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Sample records for seed weight variation

  1. Natural variation in ARF18 gene simultaneously affects seed weight and silique length in polyploid rapeseed.

    PubMed

    Liu, Jing; Hua, Wei; Hu, Zhiyong; Yang, Hongli; Zhang, Liang; Li, Rongjun; Deng, Linbin; Sun, Xingchao; Wang, Xinfa; Wang, Hanzhong

    2015-09-15

    Seed weight (SW), which is one of the three major factors influencing grain yield, has been widely accepted as a complex trait that is controlled by polygenes, particularly in polyploid crops. Brassica napus L., which is the second leading crop source for vegetable oil around the world, is a tetraploid (4×) species. In the present study, we identified a major quantitative trait locus (QTL) on chromosome A9 of rapeseed in which the genes for SW and silique length (SL) were colocated. By fine mapping and association analysis, we uncovered a 165-bp deletion in the auxin-response factor 18 (ARF18) gene associated with increased SW and SL. ARF18 encodes an auxin-response factor and shows inhibitory activity on downstream auxin genes. This 55-aa deletion prevents ARF18 from forming homodimers, in turn resulting in the loss of binding activity. Furthermore, reciprocal crossing has shown that this QTL affects SW by maternal effects. Transcription analysis has shown that ARF18 regulates cell growth in the silique wall by acting via an auxin-response pathway. Together, our results suggest that ARF18 regulates silique wall development and determines SW via maternal regulation. In addition, our study reveals the first (to our knowledge) QTL in rapeseed and may provide insights into gene cloning involving polyploid crops.

  2. Natural variation in ARF18 gene simultaneously affects seed weight and silique length in polyploid rapeseed

    PubMed Central

    Liu, Jing; Hua, Wei; Hu, Zhiyong; Yang, Hongli; Zhang, Liang; Li, Rongjun; Deng, Linbin; Sun, Xingchao; Wang, Xinfa; Wang, Hanzhong

    2015-01-01

    Seed weight (SW), which is one of the three major factors influencing grain yield, has been widely accepted as a complex trait that is controlled by polygenes, particularly in polyploid crops. Brassica napus L., which is the second leading crop source for vegetable oil around the world, is a tetraploid (4×) species. In the present study, we identified a major quantitative trait locus (QTL) on chromosome A9 of rapeseed in which the genes for SW and silique length (SL) were colocated. By fine mapping and association analysis, we uncovered a 165-bp deletion in the auxin-response factor 18 (ARF18) gene associated with increased SW and SL. ARF18 encodes an auxin-response factor and shows inhibitory activity on downstream auxin genes. This 55-aa deletion prevents ARF18 from forming homodimers, in turn resulting in the loss of binding activity. Furthermore, reciprocal crossing has shown that this QTL affects SW by maternal effects. Transcription analysis has shown that ARF18 regulates cell growth in the silique wall by acting via an auxin-response pathway. Together, our results suggest that ARF18 regulates silique wall development and determines SW via maternal regulation. In addition, our study reveals the first (to our knowledge) QTL in rapeseed and may provide insights into gene cloning involving polyploid crops. PMID:26324896

  3. Natural variation in ARF18 gene simultaneously affects seed weight and silique length in polyploid rapeseed.

    PubMed

    Liu, Jing; Hua, Wei; Hu, Zhiyong; Yang, Hongli; Zhang, Liang; Li, Rongjun; Deng, Linbin; Sun, Xingchao; Wang, Xinfa; Wang, Hanzhong

    2015-09-15

    Seed weight (SW), which is one of the three major factors influencing grain yield, has been widely accepted as a complex trait that is controlled by polygenes, particularly in polyploid crops. Brassica napus L., which is the second leading crop source for vegetable oil around the world, is a tetraploid (4×) species. In the present study, we identified a major quantitative trait locus (QTL) on chromosome A9 of rapeseed in which the genes for SW and silique length (SL) were colocated. By fine mapping and association analysis, we uncovered a 165-bp deletion in the auxin-response factor 18 (ARF18) gene associated with increased SW and SL. ARF18 encodes an auxin-response factor and shows inhibitory activity on downstream auxin genes. This 55-aa deletion prevents ARF18 from forming homodimers, in turn resulting in the loss of binding activity. Furthermore, reciprocal crossing has shown that this QTL affects SW by maternal effects. Transcription analysis has shown that ARF18 regulates cell growth in the silique wall by acting via an auxin-response pathway. Together, our results suggest that ARF18 regulates silique wall development and determines SW via maternal regulation. In addition, our study reveals the first (to our knowledge) QTL in rapeseed and may provide insights into gene cloning involving polyploid crops. PMID:26324896

  4. Seed coat color and seed weight contribute differential responses of targeted metabolites in soybean seeds.

    PubMed

    Lee, Jinwook; Hwang, Young-Sun; Kim, Sun Tae; Yoon, Won-Byong; Han, Won Young; Kang, In-Kyu; Choung, Myoung-Gun

    2017-01-01

    The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions. PMID:27507473

  5. Endozoochorous seed dispersal by Japanese macaques (Macaca fuscata): Effects of temporal variation in ranging and seed characteristics on seed shadows.

    PubMed

    Tsuji, Yamato; Morimoto, Mayumi

    2016-02-01

    Variation in seed shadows generated by frugivores is caused by daily, seasonal, and inter-annual variation in ranging, as well as inter-specific variability in gut passage times according to seed characteristics. We studied the extent to which seed weight, specific gravity, and daily (morning, afternoon, and evening) and inter-annual (2004 vs. 2005) variation in ranging affected seed shadows generated by wild Japanese macaques (Macaca fuscata) in northern Japan. The macaques ingested fleshy fruits of 11 species during the two year study period; Viburnum dilatatum (Caprifoliaceae: heavier seeds with higher specific gravity) and Rosa multiflora (Rosaceae: lighter seeds with lower specific gravity) were eaten frequently in both years. The travel distances of macaques after feeding on V. dilatatum and R. multiflora fruits were estimated by combining feeding locations and ranging patterns measured in the field with gut passage times of model seeds in captive animals. Median travel distances after fruit feeding were 431 (quantile range: 277-654) and 478 m (265-646), respectively, with a maximum of 1,261 m. Neither year nor time of day affected travel distances. The gut passage time of model V. dilatatum seeds was longer than that of model R. multiflora seed, but this did not affect dispersal distances. Seed shadows for both species over 2 years showed unimodal distribution (peak: 101-500 m) and more than 90%, 20%, and 3% of ingested seeds were estimated to be dispersed >100, >500, and >1000 m, respectively, the longest known distances among macaque species. R. multiflora seeds tended to be dispersed further in 2004 than 2005, but V. dilatatum seeds were not, implying that inter-annual variations in ranging pattern due to the distribution and abundance of nut fruiting could affect dispersal distance.

  6. Seed weight and germination behavior of the submerged plant Potamogeton pectinatus in the arid zone of northwest China

    PubMed Central

    Li, Zhongqiang; Lu, Wei; Yang, Lei; Kong, Xianghong; Deng, Xuwei

    2015-01-01

    Variation in seed weight is common within and among plant species, but few studies have attempted to document the pattern of seed weight and germination attributes for aquatic macrophytes at a large scale. This study examined within-species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant Potamogeton pectinatus in the arid zone of northwest China. Our results showed that the average seed weight was 0.24 g per 100 seeds with a coefficient of variation (CV) of 28.4% among the eight P. pectinatus populations. The total germination fraction of seeds of P. pectinatus was relatively poor, less than 35% in seven P. pectinatus populations, and the lowest germination percentage found was only 2%. There were significant differences in seed weight, time to onset of germination, and total germination fraction among the eight different populations. Hierarchical partitioning analysis showed a strongly positive correlation between seed weight and water temperature and pH. Seed weight and the maternal environmental factors significantly affected both time to initiation of germination and total germination fraction. Our results suggest that (1) seed weight variation in P. pectinatus primarily is the result of temperature variation during fruit development; (2) relatively poor germination fraction suggests that seeds are relatively unimportant in the short-term survival of populations and that it may be another adaptive trait allowing plants to take place in the right place and at the right time, especially in harsh environment; and (3) variation in seed germination traits should be determined by local environmental and intrinsic factors that interact in a complex fashion. PMID:25897389

  7. Seed size variation and its effect on germination and seedling performance in the clonal herb Convallaria majalis

    NASA Astrophysics Data System (ADS)

    Eriksson, Ove

    1999-02-01

    Variation in seed size is common both within and among plant species. This study examined within-species variation in seed weight, and its implications for some components of fitness in the clonal herb Convallaria majalis. This species produces berries containing 4.1 seeds on average. The average seed weight was 16.5 mg, with a coefficient of variation of 32.7%. Seed packaging in fruits was on average 12.5%, and showed a slight tendency to increase with fruit weight. A trade-off was found between seed weight and seed number both within fruits and within ramets. The probability and timing of germination was not influenced by seed size. A field experiment and indirect evidence suggested that post-dispersal seed predation was not related to seed size. Increasing seed weight conferred an advantage to developing seedlings. This advantage was enhanced if a seedling was growing in the close vicinity of a seedling of another species. It is suggested that seed size variation in C. majalis primarily is the result of resource variation during fruit development. A conflict between parents and offspring may however contribute to increase seed size variation.

  8. Florivory Modulates the Seed Number-Seed Weight Relationship in Halenia elliptica (Gentianaceae)

    PubMed Central

    Wang, Linlin; Meng, Lihua; Luo, Jian

    2015-01-01

    Generally, plant reproductive success might be affected negatively by florivory, and the effects may vary depending on the timing and intensity of florivory. To clarify the impacts of florivory by the sawfly larvae (Tenthredinidae) on seed production of Halenia elliptica D. Don, we simulated florivory by removing different proportion of flowers at three reproductive stages in this alpine herb and then examined the seed number per fruit, the seed weight, and the seed mass per fruit of the remaining flowers. Seed number per fruit reduced significantly when flowers were removed at flowering and fruiting stages or when 15% and 60% of flowers were removed. However, seed weight increased significantly after flowers were removed, independent of treatments of reproductive stage and proportion. There was a similar seed mass per fruit between the plants subjected to simulation of florivory and control. The results indicated that florivory modulated the seed number-seed weight relationship in this alpine species. Our study suggested that selective seed abortion and resource reallocation within fruits may ensure fewer but larger seeds, which were expected to be adaptive in the harsh environments. PMID:26495428

  9. The effect of twig architecture and seed number on seed size variation in subtropical woody species.

    PubMed

    Chen, Hong; Niklas, Karl J; Yang, Dongmei; Sun, Shucun

    2009-01-01

    This study aims to determine the effect of twig (current year shoot) size on seed size variation and to test whether a seed size vs number tradeoff occurs for the twigs of subtropical broad-leaved species. Fruit-bearing twigs were sampled for 55 woody species (including 33 evergreen and 22 deciduous dicot species) from a southwest Chinese forest. Twig size, fruit size and number, and seed size and number were measured for each species. The relationships among these functional traits were determined both across species and across correlated phyletic divergences. Total fruit mass and total seed mass were positively correlated with twig size. Seed size was positively associated with fruit size, which was, in turn, positively correlated with twig diameter, but negatively correlated with the ratio of twig length to diameter. The effect of twig size on seed size variation was not significant, possibly as a result of the large variation in seed number per fruit. Cross-species and across-phyletic divergence analyses revealed that seed size was negatively and isometrically correlated with seed number per twig mass in both the evergreen and deciduous species groupings, demonstrating the existence of tradeoff between seed size and number. A seed size vs number tradeoff is detectable in the twigs of woody species. Comparatively little of the variance in seed size was attributable to twig size variation.

  10. Comparative QTL Mapping for Seed Weight Between Ryegrass and Cereals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed weight is one of the most important, complex traits in breeding and domestication process for several major food crops (e.g. rice and wheat). Comparative mapping studies provide insight into the evolution of genome organization within species and the understanding important traits conserved dur...

  11. Evidence for Orthologous Seed Weight Genes in Cowpea and Mung Bean Based on RFLP Mapping

    PubMed Central

    Fatokun, C. A.; Menancio-Hautea, D. I.; Danesh, D.; Young, N. D.

    1992-01-01

    A well saturated genomic map is a necessity for a breeding program based on marker assisted selection. To this end, we are developing genomic maps for cowpea (Vigna unguiculata 2N=22) and mung bean (Vigna radiata 2N=22) based on restriction fragment length polymorphism (RFLP) markers. Using these maps, we have located major quantitative trait loci (QTLs) for seed weight in both species. Two unlinked genomic regions in cowpea contained QTLs accounting for 52.7% of the variation for seed weight. In mung bean there were four unlinked genomic regions accounting for 49.7% of the variation for seed weight. In both cowpea and mung bean the genomic region with the greatest effect on seed weight spanned the same RFLP markers in the same linkage order. This suggests that the QTLs in this genomic region have remained conserved through evolution. This inference is supported by the observation that a significant interaction (i.e., epistasis) was detected between the QTL(s) in the conserved region and an unlinked RFLP marker locus in both species. PMID:1361476

  12. Variation for seed phytosterols in sunflower germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunflower (Helianthus annuus L.) seeds and oils are rich sources of phytosterols, which are important compounds for human nutrition. There is limited information on variability for seed phytosterols in sunflower germplasm. The objective of the present research was to evaluate kernel phytosterol cont...

  13. Exploring the natural variation for seedling traits and their link with seed dimensions in tomato.

    PubMed

    Khan, Noorullah; Kazmi, Rashid H; Willems, Leo A J; van Heusden, Adriaan W; Ligterink, Wilco; Hilhorst, Henk W M

    2012-01-01

    The success of germination, growth and final yield of every crop depends to a large extent on the quality of the seeds used to grow the crop. Seed quality is defined as the viability and vigor attribute of a seed that enables the emergence and establishment of normal seedlings under a wide range of environments. We attempt to dissect the mechanisms involved in the acquisition of seed quality, through a combined approach of physiology and genetics. To achieve this goal we explored the genetic variation found in a RIL population of Solanum lycopersicum (cv. Moneymaker) x Solanum pimpinellifolium through extensive phenotyping of seed and seedling traits under both normal and nutrient stress conditions and root system architecture (RSA) traits under optimal conditions. We have identified 62 major QTLs on 21 different positions for seed, seedling and RSA traits in this population. We identified QTLs that were common across both conditions, as well as specific to stress conditions. Most of the QTLs identified for seedling traits co-located with seed size and seed weight QTLs and the positive alleles were mostly contributed by the S. lycopersicum parent. Co-location of QTLs for different traits might suggest that the same locus has pleiotropic effects on multiple traits due to a common mechanistic basis. We show that seed weight has a strong effect on seedling vigor and these results are of great importance for the isolation of the corresponding genes and elucidation of the underlying mechanisms.

  14. A single gene mutation that increases maize seed weight

    SciTech Connect

    Giroux, M.J.; Shaw, J.; Hannah, L.C. |

    1996-06-11

    The maize endosperm-specific gene shrunken2 (Sh2) encodes the large subunit of the heterotetrameric starch synthetic enzyme adenosine diphosphoglucose pyrophosphorylase (AGP; EC 2.7.7.27). Here we exploit an in vivo, site-specific mutagenesis system to create short insertion mutations in a region of the gene known to be involved in the allosteric regulation of AGP. The site-specific mutagen is the transposable element dissociation (Ds). Approximately one-third (8 of 23) of the germinal revertants sequenced restored the wild-type sequence, whereas the remaining revertants contained insertions of 3 or 6 bp. All revertants retained the original reading frame 3 feet to the insertion site and involved the addition of tyrosine and/or serine. Each insertion revertant reduced total AGP activity and the amount of the SH2 protein. The revertant containing additional tyrosine and serine residues increased seed weight 11-18% without increasing or decreasing the percentage of starch. Other insertion revertants lacking an additional serine reduced seed weight. Reduced sensitivity to phosphate, a long-known inhibitor of AGP, was found in the high seed-weight revertant. This alteration is likely universally important since insertion of tyrosine and serine in the potato large subunit of AGP at the comparable position and expression in Escherichia coli also led to a phosphate-insensitive enzyme. These results show that single gene mutations giving rise to increased seed weight, and therefore perhaps yield, are clearly possible in a plant with a long history of intensive and successful breeding efforts. 20 refs., 5 figs., 5 tabs.

  15. Analysis of interspecies physicochemical variation of grain legume seeds

    NASA Astrophysics Data System (ADS)

    Rybiński, Wojciech; Rusinek, Robert; Szot, Bogusław; Bocianowski, Jan; Starzycki, Michał

    2014-10-01

    The paper presents an attempt to assess the reaction of seeds to mechanical loads taking into account their geometry expressed as seed thickness and 1000 seed weight. The initial material comprised 33 genotypes of grain legume plants and included cultivars registered in the country and breeding lines that are subject to pre-registration trials. The analysis of variance revealed significant diversity of the cultivars and lines of the species studied in terms of each of the analysed trait. The highest weight of 1000 seeds were obtained for white lupine seeds and peas, the lowest for andean lupine seeds. The maximum deformation and energy were obtained for white lupine seeds, the lowest for pea seeds, the maximum force and module the lowest values were determined for narrow-leafed lupine and pea. The highest values of protein were obtained for andean and yellow lupine, a fat content for andean and white lupine. The fatty acid profile as much as 70% or more were linoleic and oleic acids. Against the background of all the species are distinguished by white lupine seeds with a high content of oleic acid and the lowest of linoleic acid, for yellow lupine were obtained the inverse ratio of the two acids.

  16. Genotypic variation in fatty acid content of blackcurrant seeds.

    PubMed

    Ruiz del Castillo, M L; Dobson, G; Brennan, R; Gordon, S

    2002-01-16

    The fatty acid composition and total fatty acid content of seeds from 36 blackcurrant genotypes developed at the Scottish Crop Research Institute were examined. A rapid small-scale procedure, involving homogenization of seeds in toluene followed by sodium methoxide transesterification and gas chromatography, was used. There was considerable variation between genotypes. The gamma-linolenic acid content generally varied from 11 to 19% of the total fatty acids, but three genotypes had higher values of 22-24%, levels previously not reported for blackcurrant seed and similar to those for borage seed. Other nutritionally important fatty acids, stearidonic acid and alpha-linolenic acid, varied from 2 to 4% and 10-19%, respectively. The mean total fatty acid contents ranged from 14 to 23% of the seed, but repeatability was poor. The results are discussed. Blackcurrant seeds are mainly byproducts from juice production, and the study shows the potential for developing blackcurrant genotypes with optimal added value. PMID:11782203

  17. Variation in seed lipids in Calendula germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Calendula officinalis (pot marigold) has considerable promise as an industrial crop, with a long history as an ornamental and medicinal plant. It is also marketed as an ingredient in cosmetics and a colorant. It produces unusual seed lipids, which can provide an additional market for commercial Ca...

  18. Seed size variation in the palm Euterpe edulis and the effects of seed predators on germination and seedling survival

    NASA Astrophysics Data System (ADS)

    Pizo, Marco A.; Von Allmen, Christiane; Morellato, L. Patricia C.

    2006-05-01

    Intraspecific variation in seed size is common in wild plant populations and has important consequences for the reproductive success of individual plants. Multiple, often conflicting evolutionary forces mediated by biotic as well as abiotic agents may maintain such a variation. In this paper we assessed seed size variation in a population of the threatened, commercially important palm Euterpe edulis in southeast Brazil. We investigated (i) how this variation affects the probability of attack by vertebrate and invertebrate post-dispersal seed predators, and (ii) if seed size influences the outcome of seeds damaged by beetles in terms of seed germination and early survival of seedlings. Euterpe edulis seeds varied in diameter from 8.3 to 14.1 mm. Neither insects nor rodents selected the seeds they preyed upon based on seed size. Seed germination and total, shoot and root biomasses of one-year seedlings were significantly and positively affected by seed size. Root biomass and seedling survival were negatively affected by seed damage caused by a scolytid beetle ( Coccotrypes palmarum) whose adults bore into seeds to consume part of the endosperm, but do not oviposit on them. Seed size had a marginally significant effect on seedling survival. Therefore, if any advantage is accrued by E. edulis individuals producing large seeds, this is because of greater seed germination success and seedling vigor. If this is so, even a relatively narrow range of variation in seed size as observed in the E. edulis population studied may translate into differential success of individual plants.

  19. Seasonal Variation in Seed Dispersal by Tamarins Alters Seed Rain in a Secondary Rain Forest

    PubMed Central

    Muñoz Lazo, Fernando Julio João; Huynen, Marie-Claude; Poncin, Pascal; Heymann, Eckhard W.

    2010-01-01

    Reduced dispersal of large seeds into degraded areas is one of the major factors limiting rain forest regeneration, as many seed dispersers capable of transporting large seeds avoid these sites with a limited forest cover. However, the small size of tamarins allows them to use small trees, and hence to disperse seeds into young secondary forests. Seasonal variations in diet and home range use might modify their contribution to forest regeneration through an impact on the seed rain. For a 2-yr period, we followed a mixed-species group of tamarins in Peru to determine how their role as seed dispersers in a 9-yr-old secondary-growth forest varied across seasons. These tamarins dispersed small to large seeds of 166 tree species, 63 of which were into a degraded area. Tamarins’ efficiency in dispersing seeds from primary to secondary forest varied across seasons. During the late wet season, high dietary diversity and long forays in secondary forest allowed them to disperse large seeds involved in later stages of regeneration. This occurred precisely when tamarins spent a more equal amount of time eating a high diversity of fruit species in primary forest and pioneer species in secondary forest. We hypothesized that well-balanced fruit availability induced the movement of seed dispersers between these 2 habitats. The noteworthy number of large-seeded plant species dispersed by such small primates suggests that tamarins play an important, but previously neglected, role in the regeneration and maintenance of forest structure. Electronic supplementary material The online version of this article (doi:10.1007/s10764-010-9413-7) contains supplementary material, which is available to authorized users. PMID:20651905

  20. Genetic mapping and confirmation of quantitative trait loci for seed protein and oil contents and seed weight in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for soybean [Glycine max (L.) Merr.] meal has increased worldwide and soybean importers often offer premiums for soybean containing higher contents of protein and oil. Objectives were to detect quantitative trait loci (QTL) associated with soybean seed protein, oil, and seed weight in a soyb...

  1. Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects

    PubMed Central

    Zas, R; Sampedro, L

    2015-01-01

    Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent–offspring regression using several common garden tests established in contrasting environments to separate G, E and G × E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h2=0.55–0.74). SW showed no apparent G × E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW. PMID:25160045

  2. Heritability of seed weight in Maritime pine, a relevant trait in the transmission of environmental maternal effects.

    PubMed

    Zas, R; Sampedro, L

    2015-01-01

    Quantitative seed provisioning is an important life-history trait with strong effects on offspring phenotype and fitness. As for any other trait, heritability estimates are vital for understanding its evolutionary dynamics. However, being a trait in between two generations, estimating additive genetic variation of seed provisioning requires complex quantitative genetic approaches for distinguishing between true genetic and environmental maternal effects. Here, using Maritime pine as a long-lived plant model, we quantified additive genetic variation of cone and seed weight (SW) mean and SW within-individual variation. We used a powerful approach combining both half-sib analysis and parent-offspring regression using several common garden tests established in contrasting environments to separate G, E and G × E effects. Both cone weight and SW mean showed significant genetic variation but were also influenced by the maternal environment. Most of the large variation in SW mean was attributable to additive genetic effects (h(2)=0.55-0.74). SW showed no apparent G × E interaction, particularly when accounting for cone weight covariation, suggesting that the maternal genotypes actively control the SW mean irrespective of the amount of resources allocated to cones. Within-individual variation in SW was low (12%) relative to between-individual variation (88%), and showed no genetic variation but was largely affected by the maternal environment, with greater variation in the less favourable sites for pine growth. In summary, results were very consistent between the parental and the offspring common garden tests, and clearly indicated heritable genetic variation for SW mean but not for within-individual variation in SW.

  3. Variations of archived static-weight data and WIM

    SciTech Connect

    Elliott, C.J.; Gillmann, R.; Kent, P.M.

    1998-12-01

    Using seven-card archived, static-weight and weigh-in-motion (WIM), truck data received by FHWA for 1966--1992, the authors examine the fluctuations of four fiducial weight measures reported at weight sites in the 50 states. The reduced 172 MB Class 9 (332000) database was prepared and ordered from 2 CD-ROMS with duplicate records removed. Front-axle weight and gross-vehicle weight (GVW) are combined conceptually by determining the front axle weight in four-quartile GVW categories. The four categories of front axle weight from the four GVW categories are combined in four ways. Three linear combinations are with fixed-coefficient fiducials and one is that optimal linear combination producing the smallest standard deviation to mean value ratio. The best combination gives coefficients of variation of 2--3% for samples of 100 trucks, below the expected accuracy of single-event WIM measurements. Time tracking of data shows some high-variation sites have seasonal variations, or linear variations over the time-ordered samples. Modeling of these effects is very site specific but provides a way to reduce high variations. Some automatic calibration schemes would erroneously remove such seasonal or linear variations were they static effects.

  4. Geographic variations in seed dispersal by ants: are plant and seed traits decisive?

    PubMed

    Boulay, R; Coll-Toledano, J; Manzaneda, A J; Cerdá, X

    2007-03-01

    The effect of local ant species on the dispersal success of a myrmecochorous plant, Helleborus foetidus, was analyzed in two populations of the Iberian Peninsula (Caurel and Cazorla, respectively). The contribution of the various local ant species to dispersal was very unequal. While 5 and 19 ant taxa visited the plants of Caurel and Cazorla, respectively, most removal activity (67 and 80%) was performed by two species only (Formica lugubris and Camponotus cruentatus, respectively). Visits by dispersers were also unequally distributed between neighboring plants. While some plants were always visited during the period of seed release, others were never visited. A regression model indicated that this pattern might be explained by two plant traits: ants preferred to visit plants that released more seeds and whose elaiosomes were richer in oleic acid. Although it has long been known that this compound triggers removal by ants, it is the first demonstration that quantitative variations in elaiosome traits contribute to variation in dispersal success. Finally, other variables being equal, morphological traits (seed size, elaiosome size, and elaiosome/seed size ratio) did not affect ant behavior. Although myrmecochory has long been considered a diffuse interaction, our results support the idea that, at local scale, a limited number of ant species may be decisive to its evolution. PMID:17119907

  5. Geographic variations in seed dispersal by ants: are plant and seed traits decisive?

    NASA Astrophysics Data System (ADS)

    Boulay, R.; Coll-Toledano, J.; Manzaneda, A. J.; Cerdá, X.

    2007-03-01

    The effect of local ant species on the dispersal success of a myrmecochorous plant, Helleborus foetidus, was analyzed in two populations of the Iberian Peninsula (Caurel and Cazorla, respectively). The contribution of the various local ant species to dispersal was very unequal. While 5 and 19 ant taxa visited the plants of Caurel and Cazorla, respectively, most removal activity (67 and 80%) was performed by two species only (Formica lugubris and Camponotus cruentatus, respectively). Visits by dispersers were also unequally distributed between neighboring plants. While some plants were always visited during the period of seed release, others were never visited. A regression model indicated that this pattern might be explained by two plant traits: ants preferred to visit plants that released more seeds and whose elaiosomes were richer in oleic acid. Although it has long been known that this compound triggers removal by ants, it is the first demonstration that quantitative variations in elaiosome traits contribute to variation in dispersal success. Finally, other variables being equal, morphological traits (seed size, elaiosome size, and elaiosome/seed size ratio) did not affect ant behavior. Although myrmecochory has long been considered a diffuse interaction, our results support the idea that, at local scale, a limited number of ant species may be decisive to its evolution.

