler, R. M.; Sager, J. C.; Knott, W. M.

    1990-01-01

    The development of the tubular membrane plant growth unit for the delivery of water and nutrients to roots in microgravity has recently focused on measuring the effects of changes in physical variables controlling solution availability to the plants. Significant effects of membrane pore size and the negative pressure used to contain the solution were demonstrated. Generally, wheat grew better in units with a larger pore size but equal negative pressure and in units with the same pore size but less negative pressure. Lettuce also exhibited better plant growth at less negative pressure.

  19. Population rules can apply to individual plants and affect their architecture: an evaluation on the cushion plant Mulinum spinosum (Apiaceae)

    PubMed Central

    Puntieri, Javier G.; Damascos, María A.; Llancaqueo, Yanina; Svriz, Maya

    2010-01-01

    Background and aims Plants are regarded as populations of modules such as axes and growth units (GUs, i.e. seasonally produced axis segments). Due to their dense arrays of GUs, cushion plants may resemble crowded plant populations in the way the number of components (GUs in plants, individuals in populations) relates to their individual sizes. Methodology The morphological differentiation of GUs and its relationship with biomass accumulation and plant size were studied for the cushion subshrub Mulinum spinosum (Apiaceae), a widespread species in dry areas of Patagonia. In 2009, GUs were sampled from one-quarter of each of 24 adult plants. Within- and between-plant variations in GU length, diameter, number of nodes and biomass were analysed and related to whole-plant size. Principal results Each year, an M. spinosum cushion develops flowering GUs and vegetative GUs. Flowering GUs are larger, twice as numerous and contain two to four times more dry mass (excluding reproductive structures) than vegetative GUs. The hemispherical area of the cushions was positively correlated with the biomass of last-year GUs. The biomass of flowering GUs was negatively correlated with the density of GUs. Mulinum spinosum plants exhibited a notable differentiation between flowering and vegetative GUs, but their axes, i.e. the sequences of GUs, were not differentiated throughout the plants. Flowering GUs comprised a major proportion of each plant's photosynthetic tissues. Conclusions A decrease in the size of flowering GUs and in their number relative to the total number of GUs per plant, parallel to an increase in GU density, is predicted as M. spinosum plants age over years. The assimilative role of vegetative GUs is expected to increase in summer because of their less exposed position in the cushion. These GUs would therefore gain more from warm and dry conditions than flowering GUs. PMID:22476077

  20. Southern rice black-streaked dwarf virus (SRBSDV) directly affects the feeding and reproduction behavior of its vector, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

    PubMed Central

    2014-01-01

    Background Southern rice black-streaked dwarf virus (SRBSDV) is a recently discovered member of the genus Fijivirus and it is transmitted by the rice whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). It was found that SRBSDV infected vectors might contribute negatively to the WBPH population, although the longer nymphal period might benefit viral acquisition, transmission and increase infection rate. The interaction between SRBSDV and its vector need to be further explored to gain better understanding of the dispersal of WBPH and the spread of virus disease, in particular the feeding and reproduction behavior of viruliferous WBPH. Methods Newly hatched nymphs of WBPH were fed on healthy rice plant after feeding on SRBSDV-infected rice plants for 2 h, and newly emerged adults were numbered and tested. Feeding behaviors of WBPH adults were monitored electronically within a Faraday cage using a Giga-4 DC EPG amplifier. The newly emerged adults were paired, and the fecundity and egg hatchability were investigated. WBPH was molecularly identified for SRBSDV when they dead. According to the identification results, data on viruliferous and non-viruliferous WBPH were collected and analyzed. Results Feeding behavior of viruliferous WBPH was different from those of non-viruliferous WBPH. Frequency of phloem sap ingestion of viruliferous WBPH increased significantly, however the total feeding duration did not increase markedly. When both WBPH parents were infected with SRBSDV, their fecundity and hatchability of the eggs produced were significant lower than those of normal WBPH parents. However, if only one of the parents was viruliferous, fecundity and egg hatchability were only slightly affected. Conclusions Viruliferous WBPH fed on the phloem more frequently than non-viruliferous WBPH and can thus contribute to virus transmission. When both vector parents are viruliferous fecundity and hatchability of the eggs were significantly reduced. However when only

  1. A novel family of small proteins that affect plant development

    SciTech Connect

    John Charles Walker

    2011-04-29

    The DVL genes represent a new group of plant proteins that influence plant growth and development. Overexpression of DVL1, and other members of the DVL family, causes striking phenotypic changes. The DVL proteins share sequence homology in their C-terminal half. Point mutations in the C-terminal domain show it is necessary and deletion studies demonstrate the C-terminal domain is sufficient to confer the overexpression phenotypes. The phenotypes observed, and the conservation of the protein sequence in the plant kingdom, does suggest the DVL proteins have a role in modulating plant growth and development. Our working hypothesis is the DVL proteins function as regulators of cellular signaling pathways that control growth and development.

  2. Factors affecting reproductive performance of white-tailed deer subjected to fixed-time artificial insemination or natural mating.

    PubMed

    Mellado, Miguel; Orta, Claudia G; Lozano, Eloy A; García, Jose E; Veliz, Francisco G; de Santiago, Angeles

    2013-01-01

    The objectives of this study were to examine the effects of several factors affecting fawning rate, litter size, litter weight and neonatal fawn mortality in white-tailed deer inseminated either transcervically or by means of laparoscopy. Oestrus synchronisation with a controlled internal drug release (CIDR)-based protocol and fixed-time artificial insemination (FTAI) was conducted in 130 white-tailed deer (Odocoileus virginianus texanus) during three reproductive seasons (2007-2009; 271 services) in a game-hunting ranch in a hot-arid environment (26°4' N, 101°25' W). Ninety additional non-treated does were exposed to bucks for natural mating. Fawning rate did not differ between AI methods (40.0 vs 45.0% for transcervical and laparoscopic AI, respectively). Overall fawning rate (proportion of all does fawning after FTAI and a subsequent period of buck exposure) did not differ between transcervical (89.5%), laparoscopic (80.3%) or natural (88.9%) insemination. Litter size per fawning doe was higher (P<0.05) in naturally-served does (1.65±0.48) than in transcervically-inseminated does (1.40±0.51) or in laparoscopically-inseminated does (1.48±0.50). The main conclusion was that no enhancement of fawning rate or litter size occurred as a result of intrauterine deposition of semen by laparoscopy compared with the transcervical insemination technique. PMID:23464502

  3. Developmental Exposure to Ethinylestradiol Affects Reproductive Physiology, the GnRH Neuroendocrine Network and Behaviors in Female Mouse

    PubMed Central

    Derouiche, Lyes; Keller, Matthieu; Martini, Mariangela; Duittoz, Anne H.; Pillon, Delphine

    2015-01-01

    During development, environmental estrogens are able to induce an estrogen mimetic action that may interfere with endocrine and neuroendocrine systems. The present study investigated the effects on the reproductive function in female mice following developmental exposure to pharmaceutical ethinylestradiol (EE2), the most widespread and potent synthetic steroid present in aquatic environments. EE2 was administrated in drinking water at environmentally relevant (ENVIR) or pharmacological (PHARMACO) doses [0.1 and 1 μg/kg (body weight)/day respectively], from embryonic day 10 until postnatal day 40. Our results show that both groups of EE2-exposed females had advanced vaginal opening and shorter estrus cycles, but a normal fertility rate compared to CONTROL females. The hypothalamic population of GnRH neurons was affected by EE2 exposure with a significant increase in the number of perikarya in the preoptic area of the PHARMACO group and a modification in their distribution in the ENVIR group, both associated with a marked decrease in GnRH fibers immunoreactivity in the median eminence. In EE2-exposed females, behavioral tests highlighted a disturbed maternal behavior, a higher lordosis response, a lack of discrimination between gonad-intact and castrated males in sexually experienced females, and an increased anxiety-related behavior. Altogether, these results put emphasis on the high sensitivity of sexually dimorphic behaviors and neuroendocrine circuits to disruptive effects of EDCs. PMID:26696819

  4. Fuel breaks affect nonnative species abundance in Californian plant communities

    USGS Publications Warehouse

    Merriam, K.E.; Keeley, J.E.; Beyers, J.L.

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.

  5. Rhizosphere microbiome assemblage is affected by plant development

    PubMed Central

    Chaparro, Jacqueline M; Badri, Dayakar V; Vivanco, Jorge M

    2014-01-01

    There is a concerted understanding of the ability of root exudates to influence the structure of rhizosphere microbial communities. However, our knowledge of the connection between plant development, root exudation and microbiome assemblage is limited. Here, we analyzed the structure of the rhizospheric bacterial community associated with Arabidopsis at four time points corresponding to distinct stages of plant development: seedling, vegetative, bolting and flowering. Overall, there were no significant differences in bacterial community structure, but we observed that the microbial community at the seedling stage was distinct from the other developmental time points. At a closer level, phylum such as Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and specific genera within those phyla followed distinct patterns associated with plant development and root exudation. These results suggested that the plant can select a subset of microbes at different stages of development, presumably for specific functions. Accordingly, metatranscriptomics analysis of the rhizosphere microbiome revealed that 81 unique transcripts were significantly (P<0.05) expressed at different stages of plant development. For instance, genes involved in streptomycin synthesis were significantly induced at bolting and flowering stages, presumably for disease suppression. We surmise that plants secrete blends of compounds and specific phytochemicals in the root exudates that are differentially produced at distinct stages of development to help orchestrate rhizosphere microbiome assemblage. PMID:24196324

  6. Plant surface wax affects parasitoid's response to host footprints

    NASA Astrophysics Data System (ADS)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  7. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    ERIC Educational Resources Information Center

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  8. Regression analysis of technical parameters affecting nuclear power plant performances

    SciTech Connect

    Ghazy, R.; Ricotti, M. E.; Trueco, P.

    2012-07-01

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  9. Disentangling Facilitation Along the Life Cycle: Impacts of Plant-Plant Interactions at Vegetative and Reproductive Stages in a Mediterranean Forb.

    PubMed

    García-Cervigón, Ana I; Iriondo, José M; Linares, Juan C; Olano, José M

    2016-01-01

    Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant-plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels, and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant-plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower, and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant-plant interactions. PMID:26904086

  10. Cadmium content of plants as affected by soil cadmium concentration

    SciTech Connect

    Lehoczky, E.; Szabados, I.; Marth, P.

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  11. How neighbor canopy architecture affects target plant performance

    SciTech Connect

    Tremmel, D.C.; Bazzaz, F.A. )

    1993-10-01

    Plant competition occurs through the negative effects that individual plants have on resource availability to neighboring individuals. Therefore competition experiments need to examine how different species change resource availability to their neighbors, and how different species respond to these changes-allocationally, architecturally, and physiologically-through time. In a greenhouse study we used a model system of annuals to examine how canopies of species having differing morphologies differed in their architectures and light-interception abilities, and how different species performed when grown in these canopies. Abutilon theophrasti, Datura stramonium, and Polygonum pensylvanicum were grown as [open quotes]targets[close quotes]. Plants were grown in pots, with one target plant and four neighbor plants. Detailed measurements of neighbor canopy structure and target plant canopy architecture were made at five harvests. Species with different morphologies showed large differences in canopy structure, particularly when grass and forb species were compared. Setaria, a grass, had a more open canopy than the other species (all forbs), and was a consistently weak competitor. Overall, however, the relative effects of different neighbors on target biomass varied with target species. Target biomass was poorly correlated with neighbor biomass and leaf area, but was highly correlated with a measure of target light-interception ability that took into account both target leaf deployment and neighbor light interception. Despite clear differences among neighbor species in canopy structure and effect on light penetration, the results suggest no broad generalizations about the effects of different species as neighbors. Knowledge of morphological, physiological, and life history characteristics of both the target and neighbor species may be necessary to explain the results of their competition. 53 refs., 4 figs., 4 tabs.

  12. Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

    PubMed

    Richard, Antoine; Dionne, Mélanie; Wang, Jinliang; Bernatchez, Louis

    2013-01-01

    In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success. PMID:23163395

  13. Using Genetic Markers to Directly Estimate Gene Flow and Reproductive Success Parameters in Plants on the Basis of Naturally Regenerated Seedlings

    PubMed Central

    Burczyk, J.; Adams, W. T.; Birkes, D. S.; Chybicki, I. J.

    2006-01-01

    Estimating seed and pollen gene flow in plants on the basis of samples of naturally regenerated seedlings can provide much needed information about “realized gene flow,” but seems to be one of the greatest challenges in plant population biology. Traditional parentage methods, because of their inability to discriminate between male and female parentage of seedlings, unless supported by uniparentally inherited markers, are not capable of precisely describing seed and pollen aspects of gene flow realized in seedlings. Here, we describe a maximum-likelihood method for modeling female and male parentage in a local plant population on the basis of genotypic data from naturally established seedlings and when the location and genotypes of all potential parents within the population are known. The method models female and male reproductive success of individuals as a function of factors likely to influence reproductive success (e.g., distance of seed dispersal, distance between mates, and relative fecundity–i.e., female and male selection gradients). The method is designed to account for levels of seed and pollen gene flow into the local population from unsampled adults; therefore, it is well suited to isolated, but also wide-spread natural populations, where extensive seed and pollen dispersal complicates traditional parentage analyses. Computer simulations were performed to evaluate the utility and robustness of the model and estimation procedure and to assess how the exclusion power of genetic markers (isozymes or microsatellites) affects the accuracy of the parameter estimation. In addition, the method was applied to genotypic data collected in Scots pine (isozymes) and oak (microsatellites) populations to obtain preliminary estimates of long-distance seed and pollen gene flow and the patterns of local seed and pollen dispersal in these species. PMID:16489237

  14. Plant extracts affect in vitro rumen microbial fermentation.

    PubMed

    Busquet, M; Calsamiglia, S; Ferret, A; Kamel, C

    2006-02-01

    Different doses of 12 plant extracts and 6 secondary plant metabolites were incubated for 24 h in diluted ruminal fluid with a 50:50 forage:concentrate diet. Treatments were: control (no additive), plant extracts (anise oil, cade oil, capsicum oil, cinnamon oil, clove bud oil, dill oil, fenugreek, garlic oil, ginger oil, oregano oil, tea tree oil, and yucca), and secondary plant metabolites (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol). Each treatment was supplied at 3, 30, 300, and 3,000 mg/L of culture fluid. At 3,000 mg/L, most treatments decreased total volatile fatty acid concentration, but cade oil, capsicum oil, dill oil, fenugreek, ginger oil, and yucca had no effect. Different doses of anethol, anise oil, carvone, and tea tree oil decreased the proportion of acetate and propionate, which suggests that these compounds may not be nutritionally beneficial to dairy cattle. Garlic oil (300 and 3,000 mg/L) and benzyl salicylate (300 and 3,000 mg/L) reduced acetate and increased propionate and butyrate proportions, suggesting that methane production was inhibited. At 3,000 mg/L, capsicum oil, carvacrol, carvone, cinnamaldehyde, cinnamon oil, clove bud oil, eugenol, fenugreek, and oregano oil resulted in a 30 to 50% reduction in ammonia N concentration. Careful selection and combination of these extracts may allow the manipulation of rumen microbial fermentation. PMID:16428643

  15. Maximizing plant density affects broccoli yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased demand for fresh market bunch broccoli (Brassica oleracea L. var. italica) has led to increased production along the United States east coast. Maximizing broccoli yields is a primary concern for quickly expanding southeastern commercial markets. This broccoli plant density study was carr...

  16. Factors Affecting Distribution of Estrogenicity in the Influents, Effluents, and Biosolids of Canadian Wastewater Treatment Plants.

    PubMed

    Shieh, Ben H H; Louie, Alvin; Law, Francis C P

    2016-05-01

    Canadian wastewater treatment plants (WWTPs) release significant amounts of estrogenic chemicals to nearby surface waters. Environmental estrogens have been implicated as the causative agents of many developmental and reproductive problems in animals, including fish. The goals of this study were to assess the estrogenic activity in the influents, effluents, and biosolids of thirteen Canadian WWTPs using the yeast estrogen screen (YES) bioassay and to investigate whether factors, such as wastewater treatment method, sample storage, extraction efficiency, population, and summer/winter temperature had any effects on the distribution of estrogenicity in the WWTPs. Results of the study showed that estrogenicity from the influent to the effluent decreased in seven WWTPs, increased in two WWTPs, and did not change in four WWTPs during the winter. Estrogenic concentrations generally decreased in the order of biosolids > influents > effluents and ranged from 1.57 to 24.6, 1.25E-02 to 3.84E-01, and 9.46E-03 to 3.90E-01 ng estradiol equivalents/g or ml, respectively. The estrogenicity in the final effluents, but not those in the influents and biosolids, was significantly higher in the summer than the winter. Among the WWTP treatment methods, advanced, biological nutrient removal appeared to be the most effective method to remove estrogenic chemicals from wastewaters in Canada. Our studies help to identify factors or mechanisms that affect the distribution of estrogenicity in WWTPs, providing a better understanding on the discharges of estrogenic chemicals from WWTPs. PMID:26433808

  17. Herbivory of an invasive slug is affected by earthworms and the composition of plant communities

    PubMed Central

    2013-01-01

    Background Biodiversity loss and species invasions are among the most important human-induced global changes. Moreover, these two processes are interlinked as ecosystem invasibility is considered to increase with decreasing biodiversity. In temperate grasslands, earthworms serve as important ecosystem engineers making up the majority of soil faunal biomass. Herbivore behaviour has been shown to be affected by earthworms, however it is unclear whether these effects differ with the composition of plant communities. To test this we conducted a mesocosm experiment where we added earthworms (Annelida: Lumbricidae) to planted grassland communities with different plant species composition (3 vs. 12 plant spp.). Plant communities had equal plant densities and ratios of the functional groups grasses, non-leguminous forbs and legumes. Later, Arion vulgaris slugs (formerly known as A. lusitanicus; Gastropoda: Arionidae) were added and allowed to freely choose among the available plant species. This slug species is listed among the 100 worst alien species in Europe. We hypothesized that (i) the food choice of slugs would be altered by earthworms’ specific effects on the growth and nutrient content of plant species, (ii) slug herbivory will be less affected by earthworms in plant communities containing more plant species than in those with fewer plant species because of a more readily utilization of plant resources making the impacts of earthworms less pronounced. Results Slug herbivory was significantly affected by both earthworms and plant species composition. Slugs damaged 60% less leaves when earthworms were present, regardless of the species composition of the plant communities. Percent leaf area consumed by slugs was 40% lower in communities containing 12 plant species; in communities containing only three species earthworms increased slug leaf area consumption. Grasses were generally avoided by slugs. Leaf length and number of tillers was increased in mesocosms

  18. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes.

    PubMed

    Clifton, Mark E; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G

    2014-05-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as "activating" egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: (1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? (2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? (3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female's resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle's likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the "activating" effect of mating described as well as the role sugar feeding plays in male mosquitoes. PMID:24657670

  19. Reproductive responses of male fathead minnows exposed to wastewater treatment plant effluent, effluent treated with XAD8 resin, and an environmentally relevant mixture of alkylphenol compounds

    USGS Publications Warehouse

    Barber, L.B.; Lee, K.E.; Swackhamer, D.L.; Schoenfuss, H.L.

    2007-01-01

    On-site, continuous-flow experiments were conducted during August and October 2002 at a major metropolitan wastewater treatment plant (WWTP) to determine if effluent exposure induced endocrine disruption as manifested in the reproductive competence of sexually mature male fathead minnows (Pimephales promelas). The fathead minnows were exposed in parallel experiments to WWTP effluent and WWTP effluent treated with XAD8 macroreticular resin to remove the hydrophobic-neutral fraction which contained steroidal hormones, alkylphenolethoxylates (APEs), and other potential endocrine disrupting compounds (EDCs). The effluent composition varied on a temporal scale and the continuous-flow experiments captured the range of chemical variability that occurred during normal WWTP operations. Exposure to WWTP effluent resulted in vitellogenin induction in male fathead minnows, with greater response in October than in August. Concentrations of ammonia, APEs, 17??-estradiol, and other EDCs also were greater in October than in August, reflecting a change in effluent composition. In the October experiment, XAD8 treatment significantly reduced vitellogenin induction in the male fathead minnows relative to the untreated effluent, whereas in August, XAD8 treatment had little effect. During both experiments, XAD8 treatment removed greater than 90% of the APEs. Exposure of fish to a mixture of APEs similar in composition and concentration to the WWTP effluent, but prepared in groundwater and conducted at a separate facility, elicited vitellogenin induction during both experiments. There was a positive relation between vitellogenin induction and hepatosomatic index (HSI), but not gonadosomatic index (GSI), secondary sexual characteristics index (SSCI), or reproductive competency. In contrast to expectations, the GSI and SSCI increased in males exposed to WWTP effluent compared to groundwater controls. The GSI, SSCI, and reproductive competency were positively affected by XAD8 treatment of

  20. Reproductive responses of male fathead minnows exposed to wastewater treatment plant effluent, effluent treated with XAD8 resin, and an environmentally relevant mixture of alkylphenol compounds.