  6. Sequence variations in the FAD2 gene in seeded pumpkins.

    PubMed

    Ge, Y; Chang, Y; Xu, W L; Cui, C S; Qu, S P

    2015-12-21

    Seeded pumpkins are important economic crops; the seeds contain various unsaturated fatty acids, such as oleic acid and linoleic acid, which are crucial for human and animal nutrition. The fatty acid desaturase-2 (FAD2) gene encodes delta-12 desaturase, which converts oleic acid to linoleic acid. However, little is known about sequence variations in FAD2 in seeded pumpkins. Twenty-seven FAD2 clones from 27 accessions of Cucurbita moschata, Cucurbita maxima, Cucurbita pepo, and Cucurbita ficifolia were obtained (totally 1152 bp; a single gene without introns). More than 90% nucleotide identities were detected among the 27 FAD2 clones. Nucleotide substitution, rather than nucleotide insertion and deletion, led to sequence polymorphism in the 27 FAD2 clones. Furthermore, the 27 FAD2 selected clones all encoded the FAD2 enzyme (delta-12 desaturase) with amino acid sequence identities from 91.7 to 100% for 384 amino acids. The same main-function domain between 47 and 329 amino acids was identified. The four species clustered separately based on differences in the sequences that were identified using the unweighted pair group method with arithmetic mean. Geographic origin and species were found to be closely related to sequence variation in FAD2.

  7. Sequence variations in the FAD2 gene in seeded pumpkins.

    PubMed

    Ge, Y; Chang, Y; Xu, W L; Cui, C S; Qu, S P

    2015-01-01

    Seeded pumpkins are important economic crops; the seeds contain various unsaturated fatty acids, such as oleic acid and linoleic acid, which are crucial for human and animal nutrition. The fatty acid desaturase-2 (FAD2) gene encodes delta-12 desaturase, which converts oleic acid to linoleic acid. However, little is known about sequence variations in FAD2 in seeded pumpkins. Twenty-seven FAD2 clones from 27 accessions of Cucurbita moschata, Cucurbita maxima, Cucurbita pepo, and Cucurbita ficifolia were obtained (totally 1152 bp; a single gene without introns). More than 90% nucleotide identities were detected among the 27 FAD2 clones. Nucleotide substitution, rather than nucleotide insertion and deletion, led to sequence polymorphism in the 27 FAD2 clones. Furthermore, the 27 FAD2 selected clones all encoded the FAD2 enzyme (delta-12 desaturase) with amino acid sequence identities from 91.7 to 100% for 384 amino acids. The same main-function domain between 47 and 329 amino acids was identified. The four species clustered separately based on differences in the sequences that were identified using the unweighted pair group method with arithmetic mean. Geographic origin and species were found to be closely related to sequence variation in FAD2. PMID:26782391

  8. Seed predation and climate impacts on reproductive variation in temperate forests of the southeastern USA.

    PubMed

    Bell, David M; Clark, James S

    2016-04-01

    Climatic effects on tree recruitment will be determined by the interactive effects of fecundity and seed predation. Evaluating how insect and vertebrate seed predators mediate tree reproductive responses to climate depends on long-term studies of seed production, development, and predation. In this study, our objectives were to (1) assess the effects of interannual climate variation on seed abortion rates, (2) assess the impact of seed density on predation rates, and (3) examine the degree to which density-dependent seed predation would amplify or dampen interannual variation in fecundity associated with seed abortion. We used a 19-year study of seed abortion and pre-dispersal predation rates by insects and vertebrates (birds and rodents) for five temperate tree species across forest plots from the North Carolina Piedmont to the Southern Appalachian Mountains in the southeastern USA. We found that rates of seed abortion and predation increased reproductive variation for oaks (Quercus species). Probability of seed abortion was greatest during years with cool, dry springs. Responses of seed predation on Quercus species to current year's seed density varied by species, but exhibited positive density-dependence to previous year's seed density consistent with numerical responses of seed predators. Seed abortion and predation rates for two drupe species responded little to variation in climate or seed density, respectively. Given that predation increased interannual variation in seed availability and the negative density-dependence to previous year's seed density, our results indicate that consistent numerical responses of oak seed predators may amplify interannual variation due to climate-mediated processes like seed abortion. PMID:26747267

  9. Predictors of weight variation and weight gain in peri- and post-menopausal women.

    PubMed

    Pimenta, Filipa; Maroco, João; Ramos, Catarina; Leal, Isabel

    2014-08-01

    This research encompasses a community sample of 497 women in peri- and post-menopause and uses structural equation modelling to investigate the structural models of weight variation and weight gain. Variables such as body shape concerns, depression, stress and life events are explored. Weight gain (from pre-menopause to current menopausal status) was observed in 69 per cent of participants. The predictors of weight gain were lower education level (β = -.146, p = .017), less or no physical exercise (β = -.111, p = .021), having a recent psychological problem (β = .191, p < .001), transition from peri- to post-menopause (β = .147, p = .013) and more frequent body shape concerns (β = .313, p < .001). Prevention of weight gain in pre-menopause is recommended; risk groups should be targeted considering the predictors of weight increase.

  10. Genetic variation and seed transfer guidelines for lodgepole pine in Central Oregon. Forest Service research paper

    SciTech Connect

    Sorensen, F.C.

    1992-09-01

    Pine cones were collected from 272 trees at 189 locations uniformly distributed over the east slopes of the Oregon Cascade Range and Warner Mountains. Variation in seed and seedling traits was related to (1) seed source latitude, distance from the Cascade crest, elevation, slope, and aspect in multiple regression analyses; and (2) seed zone and elevation band in classification analyses. Provisional seed transfer guidelines are presented. These include a regression equation for guiding seed transfer and estimating transfer risk, and a new outline of fixed seed zones.

  11. Genetic variation and seed transfer guidelines for ponderosa pine in central Oregon. Forest Service research paper

    SciTech Connect

    Sorensen, F.C.

    1994-07-01

    The report includes an adaptive genetic variation in seed and seedling traits for ponderosa pine from the east slopes of the Cascade Range in Oregon which was analyzed by using 307 families from 227 locations. Factor scores from three principal components based on seed and seedling traits were related by multiple regression to latitude, distance from the Cascade crest, elevation, slope, and aspect of the seed sources and by classification analysis to seed zone and 300-meter elevation band within zone. A provisional transfer risk equation and tentative new seed zones were delineated to guide seed transfer in artificial regeneration.

  12. Patterns of Cross-Continental Variation in Tree Seed Mass in the Canadian Boreal Forest

    PubMed Central

    Liu, Jushan; Bai, Yuguang; Lamb, Eric G.; Simpson, Dale; Liu, Guofang; Wei, Yongsheng; Wang, Deli; McKenney, Daniel W.; Papadopol, Pia

    2013-01-01

    Seed mass is an adaptive trait affecting species distribution, population dynamics and community structure. In widely distributed species, variation in seed mass may reflect both genetic adaptation to local environments and adaptive phenotypic plasticity. Acknowledging the difficulty in separating these two aspects, we examined the causal relationships determining seed mass variation to better understand adaptability and/or plasticity of selected tree species to spatial/climatic variation. A total of 504, 481 and 454 seed collections of black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss) and jack pine (Pinus banksiana Lamb) across the Canadian Boreal Forest, respectively, were selected. Correlation analyses were used to determine how seed mass vary with latitude, longitude, and altitude. Structural Equation Modeling was used to examine how geographic and climatic variables influence seed mass. Climatic factors explained a large portion of the variation in seed mass (34, 14 and 29%, for black spruce, white spruce and jack pine, respectively), indicating species-specific adaptation to long term climate conditions. Higher annual mean temperature and winter precipitation caused greater seed mass in black spruce, but annual precipitation was the controlling factor for white spruce. The combination of factors such as growing season temperature and evapotranspiration, temperature seasonality and annual precipitation together determined seed mass of jack pine. Overall, sites with higher winter temperatures were correlated with larger seeds. Thus, long-term climatic conditions, at least in part, determined spatial variation in seed mass. Black spruce and Jack pine, species with relatively more specific habitat requirements and less plasticity, had more variation in seed mass explained by climate than did the more plastic species white spruce. As traits such as seed mass are related to seedling growth and survival, they potentially

  13. Extensive Natural Variation in Arabidopsis Seed Mucilage Structure

    PubMed Central

    Voiniciuc, Cătălin; Zimmermann, Eva; Schmidt, Maximilian Heinrich-Wilhelm; Günl, Markus; Fu, Lanbao; North, Helen M.; Usadel, Björn

    2016-01-01

    Hydrated Arabidopsis thaliana seeds are coated by a gelatinous layer called mucilage, which is mainly composed of cell wall polysaccharides. Since mucilage is rich in pectin, its architecture can be visualized with the ruthenium red (RR) dye. We screened the seeds of around 280 Arabidopsis natural accessions for variation in mucilage structure, and identified a large number of novel variants that differed from the Col-0 wild-type. Most of the accessions released smaller RR-stained capsules compared to the Col-0 reference. By biochemically characterizing the phenotypes of 25 of these accessions in greater detail, we discovered that distinct changes in polysaccharide structure resulted in gelatinous coatings with a deceptively similar appearance. Monosaccharide composition analysis of total mucilage extracts revealed a remarkable variation (from 50 to 200% of Col-0 levels) in the content of galactose and mannose, which are important subunits of heteromannan. In addition, most of the natural variants had altered Pontamine Fast Scarlet 4B staining of cellulose and significantly reduced birefringence of crystalline structures. This indicates that the production or organization of cellulose may be affected by the presence of different amounts of hemicellulose. Although, the accessions described in this study were primarily collected from Western Europe, they form five different phenotypic classes based on the combined results of our experiments. This suggests that polymorphisms at multiple loci are likely responsible for the observed mucilage structure. The transcription of MUCILAGE-RELATED10 (MUCI10), which encodes a key enzyme for galactoglucomannan synthesis, was severely reduced in multiple variants that phenocopied the muci10-1 insertion mutant. Although, we could not pinpoint any causal polymorphisms in this gene, constitutive expression of fluorescently-tagged MUCI10 proteins complemented the mucilage defects of a muci10-like accession. This leads us to

  14. Comparative quantitative trait loci for silique length and seed weight in Brassica napus.

    PubMed

    Fu, Ying; Wei, Dayong; Dong, Hongli; He, Yajun; Cui, Yixin; Mei, Jiaqin; Wan, Huafang; Li, Jiana; Snowdon, Rod; Friedt, Wolfgang; Li, Xiaorong; Qian, Wei

    2015-09-23

    Silique length (SL) and seed weight (SW) are important yield-associated traits in rapeseed (Brassica napus). Although many quantitative trait loci (QTL) for SL and SW have been identified in B. napus, comparative analysis for those QTL is seldom performed. In the present study, 20 and 21 QTL for SL and SW were identified in doubled haploid (DH) and DH-derived reconstructed F2 populations in rapeseed, explaining 55.1-74.3% and 24.4-62.9% of the phenotypic variation across three years, respectively. Of which, 17 QTL with partially or completely overlapped confidence interval on chromosome A09, were homologous with two overlapped QTL on chromosome C08 by aligning QTL confidence intervals with the reference genomes of Brassica crops. By high density selective genotyping of DH lines with extreme phenotypes, using a Brassica single-nucleotide polymorphism (SNP) array, the QTL on chromosome A09 was narrowed, and aligned into 1.14-Mb region from 30.84 to 31.98 Mb on chromosome R09 of B. rapa and 1.05-Mb region from 27.21 to 28.26 Mb on chromosome A09 of B. napus. The alignment of QTL with Brassica reference genomes revealed homologous QTL on A09 and C08 for SL. The narrowed QTL region provides clues for gene cloning and breeding cultivars by marker-assisted selection.

  15. Comparative quantitative trait loci for silique length and seed weight in Brassica napus

    PubMed Central

    Fu, Ying; Wei, Dayong; Dong, Hongli; He, Yajun; Cui, Yixin; Mei, Jiaqin; Wan, Huafang; Li, Jiana; Snowdon, Rod; Friedt, Wolfgang; Li, Xiaorong; Qian, Wei

    2015-01-01

    Silique length (SL) and seed weight (SW) are important yield-associated traits in rapeseed (Brassica napus). Although many quantitative trait loci (QTL) for SL and SW have been identified in B. napus, comparative analysis for those QTL is seldom performed. In the present study, 20 and 21 QTL for SL and SW were identified in doubled haploid (DH) and DH-derived reconstructed F2 populations in rapeseed, explaining 55.1–74.3% and 24.4–62.9% of the phenotypic variation across three years, respectively. Of which, 17 QTL with partially or completely overlapped confidence interval on chromosome A09, were homologous with two overlapped QTL on chromosome C08 by aligning QTL confidence intervals with the reference genomes of Brassica crops. By high density selective genotyping of DH lines with extreme phenotypes, using a Brassica single-nucleotide polymorphism (SNP) array, the QTL on chromosome A09 was narrowed, and aligned into 1.14-Mb region from 30.84 to 31.98 Mb on chromosome R09 of B. rapa and 1.05-Mb region from 27.21 to 28.26 Mb on chromosome A09 of B. napus. The alignment of QTL with Brassica reference genomes revealed homologous QTL on A09 and C08 for SL. The narrowed QTL region provides clues for gene cloning and breeding cultivars by marker-assisted selection. PMID:26394547

  16. Evolution and association analysis of GmCYP78A10 gene with seed size/weight and pod number in soybean.

    PubMed

    Wang, Xiaobo; Li, Yinhui; Zhang, Haowei; Sun, Genlou; Zhang, Wenming; Qiu, Lijuan

    2015-02-01

    Seed-size/weight traits, controlled by multiple genes in soybean, play an important role in determining seed yield. However, the molecular mechanisms controlling the seed size and weight in soybean remain unclear. In Arabidopsis, P450/CYP78A gene family has been proved extremely relevant to seed size (such as AtCYP78A5, AtCYP78A6 and AtCYP78A9). We found that a soybean GmCYP78A10 gene underwent artificial selection during soybean breeding. The GmCYP78A10a allele mainly distributed in wild soybean (Glycine soja), but has been eliminated in the cultivars during early stage of soybean breeding, while the GmCYP78A10b allele has been accumulated and become the predominant allele in cultivated soybean (G. max). ANOVA analysis showed that the mean seed weight, seed width and seed thickness of soybean varieties with GmCYP78A10b allele was significantly heavier/bigger than those with GmCYP78A10a allele (P < 0.01). The allele could explain 7.2 % variation in seed weight. The pod number of the soybeans with GmCYP78A10b allele significantly decreased compared to those with GmCYP78A10a allele (P < 0.01, R(2) = 5.8 %), while other agronomic traits including seed weight/plant were not significantly affected by these two alleles. We speculated that during the early stage of soybean breeding, breeders selected big seed carrying GmCYP78A10b allele, but lowered pod number simultaneously. Overall, the selection did not cause the significantly change in soybean seed yield. Our results suggests that the soybean GmCYP78A10 gene may have a similar function to those genes belonging to P450/CYP78A subfamily in Arabidopsis and provides new information for the genetic control of seed size in soybean.

  17. Evolution and association analysis of GmCYP78A10 gene with seed size/weight and pod number in soybean.

    PubMed

    Wang, Xiaobo; Li, Yinhui; Zhang, Haowei; Sun, Genlou; Zhang, Wenming; Qiu, Lijuan

    2015-02-01

    Seed-size/weight traits, controlled by multiple genes in soybean, play an important role in determining seed yield. However, the molecular mechanisms controlling the seed size and weight in soybean remain unclear. In Arabidopsis, P450/CYP78A gene family has been proved extremely relevant to seed size (such as AtCYP78A5, AtCYP78A6 and AtCYP78A9). We found that a soybean GmCYP78A10 gene underwent artificial selection during soybean breeding. The GmCYP78A10a allele mainly distributed in wild soybean (Glycine soja), but has been eliminated in the cultivars during early stage of soybean breeding, while the GmCYP78A10b allele has been accumulated and become the predominant allele in cultivated soybean (G. max). ANOVA analysis showed that the mean seed weight, seed width and seed thickness of soybean varieties with GmCYP78A10b allele was significantly heavier/bigger than those with GmCYP78A10a allele (P < 0.01). The allele could explain 7.2 % variation in seed weight. The pod number of the soybeans with GmCYP78A10b allele significantly decreased compared to those with GmCYP78A10a allele (P < 0.01, R(2) = 5.8 %), while other agronomic traits including seed weight/plant were not significantly affected by these two alleles. We speculated that during the early stage of soybean breeding, breeders selected big seed carrying GmCYP78A10b allele, but lowered pod number simultaneously. Overall, the selection did not cause the significantly change in soybean seed yield. Our results suggests that the soybean GmCYP78A10 gene may have a similar function to those genes belonging to P450/CYP78A subfamily in Arabidopsis and provides new information for the genetic control of seed size in soybean. PMID:25324172

  18. Molecular mapping and characterization of genes governing time to flowering, seed weight, and plant height in an intraspecific genetic linkage map of chickpea (Cicer arietinum).

    PubMed

    Jamalabadi, Javad Ghorbani; Saidi, Abbas; Karami, Ezzat; Kharkesh, Mehrab; Talebi, Reza

    2013-06-01

    Drought is the major constraint to chickpea productivity worldwide. Utilizing early flowering genotypes and larger seed size have been suggested as strategies for breeding in drought zones. Therefore, this study aimed to identify potential markers linked to days-to-flowering, 100-seed weight, and plant height in a chickpea intraspecific F(2:3) population derived from the cross ILC3279 × ICCV2. A closely linked marker (TA117) on linkage group LG3 was identified for the days-to-flowering trait, explaining 33% of the variation. In relation to plant height, a quantitative trait loci (QTL) was located in LG3, close to the Ts5 marker, that explained 29% of phenotypic variation. A QTL for 100-seed weight located in LG4, close to TA176, explained 51% of variation. The identification of a locus linked both to high 100-seed weight and days-to-flowering may account for the correlation observed between these traits in this and other breeding attempts.

  19. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L.

    NASA Astrophysics Data System (ADS)

    Ortmans, William; Mahy, Grégory; Monty, Arnaud

    2016-02-01

    Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

  20. Hierarchical Levels of Seed Predation Variation by Introduced Beetles on an Endemic Mediterranean Palm

    PubMed Central

    Rodríguez, Marta; Delibes, Miguel; Fedriani, José Mª.

    2014-01-01

    Seed predators can limit plant recruitment and thus profoundly impinge the dynamics of plant populations, especially when diverse seed predators (e.g., native and introduced) attack particular plant populations. Surprisingly, however, we know little concerning the potential hierarchy of spatial scales (e.g., region, population, patch) and coupled ecological correlates governing variation in the overall impact that native and introduced seed predators have on plant populations. We investigated several spatial scales and ecological correlates of pre-dispersal seed predation by invasive borer beetles in Chamaerops humilis (Arecaceae), a charismatic endemic palm of the Mediteranean basin. To this end, we considered 13 palm populations (115 palms) within four geographical regions of the Iberian Peninsula. The observed interregional differences in percentages of seed predation by invasive beetles were not significant likely because of considerable variation among populations within regions. Among population variation in seed predation was largely related to level of human impact. In general, levels of seed predation were several folds higher in human-altered populations than in natural populations. Within populations, seed predation declined significantly with the increase in amount of persisting fruit pulp, which acted as a barrier against seed predators. Our results revealed that a native species (a palm) is affected by the introduction of related species because of the concurrent introduction of seed predators that feed on both the introduced and native palms. We also show how the impact of invasive seed predators on plants can vary across a hierarchy of levels ranging from variation among individuals within local populations to large scale regional divergences. PMID:25340462

  1. Variation in Weed Seed Fate Fed to Different Holstein Cattle Groups.

    PubMed

    Rahimi, Salman; Mashhadi, Hamid Rahimian; Banadaky, Mehdi Dehghan; Mesgaran, Mohsen Beheshtian

    2016-01-01

    Weed seeds may maintain their viability when passing through the digestive tract of cattle and can be therefore dispersed by animal movement or the application of manure. Whether different cattle types of the same species can cause differential weed seed fate is largely unknown to us particularly under non-grazed systems similar to Holstein-Friesian dairy farming. We investigated the effect on the seed survival of four weed species in the digestive tracts of four groups of Holstein cattle: lactating cows, feedlot male calves, dry cows and growing heifers. The weed species used were Cuscuta campestris, Polygonum aviculare, Rumex crispus and Sorghum halepense. Cattle excretion was sampled for recovery and viability of seeds at four 24 hourly intervals after seed intake. The highest seed recovery occurred two days after seed intake in all cattle groups. Averaged over weed species, dry and lactating cows had the lowest and highest seed recovery of 36.4% and 74.4% respectively. No significant differences were observed in seed recovery of the four weed species when their seeds were fed to dry cows. Based on a power model fitted to seed viability data, the estimated time to 50% viability loss after seed intake, over all cattle groups ranged from 65 h (R. crispus) to 76 h (P. aviculare). Recovered seeds from the dung of feedlot male calves showed the highest mortality among cattle groups. Significant correlation was found between seed viability and ruminal pH (r = 0.86; P<0.05). This study shows that management programs aiming to minimize weed infestation caused by livestock should account for the variation amongst cattle groups in seed persistence. Our findings can be used as a guideline for evaluating the potential risk of the spread of weeds via the application of cattle manure.

  2. Variation in Weed Seed Fate Fed to Different Holstein Cattle Groups.

    PubMed

    Rahimi, Salman; Mashhadi, Hamid Rahimian; Banadaky, Mehdi Dehghan; Mesgaran, Mohsen Beheshtian

    2016-01-01

    Weed seeds may maintain their viability when passing through the digestive tract of cattle and can be therefore dispersed by animal movement or the application of manure. Whether different cattle types of the same species can cause differential weed seed fate is largely unknown to us particularly under non-grazed systems similar to Holstein-Friesian dairy farming. We investigated the effect on the seed survival of four weed species in the digestive tracts of four groups of Holstein cattle: lactating cows, feedlot male calves, dry cows and growing heifers. The weed species used were Cuscuta campestris, Polygonum aviculare, Rumex crispus and Sorghum halepense. Cattle excretion was sampled for recovery and viability of seeds at four 24 hourly intervals after seed intake. The highest seed recovery occurred two days after seed intake in all cattle groups. Averaged over weed species, dry and lactating cows had the lowest and highest seed recovery of 36.4% and 74.4% respectively. No significant differences were observed in seed recovery of the four weed species when their seeds were fed to dry cows. Based on a power model fitted to seed viability data, the estimated time to 50% viability loss after seed intake, over all cattle groups ranged from 65 h (R. crispus) to 76 h (P. aviculare). Recovered seeds from the dung of feedlot male calves showed the highest mortality among cattle groups. Significant correlation was found between seed viability and ruminal pH (r = 0.86; P<0.05). This study shows that management programs aiming to minimize weed infestation caused by livestock should account for the variation amongst cattle groups in seed persistence. Our findings can be used as a guideline for evaluating the potential risk of the spread of weeds via the application of cattle manure. PMID:27104783

  3. Variation in Weed Seed Fate Fed to Different Holstein Cattle Groups

    PubMed Central

    Mesgaran, Mohsen Beheshtian

    2016-01-01

    Weed seeds may maintain their viability when passing through the digestive tract of cattle and can be therefore dispersed by animal movement or the application of manure. Whether different cattle types of the same species can cause differential weed seed fate is largely unknown to us particularly under non-grazed systems similar to Holstein-Friesian dairy farming. We investigated the effect on the seed survival of four weed species in the digestive tracts of four groups of Holstein cattle: lactating cows, feedlot male calves, dry cows and growing heifers. The weed species used were Cuscuta campestris, Polygonum aviculare, Rumex crispus and Sorghum halepense. Cattle excretion was sampled for recovery and viability of seeds at four 24 hourly intervals after seed intake. The highest seed recovery occurred two days after seed intake in all cattle groups. Averaged over weed species, dry and lactating cows had the lowest and highest seed recovery of 36.4% and 74.4% respectively. No significant differences were observed in seed recovery of the four weed species when their seeds were fed to dry cows. Based on a power model fitted to seed viability data, the estimated time to 50% viability loss after seed intake, over all cattle groups ranged from 65 h (R. crispus) to 76 h (P. aviculare). Recovered seeds from the dung of feedlot male calves showed the highest mortality among cattle groups. Significant correlation was found between seed viability and ruminal pH (r = 0.86; P<0.05). This study shows that management programs aiming to minimize weed infestation caused by livestock should account for the variation amongst cattle groups in seed persistence. Our findings can be used as a guideline for evaluating the potential risk of the spread of weeds via the application of cattle manure. PMID:27104783

  4. Drude and Superconducting Weights and Mott Transitions in Variation Theory

    NASA Astrophysics Data System (ADS)

    Tamura, Shun; Yokoyama, Hisatoshi

    2015-06-01

    The Drude weight (D) is a useful measure for distinguishing a metal from an insulator. However, D has not been justifiably estimated using variation theory for a long time, since Millis and Coppersmith [Phys. Rev. B 43, 13770 (1991)] pointed out that the variational wave function ΨQ, which includes the key ingredient (doublon-holon binding effect) for a Mott transition, yields a positive D (namely, metallic) even in the Mott insulating regime. We argue that, to obtain a correct D, an imaginary part must exist in the wave function. By introducing a configuration-dependent phase factor Pθ to ΨQ, Mott transitions are successfully represented by D (D = 0 for U > Uc) for normal and d-wave pairing states; thus, the problem of Millis and Coppersmith is solved. Generally, Pθ plays a pivotal role in describing current-carrying states in the regime of Mott physics. On the other hand, we show using perturbation theory that the one-body (mean-field) part of the wave function should be complex for band insulators such as antiferromagnetic states in hypercubic lattices.

  5. Consistency and variation in phenotypic selection exerted by a community of seed predators.

    PubMed

    Benkman, Craig W; Smith, Julie W; Maier, Monika; Hansen, Leif; Talluto, Matt V

    2013-01-01

    Phenotypic selection that is sustained over time underlies both anagenesis and cladogenesis, but the conditions that lead to such selection and what causes variation in selection are not well known. We measured the selection exerted by three species of predispersal seed predators of lodgepole pine (Pinus contorta latifolia) in the South Hills, Idaho, and found that net selection on different cone and seed traits exerted by red crossbills (Loxia curvirostra) and cone borer moths (Eucosma recissoriana) over 10 years of seed crops was similar to that measured in another mountain range. We also found that the strength of selection increased as seed predation increased, which provides a mechanism for the correlation between the escalation of seed defenses and the density of seed predators. Red crossbills consume the most seeds and selection they exert accounts for much of the selection experienced by lodgepole pine, providing additional support for a coevolutionary arms race between crossbills and lodgepole pine in the South Hills. The third seed predator, hairy woodpeckers (Picoides villosus), consumed less than one-sixth as many seeds as crossbills. Across the northern Rocky Mountains, woodpecker abundance and therefore selective impact appears limited by the elevated seed defenses of lodgepole pine. PMID:23289569

  6. Consistency and variation in phenotypic selection exerted by a community of seed predators.

    PubMed

    Benkman, Craig W; Smith, Julie W; Maier, Monika; Hansen, Leif; Talluto, Matt V

    2013-01-01

    Phenotypic selection that is sustained over time underlies both anagenesis and cladogenesis, but the conditions that lead to such selection and what causes variation in selection are not well known. We measured the selection exerted by three species of predispersal seed predators of lodgepole pine (Pinus contorta latifolia) in the South Hills, Idaho, and found that net selection on different cone and seed traits exerted by red crossbills (Loxia curvirostra) and cone borer moths (Eucosma recissoriana) over 10 years of seed crops was similar to that measured in another mountain range. We also found that the strength of selection increased as seed predation increased, which provides a mechanism for the correlation between the escalation of seed defenses and the density of seed predators. Red crossbills consume the most seeds and selection they exert accounts for much of the selection experienced by lodgepole pine, providing additional support for a coevolutionary arms race between crossbills and lodgepole pine in the South Hills. The third seed predator, hairy woodpeckers (Picoides villosus), consumed less than one-sixth as many seeds as crossbills. Across the northern Rocky Mountains, woodpecker abundance and therefore selective impact appears limited by the elevated seed defenses of lodgepole pine.