    PubMed

    Barber, Larry B; Lee, Kathy E; Swackhamer, Deborah L; Schoenfuss, Heiko L

    2007-04-20

    On-site, continuous-flow experiments were conducted during August and October 2002 at a major metropolitan wastewater treatment plant (WWTP) to determine if effluent exposure induced endocrine disruption as manifested in the reproductive competence of sexually mature male fathead minnows (Pimephales promelas). The fathead minnows were exposed in parallel experiments to WWTP effluent and WWTP effluent treated with XAD8 macroreticular resin to remove the hydrophobic-neutral fraction which contained steroidal hormones, alkylphenolethoxylates (APEs), and other potential endocrine disrupting compounds (EDCs). The effluent composition varied on a temporal scale and the continuous-flow experiments captured the range of chemical variability that occurred during normal WWTP operations. Exposure to WWTP effluent resulted in vitellogenin induction in male fathead minnows, with greater response in October than in August. Concentrations of ammonia, APEs, 17beta-estradiol, and other EDCs also were greater in October than in August, reflecting a change in effluent composition. In the October experiment, XAD8 treatment significantly reduced vitellogenin induction in the male fathead minnows relative to the untreated effluent, whereas in August, XAD8 treatment had little effect. During both experiments, XAD8 treatment removed greater than 90% of the APEs. Exposure of fish to a mixture of APEs similar in composition and concentration to the WWTP effluent, but prepared in groundwater and conducted at a separate facility, elicited vitellogenin induction during both experiments. There was a positive relation between vitellogenin induction and hepatosomatic index (HSI), but not gonadosomatic index (GSI), secondary sexual characteristics index (SSCI), or reproductive competency. In contrast to expectations, the GSI and SSCI increased in males exposed to WWTP effluent compared to groundwater controls. The GSI, SSCI, and reproductive competency were positively affected by XAD8 treatment of

  1. CRF-Like Diuretic Hormone Negatively Affects Both Feeding and Reproduction in the Desert Locust, Schistocerca gregaria

    PubMed Central

    Van Wielendaele, Pieter; Dillen, Senne; Marchal, Elisabeth; Badisco, Liesbeth; Vanden Broeck, Jozef

    2012-01-01

    Diuretic hormones (DH) related to the vertebrate Corticotropin Releasing Factor (CRF) have been identified in diverse insect species. In the migratory locust, Locusta migratoria, the CRF-like DH (CRF/DH) is localized in the same neurosecretory cells as the Ovary Maturating Parsin (OMP), a neurohormone that stimulates oocyte growth, vitellogenesis and hemolymph ecdysteroid levels in adult female locusts. In this study, we investigated whether CRF-like DH can influence feeding and reproduction in the desert locust, Schistocerca gregaria. We identified two highly similar S. gregaria CRF-like DH precursor cDNAs, each of which also encodes an OMP isoform. Alignment with other insect CRF-like DH precursors shows relatively high conservation of the CRF/DH sequence while the precursor region corresponding to OMP is not well conserved. Quantitative real-time RT-PCR revealed that the precursor transcripts mainly occur in the central nervous system and their highest expression level was observed in the brain. Injection of locust CRF/DH caused a significantly reduced food intake, while RNAi knockdown stimulated food intake. Therefore, our data indicate that CRF-like DH induces satiety. Furthermore, injection of CRF/DH in adult females retarded oocyte growth and caused lower ecdysteroid titers in hemolymph and ovaries, while RNAi knockdown resulted in opposite effects. The observed effects of CRF/DH may be part of a wider repertoire of neurohormonal activities, constituting an integrating control system that affects food intake and excretion, as well as anabolic processes like oocyte growth and ecdysteroidogenesis, following a meal. Our discussion about the functional relationship between CRF/DH and OMP led to the hypothesis that OMP may possibly act as a monitoring peptide that can elicit negative feedback effects. PMID:22363645

  2. Volatile Exchange between Undamaged Plants - a New Mechanism Affecting Insect Orientation in Intercropping

    PubMed Central

    Ninkovic, Velemir; Dahlin, Iris; Vucetic, Andja; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben

    2013-01-01

    Changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. However, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. We investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. Consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamaged onion plants identified by mass spectrometry. Using live plants and synthetic blends mimicking exposed and unexposed potato, we tested the olfactory response of winged aphids, Myzus persicae. The altered potato volatile profile deterred aphids in laboratory experiments. Further, we show that growing potato together with onion in the field reduces the abundance of winged, host-seeking aphids. Our study broadens the ecological significance of the phenomenon; volatiles carry not only information on whether or not neighbouring plants are under attack, but also information on the emitter plants themselves. In this way responding plants could obtain information on whether the neighbouring plant is a competitive threat and can accordingly adjust their growth towards it. We interpret this as a response in the process of adaptation towards neighbouring plants. Furthermore, these physiological changes in the responding plants have significant ecological impact, as behaviour of aphids was affected. Since herbivore host plants are potentially under constant exposure to these volatiles, our study has major implications for the understanding of how mechanisms within plant communities affect insects. This knowledge could be used to improve plant protection and increase scientific understanding of communication between plants and its impact on other organisms. PMID:23922710

  3. Long-term reproductive behaviour of woody plants across seven Bornean forest types in the Gunung Palung National Park (Indonesia): suprannual synchrony, temporal productivity and fruiting diversity.

    PubMed

    Cannon, Charles H; Curran, Lisa M; Marshall, Andrew J; Leighton, Mark

    2007-10-01

    For 68 months, we observed the reproductive behaviour of 7288 woody plants (172 figs, 1457 climbers and 5659 trees) spanning major soil and elevational gradients. Two 2-3 month community-wide supra-annual fruiting events were synchronized across five forest types, coinciding with ENSO events. At least 27 genera in 24 families restricted their reproduction to these events, which involved a substantial proportion of tree diversity (> 80% of phylogenetic diversity). During these events, mean reproductive levels (8.5%) represented an almost four-fold increase compared with other months. These patterns indicate a strong behavioural advantage to this unusual reproductive behaviour. Montane forest experienced a single, separate fruiting peak while the peat swamp forest did not participate. Excluding these events, no temporal reproductive pattern was detectable, at either the landscape or forest type. These phenological patterns have major implications for the conservation of frugivore communities, with montane and swamp forests acting as 'keystone' forests. PMID:17845296

  4. Plants and Photosynthesis: Level III, Unit 3, Lesson 1; The Human Digestive System: Lesson 2; Functions of the Blood: Lesson 3; Human Circulation and Respiration: Lesson 4; Reproduction of a Single Cell: Lesson 5; Reproduction by Male and Female Cells: Lesson 6; The Human Reproductive System: Lesson 7; Genetics and Heredity: Lesson 8; The Nervous System: Lesson 9; The Glandular System: Lesson 10. Advanced General Education Program. A High School Self-Study Program.

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. Job Corps.

    This self-study program for the high-school level contains lessons in the following subjects: Plants and Photosynthesis; The Human Digestive System; Functions of the Blood; Human Circulation and Respiration; Reproduction of a Single Cell; Reproduction by Male and Female Cells; The Human Reproductive System; Genetics and Heredity; The Nervous…

  5. Solanum malacoxylon: a toxic plant which affects animal calcium metabolism.

    PubMed

    Boland, R L

    1988-12-01

    The "enteque seco" is a disease of calcinosis, i.e., pathological deposition of calcium phosphate in soft tissues, which occurs in grazing cattle in Argentina and is of considerable economic importance. The ingestion of leaves of Solanum malacoxylon has been identified as the cause of the disease. Hypercalcemia and/or hyperphosphatemia and mineralization of the cardiovascular and pulmonary systems are usually seen in bovines or experimental animals exposed to this plant. The symptoms of the disease resemble those of vitamin D intoxication. In agreement with these observations, a glycoside derivative of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the hormonally active form of vitamin D in animals, has been identified as the toxic principle of S. malacoxylon. Glycoside conjugates of its precursors, 25-hydroxyvitamin D3 and vitamin D3, may also be present. Recent studies indicate that the plant factor is modified in the rumen of bovines through cleavage of the glycosidic linkage and further conversion of the released 1,25(OH)2D3 to a more polar metabolite, possibly 1,24,25-trihydroxyvitamin D3. Excess free 1,25(OH)2D3 may alter extracellular and intracellular Ca homeostasis in intoxicated animals through a receptor-mediated mechanism and activation of membrane Ca channels. In addition, 1,24,25(OH)3D3 may potentiate the effects of 1,25(OH)2D3 on intestinal Ca transport. PMID:3077267

  6. REPRODUCTION AND DISTRIBUTION OF FISHES IN A COOLING LAKE: WISCONSIN POWER PLANT IMPACT STUDY

    EPA Science Inventory

    Spatial and temporal patterns during reproduction and early life history of fishes were studied in a manmade cooling lake. Lake Columbia, impounded in 1974, near Portage, Wisconsin, has an area of 190 ha, a mean depth of 2.1 m, and a 15C temperature gradient derived from the ther...

  7. Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

    PubMed

    Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

    2015-08-01

    Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands. PMID:25871977

  8. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  9. Do local adaptation and the reproductive tactic of Atlantic salmon (Salmo salar L.) affect offspring metabolic capacities?

    PubMed

    Rossignol, O; Dodson, J J; Marquilly, C; Guderley, H

    2010-01-01

    Atlantic salmon (Salmo salar L.) is an iteroparous, anadromous species that exhibits some of the greatest within-population variability in size and age at maturity of all vertebrates. In the conditional reproductive strategy of salmonids, the male reproductive tactic expressed is believed to depend on an individual male's status relative to others in the population and therefore depends on his capacity to attain a physiological threshold, the exact nature of which is unknown. Although the threshold is influenced by local biotic and abiotic conditions, it is likely to be under genetic control. Our study examined whether the early growth, muscle metabolic capacities, routine metabolic rate, and spontaneous swimming of salmon alevins reared in laboratory conditions varied with the population of origin, maternal investment, and the paternal reproductive tactic. Our experimental design allowed us to establish that neither the population of origin nor the paternal reproductive tactic influenced the physiological capacities of alevins. The strong influence of the mother on alevin metabolic capacities suggests that the bioenergetic differences in metabolic capacities, realized metabolic rates, and activity levels that could eventually dictate the reproductive tactic of male offspring may originate in maternal effects. PMID:20350165

  10. Weed host specificity of the aphid, Aphis spiraecola: developmental and reproductive performance of aphids in relation to plant growth and leaf chemicals of the Siam weed, Chromolaena odorata.

    PubMed

    Agarwala, B K; Das, Jhuma

    2012-01-01

    Density, distribution, and nutritional quality of plants are the causal basis of host plant selection in aphids. Nutritional qualities of a plant vary according to its growth stage and also in response to seasonal variation. How host plant growth stages shape aphid performance was studied in Aphis spiraecola Patch (Homoptera: Aphididae) on the perennial Siam weed, Chromolaena odorata (L.) King and Robinson (Asterales: Asteraceae). This plant species is the preferred host in the hot and humid tropical parts of northeast and southern India. Variations in developmental and reproductive performances in apterous viviparous female aphids were recorded in relation to differences in leaf chemicals in different growth stages of C. odorata. Aphids reproduced at higher rates in the vegetative stage of C. odorata when developmental time was shortest, and fecundity was higher in a longer reproductive time. Intrinsic rate of increase and net reproductive rate were also recorded to be higher in the vegetative stage of the weed host. In the vegetative stage, leaves contained higher quantity of proteins and nitrogen, which are vital for insect reproduction. Results of this study have demonstrated that A spiraecola showed synchronization of its developmental and reproductive performances to growth stages of C. odorata, which occur in high abundance in the study area. PMID:22950746

  11. Weed Host Specificity of the Aphid, Aphis spiraecola: Developmental and Reproductive Performance of Aphids in Relation to Plant Growth and Leaf Chemicals of the Siam Weed, Chromolaena odorata

    PubMed Central

    Agarwala, B.K.; Das, Jhuma

    2012-01-01

    Density, distribution, and nutritional quality of plants are the causal basis of host plant selection in aphids. Nutritional qualities of a plant vary according to its growth stage and also in response to seasonal variation. How host plant growth stages shape aphid performance was studied in Aphis spiraecola Patch (Homoptera: Aphididae) on the perennial Siam weed, Chromolaena odorata (L.) King and Robinson (Asterales: Asteraceae). This plant species is the preferred host in the hot and humid tropical parts of northeast and southern India. Variations in developmental and reproductive performances in apterous viviparous female aphids were recorded in relation to differences in leaf chemicals in different growth stages of C. odorata. Aphids reproduced at higher rates in the vegetative stage of C. odorata when developmental time was shortest, and fecundity was higher in a longer reproductive time. Intrinsic rate of increase and net reproductive rate were also recorded to be higher in the vegetative stage of the weed host. In the vegetative stage, leaves contained higher quantity of proteins and nitrogen, which are vital for insect reproduction. Results of this study have demonstrated that A spiraecola showed synchronization of its developmental and reproductive performances to growth stages of C. odorata, which occur in high abundance in the study area. PMID:22950746

  12. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant

    PubMed Central

    Scobie, A. R.; Wilcock, C. C.

    2009-01-01

    Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0·25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species. PMID

  13. A Fungal Endosymbiont Affects Host Plant Recruitment Through Seed- and Litter-mediated Mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Many grass species are associated with maternally transmitted fungal endophytes. Increasing evidence shows that endophytes enhance host plant success under varied conditions, yet studies have rarely considered alternative mechanisms whereby these mutualistic symbionts may affect regeneration from...

  14. Reassessment of selected factors affecting siting of Nuclear Power Plants

    SciTech Connect

    Davis, R.E.; Hanson, A.L.; Mubayi, V.; Nourbakhsh, H.P.

    1997-02-01

    Brookhaven National Laboratory has performed a series of probabilistic consequence assessment calculations for nuclear reactor siting. This study takes into account recent insights into severe accident source terms and examines consequences in a risk based format consistent with the quantitative health objectives (QHOs) of the NRC`s Safety Goal Policy. Simplified severe accident source terms developed in this study are based on the risk insights of NUREG-1150. The results of the study indicate that both the quantity of radioactivity released in a severe accident as well as the likelihood of a release are lower than those predicted in earlier studies. The accident risks using the simplified source terms are examined at a series of generic plant sites, that vary in population distribution, meteorological conditions, and exclusion area boundary distances. Sensitivity calculations are performed to evaluate the effects of emergency protective action assumptions on the risk of prompt fatality and latent cancers fatality, and population relocation. The study finds that based on the new source terms the prompt and latent fatality risks at all generic sites meet the QHOs of the NRC`s Safety Goal Policy by margins ranging from one to more than three orders of magnitude. 4 refs., 17 figs., 24 tabs.

  15. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  16. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  17. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  18. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  19. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  20. Nitrogen and water affect direct and indirect plant systemic induced defense in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We tested the affects of nitrogen levels and water availability on the ability of cotton plants to deter feeding by Spodoptera exigua larvae through induction of anti-feedant chemicals by the cotton plant, and to attract the biological control agent, Micropitis crociepes through induction of chemica...

  1. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid source ...

  2. Dehydration-stress affects vegetative reproduction and transcriptome profiles in underground adventitious buds of leafy spurge (Euphorbia esula)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leafy spurge is an invasive perennial weed that infests mainly range, recreational and right-of-way lands in the great plains of the US and Canada. Although spread occurs by both seeds and roots, the perennial nature of leafy spurge is attributed to vegetative reproduction from an abundance of under...

  3. Evaluation of quantitative trait loci affecting intramuscular fat and reproductive traits in pigs using marker-assisted introgression.

    PubMed

    Sato, S; Ohnishi, C; Kikuchi, T; Kohira, K; Egawa, S; Terai, S; Nakamura, T; Arata, S; Komatsuda, A; Uemoto, Y

    2014-12-01

    We investigated the effects of previously identified quantitative trait loci (QTL) in an experimental backcross (BC) between Chinese Meishan pigs and commercial Duroc pigs. We performed marker-assisted introgression of two QTL for intramuscular fat (IMF) content (IMF population) and three QTL for reproductive traits (reproduction population) from a donor Meishan pig into a recipient Duroc pig. At the fourth BC generation of the IMF population and third BC generation of the reproduction population, carrier animals were selected for the production of animals homozygous for the QTL. Our previous studies have shown that the presence of a Meishan allele on the IMF QTL is associated with low IMF values, and the Meishan allele on the reproductive QTL is associated with large litters. In this study, the presence of a Duroc allele at the IMF QTL on SSC9 resulted in a 0.27% increase in IMF (additive effect = 0.27 ± 0.08), whereas the presence of a Meishan allele at the IMF QTL on SSC7 resulted in a 0.34% increase in IMF (additive effect = -0.34 ± 0.09). The presence of the Meishan allele at the IMF QTL on SSC7 thus had the opposite effect to our previous studies, that is, increased IMF. In the reproduction population, we observed no differences between the genotypes of the three QTL in regard to number of corpora lutea or litter size. Marker-assisted introgression at these QTL is thus unlikely to result in an associated increase in litter size. These results show that it is possible to introgress alleles from other breeds into a selection population using molecular markers; any unexpected results might be associated with the genetic background. PMID:25099662

  4. Drought stress affects plant metabolites and herbivore preference but not host location by its parasitoids.

    PubMed

    Weldegergis, Berhane T; Zhu, Feng; Poelman, Erik H; Dicke, Marcel

    2015-03-01

    One of the main abiotic stresses that strongly affects plant survival and the primary cause of crop loss around the world is drought. Drought stress leads to sequential morphological, physiological, biochemical and molecular changes that can have severe effects on plant growth, development and productivity. As a consequence of these changes, the interaction between plants and insects can be altered. Using cultivated Brassica oleracea plants, the parasitoid Microplitis mediator and its herbivorous host Mamestra brassicae, we studied the effect of drought stress on (1) the emission of plant volatile organic compounds (VOCs), (2) plant hormone titres, (3) preference and performance of the herbivore, and (4) preference of the parasitoid. Higher levels of jasmonic acid (JA) and abscisic acid (ABA) were recorded in response to herbivory, but no significant differences were observed for salicylic acid (SA) and indole-3-acetic acid (IAA). Drought significantly impacted SA level and showed a significant interactive effect with herbivory for IAA levels. A total of 55 VOCs were recorded and the difference among the treatments was influenced largely by herbivory, where the emission rate of fatty acid-derived volatiles, nitriles and (E)-4,8-dimethylnona-1,3,7-triene [(E)-DMNT] was enhanced. Mamestra brassicae moths preferred to lay eggs on drought-stressed over control plants; their offspring performed similarly on plants of both treatments. VOCs due to drought did not affect the choice of M. mediator parasitoids. Overall, our study reveals an influence of drought on plant chemistry and insect-plant interactions. PMID:25370387

  5. Widespread seed limitation affects plant density but not population trajectory in the invasive plant Centaurea solstitialis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In some plant populations, the availability of seeds strongly regulates recruitment. However, a scarcity of germination microsites, granivory or density dependent mortality can reduce the number of plants that germinate or survive to flowering. The relative strength of these controls is unknown for ...

  6. Evaluation of non-genetic factors affecting calf growth, reproductive performance and milk yield of traditionally managed Sheko cattle in southwest Ethiopia.

    PubMed

    Bayou, E; Haile, A; Gizaw, S; Mekasha, Y

    2015-01-01

    The study was conducted to estimate calf growth, reproductive performance and milk yield of Ethiopia Sheko cattle and to assess non-genetic factors affecting their performance in their home tract as a step towards designing sustainable cattle conservation and improvement strategy. All the growth traits considered in the study were significantly affected by all non-genetic factors considered except for the fixed effects of Agro ecological zones (AEZs) and season of birth which were not significant for post weaning daily gain. Calving interval (CI) and days open (DO) were significantly influenced by AEZs, season and dam parity. Cows that calved in lowland had shorter CI and DO than cows which calved in midland. Cows that calved in short rainy season had Short CI and DO than those calved during dry season or long rainy season. Cows which calved for the first time had the longest CI and DO from the other parities whereas cows on their fifth parity had the shortest CI and DO. AEZ significantly affected lactation milk yield (LMY) and lactation length (LL), but not significant on daily milk yield (DMY) and 305 days yield (305DY). Season was significant on all milk traits considered except DMY. Parity effect was significant on LMY and 305DY, whereas DMY and LL were not affected. The non-genetic factors had significant effects for all of the reproductive; and many of the growth and milk performance traits considered and hence will need to be considered in cattle breed improvement program. PMID:26543703

  7. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-01-01

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats. PMID:25763628

  8. Climate warming affects biological invasions by shifting interactions of plants and herbivores.

    PubMed

    Lu, Xinmin; Siemann, Evan; Shao, Xu; Wei, Hui; Ding, Jianqing

    2013-08-01

    Plants and herbivorous insects can each be dramatically affected by temperature. Climate warming may impact plant invasion success directly but also indirectly through changes in their natural enemies. To date, however, there are no tests of how climate warming shifts the interactions among invasive plants and their natural enemies to affect invasion success. Field surveys covering the full latitudinal range of invasive Alternanthera philoxeroides in China showed that a beetle introduced for biocontrol was rare or absent at higher latitudes. In contrast, plant cover and mass increased with latitude. In a 2-year field experiment near the northern limit of beetle distribution, we found the beetle sustained populations across years under elevated temperature, dramatically decreasing A. philoxeroides growth, but it failed to overwinter in ambient temperature. Together, these results suggest that warming will allow the natural enemy to expand its range, potentially benefiting biocontrol in regions that are currently too cold for the natural enemy. However, the invader may also expand its range further north in response to warming. In such cases where plants tolerate cold better than their natural enemies, the geographical gap between plant and herbivorous insect ranges may not disappear but will shift to higher latitudes, leading to a new zone of enemy release. Therefore, warming will not only affect plant invasions directly but also drive either enemy release or increase that will result in contrasting effects on invasive plants. The findings are also critical for future management of invasive species under climate change. PMID:23640751

  9. Sexual Reproduction and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  10. Demographic consequences of greater clonal than sexual reproduction in Dicentra canadensis.

    PubMed

    Lin, Chia-Hua; Miriti, Maria N; Goodell, Karen

    2016-06-01

    Clonality is a widespread life history trait in flowering plants that may be essential for population persistence, especially in environments where sexual reproduction is unpredictable. Frequent clonal reproduction, however, could hinder sexual reproduction by spatially aggregating ramets that compete with seedlings and reduce inter-genet pollination. Nevertheless, the role of clonality in relation to variable sexual reproduction in population dynamics is often overlooked. We combined population matrix models and pollination experiments to compare the demographic contributions of clonal and sexual reproduction in three Dicentra canadensis populations, one in a well-forested landscape and two in isolated forest remnants. We constructed stage-based transition matrices from 3 years of census data to evaluate annual population growth rates, λ. We used loop analysis to evaluate the relative contribution of different reproductive pathways to λ. Despite strong temporal and spatial variation in seed set, populations generally showed stable growth rates. Although we detected some pollen limitation of seed set, manipulative pollination treatments did not affect population growth rates. Clonal reproduction contributed significantly more than sexual reproduction to population growth in the forest remnants. Only at the well-forested site did sexual reproduction contribute as much as clonal reproduction to population growth. Flowering plants were more likely to transition to a smaller size class with reduced reproductive potential in the following year than similarly sized nonflowering plants, suggesting energy trade-offs between sexual and clonal reproduction at the individual level. Seed production had negligible effects on growth and tuber production of individual plants. Our results demonstrate that clonal reproduction is vital for population persistence in a system where sexual reproduction is unpredictable. The bias toward clonality may be driven by low fitness returns

  11. Extreme Reproduction and Survival of a True Cliffhanger: The Endangered Plant Borderea chouardii (Dioscoreaceae)

    PubMed Central

    García, María B.; Espadaler, Xavier; Olesen, Jens M.

    2012-01-01

    Cliff sides are extreme habitats, often sheltering a rich and unique flora. One example is the dioecious herb Borderea chouardii (Dioscoreaceae), which is a Tertiary, tropical relict, occurring only on two adjacent vertical cliffs in the world. We studied its reproductive biology, which in some aspects is extreme, especially the unusual double mutualistic role of ants as both pollinators and dispersers. We made a 2-year pollination census and four years of seed-dispersal experiments, recording flower visitors and dispersal rates. Fruit and seed set, self-sowing of seeds, seedling recruitment, and fate of seedlings from seeds sowed by different agents were scored over a period of 17 years. The ants Lasius grandis and L. cinereus were the main pollinators, whereas another ant Pheidole pallidula dispersed seeds. Thus ants functioned as double mutualists. Two thirds of all new seedlings came from self-sown seeds, and 1/3 was dispersed by ants, which gathered the seeds with their oil-rich elaiosome. Gravity played a minor role to dispersal. Both ant dispersal and self-sowing resulted in the same survival rate of seedlings. A double mutualism is a risky reproductive strategy, but B. chouardii buffers that by an unusual long–term demographic stability (some individuals exceed 300 years in lifespan) and its presence in a climatically very stable habitat, inaccessible to large herbivores. Such a combination of traits and habitat properties may explain the persistence of this relict species. PMID:22984539

  12. Influence of relative humidity on direct sulfur dioxide damage to plant sexual reproduction

    SciTech Connect

    Murdy, W.H.; Ragsdale, H.L.

    1980-07-01

    Results of in vivo experiments with Geranium carolinianum L. showed that sulfur dioxide (SO/sub 2/) damaged sexual reproduction (in terms of decreased seed set) when relative humdity (RH) was 80% or above but not when RH was 70% or below. Relative humidity alone, if 80% or higher, damaged sexual reproduction; the addition of SO/sub 2/ increased the damage. A high SO/sub 2/ dosage of 1.5 ppM/7 hours at 50% RH caused leaf injury, but decreased percent seed set <5%, whereas a low SO/sub 2/ dosage of 0.2 ppM/7 hours at 90% RH decreased percent seed set by 32% without visible leaf injury. At an SO/sub 2/ dosage of 0.4 ppM/7 hours administered during anthesis, percent seed set was virtually identical with the control at 70% RH, 35% below the control at 80% RH, and 68% below the control at 90% RH.

  13. Reproductive isolation between Stigmaeopsis celarius and its sibling species sympatrically inhabiting bamboo (Pleioblastus spp.) plants.

    PubMed

    Chae, Younghae; Yokoyama, Nanako; Ito, Katsura; Fukuda, Tatsuya; Arakawa, Ryo; Zhang, Yan-Xuan; Saito, Yutaka

    2015-05-01

    Stigmaeopsis celarius Banks (hereafter Sc) is a spider mite living and feeding on the leaves of various bamboo species such as Moso bamboo [Phyllostachys edulis (=P. pubescens)] and Pleioblastus spp. (Poaceae). A previous phylogenetic study revealed a cryptic, phylogenetic sister species to Sc (hereafter Ss). Although its life type appears to be similar to that of Sc, individuals of Ss make much smaller nests compared with Sc, and the nests have been found mostly on Nezasa bamboo (Pleioblastus argenteostriatus). To investigate whether Sc and Ss are reproductively isolated, we explored their populations in southwestern Japan, and crossed them to examine mating behaviors and fertilization success. Field surveys revealed that the nests of these two species occur on the same leaves and, thus, the individuals of these species may make frequent contact. Reciprocal crosses suggested that the two species are reproductively isolated. Though Sc males have tried to mate with Ss females, copulation seldom occurred because of their long opisthosoma (hind body), which prevented the insertion of the aedeagus into the genitalia of Ss females. In contrast, most Ss males ignored Sc females, and eggs were not fertilized even in the few cases where copulation appeared to occur. These results suggest that strong selection pressure is imposed on body length to prevent interspecific hybridization in the contact area of these species. PMID:25433761

  14. Pollination, mating and reproductive fitness in a plant population with bimodal floral-tube length.

    PubMed

    Anderson, B; Pauw, A; Cole, W W; Barrett, S C H

    2016-08-01

    Mating patterns and natural selection play important roles in determining whether genetic polymorphisms are maintained or lost. Here, we document an atypical population of Lapeirousia anceps (Iridaceae) with a bimodal distribution of floral-tube length and investigate the reproductive mechanisms associated with this pattern of variation. Flowers were visited exclusively by the long-proboscid fly Moegistorhynchus longirostris (Nemestrinidae), which exhibited a unimodal distribution of proboscis length and displayed a preference for long-tubed phenotypes. Despite being visited by a single pollinator species, allozyme markers revealed significant genetic differentiation between open-pollinated progeny of long- and short-tubed phenotypes suggesting mating barriers between them. We obtained direct evidence for mating barriers between the floral-tube phenotypes through observations of pollinator foraging, controlled hand pollinations and measurements of pollen competition and seed set. Intermediate tube-length phenotypes produced fewer seeds in the field than either long- or short-tubed phenotypes. Although floral-tube length bimodality may not be a stable state over long timescales, reproductive barriers to mating and low 'hybrid' fitness have the potential to contribute to the maintenance of this state in the short term. PMID:27206242

  15. Moisture source and diet affect development and reproduction of Orius thripoborus and Orius naivashae, two predatory anthocorids from Southern Africa.

    PubMed

    Bonte, Jochem; Vangansbeke, Dominiek; Maes, Sara; Bonte, Maarten; Conlong, Des; De Clercq, Patrick

    2012-01-01

    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed. PMID:22935002

  16. Moisture Source and Diet affect Development and Reproduction of Orius thripoborus and Orius naivashae, two Predatory Anthocorids from Southern Africa

    PubMed Central

    Bonte, Jochem; Vangansbeke, Dominiek; Maes, Sara; Bonte, Maarten; Conlong, Des; Clercq, Patrick De

    2012-01-01

    The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed. PMID:22935002

  17. Negative effects of fluoranthene on the ecophysiology of tomato plants (Lycopersicon esculentum Mill) Fluoranthene mists negatively affected tomato plants.

    PubMed

    Oguntimehin, Ilemobayo; Eissa, Fawzy; Sakugawa, Hiroshi

    2010-02-01

    Cherry tomato plants (Lycopersicon esculentum Mill) were sprayed with fluoranthene and mixture of fluoranthene and mannitol solutions for 30d. The exposure was carried out in growth chambers in field conditions, and the air was filtered through charcoal filters to remove atmospheric contaminants. Plants were sprayed with 10microM fluoranthene as mist until they reached the fruiting stage, and the eco-physiological parameters were measured to determine the effects of the treatments. We measured CO(2) uptake and water vapour exchange, chlorophyll fluorescence, leaf pigment contents, visual symptoms and biomass allocation. Fluoranthene which was deposited as mist onto leaves negatively affected both growth and the quality of tomato plants, while other treatments did not. The photosynthetic rate measured at saturated irradiance was approximately 37% lower in fluoranthene-treated plants compared with the control group. Other variables, such as stomata conductance, the photochemical efficiency of PSII in the dark, Chl a, Chl b, and the total chlorophyll contents of the tomato leaves were significantly reduced in the fluoranthene-treated plants. Tomato plants treated with fluoranthene showed severe visible injury symptoms on the foliage during the exposure period. Mannitol (a reactive oxygen scavenger) mitigated effects of fluoranthene; thus, reactive oxygen species generated through fluoranthene may be responsible for the damaged tomato plants. It is possible for fluoranthene to decrease the aesthetic and hence the economic value of this valuable crop plant. PMID:20006894

  18. Flavonoid accumulation in Arabidopsis repressed in lignin synthesis affects auxin transport and plant growth.

    PubMed

    Besseau, Sébastien; Hoffmann, Laurent; Geoffroy, Pierrette; Lapierre, Catherine; Pollet, Brigitte; Legrand, Michel

    2007-01-01

    In Arabidopsis thaliana, silencing of hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT), a lignin biosynthetic gene, results in a strong reduction of plant growth. We show that, in HCT-silenced plants, lignin synthesis repression leads to the redirection of the metabolic flux into flavonoids through chalcone synthase activity. Several flavonol glycosides and acylated anthocyanin were shown to accumulate in higher amounts in silenced plants. By contrast, sinapoylmalate levels were barely affected, suggesting that the synthesis of that phenylpropanoid compound might be HCT-independent. The growth phenotype of HCT-silenced plants was shown to be controlled by light and to depend on chalcone synthase expression. Histochemical analysis of silenced stem tissues demonstrated altered tracheary elements. The level of plant growth reduction of HCT-deficient plants was correlated with the inhibition of auxin transport. Suppression of flavonoid accumulation by chalcone synthase repression in HCT-deficient plants restored normal auxin transport and wild-type plant growth. By contrast, the lignin structure of the plants simultaneously repressed for HCT and chalcone synthase remained as severely altered as in HCT-silenced plants, with a large predominance of nonmethoxylated H units. These data demonstrate that the reduced size phenotype of HCT-silenced plants is not due to the alteration of lignin synthesis but to flavonoid accumulation. PMID:17237352

  19. Selective Pressure along a Latitudinal Gradient Affects Subindividual Variation in Plants

    PubMed Central

    Sobral, Mar; Guitián, José; Guitián, Pablo; Larrinaga, Asier R.

    2013-01-01

    Individual plants produce repeated structures such as leaves, flowers or fruits, which, although belonging to the same genotype, are not phenotypically identical. Such subindividual variation reflects the potential of individual genotypes to vary with micro-environmental conditions. Furthermore, variation in organ traits imposes costs to foraging animals such as time, energy and increased predation risk. Therefore, animals that interact with plants may respond to this variation and affect plant fitness. Thus, phenotypic variation within an individual plant could be, in part, an adaptive trait. Here we investigated this idea and we found that subindividual variation of fruit size of Crataegus monogyna, in different populations throughout the latitudinal gradient in Europe, was explained at some extent by the selective pressures exerted by seed-dispersing birds. These findings support the hypothesis that within-individual variation in plants is an adaptive trait selected by interacting animals which may have important implications for plant evolution. PMID:24069297

  20. EFFECTS OF SINGLE, BINARY AND TERTIARY COMBINATIONS WITH Jatropha gossypifolia AND OTHER PLANT-DERIVED MOLLUSCICIDES ON REPRODUCTION AND SURVIVAL OF THE SNAIL Lymnaea acuminata

    PubMed Central

    Yadav, Ram P.; Singh, Ajay

    2014-01-01

    The effect of sub-lethal doses (40% and 80% of LC50/24h) of plant derived molluscicides of singly, binary (1:1) and tertiary (1:1:1) combinations of the Rutin, Ellagic acid, Betulin and taraxerol with J. gossypifolia latex, leaf and stem bark powder extracts and their active component on the reproduction of freshwater snail Lymnaea acuminata have been studied. It was observed that the J. gossypifolia latex, stem bark, individual leaf and their combinations with other plant derived active molluscicidal components caused a significant reduction in fecundity, hatchability and survival of young snails. It is believed that sub-lethal exposure of these molluscicides on snail reproduction is a complex process involving more than one factor in reducing the reproductive capacity. PMID:25229223

  1. Effects of single, binary and tertiary combinations with Jatropha gossypifolia and other plant-derived molluscicides on reproduction and survival of the snail Lymnaea acuminata.

    PubMed

    Yadav, Ram P; Singh, Ajay

    2014-01-01

    The effect of sub-lethal doses (40% and 80% of LC(50)/24h) of plant derived molluscicides of singly, binary (1:1) and tertiary (1:1:1) combinations of the Rutin, Ellagic acid, Betulin and taraxerol with J. gossypifolia latex, leaf and stem bark powder extracts and their active component on the reproduction of freshwater snail Lymnaea acuminata have been studied. It was observed that the J. gossypifolia latex, stem bark, individual leaf and their combinations with other plant derived active molluscicidal components caused a significant reduction in fecundity, hatchability and survival of young snails. It is believed that sub-lethal exposure of these molluscicides on snail reproduction is a complex process involving more than one factor in reducing the reproductive capacity. PMID:25229223

  2. Plant diversity and functional groups affect Si and Ca pools in aboveground biomass of grassland systems.

    PubMed

    Schaller, Jörg; Roscher, Christiane; Hillebrand, Helmut; Weigelt, Alexandra; Oelmann, Yvonne; Wilcke, Wolfgang; Ebeling, Anne; Weisser, Wolfgang W

    2016-09-01

    Plant diversity is an important driver of nitrogen and phosphorus stocks in aboveground plant biomass of grassland ecosystems, but plant diversity effects on other elements also important for plant growth are less understood. We tested whether plant species richness, functional group richness or the presence/absence of particular plant functional groups influences the Si and Ca concentrations (mmol g(-1)) and stocks (mmol m(-2)) in aboveground plant biomass in a large grassland biodiversity experiment (Jena Experiment). In the experiment including 60 temperate grassland species, plant diversity was manipulated as sown species richness (1, 2, 4, 8, 16) and richness and identity of plant functional groups (1-4; grasses, small herbs, tall herbs, legumes). We found positive species richness effects on Si as well as Ca stocks that were attributable to increased biomass production. The presence of particular functional groups was the most important factor explaining variation in aboveground Si and Ca stocks (mmol m(-2)). Grass presence increased the Si stocks by 140 % and legume presence increased the Ca stock by 230 %. Both the presence of specific plant functional groups and species diversity altered Si and Ca stocks, whereas Si and Ca concentration were affected mostly by the presence of specific plant functional groups. However, we found a negative effect of species diversity on Si and Ca accumulation, by calculating the deviation between mixtures and mixture biomass proportions, but in monoculture concentrations. These changes may in turn affect ecosystem processes such as plant litter decomposition and nutrient cycling in grasslands. PMID:27164912

  3. Assessment of wastewater treatment plant effluent on fish reproduction utilizing the adverse outcome pathway conceptual framework

    EPA Science Inventory

    Wastewater treatment plant (WWTP) effluents are a known contributor of chemical mixture inputs into the environment. Whole effluent testing guidelines were developed to screen these complex mixtures for acute toxicity. However, efficient and cost-effective approaches for screenin...

  4. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  5. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci.

    PubMed

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles-especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  6. Effects of Computer-Assisted Instruction (CAI) on 11th Graders' Attitudes to Biology and CAI and Understanding of Reproduction in Plants and Animals.

    ERIC Educational Resources Information Center

    Soyibo, Kola; Hudson, Ann

    2000-01-01

    Investigates whether the use of the combination of lecture, discussion, and computer-assisted instruction (CAI) significantly improved students' attitudes toward biology and their understanding of reproduction in plants and animals. Studies grade 11 Jamaican female students (n=77) from two traditional high schools in Kingston. (Contains 19…

  7. The Effects of Concept and Vee Mappings under Three Learning Modes on Jamaican Eighth Graders' Knowledge of Nutrition and Plant Reproduction

    ERIC Educational Resources Information Center

    Ugwu, Okechukwu; Soyibo, Kola

    2004-01-01

    The first objective of this study was to investigate if the experimental students' post-test knowledge of nutrition and plant reproduction would be improved more significantly than that of their control group counterparts based on their treatment, attitudes to science, self-esteem, gender and socio-economic background. Treatment involved teaching…

  8. How Does Religious Affiliation Affect Women’s Attitudes Toward Reproductive Health Policy? Implications for the Affordable Care Act

    PubMed Central

    Patton, Elizabeth W.; Hall, Kelli Stidham; Dalton, Vanessa K.

    2015-01-01

    Structured Abstract Background Supreme Court cases challenging the Affordable Care Act (ACA) mandate for employer-provided reproductive health care have focused on religiously based opposition to coverage. Little is known about women’s perspectives on such reproductive health policies. Study Design Data were drawn from the Women’s Health Care Experiences and Preferences survey, a randomly selected, nationally representative sample of 1078 US women age 18–55. We examined associations between religious affiliation and attitudes toward employer-provided insurance coverage of contraception and abortion services, and the exclusion of religious institutions from this coverage. We used chi-square and multivariable logistic regression for analysis. Results Respondents self-identified as Baptist (18%), Protestant (Other Mainline, 17%), Catholic (17%), Other Christian (20%), Religious, Non-Christian (7%) or no affiliation (21%). Religious affiliation was associated with proportions of agreement for contraception (p = 0.03), abortion (p <0.01), and religious exclusion (p <0.01) policies. In multivariable models, differences in the odds of agreement varied across religious affiliations and frequency of service attendance. For example, compared to non-affiliated women, Baptists and Other Nondenominational Christians (but not Catholics) had lower odds of agreement with employer coverage of contraception (OR 0.63, 95% CI 0.4-0.1 and OR 0.57, CI 0.4–0.9, respectively); women who attended services weekly or more than weekly had lower odds of agreement (OR 0.53, 95% CI 0.3–0.8 and OR 0.33, CI 0.2–0.6, respectively), compared to less frequent attenders. Conclusions Recent religiously motivated legal challenges to employer-provided reproductive health care coverage may not represent the attitudes of many religious women. PMID:25727764

  9. High Temperatures Result in Smaller Nurseries which Lower Reproduction of Pollinators and Parasites in a Brood Site Pollination Mutualism

    PubMed Central

    Krishnan, Anusha; Pramanik, Gautam Kumar; Revadi, Santosh V.; Venkateswaran, Vignesh; Borges, Renee M.

    2014-01-01

    In a nursery pollination mutualism, we asked whether environmental factors affected reproduction of mutualistic pollinators, non-mutualistic parasites and seed production via seasonal changes in plant traits such as inflorescence size and within-tree reproductive phenology. We examined seasonal variation in reproduction in Ficus racemosa community members that utilise enclosed inflorescences called syconia as nurseries. Temperature, relative humidity and rainfall defined four seasons: winter; hot days, cold nights; summer and wet seasons. Syconium volumes were highest in winter and lowest in summer, and affected syconium contents positively across all seasons. Greater transpiration from the nurseries was possibly responsible for smaller syconia in summer. The 3–5°C increase in mean temperatures between the cooler seasons and summer reduced fig wasp reproduction and increased seed production nearly two-fold. Yet, seed and pollinator progeny production were never negatively related in any season confirming the mutualistic fig–pollinator association across seasons. Non-pollinator parasites affected seed production negatively in some seasons, but had a surprisingly positive relationship with pollinators in most seasons. While within-tree reproductive phenology did not vary across seasons, its effect on syconium inhabitants varied with season. In all seasons, within-tree reproductive asynchrony affected parasite reproduction negatively, whereas it had a positive effect on pollinator reproduction in winter and a negative effect in summer. Seasonally variable syconium volumes probably caused the differential effect of within-tree reproductive phenology on pollinator reproduction. Within-tree reproductive asynchrony itself was positively affected by intra-tree variation in syconium contents and volume, creating a unique feedback loop which varied across seasons. Therefore, nursery size affected fig wasp reproduction, seed production and within-tree reproductive

  10. Deviation from niche optima affects the nature of plant-plant interactions along a soil acidity gradient.

    PubMed

    He, Lei; Cheng, Lulu; Hu, Liangliang; Tang, Jianjun; Chen, Xin

    2016-01-01

    There is increasing recognition of the importance of niche optima in the shift of plant-plant interactions along environmental stress gradients. Here, we investigate whether deviation from niche optima would affect the outcome of plant-plant interactions along a soil acidity gradient (pH = 3.1, 4.1, 5.5 and 6.1) in a pot experiment. We used the acid-tolerant species Lespedeza formosa Koehne as the neighbouring plant and the acid-tolerant species Indigofera pseudotinctoria Mats. or acid-sensitive species Medicago sativa L. as the target plants. Biomass was used to determine the optimal pH and to calculate the relative interaction index (RII). We found that the relationships between RII and the deviation of soil pH from the target's optimal pH were linear for both target species. Both targets were increasingly promoted by the neighbour as pH values deviated from their optima; neighbours benefitted target plants by promoting soil symbiotic arbuscular mycorrhizal fungi, increasing soil organic matter or reducing soil exchangeable aluminium. Our results suggest that the shape of the curve describing the relationship between soil pH and facilitation/competition depends on the soil pH optima of the particular species. PMID:26740568

  11. Pollinator limitation on reproductive success in Iris tuberosa.

    PubMed

    Pellegrino, Giuseppe

    2014-01-01

    Variation in plant and floral size can have conflicting effects on pollination and fruit production in flowering plants. This research examines the contributions of plant height, flower size and pollinator visitation to reproductive success in four populations of Iris tuberosa. The plants were pollinated exclusively by hymenopteran species, primarily during sunny days. Pollination supplementation increased the proportion of flowers that matured into fruit, with 95 % fruit set for hand-pollinated compared with 74.15 % for naturally pollinated flowers. The pollinator visitation rate and the proportion of fruit produced were not significantly different between tall and short plants or between small and large flowers. Furthermore, the increase in plant size and floral display did not increase the frequency of pollinator visitations and so did not increase the fruit set. Thus, despite the widespread effects of flowering plant size on pollinator attraction and plant reproduction in other species, these effects are lacking in I. tuberosa. This study quantifies the role of pollinators in the reproductive success of I. tuberosa. Pollinators visited tall/short plants and large/small flowers in equal proportion, suggesting that plant and floral display size do not affect pollinator attraction and reproductive success in I. tuberosa. These results suggest that sexual reproduction of I. tuberosa is fairly limited by pollinators and not by resource limitation. PMID:25527476

  12. Florivore impacts on plant reproductive success and pollinator mortality in an obligate pollination mutualism.

    PubMed

    Althoff, David M; Xiao, Wei; Sumoski, Sarah; Segraves, Kari A

    2013-12-01

    Florivores are present in many pollination systems and can have direct and indirect effects on both plants and pollinators. Although the impact of florivores are commonly examined in facultative pollination mutualisms, their effects on obligate mutualism remain relatively unstudied. Here, we used experimental manipulations and surveys of naturally occurring plants to assess the effect of florivory on the obligate pollination mutualism between yuccas and yucca moths. Yucca filamentosa (Agavaceae) is pollinated by the moth Tegeticula cassandra (Lepidoptera: Prodoxidae), and the mutualism also attracts two florivores: a generalist, the leaf-footed bug Leptoglossus phyllopus (Hemiptera: Coreidae), and a specialist, the beetle Hymenorus densus (Coleoptera: Tenebrionidae). Experimental manipulations of leaf-footed bug densities on side branches of Y. filamentosa inflorescences demonstrated that feeding causes floral abscission but does not reduce pollen or seed production in the remaining flowers. Similar to the leaf-footed bugs, experimental manipulations of beetle densities within individual flowers demonstrated that beetle feeding also causes floral abscission, but, in addition, the beetles also cause a significant reduction in pollen availability. Path analyses of phenotypic selection based on surveys of naturally occurring plants revealed temporal variation in the plant traits important to plant fitness and the effects of the florivores on fitness. Leaf-footed bugs negatively impacted fitness when fewer plants were flowering and leaf-footed bug density was high, whereas beetles had a positive effect on fitness when there were many plants flowering and their densities were low. This positive effect was likely due to adult beetles consuming yucca moth eggs while having a negligible effect on floral abscission. Together, the actions of both florivores either augmented the relationship of plant traits and fitness or slightly weakened the relationship. Overall, the

  13. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  14. Accumulation of heavy metals in sunflower and sorghum plants affected by the Guadiamar spill.