  7. Construction of a Genetic Linkage Map and Identification of QTLs for Seed Weight and Seed Size Traits in Lentil (Lens culinaris Medik.).

    PubMed

    Verma, Priyanka; Goyal, Richa; Chahota, R K; Sharma, Tilak R; Abdin, M Z; Bhatia, Sabhyata

    2015-01-01

    Seed weight and seed size both are quantitative traits and have been considered as important components of grain yield, thus identification of quantitative trait loci (QTL) for seed traits in lentil (Lens culinaris) would be beneficial for the improvement of grain yield. Hence the main objective of this study was to identify QTLs for seed traits using an intraspecific mapping population derived from a cross between L. culinaris cv. Precoz (seed weight-5.1g, seed size-5.7mm) and L. culinaris cv. L830 (seed weight-2.2g, seed size-4mm) comprising 126 F8-RILs. For this, two microsatellite genomic libraries enriched for (GA/CT) and (GAA/CTT) motif were constructed which resulted in the development of 501 new genomic SSR markers. Six hundred forty seven SSR markers (including 146 previously published) were screened for parental polymorphism and 219 (33.8%) were found to be polymorphic among the parents. Of these 216 were mapped on seven linkage groups at LOD4.0 spanning 1183.7cM with an average marker density of 5.48cM. Phenotypic data from the RILs was used to identify QTLs for the seed weight and seed size traits by single marker analysis (SMA) followed by composite interval mapping (CIM) which resulted in one QTL each for the 2 traits (qSW and qSS) that were co-localized on LG4 and explained 48.4% and 27.5% of phenotypic variance respectively. The current study would serve as a strong foundation for further validation and fine mapping for utilization in lentil breeding programs.

  8. Construction of a Genetic Linkage Map and Identification of QTLs for Seed Weight and Seed Size Traits in Lentil (Lens culinaris Medik.).

    PubMed

    Verma, Priyanka; Goyal, Richa; Chahota, R K; Sharma, Tilak R; Abdin, M Z; Bhatia, Sabhyata

    2015-01-01

    Seed weight and seed size both are quantitative traits and have been considered as important components of grain yield, thus identification of quantitative trait loci (QTL) for seed traits in lentil (Lens culinaris) would be beneficial for the improvement of grain yield. Hence the main objective of this study was to identify QTLs for seed traits using an intraspecific mapping population derived from a cross between L. culinaris cv. Precoz (seed weight-5.1g, seed size-5.7mm) and L. culinaris cv. L830 (seed weight-2.2g, seed size-4mm) comprising 126 F8-RILs. For this, two microsatellite genomic libraries enriched for (GA/CT) and (GAA/CTT) motif were constructed which resulted in the development of 501 new genomic SSR markers. Six hundred forty seven SSR markers (including 146 previously published) were screened for parental polymorphism and 219 (33.8%) were found to be polymorphic among the parents. Of these 216 were mapped on seven linkage groups at LOD4.0 spanning 1183.7cM with an average marker density of 5.48cM. Phenotypic data from the RILs was used to identify QTLs for the seed weight and seed size traits by single marker analysis (SMA) followed by composite interval mapping (CIM) which resulted in one QTL each for the 2 traits (qSW and qSS) that were co-localized on LG4 and explained 48.4% and 27.5% of phenotypic variance respectively. The current study would serve as a strong foundation for further validation and fine mapping for utilization in lentil breeding programs. PMID:26436554

  9. Quantitative Genetics Identifies Cryptic Genetic Variation Involved in the Paternal Regulation of Seed Development.

    PubMed

    Pires, Nuno D; Bemer, Marian; Müller, Lena M; Baroux, Célia; Spillane, Charles; Grossniklaus, Ueli

    2016-01-01

    Embryonic development requires a correct balancing of maternal and paternal genetic information. This balance is mediated by genomic imprinting, an epigenetic mechanism that leads to parent-of-origin-dependent gene expression. The parental conflict (or kinship) theory proposes that imprinting can evolve due to a conflict between maternal and paternal alleles over resource allocation during seed development. One assumption of this theory is that paternal alleles can regulate seed growth; however, paternal effects on seed size are often very low or non-existent. We demonstrate that there is a pool of cryptic genetic variation in the paternal control of Arabidopsis thaliana seed development. Such cryptic variation can be exposed in seeds that maternally inherit a medea mutation, suggesting that MEA acts as a maternal buffer of paternal effects. Genetic mapping using recombinant inbred lines, and a novel method for the mapping of parent-of-origin effects using whole-genome sequencing of segregant bulks, indicate that there are at least six loci with small, paternal effects on seed development. Together, our analyses reveal the existence of a pool of hidden genetic variation on the paternal control of seed development that is likely shaped by parental conflict.

  10. Quantitative Genetics Identifies Cryptic Genetic Variation Involved in the Paternal Regulation of Seed Development

    PubMed Central

    Pires, Nuno D.; Bemer, Marian; Müller, Lena M.; Baroux, Célia; Spillane, Charles; Grossniklaus, Ueli

    2016-01-01

    Embryonic development requires a correct balancing of maternal and paternal genetic information. This balance is mediated by genomic imprinting, an epigenetic mechanism that leads to parent-of-origin-dependent gene expression. The parental conflict (or kinship) theory proposes that imprinting can evolve due to a conflict between maternal and paternal alleles over resource allocation during seed development. One assumption of this theory is that paternal alleles can regulate seed growth; however, paternal effects on seed size are often very low or non-existent. We demonstrate that there is a pool of cryptic genetic variation in the paternal control of Arabidopsis thaliana seed development. Such cryptic variation can be exposed in seeds that maternally inherit a medea mutation, suggesting that MEA acts as a maternal buffer of paternal effects. Genetic mapping using recombinant inbred lines, and a novel method for the mapping of parent-of-origin effects using whole-genome sequencing of segregant bulks, indicate that there are at least six loci with small, paternal effects on seed development. Together, our analyses reveal the existence of a pool of hidden genetic variation on the paternal control of seed development that is likely shaped by parental conflict. PMID:26811909

  11. Quantitative Genetics Identifies Cryptic Genetic Variation Involved in the Paternal Regulation of Seed Development.

    PubMed

    Pires, Nuno D; Bemer, Marian; Müller, Lena M; Baroux, Célia; Spillane, Charles; Grossniklaus, Ueli

    2016-01-01

    Embryonic development requires a correct balancing of maternal and paternal genetic information. This balance is mediated by genomic imprinting, an epigenetic mechanism that leads to parent-of-origin-dependent gene expression. The parental conflict (or kinship) theory proposes that imprinting can evolve due to a conflict between maternal and paternal alleles over resource allocation during seed development. One assumption of this theory is that paternal alleles can regulate seed growth; however, paternal effects on seed size are often very low or non-existent. We demonstrate that there is a pool of cryptic genetic variation in the paternal control of Arabidopsis thaliana seed development. Such cryptic variation can be exposed in seeds that maternally inherit a medea mutation, suggesting that MEA acts as a maternal buffer of paternal effects. Genetic mapping using recombinant inbred lines, and a novel method for the mapping of parent-of-origin effects using whole-genome sequencing of segregant bulks, indicate that there are at least six loci with small, paternal effects on seed development. Together, our analyses reveal the existence of a pool of hidden genetic variation on the paternal control of seed development that is likely shaped by parental conflict. PMID:26811909

  12. Neonatal birth weight variations between inland and littoral Croatia.

    PubMed

    Bralić, Irena; Rodin, Urelija; Matanić, Dubravka; Jovancevic, Milivoj

    2010-09-01

    The aim of the study was to assess neonatal birth weight (BW) differences between inland and littoral Croatia, to identify BW groups with most pronounced differences, and possible variations in the rate of BW > or = 4000 g between Sibenik area and the rest of littoral (counties with access to the Adriatic Sea) and inland Croatia. The study included data on 99.42% of 200,740 live births recorded in 37 Croatian maternity hospitals during the 2001-2005 period. Distribution of 500-g BW groups was analyzed irrespective of neonatal sex and gestational age. Differences were found between the inland and littoral parts of Croatia according to distribution of the BW groups of < 2500 g (5.4% vs. 4.4%), 2500-3999 g (84% vs. 80.2%) and > or = 4000 g (10.6% vs. 15.4%) (chi2 = 882; p < 0.001).The highest rate of BW > or = 4000 g was recorded in Sibenik-Knin County (5-year mean 18.32%) and was greater throughout the littoral as compared with inland Croatia (5-year mean 14.99% vs. 9.58%). A shift towards higher BWgroups recorded throughout littoral as compared with inland Croatia supports the hypothesis on variation in anthropologic characteristics in the respective populations to be pronounced as early as at birth. Study results confirmed fetal macrosomia not to be exclusively characteristic of Sibenik-Knin County, since the rate of neonatal BW > or =4000 g was significantly higher in the entire littoral as compared with inland Croatia.

  13. New NIRS calibrations for fiber fractions reveal broad genetic variation in Brassica napus seed quality.

    PubMed

    Wittkop, Benjamin; Snowdon, Rod J; Friedt, Wolfgang

    2012-03-01

    Near-infrared reflectance spectroscopy (NIRS) calibrations were developed for the estimation of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) in intact seeds of oilseed rape ( Brassica napus ). A set of 338 diverse winter oilseed rape genotypes showing broad variation for seed color was used as a basis for the new calibrations. Different calibrations were generated for 10 or 1 mL seed volumes, respectively. In both seed volumes good coefficients of determination for external validation (R(2)) of the calibrations were obtained for ADL, the major antinutritional fiber fraction in oilseed rape meal, and adequate calibrations for NDF and ADF. Evaluation of diverse B. napus germplasm with the new calibrations revealed a surprisingly broad variation in contents of ADL in dark-seeded oilseed rape. The ability to use NIRS for efficient selection of low-fiber genotypes, irrespective of seed color, represents an important breakthrough in breeding for improved nutritional quality of seed extraction meals from oilseed rape. PMID:22296210

  14. Characteristics and bioactivities of different molecular weight polysaccharides from camellia seed cake.

    PubMed

    Xu, Zhou; Li, Xu; Feng, Shiling; Liu, Jing; Zhou, Lijun; Yuan, Ming; Ding, Chunbang

    2016-10-01

    Four polysaccharides, namely COP-1, COP-2, COP-3 and COP-4, were ultrafiltrated from crud Camellia oleifera seed cake polysaccharides (COP-c), purified, and characterized, including the determination of antioxidant and antiproliferative activities. Their molecular weights were 7.9, 36, 83 and 225kDa, respectively. All COPs showed the similar FT-IR spectrums, but significant differentials in monosaccharide components. COP-2 exhibited the highest radical scavenging abilities. COP-1 has the strongest metal chelating capabilities. Although with higher molecular weight, COP-4 showed the poorest antioxidant abilities. These results suggested appreciate molecular weight COP possessed a better antioxidant activities. Additionally, all COPs had non-significant antiproliferative abilities in HaLa and HepG2 cells.

  15. Relationships Between Seed Weight, Germination Potential and Biochemical Reserves of Maritime Pine in Morocco: Elements for Tree Seedlings Improvement

    NASA Technical Reports Server (NTRS)

    Wahid, Nadya; Bounoua, Lahouari

    2011-01-01

    Selection of quality seeds in breeding programs can significantly improve seedling productivity. Germination and biochemical analyses on seeds from ten natural populations of maritime pine (Pinus pinaster Ait.) in Morocco reveals significant differences among populations in seed weight, germination characters and protein content in both dry seeds and megagametophytes. During germination, the mobilization of protein content in megagametophyte is significantly different among populations than sugar content. A strong positive correlation between the germination capacity and the protein content in both dry seeds and megagametophytes indicates that the best populations in term of germination capacity may also be the richest in protein content. The present study finds that seed weight is not a good indicator for quality seed selection, nor is it recommended to increase the degree of germinability. Our results suggest that the pine population in southern Morocco might have adapted to drought conditions as it is characterized by heavy seed weight and lower speed of protein content mobilization in megagametophyte compared to northern populations growing in temperate climate.

  16. Effects of steckling weight and planting density on sugar beet (Beta vulgaris L.) monogerm seed yield and qualitative traits.

    PubMed

    Hemayati, Saeed Sadeghzadeh; Taleghani, Daryoush Fatollah; Shahmoradi, Shima

    2008-01-15

    In order to determine the effects of steckling weight and planting density on sugar beet monogerm (Cv. 9597) seed quantitative and qualitative characteristics, this experiment was carried out in Ardabil Agricultural Research Station-Iran (38 degrees 30'N and 48 degrees 30'E) during 2 years (2002-2003). In the study, steckling weight (main-plot) in three levels including 100, 100-200 and 200-300 g and planting density (sub-plot) in three levels including 40, 50 and 60 cm were used in a split-plot experiment based on the RCBD (Randomized Complete Blocks Design) with 5 replications. The measured characteristics were morphological and qualitative (velocity and uniformity of germination) characters, seed size distribution and monogerm seed percentage. According to the results of the experiment, the effect of planting density on the auxiliary branches No. and seed yield was significant at the probability levels of 1 and 5%, respectively. Seed yield increased by 43% as planting density was increased from 65 x 40 to 65 x 60 cm. The increase in steckling weight led to the increase in standard seed portion (with 3.5-4.5 mm in diameter), germinable standard seed yield (11%) and decrease in germination velocity and germination uniformity; and increase in planting density was accompanied by increase in > 4.5 mm seed percentage, velocity and uniformity of germination and decrease in germinable standard seed yield. Eventually, the highest seed yield (1208 kg ha(-1)) was obtained by using steckling weight of 200-300 g and planting density of 65 x 60 cm.

  17. Drivers of Spatial Variation in the Role of Ants as Secondary Seed Dispersers.

    PubMed

    Bottcher, C; Peixoto, P E C; Silva, W R; Pizo, M A

    2016-08-01

    The spatial variation in the outcome of the interaction between secondary dispersers and seeds is superimposed upon the variation produced by primary dispersers. Investigating the factors that drive the outcome of the interactions with secondary seed dispersers thus represents an essential refinement to our understanding of the complete seed dispersal process. We studied the interactions between two ponerine ants (Pachycondyla striata Smith, 1858 and Odontomachus chelifer (Latreille, 1802)) with fruits experimentally set on the ground, and estimated the effects of ants on seedling establishment in three areas distributed along a 2-km stretch of a Brazilian Atlantic rainforest that differ in soil properties and vegetation physiognomies. We tested the hypothesis that interactions are more frequent, resulting in greater seedling establishment at the site with harsher abiotic and biotic conditions. Both ant species removed fruits frequently and have a positive effect on seedling establishment in all study areas, but fruit removal did not differ among areas, while seedling establishment was more pronounced at the site with stressful abiotic conditions. The two ant species differed in important aspects of their seed dispersal services, including the propensity to interact with seeds. As a result, both the species of ant and abiotic conditions interact at the scale of 2 km to determine the fate of seeds interacting with ants, thus creating a mosaic of outcomes with variable benefits to plants. PMID:27298391

  18. Extraction, Characterization, and Molecular Weight Determination of Senna tora (L.) Seed Polysaccharide

    PubMed Central

    Pawar, Harshal A.; Lalitha, K. G.

    2015-01-01

    The objective of the present work was extraction of polysaccharide from Senna tora L. seed and its characterization as a pharmaceutical excipient. Polysaccharide extraction was based on mechanical separation of the endosperm of seeds of Senna tora, water dissolution, centrifugation, and precipitation with acetone. Standard procedures were used to study the viscosity, micromeritic properties, and microbial bioburden. Accelerated stability study was carried out on isolated polysaccharide for six months at 40°C/75 RH as per ICH guidelines. The gum obtained from S. tora seeds was an amorphous free flowing odourless powder with dull brown colour (yield = 35% w/w). The bulk density, tapped density, and angle of repose data reveal that S. tora gum possesses good flow property. The intrinsic viscosity obtained was 1.568 dL/g. The average molecular weight of purified S. tora gum was found to be 198 kDa by intrinsic viscosity method. The results indicated that viscosity of gum solution increases with increase in temperature. FTIR study revealed the absence of degradation or decomposition of polysaccharide at accelerated stability conditions for six months. It has been concluded that extracted polysaccharide can be used as pharmaceutical excipient in terms of flow behavior, microbial properties, and stability. PMID:26640490

  19. Free volume variation with molecular weight of polymers

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Eftekhari, Abe; Hinkley, Jeffrey A.; St.clair, Terry L.; Jensen, Brian J.

    1992-01-01

    Free volume measurements were made in several molecular weight fractions of two different geometries of poly(arylene ether ketone)s. Free volumes were measured using positron lifetime spectroscopy. It has been observed that the free volume cell size V(sub f) varies with the molecular weight M of the test samples according to an equation of the form V(sub f) = AM(B), where A and B are constants. The molecular weights computed from the free volume cell sizes are in good agreement with the values measured by gel permeation chromatography.

  20. Weighted sequence motifs as an improved seeding step in microRNA target prediction algorithms.

    PubMed

    Saetrom, Ola; Snøve, Ola; Saetrom, Pål

    2005-07-01

    We present a new microRNA target prediction algorithm called TargetBoost, and show that the algorithm is stable and identifies more true targets than do existing algorithms. TargetBoost uses machine learning on a set of validated microRNA targets in lower organisms to create weighted sequence motifs that capture the binding characteristics between microRNAs and their targets. Existing algorithms require candidates to have (1) near-perfect complementarity between microRNAs' 5' end and their targets; (2) relatively high thermodynamic duplex stability; (3) multiple target sites in the target's 3' UTR; and (4) evolutionary conservation of the target between species. Most algorithms use one of the two first requirements in a seeding step, and use the three others as filters to improve the method's specificity. The initial seeding step determines an algorithm's sensitivity and also influences its specificity. As all algorithms may add filters to increase the specificity, we propose that methods should be compared before such filtering. We show that TargetBoost's weighted sequence motif approach is favorable to using both the duplex stability and the sequence complementarity steps. (TargetBoost is available as a Web tool from http://www.interagon.com/demo/.).

  1. Chia seed does not promote weight loss or alter disease risk factors in overweight adults.

    PubMed

    Nieman, David C; Cayea, Erin J; Austin, Melanie D; Henson, Dru A; McAnulty, Steven R; Jin, Fuxia

    2009-06-01

    The objective of this study was to assess the effectiveness of chia seed (Salvia hispanica L) in promoting weight loss and altering disease risk factors in overweight adults. The hypothesis was that the high dietary fiber and alpha-linolenic (ALA) contents of chia seed would induce a small but significant decrease in body weight and fat and improve disease risk factors. Subjects were randomized to chia seed (CS) and placebo (P) groups, and under single-blinded procedures, ingested 25 g CS or P supplements mixed in 0.25 L water twice daily before the first and last meal for 12 weeks. Ninety nondiseased, overweight/obese men and women between the ages of 20 and 70 years were recruited into the study, with 76 subjects (n = 39 CS, n = 37 P) completing all phases of the study. Pre- and poststudy measures included body mass and composition (dual energy x-ray absorptiometry), inflammation markers from fasting blood samples (C-reactive protein, interleukin 6, monocyte chemoattractant protein 1, and tumor necrosis factor alpha), oxidative stress markers (trolox equivalent antioxidant capacity and plasma nitrite), blood pressure, and a serum lipid profile. Plasma ALA increased 24.4% compared to a 2.8% decrease in CS and P, respectively (interaction effect, P = .012). No group differences were measured for changes in plasma eicosapentaenoic acid and docosahexaenoic acid (interaction effects, P = .420 and .980, respectively). Pre-to-post measures of body composition, inflammation, oxidative stress, blood pressure, and lipoproteins did not differ between CS and P for both sexes. In conclusion, ingestion of 50 g/d CS vs P for 12 weeks by overweight/obese men and women had no influence on body mass or composition, or various disease risk factor measures.

  2. Assessment of the natural variation of low abundant metabolic proteins in soybean seeds using proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, we investigated the distribution of the low abundant proteins that are involved in soybean seed development in four wild and twelve cultivated soybean genotypes. We found proteomic variation of these proteins within and...

  3. Genetic and Sequence Analysis of Genes Controlling Natural Variation of Seed-Coat and Flower Colors in Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soybean exhibits natural variation in flower and seed-coat colors via the deposition of various anthocyanin pigments in the respective tissues. Although pigmentation in seeds or flowers has been well dissected at molecular level in several plant species, the genes controlling natural variation ...

  4. Seed metabolomic study reveals significant metabolite variations and correlations among different soybean cultivars.

    PubMed

    Lin, Hong; Rao, Jun; Shi, Jianxin; Hu, Chaoyang; Cheng, Fang; Wilson, Zoe A; Zhang, Dabing; Quan, Sheng

    2014-09-01

    Soybean [Glycine max (L.) Merr.] is one of the world's major crops, and soybean seeds are a rich and important resource for proteins and oils. While "omics" studies, such as genomics, transcriptomics, and proteomics, have been widely applied in soybean molecular research, fewer metabolomic studies have been conducted for large-scale detection of low molecular weight metabolites, especially in soybean seeds. In this study, we investigated the seed metabolomes of 29 common soybean cultivars through combined gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. One hundred sixty-nine named metabolites were identified and subsequently used to construct a metabolic network of mature soybean seed. Among the 169 detected metabolites, 104 were found to be significantly variable in their levels across tested cultivars. Metabolite markers that could be used to distinguish genetically related soybean cultivars were also identified, and metabolite-metabolite correlation analysis revealed some significant associations within the same or among different metabolite groups. Findings from this work may potentially provide the basis for further studies on both soybean seed metabolism and metabolic engineering to improve soybean seed quality and yield.

  5. Changes due to cooking and sterilization in low molecular weight carbohydrates in immature seeds of five cultivars of common bean.

    PubMed

    Słupski, Jacek; Gębczyński, Piotr

    2014-06-01

    Immature seeds of five bean cultivars (flageolet-type and those intended for dry-seed production) were assessed for changes in water-soluble carbohydrates including raffinose family oligosaccharides (RFOs) due to boiling, sterilization, and storage of the sterilized product. About 100 g fresh weight of edible portion of fresh bean seeds contained 2449.3-3182.6 mg total soluble sugars, of which RFOs comprised 44-49%. The highest amounts of these compounds were found in the seeds of the cultivars Laponia and Mona. The dominant oligosaccharide was stachyose. Boiling fresh seeds to consumption consistency reduced total soluble sugars and RFOs: average values were 57% and 55%, respectively. Sterilization in cans resulted in 65% reductions of both total soluble sugars and RFOs. In general, there were no changes in the content of soluble sugars in canned and sterilized products stored for 12 months. PMID:24392956

  6. Changes due to cooking and sterilization in low molecular weight carbohydrates in immature seeds of five cultivars of common bean.

    PubMed

    Słupski, Jacek; Gębczyński, Piotr

    2014-06-01

    Immature seeds of five bean cultivars (flageolet-type and those intended for dry-seed production) were assessed for changes in water-soluble carbohydrates including raffinose family oligosaccharides (RFOs) due to boiling, sterilization, and storage of the sterilized product. About 100 g fresh weight of edible portion of fresh bean seeds contained 2449.3-3182.6 mg total soluble sugars, of which RFOs comprised 44-49%. The highest amounts of these compounds were found in the seeds of the cultivars Laponia and Mona. The dominant oligosaccharide was stachyose. Boiling fresh seeds to consumption consistency reduced total soluble sugars and RFOs: average values were 57% and 55%, respectively. Sterilization in cans resulted in 65% reductions of both total soluble sugars and RFOs. In general, there were no changes in the content of soluble sugars in canned and sterilized products stored for 12 months.

  7. New stable QTLs for berry weight do not colocalize with QTLs for seed traits in cultivated grapevine (Vitis vinifera L.)

    PubMed Central

    2013-01-01

    Background In grapevine, as in other fruit crops, fruit size and seed content are key components of yield and quality; however, very few Quantitative Trait Loci (QTLs) for berry weight and seed content (number, weight, and dry matter percentage) have been discovered so far. To identify new stable QTLs for marker-assisted selection and candidate gene identification, we performed simultaneous QTL detection in four mapping populations (seeded or seedless) with various genetic backgrounds. Results For berry weight, we identified five new QTLs, on linkage groups (LGs) 1, 8, 11, 17 and 18, in addition to the known major QTL on LG 18. The QTL with the largest effect explained up to 31% of total variance and was found in two genetically distant populations on LG 17, where it colocalized with a published putative domestication locus. For seed traits, besides the major QTLs on LG 18 previously reported, we found four new QTLs explaining up to 51% of total variance, on LGs 4, 5, 12 and 14. The previously published QTL for seed number on LG 2 was found related in fact to sex. We found colocalizations between seed and berry weight QTLs only for the major QTL on LG 18 in a seedless background, and on LGs 1 and 13 in a seeded background. Candidate genes belonging to the cell number regulator CNR or cytochrome P450 families were found under the berry weight QTLs on LGs 1, 8, and 17. The involvement of these gene families in fruit weight was first described in tomato using a QTL-cloning approach. Several other interesting candidate genes related to cell wall modifications, water import, auxin and ethylene signalling, transcription control, or organ identity were also found under berry weight QTLs. Conclusion We discovered a total of nine new QTLs for berry weight or seed traits in grapevine, thereby increasing more than twofold the number of reliable QTLs for these traits available for marker assisted selection or candidate gene studies. The lack of colocalization between berry and

  8. Glucose, stem dry weight variation, principal component and cluster analysis for some agronomic traits among 16 regenerated Crotalaria juncea accessions for potential cellulosic ethanol.

    PubMed

    Morris, J Bradley; Antonious, George F

    2013-01-01

    The objectives of this research were to identify candidate sunn hemp accessions having high concentrations of cellulose for use as parents in breeding for cellulose and to determine variability for glucose content and some important agronomic traits among sunn hemp accessions. Since sunn hemp is an under-utilized species, glucose content and agronomic trait variation is essential for the identification of superior sunn hemp accessions for use as potential ethanol for biofuel. Sixteen sunn hemp accessions including the following plant introductions (expressed as glucose concentration) and stem dry weights were studied. "Sixteen sunn hemp accessions including the following plant introductions (expressed as glucose concentration) and stem dry weights were studied." In addition, to verify variability, these traits plus morphological, phenological, and seed reproductive traits were analyzed using multivariate and cluster analysis. The accessions, PI 250487, PI 337080, and PI 219717 produced the highest glucose concentrations (859, 809, and 770 mg g(-1) stem dry weight, respectively), however PI 468956 produced the highest stem dry weight (258 g). Branching significantly correlated with foliage (r(2) = 0.67**) and relative maturity (r(2) = 0.60*), while maturity had a significantly negative correlation with seed number (r(2) = -0.67**) and plant width (r(2) = -0.53*) as well. Seed number significantly correlated with plant width (r(2) = 0.57*). Average linkage cluster analysis grouped the 16 sunn hemp accessions into well-defined phenotypes with four distinct seed-producing groups and one outlier. Based on multivariate and cluster analysis, sufficient variation among these16 sunn hemp accessions exists to support the development of cellulosic ethanol producing cultivars with improved architecture, early maturity, seed yield, glucose concentrations, and stem dry weights. PMID:23356343

  9. Rapid Identification of Candidate Genes for Seed Weight Using the SLAF-Seq Method in Brassica napus.

    PubMed

    Geng, Xinxin; Jiang, Chenghong; Yang, Jie; Wang, Lijun; Wu, Xiaoming; Wei, Wenhui

    2016-01-01

    Seed weight is a critical and direct trait for oilseed crop seed yield. Understanding its genetic mechanism is of great importance for yield improvement in Brassica napus breeding. Two hundred and fifty doubled haploid lines derived by microspore culture were developed from a cross between a large-seed line G-42 and a small-seed line 7-9. According to the 1000-seed weight (TSW) data, the individual DNA of the heaviest 46 lines and the lightest 47 lines were respectively selected to establish two bulked DNA pools. A new high-throughput sequencing technology, Specific Locus Amplified Fragment Sequencing (SLAF-seq), was used to identify candidate genes of TSW in association analysis combined with bulked segregant analysis (BSA). A total of 1,933 high quality polymorphic SLAF markers were developed and 4 associated markers of TSW were procured. A hot region of ~0.58 Mb at nucleotides 25,401,885-25,985,931 on ChrA09 containing 91 candidate genes was identified as tightly associated with the TSW trait. From annotation information, four genes (GSBRNA2T00037136001, GSBRNA2T00037157001, GSBRNA2T00037129001 and GSBRNA2T00069389001) might be interesting candidate genes that are highly related to seed weight.

  10. Rapid Identification of Candidate Genes for Seed Weight Using the SLAF-Seq Method in Brassica napus

    PubMed Central

    Geng, Xinxin; Jiang, Chenghong; Yang, Jie; Wang, Lijun; Wu, Xiaoming; Wei, Wenhui

    2016-01-01

    Seed weight is a critical and direct trait for oilseed crop seed yield. Understanding its genetic mechanism is of great importance for yield improvement in Brassica napus breeding. Two hundred and fifty doubled haploid lines derived by microspore culture were developed from a cross between a large-seed line G-42 and a small-seed line 7–9. According to the 1000-seed weight (TSW) data, the individual DNA of the heaviest 46 lines and the lightest 47 lines were respectively selected to establish two bulked DNA pools. A new high-throughput sequencing technology, Specific Locus Amplified Fragment Sequencing (SLAF-seq), was used to identify candidate genes of TSW in association analysis combined with bulked segregant analysis (BSA). A total of 1,933 high quality polymorphic SLAF markers were developed and 4 associated markers of TSW were procured. A hot region of ~0.58 Mb at nucleotides 25,401,885–25,985,931 on ChrA09 containing 91 candidate genes was identified as tightly associated with the TSW trait. From annotation information, four genes (GSBRNA2T00037136001, GSBRNA2T00037157001, GSBRNA2T00037129001 and GSBRNA2T00069389001) might be interesting candidate genes that are highly related to seed weight. PMID:26824525

  11. Rapid Identification of Candidate Genes for Seed Weight Using the SLAF-Seq Method in Brassica napus.

    PubMed

    Geng, Xinxin; Jiang, Chenghong; Yang, Jie; Wang, Lijun; Wu, Xiaoming; Wei, Wenhui

    2016-01-01

    Seed weight is a critical and direct trait for oilseed crop seed yield. Understanding its genetic mechanism is of great importance for yield improvement in Brassica napus breeding. Two hundred and fifty doubled haploid lines derived by microspore culture were developed from a cross between a large-seed line G-42 and a small-seed line 7-9. According to the 1000-seed weight (TSW) data, the individual DNA of the heaviest 46 lines and the lightest 47 lines were respectively selected to establish two bulked DNA pools. A new high-throughput sequencing technology, Specific Locus Amplified Fragment Sequencing (SLAF-seq), was used to identify candidate genes of TSW in association analysis combined with bulked segregant analysis (BSA). A total of 1,933 high quality polymorphic SLAF markers were developed and 4 associated markers of TSW were procured. A hot region of ~0.58 Mb at nucleotides 25,401,885-25,985,931 on ChrA09 containing 91 candidate genes was identified as tightly associated with the TSW trait. From annotation information, four genes (GSBRNA2T00037136001, GSBRNA2T00037157001, GSBRNA2T00037129001 and GSBRNA2T00069389001) might be interesting candidate genes that are highly related to seed weight. PMID:26824525

  12. Coffee seeds isotopic composition as a potential proxy to evaluate Minas Gerais, Brazil seasonal variations during seed maturation

    NASA Astrophysics Data System (ADS)

    Rodrigues, Carla; Maia, Rodrigo; Brunner, Marion; Carvalho, Eduardo; Prohaska, Thomas; Máguas, Cristina

    2010-05-01

    Plant seeds incorporate the prevailing climate conditions and the physiological response to those conditions (Rodrigues et al., 2009; Rodrigues et al., submitted). During coffee seed maturation the biochemical compounds may either result from accumulated material in other organs such as leafs and/or from new synthesis. Accordingly, plant seeds develop in different stages along a particular part of the year, integrating the plant physiology and seasonal climatic conditions. Coffee bean is an extremely complex matrix, rich in many products derived from both primary and secondary metabolism during bean maturation. Other studies (De Castro and Marraccini, 2006) have revealed the importance of different coffee plant organs during coffee bean development as transfer tissues able to provide compounds (i.e. sugars, organic acids, etc) to the endosperm where several enzymatic activities and expressed genes have been reported. Moreover, it has been proved earlier on that green coffee bean is a particularly suitable case-study (Rodrigues et al., 2009; Rodrigues et al., submitted), not only due to the large southern hemispheric distribution but also because of this product high economic interest. The aim of our work was to evaluate the potential use of green coffee seeds as a proxy to seasonal climatic conditions during coffee bean maturation, through an array of isotopic composition determinations. We have determined carbon, nitrogen, oxygen and sulfur isotopic composition (by IRMS - Isotope Ratio Mass Spectrometry) as well as strontium isotope abundance (by MC-ICP-MS; Multicollector Inductively Coupled Plasma Mass Spectrometry), of green coffee beans harvested at different times at Minas Gerais, Brazil. The isotopic composition data were combined with air temperature and relative humidity data registered during the coffee bean developmental period, and with the parent rock strontium isotopic composition. Results indicate that coffee seeds indeed integrate the interactions

  13. Using soil seed banks to assess temporal patterns of genetic variation in invasive plant populations

    PubMed Central

    Fennell, Mark; Gallagher, Tommy; Vintro, Luis Leon; Osborne, Bruce

    2014-01-01

    Most research on the genetics of invasive plant species has focused on analyzing spatial differences among existing populations. Using a long-established Gunnera tinctoria population from Ireland, we evaluated the potential of using plants derived from seeds associated with different soil layers to track genetic variation through time. This species and site were chosen because (1) G. tinctoria produces a large and persistent seed bank; (2) it has been present in this locality, Sraheens, for ∼90 years; (3) the soil is largely undisturbed; and (4) the soil's age can be reliably determined radiometrically at different depths. Amplified fragment length polymorphic markers (AFLPs) were used to assess differences in the genetic structure of 75 individuals sampled from both the standing population and from four soil layers, which spanned 18 cm (estimated at ∼90 years based on 210Pb and 137Cs dating). While there are difficulties in interpreting such data, including accounting for the effects of selection, seed loss, and seed migration, a clear pattern of lower total allele counts, percentage polymorphic loci, and genetic diversity was observed in deeper soils. The greatest percentage increase in the measured genetic variables occurred prior to the shift from the lag to the exponential range expansion phases and may be of adaptive significance. These findings highlight that seed banks in areas with long-established invasive populations can contain valuable genetic information relating to invasion processes and as such, should not be overlooked. PMID:24967082

  14. Selecting sagebrush seed sources for restoration in a variable climate: ecophysiological variation among genotypes

    USGS Publications Warehouse

    Germino, Matthew J.

    2012-01-01

    Big sagebrush (Artemisia tridentata) communities dominate a large fraction of the United States and provide critical habitat for a number of wildlife species of concern. Loss of big sagebrush due to fire followed by poor restoration success continues to reduce ecological potential of this ecosystem type, particularly in the Great Basin. Choice of appropriate seed sources for restoration efforts is currently unguided due to knowledge gaps on genetic variation and local adaptation as they relate to a changing landscape. We are assessing ecophysiological responses of big sagebrush to climate variation, comparing plants that germinated from ~20 geographically distinct populations of each of the three subspecies of big sagebrush. Seedlings were previously planted into common gardens by US Forest Service collaborators Drs. B. Richardson and N. Shaw, (USFS Rocky Mountain Research Station, Provo, Utah and Boise, Idaho) as part of the Great Basin Native Plant Selection and Increase Project. Seed sources spanned all states in the conterminous Western United States. Germination, establishment, growth and ecophysiological responses are being linked to genomics and foliar palatability. New information is being produced to aid choice of appropriate seed sources by Bureau of Land Management and USFS field offices when they are planning seed acquisitions for emergency post-fire rehabilitation projects while considering climate variability and wildlife needs.

  15. Do key dimensions of seed and seedling functional trait variation capture variation in recruitment probability?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Plant functional traits provide a mechanistic basis for understanding ecological variation among plant species and the implications of this variation for species distribution, community assembly and restoration. 2. The bulk of our functional trait understanding, however, is centered on traits rel...

  16. The influence of mitonuclear genetic variation on personality in seed beetles

    PubMed Central

    Løvlie, Hanne; Immonen, Elina; Gustavsson, Emil; Kazancioğlu, Erem; Arnqvist, Göran

    2014-01-01

    There is a growing awareness of the influence of mitochondrial genetic variation on life-history phenotypes, particularly via epistatic interactions with nuclear genes. Owing to their direct effect on traits such as metabolic and growth rates, mitonuclear interactions may also affect variation in behavioural types or personalities (i.e. behavioural variation that is consistent within individuals, but differs among individuals). However, this possibility is largely unexplored. We used mitonuclear introgression lines, where three mitochondrial genomes were introgressed into three nuclear genetic backgrounds, to disentangle genetic effects on behavioural variation in a seed beetle. We found within-individual consistency in a suite of activity-related behaviours, providing evidence for variation in personality. Composite measures of overall activity of individuals in behavioural assays were influenced by both nuclear genetic variation and by the interaction between nuclear and mitochondrial genomes. More importantly, the degree of expression of behavioural and life-history phenotypes was correlated and mitonuclear genetic variation affected expression of these concerted phenotypes. These results show that mitonuclear genetic variation affects both behavioural and life-history traits, and they provide novel insights into the maintenance of genetic variation in behaviour and personality. PMID:25320161

  17. Fermi energy 5f spectral weight variation in uranium alloys

    SciTech Connect

    Denlinger, J.D.; Clack, J.; Allen, J.W.

    1997-04-01

    Uranium materials display a wide range of thermal, electrical and magnetic properties, often exotic. For more than a decade there have been efforts to use photoemission spectroscopy to develop a systematic and unified understanding of the 5f electron states giving rise to this behavior. These efforts have been hampered by a paucity of systems where changes in transport properties are accompanied by substantial spectral changes, so as to allow an attempt to correlate the two kinds of properties within some model. The authors have made resonant photoemission measurements to extract the 5f spectral weight in three systems which show varying degrees of promise of permitting such an attempt, Y{sub 1{minus}x}U{sub x}Pd{sub 3}, U(Pd{sub x}Pt{sub 1{minus}x}){sub 3} and U(Pd{sub x}Cu{sub 1{minus}x}){sub 5}. They have also measured U 4f core level spectra. The 4f spectra can be modeled with some success by the impurity Anderson model (IAM), and the 5f spectra are currently being analyzed in that framework. The IAM characterizes the 5f-electrons of a single site by an f binding energy {epsilon}{sub f}, an f Coulomb interaction and a hybridization V to conduction electrons. Latent in the model are the phenomena of 5f mixed valence and the Kondo effect.

  18. The atomic weight and isotopic composition of boron and their variation in nature

    SciTech Connect

    Holden, N.E.

    1993-08-01

    The boron isotopic composition and atomic weight value and their variation in nature are reviewed. Questions are raised about the previously recommended value and the uncertainty for the atomic weight. The problem of what constitutes an acceptable range for normal material and what should then be considered geologically exceptional is discussed. Recent measurements make some previous decisions in need of re-evaluation.

  19. Within-litter variation in birth weight: impact of nutritional status in the sow.

    PubMed

    Yuan, Tao-lin; Zhu, Yu-hua; Shi, Meng; Li, Tian-tian; Li, Na; Wu, Guo-yao; Bazer, Fuller W; Zang, Jian-jun; Wang, Feng-lai; Wang, Jun-jun

    2015-06-01

    Accompanying the beneficial improvement in litter size from genetic selection for high-prolificacy sows, within-litter variation in birth weight has increased with detrimental effects on post-natal growth and survival due to an increase in the proportion of piglets with low birth-weight. Causes of within-litter variation in birth weight include breed characteristics that affect uterine space, ovulation rate, degree of maturation of oocytes, duration of time required for ovulation, interval between ovulation and fertilization, uterine capacity for implantation and placentation, size and efficiency of placental transport of nutrients, communication between conceptus/fetus and maternal systems, as well as nutritional status and environmental influences during gestation. Because these factors contribute to within-litter variation in birth weight, nutritional status of the sow to improve fetal-placental development must focus on the following three important stages in the reproductive cycle: pre-mating or weaning to estrus, early gestation and late gestation. The goal is to increase the homogeneity of development of oocytes and conceptuses, decrease variations in conceptus development during implantation and placentation, and improve birth weights of newborn piglets. Though some progress has been made in nutritional regulation of within-litter variation in the birth weight of piglets, additional studies, with a focus on and insights into molecular mechanisms of reproductive physiology from the aspects of maternal growth and offspring development, as well as their regulation by nutrients provided to the sow, are urgently needed.

  20. Within-litter variation in birth weight: impact of nutritional status in the sow*

    PubMed Central

    Yuan, Tao-lin; Zhu, Yu-hua; Shi, Meng; Li, Tian-tian; Li, Na; Wu, Guo-yao; Bazer, Fuller W.; Zang, Jian-jun; Wang, Feng-lai; Wang, Jun-jun

    2015-01-01

    Accompanying the beneficial improvement in litter size from genetic selection for high-prolificacy sows, within-litter variation in birth weight has increased with detrimental effects on post-natal growth and survival due to an increase in the proportion of piglets with low birth-weight. Causes of within-litter variation in birth weight include breed characteristics that affect uterine space, ovulation rate, degree of maturation of oocytes, duration of time required for ovulation, interval between ovulation and fertilization, uterine capacity for implantation and placentation, size and efficiency of placental transport of nutrients, communication between conceptus/fetus and maternal systems, as well as nutritional status and environmental influences during gestation. Because these factors contribute to within-litter variation in birth weight, nutritional status of the sow to improve fetal-placental development must focus on the following three important stages in the reproductive cycle: pre-mating or weaning to estrus, early gestation and late gestation. The goal is to increase the homogeneity of development of oocytes and conceptuses, decrease variations in conceptus development during implantation and placentation, and improve birth weights of newborn piglets. Though some progress has been made in nutritional regulation of within-litter variation in the birth weight of piglets, additional studies, with a focus on and insights into molecular mechanisms of reproductive physiology from the aspects of maternal growth and offspring development, as well as their regulation by nutrients provided to the sow, are urgently needed. PMID:26055904

  1. The Tracking Study: Description of a randomized controlled trial of variations on weight tracking frequency in a behavioral weight loss program

    PubMed Central

    Linde, Jennifer A.; Jeffery, Robert W.; Crow, Scott J.; Brelje, Kerrin L.; Pacanowski, Carly R.; Gavin, Kara L.; Smolenski, Derek J.

    2014-01-01

    Observational evidence from behavioral weight control trials and community studies suggests that greater frequency of weighing oneself, or tracking weight, is associated with better weight outcomes. Conversely, it has also been suggested that frequent weight tracking may have a negative impact on mental health and outcomes during weight loss, but there are minimal experimental data that address this concern in the context of an active weight loss program. To achieve the long-term goal of strengthening behavioral weight loss programs, the purpose of this randomized controlled trial (the Tracking Study) is to test variations on frequency of self-weighing during a behavioral weight loss program, and to examine psychosocial and mental health correlates of weight tracking and weight loss outcomes. Three hundred thirty-nine overweight and obese adults were recruited and randomized to one of three variations on weight tracking frequency during a 12-month weight loss program with a 12-month follow-up: daily weight tracking, weekly weight tracking, or no weight tracking. The primary outcome is weight in kilograms at 24 months. The weight loss program integrates each weight tracking instruction with standard behavioral weight loss techniques (goal setting, self-monitoring, stimulus control, dietary and physical activity enhancements, lifestyle modifications); participants in weight tracking conditions were provided with wireless Internet technology (Wi-Fi-enabled digital scales and touchscreen personal devices) to facilitate weight tracking during the study. This paper describes the study design, intervention features, recruitment, and baseline characteristics of participants enrolled in the Tracking Study. PMID:25533727

  2. Purification and partial characterization of low molecular weight vicilin-like glycoprotein from the seeds of Citrullus lanatus.

    PubMed

    Yadav, Sushila; Tomar, Anil Kumar; Jithesh, O; Khan, Meraj Alam; Yadav, R N; Srinivasan, A; Singh, Tej P; Yadav, Savita

    2011-12-01

    The watermelon (Citrullus lanatus) seeds are highly nutritive and contain large amount of proteins and many beneficial minerals such as magnesium, calcium, potassium, iron, phosphorous, zinc etc. In various parts of the world, C. lanatus seed extracts are used to cure cancer, cardiovascular diseases, hypertension, and blood pressure. C. lanatus seed extracts are also used as home remedy for edema and urinary tract problems. In this study, we isolated protein fraction of C. lanatus seeds using various protein separation methods. We successfully purified a low molecular weight vicilin-like glycoprotein using chromatographic methods followed by SDS-PAGE and MALDI-TOF/MS identification. This is the first report of purification of a vicilin like polypeptide from C. lanatus seeds. In next step, we extracted mRNA from immature seeds and reverse transcribed it using suitable forward and reverse primers for purified glycoprotein. The PCR product was analysed on 1% agarose gel and was subsequently sequenced by Dideoxy DNA sequencing method. An amino acid translation of the gene is in agreement with amino acid sequences of the identified peptides.

  3. Statistical studies on high molecular weight pullulan production in solid state fermentation using jack fruit seed.

    PubMed

    Sugumaran, K R; Sindhu, R V; Sukanya, S; Aiswarya, N; Ponnusami, V

    2013-10-15

    The purpose of the work was to optimize the medium variables for maximizing pullulan production using jack fruit seed as a low cost substrate by Aureobasidium pullulans in solid state fermentation. Effects of K2HPO4, KH2PO4, ZnSO4·5H2O, MgSO4·7H2O, NaCl, (NH4)2SO4·5H2O, yeast extract, moisture content (%, w/w) in the production medium on pullulan production were studied using Plackett-Burman design. Production of pullulan was significantly affected by the medium variables namely KH2PO4, ZnSO4·5H2O, NaCl and moisture content (%, w/w). Then screened variables were optimized by Box Behnken experiment design. The pullulan obtained was characterized and confirmed by FTIR, (1)H NMR and (13)C NMR. Molecular weight of pullulan was found to be 1.733×10(6) g/mol by gel permeation chromatography (GPC).

  4. Rapid development of adaptive, climate-driven clinal variation in seed mass in the invasive annual Forb Echium plantagineum L.

    PubMed

    Konarzewski, Tara K; Murray, Brad R; Godfree, Robert C

    2012-01-01

    We examined adaptive clinal variation in seed mass among populations of an invasive annual species, Echium plantagineum, in response to climatic selection. We collected seeds from 34 field populations from a 1,000 km long temperature and rainfall gradient across the species' introduced range in south-eastern Australia. Seeds were germinated, grown to reproductive age under common glasshouse conditions, and progeny seeds were harvested and weighed. Analyses showed that seed mass was significantly related to climatic factors, with populations sourced from hotter, more arid sites producing heavier seeds than populations from cooler and wetter sites. Seed mass was not related to edaphic factors. We also found that seed mass was significantly related to both longitude and latitude with each degree of longitude west and latitude north increasing seed mass by around 2.5% and 4% on average. There was little evidence that within-population or between-population variation in seed mass varied in a systematic manner across the study region. Our findings provide compelling evidence for development of a strong cline in seed mass across the geographic range of a widespread and highly successful invasive annual forb. Since large seed mass is known to provide reproductive assurance for plants in arid environments, our results support the hypothesis that the fitness and range potential of invasive species can increase as a result of genetic divergence of populations along broad climatic gradients. In E. plantagineum population-level differentiation has occurred in 150 years or less, indicating that the adaptation process can be rapid.

  5. Cryptic Genetic Variation for Arabidopsis thaliana Seed Germination Speed in a Novel Salt Stress Environment

    PubMed Central

    Yuan, Wei; Flowers, Jonathan M.; Sahraie, Dustin J.; Purugganan, Michael D.

    2016-01-01

    The expansion of species ranges frequently necessitates responses to novel environments. In plants, the ability of seeds to disperse to marginal areas relies in part to its ability to germinate under stressful conditions. Here we examine the genetic architecture of Arabidopsis thaliana germination speed under a novel, saline environment, using an Extreme QTL (X-QTL) mapping platform we previously developed. We find that early germination in normal and salt conditions both rely on a QTL on the distal arm of chromosome 4, but we also find unique QTL on chromosomes 1, 2, 4, and 5 that are specific to salt stress environments. Moreover, different QTLs are responsible for early vs. late germination, suggesting a temporal component to the expression of life history under these stress conditions. Our results indicate that cryptic genetic variation exists for responses to a novel abiotic stress, which may suggest a role of such variation in adaptation to new climactic conditions or growth environments. PMID:27543295

  6. Effects of sow nutrition during gestation on within-litter birth weight variation: a review.

    PubMed

    Campos, P H R F; Silva, B A N; Donzele, J L; Oliveira, R F M; Knol, E F

    2012-05-01

    The increasing demand for efficiency in pork production requires great specialization of all sectors involved in this activity. In this context, the development of strategies that could reduce undesirable traits related with negative effects on piglet survival and postnatal growth and development are essential for the pig industry. Currently, special attention is given to variation in birth weight, as some evidences suggest an increased within-litter birth weight variation in modern sows. This variation has been shown to be associated with preweaning mortality, variable weights at weaning and deteriorated growth performance, which results in economic losses and lower efficiency. Therefore, understanding the factors that can influence the events that occur during gestation and that have an impact on the fetal growth and development are important to achieve better efficiency and also to develop strategies that can be used to achieve increased within-litter uniformity of piglet birth weight. This study concludes that even at a given placental size, fetal growth may vary because of differences in placental vascularization and efficiency. Feeding extra feed or energy during late gestation only marginally improves birth weight, and positive effects are not consistent between different studies. The detrimental effects of protein restriction on fetal growth during early gestation may be due to altered placental and endometrial angiogenesis and growth, which leads to a reduction in placental-fetal blood flow, nutrient supply from mother to the fetuses and ultimately to fetal growth retardation. The number of studies that attempted to influence within-litter birth weight variation by means of sow nutrition during gestation is limited. Therefore, more research concerning sow nutrition during gestation associated with the provision of balanced diets to meet requirements of the sows and fetuses are still required. This knowledge may subsequently provide starting points for the

  7. Identification and characterization of high-molecular-weight secalins from triticale seeds by capillary zone electrophoresis.

    PubMed

    Salmanowicz, Boleslaw P

    2010-07-01

    A rapid and reliable method for separation and characterization of the variability of high-molecular-weight secalin subunits (HMW-SS) in hexaploid triticale (x Triticosecale Wittmack) by CZE has been developed. In this method, a mixture of two poly(ethylene oxide) polymers differing in molecular weight and a high concentration of ACN in isoelectric buffer was applied as the running electrolyte. For dynamic coating of the capillary inner wall, a low-concentration mixture of poly(vinylpyrrolidone) and hydroxypropylmethylcellulose was employed. Wide allelic variations in rye HMW-SS composition, including some novel x- and y-type HMW-SS, were detected by CZE. The CZE electropherograms of HMW-SS showed two groups of peaks in accordance with y- and x-type subunits, with migration times of 8.0-8.8 and 11.0-13.3 min, respectively. HMW-SS differed in migration times from the simultaneously resolved HMW glutenin subunits, but frequently had very similar electrophoretic mobilities during separation by SDS-PAGE. Each of the two rye subunits 2r and 6.5r detected by SDS-PAGE represents in fact two subunits (5.1r or 5.2r, and 6.4r or 6.5r, respectively). After analyzing 106 European triticale cultivars, 12 HMW-SS were identified (six x-type and six y-type). They form six allelic variants of these subunits. The simultaneous separation and identification of triticale HMW glutenin and secalin subunits by CZE is an efficient alternative to SDS-PAGE and should facilitate breeding of valuable cultivars.