    PubMed

    Murillo, J M; Marañón, T; Cabrera, F; López, R

    1999-12-01

    The collapse of a pyrite-mining, tailing dam on 25 April 1998 contaminated approximately 2000 ha of croplands along the Agrio and Guadiamar river valleys in southern Spain. This paper reports the accumulation of chemical elements in soil and in two crops--sunflower and sorghum--affected by the spill. Total concentrations of As, Bi, Cd, Cu, Mn, Pb, Sb, Tl and Zn in spill-affected soils were greater than in adjacent, unaffected soils. Leaves of spill-affected crop plants had higher nutrient (K, Ca and Mg for sunflower and N and K for sorghum) concentrations than controls, indicating a 'fertilising' effect caused by the sludge. Seeds of spill-affected sunflower plants did accumulate more As, Cd, Cu and Zn than controls, but values were below toxic levels. Leaves of sorghum plants accumulated more As, Bi, Cd, Mn, Pb, Tl and Zn than controls, but these values were also below toxic levels for livestock consumption. In general, none of the heavy metals studied in both crops reached either phytotoxic or toxic levels for humans or livestock. Nevertheless, a continuous monitoring of heavy metal accumulation in soil and plants must be established in the spill-affected area. PMID:10635586

  15. Neonatal exposure to 17α-ethynyl estradiol affects ovarian gene expression and disrupts reproductive cycles in female rats.

    PubMed

    Nozawa, Kaori; Nagaoka, Kentaro; Zhang, Haolin; Usuda, Kento; Okazaki, Sachiko; Taya, Kazuyoshi; Yoshida, Midori; Watanabe, Gen

    2014-07-01

    Neonatal exposure to synthetic estrogen causes delayed reproductive dysfunction in female rats. Exposure to 17α-ethynyl estradiol (EE, low: 20 and high: 2000 μg/kg) induced an abnormal estrous cycle during PND171-190 in low-dose and PND126-145 in high-dose group. At PND90 within normal estrous cycle, high-dose animals showed lack of LH surge and low of ovarian hormones in serum level. Gene expression analysis demonstrated that level of mRNA encoding luteinizing hormone/chorionic gonadotropin receptor (LHCGR) was higher in EE-treated ovaries than in control ovaries, and LHCGR protein colocalized with apoptosis-related proteins in the interstitial area of the ovary. At PND1, ovarian LHCGR mRNA levels were higher in EE-treated rats than in control rats, and direct induction of LHCGR expression by EE was observed in vitro. Our results indicate that neonatal exposure to EE induces irregular LHCGR expression in the immature ovary, which may influence the occurrence of delayed reproductive dysfunction in adult animals. PMID:24632129

  16. A CURLY LEAF homologue controls both vegetative and reproductive development of tomato plants.

    PubMed

    Boureau, L; How-Kit, A; Teyssier, E; Drevensek, S; Rainieri, M; Joubès, J; Stammitti, L; Pribat, A; Bowler, C; Hong, Y; Gallusci, P

    2016-03-01

    The Enhancer of Zeste Polycomb group proteins, which are encoded by a small gene family in Arabidopsis thaliana, participate to the control of plant development. In the tomato (Solanum lycopersicum), these proteins are encoded by three genes (SlEZ1, SlEZ2 and SlEZ3) that display specific expression profiles. Using a gene specific RNAi strategy, we demonstrate that repression of SlEZ2 correlates with a general reduction of H3K27me3 levels, indicating that SlEZ2 is part of an active PRC2 complex. Reduction of SlEZ2 gene expression impacts the vegetative development of tomato plants, consistent with SlEZ2 having retained at least some of the functions of the Arabidopsis CURLY LEAF (CLF) protein. Notwithstanding, we observed significant differences between transgenic SlEZ2 RNAi tomato plants and Arabidopsis clf mutants. First, we found that reduced SlEZ2 expression has dramatic effects on tomato fruit development and ripening, functions not described in Arabidopsis for the CLF protein. In addition, repression of SlEZ2 has no significant effect on the flowering time or the control of flower organ identity, in contrast to the Arabidopsis clf mutation. Taken together, our results are consistent with a diversification of the function of CLF orthologues in plants, and indicate that although partly conserved amongst plants, the function of EZ proteins need to be newly investigated for non-model plants because they might have been recruited to specific developmental processes. PMID:26846417

  17. Nest-site selection and reproductive success of greater sage-grouse in a fire-affected habitat of northwestern Nevada

    USGS Publications Warehouse

    Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

    2015-01-01

    Identifying links between micro-habitat selection and wildlife reproduction is imperative to population persistence and recovery. This information is particularly important for landscape species such as greater sage-grouse (Centrocercus urophasianus; sage-grouse). Although this species has been widely studied, because environmental factors can affect sage-grouse populations, local and regional studies are crucial for developing viable conservation strategies. We studied the habitat-use patterns of 71 radio-marked sage-grouse inhabiting an area affected by wildfire in the Virginia Mountains of northwestern Nevada during 2009–2011 to determine the effect of micro-habitat attributes on reproductive success. We measured standard vegetation parameters at nest and random sites using a multi-scale approach (range = 0.01–15,527 ha). We used an information-theoretic modeling approach to identify environmental factors influencing nest-site selection and survival, and determine whether nest survival was a function of resource selection. Sage-grouse selected micro-sites with greater shrub canopy cover and less cheatgrass (Bromus tectorum) cover than random sites. Total shrub canopy, including sagebrush (Artemisia spp.) and other shrub species, at small spatial scales (0.8 ha and 3.1 ha) was the single contributing selection factor to higher nest survival. These results indicate that reducing the risk of wildfire to maintain important sagebrush habitats could be emphasized in sage-grouse conservation strategies in Nevada. Managers may seek to mitigate the influx of annual grass invasion by preserving large intact sagebrush-dominated stands with a mixture of other shrub species. For this area of Nevada, the results suggest that ≥40% total shrub canopy cover in sage-grouse nesting areas could yield improved reproductive success. 

  18. Ozone affects growth and development of Pieris brassicae on the wild host plant Brassica nigra.

    PubMed

    Khaling, Eliezer; Papazian, Stefano; Poelman, Erik H; Holopainen, Jarmo K; Albrectsen, Benedicte R; Blande, James D

    2015-04-01

    When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools. PMID:25645061

  19. Fusarium Oxysporum Volatiles Enhance Plant Growth Via Affecting Auxin Transport and Signaling

    PubMed Central

    Bitas, Vasileios; McCartney, Nathaniel; Li, Ningxiao; Demers, Jill; Kim, Jung-Eun; Kim, Hye-Seon; Brown, Kathleen M.; Kang, Seogchan

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption. PMID:26617587

  20. Plant volatiles induced by herbivore egg deposition affect insects of different trophic levels.

    PubMed

    Fatouros, Nina E; Lucas-Barbosa, Dani; Weldegergis, Berhane T; Pashalidou, Foteini G; van Loon, Joop J A; Dicke, Marcel; Harvey, Jeffrey A; Gols, Rieta; Huigens, Martinus E

    2012-01-01

    Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant's volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels. PMID:22912893

  1. Incest versus abstinence: reproductive trade-offs between mate limitation and progeny fitness in a self-incompatible invasive plant.

    PubMed

    Pierson, Jennifer C; Swain, Stephen M; Young, Andrew G

    2013-12-01

    Plant mating systems represent an evolutionary and ecological trade-off between reproductive assurance through selfing and maximizing progeny fitness through outbreeding. However, many plants with sporophytic self-incompatibility systems exhibit dominance interactions at the S-locus that allow biparental inbreeding, thereby facilitating mating between individuals that share alleles at the S-locus. We investigated this trade-off by estimating mate availability and biparental inbreeding depression in wild radish from five different populations across Australia. We found dominance interactions among S-alleles increased mate availability relative to estimates based on individuals that did not share S-alleles. Twelve of the sixteen fitness variables were significantly reduced by inbreeding. For all the three life-history phases evaluated, self-fertilized offspring suffered a greater than 50% reduction in fitness, while full-sib and half-sib offspring suffered a less than 50% reduction in fitness. Theory indicates that fitness costs greater than 50% can result in an evolutionary trajectory toward a stable state of self-incompatibility (SI). This study suggests that dominance interactions at the S-locus provide a possible third stable state between SI and SC where biparental inbreeding increases mate availability with relatively minor fitness costs. This strategy allows weeds to establish in new environments while maintaining a functional SI system. PMID:24455137

  2. Dormancy regulation in reproductive structures of weedy plants; a comparison between seeds and vegetative buds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dormancy in seeds and vegetative buds is one of the key characteristics which allow weedy plants to escape conventional chemical, cultural, mechanical, and bio-control measures currently available to weed managers. Identifying genetic and physiological targets that regulate dormancy induction and re...

  3. An Introduction to the Sexual Reproduction of Flowering Plants. Ornamental Horticulture I, Lesson Plan No. 5.

    ERIC Educational Resources Information Center

    Ideoka, Keith

    Developed as part of a 90-hour high school course in ornamental horticulture, this 50-minute lesson plan is designed to explain the process of pollination and fertilization of flowering plants. The lesson plan begins with information on the course for which the lesson was designed; equipment and audio-visual aids needed; required student…

  4. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent reports of global declines in pollinator species imply an urgent need to assess native pollinator population sizes and density dependent benefits for linked plants. Here, we estimated effective population sizes (Ne) of four native bumblebee species, Bombus balteatus, B. flavifrons, B. bifariu...

  5. Quantifying the effects of ozone on plant reproductive growth and development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone is a harmful air pollutant that can negatively impact plant growth and development. Current ozone concentrations negatively impact forest productivity and crop yields, and future ozone concentrations will increase if current emission rates continue. However, the specific effects o...

  6. Food availability and reproduction affects lipid and fatty acid composition of the brown mussel, Perna perna, raised in suspension culture.

    PubMed

    Narváez, Mirle; Freites, L; Guevara, M; Mendoza, J; Guderley, H; Lodeiros, C J; Salazar, G

    2008-02-01

    We examined the influence of the reproductive cycle and environmental factors on variations of the condition index (CI), tissue dry mass, shell size, total lipid content, and relative percent of fatty acids in the mussel, Perna perna. Spat or juveniles were reared to commercial size (70 mm) in suspension culture in the Golfo de Cariaco, Venezuela between May and October 2004. The dry mass of soft tissues and shell, a visual assessment of gonadal status and the organism lipid profile were established every fortnight. In parallel, we measured the environmental conditions, following chlorophyll a, salinity, temperature and seston levels. After an initial decrease, the CI rose and remained high until August after which it decreased continuously until October. Total lipid values also decreased initially, after which they showed two periods of rapid recuperation and depletion, the first between May and August and the second between August and October. Similar tendencies were noted in the fatty acids, C18:3n-3, C18:4n-3 and C22:6n-3. Correlation analysis found no significant relationships between environmental parameters and the variations in total lipids. However, significant correlations were noted between fatty acids and specific environmental parameters. In particular, temperature was inversely correlated with C14:0, C16:1n-7, C18:0, C18:1n-9 and 20:5n-3. Chlorophyll a was positively correlated with C14:0, C16:1n-7, C18:1n-7, C18:4n-3 and 20:4n-6. On the other hand, gametogenesis had an effect on C14:0, C16:1n-7, C18:1n-9 and C18:1n-7, while spawned and gonadal regression states had an effect on fatty acid 20:4n-6. Temperature and chlorophyll a levels strongly influenced the proportion of mussels spawning, suggesting that their influence upon lipid composition may be secondary to their impact upon reproduction. Despite the thermal stability of this tropical system, the lipid composition of mussels changed markedly during the study, reflecting the central role of diet

  7. Targeted disruption of the mouse prosaposin gene affects the development of the prostate gland and other male reproductive organs.

    PubMed

    Morales, C R; Zhao, Q; El-Alfy, M; Suzuki, K

    2000-01-01

    The prosaposin gene encodes a 65-70 kilodalton (kd) protein, which is secreted or targeted to lysosomes. In lysosomes, prosaposin is the precursor of 4 activator proteins, designated saposins A, B, C, and D, which promote by acidic hydrolases, the degradation of glycosphingolipids with short oligosaccharide chains. Mutations of the prosaposin gene have been linked to several lysosomal storage disorders. An animal model was recently developed by creating a null allele in embryonic stem cells through gene targeting in order to investigate the phenotypic diversity of prosaposin mutations, the involvement of this protein in lysosomal storage diseases, and to develop potential therapeutic approaches. Mutant homozygous mice die at 35-40 days of age and neurological disorders contribute to their early death. Secreted prosaposin is present in milk and in cerebrospinal and seminal fluids. In the nervous system, prosaposin exhibits a trophic activity. Examination of reproduc-tive organs in homozygous mutant males shows several abnormalities such as a decrease in testis size with reduced spermiogenesis, and an involution of the prostate, seminal vesicle, and epididymis, although levels of testosterone in blood remain normal. In the prostate of homozygous mutants, only basal cells appear to be present, whereas secretory cells are absent. The epithelia in efferent ducts is formed by ciliated cells, whereas heterozygotes exhibit a majority of nonciliated cells. Our data indicate that prosaposin is involved in the development and maintenance of male reproductive organs. In prostatic epithelium, targeted disruption of the prosaposin gene appears to inactivate the mitogen-activated protein kinase pathway and to interfere with differentiation of secretory cells. PMID:11105903

  8. The sleeping beauty: how reproductive diapause affects hormone signaling, metabolism, immune response and somatic maintenance in Drosophila melanogaster.

    PubMed

    Kubrak, Olga I; Kučerová, Lucie; Theopold, Ulrich; Nässel, Dick R

    2014-01-01

    Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation. We induced diapause in D. melanogaster and monitored effects over 12 weeks on dynamics of ovary development, carbohydrate and lipid metabolism, as well as expression of genes involved in endocrine signaling, metabolism and innate immunity. During diapause food intake diminishes drastically, but circulating and stored carbohydrates and lipids are elevated. Gene transcripts of glucagon- and insulin-like peptides increase, and expression of several target genes of these peptides also change. Four key genes in innate immunity can be induced by infection in diapausing flies, and two of these, drosomycin and cecropin A1, are upregulated by diapause independently of infection. Diapausing flies display very low mortality, extended lifespan and decreased aging of the intestinal epithelium. Many phenotypes induced by diapause are reversed after one week of recovery from diapause conditions. Furthermore, mutant flies lacking specific insulin-like peptides (dilp5 and dilp2-3) display increased diapause incidence. Our study provides a first comprehensive characterization of reproductive diapause in D. melanogaster, and evidence that glucagon- and insulin-like signaling are among the key regulators of the altered physiology during this dormancy. PMID:25393614

  9. The Sleeping Beauty: How Reproductive Diapause Affects Hormone Signaling, Metabolism, Immune Response and Somatic Maintenance in Drosophila melanogaster

    PubMed Central

    Kubrak, Olga I.; Kučerová, Lucie; Theopold, Ulrich; Nässel, Dick R.

    2014-01-01

    Some organisms can adapt to seasonal and other environmental challenges by entering a state of dormancy, diapause. Thus, insects exposed to decreased temperature and short photoperiod enter a state of arrested development, lowered metabolism, and increased stress resistance. Drosophila melanogaster females can enter a shallow reproductive diapause in the adult stage, which drastically reduces organismal senescence, but little is known about the physiology and endocrinology associated with this dormancy, and the genes involved in its regulation. We induced diapause in D. melanogaster and monitored effects over 12 weeks on dynamics of ovary development, carbohydrate and lipid metabolism, as well as expression of genes involved in endocrine signaling, metabolism and innate immunity. During diapause food intake diminishes drastically, but circulating and stored carbohydrates and lipids are elevated. Gene transcripts of glucagon- and insulin-like peptides increase, and expression of several target genes of these peptides also change. Four key genes in innate immunity can be induced by infection in diapausing flies, and two of these, drosomycin and cecropin A1, are upregulated by diapause independently of infection. Diapausing flies display very low mortality, extended lifespan and decreased aging of the intestinal epithelium. Many phenotypes induced by diapause are reversed after one week of recovery from diapause conditions. Furthermore, mutant flies lacking specific insulin-like peptides (dilp5 and dilp2-3) display increased diapause incidence. Our study provides a first comprehensive characterization of reproductive diapause in D. melanogaster, and evidence that glucagon- and insulin-like signaling are among the key regulators of the altered physiology during this dormancy. PMID:25393614

  10. The town Crepis and the country Crepis: How does fragmentation affect a plant-pollinator interaction?

    NASA Astrophysics Data System (ADS)

    Andrieu, Emilie; Dornier, Antoine; Rouifed, Soraya; Schatz, Bertrand; Cheptou, Pierre-Olivier

    2009-01-01

    In fragmented habitats, one cause of the decrease of plant diversity and abundance is the disruption of plant-animal interactions, and in particular plant-pollinator interactions. Since habitat fragmentation acts both on pollinator behaviour and plant reproduction, its consequences for the stability of such interactions are complex. An extreme case of habitat fragmentation occurs in urbanised areas where suitable habitat (in the present study small patches around ornamental trees) is embedded in a highly unsuitable environment (concrete matrix). Based on simple experiments, we ask whether pollinators can adapt their foraging behaviour in response to the amount of available resources (flowers) in the fragments and their isolation, as predicted by the optimal foraging theory. To do so we analysed the effect of fragmentation on the behaviour of pollinators visiting Crepis sancta (L.) Bornm. (Asteraceae), which forms large populations in the countryside and patchy populations in urban environments. More precisely we studied pollinator visitation rates, capitulum visit durations, capitulum search durations and capitulum size choice. Pollinators chose larger capitula in both types of populations and their foraging behaviour differed between the two population types in three ways: (1) pollinator visits were lower in urban fragmented populations, perhaps due to the lower accessibility of urban patches; (2) capitulum visit durations were longer in urban fragmented populations, a possible compensation of energy lost during flights among patches; and (3) capitulum search durations where longer in urban fragmented populations, which may represent an increase in capitulum prospecting effort. We discuss the possible impacts of such differences for plant population functioning in the two types of populations.

  11. Salinity and Alkaline pH in Irrigation Water Affect Marigold Plants: II. Mineral Ion Relations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scarcity of water of good quality for landscape irrigation is of outmost importance in arid and semiarid regions due to the competition with urban population. This is forcing the use of degraded waters with high levels of salinity and high pH, which may affect plant establishment and growth. The o...

  12. Poisonous plants affecting the central nervous system of horses in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poisoning by Indigofera pascuori was recently reported in horses in the state of Roraima. It causes chronic signs of sleepiness, unsteady gait, severe ataxia, and progressive weight loss. Some animals are blind. Young horses are more affected than adults. After the end of plant consumption the anima...

  13. Reproductive hacking

    PubMed Central

    Dustin Rubinstein, C; Wolfner, Mariana F

    2014-01-01

    Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through “hacking” a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones. PMID:25483253

  14. Relative abundance of an invasive alien plant affects insect-flower interaction networks in Ireland

    NASA Astrophysics Data System (ADS)

    Stout, Jane C.; Casey, Leanne M.

    2014-02-01

    Invasive alien flowering plants may affect native plant pollinator interactions and have knock on impacts on populations of native plants and animals. The magnitude of these impacts, however, may be modified by the relative abundance of the invasive plant and the number of flowers it presents.We tested this by examining the structure of insect-flower interaction networks in six sites with increasing levels of invasion by Rhododendron ponticum in Ireland.Neither flower-visiting insect abundance, species richness nor diversity were related to R. ponticum flower abundance, but the composition of insect communities was. The total number of flowers in a site increased with the relative abundance of R. ponticum flowers but the number of co-flowering native plant species in these sites was low (<6), making interaction networks relatively small.As a result, changes in interaction network properties (connectance, interaction evenness and network level specialisation), which correlated with R. ponticum flower abundance, were a result of the small network size rather than due to changes in the resilience of networks.Overall, we conclude that the impacts of invasive alien plants on native plant-pollinator interactions are not only species specific, but site specific, according to the abundance of flowers produced by both the invasive and the native plants.

  15. Plant Volatiles Induced by Herbivore Egg Deposition Affect Insects of Different Trophic Levels

    PubMed Central

    Fatouros, Nina E.; Lucas-Barbosa, Dani; Weldegergis, Berhane T.; Pashalidou, Foteini G.; van Loon, Joop J. A.; Dicke, Marcel; Harvey, Jeffrey A.; Gols, Rieta; Huigens, Martinus E.

    2012-01-01

    Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant’s volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels. PMID:22912893

  16. Inoculation of Transgenic Resistant Potato by Phytophthora infestans Affects Host Plant Choice of a Generalist Moth.

    PubMed

    Abreha, Kibrom B; Alexandersson, Erik; Vossen, Jack H; Anderson, Peter; Andreasson, Erik

    2015-01-01

    Pathogen attack and the plant's response to this attack affect herbivore oviposition preference and larval performance. Introduction of major resistance genes against Phytophthora infestans (Rpi-genes), the cause of the devastating late blight disease, from wild Solanum species into potato changes the plant-pathogen interaction dynamics completely, but little is known about the effects on non-target organisms. Thus, we examined the effect of P. infestans itself and introduction of an Rpi-gene into the crop on host plant preference of the generalist insect herbivore, Spodoptera littoralis (Lepidoptera: Noctuidae). In two choice bioassays, S. littoralis preferred to oviposit on P. infestans-inoculated plants of both the susceptible potato (cv. Desiree) and an isogenic resistant clone (A01-22: cv. Desiree transformed with Rpi-blb1), when compared to uninoculated plants of the same genotype. Both cv. Desiree and clone A01-22 were equally preferred for oviposition by S. littoralis when uninoculated plants were used, while cv. Desiree received more eggs compared to the resistant clone when both were inoculated with the pathogen. No significant difference in larval and pupal weight was found between S. littoralis larvae reared on leaves of the susceptible potato plants inoculated or uninoculated with P. infestans. Thus, the herbivore's host plant preference in this system was not directly associated with larval performance. The results indicate that the Rpi-blb1 based resistance in itself does not influence insect behavior, but that herbivore oviposition preference is affected by a change in the plant-microbe interaction. PMID:26053171

  17. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  18. How Do Earthworms, Soil Texture and Plant Composition Affect Infiltration along an Experimental Plant Diversity Gradient in Grassland?