  8. Evaluation of between- and within-breed variation in measures of weight-age relationships.

    PubMed

    Jenkins, T G; Kaps, M; Cundiff, L V; Ferrell, C L

    1991-08-01

    Variation between- and within-breeds was evaluated for accretion of weight from birth to 7 yr of age and hip height at 7 yr for 1,577 cows sired by Angus, Brahman, Brown Swiss, Charolais, Chianina, Gelbvieh, Hereford, Jersey, Limousin, Maine Anjou, Pinzgauer, Sahiwal, Simmental, South Devon, and Tarentaise and from either Angus or Hereford dams. Parameters from Wt = A (1 - Be-kt) were estimated by nonlinear regressions and provided estimates of mature body weight (A) and rate of weight accretion relative to change in age (k) for each cow. Actual weight at birth, linear adjusted weights at 200, 365, and 500 d of age, ratios of these weights to mature weight, and height at the hip at 7 yr were analyzed. Beyond 20 mo, weights were adjusted to a constant condition score within breed of sire. Variance and covariance components were derived for breed (sigma 2 b), sires within breed (sigma 2 s), and progeny within sire (sigma 2 w). For all traits, the sigma 2 b estimate of genetic variance ranged from two to four times greater than the variance component for sigma 2 s. Between-breed heritabilities were .91 +/- .27 and .54 +/- .17 for A and k, respectively. Estimates of within-breed heritability for these two traits were .61 +/- .11 and .27 +/- .09. Estimates, both between- and within-breed, of the genetic correlation between A and k were moderate to large and negative; those between A and weights at 200, 365, and 500 d and height at maturity were large and positive. Selection for immediate change in measures of growth would be most effective among breeds. Sufficient direct genetic variation exists between breeds to enhance breed improvement of growth characters through breed substitution. Greater opportunity to alter the shape of the growth curve exists through selection for within-breed selection than through breed substitution. PMID:1894547

  9. Trypsin inhibitor from tamarindus indica L. seeds reduces weight gain and food consumption and increases plasmatic cholecystokinin levels

    PubMed Central

    do Nascimento Campos Ribeiro, Joycellane Alline; Serquiz, Alexandre Coellho; dos Santos Silva, Priscila Fabíola; Barbosa, Patrícia Batista Barra Medeiros; Sampaio, Tarcísio Bruno Montenegro; de Araújo, Raimundo Fernandes; de Oliveira, Adeliana Silva; Machado, Richele Janaina Araújo; Maciel, Bruna Leal Lima; Uchôa, Adriana Ferreira; dos Santos, Elizeu Antunes; de Araújo Morais, Ana Heloneida

    2015-01-01

    OBJECTIVES: Seeds are excellent sources of proteinase inhibitors, some of which may have satietogenic and slimming actions. We evaluated the effect of a trypsin inhibitor from Tamarindus indica L. seeds on weight gain, food consumption and cholecystokinin levels in Wistar rats. METHODS: A trypsin inhibitor from Tamarindus was isolated using ammonium sulfate (30–60%) following precipitation with acetone and was further isolated with Trypsin-Sepharose affinity chromatography. Analyses were conducted to assess the in vivo digestibility, food intake, body weight evolution and cholecystokinin levels in Wistar rats. Histological analyses of organs and biochemical analyses of sera were performed. RESULTS: The trypsin inhibitor from Tamarindus reduced food consumption, thereby reducing weight gain. The in vivo true digestibility was not significantly different between the control and Tamarindus trypsin inhibitor-treated groups. The trypsin inhibitor from Tamarindus did not cause alterations in biochemical parameters or liver, stomach, intestine or pancreas histology. Rats treated with the trypsin inhibitor showed significantly elevated cholecystokinin levels compared with animals receiving casein or water. CONCLUSION: The results indicate that the isolated trypsin inhibitor from Tamarindus reduces weight gain by reducing food consumption, an effect that may be mediated by increased cholecystokinin. Thus, the potential use of this trypsin inhibitor in obesity prevention and/or treatment should be evaluated. PMID:25789523

  10. Mathematically combined half-cell reduction potentials of low-molecular-weight thiols as markers of seed ageing.

    PubMed

    Birtić, Simona; Colville, Louise; Pritchard, Hugh W; Pearce, Stephen R; Kranner, Ilse

    2011-09-01

    The half-cell reduction potential of the glutathione disulphide (GSSG)/glutathione (GSH) redox couple appears to correlate with cell viability and has been proposed to be a marker of seed viability and ageing. This study investigated the relationship between seed viability and the individual half-cell reduction potentials (E(i)s) of four low-molecular-weight (LMW) thiols in Lathyrus pratensis seeds subjected to artificial ageing: GSH, cysteine (Cys), cysteinyl-glycine (Cys-Gly) and γ-glutamyl-cysteine (γ-Glu-Cys). The standard redox potential of γ-Glu-Cys was previously unknown and was experimentally determined. The E(i)s were mathematically combined to define a LMW thiol-disulphide based redox environment (E(thiol-disulphide)). Loss of seed viability correlated with a shift in E(thiol-disulphide) towards more positive values, with a LD(50) value of -0.90 ± 0.093 mV M (mean ± SD). The mathematical definition of E(thiol-disulphide) is envisaged as a step towards the definition of the overall cellular redox environment, which will need to include all known redox-couples.

  11. The effect of within-year variation in acorn crop size on seed harvesting by avian hoarders.

    PubMed

    Pesendorfer, Mario B; Koenig, Walter D

    2016-05-01

    Spatial and temporal variation in resource distribution affect the movement and foraging behavior of many animals. In the case of animal-dispersed trees, numerous studies have addressed masting-the synchronized variation in seed production between years-but the fitness consequences of spatial variation in seed production within a year are unclear. We investigated the effects of variable acorn production in a population of valley oaks (Quercus lobata) on the composition and behavior of the avian-disperser community. We found that western scrub-jays (Aphelocoma californica), high-quality dispersers that store seeds in the ground, were attracted to, and exhibited increased per capita dispersal rates from, trees with large acorn crops. In contrast, acorn woodpeckers (Melanerpes formicivorus), low-quality dispersers that store acorns in trees where they are unlikely to germinate, increased per capita hoarding rates but did not attend trees with large seed crops in higher numbers, suggesting that the two species responded to resources on different spatial scales. Antagonistic interactions within and between species increased with the number of birds attending a tree, resulting in a potential cost for foraging birds, but did not reduce dispersal rates. Using a simulation model, we estimated that trees with large initial crops experienced a greater proportion (77 %) of high-quality seed dispersal events than trees with small crops (62 %). Our findings provide support for a mechanistic link between seed production and foraging behavior of seed dispersers as predicted by the predator dispersal hypothesis for the functional consequences of variable seed production in hoarder-dispersed trees.

  12. SEED QUALITY ASSURANCE IN MAIZE BREEDING PROGRAMS: TESTS TO EXPLAIN VARIATIONS IN CORN INBREDS AND POPULATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) breeders are interested in evaluating seed quality of their inbred lines, and seed companies rigorously test the seed quality of the hybrids they produce. Seed quality has a strong relationship to field emergence. There is little information, however, on the influence of the se...

  13. Spatial variations in the associations of term birth weight with ambient air pollution in Georgia, USA.

    PubMed

    Tu, Jun; Tu, Wei; Tedders, Stuart H

    2016-01-01

    Birth weight is an important indicator of overall infant health and a strong predictor of infant morbidity and mortality, and low birth weight (LBW) is a leading cause of infant mortality in the United States. Numerous studies have examined the associations of birth weight with ambient air pollution, but the results were inconsistent. In this study, a spatial statistical technique, geographically weighted regression (GWR) is applied to explore the spatial variations in the associations of birth weight with concentrations of ozone (O3) and fine particulate matter (PM2.5) in the State of Georgia, USA adjusted for gestational age, parity, and six other socioeconomic, behavioral, and land use factors. The results show considerable spatial variations in the associations of birth weight with both pollutants. Significant positive, non-significant, and significant negative relationships between birth weight and concentrations of each air pollutant are all found in different parts of the study area, and the different types of the relationships are affected by the socioeconomic and urban characteristics of the communities where the births are located. The significant negative relationships between birth weight and O3 indicate that O3 is a significant risk factor of LBW and these associations are primarily located in less-urbanized communities. On the other hand, PM2.5 is a significant risk factor of LBW in the more-urbanized communities with higher family income and education attainment. These findings suggest that environmental and health policies should be adjusted to address the different effects of air pollutants on birth outcomes across different types of communities to more effectively and efficiently improve birth outcomes. PMID:27104672

  14. Variation in the terrestrial isotopic composition and atomic weight of argon

    USGS Publications Warehouse

    Böhlke, John Karl

    2014-01-01

    The isotopic composition and atomic weight of argon (Ar) are variable in terrestrial materials. Those variations are a source of uncertainty in the assignment of standard properties for Ar, but they provide useful information in many areas of science. Variations in the stable isotopic composition and atomic weight of Ar are caused by several different processes, including (1) isotope production from other elements by radioactive decay (radiogenic isotopes) or other nuclear transformations (e.g., nucleogenic isotopes), and (2) isotopic fractionation by physical-chemical processes such as diffusion or phase equilibria. Physical-chemical processes cause correlated mass-dependent variations in the Ar isotope-amount ratios (40Ar/36Ar, 38Ar/36Ar), whereas nuclear transformation processes cause non-mass-dependent variations. While atmospheric Ar can serve as an abundant and homogeneous isotopic reference, deviations from the atmospheric isotopic ratios in other Ar occurrences limit the precision with which a standard atomic weight can be given for Ar. Published data indicate variation of Ar atomic weights in normal terrestrial materials between about 39.7931 and 39.9624. The upper bound of this interval is given by the atomic mass of 40Ar, as some samples contain almost pure radiogenic 40Ar. The lower bound is derived from analyses of pitchblende (uranium mineral) containing large amounts of nucleogenic 36Ar and 38Ar. Within this interval, measurements of different isotope ratios (40Ar/36Ar or 38Ar/36Ar) at various levels of precision are widely used for studies in geochronology, water–rock interaction, atmospheric evolution, and other fields.

  15. Genetic variation and seed transfer guidelines for ponderosa pine in the Ochoco and Malheur National Forests of central Oregon. Forest Service research paper

    SciTech Connect

    Sorensen, F.C.; Weber, J.C.

    1994-02-01

    Adaptive genetic variation in seed and seedling traits was evaluated for 280 families from 220 locations. Factor scores from three principal components were related by multiple regression to latitude, longitude, elevation, slope, and aspect of the seed source, and by classification analysis to seed zone and elevation band in seed zone. Location variance was significant but not large. Multiple regression equations explained less than 50 percent of location variance. Slope-aspect variables were important.

  16. Investigations of the Response of Swimming Paramecia to Variations in their Apparent Weight

    NASA Astrophysics Data System (ADS)

    Valles, James; Jung, Ilyong; Guevorkian, Karine; Mickalide, Harry; Wagman, Michael

    2011-11-01

    There is a set of micro-organisms that are small enough that they swim at low Reynolds number and large enough that gravity exerts an influence on their behavior Many protists, like paramecia, for example, exhibit negative gravi-taxis by orienting their swimming upward and negative gravi-kinesis by increasing their propulsion when swimming against their apparent weight. It is not clear whether these responses to a very weak force (about 100 pN) are active or passive. We have developed a technique, Magnetic Force Buoyancy Variation, which enables us to vary the apparent weight of the swimmers in situ. We will describe experiments on paramecia conducted at the National High Magnetic Field Laboratory. In particular, we will describe how increasing the apparent weight induces paramecia to accumulate at upper surfaces. A simple force model suggests that this accumulation is a passive response. Supported by NSF-PHY0750360 and a grant to the NHMFL, NSF DMR-0654118.

  17. Conflicting selection from fire and seed predation drives fine-scaled phenotypic variation in a widespread North American conifer.

    PubMed

    Talluto, Matthew V; Benkman, Craig W

    2014-07-01

    Recent work has demonstrated that evolutionary processes shape ecological dynamics on relatively short timescales (eco-evolutionary dynamics), but demonstrating these effects at large spatial scales in natural landscapes has proven difficult. We used empirical studies and modeling to investigate how selective pressures from fire and predispersal seed predation affect the evolution of serotiny, an ecologically important trait. Serotiny is a highly heritable key reproductive trait in Rocky Mountain lodgepole pine (Pinus contorta subsp. latifolia), a conifer that dominates millions of hectares in western North America. In these forests, the frequency of serotiny determines postfire seedling density with corresponding community- and ecosystem-level effects. We found that serotinous individuals have a selective advantage at high fire frequencies and low predation pressure; however, very high seed predation shifted the selective advantage to nonserotinous individuals even at high fire frequencies. Simulation modeling suggests that spatial variation in the frequency of serotiny results from heterogeneity in these two selective agents. These results, combined with previous findings showing a negative association between the density of seed predators and the frequency of serotiny at both landscape and continental scales, demonstrate that contemporary patterns in serotiny reflect an evolutionary response to conflicting selection pressures from fire and seed predation. Thus, we show that variation in the frequency of a heritable polygenic trait depends on spatial variation in two dominant selective agents, and, importantly, the effects of the local trait variation propagate with profound consequences to the structure and function of communities and ecosystems across a large landscape. PMID:24979772

  18. Conflicting selection from fire and seed predation drives fine-scaled phenotypic variation in a widespread North American conifer

    PubMed Central

    Talluto, Matthew V.; Benkman, Craig W.

    2014-01-01

    Recent work has demonstrated that evolutionary processes shape ecological dynamics on relatively short timescales (eco-evolutionary dynamics), but demonstrating these effects at large spatial scales in natural landscapes has proven difficult. We used empirical studies and modeling to investigate how selective pressures from fire and predispersal seed predation affect the evolution of serotiny, an ecologically important trait. Serotiny is a highly heritable key reproductive trait in Rocky Mountain lodgepole pine (Pinus contorta subsp. latifolia), a conifer that dominates millions of hectares in western North America. In these forests, the frequency of serotiny determines postfire seedling density with corresponding community- and ecosystem-level effects. We found that serotinous individuals have a selective advantage at high fire frequencies and low predation pressure; however, very high seed predation shifted the selective advantage to nonserotinous individuals even at high fire frequencies. Simulation modeling suggests that spatial variation in the frequency of serotiny results from heterogeneity in these two selective agents. These results, combined with previous findings showing a negative association between the density of seed predators and the frequency of serotiny at both landscape and continental scales, demonstrate that contemporary patterns in serotiny reflect an evolutionary response to conflicting selection pressures from fire and seed predation. Thus, we show that variation in the frequency of a heritable polygenic trait depends on spatial variation in two dominant selective agents, and, importantly, the effects of the local trait variation propagate with profound consequences to the structure and function of communities and ecosystems across a large landscape. PMID:24979772

  19. Assessment of genetically modified soybean in relation to natural variation in the soybean seed metabolome.

    PubMed

    Clarke, Joseph D; Alexander, Danny C; Ward, Dennis P; Ryals, John A; Mitchell, Matthew W; Wulff, Jacob E; Guo, Lining

    2013-01-01

    Genetically modified (GM) crops currently constitute a significant and growing part of agriculture.An important aspect of GM crop adoption is to demonstrate safety; identifying differences in end points with respect to conventional crops is a part of the safety assessment process [corrected]. Untargeted metabolomics has the ability to profile diverse classes of metabolites and thus could be an adjunct for identification of differences between the GM crop and its conventional counterpart [corrected].To account for environmental effects and introgression of GM traits into diverse genetic backgrounds, we propose that the assessment for GM crop metabolic composition should be understood within the context of the natural variation for the crop. Using a non-targeted metabolomics platform, we profiled 169 metabolites and established their dynamic ranges from the seeds of 49 conventional soybean lines representing the current commercial genetic diversity. We further demonstrated that the metabolome of a GM line had no significant deviation from natural variation within the soybean metabolome, with the exception of changes in the targeted engineered pathway.

  20. Daily variation in maternal and fetal weight gain in mice and hamsters.

    PubMed

    Davis, F C

    1989-06-01

    Daily variation in maternal and fetal weight gain was measured in hamsters (Mesocricetus auratus) and in mice (Mus musculus, C57Bl) with free access to food or under restricted feeding schedules. Pregnant hamsters with free access to food and water were weighed twice a day and fetuses were collected twice a day from 10.5 to 14.5 days after fertilization. In three experiments, pregnant mice were given free access to food and water or were allowed food for 12 hours a day or for 6 hours a day. Pregnant mice were weighed twice a day and in the restricted feeding experiments, fetuses were collected every 6 hours from 12.0 to 14.5 days after fertilization. Pregnant mice and hamsters with free access to food showed a daily rhythm in weight gain with greater gain at night. There was no evidence of a daily rhythm in the weight gain with greater gain at night. There was no evidence of a daily rhythm in the weight gain of hamster fetuses. Mouse fetuses showed greater weight gain during two 6-hour intervals each day, the second half of each night and the second half of each day. The 12-hour variation was seen in both wet and dry fetal weight. A 24-hour rhythm in fetal growth was previously described in rats (Barr: Teratology, 7:283-288, 1973). Results in rats and mice indicate that fetal growth is modulated on a daily basis. The different periodicity observed in rats and mice might be related to the different ages of the fetuses examined.

  1. Quality trait variations in [⁶⁰Co]-irradiated wheat and high-molecular-weight glutenin subunit mutant identification.

    PubMed

    Lai, D-E; Wang, M; Zhang, C-Y

    2014-10-31

    With 300 Gy of [(60)Co] γ-ray radiation of dry wheat seeds of Vortex 9722, the protein content, wet gluten content, sedimentation value, and hardness variation were analyzed in 341 lines in M4. Using over population mean ± 2X standard deviation as the screening standard, 8 lines with higher protein and wet gluten content and 4 lines with lower protein and wet gluten content were selected. In the M5 generation, the quality traits - silty parameters and high molecular weight glutenin subunits (HMW-GS) - were further analyzed in these 12 lines. The results showed that in the M5 generation, the quality traits in some variants were significantly different from those in the parents; the farinograms varied greatly. Eleven variants had significantly different HMW-GS bands compared to their parents. The parents had a HMW-GS composition of 5 + 14 + 15 + 12 + 9, and the variants had HMW-GS of 11 + 5 + 7 + 9 + 12 subunits or 1 + 5 + 7 + 8 + 12 subunits, indicating that the glutenin loci of these lines were mutated.

  2. Seasonal Variation in the Fate of Seeds under Contrasting Logging Regimes

    PubMed Central

    Fleury, Marina; Rodrigues, Ricardo R.; do Couto, Hilton T. Z.; Galetti, Mauro

    2014-01-01

    Seed predators and dispersers may drive the speed and structure of forest regeneration in natural ecosystems. Rodents and ants prey upon and disperse seeds, yet empirical studies on the magnitude of these effects are lacking. Here, we examined the role of ants and rodents on seed predation in 4 plant species in a successional gradient on a tropical rainforest island. We found that (1) seeds are mostly consumed rather than dispersed; (2) rates of seed predation vary by habitat, season, and species; (3) seed size, shape, and hardness do not affect the probability of being depredated. Rodents were responsible for 70% of seed predation and were negligible (0.14%) seed dispersers, whereas ants were responsible for only 2% of seed predation and for no dispersal. We detected seasonal and habitat effects on seed loss, with higher seed predation occurring during the wet season and in old-growth forests. In the absence of predators regulating seed-consumer populations, the densities of these resilient animals explode to the detriment of natural regeneration and may reduce diversity and carrying capacity for consumers and eventually lead to ecological meltdown. PMID:24614500

  3. Seasonal variation in the fate of seeds under contrasting logging regimes.

    PubMed

    Fleury, Marina; Rodrigues, Ricardo R; do Couto, Hilton T Z; Galetti, Mauro

    2014-01-01

    Seed predators and dispersers may drive the speed and structure of forest regeneration in natural ecosystems. Rodents and ants prey upon and disperse seeds, yet empirical studies on the magnitude of these effects are lacking. Here, we examined the role of ants and rodents on seed predation in 4 plant species in a successional gradient on a tropical rainforest island. We found that (1) seeds are mostly consumed rather than dispersed; (2) rates of seed predation vary by habitat, season, and species; (3) seed size, shape, and hardness do not affect the probability of being depredated. Rodents were responsible for 70% of seed predation and were negligible (0.14%) seed dispersers, whereas ants were responsible for only 2% of seed predation and for no dispersal. We detected seasonal and habitat effects on seed loss, with higher seed predation occurring during the wet season and in old-growth forests. In the absence of predators regulating seed-consumer populations, the densities of these resilient animals explode to the detriment of natural regeneration and may reduce diversity and carrying capacity for consumers and eventually lead to ecological meltdown. PMID:24614500

  4. Switchgrass (Panicum virgatum L.) Intraspecific Variation and Thermotolerance Classification Using in Vitro Seed Germination Assay

    DOE PAGESBeta

    Seepaul, Ramdeo; Macoon, Bisoondat; Reddy, K. Raja; Baldwin, Brian

    2011-01-01

    Cardinal temperatures for plant processes have been used for thermotolerance screening of genotypes, geoclimatic adaptability determination and phenological prediction. Current simulation models for switchgrass (Panicum virgatum L.) utilize single cardinal temperatures across genotypes for both vegetative and reproductive processes although in-tra-specific variation exists among genotypes. An experiment was conducted to estimate the cardinal temperatures for seed germination of 14 diverse switchgrass genotypes and to classify genotypes for temperature tolerance. Stratified seeds of each genotype were germinated at eight constant temperatures from 10 °C to 45 °C under a constant light intensity of 35 μmol m-2s-1 for 12 hd-1. Germination wasmore » recorded at 6-h intervals in all treatments. Maximum seed germination (MSG) and germination rate (GR), estimated by fitting Sigmoidal function to germination-time series data, varied among genotypes. Quadratic and bilinear models best described the MSG and GR responses to temperature, respectively. The mean cardinal temperatures, Tmin, Topt, and Tmax, were 8.1, 26.6, and 45.1 °C for MSG and 11.1, 33.1, and 46.0 °C for GR, respectively. Cardinal temperatures for MSG and GR; however, varied significantly among genotypes. Genotypes were classified as sensitive (Cave-in-Rock, Dacotah, Expresso, Forestburg, Kanlow, Sunburst, Trailblazer, and Tusca), intermediate (Alamo, Blackwell, Carthage, Shawnee, and Shelter) and tolerant (Summer) to high temperature based on cumulative temperature response index (CTRI) estimated by summing individual response indices estimated from the MSG and GR cardinal temperatures. Similarly, genotypes were also classified as sensitive (Alamo, Blackwell, Carthage, Dacotah, Shawnee, Shelter and Summer), moderately sensitive (Cave-in-rock, Forestburg, Kanlow, Sunburst, and Tusca), moderately tolerant (Trailblazer), and tolerant (Expresso) to low temperatures. The cardinal temperature estimates would

  5. Switchgrass (Panicum virgatum L.) Intraspecific Variation and Thermotolerance Classification Using in Vitro Seed Germination Assay

    SciTech Connect

    Seepaul, Ramdeo; Macoon, Bisoondat; Reddy, K. Raja; Baldwin, Brian

    2011-01-01

    Cardinal temperatures for plant processes have been used for thermotolerance screening of genotypes, geoclimatic adaptability determination and phenological prediction. Current simulation models for switchgrass (Panicum virgatum L.) utilize single cardinal temperatures across genotypes for both vegetative and reproductive processes although in-tra-specific variation exists among genotypes. An experiment was conducted to estimate the cardinal temperatures for seed germination of 14 diverse switchgrass genotypes and to classify genotypes for temperature tolerance. Stratified seeds of each genotype were germinated at eight constant temperatures from 10 °C to 45 °C under a constant light intensity of 35 μmol m-2s-1 for 12 hd-1. Germination was recorded at 6-h intervals in all treatments. Maximum seed germination (MSG) and germination rate (GR), estimated by fitting Sigmoidal function to germination-time series data, varied among genotypes. Quadratic and bilinear models best described the MSG and GR responses to temperature, respectively. The mean cardinal temperatures, Tmin, Topt, and Tmax, were 8.1, 26.6, and 45.1 °C for MSG and 11.1, 33.1, and 46.0 °C for GR, respectively. Cardinal temperatures for MSG and GR; however, varied significantly among genotypes. Genotypes were classified as sensitive (Cave-in-Rock, Dacotah, Expresso, Forestburg, Kanlow, Sunburst, Trailblazer, and Tusca), intermediate (Alamo, Blackwell, Carthage, Shawnee, and Shelter) and tolerant (Summer) to high temperature based on cumulative temperature response index (CTRI) estimated by summing individual response indices estimated from the MSG and GR cardinal temperatures. Similarly, genotypes were also classified as sensitive (Alamo, Blackwell, Carthage, Dacotah, Shawnee, Shelter and Summer), moderately sensitive (Cave-in-rock, Forestburg, Kanlow, Sunburst, and Tusca), moderately tolerant (Trailblazer), and tolerant (Expresso) to

  6. Genome-Wide Association Study of Arabidopsis thaliana Identifies Determinants of Natural Variation in Seed Oil Composition.

    PubMed

    Branham, Sandra E; Wright, Sara J; Reba, Aaron; Linder, C Randal

    2016-05-01

    The renewable source of highly reduced carbon provided by plant triacylglycerols (TAGs) fills an ever increasing demand for food, biodiesel, and industrial chemicals. Each of these uses requires different compositions of fatty acid proportions in seed oils. Identifying the genes responsible for variation in seed oil composition in nature provides targets for bioengineering fatty acid proportions optimized for various industrial and nutrition goals. Here, we characterized the seed oil composition of 391 world-wide, wild accessions of Arabidopsis thaliana, and performed a genome-wide association study (GWAS) of the 9 major fatty acids in the seed oil and 4 composite measures of the fatty acids. Four to 19 regions of interest were associated with the seed oil composition traits. Thirty-four of the genes in these regions are involved in lipid metabolism or transport, with 14 specific to fatty acid synthesis or breakdown. Eight of the genes encode transcription factors. We have identified genes significantly associated with variation in fatty acid proportions that can be used as a resource across the Brassicaceae. Two-thirds of the regions identified contain candidate genes that have never been implicated in lipid metabolism and represent potential new targets for bioengineering.

  7. Genome-Wide Association Study of Arabidopsis thaliana Identifies Determinants of Natural Variation in Seed Oil Composition.

    PubMed

    Branham, Sandra E; Wright, Sara J; Reba, Aaron; Linder, C Randal

    2016-05-01

    The renewable source of highly reduced carbon provided by plant triacylglycerols (TAGs) fills an ever increasing demand for food, biodiesel, and industrial chemicals. Each of these uses requires different compositions of fatty acid proportions in seed oils. Identifying the genes responsible for variation in seed oil composition in nature provides targets for bioengineering fatty acid proportions optimized for various industrial and nutrition goals. Here, we characterized the seed oil composition of 391 world-wide, wild accessions of Arabidopsis thaliana, and performed a genome-wide association study (GWAS) of the 9 major fatty acids in the seed oil and 4 composite measures of the fatty acids. Four to 19 regions of interest were associated with the seed oil composition traits. Thirty-four of the genes in these regions are involved in lipid metabolism or transport, with 14 specific to fatty acid synthesis or breakdown. Eight of the genes encode transcription factors. We have identified genes significantly associated with variation in fatty acid proportions that can be used as a resource across the Brassicaceae. Two-thirds of the regions identified contain candidate genes that have never been implicated in lipid metabolism and represent potential new targets for bioengineering. PMID:26704140

  8. Integration of Experiments across Diverse Environments Identifies the Genetic Determinants of Variation in Sorghum bicolor Seed Element Composition1[OPEN

    PubMed Central

    Connolly, Erin L.

    2016-01-01

    Seedling establishment and seed nutritional quality require the sequestration of sufficient element nutrients. The identification of genes and alleles that modify element content in the grains of cereals, including sorghum (Sorghum bicolor), is fundamental to developing breeding and selection methods aimed at increasing bioavailable element content and improving crop growth. We have developed a high-throughput work flow for the simultaneous measurement of multiple elements in sorghum seeds. We measured seed element levels in the genotyped Sorghum Association Panel, representing all major cultivated sorghum races from diverse geographic and climatic regions, and mapped alleles contributing to seed element variation across three environments by genome-wide association. We observed significant phenotypic and genetic correlation between several elements across multiple years and diverse environments. The power of combining high-precision measurements with genome-wide association was demonstrated by implementing rank transformation and a multilocus mixed model to map alleles controlling 20 element traits, identifying 255 loci affecting the sorghum seed ionome. Sequence similarity to genes characterized in previous studies identified likely causative genes for the accumulation of zinc, manganese, nickel, calcium, and cadmium in sorghum seeds. In addition to strong candidates for these five elements, we provide a list of candidate loci for several other elements. Our approach enabled the identification of single-nucleotide polymorphisms in strong linkage disequilibrium with causative polymorphisms that can be evaluated in targeted selection strategies for plant breeding and improvement. PMID:26896393

  9. Healthy food trends -- chia seeds

    MedlinePlus

    ... Healthy food trends - salvia; Healthy snacks - Chia seeds; Weight loss - Chia seeds; Healthy diet - Chia seeds; Wellness - Chia ... fiber. Some think chia seeds may help with weight loss and other risk factors, but this has not ...

  10. Natural variation of fecundity components in a widespread plant with dimorphic seeds

    NASA Astrophysics Data System (ADS)

    Braza, Rita; Arroyo, J.; García, M. B.