    PubMed Central

    Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W.; Schumacher, Jens; Hildebrandt, Anke

    2014-01-01

    Background Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. Methodology/Principal Findings We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Conclusions/Significance Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications. PMID:24918943

  19. Elevated corticosterone levels decrease reproductive output of chick-rearing Adélie penguins but do not affect chick mass at fledging

    PubMed Central

    Thierry, Anne-Mathilde; Ropert-Coudert, Yan; Raclot, Thierry

    2013-01-01

    Study of physiological mechanisms can help us to understand how animals respond to changing environmental conditions. In particular, stress hormones (i.e. glucocorticoids, such as corticosterone) are described as mediating resource allocation, allowing animals to adjust their physiology and behaviour to predictable and unpredictable changes in the environment. In this study, we investigated the effects of an experimental increase in baseline corticosterone levels on the breeding effort and the reproductive output of chick-rearing male Adélie penguins (Pygoscelis adeliae). The number of chicks per nest, their body mass, and their size were monitored throughout the study. Direct observations allowed measurement of the time spent foraging at sea and caring for the young on the nest. At the end of the treatment, blood samples were collected for isotope analysis. Although all birds raised at least one chick, reproductive output was decreased by 42% in corticosterone-treated birds compared with control birds. The increase in corticosterone levels during the guard stage did not affect the mass of surviving chicks or the brood mass at fledging. Corticosterone-treated males spent on average 21% more time at the nest than control birds. However, the duration of foraging trips was similar between both groups. In addition, the similarity of isotopic signatures suggests that both groups foraged at similar locations and ingested the same prey species. The detailed on-land behaviour of birds should be examined in further studies to clarify the possible links between corticosterone levels, brooding time, and reproductive output. Understanding the relationships between glucocorticoids, fitness, and ultimately population dynamics is fundamental to enabling conservation physiology as a discipline to be successful in helping to manage species of conservation concern. PMID:27293591

  20. We Made Your Bed, Why Won't You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs.

    PubMed

    Klop-Toker, Kaya; Valdez, Jose; Stockwell, Michelle; Fardell, Loren; Clulow, Simon; Clulow, John; Mahony, Michael

    2016-01-01

    Mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. However, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. We conducted extensive monitoring of a released population of endangered green and golden bell frogs, Litoria aurea, within a created habitat, as well as complementary surveys of a surrounding wild population. We then compared differences between the created habitat and natural ponds where extant frogs either bred or didn't breed in order to determine factors that contributed to the breeding failure within the created habitat. We evaluated differences of L. aurea abundance, abundance of other fauna, vegetation, water quality, habitat structure, invasive fish, and disease between the three pond types (created habitat, breeding ponds, non-breeding ponds). We discovered that vegetation and invertebrate diversity were low within the created habitat, potentially reducing energy and nutritional resources required for breeding. Also, a greater proportion of frogs in the created habitat were carrying the chytrid fungal pathogen, Batrachochytrium dendrobatidis, compared to the wild populations. In addition to causing the potentially fatal disease, chytridiomycosis, this pathogen has been shown to reduce reproductive functioning in male L. aurea, and subsequently may have reduced reproductive activities in the created habitat. Conspecific attraction, pond hydrology, and aquatic vegetation may also have had some influence on breeding behaviours, whilst the presence of the invasive mosquitofish, Gambusia holbrooki, and heterospecific tadpoles were unlikely to have deterred L. aurea from breeding within the created habitat. Through the use of scientific testing and monitoring, this study is able to make recommendations for future

  1. We Made Your Bed, Why Won’t You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs

    PubMed Central

    Valdez, Jose; Stockwell, Michelle; Fardell, Loren; Clulow, Simon; Clulow, John; Mahony, Michael

    2016-01-01

    Mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. However, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. We conducted extensive monitoring of a released population of endangered green and golden bell frogs, Litoria aurea, within a created habitat, as well as complementary surveys of a surrounding wild population. We then compared differences between the created habitat and natural ponds where extant frogs either bred or didn’t breed in order to determine factors that contributed to the breeding failure within the created habitat. We evaluated differences of L. aurea abundance, abundance of other fauna, vegetation, water quality, habitat structure, invasive fish, and disease between the three pond types (created habitat, breeding ponds, non-breeding ponds). We discovered that vegetation and invertebrate diversity were low within the created habitat, potentially reducing energy and nutritional resources required for breeding. Also, a greater proportion of frogs in the created habitat were carrying the chytrid fungal pathogen, Batrachochytrium dendrobatidis, compared to the wild populations. In addition to causing the potentially fatal disease, chytridiomycosis, this pathogen has been shown to reduce reproductive functioning in male L. aurea, and subsequently may have reduced reproductive activities in the created habitat. Conspecific attraction, pond hydrology, and aquatic vegetation may also have had some influence on breeding behaviours, whilst the presence of the invasive mosquitofish, Gambusia holbrooki, and heterospecific tadpoles were unlikely to have deterred L. aurea from breeding within the created habitat. Through the use of scientific testing and monitoring, this study is able to make recommendations for future

  2. Factors affecting post-flight behavior in primary reproductives of the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae).

    PubMed

    Park, Yong Ihl; Bland, John M; Raina, Ashok K

    2004-06-01

    After swarming, reproductive dealates of the Formosan subterranean termite, Coptotermes formosanus, run together in tandem. The tandem running is an age-related behavioral activity in C. formosanus. This behavior was not evoked in pre-flight alates less than 6-d-old that were artificially dealated. Female age was more important than male age for evoking tandem behavior. Females and males, older than 35 days, did not exhibit this behavior. Mating status was not important for female and male dealates to form the tandem pairs. The titers of the major tergal gland component, trilinolein, did not decline significantly and remained high, not only in virgin females, but also in mated females for a period of time after swarming. On the other hand, increasing amounts of the female-specific compound trilinolein were detected in male dealates 7, 14, and 42 days after pairing. This suggests that trilinolein in the females might be transferred to the males as a nuptial gift in C. formosanus. In addition, females have structurally different lateral setae that may constitute a morphological factor involved in the tandem behavior in this species. Covering the setae with dimethyl sulfoxide prevented the tandem behavior. PMID:15183283

  3. Factors Affecting the Reproduction, Recruitment, Habitat, and Population Dynamics of Pallid Sturgeon and Shovelnose Sturgeon in the Missouri River

    USGS Publications Warehouse

    Korschgen, Carl E., (Edited By)

    2007-01-01

    For more than a hundred years, human activities have modified the natural forces that control the Missouri River and its native fish fauna. While the ecological effects of regulation and channel engineering are understood in general, the current understanding is not sufficient to guide river restoration and management. The U.S. Geological Survey (USGS) is in the third year of a multiagency research effort to determine the ecological requirements for reproduction and survival of the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorhynchus) in the Missouri River. The multidisciplinary research strategy includes components of behavior, physiology, habitat use, habitat availability, and population modeling of all life stages. Shovelnose sturgeon are used to design the strategy because they are closely related to the pallid sturgeon and are often used as a surrogate species to develop new research tools or to examine the effects of management actions or environmental variables on sturgeon biology and habitat use. During fiscal years 2005 and 2006, the U.S. Army Corps of Engineers (USACE) provided funds to USGS for tasks associated with the Comprehensive Sturgeon Research Program (CSRP) and for tasks associated with evaluation of the Sturgeon Response to Flow Modifications (SRFM). Because work activities of CSRP and SRFM are so integrated, we are providing information on activities that have been consolidated at the task level. These task activities represent chapters in this report.

  4. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p < 0.01) higher in mine affected soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals. PMID:26079739

  5. Mammalian reproduction: an ecological perspective.

    PubMed

    Bronson, F H

    1985-02-01

    The objectives of this paper are to organize our concepts about the environmental regulation of reproduction in mammals and to delineate important gaps in our knowledge of this subject. The environmental factors of major importance for mammalian reproduction are food availability, ambient temperature, rainfall, the day/night cycle and a variety of social cues. The synthesis offered here uses as its core the bioenergetic control of reproduction. Thus, for example, annual patterns of breeding are viewed as reflecting primarily the caloric costs of the female's reproductive effort as they relate to the energetic costs and gains associated with her foraging effort. Body size of the female is an important consideration since it is correlated with both potential fat reserves and life span. Variation in nutrient availability may or may not be an important consideration. The evolutionary forces that have shaped the breeding success of males usually are fundamentally different from those acting on females and, by implication, the environmental controls governing reproduction probably also often differ either qualitatively or quantitatively in the two sexes. Mammals often live in habitats where energetic and nutrient challenges vary seasonally, even in the tropics. When seasonal breeding is required, a mammal may use a predictor such as photoperiod or a secondary plant compound to prepare metabolically for reproduction. A reasonable argument can be made, however, that opportunistic breeding, unenforced by a predictor, may be the most prevalent strategy extant among today's mammals. Social cues can have potent modulating actions. They can act either via discrete neural and endocrine pathways to alter specific processes such as ovulation, or they can induce nonspecific emotional states that secondarily affect reproduction. Many major gaps remain in our knowledge about the environmental regulation of mammalian reproduction. For one, we have a paucity of information about the

  6. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  7. Pea (Pisum sativum) Seed Production as an Assay for Reproductive Effects Due to Herbicides.

    EPA Science Inventory

    Even though herbicide drift can affect plant reproduction, current plant testing protocols emphasize effects on vegetative growth. In this study, we determined whether a short–growing season plant can indicate potential effects of herbicides on seed production. Pea (Pisum sativum...

  8. Plant sterols: factors affecting their efficacy and safety as functional food ingredients

    PubMed Central

    Berger, Alvin; Jones, Peter JH; Abumweis, Suhad S

    2004-01-01

    Plant sterols are naturally occurring molecules that humanity has evolved with. Herein, we have critically evaluated recent literature pertaining to the myriad of factors affecting efficacy and safety of plant sterols in free and esterified forms. We conclude that properly solubilized 4-desmetyl plant sterols, in ester or free form, in reasonable doses (0.8–1.0 g of equivalents per day) and in various vehicles including natural sources, and as part of a healthy diet and lifestyle, are important dietary components for lowering low density lipoprotein (LDL) cholesterol and maintaining good heart health. In addition to their cholesterol lowering properties, plant sterols possess anti-cancer, anti-inflammatory, anti-atherogenicity, and anti-oxidation activities, and should thus be of clinical importance, even for those individuals without elevated LDL cholesterol. The carotenoid lowering effect of plant sterols should be corrected by increasing intake of food that is rich in carotenoids. In pregnant and lactating women and children, further study is needed to verify the dose required to decrease blood cholesterol without affecting fat-soluble vitamins and carotenoid status. PMID:15070410

  9. Carbon storage potential by four macrophytes as affected by planting diversity in a created wetland.

    PubMed

    Means, Mary M; Ahn, Changwoo; Korol, Alicia R; Williams, Lisa D

    2016-01-01

    Wetland creation has become a commonplace method for mitigating the loss of natural wetlands. Often mitigation projects fail to restore ecosystem services of the impacted natural wetlands. One of the key ecosystem services of newly created wetlands is carbon accumulation/sequestration, but little is known about how planting diversity (PD) affects the ability of herbaceous wetland plants to store carbon in newly created wetlands. Most mitigation projects involve a planting regime, but PD, which may be critical in establishing biologically diverse and ecologically functioning wetlands, is seldom required. Using a set of 34 mesocosms (∼1 m(2) each), we investigated the effects of planting diversity on carbon storage potential of four native wetland plant species that are commonly planted in created mitigation wetlands in Virginia - Carex vulpinoidea, Eleocharis obtusa, Juncus effusus, and Mimulus ringens. The plants were grown under the four distinctive PD treatments [i.e., monoculture (PD 1) through four different species mixture (PD 4)]. Plant biomass was harvested after two growing seasons and analyzed for tissue carbon content. Competition values (CV) were calculated to understand how the PD treatment affected the competitive ability of plants relative to their biomass production and thus carbon storage potentials. Aboveground biomass ranged from 988 g/m(2) - 1515 g/m(2), being greatest in monocultures, but only when compared to the most diverse mixture (p = 0.021). However, carbon storage potential estimates per mesocosm ranged between 344 g C/m(2) in the most diverse mesocosms (PD 4) to 610 g C/m(2) in monoculture ones with no significant difference (p = 0.089). CV of E. obtusa and C. vulpinoidea showed a declining trend when grown in the most diverse mixtures but J. effusus and M. ringens displayed no difference across the PD gradient (p = 0.910). In monocultures, both M. ringens, and J. effusus appeared to store carbon as biomass more

  10. A new Late Cretaceous ginkgoalean reproductive structure Nehvizdyella gen. nov. from the Czech Republic and its whole-plant reconstruction.

    PubMed

    Kvacek, Jirí; Falcon-Lang, Howard J; Dasková, Jirina

    2005-12-01

    During the Mesozoic Era, gingkoaleans comprised a diverse and widespread group. Here we describe ginkgoalean fossils in their facies context from the Late Cretaceous (Cenomanian) Peruc-Korycany Formation of the Czech Republic and present a reconstruction of tree architecture and ecology. Newly described in this study is the ovuliferous reproductive structure, Nehvizdyella bipartita gen. et sp. nov. (Ginkgoales). This ovuliferous organ consists of a bifurcating axis, terminated by large cupule-like structures, probably homologous to the collar of the recent Ginkgo. Each cupule encloses an orthotropous ovule. In specimens with the early developmental stages preserved, the entire ovule and young seed, with the exception of the micropylar area, is embedded in the cupule. Mature seeds consist of sclerotesta and sarcotesta. Monosulcate pollen grains of Cycadopites-type are found adhering to the seeds. Although similar to Ginkgo in terms of its large size and reduced number of seeds, N. bipartita differs from the extant genus in having ovules completely enclosed in a cupule-like structure. The co-occurrence of N. bipartita with ginkgoalean leaves of Eretmophyllum obtusum (Velenovský) Kvaček, J., ginkgoalean short shoots of Pecinovicladus kvacekii Falcon-Lang, and ginkgoalean trunk wood of Ginkgoxylon gruettii Pons and Vozenin-Serra in monodominant taphocoenoses at four geographically distant localities suggests that these remains all belong to one plant. This is supported by the close morphological and anatomical similarity between the different organs. Facies analysis of plant assemblages indicates that our Cretaceous tree occupied a water-stressed coastal salt marsh environment. It therefore represents the first unequivocal halophyte among the Ginkgoales. PMID:21646114

  11. Plant-bacteria bioremediation agents affect the response of plant bioindicators independent of 2-chlorobenzoic acid degradation

    SciTech Connect

    Siciliano, S.D.; Germida, J.J.

    1995-12-31

    Plants are known to degrade toxicants in soil and are potentially useful bioremediation agents. The authors developed plant-bacteria associations (e.g., Meadow brome [Bromus riparius] and Pseudomonas aeruginosa strain R75) that degrade 2-chlorobenzoic acid (2CBA) in soil, and assessed their success using Slender wheatgrass (Agropyron trachycaulum) germination as a bioindicator of 2CBA levels. Gas chromatography was used to chemically assess 2CBA levels. Specific plant-bacteria bioremediation treatments decreased soil 2CBA levels by 17 to 52%, but bioindicator response did not correspond to chemical analysis. Contaminated and uncontaminated soil was subjected to bioremediation treatments. After 42 days, uncontaminated soil was collected and amended to various 2CBA levels. This soil and the remediated soil were analyzed by the plant bioindicator and gas chromatography. Bioremediation treatments altered germination of Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass at low 2CBA levels, but increased the toxicity of 2CBA at high 2CBA levels. For example, germination in soil subjected to the Meadow brome and R75 treatment was increased by ca. 30% at 50 mg kg{sup {minus}1} 2CBA, but decreased by ca. 50% at 150 mg kg{sup {minus}1} 2CBA. The results indicate that specific plant-bacteria bioremediation treatments affect plant bioindicator response independent of 2CBA degradation, and may confound efforts to determine the toxicity of 2CBA in soil.

  12. Conditional deletion of the relaxin receptor gene in cells of smooth muscle lineage affects lower reproductive tract in pregnant mice.

    PubMed

    Kaftanovskaya, Elena M; Huang, Zaohua; Lopez, Carolina; Conrad, Kirk; Agoulnik, Alexander I

    2015-04-01

    Relaxin hormone secreted into the circulation during pregnancy was discovered through its effects on pubic symphysis relaxation and parturition. Genetic inactivation of the relaxin gene or its cognate relaxin family peptide receptor 1 (RXFP1) in mice caused failure of parturition and mammary nipple enlargement, as well as increased collagen fiber density in the cervix and vagina. However, the relaxin effect on discrete cells and tissues has yet to be determined. Using transgenic mice with a knockin LacZ reporter in the Rxfp1 allele, we showed strong expression of this gene in vaginal and cervical stromal cells, as well as pubic ligament cells. We produced a floxed Rxfp1 allele that was used in combination with the Tagln-cre transgene to generate mice with a smooth muscle-specific gene knockout. In pregnant females, the ROSA26 reporter activated by Tagln-cre was detected in smooth muscle cells of the cervix, vagina, uterine artery, and in cells of the pubic symphysis. In late pregnant females with conditional gene ablation, the length of pubic symphysis was significantly reduced compared with wild-type or heterozygous Rxfp1(+/-) females. Denser collagen content was revealed by Masson trichrome staining in reproductive tract organs, uterine artery, and pubic symphysis. The cervical and vaginal epithelium was less developed than in heterozygous or wild-type females, although nipple size was normal and the dams were able to nurse their pups. In summary, our data indicate that relaxin/RXFP1 signaling in smooth muscle cells is important for normal collagen turnover and relaxation of the pubic symphysis during pregnancy. PMID:25715795

  13. Acetylesterase-Mediated Deacetylation of Pectin Impairs Cell Elongation, Pollen Germination, and Plant Reproduction[C][W

    PubMed Central

    Gou, Jin-Ying; Miller, Lisa M.; Hou, Guichuan; Yu, Xiao-Hong; Chen, Xiao-Ya; Liu, Chang-Jun

    2012-01-01

    Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility. PMID:22247250

  14. Dioecy, more than monoecy, affects plant spatial genetic structure: the case study of Ficus

    PubMed Central

    Nazareno, Alison G; Alzate-Marin, Ana L; Pereira, Rodrigo Augusto S

    2013-01-01

    In this analysis, we attempt to understand how monoecy and dioecy drive spatial genetic structure (SGS) in plant populations. For this purpose, plants of the genus Ficus were used as a comparative model due to their particular characteristics, including high species diversity, variation in life histories, and sexual systems. One of the main issues we assessed is whether dioecious fig tree populations are more spatially genetically structured than monoecious populations. Using the Sp statistic, which allows for quantitative comparisons among different studies, we compared the extent of SGS between monoecious and dioecious Ficus species. To broaden our conclusions we used published data on an additional 27 monoecious and dioecious plant species. Furthermore, genetic diversity analyses were performed for two monoecious Ficus species using 12 microsatellite markers in order to strengthen our conclusions about SGS. Our results show that dioecy, more than monoecy, significantly contributes to SGS in plant populations. On average, the estimate of Sp was six times higher for dioecious Ficus species than monoecious Ficus species and it was two times higher in dioecious than monoecious plant species. Considering these results, we emphasize that the long-distance pollen dispersal mechanism in monoecious Ficus species seems to be the dominant factor in determining weak spatial genetic structure, high levels of genetic diversity, and lack of inbreeding. Although Ficus constitute a model species to study SGS, a more general comparison encompassing a wider range of plants is required in order to better understand how sexual systems affect genetic structure. PMID:24223285

  15. Does a decade of elevated [CO2] affect a desert perennial plant community?

    PubMed

    Newingham, Beth A; Vanier, Cheryl H; Kelly, Lauren J; Charlet, Therese N; Smith, Stanley D

    2014-01-01

    Understanding the effects of elevated [CO2 ] on plant community structure is crucial to predicting ecosystem responses to global change. Early predictions suggested that productivity in deserts would increase via enhanced water-use efficiency under elevated [CO2], but the response of intact arid plant communities to elevated [CO2 ] is largely unknown. We measured changes in perennial plant community characteristics (cover, species richness and diversity) after 10 yr of elevated [CO2] exposure in an intact Mojave Desert community at the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility. Contrary to expectations, total cover, species richness, and diversity were not affected by elevated [CO2]. Over the course of the experiment, elevated [CO2] had no effect on changes in cover of the evergreen C3 shrub, Larrea tridentata; alleviated decreases in cover of the C4 bunchgrass, Pleuraphis rigida; and slightly reduced the cover of C3 drought-deciduous shrubs. Thus, we generally found no effect of elevated [CO2] on plant communities in this arid ecosystem. Extended drought, slow plant growth rates, and highly episodic germination and recruitment of new individuals explain the lack of strong perennial plant community shifts after a decade of elevated [CO2]. PMID:24117700

  16. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    SciTech Connect

    Whitham, T.G.; Martinsen, G.D.; Keim, P.; Floate, K.D.; Dungey, H.S. |; Potts, B.M.

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  17. Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

    PubMed Central

    Shah, M. Mostafizur Rahman; Liu, Tong-Xian

    2013-01-01

    The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems. PMID:24146985

  18. Factors Affecting the Distribution Pattern of Wild Plants with Extremely Small Populations in Hainan Island, China

    PubMed Central

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012–2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  19. Factors affecting the distribution pattern of wild plants with extremely small populations in Hainan Island, China.

    PubMed

    Chen, Yukai; Yang, Xiaobo; Yang, Qi; Li, Donghai; Long, Wenxing; Luo, Wenqi

    2014-01-01

    Understanding which factors affect the distribution pattern of extremely small populations is essential to the protection and propagation of rare and endangered plant species. In this study, we established 108 plots covering the entire Hainan Island, and measured the appearance frequency and species richness of plant species with extremely small populations, as well as the ecological environments and human disturbances during 2012-2013. We explored how the ecological environments and human activities affected the distribution pattern of these extremely small populations. Results showed that the extremely small populations underwent human disturbances and threats, and they were often found in fragmental habitats. The leading factors changing the appearance frequency of extremely small populations differed among plant species, and the direct factors making them susceptible to extinction were human disturbances. The peak richness of extremely small populations always occurred at the medium level across environmental gradients, and their species richness always decreased with increasing human disturbances. However, the appearance frequencies of three orchid species increased with the increasing human disturbances. Our study thus indicate that knowledge on how the external factors, such as the ecological environment, land use type, roads, human activity, etc., affect the distribution of the extremely small populations should be taken for the better protecting them in the future. PMID:24830683

  20. Modulation of Ethylene Responses Affects Plant Salt-Stress Responses1[OA

    PubMed Central

    Cao, Wan-Hong; Liu, Jun; He, Xin-Jian; Mu, Rui-Ling; Zhou, Hua-Lin; Chen, Shou-Yi; Zhang, Jin-Song

    2007-01-01

    Ethylene signaling plays important roles in multiple aspects of plant growth and development. Its functions in abiotic stress responses remain largely unknown. Here, we report that alteration of ethylene signaling affected plant salt-stress responses. A type II ethylene receptor homolog gene NTHK1 (Nicotiana tabacum histidine kinase 1) from tobacco (N. tabacum) conferred salt sensitivity in NTHK1-transgenic Arabidopsis (Arabidopsis thaliana) plants as judged from the phenotypic change, the relative electrolyte leakage, and the relative root growth under salt stress. Ethylene precursor 1-aminocyclopropane-1-carboxylic acid suppressed the salt-sensitive phenotype. Analysis of Arabidopsis ethylene receptor gain-of-function mutants further suggests that receptor function may lead to salt-sensitive responses. Mutation of EIN2, a central component in ethylene signaling, also results in salt sensitivity, suggesting that EIN2-mediated signaling is beneficial for plant salt tolerance. Overexpression of the NTHK1 gene or the receptor gain-of-function activated expression of salt-responsive genes AtERF4 and Cor6.6. In addition, the transgene NTHK1 mRNA was accumulated under salt stress, suggesting a posttranscriptional regulatory mechanism. These findings imply that ethylene signaling may be required for plant salt tolerance. PMID:17189334

  1. Can corn plants inoculated with arbuscular mycorrhiza fungi affect soil clay assemblage?

    NASA Astrophysics Data System (ADS)

    Adamo, P.; Cozzolino, V.; Di Meo, V.; Velde, B.