    2010-09-01

    The number and size of seeds are the basis of the quantity and quality components of female reproductive fitness in plants, playing a central role in the evolutionary ecology of life history diversification. In this study we show and analyze the natural variability of several fecundity variables (fruit set, seed production per fruit, seed size, total seed production per plant, and proportion of small seeds) in Plantago coronopus, a widespread, short-lived herb with dimorphic seeds. The structure of such variability was examined at the individual, population (eight locations with different environments within the same region), and life history levels (annual vs perennial), and correlated to soil fertility. There was no divergence associated to the life history for any of the variables studied. Total seed production (the quantity component of female fitness) was correlated with maternal resources, while the size of the large mucilaginous, basal seeds, and the proportion of the small apical seeds (quality component) were more associated to environmental resources. Thus, internal and external resources shape different fitness components, maximizing seed production, and fitting the size and proportion of different kind of seeds to local conditions irrespective of life history. P. coronopus illustrates the versatility of short-lived widespread plants to combine fecundity traits in a flexible manner, in order to increase fitness at each of the many possible habitats they occupy over heterogeneous environments.

  11. [Seasonal variations of wild apricot seed dispersal and hoarding by rodents in rehabilitated land].

    PubMed

    Ma, Qing-liang; Zhao, Xue-feng; Sun, Ming-yang; Lu, Ji-qi; Kong, Mao-cai

    2010-05-01

    Rodents feed with and disperse plant seeds, which may thereby affect the seed spatiotemporal distribution, germination, and seedling establishment, and eventually play an important role in the restoration of deforested area. Taking the State-owned Yugong Forest Farm in Jiyuan of Henan, China as study site, the tagged seeds of wild apricot (Prunus armeniaca) were artificially released in rehabilitated land in the spring, summer, and autumn 2008, aimed to investigate their dispersal and hoarding by rodents in different seasons. It was found that Apodemus peninsulae, Niviventer confucianus, and Apodemus agrarius were the main rodent species acting on the seed dispersal and hoarding. The dispersal rate of the seeds was significantly lower in spring than in summer, and also, lower in summer than in autumn. The amount of removed seeds was affected by the interaction of season and seed status, being significantly lesser in spring than in summer, and lesser in summer than in autumn. The mean transportation distance differed with seasons, which was longer in autumn than in spring and summer. The cache size in majority caches was 1 seed, but in a few caches, each cache contained 2 or 3 seeds. The cache number was affected by the interaction of season and seed status, i.e., one seed cache was lesser in spring than in summer and autumn, while the caches containing 2 or 3 seeds were more in summer and autumn. Among the 1800 seeds released, there were five seeds hoarded in summer and autumn respectively established seedlings in the next year of the experiment.

  12. Intraspecific variation in seed dispersal of a Neotropical tree and its relationship to fruit and tree traits.

    PubMed

    Augspurger, Carol K; Franson, Susan E; Cushman, Katherine C; Muller-Landau, Helene C

    2016-02-01

    The distribution of wind-dispersed seeds around a parent tree depends on diaspore and tree traits, as well as wind conditions and surrounding vegetation. This study of a neotropical canopy tree, Platypodium elegans, explored the extent to which parental variation in diaspore and tree traits explained (1) rate of diaspore descent in still air, (2) distributions of diaspores dispersed from a 40-m tower in the forest, and (3) natural diaspore distributions around the parent tree. The geometric mean rate of descent in still air among 20 parents was highly correlated with geometric mean wing loading(1/2) (r = 0.84). However, diaspore traits and rate of descent predicted less variation in dispersal distance from the tower, although descent rate(-1) consistently correlated with dispersal distance. Measured seed shadows, particularly their distribution edges, differed significantly among six parents (DBH range 62-181 cm) and were best fit by six separate anisotropic dispersal kernels and surveyed fecundities. Measured rate of descent and tree traits, combined in a mechanistic seed dispersal model, did not significantly explain variation among parents in natural seed dispersal distances, perhaps due to the limited power to detect effects with only six trees. Seedling and sapling distributions were at a greater mean distance from the parents than seed distributions; saplings were heavily concentrated at far distances. Variation among parents in the distribution tails so critical for recruitment could not be explained by measured diaspore or tree traits with this sample size, and may be determined more by wind patterns and the timing of abscission in relation to wind conditions. Studies of wind dispersal need to devote greater field efforts at recording the "rare" dispersal events that contribute to far dispersal distances, following their consequences, and in understanding the mechanisms that generate them. PMID:26839686

  13. Intraspecific variation in seed dispersal of a Neotropical tree and its relationship to fruit and tree traits.

    PubMed

    Augspurger, Carol K; Franson, Susan E; Cushman, Katherine C; Muller-Landau, Helene C

    2016-02-01

    The distribution of wind-dispersed seeds around a parent tree depends on diaspore and tree traits, as well as wind conditions and surrounding vegetation. This study of a neotropical canopy tree, Platypodium elegans, explored the extent to which parental variation in diaspore and tree traits explained (1) rate of diaspore descent in still air, (2) distributions of diaspores dispersed from a 40-m tower in the forest, and (3) natural diaspore distributions around the parent tree. The geometric mean rate of descent in still air among 20 parents was highly correlated with geometric mean wing loading(1/2) (r = 0.84). However, diaspore traits and rate of descent predicted less variation in dispersal distance from the tower, although descent rate(-1) consistently correlated with dispersal distance. Measured seed shadows, particularly their distribution edges, differed significantly among six parents (DBH range 62-181 cm) and were best fit by six separate anisotropic dispersal kernels and surveyed fecundities. Measured rate of descent and tree traits, combined in a mechanistic seed dispersal model, did not significantly explain variation among parents in natural seed dispersal distances, perhaps due to the limited power to detect effects with only six trees. Seedling and sapling distributions were at a greater mean distance from the parents than seed distributions; saplings were heavily concentrated at far distances. Variation among parents in the distribution tails so critical for recruitment could not be explained by measured diaspore or tree traits with this sample size, and may be determined more by wind patterns and the timing of abscission in relation to wind conditions. Studies of wind dispersal need to devote greater field efforts at recording the "rare" dispersal events that contribute to far dispersal distances, following their consequences, and in understanding the mechanisms that generate them.

  14. Variations and controlling factors of the coccolith weight in the Western Pacific Warm Pool over the last 200 ka

    NASA Astrophysics Data System (ADS)

    Liang, Dan; Liu, Chuanlian

    2016-06-01

    Using a coccolith weight analytic software (Particle Analyser), we analyze most abundant coccolith species in a sediment core from the central Western Pacific Warm Pool (WPWP) and calculate coccolith size and weight variations over the last 200 ka. These variations are compared with the trends of sea surface temperature (SST), primary productivity (PP), sea surface salinity (SSS), and insolation. Our results demonstrate that the size and weight of the coccoliths varied in response to variations of these factors, and their average total weight is primarily related to the relative abundance of the dominant species GEO ( Gephyrocapsa oceanica). The variation in weight of EMI ( Emiliania huxleyi) and GEE ( Gephyrocapsa ericsonii) are mainly influenced by nutrients, and the variation of GEM ( G. muellerae conformis) and GEO ( G. oceanica) weight are mainly influenced by SST. For all of the taxa weight, PP and SST present apparent precession or semi-precession cycles, we consider that the mono-coccolith weight of the Equatorial Western Pacific is primarily affected by precession drived thermocline and nutricline variation.

  15. Geographic variation in the flood-induced fluctuating temperature requirement for germination in Setaria parviflora seeds.

    PubMed

    Mollard, F P O; Insausti, P

    2011-07-01

    Our aim was to search for specific seed germinative strategies related to flooding escape in Setaria parviflora, a common species across the Americas. For this purpose, we investigated induction after floods, in relation to fluctuating temperature requirements for germination in seeds from mountain, floodplain and successional grasslands. A laboratory experiment was conducted in which seeds were imbibed or immersed in water at 5°C. Seeds were also buried in flood-prone and upland grasslands and exhumed during the flooding season. Additionally, seeds were buried in flooded or drained grassland mesocosms. Germination of exhumed seeds was assayed at 25°C or at 20°C/30°C in the dark or in the presence of red light pulses. After submergence or soil flooding, a high fraction (>32%) of seeds from the floodplain required fluctuating temperatures to germinate. In contrast, seeds from the mountains showed maximum differences in germination between fluctuating and constant temperature treatment only after imbibition (35%) or in non-flooded soil conditions (40%). The fluctuating temperature requirement was not clearly related to the foregoing conditions in the successional grassland seeds. Maximum germination could also be attained with red light pulses to seeds from mountain and successional grasslands. Results show that the fluctuating temperature requirement might help floodplain seeds to germinate after floods, indicating a unique feature of the dormancy of S. parviflora seeds from floodplains, which suggests an adaptive advantage aimed at postponing emergence during inundation periods. In contrast, the fluctuating temperature required for germination among seeds from mountain and successional grasslands show its importance for gap detection. PMID:21668607

  16. Interspecific variation in persistence of buried weed seeds follows trade-offs among physiological, chemical and physical seed defences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil seedbanks drive infestations of annual weeds, yet weed management focuses largely on seedling mortality. As weed seedbanks increasingly become reservoirs of herbicide resistance, species-specific seedbank management approaches will be essential. Limited understanding of interspecific variation ...

  17. Toxicity of anthraquinones: differential effects of rumex seed extracts on rat organ weights and biochemical and haematological parameters.

    PubMed

    Islam, Rabigul; Mamat, Yultuz; Ismayil, Ilyar; Yan, Ming; Kadir, Mahsutjan; Abdugheny, Abdujilil; Rapkat, Haximjan; Niyaz, Mardan; Ali, Yusupjan; Abay, Sirapil

    2015-05-01

    The genus Rumex and related species such as Rheum and Polygonum are widely used as medicinal herbs and foods. They contain anthraquinones (AQ) such as emodin and chrysophanol as active ingredients, and there is concern about the toxicity of these compounds. This study evaluated the chronic effects of Rumex patientia seed aqueous and ethanolic extracts, in male and female rats separately, on organ weights and over 30 haematological, biochemical and histological parameters, immediately after 14-week administration and after a further period of 15 days without drug treatment. Adverse changes were associated with long-term AQ administration, and these focussed on the liver, lung and kidney, but after 15-day convalescence, most had reverted to normal. In general, male rats appeared to be more susceptible than female rats at similar doses. The water extract produced no irreversible changes, which may reflect the lower dose of the AQ constituents or the presence of different ancillary compounds, and supports the traditional method of extracting Rumex seeds with water. In conclusion, ethanolic extracts of R. patientia caused irreversible pathological changes at very high doses (4000mg/kg), but lower doses and aqueous extracts produced either non-significant or reversible changes. Long-term administration of high doses of AQ extracts over a long period of time should be avoided until further assurances can be given, and given other existing reports of reproductive toxicity, should be avoided altogether during pregnancy.

  18. Genome-wide conserved non-coding microsatellite (CNMS) marker-based integrative genetical genomics for quantitative dissection of seed weight in chickpea.

    PubMed

    Bajaj, Deepak; Saxena, Maneesha S; Kujur, Alice; Das, Shouvik; Badoni, Saurabh; Tripathi, Shailesh; Upadhyaya, Hari D; Gowda, C L L; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K; Parida, Swarup K

    2015-03-01

    Phylogenetic footprinting identified 666 genome-wide paralogous and orthologous CNMS (conserved non-coding microsatellite) markers from 5'-untranslated and regulatory regions (URRs) of 603 protein-coding chickpea genes. The (CT)n and (GA)n CNMS carrying CTRMCAMV35S and GAGA8BKN3 regulatory elements, respectively, are abundant in the chickpea genome. The mapped genic CNMS markers with robust amplification efficiencies (94.7%) detected higher intraspecific polymorphic potential (37.6%) among genotypes, implying their immense utility in chickpea breeding and genetic analyses. Seventeen differentially expressed CNMS marker-associated genes showing strong preferential and seed tissue/developmental stage-specific expression in contrasting genotypes were selected to narrow down the gene targets underlying seed weight quantitative trait loci (QTLs)/eQTLs (expression QTLs) through integrative genetical genomics. The integration of transcript profiling with seed weight QTL/eQTL mapping, molecular haplotyping, and association analyses identified potential molecular tags (GAGA8BKN3 and RAV1AAT regulatory elements and alleles/haplotypes) in the LOB-domain-containing protein- and KANADI protein-encoding transcription factor genes controlling the cis-regulated expression for seed weight in the chickpea. This emphasizes the potential of CNMS marker-based integrative genetical genomics for the quantitative genetic dissection of complex seed weight in chickpea.

  19. Stochastic variation in food availability influences weight and age at maturity.

    PubMed

    Tenhumberg, B; Tyre, A J; Roitberg, B

    2000-02-21

    Variation in mean food availability, and in the variance around the mean, affects the growth rate during development. Previous theoretical work on the influence of environmental quality or growth rates on the phenotypic traits age and size at maturation assumed that there is no variation in growth rate or food availability within a generation. We develop a stochastic dynamic programming (SDP) model of the foraging behaviour of aphidophagous syrphids, and use this model to predict when syrphids should pupate (mature) when average food availability changes, or varies stochastically, during development. The optimal strategy takes into account not only the availability of food, but also the timing of its availability. Food availability, when small, influences developmental time, but not weight at pupation. Food availability, when large, influences weight at pupation, but not developmental time. When the food supply is low, the optimal strategy adjusts the size at pupation downwards for stochastic as opposed to deterministic availability of food. The conclusions reinforce the need for life-history studies to consider state dependence and short-term variability in growth rates. PMID:10666359

  20. A reexamination of age-related variation in body weight and morphometry of Maryland nutria

    USGS Publications Warehouse

    Sherfy, M.H.; Mollett, T.A.; McGowan, K.R.; Daugherty, S.L.

    2006-01-01

    Age-related variation in morphometry has been documented for many species. Knowledge of growth patterns can be useful for modeling energetics, detecting physiological influences on populations, and predicting age. These benefits have shown value in understanding population dynamics of invasive species, particularly in developing efficient control and eradication programs. However, development and evaluation of descriptive and predictive models is a critical initial step in this process. Accordingly, we used data from necropsies of 1,544 nutria (Myocastor coypus) collected in Maryland, USA, to evaluate the accuracy of previously published models for prediction of nutria age from body weight. Published models underestimated body weights of our animals, especially for ages <3. We used cross-validation procedures to develop and evaluate models for describing nutria growth patterns and for predicting nutria age. We derived models from a randomly selected model-building data set (n = 192-193 M, 217-222 F) and evaluated them with the remaining animals (n = 487-488 M, 642-647 F). We used nonlinear regression to develop Gompertz growth-curve models relating morphometric variables to age. Predicted values of morphometric variables fell within the 95% confidence limits of their true values for most age classes. We also developed predictive models for estimating nutria age from morphometry, using linear regression of log-transformed age on morphometric variables. The evaluation data set corresponded with 95% prediction intervals from the new models. Predictive models for body weight and length provided greater accuracy and less bias than models for foot length and axillary girth. Our growth models accurately described age-related variation in nutria morphometry, and our predictive models provided accurate estimates of ages from morphometry that will be useful for live-captured individuals. Our models offer better accuracy and precision than previously published models

  1. Supplementation of cottonseed, linseed, and noug seed cakes on feed intake, digestibility, body weight, and carcass parameters of Sidama goats.

    PubMed

    Alemu, Wondwosen; Melaku, Solomon; Tolera, Adugna

    2010-04-01

    A digestibility, feed intake, and carcass evaluation experiment using 20 yearling intact male Sidama goats weighing 16.4 +/- 0.63 kg (mean +/- SD) was conducted in Ethiopia with the objectives to determine feed intake, digestibility, body weight (BW) gain, and carcass parameters. The treatments included feeding natural pasture hay (T1, control) and supplementation with cottonseed cake (284 g-T2), linseed cake (250 g-T3), and noug seed cake (296 g-T4) on dry matter (DM) basis to supply 85 g crude protein (CP) per head per day. Randomized complete block design for feed intake and BW parameters and complete randomized design for digestibility and carcass parameters were used. Hay DM intake was higher (P < 0.01) for T1 than for the other treatments. T3 promoted higher (P < 0.01) DM (29.3 g/kg W(0.75)/day) and CP (14.1 g/kg W(0.75)/day) intake than T4 (8.9 g/kg W(0.75)/day DM and 4.1 g/kg W(0.75)/day CP). T3 showed better (P < 0.05) organic matter and CP digestibility than T2. Goats in T3 had higher nitrogen intake (P < 0.01) and retention (P < 0.05) than those in T1. Goats in T2 and T3 showed higher (P < 0.05) daily BW gain and final BW than those in T4 and T1. Goats in T2 and T3 had higher (P < 0.05) slaughter weight, empty BW, hot carcass weight, rib-eye muscle area, and dressing percentage on slaughter weight basis than those in T1. The results showed that T2 and T3 had similar effect on CP intake, daily BW gain, and carcass parameters for growing Sidama goats fed natural pasture hay.

  2. Co-variation between seed dormancy, growth rate and flowering time changes with latitude in Arabidopsis thaliana.

    PubMed

    Debieu, Marilyne; Tang, Chunlao; Stich, Benjamin; Sikosek, Tobias; Effgen, Sigi; Josephs, Emily; Schmitt, Johanna; Nordborg, Magnus; Koornneef, Maarten; de Meaux, Juliette

    2013-01-01

    Life-history traits controlling the duration and timing of developmental phases in the life cycle jointly determine fitness. Therefore, life-history traits studied in isolation provide an incomplete view on the relevance of life-cycle variation for adaptation. In this study, we examine genetic variation in traits covering the major life history events of the annual species Arabidopsis thaliana: seed dormancy, vegetative growth rate and flowering time. In a sample of 112 genotypes collected throughout the European range of the species, both seed dormancy and flowering time follow a latitudinal gradient independent of the major population structure gradient. This finding confirms previous studies reporting the adaptive evolution of these two traits. Here, however, we further analyze patterns of co-variation among traits. We observe that co-variation between primary dormancy, vegetative growth rate and flowering time also follows a latitudinal cline. At higher latitudes, vegetative growth rate is positively correlated with primary dormancy and negatively with flowering time. In the South, this trend disappears. Patterns of trait co-variation change, presumably because major environmental gradients shift with latitude. This pattern appears unrelated to population structure, suggesting that changes in the coordinated evolution of major life history traits is adaptive. Our data suggest that A. thaliana provides a good model for the evolution of trade-offs and their genetic basis. PMID:23717385

  3. Interspecific and annual variation in pre-dispersal seed predation by a granivorous bird in two East Asian hackberries, Celtis biondii and Celtis sinensis.

    PubMed

    Yoshikawa, T; Masaki, T; Isagi, Y; Kikuzawa, K

    2012-05-01

    Pre-dispersal seed predation by granivorous birds has potential to limit fruit removal and subsequent seed dispersal by legitimate avian seed dispersers in bird-dispersed plants, especially when the birds form flocks. We monitored pre-dispersal seed predation by the Japanese grosbeak, Eophona personata, of two bird-dispersed hackberry species (Cannabaceae), Celtis biondii (four trees) and Celtis sinensis (10 trees), for 3 years (2005, 2007 and 2008) in a fragmented forest in temperate Japan. Throughout the 3 years, predation was more intense on C. biondii, which, as a consequence, lost a larger part of its fruit crop. Grosbeaks preferred C. biondii seeds that had a comparatively lower energy content and lower hardness than C. sinensis, suggesting an association between seed hardness and selective foraging by grosbeaks. In C. biondii, intensive predation markedly reduced fruit duration and strongly limited fruit removal by seed dispersers, especially in 2007 and 2008. In C. sinensis, seed dispersers consumed fruits throughout the fruiting seasons in all 3 years. In C. biondii, variation in the timing of grosbeak migration among years was associated with annual variation in this bird's effects on fruit removal. Our results demonstrate that seed predation by flocks of granivorous birds can dramatically disrupt seed dispersal in fleshy-fruited plants and suggest the importance of understanding their flocking behaviour. PMID:22136589

  4. Evapotranspiration partitioning and variation of sap flow in female and male parents of maize for hybrid seed production in arid region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the variation of sap flow in female and male parents of maize for hybrid seed production and evapotranspiration (ET) partitioning is useful in accurately determining water use of the female and male parents and improving irrigation management of maize for hybrid seed production. Sap fl...

  5. Functional variation among frugivorous birds: implications for rainforest seed dispersal in a fragmented subtropical landscape.

    PubMed

    Moran, C; Catterall, C P; Green, R J; Olsen, M F

    2004-12-01

    Seed dispersal plays a critical role in rainforest regeneration patterns, hence loss of avian seed dispersers in fragmented landscapes may disrupt forest regeneration dynamics. To predict whether or not a plant will be dispersed in fragmented forests, it is necessary to have information about frugivorous bird distribution and dietary composition. However, specific dietary information for frugivorous birds is often limited. In such cases, information on the seed-crushing behaviour, gape width and relative dietary dominance by fruit may be used to describe functional groups of bird species with respect to their potential to disperse similar seeds. We used this information to assess differences in the seed dispersal potential of frugivorous bird assemblages in a fragmented rainforest landscape of southeast Queensland, Australia. The relative abundance of frugivorous birds was surveyed in extensive, remnant and regrowth rainforest sites (16 replicates of each). Large-gaped birds with mixed diets and medium-gaped birds with fruit-dominated diets were usually less abundant in remnants and regrowth than in continuous forest. Small-gaped birds with mixed diets and birds with fruit as a minor dietary component were most abundant in regrowth. We recorded a similar number of seed-crushing birds and large-gaped birds with fruit-dominated diets across site types. Bird species that may have the greatest potential to disperse a large volume and wide variety of plants, including large-seeded plants, tended to be less abundant outside of extensive forests, although one species, the figbird Sphecotheres viridis, was much more abundant in these areas. The results suggest that the dispersal of certain plant taxa would be limited in this fragmented landscape, although the potential for the dispersal of large-seeded plants may remain, despite the loss of several large-gaped disperser species.

  6. Total variation-regularized weighted nuclear norm minimization for hyperspectral image mixed denoising

    NASA Astrophysics Data System (ADS)

    Wu, Zhaojun; Wang, Qiang; Wu, Zhenghua; Shen, Yi

    2016-01-01

    Many nuclear norm minimization (NNM)-based methods have been proposed for hyperspectral image (HSI) mixed denoising due to the low-rank (LR) characteristics of clean HSI. However, the NNM-based methods regularize each eigenvalue equally, which is unsuitable for the denoising problem, where each eigenvalue stands for special physical meaning and should be regularized differently. However, the NNM-based methods only exploit the high spectral correlation, while ignoring the local structure of HSI and resulting in spatial distortions. To address these problems, a total variation (TV)-regularized weighted nuclear norm minimization (TWNNM) method is proposed. To obtain the desired denoising performance, two issues are included. First, to exploit the high spectral correlation, the HSI is restricted to be LR, and different eigenvalues are minimized with different weights based on the WNNM. Second, to preserve the local structure of HSI, the TV regularization is incorporated, and the alternating direction method of multipliers is used to solve the resulting optimization problem. Both simulated and real data experiments demonstrate that the proposed TWNNM approach produces superior denoising results for the mixed noise case in comparison with several state-of-the-art denoising methods.

  7. Robust dynamic myocardial perfusion CT deconvolution using adaptive-weighted tensor total variation regularization

    NASA Astrophysics Data System (ADS)

    Gong, Changfei; Zeng, Dong; Bian, Zhaoying; Huang, Jing; Zhang, Xinyu; Zhang, Hua; Lu, Lijun; Feng, Qianjin; Liang, Zhengrong; Ma, Jianhua

    2016-03-01

    Dynamic myocardial perfusion computed tomography (MPCT) is a promising technique for diagnosis and risk stratification of coronary artery disease by assessing the myocardial perfusion hemodynamic maps (MPHM). Meanwhile, the repeated scanning of the same region results in a relatively large radiation dose to patients potentially. In this work, we present a robust MPCT deconvolution algorithm with adaptive-weighted tensor total variation regularization to estimate residue function accurately under the low-dose context, which is termed `MPD-AwTTV'. More specifically, the AwTTV regularization takes into account the anisotropic edge property of the MPCT images compared with the conventional total variation (TV) regularization, which can mitigate the drawbacks of TV regularization. Subsequently, an effective iterative algorithm was adopted to minimize the associative objective function. Experimental results on a modified XCAT phantom demonstrated that the present MPD-AwTTV algorithm outperforms and is superior to other existing deconvolution algorithms in terms of noise-induced artifacts suppression, edge details preservation and accurate MPHM estimation.

  8. Genetic variation of the weaning weight of beef cattle as a function of accumulated heat stress.

    PubMed

    Santana, M L; Bignardi, A B; Eler, J P; Ferraz, J B S

    2016-04-01

    The objective of this study was to identify the genetic variation in the weaning weight (WW) of beef cattle as a function of heat stress. The WWs were recorded at approximately 205 days of age in three Brazilian beef cattle populations: Nelore (93,616), Brangus (18,906) and Tropical Composite (62,679). In view of the cumulative nature of WW, the effect of heat stress was considered as the accumulation of temperature and humidity index units (ACTHI) from the animal's birth to weaning. A reaction norm model was used to estimate the (co)variance components of WW across the ACTHI scale. The accumulation of THI units from birth to weaning negatively affected the WW. The definition of accumulated THI units as an environmental descriptor permitted to identify important genetic variation in the WW as a function of heat stress. As evidence of genotype by environment interaction, substantial heterogeneity was observed in the (co)variance components for WW across the environmental gradient. In this respect, the best animals in less stressful environments are not necessarily the best animals in more stressful environments. Furthermore, the response to selection for WW is expected to be lower in more stressful environments.

  9. Genetic variation of the weaning weight of beef cattle as a function of accumulated heat stress.

    PubMed

    Santana, M L; Bignardi, A B; Eler, J P; Ferraz, J B S

    2016-04-01

    The objective of this study was to identify the genetic variation in the weaning weight (WW) of beef cattle as a function of heat stress. The WWs were recorded at approximately 205 days of age in three Brazilian beef cattle populations: Nelore (93,616), Brangus (18,906) and Tropical Composite (62,679). In view of the cumulative nature of WW, the effect of heat stress was considered as the accumulation of temperature and humidity index units (ACTHI) from the animal's birth to weaning. A reaction norm model was used to estimate the (co)variance components of WW across the ACTHI scale. The accumulation of THI units from birth to weaning negatively affected the WW. The definition of accumulated THI units as an environmental descriptor permitted to identify important genetic variation in the WW as a function of heat stress. As evidence of genotype by environment interaction, substantial heterogeneity was observed in the (co)variance components for WW across the environmental gradient. In this respect, the best animals in less stressful environments are not necessarily the best animals in more stressful environments. Furthermore, the response to selection for WW is expected to be lower in more stressful environments. PMID:26061790

  10. Visualization of Anatomic Variation of the Anterior Septal Vein on Susceptibility-Weighted Imaging

    PubMed Central

    Chen, Zhengzhen; Qiao, Huihuang; Guo, Yu; Li, Jiance; Miao, Huizhong; Wen, Caiyun; Wen, Xindong; Zhang, Xiaofen; Yang, Xindong; Chen, Chengchun

    2016-01-01

    Background and Purpose Understanding the anatomy of the anterior septal vein (ASV) is critical for minimally invasive procedures to the third ventricle and for assessing lesion size and venous drainage in the anterior cranial fossa. Accordingly, this study evaluated topographic anatomy and anatomic variation of the ASV using susceptibility-weighted imaging (SWI). Methods Sixty volunteers were examined using a 3.0T MR system. The diameter of the ASV and distance between bilateral septal points were measured. ASVs were divided into types 1 (only drains frontal lobe) and 2 (drains both frontal lobe and head of the caudate nucleus). We evaluated the ASV-internal cerebral vein (ICV) junction based on its positional relationship with the appearance of a venous angle or a false venous angle and the foramen of Monro. Fused SW and T1-weighted images were used to observe positional relationships between the course of the ASV and the surrounding brain structures. Results The ASV and its small tributaries were clearly visualized in 120 hemispheres (100%). The average diameter of ASVs was 1.05±0.17 mm (range 0.9–1.6 mm). The average distance between bilateral septal points was 2.23±1.03 mm (range 1.3–6.6 mm). The ASV types 1 and 2 were in 77 (64.2%) and 43 (35.8%) hemispheres, respectively. In 83 (69.2%) hemispheres, the ASV-ICV junction was situated at the venous angle and the posterior margin of the foramen of Monro. In 37 (30.8%) hemispheres, the ASV-ICV junction was situated beyond the posterior margin of the foramen of Monro. The average distance between the posteriorly located ASV-ICV junction and the posterior margin of the foramen of Monro was 6.41±3.95 mm (range 2.4–15.9 mm). Conclusion Using SWI, the topographic anatomy and anatomic variation of the ASV were clearly demonstrated. Preoperative assessment of anatomic variation of the ASV may be advantageous for minimally invasive neurosurgical procedures. PMID:27716782

  11. QTL Location and Epistatic Effect Analysis of 100-Seed Weight Using Wild Soybean (Glycine soja Sieb. & Zucc.) Chromosome Segment Substitution Lines

    PubMed Central

    Zhu, Rongsheng; Hu, Jiahui; Han, Heyu; Hu, Guohua; Liu, Chunyan; Chen, Qingshan

    2016-01-01

    Increasing the yield of soybean (Glycine max L. Merrill) is a main aim of soybean breeding. The 100-seed weight is a critical factor for soybean yield. To facilitate genetic analysis of quantitative traits and to improve the accuracy of marker-assisted breeding in soybean, a valuable mapping population consisting of 194 chromosome segment substitution lines (CSSLs) was developed. In these lines, different chromosomal segments of the Chinese cultivar Suinong 14 were substituted into the genetic background of wild soybean (Glycine soja Sieb. & Zucc.) ZYD00006. Based on these CSSLs, a genetic map covering the full genome was generated using 121 simple sequence repeat (SSR) markers. In the quantitative trait loci (QTL) analysis, twelve main effect QTLs (qSW-B1-1/2/3, qSW-D1b-1/2, qSW-D2-1/2, qSW-G-1/2/3, qSW-M-2 and qSW-N-2) underlying 100-seed weight were identified in 2011 and 2012. The epistatic effects of pairwise interactions between markers were analyzed in 2011 and 2012. The results clearly demonstrated that these CSSLs could be used to identify QTLs, and that an epistatic analysis was able to detect several sites with important epistatic effects on 100-seed weight. Thus, we identified loci that will be valuable for improving soybean 100-seed weight. These results provide a valuable foundation for identifying the precise location of genes of interest, and for designing cloning and marker-assisted selection breeding strategies targeting the 100-seed weight of soybean. PMID:26934088

  12. QTL Location and Epistatic Effect Analysis of 100-Seed Weight Using Wild Soybean (Glycine soja Sieb. & Zucc.) Chromosome Segment Substitution Lines.

    PubMed

    Xin, Dawei; Qi, Zhaoming; Jiang, Hongwei; Hu, Zhenbang; Zhu, Rongsheng; Hu, Jiahui; Han, Heyu; Hu, Guohua; Liu, Chunyan; Chen, Qingshan

    2016-01-01

    Increasing the yield of soybean (Glycine max L. Merrill) is a main aim of soybean breeding. The 100-seed weight is a critical factor for soybean yield. To facilitate genetic analysis of quantitative traits and to improve the accuracy of marker-assisted breeding in soybean, a valuable mapping population consisting of 194 chromosome segment substitution lines (CSSLs) was developed. In these lines, different chromosomal segments of the Chinese cultivar Suinong 14 were substituted into the genetic background of wild soybean (Glycine soja Sieb. & Zucc.) ZYD00006. Based on these CSSLs, a genetic map covering the full genome was generated using 121 simple sequence repeat (SSR) markers. In the quantitative trait loci (QTL) analysis, twelve main effect QTLs (qSW-B1-1/2/3, qSW-D1b-1/2, qSW-D2-1/2, qSW-G-1/2/3, qSW-M-2 and qSW-N-2) underlying 100-seed weight were identified in 2011 and 2012. The epistatic effects of pairwise interactions between markers were analyzed in 2011 and 2012. The results clearly demonstrated that these CSSLs could be used to identify QTLs, and that an epistatic analysis was able to detect several sites with important epistatic effects on 100-seed weight. Thus, we identified loci that will be valuable for improving soybean 100-seed weight. These results provide a valuable foundation for identifying the precise location of genes of interest, and for designing cloning and marker-assisted selection breeding strategies targeting the 100-seed weight of soybean.

  13. Spatial variation in post-dispersal seed removal in an Atlantic forest: Effects of habitat, location and guilds of seed predators

    NASA Astrophysics Data System (ADS)

    Christianini, Alexander V.; Galetti, Mauro

    2007-11-01

    Studies of post-dispersal seed removal in the Neotropics have rarely examined the magnitude of seed removal by different types of granivores. The relative impact of invertebrates, small rodents, and birds on seed removal was investigated in a 2,178 ha Atlantic forest fragment in southeastern Brazil. We used popcorn kernels ( Zea mays—Poaceae) to investigate seed removal in a series of selective exclosure treatments in a replicated, paired design experiment that included forest understory, gaps, and forest edge sites. We recorded the vegetation around the experimental seed stations in detail in order to evaluate the influence of microhabitat traits on seed removal. Vertebrate granivores (rodents and birds) were surveyed to determine whether granivore abundance was correlated with seed removal levels. Seed removal varied spatially and in unpredictable ways at the study site. Seed encounter and seed use varied with treatments, but not with habitat type. However, seed removal by invertebrates was negatively correlated with gap-related traits, which suggested an avoidance of large gaps by granivorous ants. The abundance of small mammals was remarkably low, but granivorous birds (tinamous and doves) were abundant at the study site. Birds were the main seed consumers in open treatments, but there was no correlation between local granivorous bird abundance and seed removal. These results emphasize the stochastic spatial pattern of seed removal, and, contrary to previous studies, highlight the importance of birds as seed predators in forest habitats.

  14. Variation in seed germination of 134 common species on the eastern Tibetan Plateau: phylogenetic, life history and environmental correlates.

    PubMed

    Xu, Jing; Li, Wenlong; Zhang, Chunhui; Liu, Wei; Du, Guozhen

    2014-01-01

    Seed germination is a crucial stage in the life history of a species because it represents the pathway from adult to offspring, and it can affect the distribution and abundance of species in communities. In this study, we examined the effects of phylogenetic, life history and environmental factors on seed germination of 134 common species from an alpine/subalpine meadow on the eastern Tibetan Plateau. In one-way ANOVAs, phylogenetic groups (at or above order) explained 13.0% and 25.9% of the variance in germination percentage and mean germination time, respectively; life history attributes, such as seed size, dispersal mode, explained 3.7%, 2.1% of the variance in germination percentage and 6.3%, 8.7% of the variance in mean germination time, respectively; the environmental factors temperature and habitat explained 4.7%, 1.0% of the variance in germination percentage and 13.5%, 1.7% of the variance in mean germination time, respectively. Our results demonstrated that elevated temperature would lead to a significant increase in germination percentage and an accelerated germination. Multi-factorial ANOVAs showed that the three major factors contributing to differences in germination percentage and mean germination time in this alpine/subalpine meadow were phylogenetic attributes, temperature and seed size (explained 10.5%, 4.7% and 1.4% of the variance in germination percentage independently, respectively; and explained 14.9%, 13.5% and 2.7% of the variance in mean germination time independently, respectively). In addition, there were strong associations between phylogenetic group and life history attributes, and between life history attributes and environmental factors. Therefore, germination variation are constrained mainly by phylogenetic inertia in a community, and seed germination variation correlated with phylogeny is also associated with life history attributes, suggesting a role of niche adaptation in the conservation of germination variation within lineages

  15. Geographic variation in speed of seed germination in central Oregon ponderosa pine ( pinus ponderosa' dougl. ex laws). Forest Service research paper

    SciTech Connect

    Weber, J.C.; Sorensen, F.C.

    1992-03-01

    Variation in speed of seed germination was investigated among ponderosa pine trees representing 225 locations in central Oregon. Results suggested that at least some of the geographic variation is related to the severity of summer drought. In general, germination speed was greater in locations with short, drought-limited growing seasons. Levels of geographic variation were highest in the region having the steepest precipitation gradients. Most of the variation occurred, however, within locations.

  16. Genetic variation and seed zones of douglas-fir in the Siskiyou National Forest. Forest Service research paper

    SciTech Connect

    Campbell, R.K.; Sugano, A.I.

    1993-07-01

    The provisional seed zones and breeding zones were developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Siskiyou National Forest in southwestern Oregon. Zones were based on maps of genetic variation patterns obtained by evaluating genotypes of trees from 260 locations in the region. Genotypes controlling growth vigor and growth rhythm were assessed in the common garden. Within the Forest, three breeding blocks were recommended, with different numbers of elevational bands in each block: from 0 to 610 meters, from 611 to 838 meters, and then a series of bands 152 meters wide at higher elevations.

  17. Susceptibility-Weighted Imaging of the Anatomic Variation of Thalamostriate Vein and Its Tributaries

    PubMed Central

    Zhang, Xiao-fen; Li, Jian-ce; Wen, Xin-dong; Ren, Chuan-gen; Cai, Ming; Chen, Cheng-chun

    2015-01-01

    Background and Purpose Thalamostriate vein (TSV) is an important tributary of the internal cerebral vein, which mainly drains the basal ganglia and deep medulla. The purpose of this study was to explore the anatomic variation and quality of TSV and its smaller tributaries using susceptibility-weighted imaging (SWI). Methods We acquired SWI images in 40 volunteers on a 3.0T MR system using an 8-channel high-resolution phased array coil. The frequencies of the TSV and its tributaries were evaluated. We classified TSV into types I (forming a venous angle) and II (forming a false venous angle). We classified anterior caudate vein (ACV)into types 1 (1 trunk) and 2 (2 trunks) as well as into types A (joiningTSV), B (joining anterior septal vein), and C (joining the angle of both veins). Results The TSV drains the areas of caudate nucleus, internal capsule,lentiform nucleus, external capsule, claustrum, extreme capsule and the white matter of the frontoparietal lobes,except thalamus. The frequencies of the TSV, ACV and transverse caudate vein (ACV) were 92.5%, 87.5% and 63.8%, respectively. We found TSV types I and II in 79.7%, and 20.3% with significantly different constitution ratios (P< 0.05). The most common types of ACV were type 1 (90.0%) and type A (64.3%). Conclusion The complex three-dimensional (3D) venous architecture of TSV and its small tributaries manifests great variation, with significant and practical implications for neurosurgery. PMID:26506095

  18. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana

    PubMed Central

    Pelc, Sandra E; Linder, C Randal

    2015-01-01

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high- and low-melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high-melting point lines had lower fitness relative to those against low-melting point lines, which matched expectations for undifferentiated emergence times. PMID:25628873

  19. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated...

  20. Emergence timing and fitness consequences of variation in seed oil composition in Arabidopsis thaliana.

    PubMed

    Pelc, Sandra E; Linder, C Randal

    2015-01-01

    Early seedling emergence can increase plant fitness under competition. Seed oil composition (the types and relative amounts of fatty acids in the oils) may play an important role in determining emergence timing and early growth rate in oilseeds. Saturated fatty acids provide more energy per carbon atom than unsaturated fatty acids but have substantially higher melting points (when chain length is held constant). This characteristic forms the basis of an adaptive hypothesis that lower melting point seeds (lower proportion of saturated fatty acids) should be favored under colder germination temperatures due to earlier germination and faster growth before photosynthesis, while at warmer germination temperatures, seeds with a higher amount of energy (higher proportion of saturated fatty acids) should be favored. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, high- and low-melting point lines from a recombinant inbred cross of Arabidopsis thaliana were competed in a fully factorial experiment at warm and cold temperatures with two different density treatments. Emergence timing between these lines was not significantly different at either temperature, which aligned with warm temperature predictions, but not cold temperature predictions. Under all conditions, plants competing against high-melting point lines had lower fitness relative to those against low-melting point lines, which matched expectations for undifferentiated emergence times. PMID:25628873

  1. Historic Variations in Winter Indoor Domestic Temperatures and Potential Implications for Body Weight Gain

    PubMed Central

    Johnson, F.; Ucci, M.; Marmot, A.; Wardle, J.; Oreszczyn, T.; Summerfield, A.

    2013-01-01

    It has been argued that the amount of time spent by humans in thermoneutral environments has increased in recent decades. This paper examines evidence of historic changes in winter domestic temperatures in industrialised countries. Future trajectories for indoor thermal comfort are also explored. Whilst methodological differences across studies make it difficult to compare data and accurately estimate the absolute size of historic changes in indoor domestic temperatures, data analysis does suggest an upward trend, particularly in bedrooms. The variations in indoor winter residential temperatures might have been further exacerbated in some countries by a temporary drop in demand temperatures due to the 1970s energy crisis, as well as by recent changes in the building stock. In the United Kingdom, for example, spot measurement data indicate that an increase of up to 1.3°C per decade in mean dwelling winter indoor temperatures may have occurred from 1978 to 1996. The findings of this review paper are also discussed in the context of their significance for human health and well-being. In particular, historic indoor domestic temperature trends are discussed in conjunction with evidence on the links between low ambient temperatures, body energy expenditure and weight gain. PMID:26321874

  2. Adjoint-weighted variational formulation for a direct computational solution of an inverse heat conduction problem

    NASA Astrophysics Data System (ADS)

    Barbone, Paul E.; Oberai, Assad A.; Harari, Isaac

    2007-12-01

    We consider the direct (i.e. non-iterative) solution of the inverse problem of heat conduction for which at least two interior temperature fields are available. The strong form of the problem for the single, unknown, thermal conductivity field is governed by two partial differential equations of pure advective transport. The given temperature fields must satisfy a compatibility condition for the problem to have a solution. We introduce a novel variational formulation, the adjoint-weighted equation (AWE), for solving the two-field problem. In this case, the gradients of two given temperature fields must be linearly independent in the entire domain, a weaker condition than the compatibility required by the strong form. We show that the solution of the AWE formulation is equivalent to that of the strong form when both are well posed. We prove that the Galerkin discretization of the AWE formulation leads to a stable, convergent numerical method that has optimal rates of convergence. We show computational examples that confirm these optimal rates. The AWE formulation shows good numerical performance on problems with both smooth and rough coefficients and solutions.

  3. Observation of a 100-MHz frequency variation across the output of a frequency-doubled injection-seeded unstable-resonator Q-switched Nd:YAG laser.

    PubMed

    Forkey, J N; Lempert, W R; Miles, R B

    1997-02-15

    We report high-resolution measurements of the spatial variation of the optical frequency of an injection-seeded unstable-resonator Q-switched Nd:YAG laser. Images of the second harmonic taken through a molecular-iodine notch filter show frequency variations of as much as 100 MHz (second harmonic) between the center and the edge of the beam. PMID:18183159

  4. Genetic variation in adaptive traits and seed transfer zones for Pseudoroegneria spicata (bluebunch wheatgrass) in the northwestern United States.

    PubMed

    Bradley St Clair, John; Kilkenny, Francis F; Johnson, Richard C; Shaw, Nancy L; Weaver, George

    2013-09-01

    A genecological approach was used to explore genetic variation in adaptive traits in Pseudoroegneria spicata, a key restoration grass, in the intermountain western United States. Common garden experiments were established at three contrasting sites with seedlings from two maternal parents from each of 114 populations along with five commercial releases commonly used in restoration. Traits associated with size, flowering phenology, and leaf width varied considerably among populations and were moderately correlated with the climates of the seed sources. Pseudoroegneria spicata populations from warm, arid source environments were smaller with earlier phenology and had relatively narrow leaves than those from mild climates with cool summers, warm winters, low seasonal temperature differentials, high precipitation, and low aridity. Later phenology was generally associated with populations from colder climates. Releases were larger and more fecund than most of the native ecotypes, but were similar to native populations near their source of origin. Differences among native populations associated with source climates that are logical for survival, growth, and reproduction indicate that genetic variation across the landscape is adaptive and should be considered during restoration. Results were used to delineate seed transfer zones and population movement guidelines to ensure adapted plant materials for restoration activities. PMID:24062802

  5. [Quality classification criteria of Paeonia suffruticosa seeds].

    PubMed

    Cao, Ya-yue; Zhu, Zai-biao; Guo, Qiao-sheng; Liu, Li; Wang, Chang-lin

    2015-02-01

    In order to establish the quality classification criteria of Paeonia suffruticosa seeds, thirty-one batches of P. suffruticosa seeds from different provenances were selected. The seed rooting rate, seed germination rate, seed purity, seed viability, 1,000-seed weight and moisture content were determined and analyzed through SPSS 20.0 software. Seed rooting rate, seed germination rate and seed purity were selected as the main index for classification, while 1,000-seed weight, seed viability and moisture content could be used as important references. The seed quality grading of P. suffruticosa was set as three grades. The seed quality of each grade should meet following requirements: For the first grade seeds, seed rooting rate ≥ 80%, seed germination rate ≥ 80%, seed purity ≥ 90%, seed viability ≥ 80%, 1,000-seed weight ≥ 250 g, moisture content, ≤ 10. For the second grade seeds, seed rooting rate ≥ 50%, seed germination rate ≥ 60%, seed purity ≥ 70%, seed viability ≥ 75%, 1,000-seed weight ≥ 225 g, moisture content ≤ 10. For the third grade seeds, seed rooting rate ≥ 20%, seed germination rate ≥ 45%, seed purity ≥ 60%, seed viability ≥ 45%, 1,000-seed weight ≥ 205 g, moisture content ≤ 10. The quality classification criteria of P. suffruticosa seeds have been initially established.

  6. Seed size variability: from carob to carats

    PubMed Central

    Turnbull, Lindsay A; Santamaria, Luis; Martorell, Toni; Rallo, Joan; Hector, Andy

    2006-01-01

    The seeds of various plants were used as weights because their mass reputedly varies so little. Carob (Ceratonia siliqua), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 species reviewed from the literature (CV=25%). However, in a perception experiment observers could discriminate differences in carob seed weight of around 5% by eye demonstrating the potential for humans to greatly reduce natural variation. Interestingly, the variability of pre-metrication carat weight standards is also around 5% suggesting that human rather than natural selection gave rise to the carob myth. PMID:17148413

  7. Variation in a single protoplast- and seed-derived population of Lotus corniculatus L.

    PubMed

    Niizeki, M; Ishikawa, R; Saito, K

    1990-12-01

    Lotus comiculatus L. is a widely cultivated, outbreeding, leguminous forage crop. Seventy-one plants, most of which were tetraploid, were regenerated from calli derived from a single protoplast. Their morphological and agronomic traits were evaluated and compared with those of the seed-produced population. The variances of most of the traits in the protoplast-derived (protoclonal) population were smaller than those of the seed-produced population. Mean values of all the traits of the protoclonal population shifted significantly towards lower values. However, new phenotypic variants with higher values than those of the plant initially used for protoplast isolation were also observed. Plants with less hydrocyanic acid (which has a toxic effect on cattle) than the initial plant were obtained in the protoclones. Generally, the pollen fertility of protoclones was significantly low compared with the seed-produced plants. This seems to be partly due to the occurrence of abnormalities in chromosome structure during protoplast and/or callus culture, as suggested by the formation of univalents, lagging, and fragment chromosomes and bridges at metaphase I and anaphase I and II of the regenerants. The changes in chromosome structure, however, did not induce any malformed morphologies. PMID:24221102

  8. Variation in oil content, fatty acid and phytosterols profile of Onopordum acanthium L. during seed development.

    PubMed

    Arfaoui, Moufida Oueslati; Renaud, Justin; Ghazghazi, Hanen; Boukhchina, Sadok; Mayer, Paul

    2014-01-01

    This study has determined oil, fatty acid (FA) and phytosterols content during the ripening of the Tunisian Onopordum acanthium L. seeds. In total, nine FAs and six phytosterols were identified. The main FAs were linoleic acid (0.18-8.06 mg/g of seed) followed by oleic acid (0.051-2.45 mg/g of seed), palmitic acid and stearic acid. Pentadecanoic acid was detected, for the first time, in unripe fruits and the two last stages of development were characterised by a relative abundance of erucic acid. Overall, β-sitosterol (34.5-77.79% of total sterols) was the major 4-desmethylsterols during maturation. The first episodes of growth were characterised by the best amounts of stigmasterol and campesterol, while stigmastanol and Δ7 sitosterol had quoted the semi-ripe and fully ripe fruits; however, cholesterol was absent. These findings are useful in understanding a potential new source of important natural compounds (Phytosterols and USFA) found in this fruit and when harvest should be undertaken to optimise desired FA and phytosterols content.

  9. Over-Expression of a Tobacco Nitrate Reductase Gene in Wheat (Triticum aestivum L.) Increases Seed Protein Content and Weight without Augmenting Nitrogen Supplying

    PubMed Central

    Zhao, Xiao-Qiang; Nie, Xuan-Li; Xiao, Xing-Guo

    2013-01-01

    Heavy nitrogen (N) application to gain higher yield of wheat (Triticum aestivum L.) resulted in increased production cost and environment pollution. How to diminish the N supply without losing yield and/or quality remains a challenge. To meet the challenge, we integrated and expressed a tobacco nitrate reductase gene (NR) in transgenic wheat. The 35S-NR gene was transferred into two winter cultivars, “Nongda146” and “Jimai6358”, by Agrobacterium-mediation. Over-expression of the transgene remarkably enhanced T1 foliar NR activity and significantly augmented T2 seed protein content and 1000-grain weight in 63.8% and 68.1% of T1 offspring (total 67 individuals analyzed), respectively. Our results suggest that constitutive expression of foreign nitrate reductase gene(s) in wheat might improve nitrogen use efficiency and thus make it possible to increase seed protein content and weight without augmenting N supplying. PMID:24040315

  10. Molecular weight and galloylation affect grape seed extract constituents’ ability to cross-link dentin collagen in clinically relevant time

    PubMed Central

    Liu, Yi; Bai, Xinyan; Li, Shaohua; Liu, Ying; Keightley, Andrew; Wang, Yong

    2015-01-01

    Objective To investigate the relationship between the structures of polyphenolic compounds found in grape seed extract (GSE) and their activity in cross-linking dentin collagen in clinically relevant settings. Methods Representative monomeric and dimeric GSE constituents including (+)-catechin (pCT), (−)-catechin (CT), (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG), (−)-epigallocatechin gallate (EGCG), procyanidin B2 and a pCT-pCT dimer were purchased or synthesized. GSE was separated into low (PALM) and high molecular weight (PAHM) fractions. Human molars were processed into dentin films and beams. After demineralization, 11 groups of films (n=5) were treated for 1 min with the aforementioned reagents (1 wt% in 50/50 ethanol/water) and 1 group remained untreated. The films were studied by Fourier transform infrared spectroscopy (FTIR) followed by a quantitative mass spectroscopy-based digestion assay. Tensile properties of demineralized dentin beams were evaluated (n=7) after treatments (2h and 24h) with selective GSE species that were found to protect dentin collagen from collagenase. Results Efficacy of GSE constituents in cross-linking dentin collagen was dependent on molecular size and galloylation. Non-galloylated species with degree of polymerization up to two, including pCT, CT, EC, EGC, procyanidin B2 and pCT-pCT dimer were not active. Galloylated species were active starting from monomeric form, including ECG, EGCG, PALM, GSE and PAHM. PALM induced the best overall improvement in tensile properties of dentin collagen. Significance Identification under clinically relevant settings of structural features that contribute to GSE constituents’ efficacy in stabilizing demineralized dentin matrix has immediate impact on optimizing GSE’s use in dentin bonding. PMID:25958268

  11. Structure-adaptive CBCT reconstruction using weighted total variation and Hessian penalties

    PubMed Central

    Shi, Qi; Sun, Nanbo; Sun, Tao; Wang, Jing; Tan, Shan

    2016-01-01

    The exposure of normal tissues to high radiation during cone-beam CT (CBCT) imaging increases the risk of cancer and genetic defects. Statistical iterative algorithms with the total variation (TV) penalty have been widely used for low dose CBCT reconstruction, with state-of-the-art performance in suppressing noise and preserving edges. However, TV is a first-order penalty and sometimes leads to the so-called staircase effect, particularly over regions with smooth intensity transition in the reconstruction images. A second-order penalty known as the Hessian penalty was recently used to replace TV to suppress the staircase effect in CBCT reconstruction at the cost of slightly blurring object edges. In this study, we proposed a new penalty, the TV-H, which combines TV and Hessian penalties for CBCT reconstruction in a structure-adaptive way. The TV-H penalty automatically differentiates the edges, gradual transition and uniform local regions within an image using the voxel gradient, and adaptively weights TV and Hessian according to the local image structures in the reconstruction process. Our proposed penalty retains the benefits of TV, including noise suppression and edge preservation. It also maintains the structures in regions with gradual intensity transition more successfully. A majorization-minimization (MM) approach was designed to optimize the objective energy function constructed with the TV-H penalty. The MM approach employed a quadratic upper bound of the original objective function, and the original optimization problem was changed to a series of quadratic optimization problems, which could be efficiently solved using the Gauss-Seidel update strategy. We tested the reconstruction algorithm on two simulated digital phantoms and two physical phantoms. Our experiments indicated that the TV-H penalty visually and quantitatively outperformed both TV and Hessian penalties.

  12. Structure-adaptive CBCT reconstruction using weighted total variation and Hessian penalties

    PubMed Central

    Shi, Qi; Sun, Nanbo; Sun, Tao; Wang, Jing; Tan, Shan

    2016-01-01

    The exposure of normal tissues to high radiation during cone-beam CT (CBCT) imaging increases the risk of cancer and genetic defects. Statistical iterative algorithms with the total variation (TV) penalty have been widely used for low dose CBCT reconstruction, with state-of-the-art performance in suppressing noise and preserving edges. However, TV is a first-order penalty and sometimes leads to the so-called staircase effect, particularly over regions with smooth intensity transition in the reconstruction images. A second-order penalty known as the Hessian penalty was recently used to replace TV to suppress the staircase effect in CBCT reconstruction at the cost of slightly blurring object edges. In this study, we proposed a new penalty, the TV-H, which combines TV and Hessian penalties for CBCT reconstruction in a structure-adaptive way. The TV-H penalty automatically differentiates the edges, gradual transition and uniform local regions within an image using the voxel gradient, and adaptively weights TV and Hessian according to the local image structures in the reconstruction process. Our proposed penalty retains the benefits of TV, including noise suppression and edge preservation. It also maintains the structures in regions with gradual intensity transition more successfully. A majorization-minimization (MM) approach was designed to optimize the objective energy function constructed with the TV-H penalty. The MM approach employed a quadratic upper bound of the original objective function, and the original optimization problem was changed to a series of quadratic optimization problems, which could be efficiently solved using the Gauss-Seidel update strategy. We tested the reconstruction algorithm on two simulated digital phantoms and two physical phantoms. Our experiments indicated that the TV-H penalty visually and quantitatively outperformed both TV and Hessian penalties. PMID:27699100

  13. Study Of Seed Yield Correlation With Different Traits Of Common Bean Under Stress Condition

    NASA Astrophysics Data System (ADS)

    Aminian, Roghayeh; Khodambashi, Mahmood; Yadegari, Mehrab

    2008-01-01

    In order to study seed yield and the most effective traits on seed yield of ten common been cultivars, a split plot in the form of complete block design was conducted at Shahrekord University. Among the characters studied, seed yield had the highest variation and the weight of plants had the lowest variation. the number of pods per plant had the highest correlation with seed yield in both stress and non stress conditions, while the number of seed per plant and 100 seeds weight had the lowest correlation with seed yield in non stress and stress conditions, respectively. Increase in stress intensity caused the increase in correlation between seed yield and the total weight of plant and the number of seed per pod. In principal components analysis, number of pods per plant, number of seeds per pods and seed yield had the highest correlation with the first component while 100 seeds weight and number of seeds per plant had the highest correlation with the second component.