    2012-04-01

    Plants can extract K from exchangeable and non-exchangeable sites in the soil clay mineral structures. The latter, known as fixed K, is usually seen as an illite layer, i.e. an anhydrous K layer that forms a 1.0 nm structural layer unit as seen by X-ray diffraction. Nutrient availability can be enhanced in the root zone by arbuscular mycorrhiza fungi. In this study, the effects of non-inoculated and Glomus intraradices inoculated corn plant growth under different experimental conditions on soil K-bearing clay minerals were identified. The soil, a Vertic Xerofluvent, was planted in corn in a 2008-2010 randomized field experiment. Bulk and rhizosphere soil sampling was carried out from May to September 2010 from fertilized plots (N200P90K160 and N200P0K160) with and without plants. According to XRD analysis, three major K-bearing minerals were present in soil: smectite-rich mixed layer mineral, illite-rich mixed layer mineral and illite. Results at 40DAS indicate extraction of K from clay minerals by plant uptake, whereas at 130DAS much of the nutrient seems to be returned to the soil. There is an apparent difference between bulk and rhizophere clays. The XRD patterns are not unequivocally affected by Glomus inoculation. There are observable changes in clay mineralogy in fallow unfertilized compared with fertilized soil. In the studied soil, the illite rich mixed-layer minerals seem to be the source of K absorbed by plants, while illite acts as sink of K released from the plant-microorganisms system at the end of the growing season and as source for the following crop.

  2. CLIMATE CONDITIONS AFFECTING THE WITHIN-PLANT SPREAD OF BROAD MITES ON AZALEA.

    PubMed

    Mechant, E; Pauwels, E; Gobin, B

    2014-01-01

    The broad mite Polyphagotarsonemus latus (Banks) is considered a major pest in potted azalea, Flanders' flagship ornamental crop of Rhododendron simsii hybrids. In addition to severe economic damage, the broad mite is dreaded for its increasing resistance to acaricides. Due to restrictions in the use of broad spectrum acaricides, Belgian azalea growers are left with only three compounds, belonging to two mode of action groups and restricted in their number of applications, for broad mite control: abamectin, milbemectin and pyrethrin. Although P. latus can be controlled with predatory mites, the high cost of this system makes it (not yet) feasible for integration into standard azalea pest management systems. Hence, a maximum efficacy of treatments with available compounds is essential. Because abamectin, milbemectin and pyrethrin are contact acaricides with limited trans laminar flow, only broad mites located on shoot tips of azalea plants will be controlled after spraying. Consequently, the efficacy of chemical treatments is influenced by the location and spread of P. latus on the plant. Unfortunately, little is known on broad mites' within-plant spread or how it is affected by climatic conditions like temperature and relative humidity. Therefore, experiments were set up to verify whether climate conditions have an effect on the location and migration of broad mites on azalea. Broad mite infected azalea plants were placed in standard growth chambers under different temperature (T:2.5-25°C) and relative humidity (RH:55-80%) treatments. Within-plant spread was determined by counting mites on the shoot tips and inner leaves of azalea plants. Results indicate that temperature and relative humidity have no significant effect on the within-plant spread of P. latus. To formulate recommendations for optimal spray conditions to maximize the efficacy of broad mite control with acaricides, further experiments on the effect of light intensity and rain are scheduled. PMID

  3. The affective (re)production of refugee representations through educational policies and practices: Reconceptualising the role of emotion for peace education in a divided country

    NASA Astrophysics Data System (ADS)

    Zembylas, Michalinos

    2012-08-01

    Drawing into a discussion of the politicisation of emotion, this paper develops a framework to analyse some of the processes and strategies by which educational policies and pedagogical practices "emotionalise" the representation of refugees in conflict-ridden societies such as Cyprus and explores the implications for peace education. In particular, this paper aims to refine our understanding of how emotions affect the ways in which educational policies and practices reproduce self-other dichotomies through certain representations of the refugee experience. It is argued that these dichotomies are relevant to the emotional reactions against peace education initiatives. Second, this paper examines alternative possibilities of promoting peaceful coexistence, while taking into consideration the affective (re)production of refugee representations yet without undermining the refugee experience. Better understanding of how emotion is involved will help educational policymakers and teachers in divided societies to take into account the hitherto poorly developed aspects of the ways in which emotions, the refugee experience and peace education are inextricably intertwined.

  4. Peri-pubertal administration of 3-nitro-1,2,4-triazol-5-one (NTO) affects reproductive organ development in male but not female Sprague Dawley rats.

    PubMed

    Lent, Emily May; Crouse, Lee C B; Wallace, Shannon M; Carroll, Erica E

    2015-11-01

    Nitrotriazolone (3-nitro-1,2,4-triazol-5-one; NTO) is an insensitive munition that has demonstrated effects on reproductive organs in adult male rats. NTO was administered to male (0, 250, and 500milligrams per kilogram per day (mg/kg-day)) and female (0, 500, and 1000mg/kg-day) Sprague-Dawley rats (15/sex/group) via oral gavage from weaning through post-natal day 53/54 and 42/43, respectively. Age and body mass at vaginal opening (VO) and preputial separation (PPS), as well as all measures of estrous cyclicity were not affected by treatment with NTO. Males treated with NTO exhibited reductions in testis mass associated with tubular degeneration/atrophy. Less pronounced reductions in accessory sex organ masses were also observed in the 500mg/kg-day group. Treatment with NTO did not affect thyroid hormone or testosterone levels. These findings suggest that NTO is not acting as an estrogen or thyroid active compound, but may indicate effects on steroidogenesis and/or direct testicular toxicity. PMID:25962730

  5. How plant architecture affects light absorption and photosynthesis in tomato: towards an ideotype for plant architecture using a functional–structural plant model

    PubMed Central

    Sarlikioti, V.; de Visser, P. H. B.; Buck-Sorlin, G. H.; Marcelis, L. F. M.

    2011-01-01

    Background and Aims Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a range of different plant architectural characteristics was tested for two different seasons in order to find the optimal architecture with respect to light absorption and photosynthesis. Methods Simulations were performed with an FSPM of a greenhouse-grown tomato crop. Sensitivity analyses were carried out for leaf elevation angle, leaf phyllotaxis, leaflet angle, leaf shape, leaflet arrangement and internode length. From the results of this analysis two possible ideotypes were proposed. Four different vertical light distributions were also tested, while light absorption cumulated over the whole canopy was kept the same. Key Results Photosynthesis was augmented by 6 % in winter and reduced by 7 % in summer, when light absorption in the top part of the canopy was increased by 25 %, while not changing light absorption of the canopy as a whole. The measured plant structure was already optimal with respect to leaf elevation angle, leaflet angle and leaflet arrangement for both light absorption and photosynthesis while phyllotaxis had no effect. Increasing the length : width ratio of leaves by 1·5 or increasing internode length from 7 cm to 12 cm led to an increase of 6–10 % for light absorption and photosynthesis. Conclusions At high light intensities (summer) deeper penetration of light in the canopy improves crop photosynthesis, but not at low light intensities (winter). In particular, internode length and leaf shape affect the vertical distribution of light in the canopy. A new plant ideotype with more spacious canopy architecture due to long internodes and long and narrow leaves led to an increase in crop photosynthesis of up to 10 %. PMID:21865217

  6. Metals and female reproductive toxicity.

    PubMed

    Sengupta, P; Banerjee, R; Nath, S; Das, S; Banerjee, S

    2015-07-01

    Research into occupational exposure of metals and consequences of reproductive systems has made imperative scientific offerings in the preceding few decades. Early research works focused on possible effects on the reproductive functions rather than the complete reproductive health of the woman. Later, it was realized that metals, as reproductive toxins, may also induce hormonal changes affecting other facets of reproductive health such as the menstrual cycle, ovulation, and fertility. Concern is now shifting from considerations for the pregnant woman to the entire spectrum of occupational health threats and thus reproductive health among women. PMID:25425549

  7. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen.

    PubMed

    Cárcamo, Héctor A; Herle, Carolyn E; Lupwayi, Newton Z

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs. PMID:26106086

  8. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen

    PubMed Central

    Cárcamo, Héctor A.; Herle, Carolyn E.; Lupwayi, Newton Z.

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs. PMID:26106086

  9. Colorimetric Method for Identifying Plant Essential Oil Components That Affect Biofilm Formation and Structure

    PubMed Central

    Niu, C.; Gilbert, E. S.

    2004-01-01

    The specific biofilm formation (SBF) assay, a technique based on crystal violet staining, was developed to locate plant essential oils and their components that affect biofilm formation. SBF analysis determined that cinnamon, cassia, and citronella oils differentially affected growth-normalized biofilm formation by Escherichia coli. Examination of the corresponding essential oil principal components by the SBF assay revealed that cinnamaldehyde decreased biofilm formation compared to biofilms grown in Luria-Bertani broth, eugenol did not result in a change, and citronellol increased the SBF. To evaluate these results, two microscopy-based assays were employed. First, confocal laser scanning microscopy (CLSM) was used to examine E. coli biofilms cultivated in flow cells, which were quantitatively analyzed by COMSTAT, an image analysis program. The overall trend for five parameters that characterize biofilm development corroborated the findings of the SBF assay. Second, the results of an assay measuring growth-normalized adhesion by direct microscopy concurred with the results of the SBF assay and CLSM imaging. Viability staining indicated that there was reduced toxicity of the essential oil components to cells in biofilms compared to the toxicity to planktonic cells but revealed morphological damage to E. coli after cinnamaldehyde exposure. Cinnamaldehyde also inhibited the swimming motility of E. coli. SBF analysis of three Pseudomonas species exposed to cinnamaldehyde, eugenol, or citronellol revealed diverse responses. The SBF assay could be useful as an initial step for finding plant essential oils and their components that affect biofilm formation and structure. PMID:15574886

  10. Population variation affects interactions between two California salt marsh plant species more than precipitation.

    PubMed

    Noto, Akana E; Shurin, Jonathan B

    2016-02-01

    Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation. To understand how the environment (precipitation) and variation among populations affect species interactions, we conducted a common garden experiment using two common salt marsh plant species, Salicornia pacifica and Jaumea carnosa, from six salt marshes along the California coast encompassing a large precipitation gradient. Plants were grown alone or with an individual of the opposite species from the same site and exposed to one of three precipitation regimes. J. carnosa was negatively affected in the presence of S. pacifica, while S. pacifica was facilitated by J. carnosa. The strength of these interactions varied by site of origin but not by precipitation treatment. These results suggest that phenotypic variation among populations can affect interaction strength more than environment, despite a threefold difference in precipitation. Geographic intraspecific variation may therefore play an important role in determining the strength of interactions in communities. PMID:26481794

  11. Reproductive biology of an Alpic paleo-endemic in a changing climate.

    PubMed

    Guerrina, Maria; Casazza, Gabriele; Conti, Elena; Macrì, Carmelo; Minuto, Luigi

    2016-05-01

    Climate change is known to have a profound influence on plant reproduction, mainly because it affects plant/pollinator interactions, sometimes driving plants to extinction. Starting from the Neogene, the European climate was subjected to severe alterations. Nevertheless, several genera, including Berardia, survived these climatic changes. Despite the numerous studies performed about the relationship between climate change and plant reproductive biology, equivalent studies on ancient species are lacking, even though they may furnish crucial information on the strategies that allowed them to survive drastic climatic fluctuations. We investigated floral and reproductive features in Berardia subacaulis (Asteraceae), describing pollen vectors, capitulum and florets phenology, evaluating reproductive efficiency and defining the reproductive mode of the plant with bagging experiments and test of apomixis. B. subacaulis grows in habitats with low pollination services; it is self-compatible, but many typical features favouring cross-pollination are still present: florets are characterized by incomplete protandry, capitulum protogyny and high pollen-ovule ratio. The plant is not apomictic and self-fertilization is allowed within each capitulum. Similarly to other European Alpine endemics supposed to belong to the Mediterranean ancient tropical flora, the reproductive mode observed in the monospecific genus Berardia assured reproduction also under a pollinator decline. Differently from the other endemics, it took advantage of its spontaneous self-pollination and compatibility and its generalist pollination service, common both among high altitude plants and in the Asteraceae. PMID:26886434

  12. Population size and relatedness affect fitness of a self-incompatible invasive plant.

    PubMed

    Elam, Diane R; Ridley, Caroline E; Goodell, Karen; Ellstrand, Norman C

    2007-01-01

    One of the lingering paradoxes in invasion biology is how founder populations of an introduced species are able to overcome the limitations of small size and, in a "reversal of fortune," proliferate in a new habitat. The transition from colonist to invader is especially enigmatic for self-incompatible species, which must find a mate to reproduce. In small populations, the inability to find a mate can result in the Allee effect, a positive relationship between individual fitness and population size or density. Theoretically, the Allee effect should be common in founder populations of self-incompatible colonizing species and may account for the high rate of failed introductions, but little supporting evidence exists. We created a field experiment to test whether the Allee effect affects the maternal fitness of a self-incompatible invasive species, wild radish (Raphanus sativus). We created populations of varying size and relatedness. We measured maternal fitness in terms of both fruit set per flower and seed number per fruit. We found that both population size and the level of genetic relatedness among individuals influence maternal reproductive success. Our results explicitly define an ecological genetic obstacle faced by populations of an exotic species on its way to becoming invasive. Such a mechanistic understanding of the invasions of species that require a mate can and should be exploited for both controlling current outbreaks and reducing their frequency in the future. PMID:17197422

  13. Common gas phase molecules from fungi affect seed germination and plant health in Arabidopsis thaliana

    PubMed Central

    2014-01-01

    Fungal volatile organic compounds (VOCs) play important ecophysiological roles in mediating inter-kingdom signaling with arthropods but less is known about their interactions with plants. In this study, Arabidopsis thaliana was used as a model in order to test the physiological effects of 23 common vapor-phase fungal VOCs that included alcohols, aldehydes, ketones, and other chemical classes. After exposure to a shared atmosphere with the 23 individual VOCs for 72 hrs, seeds were assayed for rate of germination and seedling formation; vegetative plants were assayed for fresh weight and chlorophyll concentration. All but five of the VOCs tested (1-decene, 2-n-heptylfuran, nonanal, geosmin and -limonene) had a significant effect in inhibiting either germination, seedling formation or both. Seedling formation was entirely inhibited by exposure to 1-octen-3-one, 2-ethylhexanal, 3-methylbutanal, and butanal. As assayed by a combination of fresh weight and chlorophyll concentration, 2-ethylhexanal had a negative impact on two-week-old vegetative plants. Three other compounds (1-octen-3-ol, 2-ethylhexanal, and 2-heptylfuran) decreased fresh weight alone. Most of the VOCs tested did not change the fresh weight or chlorophyll concentration of vegetative plants. In summary, when tested as single compounds, fungal VOCs affected A. thaliana in positive, negative or neutral ways. PMID:25045602

  14. Different Degrees of Plant Invasion Significantly Affect the Richness of the Soil Fungal Community

    PubMed Central

    Si, Chuncan; Liu, Xueyan; Wang, Congyan; Wang, Lei; Dai, Zhicong; Qi, Shanshan; Du, Daolin

    2013-01-01

    Several studies have shown that soil microorganisms play a key role in the success of plant invasion. Thus, ecologists have become increasingly interested in understanding the ecological effects of biological invasion on soil microbial communities given continuing increase in the effects of invasive plants on native ecosystems. This paper aims to provide a relatively complete depiction of the characteristics of soil microbial communities under different degrees of plant invasion. Rhizospheric soils of the notorious invasive plant Wedelia trilobata with different degrees of invasion (uninvaded, low-degree, and high-degree using its coverage in the invaded ecosystems) were collected from five discrete areas in Hainan Province, P. R. China. Soil physicochemical properties and community structure of soil microorganisms were assessed. Low degrees of W. trilobata invasion significantly increased soil pH values whereas high degrees of invasion did not significantly affected soil pH values. Moreover, the degree of W. trilobata invasion exerted significant effects on soil Ca concentration but did not significantly change other indices of soil physicochemical properties. Low and high degrees of W. trilobata invasion increased the richness of the soil fungal community but did not pose obvious effects on the soil bacterial community. W. trilobata invasion also exerted obvious effects on the community structure of soil microorganisms that take part in soil nitrogen cycling. These changes in soil physicochemical properties and community structure of soil microbial communities mediated by different degrees of W. trilobata invasion may present significant functions in further facilitating the invasion process. PMID:24392015

  15. Plant species richness and functional traits affect community stability after a flood event.

    PubMed

    Fischer, Felícia M; Wright, Alexandra J; Eisenhauer, Nico; Ebeling, Anne; Roscher, Christiane; Wagg, Cameron; Weigelt, Alexandra; Weisser, Wolfgang W; Pillar, Valério D

    2016-05-19

    Climate change is expected to increase the frequency and magnitude of extreme weather events. It is therefore of major importance to identify the community attributes that confer stability in ecological communities during such events. In June 2013, a flood event affected a plant diversity experiment in Central Europe (Jena, Germany). We assessed the effects of plant species richness, functional diversity, flooding intensity and community means of functional traits on different measures of stability (resistance, resilience and raw biomass changes from pre-flood conditions). Surprisingly, plant species richness reduced community resistance in response to the flood. This was mostly because more diverse communities grew more immediately following the flood. Raw biomass increased over the previous year; this resulted in decreased absolute value measures of resistance. There was no clear response pattern for resilience. We found that functional traits drove these changes in raw biomass: communities with a high proportion of late-season, short-statured plants with dense, shallow roots and small leaves grew more following the flood. Late-growing species probably avoided the flood, whereas greater root length density might have allowed species to better access soil resources brought from the flood, thus growing more in the aftermath. We conclude that resource inputs following mild floods may favour the importance of traits related to resource acquisition and be less associated with flooding tolerance. PMID:27114578

  16. Evolution of the Plant Reproduction Master Regulators LFY and the MADS Transcription Factors: The Role of Protein Structure in the Evolutionary Development of the Flower

    PubMed Central

    Silva, Catarina S.; Puranik, Sriharsha; Round, Adam; Brennich, Martha; Jourdain, Agnès; Parcy, François; Hugouvieux, Veronique; Zubieta, Chloe

    2016-01-01

    Understanding the evolutionary leap from non-flowering (gymnosperms) to flowering (angiosperms) plants and the origin and vast diversification of the floral form has been one of the focuses of plant evolutionary developmental biology. The evolving diversity and increasing complexity of organisms is often due to relatively small changes in genes that direct development. These “developmental control genes” and the transcription factors (TFs) they encode, are at the origin of most morphological changes. TFs such as LEAFY (LFY) and the MADS-domain TFs act as central regulators in key developmental processes of plant reproduction including the floral transition in angiosperms and the specification of the male and female organs in both gymnosperms and angiosperms. In addition to advances in genome wide profiling and forward and reverse genetic screening, structural techniques are becoming important tools in unraveling TF function by providing atomic and molecular level information that was lacking in purely genetic approaches. Here, we summarize previous structural work and present additional biophysical and biochemical studies of the key master regulators of plant reproduction – LEAFY and the MADS-domain TFs SEPALLATA3 and AGAMOUS. We discuss the impact of structural biology on our understanding of the complex evolutionary process leading to the development of the bisexual flower. PMID:26779227

  17. A hyperparasite affects the population dynamics of a wild plant pathogen

    PubMed Central

    Tollenaere, C; Pernechele, B; Mäkinen, H S; Parratt, S R; Németh, M Z; Kovács, G M; Kiss, L; Tack, A J M; Laine, A-L

    2014-01-01

    Assessing the impact of natural enemies of plant and animal pathogens on their host's population dynamics is needed to determine the role of hyperparasites in affecting disease dynamics, and their potential for use in efficient control strategies of pathogens. Here, we focus on the long-term study describing metapopulation dynamics of an obligate pathogen, the powdery mildew (Podosphaera plantaginis) naturally infecting its wild host plant (Plantago lanceolata) in the fragmented landscape of the Åland archipelago (southwest Finland). Regionally, the pathogen persists through a balance of extinctions and colonizations, yet factors affecting extinction rates remain poorly understood. Mycoparasites of the genus Ampelomyces appear as good candidates for testing the role of a hyperparasite, i.e. a parasite of other parasites, in the regulation of their fungal hosts' population dynamics. For this purpose, we first designed a quantitative PCR assay for detection of Ampelomyces spp. in field-collected samples. This newly developed molecular test was then applied to a large-scale sampling within the Åland archipelago, revealing that Ampelomyces is a widespread hyperparasite in this system, with high variability in prevalence among populations. We found that the hyperparasite was more common on leaves where multiple powdery mildew strains coexist, a pattern that may be attributed to differential exposure. Moreover, the prevalence of Ampelomyces at the plant level negatively affected the overwinter survival of its fungal host. We conclude that this hyperparasite may likely impact on its host population dynamics and argue for increased focus on the role of hyperparasites in disease dynamics. PMID:25204419

  18. A hyperparasite affects the population dynamics of a wild plant pathogen.

    PubMed

    Tollenaere, C; Pernechele, B; Mäkinen, H S; Parratt, S R; Németh, M Z; Kovács, G M; Kiss, L; Tack, A J M; Laine, A-L

    2014-12-01

    Assessing the impact of natural enemies of plant and animal pathogens on their host's population dynamics is needed to determine the role of hyperparasites in affecting disease dynamics, and their potential for use in efficient control strategies of pathogens. Here, we focus on the long-term study describing metapopulation dynamics of an obligate pathogen, the powdery mildew (Podosphaera plantaginis) naturally infecting its wild host plant (Plantago lanceolata) in the fragmented landscape of the Åland archipelago (southwest Finland). Regionally, the pathogen persists through a balance of extinctions and colonizations, yet factors affecting extinction rates remain poorly understood. Mycoparasites of the genus Ampelomyces appear as good candidates for testing the role of a hyperparasite, i.e. a parasite of other parasites, in the regulation of their fungal hosts' population dynamics. For this purpose, we first designed a quantitative PCR assay for detection of Ampelomyces spp. in field-collected samples. This newly developed molecular test was then applied to a large-scale sampling within the Åland archipelago, revealing that Ampelomyces is a widespread hyperparasite in this system, with high variability in prevalence among populations. We found that the hyperparasite was more common on leaves where multiple powdery mildew strains coexist, a pattern that may be attributed to differential exposure. Moreover, the prevalence of Ampelomyces at the plant level negatively affected the overwinter survival of its fungal host. We conclude that this hyperparasite may likely impact on its host population dynamics and argue for increased focus on the role of hyperparasites in disease dynamics. PMID:25204419

  19. Spectral quality affects disease development of three pathogens on hydroponically grown plants

    NASA Technical Reports Server (NTRS)

    Schuerger, A. C.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  20. Soil biota can change after exotic plant invasion: Does this affect ecosystem processes?

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Sherrod, S.K.; Moldenke, A.

    2005-01-01

    Invasion of the exotic annual grass Bromus tectorum into stands of the native perennial grass Hilaria jamesii significantly reduced the abundance of soil biota, especially microarthropods and nematodes. Effects of invasion on active and total bacterial and fungal biomass were variable, although populations generally increased after 50+ years of invasion. The invasion of Bromus also resulted in a decrease in richness and a species shift in plants, microarthropods, fungi, and nematodes. However, despite the depauperate soil fauna at the invaded sites, no effects were seen on cellulose decomposition rates, nitrogen mineralization rates, or vascular plant growth. When Hilaria was planted into soils from not-invaded, recently invaded, and historically invaded sites (all currently or once dominated by Hilaria), germination and survivorship were not affected. In contrast, aboveground Hilaria biomass was significantly greater in recently invaded soils than in the other two soils. We attributed the Hilaria response to differences in soil nutrients present before the invasion, especially soil nitrogen, phosphorus, and potassium, as these nutrients were elevated in the soils that produced the greatest Hilaria biomass. Our data suggest that it is not soil biotic richness per se that determines soil process rates or plant productivity, but instead that either (1) the presence of a few critical soil food web taxa can keep ecosystem function high, (2) nutrient loss is very slow in this ecosystem, and/or (3) these processes are microbially driven. However, the presence of Bromus may reduce key soil nutrients over time and thus may eventually suppress native plant success. ?? 2005 by the Ecological Society of America.

  1. Bioaerosols from a Food Waste Composting Plant Affect Human Airway Epithelial Cell Remodeling Genes

    PubMed Central

    Chang, Ming-Wei; Lee, Chung-Ru; Hung, Hsueh-Fen; Teng, Kuo-Sheng; Huang, Hsin; Chuang, Chun-Yu

    2013-01-01

    The composting procedure in food waste plants generates airborne bioaerosols that have the potential to damage human airway epithelial cells. Persistent inflammation and repair responses induce airway remodeling and damage to the respiratory system. This study elucidated the expression changes of airway remodeling genes in human lung mucoepidermoid NCI-H292 cells exposed to bioaerosols from a composting plant. Different types of microorganisms were detectable in the composting plant, using the agar culture method. Real-time polymerase chain reaction was used to quantify the level of Aspergillus fumigatus and the profile of remodeling genes. The real-time PCR results indicated that the amount of A. fumigatus in the composting hall was less than 102 conidia. The endotoxins in the field bioaerosols were determined using a limulus amebocyte lysate test. The endotoxin levels depended on the type of particulate matter (PM), with coarse particles (2.5–10 μm) having higher endotoxin levels than did fine particles (0.5–2.5 μm). After exposure to the conditioned medium of field bioaerosol samples, NCI-H292 cells showed increased pro-inflammatory interleukin (IL)-6 release and activated epidermal growth factor receptor (EGFR), transforming growth factor (TGF)-β1 and cyclin-dependent kinase inhibitor 1 (p21WAF1/CIP1) gene expression, but not of matrix metallopeptidase (MMP)-9. Airborne endotoxin levels were higher inside the composting hall than they were in other areas, and they were associated with PM. This suggested that airborne bioaerosols in the composting plant contained endotoxins and microorganisms besides A. fumigatus that cause the inflammatory cytokine secretion and augment the expression of remodeling genes in NCI-H292 cells. It is thus necessary to monitor potentially hazardous materials from bioaerosols in food composting plants, which could affect the health of workers. PMID:24368426

  2. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  3. Disentangling Facilitation Along the Life Cycle: Impacts of Plant–Plant Interactions at Vegetative and Reproductive Stages in a Mediterranean Forb

    PubMed Central

    García-Cervigón, Ana I.; Iriondo, José M.; Linares, Juan C.; Olano, José M.

    2016-01-01

    Facilitation enables plants to improve their fitness in stressful environments. The overall impact of plant–plant interactions on the population dynamics of protégées is the net result of both positive and negative effects that may act simultaneously along the plant life cycle, and depends on the environmental context. This study evaluates the impact of the nurse plant Juniperus sabina on different stages of the life cycle of the forb Helleborus foetidus. Growth, number of leaves, flowers, carpels, and seeds per flower were compared for 240 individuals collected under nurse canopies and in open areas at two sites with contrasting stress levels. Spatial associations with nurse plants and age structures were also checked. A structural equation model was built to test the effect of facilitation on fecundity, accounting for sequential steps from flowering to seed production. The net impact of nurse plants depended on a combination of positive and negative effects on vegetative and reproductive variables. Although nurse plants caused a decrease in flower production at the low-stress site, their net impact there was neutral. In contrast, at the high-stress site the net outcome of plant–plant interactions was positive due to an increase in effective recruitment, plant density, number of viable carpels per flower, and fruit set under nurse canopies. The naturally lower rates of secondary growth and flower production at the high-stress site were compensated by the net positive impact of nurse plants here. Our results emphasize the need to evaluate entire processes and not only final outcomes when studying plant–plant interactions. PMID:26904086

  4. Two HAP2-GCS1 homologs responsible for gamete interactions in the cellular slime mold with multiple mating types: Implication for common mechanisms of sexual reproduction shared by plants and protozoa and for male-female differentiation.

    PubMed

    Okamoto, Marina; Yamada, Lixy; Fujisaki, Yukie; Bloomfield, Gareth; Yoshida, Kentaro; Kuwayama, Hidekazu; Sawada, Hitoshi; Mori, Toshiyuki; Urushihara, Hideko

    2016-07-01

    Fertilization is a central event in sexual reproduction, and understanding its molecular mechanisms has both basic and applicative biological importance. Recent studies have uncovered the molecules that mediate this process in a variety of organisms, making it intriguing to consider conservation and evolution of the mechanisms of sexual reproduction across phyla. The social amoeba Dictyostelium discoideum undergoes sexual maturation and forms gametes under dark and humid conditions. It exhibits three mating types, type-I, -II, and -III, for the heterothallic mating system. Based on proteome analyses of the gamete membranes, we detected expression of two homologs of the plant fertilization protein HAP2-GCS1. When their coding genes were disrupted in type-I and type-II strains, sexual potency was completely lost, whereas disruption in the type-III strain did not affect mating behavior, suggesting that the latter acts as female in complex organisms. Our results demonstrate the highly conserved function of HAP2-GCS1 in gamete interactions and suggest the presence of additional allo-recognition mechanisms in D. discoideum gametes. PMID:27189178

  5. Pathway-based approaches for assessment of real-time exposure to an estrogenic wastewater treatment plant effluent on fathead minnow reproduction

    EPA Science Inventory

    Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds, such as estrogens, that can affect hypothalamic-pituitary-gonadal axis function in exposed organisms. The presen...

  6. Impact of the environment on reproductive health.

    PubMed

    1991-01-01

    damage is reported for fetuses and infants exposed to methyl mercury. There is the beginning of evidence that complications of pregnancy may be related to pollution levels surrounding industrial plants. Reproductive health is affected through chromosome damage and cell destruction, prenatal death, altered growth, fetal abnormalities, postnatal death, functional learning deficits, and premature aging. PMID:12285819

  7. Burkholderia cenocepacia Lipopolysaccharide Modification and Flagellin Glycosylation Affect Virulence but Not Innate Immune Recognition in Plants

    PubMed Central

    Khodai-Kalaki, Maryam; Andrade, Angel; Fathy Mohamed, Yasmine

    2015-01-01

    ABSTRACT Burkholderia cenocepacia causes opportunistic infections in plants, insects, animals, and humans, suggesting that “virulence” depends on the host and its innate susceptibility to infection. We hypothesized that modifications in key bacterial molecules recognized by the innate immune system modulate host responses to B. cenocepacia. Indeed, modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose and flagellin glycosylation attenuates B. cenocepacia infection in Arabidopsis thaliana and Galleria mellonella insect larvae. However, B. cenocepacia LPS and flagellin triggered rapid bursts of nitric oxide and reactive oxygen species in A. thaliana leading to activation of the PR-1 defense gene. These responses were drastically reduced in plants with fls2 (flagellin FLS2 host receptor kinase), Atnoa1 (nitric oxide-associated protein 1), and dnd1-1 (reduced production of nitric oxide) null mutations. Together, our results indicate that LPS modification and flagellin glycosylation do not affect recognition by plant receptors but are required for bacteria to establish overt infection. PMID:26045541

  8. Host plant affects the sexual attractiveness of the female white-spotted longicorn beetle, Anoplophora malasiaca.

    PubMed

    Yasui, Hiroe; Fujiwara-Tsujii, Nao

    2016-01-01

    Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female's sexual attractiveness. PMID:27412452

  9. Host plant affects the sexual attractiveness of the female white-spotted longicorn beetle, Anoplophora malasiaca

    PubMed Central

    Yasui, Hiroe; Fujiwara-Tsujii, Nao

    2016-01-01

    Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female’s sexual attractiveness. PMID:27412452

  10. Does Plant Biomass Manipulation in Static Chambers Affect Nitrous Oxide Emissions from Soils?

    PubMed

    Collier, Sarah M; Dean, Andrew P; Oates, Lawrence G; Ruark, Matthew D; Jackson, Randall D

    2016-03-01

    One of the most widespread approaches for measurement of greenhouse gas emissions from soils involves the use of static chambers. This method is relatively inexpensive, is easily replicated, and is ideally suited to plot-based experimental systems. Among its limitations is the loss of detection sensitivity with increasing chamber height, which creates challenges for deployment in systems including tall vegetation. It is not always possible to avoid inclusion of plants within chambers or to extend chamber height to fully accommodate plant growth. Thus, in many systems, such as perennial forages and biomass crops, plants growing within static chambers must either be trimmed or folded during lid closure. Currently, data on how different types of biomass manipulation affect measured results is limited. Here, we compare the effects of cutting vs. folding of biomass on nitrous oxide measurements in switchgrass ( L.) and alfalfa ( L.) systems. We report only limited evidence of treatment effects during discrete sampling events and little basis for concern that effects may intensify over time as biomass manipulation is repeatedly imposed. However, nonsignificant treatment effects that were consistently present amounted to significant overall trends in three out of the four systems studied. Such minor disparities in flux could amount to considerable quantities over time, suggesting that caution should be exercised when comparing cumulative emission values from studies using different biomass manipulation strategies. PMID:27065424

  11. Growth, reproductive phenology and yield responses of a potential biofuel plant, Jatropha curcas grown under projected 2050 levels of elevated CO2.

    PubMed

    Kumar, Sumit; Chaitanya, Bharatula S K; Ghatty, Sreenivas; Reddy, Attipalli R

    2014-11-01

    Jatropha (Jatropha curcas) is a non-edible oil producing plant which is being advocated as an alternative biofuel energy resource. Its ability to grow in diverse soil conditions and minimal requirements of essential agronomical inputs compared with other oilseed crops makes it viable for cost-effective advanced biofuel production. We designed a study to investigate the effects of elevated carbon dioxide concentration ([CO(2)]) (550 ppm) on the growth, reproductive development, source-sink relationships, fruit and seed yield of J. curcas. We report, for the first time that elevated CO(2) significantly influences reproductive characteristics of Jatropha and improve its fruit and seed yields. Net photosynthetic rate of Jatropha was 50% higher in plants grown in elevated CO(2) compared with field and ambient CO(2) -grown plants. The study also revealed that elevated CO(2) atmosphere significantly increased female to male flower ratio, above ground biomass and carbon sequestration potential in Jatropha (24 kg carbon per tree) after 1 year. Our data demonstrate that J. curcas was able to sustain enhanced rate of photosynthesis in elevated CO(2) conditions as it had sufficient sink strength to balance the increased biomass yields. Our study also elucidates that the economically important traits including fruit and seed yield in elevated CO(2) conditions were significantly high in J. curcas that holds great promise as a potential biofuel tree species for the future high CO(2) world. PMID:24655305

  12. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

    PubMed Central

    Zhou, Lin; Xu, Hui; Mischke, Sue; Meinhardt, Lyndel W; Zhang, Dapeng; Zhu, Xujun; Li, Xinghui; Fang, Wanping

    2014-01-01

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant under drought stress is essential to develop drought-tolerant tea genotypes, along with crop management practices that can mitigate drought stress. The objective of the present investigation is evaluation of effects of exogenous ABA on the leaf proteome in tea plant exposed to drought stress. Leaf protein patterns of tea plants under simulated drought stress [(polyethylene glycol (PEG)-treated] and exogenous ABA treatment were analyzed in a time-course experiment using two-dimensional electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Among the 72 protein spots identified by MALDI-TOF MS, 16 proteins were downregulated and two were upregulated by exogenous ABA. The upregulated proteins have roles in glycolysis and photosystem II stabilization. Twenty-one protein spots were responsive to drought stress and most participate in carbohydrate and nitrogen metabolism, control of reactive oxygen species (ROS), defense, signaling or nucleic acid metabolism. The combined treatments of exogenous ABA and drought showed upregulation of 10 protein spots at 12 h and upregulation of 11 proteins at 72 h after initiation of drought stress. The results support the importance of the role that ABA plays in the tea plant during drought stress, by improving protein transport, carbon metabolism and expression of resistance proteins. PMID:27076915

  13. Plant material as bioaccumulator of arsenic in soils affected by mining activities

    NASA Astrophysics Data System (ADS)

    Martínez-López, Salvadora; Martínez-Sánchez, Maria Jose; García-Lorenzo, Maria Luz; Pérez-Sirvent, Carmen

    2010-05-01

    fraction (oxidaizable medium extraction procedure). Arsenic concentration in leaves was positively correlated with the arsenic extracted by HCl, with the oxidizable-organic matter and sulfides fraction and with the arsenic extracted by Mehra-Jackson extraction. According to our results, As is accumulated in the leaves of the plants and is linked with iron oxides of these soils affected by mining activities.

  14. Cadmium, copper, and lead accumulation and bioconcentration in the vegetative and reproductive organs of Raphanus sativus: implications for plant performance and pollination.

    PubMed

    Hladun, Kristen R; Parker, David R; Trumble, John T

    2015-04-01

    Several studies have found high levels of cadmium (Cd), copper (Cu), and lead (Pb) in honey bee hives located near urbanized or industrial areas. Insect herbivores and pollinators may come in contact with environmental contaminants in the leaves and flowers they forage upon in these areas. Our study quantified which of these metals are accumulated in the tissues of a common weedy plant that can serve as a route of exposure for insects. We grew Raphanus sativus (crop radish) in semi-hydroponic sand culture in the greenhouse. Plants were irrigated with nutrient solutions containing Cd, Cu, or Pb at four concentrations (control, low, medium, high). Plant performance, floral traits, and metal accumulation were measured in various vegetative and reproductive plant organs. Floral traits and flower number were unaffected by all metal treatments. Copper accumulated at the highest concentrations in flowers compared to the other two metals. Copper and Cd had the highest translocation indices, as well as higher bioconcentration factors compared to Pb, which was mostly immobile in the plant. Copper posed the highest risk due to its high mobility within the plant. In particular, accumulation of metals in leaves and flowers suggests that herbivores and pollinators visiting and foraging on these tissues may be exposed to these potentially toxic compounds. PMID:25845355

  15. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae).

    PubMed

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats. PMID

  16. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae)

    PubMed Central

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats. PMID

  17. Does vegetation complexity affect host plant chemistry, and thus multitrophic interactions, in a human-altered landscape?

    PubMed

    Wäschke, Nicole; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2015-09-01

    Anthropogenic land use may shape vegetation composition and affect trophic interactions by altering concentrations of host plant metabolites. Here, we investigated the hypotheses that: (1) plant N and defensive secondary metabolite contents of the herb Plantago lanceolata are affected by land use intensity (LUI) and the surrounding vegetation composition (=plant species richness and P. lanceolata density), and that (2) changes in plant chemistry affect abundances of the herbivorous weevils Mecinus pascuorum and Mecinus labilis, as well as their larval parasitoid Mesopolobus incultus, in the field. We determined plant species richness, P. lanceolata density, and abundances of the herbivores and the parasitoid in 77 grassland plots differing in LUI index in three regions across Germany. We also measured the N and secondary metabolite [the iridoid glycosides (IGs) aucubin and catalpol] contents of P. lanceolata leaves. Mixed-model analysis revealed that: (1) concentrations of leaf IGs were positively correlated with plant species richness; leaf N content was positively correlated with the LUI index. Furthermore: (2) herbivore abundance was not related to IG concentrations, but correlated negatively with leaf N content. Parasitoid abundance correlated positively only with host abundance over the three regions. Structural equation models revealed a positive impact of IG concentrations on parasitoid abundance in one region. We conclude that changes in plant chemistry due to land use and/or vegetation composition may affect higher trophic levels and that the manifestation of these effects may depend on local biotic or abiotic features of the landscape. PMID:25986560

  18. Unpreferred plants affect patch choice and spatial distribution of European brown hares

    NASA Astrophysics Data System (ADS)

    Kuijper, D. P. J.; Bakker, J. P.

    2008-11-01

    Many herbivore species prefer to forage on patches of intermediate biomass. Plant quality and forage efficiency are predicted to decrease with increasing plant standing crop which explains the lower preference of the herbivore. However, often is ignored that on the long-term, plant species composition is predicted to change with increasing plant standing crop. The amount of low-quality, unpreferred food plants increases with increasing plant standing crop. In the present study the effects of unpreferred plants on patch choice and distribution of European brown hare in a salt-marsh system were studied. In one experiment, unpreferred plants were removed from plots. In the second experiment, plots were planted with different densities of an unpreferred artificial plant. Removal of unpreferred plants increased hare-grazing pressure more than fivefold compared to unmanipulated plots. Planting of unpreferred plants reduced hare-grazing pressure, with a significant reduction of grazing already occurring at low unpreferred plant density. Spatial distribution of hares within this salt-marsh system was related to spatial arrangement of unpreferred plants. Hare-grazing intensity decreased strongly with increasing abundance of unpreferred plants despite a high abundance of principal food plants. The results of this study indicate that plant species replacement is an important factor determining patch choice and spatial distribution of hares next to changing plant quality. Increasing abundance of unpreferred plant species can strengthen the decreasing patch quality with increasing standing crop and can decrease grazing intensity when preferred food plants are still abundantly present.

  19. Decreased summer drought affects plant productivity and soil carbon dynamics in Mediterranean woodland

    NASA Astrophysics Data System (ADS)

    Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanović, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

    2011-06-01

    Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. The throughfall manipulation experiment started in 2004 and we report data up to the 2009 growing season. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 50 % and 220 %, respectively, as compared to control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction of precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodland. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long term soil C stocks.

  20. Decreased summer drought affects plant productivity and soil carbon dynamics in a Mediterranean woodland

    NASA Astrophysics Data System (ADS)

    Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanović, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

    2011-09-01

    Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 58 % and 220 %, respectively, as compared to the control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction in precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodlands. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long-term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long-term soil C stocks.

  1. Ozone Differentially Affects Perception of Plant Volatiles in Western Honey Bees.

    PubMed

    Dötterl, Stefan; Vater, Marina; Rupp, Thomas; Held, Andreas

    2016-06-01

    Floral scents play a key role in mediating plant-pollinator interactions. Volatile organic compounds (VOCs) emitted by flowers are used by flower visitors as olfactory cues to locate flowers, both from a distance and at close range. More recently it has been demonstrated that reactive molecules such as ozone can modify or degrade VOCs, and this may impair the communication between plants and their pollinators. However, it is not known whether such reactive molecules also may affect the olfactory system of pollinators, and thus not only influence signal transmission but perception of the signal. In this study, we used electroantennographic measurements to determine the effect of increased levels of ozone on antennal responses in western honey bees (Apis mellifera L.). Linalool and 2-phenylethanol, both known to be involved in location of flowers by the bees, and (Z)-3-hexenyl acetate, a widespread green leaf volatile also detected by bees, were used. The results showed that ozone affected antennal responses to the different substances differently. Ozone decreased antennal responses to (Z)-3-hexenyl acetate, whereas responses to linalool and 2-phenylethanol were not influenced by ozone. Overall, the study does not provide evidence that pollination by honey bees is impaired by damage in the olfactory system of the bees caused by increased levels of ozone, at least when linalool and 2-phenylethanol are the attractive signals. However, the results also suggest that ozone can change the overall perception of an odor blend. This might have negative effects in pollination systems and other organismic interactions mediated by specific ratios of compounds. PMID:27344162

  2. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    PubMed

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  3. Does nitrate co-pollution affect biological responses of an aquatic plant to two common herbicides?

    PubMed

    Nuttens, A; Chatellier, S; Devin, S; Guignard, C; Lenouvel, A; Gross, E M

    2016-08-01

    Aquatic systems in agricultural landscapes are subjected to multiple stressors, among them pesticide and nitrate run-off, but effects of both together have rarely been studied. We investigated possible stress-specific and interaction effects using the new OECD test organism, Myriophyllum spicatum, a widespread aquatic plant. In a fully factorial design, we used two widely applied herbicides, isoproturon and mesosulfuron-methyl, in concentration-response curves at two nitrate levels (219.63 and 878.52mg N-NO3). We applied different endpoints reflecting plant performance such as growth, pigment content, content in phenolic compounds, and plant stoichiometry. Relative growth rates based on length (RGR-L) were affected strongly by both herbicides, while effects on relative growth rate based on dry weight (RGR-DW) were apparent for isoproturon but hardly visible for mesosulfuron-methyl due to an increase in dry matter content. The higher nitrate level further reduced growth rates, specifically with mesosulfuron-methyl. Effects were visible between 50 and 500μgL(-1) for isoproturon and 0.5-5μgL(-1) for mesosulfuron-methyl, with some differences between endpoints. The two herbicides had opposite effects on chlorophyll, carotenoid and nitrogen contents in plants, with values increasing with increasing concentrations of isoproturon and decreasing for mesosulfuron-methyl. Herbicides and nitrate level exhibited distinct effects on the content in phenolic compounds, with higher nitrate levels reducing total phenolic compounds in controls and with isoproturon, but not with mesosulfuron-methyl. Increasing concentrations of mesosulfuron-methyl lead to a decline of total phenolic compounds, while isoproturon had little effect. Contents of carbon, nitrogen and phosphorus changed depending on the stressor combination. We observed higher phosphorus levels in plants exposed to certain concentrations of herbicides, potentially indicating a metabolic response. The C:N molar ratio

  4. Growth performance and reproductive traits at first parity of New Zealand white female rabbits as affected by heat stress and its alleviation under Egyptian conditions.

    PubMed

    Marai, I F; Ayyat, M S; Abd el-Monem, U M

    2001-12-01

    Exposing growing and adult New Zealand White (NZW) female rabbits to severe heat stress (temperature-humidity index = 28.9) during summer adversely affected their growth and reproductive traits. The traits that declined significantly (p < 0.01) were the live body weight, daily weight gain and feed intake of growing rabbits, and the litter size and litter weight at weaning (p < 0.05) and the pre-weaning weight gain of pups (p < 0.01) for adult females. The conception rate declined considerably with heat stress. The declines in the values of the digestibility coefficients due to heat stress were 7.9% (p < 0.05) for dry matter (DM), 8.1% (p < 0.05) for crude protein (CP) and 1.0% for crude fibre (CF). The traits that increased significantly (p < 0.01) due to heat stress were water intake, water/feed ratio and rectal temperature in growing rabbits and pre-weaning mortality for adult females. Alleviation of heat stress in the growing and adult female NZW rabbits was more efficient with drinking cool water (10-15 degrees C; between 10:00 and 17:00) than with supplementation with palm oil (as a source of energy) or natural clay (as a natural enhancer to growth and milk production). Supplying the animals with cool drinking water gave the highest body weight and weight gain, conception rate, litter size and weight and digestibility coefficients for DM and CP and the lowest rectal temperature, respiration rate and pre-weaning mortality. The loss in rabbit production pertaining to heat stress estimated from the percentages of decline in conception rate x pre-weaning mortality x litter weight at weaning was 73.0%. The provision of cool water restored 11/12 of heat loss. PMID:11770200

  5. An evaluation of fish early life stage tests for predicting reproductive and longer-term toxicity from plant protection product active substances.

    PubMed

    Wheeler, James R; Maynard, Samuel K; Crane, Mark

    2014-08-01

    The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reproductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for plant protection product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reproductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reproduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most plant protection

  6. Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host.

    PubMed

    Corral-Ramos, Cristina; Roncero, M Isabel G

    2015-04-01

    The role of glycogen metabolism was investigated in the fungal pathogen Fusarium oxysporum. Targeted inactivation was performed of genes responsible for glycogen biosynthesis: gnn1 encoding glycogenin, gls1 encoding glycogen synthase, and gbe1 encoding glycogen branching enzyme. Moreover genes involved in glycogen catabolism were deleted: gph1 encoding glycogen phosphorylase and gdb1 encoding glycogen de-branching enzyme. Glycogen reserves increased steadily during growth of the wild type strain in axenic cultures, to reach up to 1500μg glucose equivalents mg(-1) protein after 14 days. Glycogen accumulation was abolished in mutants lacking biosynthesis genes, whereas it increased by 20-40% or 80%, respectively, in the single and double mutants affected in catabolic genes. Transcript levels of glycogen metabolism genes during tomato plant infection peaked at four days post inoculation, similar to the results observed during axenic culture. Significant differences were observed between gdb mutants and the wild type strain for vegetative hyphal fusion ability. The single mutants defective in glycogen metabolism showed similar levels of virulence in the invertebrate animal model Galleria mellonella. Interestingly, the deletion of gdb1 reduced virulence on the plant host up to 40% compared to the wild type in single and in double mutant backgrounds, whereas the other mutants showed the virulence at the wild-type level. PMID:25865793

  7. Light Influences How the Fungal Toxin Deoxynivalenol Affects Plant Cell Death and Defense Responses

    PubMed Central

    Ansari, Khairul I.; Doyle, Siamsa M.; Kacprzyk, Joanna; Khan, Mojibur R.; Walter, Stephanie; Brennan, Josephine M.; Arunachalam, Chanemouga Soundharam; McCabe, Paul F.; Doohan, Fiona M.

    2014-01-01

    The Fusarium mycotoxin deoxynivalenol (DON) can cause cell death in wheat (Triticum aestivum), but can also reduce the level of cell death caused by heat shock in Arabidopsis (Arabidopsis thaliana) cell cultures. We show that 10 μg mL−1 DON does not cause cell death in Arabidopsis cell cultures, and its ability to retard heat-induced cell death is light dependent. Under dark conditions, it actually promoted heat-induced cell death. Wheat cultivars differ in their ability to resist this toxin, and we investigated if the ability of wheat to mount defense responses was light dependent. We found no evidence that light affected the transcription of defense genes in DON-treated roots of seedlings of two wheat cultivars, namely cultivar CM82036 that is resistant to DON-induced bleaching of spikelet tissue and cultivar Remus that is not. However, DON treatment of roots led to genotype-dependent and light-enhanced defense transcript accumulation in coleoptiles. Wheat transcripts encoding a phenylalanine ammonia lyase (PAL) gene (previously associated with Fusarium resistance), non-expressor of pathogenesis-related genes-1 (NPR1) and a class III plant peroxidase (POX) were DON-upregulated in coleoptiles of wheat cultivar CM82036 but not of cultivar Remus, and DON-upregulation of these transcripts in cultivar CM82036 was light enhanced. Light and genotype-dependent differences in the DON/DON derivative content of coleoptiles were also observed. These results, coupled with previous findings regarding the effect of DON on plants, show that light either directly or indirectly influences the plant defense responses to DON. PMID:24561479

  8. Light influences how the fungal toxin deoxynivalenol affects plant cell death and defense responses.

    PubMed

    Ansari, Khairul I; Doyle, Siamsa M; Kacprzyk, Joanna; Khan, Mojibur R; Walter, Stephanie; Brennan, Josephine M; Arunachalam, Chanemouga Soundharam; McCabe, Paul F; Doohan, Fiona M

    2014-02-01

    The Fusarium mycotoxin deoxynivalenol (DON) can cause cell death in wheat (Triticum aestivum), but can also reduce the level of cell death caused by heat shock in Arabidopsis (Arabidopsis thaliana) cell cultures. We show that 10 μg mL(-1) DON does not cause cell death in Arabidopsis cell cultures, and its ability to retard heat-induced cell death is light dependent. Under dark conditions, it actually promoted heat-induced cell death. Wheat cultivars differ in their ability to resist this toxin, and we investigated if the ability of wheat to mount defense responses was light dependent. We found no evidence that light affected the transcription of defense genes in DON-treated roots of seedlings of two wheat cultivars, namely cultivar CM82036 that is resistant to DON-induced bleaching of spikelet tissue and cultivar Remus that is not. However, DON treatment of roots led to genotype-dependent and light-enhanced defense transcript accumulation in coleoptiles. Wheat transcripts encoding a phenylalanine ammonia lyase (PAL) gene (previously associated with Fusarium resistance), non-expressor of pathogenesis-related genes-1 (NPR1) and a class III plant peroxidase (POX) were DON-upregulated in coleoptiles of wheat cultivar CM82036 but not of cultivar Remus, and DON-upregulation of these transcripts in cultivar CM82036 was light enhanced. Light and genotype-dependent differences in the DON/DON derivative content of coleoptiles were also observed. These results, coupled with previous findings regarding the effect of DON on plants, show that light either directly or indirectly influences the plant defense responses to DON. PMID:24561479

  9. Incubation Patterns in a Central-Place Forager Affect Lifetime Reproductive Success: Scaling of Patterns from a Foraging Bout to a Lifetime

    PubMed Central

    Shoji, Akiko; Elliott, Kyle H.; Aris-Brosou, Stéphane; Crump, Doug; Gaston, Anthony J.

    2011-01-01

    Background Long-lived seabirds face a conflict between current and lifelong reproductive success. During incubation shifts, egg neglect is sometimes necessary to avoid starvation, but may compromise the current reproductive attempt. However, factors underlying this decision process are poorly understood. We focus on the ancient murrelet, Synthliboramphus antiquus, an alcid with exceptionally long incubation shift lengths, and test the impact of environmental factors on incubation shift length in relation to reproductive success. Methodology/Principal Findings Using an information theoretic approach, we show that incubation shift length was a strong predictor of reproductive success for ancient murrelets at Reef Island, Haida Gwaii, British Columbia, Canada during the 2007 and 2008 breeding seasons. The most important factors explaining an individual's shift length were egg size, wind speed and the length of the mate's previous shift. Wind speed and tide height were the two most important factors for determining foraging behavior, as measured by dive frequency and depth. Conclusions/Significance Our study demonstrates that (i) species-specific reproductive strategies interact with environmental conditions such as wind speed to form multiple incubation patterns and (ii) maintaining regular incubation shifts is an essential component of reproductive success. PMID:21423631

  10. Eating disorders and reproduction.

    PubMed

    Morgan, J F

    1999-05-01

    Eating disorders are common and characteristically affect young women at what would otherwise be their peak of reproductive functioning. Anorexia nervosa and bulimia nervosa impinge on reproduction both behaviourally and physiologically, with effects on menstruation, ovarian function, fertility, sexuality and pregnancy. This review presents a summary of current knowledge and makes suggestions for future research, along with some clinical recommendations for the management of eating disorders in pregnancy. PMID:10755771

  11. The pleiotropic ABNORMAL FLOWER AND DWARF1 affects plant height, floral development and grain yield in rice.

    PubMed

    Ren, Deyong; Rao, Yuchun; Wu, Liwen; Xu, Qiankun; Li, Zizhuang; Yu, Haiping; Zhang, Yu; Leng, Yujia; Hu, Jiang; Zhu, Li; Gao, Zhenyu; Dong, Guojun; Zhang, Guangheng; Guo, Longbiao; Zeng, Dali; Qian, Qian

    2016-06-01

    Moderate plant height and successful establishment of reproductive organs play pivotal roles in rice grain production. The molecular mechanism that controls the two aspects remains unclear in rice. In the present study, we characterized a rice gene, ABNORMAL FLOWER AND DWARF1 (AFD1) that determined plant height, floral development and grain yield. The afd1 mutant showed variable defects including the dwarfism, long panicle, low seed setting and reduced grain yield. In addition, abnormal floral organs were also observed in the afd1 mutant including slender and thick hulls, and hull-like lodicules. AFD1 encoded a DUF640 domain protein and was expressed in all tested tissues and organs. Subcellular localization showed AFD1-green fluorescent fusion protein (GFP) was localized in the nucleus. Meantime, our results suggested that AFD1 regulated the expression of cell division and expansion related genes. PMID:26486996

  12. The influence of distinct pollinators on female and male reproductive success in the Rocky Mountain columbine.

    PubMed

    Brunet, Johanne; Holmquist, Karsten G A

    2009-09-01

    Although there are many reasons to expect distinct pollinator types to differentially affect a plant's reproductive success, few studies have directly examined this question. Here, we contrast the impact of two kinds of pollinators on reproductive success via male and female functions in the Rocky Mountain columbine, Aquilegia coerulea. We set up pollinator exclusion treatments in each of three patches where Aquilegia plants were visited by either day pollinators (majority bumble bees), by evening pollinators (hawkmoths), or by both (control). Day pollinators collected pollen and groomed, whereas evening pollinators collected nectar but did not groom. Maternal parents, potential fathers and progeny arrays were genotyped at five microsatellite loci. We estimated female outcrossing rate and counted seeds to measure female reproductive success and used paternity analysis to determine male reproductive success. Our results document that bumble bees frequently moved pollen among patches of plants and that, unlike hawkmoths, pollen moved by bumble bees sired more outcrossed seeds when it remained within a patch as opposed to moving between patches. Pollinator type differentially affected the outcrossing rate but not seed set, the number of outcrossed seeds or overall male reproductive success. Multiple visits to a plant and more frequent visits by bumble bees could help to explain the lack of impact of pollinator type on overall reproductive success. The increase in selfing rate with hawkmoths likely resulted from the abundant pollen available in experimental flowers. Our findings highlighted a new type of pollinator interactions that can benefit a plant species. PMID:19674307

  13. Plant-derived decapeptide OSIP108 interferes with Candida albicans biofilm formation without affecting cell viability.

    PubMed

    Delattin, Nicolas; De Brucker, Katrijn; Craik, David J; Cheneval, Olivier; Fröhlich, Mirjam; Veber, Matija; Girandon, Lenart; Davis, Talya R; Weeks, Anne E; Kumamoto, Carol A; Cos, Paul; Coenye, Tom; De Coninck, Barbara; Cammue, Bruno P A; Thevissen, Karin

    2014-05-01

    We previously identified a decapeptide from the model plant Arabidopsis thaliana, OSIP108, which is induced upon fungal pathogen infection. In this study, we demonstrated that OSIP108 interferes with biofilm formation of the fungal pathogen Candida albicans without affecting the viability or growth of C. albicans cells. OSIP108 displayed no cytotoxicity against various human cell lines. Furthermore, OSIP108 enhanced the activity of the antifungal agents amphotericin B and caspofungin in vitro and in vivo in a Caenorhabditis elegans-C. albicans biofilm infection model. These data point to the potential use of OSIP108 in combination therapy with conventional antifungal agents. In a first attempt to unravel its mode of action, we screened a library of 137 homozygous C. albicans mutants, affected in genes encoding cell wall proteins or transcription factors important for biofilm formation, for altered OSIP108 sensitivity. We identified 9 OSIP108-tolerant C. albicans mutants that were defective in either components important for cell wall integrity or the yeast-to-hypha transition. In line with these findings, we demonstrated that OSIP108 activates the C. albicans cell wall integrity pathway and that its antibiofilm activity can be blocked by compounds inhibiting the yeast-to-hypha transition. Furthermore, we found that OSIP108 is predominantly localized at the C. albicans cell surface. These data point to interference of OSIP108 with cell wall-related processes of C. albicans, resulting in impaired biofilm formation. PMID:24566179

  14. Alkaloid Quantities in Endophyte-Infected Tall Fescue are Affected by the Plant-Fungus Combination and Environment.

    PubMed

    Helander, M; Phillips, T; Faeth, S H; Bush, L P; McCulley, R; Saloniemi, I; Saikkonen, K

    2016-02-01

    Many grass species are symbiotic with systemic, vertically-transmitted, asymptomatic Epichloë endophytic fungi. These fungi often produce alkaloids that defend the host against herbivores. We studied how environmental variables affect alkaloids in endophyte-infected tall fescue (Schedonorus phoenix) from three Northern European wild origins and the widely planted US cultivar 'Kentucky-31' (KY31). The plants were grown in identical common garden experiments in Finland and Kentucky for two growing seasons. Plants were left as controls (C) or given water (W), nutrient (N) or water and nutrient (WN) treatments. For 8-10 replications of each plant origin and treatment combination in both experiments, we analyzed ergot alkaloids, lysergic acid, and lolines. In Finland, tall fescue plants produced 50 % more ergot alkaloids compared to plants of the same origin and treatments in Kentucky. Origin of the plants affected the ergot alkaloid concentration at both study sites: the wild origin plants produced 2-4 times more ergot alkaloids than KY31, but the ergot alkaloid concentration of KY31 plants was the same at both locations. Overall lysergic acid content was 60 % higher in plants grown in Kentucky than in those grown in Finland. Nutrient treatments (N, WN) significantly increased ergot alkaloid concentrations in plants from Finland but not in plants from Kentucky. These results suggest that the success of KY31 in US is not due to selection for high ergot alkaloid production but rather other traits associated with the endophyte. In addition, the environmental effects causing variation in alkaloid production of grass-endophyte combinations should be taken into account when using endophyte-infected grasses agriculturally. PMID:26815170

  15. Rhizosphere microbial community composition affects cadmium and zinc uptake by the metal-hyperaccumulating plant Arabidopsis halleri.

    PubMed

    Muehe, E Marie; Weigold, Pascal; Adaktylou, Irini J; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas; Behrens, Sebastian

    2015-03-01

    The remediation of metal-contaminated soils by phytoextraction depends on plant growth and plant metal accessibility. Soil microorganisms can affect the accumulation of metals by plants either by directly or indirectly stimulating plant growth and activity or by (im)mobilizing and/or complexing metals. Understanding the intricate interplay of metal-accumulating plants with their rhizosphere microbiome is an important step toward the application and optimization of phytoremediation. We compared the effects of a "native" and a strongly disturbed (gamma-irradiated) soil microbial communities on cadmium and zinc accumulation by the plant Arabidopsis halleri in soil microcosm experiments. A. halleri accumulated 100% more cadmium and 15% more zinc when grown on the untreated than on the gamma-irradiated soil. Gamma irradiation affected neither plant growth nor the 1 M HCl-extractable metal content of the soil. However, it strongly altered the soil microbial community composition and overall cell numbers. Pyrosequencing of 16S rRNA gene amplicons of DNA extracted from rhizosphere samples of A. halleri identified microbial taxa (Lysobacter, Streptomyces, Agromyces, Nitrospira, "Candidatus Chloracidobacterium") of higher relative sequence abundance in the rhizospheres of A. halleri plants grown on untreated than on gamma-irradiated soil, leading to hypotheses on their potential effect on plant metal uptake. However, further experimental evidence is required, and wherefore we discuss different mechanisms of interaction of A. halleri with its rhizosphere microbiome that might have directly or indirectly affected plant metal accumulation. Deciphering the complex interactions between A. halleri and individual microbial taxa will help to further develop soil metal phytoextraction as an efficient and sustainable remediation strategy. PMID:25595759

  16. Rhizosphere Microbial Community Composition Affects Cadmium and Zinc Uptake by the Metal-Hyperaccumulating Plant Arabidopsis halleri

    PubMed Central

    Muehe, E. Marie; Weigold, Pascal; Adaktylou, Irini J.; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas

    2015-01-01

    The remediation of metal-contaminated soils by phytoextraction depends on plant growth and plant metal accessibility. Soil microorganisms can affect the accumulation of metals by plants either by directly or indirectly stimulating plant growth and activity or by (im)mobilizing and/or complexing metals. Understanding the intricate interplay of metal-accumulating plants with their rhizosphere microbiome is an important step toward the application and optimization of phytoremediation. We compared the effects of a “native” and a strongly disturbed (gamma-irradiated) soil microbial communities on cadmium and zinc accumulation by the plant Arabidopsis halleri in soil microcosm experiments. A. halleri accumulated 100% more cadmium and 15% more zinc when grown on the untreated than on the gamma-irradiated soil. Gamma irradiation affected neither plant growth nor the 1 M HCl-extractable metal content of the soil. However, it strongly altered the soil microbial community composition and overall cell numbers. Pyrosequencing of 16S rRNA gene amplicons of DNA extracted from rhizosphere samples of A. halleri identified microbial taxa (Lysobacter, Streptomyces, Agromyces, Nitrospira, “Candidatus Chloracidobacterium”) of higher relative sequence abundance in the rhizospheres of A. halleri plants grown on untreated than on gamma-irradiated soil, leading to hypotheses on their potential effect on plant metal uptake. However, further experimental evidence is required, and wherefore we discuss different mechanisms of interaction of A. halleri with its rhizosphere microbiome that might have directly or indirectly affected plant metal accumulation. Deciphering the complex interactions between A. halleri and individual microbial taxa will help to further develop soil metal phytoextraction as an efficient and sustainable remediation strategy. PMID:25595759

  17. Salt tolerant plants increase nitrogen removal from biofiltration systems affected by saline stormwater.

    PubMed

    Szota, Christopher; Farrell, Claire; Livesley, Stephen J; Fletcher, Tim D

    2015-10-15

    Biofiltration systems are used in urban areas to reduce the concentration and load of nutrient pollutants and heavy metals entering waterways through stormwater runoff. Biofilters can, however be exposed to salt water, through intrusion of seawater in coastal areas which could decrease their ability to intercept and retain pollutants. We measured the effect of adding saline stormwater on pollutant removal by six monocotyledonous species with different levels of salt-tolerance. Carex appressa, Carex bichenoviana, Ficinia nodosa, Gahnia filum, Juncus kraussii and Juncus usitatus were exposed to six concentrations of saline stormwater, equivalent to electrical conductivity readings of: 0.09, 2.3, 5.5, 10.4, 20.0 and 37.6 mS cm(-1). Salt-sensitive species: C. appressa, C. bichenoviana and J. usitatus did not survive ≥10.4 mS cm(-1), removing their ability to take up nitrogen (N). Salt-tolerant species, such as F. nodosa and J. kraussii, maintained N-removal even at the highest salt concentration. However, their levels of water stress and stomatal conductance suggest that N-removal would not be sustained at concentrations ≥10.4 mS cm(-1). Increasing salt concentration indirectly increased phosphorus (P) removal, by converting dissolved forms of P to particulate forms which were retained by filter media. Salt concentrations ≥10 mS cm(-1) also reduced removal efficiency of zinc, manganese and cadmium, but increased removal of iron and lead, regardless of plant species. Our results suggest that biofiltration systems exposed to saline stormwater ≤10 mS cm(-1) can only maintain N-removal when planted with salt-tolerant species, while P removal and immobilisation of heavy metals is less affected by species selection. PMID:26150068

  18. Can plant phloem properties affect the link between ecosystem assimilation and respiration?

    NASA Astrophysics Data System (ADS)

    Mencuccini, M.; Hölttä, T.; Sevanto, S.; Nikinmaa, E.

    2012-04-01

    Phloem transport of carbohydrates in plants under field conditions is currently not well understood. This is largely the result of the lack of techniques suitable for measuring phloem physiological properties continuously under field conditions. This lack of knowledge is currently hampering our efforts to link ecosystem-level processes of carbon fixation, allocation and use, especially belowground. On theoretical grounds, the properties of the transport pathway from canopy to roots must be important in affecting the link between carbon assimilation and respiration, but it is unclear whether their effect is partially or entirely masked by processes occurring in other parts of the ecosystem. One can also predict the characteristic time scales over which these effects should occur and, as consequence, predict whether the transfer of turgor and osmotic signals from the site of carbon assimilation to the sites of carbon use are likely to control respiration. We will present two sources of evidence suggesting that the properties of the phloem transport system may affect processes that are dependent on the supply of carbon substrate, such as root or soil respiration. Firstly, we will summarize the results of a literature survey on soil and ecosystem respiration where the speed of transfer of photosynthetic sugars from the plant canopy to the soil surface was determined. Estimates of the transfer speed could be grouped according to whether the study employed isotopic or canopy soil flux-based techniques. These two groups provided very different estimates of transfer times likely because transport of sucrose molecules, and pressure-concentration waves, in phloem differed. Secondly, we will argue that simultaneous measurements of bark and xylem diameters provide a novel tool to determine the continuous variations of phloem turgor in vivo in the field. We will present a model that interprets these changes in xylem and live bark diameters and present data testing the model

  19. The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

    PubMed

    Desurmont, Gaylord A; Zemanova, Miriam A; Turlings, Ted C J

    2016-03-01

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A. vulgaris (invasive) on the survivorship of young Pieris brassicae caterpillars when feeding on Brassica rapa plants, and on plant attractiveness to the main natural enemy of P. brassicae, the parasitoid Cotesia glomerata. In two separate predation experiments, caterpillar mortality was significantly higher on plants co-infested with A. rufus or A. vulgaris. Moreover, caterpillar mortality correlated positively with slug mass and leaf consumption by A. vulgaris. At the third trophic level, plants infested with slugs and plants co-infested with slugs and caterpillars were far less attractive to pa