  14. Genome-Wide Association Study in Arabidopsis thaliana of Natural Variation in Seed Oil Melting Point: A Widespread Adaptive Trait in Plants.

    PubMed

    Branham, Sandra E; Wright, Sara J; Reba, Aaron; Morrison, Ginnie D; Linder, C Randal

    2016-05-01

    Seed oil melting point is an adaptive, quantitative trait determined by the relative proportions of the fatty acids that compose the oil. Micro- and macro-evolutionary evidence suggests selection has changed the melting point of seed oils to covary with germination temperatures because of a trade-off between total energy stores and the rate of energy acquisition during germination under competition. The seed oil compositions of 391 natural accessions of Arabidopsis thaliana, grown under common-garden conditions, were used to assess whether seed oil melting point within a species varied with germination temperature. In support of the adaptive explanation, long-term monthly spring and fall field temperatures of the accession collection sites significantly predicted their seed oil melting points. In addition, a genome-wide association study (GWAS) was performed to determine which genes were most likely responsible for the natural variation in seed oil melting point. The GWAS found a single highly significant association within the coding region of FAD2, which encodes a fatty acid desaturase central to the oil biosynthesis pathway. In a separate analysis of 15 a priori oil synthesis candidate genes, 2 (FAD2 and FATB) were located near significant SNPs associated with seed oil melting point. These results comport with others' molecular work showing that lines with alterations in these genes affect seed oil melting point as expected. Our results suggest natural selection has acted on a small number of loci to alter a quantitative trait in response to local environmental conditions.

  15. Genome-Wide Association Study in Arabidopsis thaliana of Natural Variation in Seed Oil Melting Point: A Widespread Adaptive Trait in Plants.

    PubMed

    Branham, Sandra E; Wright, Sara J; Reba, Aaron; Morrison, Ginnie D; Linder, C Randal

    2016-05-01

    Seed oil melting point is an adaptive, quantitative trait determined by the relative proportions of the fatty acids that compose the oil. Micro- and macro-evolutionary evidence suggests selection has changed the melting point of seed oils to covary with germination temperatures because of a trade-off between total energy stores and the rate of energy acquisition during germination under competition. The seed oil compositions of 391 natural accessions of Arabidopsis thaliana, grown under common-garden conditions, were used to assess whether seed oil melting point within a species varied with germination temperature. In support of the adaptive explanation, long-term monthly spring and fall field temperatures of the accession collection sites significantly predicted their seed oil melting points. In addition, a genome-wide association study (GWAS) was performed to determine which genes were most likely responsible for the natural variation in seed oil melting point. The GWAS found a single highly significant association within the coding region of FAD2, which encodes a fatty acid desaturase central to the oil biosynthesis pathway. In a separate analysis of 15 a priori oil synthesis candidate genes, 2 (FAD2 and FATB) were located near significant SNPs associated with seed oil melting point. These results comport with others' molecular work showing that lines with alterations in these genes affect seed oil melting point as expected. Our results suggest natural selection has acted on a small number of loci to alter a quantitative trait in response to local environmental conditions. PMID:26865732

  16. Adolescent obesity, change in weight status, and hypertension: racial/ethnic variations.

    PubMed

    Suglia, Shakira F; Clark, Cari J; Gary-Webb, Tiffany L

    2013-02-01

    We sought to determine whether change in weight status between adolescence and young adulthood was associated with the risk of developing hypertension among adolescents and whether sex and racial/ethnic group differences existed in the National Longitudinal Study of Adolescent Health. The sample was restricted to participants who self-identified as black, Hispanic, or white non-Hispanic (n=8543). Height and weight were measured in adolescence (mean 16 years) and again in adulthood (mean 29 years). We categorized the weight of participants into 4 groups: stayed normal weight; gained weight (normal weight in adolescence and obese in adulthood); lost weight (overweight/obese in adolescence nonobese in adulthood); and chronically overweight/obese. Hypertension was defined as measured systolic blood pressure of at least 140 mm Hg or diastolic blood pressure of at least 90 mm Hg measured in adulthood or use of antihypertensive medications. A higher risk of hypertension was noted for all sex and racial/ethnic groups who became obese in adulthood. Furthermore, those who were chronically overweight/obese were at higher risk of hypertension for all groups, with odds ratios ranging from 2.7 in Hispanic men to 6.5 in Hispanic women. Except for black men, those who lost weight during follow-up had no significant increased risk compared with those who maintained normal weight. Overall, there was an increased risk of hypertension for those who gained weight in adulthood and among those who remained obese from adolescence to young adulthood. These data give further evidence for prevention strategies that begin earlier in life to reduce or delay the onset of chronic disease in young adults.

  17. Proteomic analysis of peanut seed storage proteins and genetic variation in a potential peanut allergen.

    PubMed

    Guo, Baozhu; Liang, Xianquiang; Chung, Si-Yin; Holbrook, C Corley; Maleki, Soheila J

    2008-01-01

    Peanut allergy is one of the most severe food allergies. One effort to alleviate this problem is to identify peanut germplasm with lower levels of allergens which could be used in conventional breeding to produce a less allergenic peanut cultivar. In this study, we identified one peanut line, GT-C9, lacking several seed proteins, which were identified as Ara h 3 isoforms by peptide sequencing and named iso-Ara h 3. Total seed proteins were analyzed by one-dimensional (SDS-PAGE) and two-dimensional gel electrophoreses (2-D PAGE). The total protein extracts were also tested for levels of protein-bound end products or adducts such as advanced glycation end products (AGE) and N-(carboxymethyl) lysine (CML), and IgE binding. Peanut genotypes of GT-C9 and GT-C20 exhibited significantly lower levels of AGE adducts and of IgE binding. This potential peanut allergen iso-Ara h 3 was confirmed by peptide sequences and Western blot analysis using specific anti-Ara h 1, Ara h 2, and Ara h 3 antibodies. A full-length sequence of iso-ara h 3 (GenBank number DQ855115) was obtained. The deduced amino acid sequence iso-Ara h 3 (ABI17154) has the first three of four IgE-binding epitopes of Ara h 3. Anti-Ara h 3 antibodies reacted with two groups of protein peptides, one with strong reactions and another with weak reactions. These peptide spots with weak reaction on 2-D PAGE to anti-Ara h 3 antibodies are subunits or isoallergens of this potential peanut allergen iso-Ara h 3. A recent study suggested that Ara h 3 basic subunits may be more significant allergenicity than the acidic subunits.

  18. Natural Genetic Variation of Seed Micronutrients of Arabidopsis thaliana Grown in Zinc-Deficient and Zinc-Amended Soil

    PubMed Central

    Chen, Xiaochao; Yuan, Lixing; Ludewig, Uwe

    2016-01-01

    The quality of edible seeds for human and animal nutrition is crucially dependent on high zinc (Zn) and iron (Fe) seed concentrations. The micronutrient bioavailability is strongly reduced by seed phytate that forms complexes with seed cations. Superior genotypes with increased seed Zn concentrations had been identified, but low micronutrient seed levels often prevail when the plants are grown in Zn-deficient soils, which are globally widespread and correlate with human Zn-deficiency. Here, seed Zn concentrations of Arabidopsis accessions grown in Zn-deficient and Zn-amended conditions were measured together with seed Fe and manganese (Mn), in a panel of 108 accessions. By applying genome-wide association, de novo candidate genes potentially involved in the seed micronutrient accumulation were identified. However, a candidate inositol 1,3,4-trisphosphate 5/6-kinase 3 gene (ITPK3), located close to a significant nucleotide polymorphism associated with relative Zn seed concentrations, was dispensable for seed micronutrients accumulation in Col-0. Loss of this gene in itpk3-1 did neither affect phytate seed levels, nor seed Zn, Fe, and Mn. It is concluded that large natural variance of micronutrient seed levels is identified in the population and several accessions maintain high seed Zn despite growth in Zn-deficient conditions. PMID:27507976

  19. Natural Genetic Variation of Seed Micronutrients of Arabidopsis thaliana Grown in Zinc-Deficient and Zinc-Amended Soil.

    PubMed

    Chen, Xiaochao; Yuan, Lixing; Ludewig, Uwe

    2016-01-01

    The quality of edible seeds for human and animal nutrition is crucially dependent on high zinc (Zn) and iron (Fe) seed concentrations. The micronutrient bioavailability is strongly reduced by seed phytate that forms complexes with seed cations. Superior genotypes with increased seed Zn concentrations had been identified, but low micronutrient seed levels often prevail when the plants are grown in Zn-deficient soils, which are globally widespread and correlate with human Zn-deficiency. Here, seed Zn concentrations of Arabidopsis accessions grown in Zn-deficient and Zn-amended conditions were measured together with seed Fe and manganese (Mn), in a panel of 108 accessions. By applying genome-wide association, de novo candidate genes potentially involved in the seed micronutrient accumulation were identified. However, a candidate inositol 1,3,4-trisphosphate 5/6-kinase 3 gene (ITPK3), located close to a significant nucleotide polymorphism associated with relative Zn seed concentrations, was dispensable for seed micronutrients accumulation in Col-0. Loss of this gene in itpk3-1 did neither affect phytate seed levels, nor seed Zn, Fe, and Mn. It is concluded that large natural variance of micronutrient seed levels is identified in the population and several accessions maintain high seed Zn despite growth in Zn-deficient conditions. PMID:27507976

  20. A combinatorial approach of comprehensive QTL-based comparative genome mapping and transcript profiling identified a seed weight-regulating candidate gene in chickpea.

    PubMed

    Bajaj, Deepak; Upadhyaya, Hari D; Khan, Yusuf; Das, Shouvik; Badoni, Saurabh; Shree, Tanima; Kumar, Vinod; Tripathi, Shailesh; Gowda, C L L; Singh, Sube; Sharma, Shivali; Tyagi, Akhilesh K; Chattopdhyay, Debasis; Parida, Swarup K

    2015-01-01

    High experimental validation/genotyping success rate (94-96%) and intra-specific polymorphic potential (82-96%) of 1536 SNP and 472 SSR markers showing in silico polymorphism between desi ICC 4958 and kabuli ICC 12968 chickpea was obtained in a 190 mapping population (ICC 4958 × ICC 12968) and 92 diverse desi and kabuli genotypes. A high-density 2001 marker-based intra-specific genetic linkage map comprising of eight LGs constructed is comparatively much saturated (mean map-density: 0.94 cM) in contrast to existing intra-specific genetic maps in chickpea. Fifteen robust QTLs (PVE: 8.8-25.8% with LOD: 7.0-13.8) associated with pod and seed number/plant (PN and SN) and 100 seed weight (SW) were identified and mapped on 10 major genomic regions of eight LGs. One of 126.8 kb major genomic region harbouring a strong SW-associated robust QTL (Caq'SW1.1: 169.1-171.3 cM) has been delineated by integrating high-resolution QTL mapping with comprehensive marker-based comparative genome mapping and differential expression profiling. This identified one potential regulatory SNP (G/A) in the cis-acting element of candidate ERF (ethylene responsive factor) TF (transcription factor) gene governing seed weight in chickpea. The functionally relevant molecular tags identified have potential to be utilized for marker-assisted genetic improvement of chickpea.

  1. In situ adaptive response to climate and habitat quality variation: spatial and temporal variation in European badger (Meles meles) body weight.

    PubMed

    Byrne, Andrew W; Fogarty, Ursula; O'Keeffe, James; Newman, Chris

    2015-09-01

    Variation in climatic and habitat conditions can affect populations through a variety of mechanisms, and these relationships can act at different temporal and spatial scales. Using post-mortem badger body weight records from 15 878 individuals captured across the Republic of Ireland (7224 setts across ca. 15 000 km(2) ; 2009-2012), we employed a hierarchical multilevel mixed model to evaluate the effects of climate (rainfall and temperature) and habitat quality (landscape suitability), while controlling for local abundance (unique badgers caught/sett/year). Body weight was affected strongly by temperature across a number of temporal scales (preceding month or season), with badgers being heavier if preceding temperatures (particularly during winter/spring) were warmer than the long-term seasonal mean. There was less support for rainfall across different temporal scales, although badgers did exhibit heavier weights when greater rainfall occurred one or 2 months prior to capture. Badgers were also heavier in areas with higher landscape habitat quality, modulated by the number of individuals captured per sett, consistent with density-dependent effects reducing weights. Overall, the mean badger body weight of culled individuals rose during the study period (2009-2012), more so for males than for females. With predicted increases in temperature, and rainfall, augmented by ongoing agricultural land conversion in this region, we project heavier individual badger body weights in the future. Increased body weight has been associated with higher fecundity, recruitment and survival rates in badgers, due to improved food availability and energetic budgets. We thus predict that climate change could increase the badger population across the Republic of Ireland. Nevertheless, we emphasize that, locally, populations could still be vulnerable to extreme weather variability coupled with detrimental agricultural practice, including population management.

  2. In situ adaptive response to climate and habitat quality variation: spatial and temporal variation in European badger (Meles meles) body weight.

    PubMed

    Byrne, Andrew W; Fogarty, Ursula; O'Keeffe, James; Newman, Chris

    2015-09-01

    Variation in climatic and habitat conditions can affect populations through a variety of mechanisms, and these relationships can act at different temporal and spatial scales. Using post-mortem badger body weight records from 15 878 individuals captured across the Republic of Ireland (7224 setts across ca. 15 000 km(2) ; 2009-2012), we employed a hierarchical multilevel mixed model to evaluate the effects of climate (rainfall and temperature) and habitat quality (landscape suitability), while controlling for local abundance (unique badgers caught/sett/year). Body weight was affected strongly by temperature across a number of temporal scales (preceding month or season), with badgers being heavier if preceding temperatures (particularly during winter/spring) were warmer than the long-term seasonal mean. There was less support for rainfall across different temporal scales, although badgers did exhibit heavier weights when greater rainfall occurred one or 2 months prior to capture. Badgers were also heavier in areas with higher landscape habitat quality, modulated by the number of individuals captured per sett, consistent with density-dependent effects reducing weights. Overall, the mean badger body weight of culled individuals rose during the study period (2009-2012), more so for males than for females. With predicted increases in temperature, and rainfall, augmented by ongoing agricultural land conversion in this region, we project heavier individual badger body weights in the future. Increased body weight has been associated with higher fecundity, recruitment and survival rates in badgers, due to improved food availability and energetic budgets. We thus predict that climate change could increase the badger population across the Republic of Ireland. Nevertheless, we emphasize that, locally, populations could still be vulnerable to extreme weather variability coupled with detrimental agricultural practice, including population management. PMID:25846328

  3. Variations of Weight of Prostate Gland in Different Age Groups of Bangladeshi Cadaver.

    PubMed

    Epsi, E Z; Khalil, M; Mannan, S; Azam, M S; Ahmed, Z; Farjan, S; Kabir, A; Ara, I; Ajmery, S; Zaman, U K; Amin, S

    2016-07-01

    Now a days, benign prostatic hyperplasia and carcinoma of the prostate are the most common disorders in men. A cross sectional descriptive study was conducted in Department of Anatomy, Mymensingh Medical College, Mymensingh to find out the difference in weight of the prostate gland of Bangladeshi people in relation to age. The present study was performed on 67 postmortem human prostate gland collected from the morgue in the Department of Forensic Medicine, Mymensingh Medical College by non random purposive sampling technique. The specimens were collected from Bangladeshi cadaver of age ranging from 10 to 80 years. All the specimens were grouped into three categories - Group A (upto 18 years), Group B (19 to 45 years) and Group C (above 45 years) according to age. Dissection was performed according to standard autopsy techniques. The weight of the prostate gland were measured and recorded. The mean weight of the prostate gland was 10.13gm in Group A, 17.27gm in Group B and 22.50gm in Group C. Variance analysis shows that mean differences of weight of the prostate were highly significant among all age groups. The weight of prostate gland was found to increase with increased age. For statistical analysis, differences between age groups were analyzed by using students unpaired 't' test. The present study will help to increase the information pool on the weight of prostate gland of Bangladeshi people. PMID:27612887

  4. Temperature thresholds of physically dormant seeds and plant functional response to fire: variation among species and relative impact of climate change

    PubMed Central

    Ooi, Mark K J; Denham, Andrew J; Santana, Victor M; Auld, Tony D

    2014-01-01

    Variation in dormancy thresholds among species is rarely studied but may provide a basis to better understand the mechanisms controlling population persistence. Incorporating dormancy-breaking temperature thresholds into existing trait frameworks could improve predictions regarding seed bank persistence, and subsequently species resilience in response to fire, climate change and anthropogenic management. A key ecological strategy for many species from fire-prone ecosystems is the possession of a long-lived seed bank, ensuring recovery after fire. Physical dormancy is dominant in these ecosystems and maintaining this dormancy is directly linked to seed bank persistence. We identified a suite of seed-related factors relevant to maintaining populations in fire-prone regions for 14 co-occurring physically dormant species. We measured variation in initial levels of dormancy and then applied experimental heating treatments, based on current seasonal temperatures and those occurring during fires, to seeds of all study species. Additionally, higher seasonal temperature treatments were applied to assess response of seeds to temperatures projected under future climate scenarios. Levels of germination response and mortality were determined to assess how tightly germination response was bound to either fire or seasonal cues. Six species were found to have dormancy cues bound to temperatures that only occur during fires (80°C and above) and were grouped as having obligate pyrogenic dormancy release. The remaining species, classified as having facultative pyrogenic dormancy, had lower temperature dormancy thresholds and committed at least 30% of seeds to germinate after summer-temperature treatments. Evidence from this study supports including dormancy-breaking temperature thresholds as an attribute for identifying functional types. High temperature thresholds for breaking dormancy, found in our obligate pyrogenic group, appear to be a fire-adapted trait, while we predict that

  5. Temperature thresholds of physically dormant seeds and plant functional response to fire: variation among species and relative impact of climate change.

    PubMed

    Ooi, Mark K J; Denham, Andrew J; Santana, Victor M; Auld, Tony D

    2014-03-01

    Variation in dormancy thresholds among species is rarely studied but may provide a basis to better understand the mechanisms controlling population persistence. Incorporating dormancy-breaking temperature thresholds into existing trait frameworks could improve predictions regarding seed bank persistence, and subsequently species resilience in response to fire, climate change and anthropogenic management. A key ecological strategy for many species from fire-prone ecosystems is the possession of a long-lived seed bank, ensuring recovery after fire. Physical dormancy is dominant in these ecosystems and maintaining this dormancy is directly linked to seed bank persistence. We identified a suite of seed-related factors relevant to maintaining populations in fire-prone regions for 14 co-occurring physically dormant species. We measured variation in initial levels of dormancy and then applied experimental heating treatments, based on current seasonal temperatures and those occurring during fires, to seeds of all study species. Additionally, higher seasonal temperature treatments were applied to assess response of seeds to temperatures projected under future climate scenarios. Levels of germination response and mortality were determined to assess how tightly germination response was bound to either fire or seasonal cues. Six species were found to have dormancy cues bound to temperatures that only occur during fires (80°C and above) and were grouped as having obligate pyrogenic dormancy release. The remaining species, classified as having facultative pyrogenic dormancy, had lower temperature dormancy thresholds and committed at least 30% of seeds to germinate after summer-temperature treatments. Evidence from this study supports including dormancy-breaking temperature thresholds as an attribute for identifying functional types. High temperature thresholds for breaking dormancy, found in our obligate pyrogenic group, appear to be a fire-adapted trait, while we predict that

  6. Normal birth weight variation and children's neuropsychological functioning: links between language, executive functioning, and theory of mind.

    PubMed

    Wade, M; Browne, D T; Madigan, S; Plamondon, A; Jenkins, J M

    2014-10-01

    The effect of low birth weight on children's development has been documented for a range of neurocognitive outcomes. However, few previous studies have examined the effect of birth weight variability within the normal range on children's neuropsychological development. The current study examined birth weight variation amongst children weighing ≥2500 g in relation to their language, executive functioning (EF), and theory of mind (ToM), and specified a developmental pathway in which birth weight was hypothesized to be associated with children's EF and ToM through their intermediary language skills. The current study used a prospective community birth cohort of 468 children. Families were recruited when children were newborns and followed up every 18 months until children were age 4.5. Language was assessed at age 3 using a standardized measure of receptive vocabulary (PPVT), and EF and ToM were measured at age 4.5 using previously validated and developmentally appropriate tasks. After controlling for potential confounding variables (family income, parent education, gestational age), birth weight within the normal range was associated with language ability at age 3 (β=.17; p=.012); and the effect of birth weight on both EF (z=2.09; p=.03) and ToM (z=2.07; p=.03) at age 4.5 operated indirectly through their language ability at age 3. Our findings indicate that the effects of birth weight on child neurocognition extend into the normal range of birth weight, and specific developmental mechanisms may link these skills over time.

  7. A re-examination of cremains weight: sex and age variation in a Northern California sample.

    PubMed

    Van Deest, Traci L; Murad, Turhon A; Bartelink, Eric J

    2011-03-01

    The reduction of modern commercially cremated remains into a fine powder negates the use of traditional methods of skeletal analysis. The literature on the use of cremains weight for estimating aspects of the biologic profile is limited, often with conflicting results. This study re-evaluates the value of weight in the assessment of biologic parameters from modern cremated remains. A sample of adults was collected in northern California (n = 756), with a cremains weight averaging 2737.1 g. Males were significantly heavier than females (mean = 3233.2 g versus mean = 2238.3 g, respectively; p<0.001). Comparison of this sample with other previously reported samples from southern California, Florida, and Tennessee indicates a consistent sex difference, with the most similar mean values to the Tennessee study. Although cremains weight decreases with age as expected, the relationship is weak; thus, cremains weight cannot accurately predict age-at-death. While sex estimation shows considerable accuracy (86.3% for males and 80.9% for females), sectioning points may be population specific.

  8. A re-examination of cremains weight: sex and age variation in a Northern California sample.

    PubMed

    Van Deest, Traci L; Murad, Turhon A; Bartelink, Eric J

    2011-03-01

    The reduction of modern commercially cremated remains into a fine powder negates the use of traditional methods of skeletal analysis. The literature on the use of cremains weight for estimating aspects of the biologic profile is limited, often with conflicting results. This study re-evaluates the value of weight in the assessment of biologic parameters from modern cremated remains. A sample of adults was collected in northern California (n = 756), with a cremains weight averaging 2737.1 g. Males were significantly heavier than females (mean = 3233.2 g versus mean = 2238.3 g, respectively; p<0.001). Comparison of this sample with other previously reported samples from southern California, Florida, and Tennessee indicates a consistent sex difference, with the most similar mean values to the Tennessee study. Although cremains weight decreases with age as expected, the relationship is weak; thus, cremains weight cannot accurately predict age-at-death. While sex estimation shows considerable accuracy (86.3% for males and 80.9% for females), sectioning points may be population specific. PMID:21265835

  9. Variations in seed protein content of cotton (Gossypium hirsutum L.) mutant lines by in vivo and in vitro mutagenesis.

    PubMed

    Muthusamy, Annamalai; Jayabalan, Narayanasamy

    2013-01-01

    The present work describes the influence of gamma irradiation (GR), ethyl methane sulphonate (EMS) and sodium azide (SA) treatment on yield and protein content of selected mutant lines of cotton. Seeds of MCU 5 and MCU 11 were exposed to gamma rays (GR), ethyl methane sulphonate (EMS) and sodium azide (SA). Lower dose of gamma irradiation (100-500 Gy), 10-50 mM EMS and SA at lower concentration effectively influences in improving the yield and protein content. Significant increase in yield (258.9 g plant(-1)) and protein content (18.63 mg g(-1) d. wt.) as compared to parental lines was noted in M2 generations. During the subsequent field trials, number of mutant lines varied morphologically in terms of yield as well as biochemical characters such as protein. The selected mutant lines were bred true to their characters in M3 and M4 generations. The significant increase in protein content and profiles of the mutant lines with range of 10.21-18.63 mg g(-1). The SDS-PAGE analysis of mutant lines revealed 9 distinct bands of different intensities with range of 26-81 kDa. The difference in intensity of bands was more (41, 50 and 58 kDa) in the mutant lines obtained from in vitro mutation than in vivo mutation. Significance of such stimulation in protein content correlated with yielding ability of the mutant lines of cotton in terms of seed weight per plant. The results confirm that in cotton it is possible to enhance the both yield and biochemical characters by in vivo and in vitro mutagenic treatments.

  10. Variations of Weight of Thyroid Gland in Different Age and Sex Groups of Bangladeshi Cadavers.

    PubMed

    Sultana, R; Khan, M K; Mannan, S; Asaduzzaman, S M; Sultana, M; Sultana, J; Farzana, T; Epsi, E Z; Wahed, F; Sultana, S

    2015-07-01

    A cross sectional descriptive study was designed to find out the difference in weight of the thyroid gland of Bangladeshi people in relation to age and sex. The present study was performed on 70 post mortem human thyroid gland (35 of male and 35 of female) collected from the morgue in the Department of Forensic Medicine, Mymensingh Medical College, Mymensingh by purposive sampling technique. The specimens were collected from Bangladeshi cadavers of age ranging from 10 years to 85 years. All the specimens were grouped into three categories Group A (upto 20 years), Group B (21 to 50 years) and Group C (>50 years) according to age. Dissection was performed according to standard autopsy techniques. The weight of the thyroid glands were measured and recorded. The mean weight of the thyroid gland was 6.94 ± 5.20 gm in Group A, 7.91 ± 5.89 gm in Group B and 10.42 ± 6.27 gm in Group C. The mean weight of the thyroid gland in male was 7.0 ± 5.77 gm in Group A, 9.94 ± 7.63 gm in Group B and 11.89 ± 5.73 gm in Group C and in female was 6.88 ± 4.88 gm in Group A, 5.88 ± 2.15 gm in Group B and 9.10 ± 6.74 gm in Group C. Variance analysis shows that there was no significant difference in mean weight between the Age Group A & B, B & C and C & A. There was significant difference of weight of thyroid gland between sex in age Group B but in Group A and Group C were statistically insignificant. The weight of the thyroid gland was found to increases with age. In statistical analysis, differences between age groups were analyzed by using one way ANOVA test. The present study will help to increase the information pool on the weight of thyroid gland of Bangladeshi people.

  11. Variation in seed viability and dormancy of 17 weed species after 24.7 years of burial: the concept of buried seed safe sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 50-year study at Fairbanks, AK was started in 1984 to determine soil seed longevity of 17 weed species. Seeds were buried in mesh bags 2 and 15 cm deep and were recovered 0.7, 1.7, 2.7, 3.7, 4.7, 6.7, 9.7,19.7 and 24.7 yr later. Viability was determined using germination and tetrazolium tests. By ...

  12. Genetic variations of body weight and GCRV resistance in a random mating population of grass carp

    PubMed Central

    Huang, Rong; Sun, Jiaxian; Luo, Qing; He, Libo; Liao, Lanjie; Li, Yongming; Guo, Fuhua; Zhu, Zuoyan; Wang, Yaping

    2015-01-01

    The grass carp (Ctenopharyngodon idellus) is an important species in freshwater aquaculture both in China and on a global scale. Variety degeneration and frequent diseases have limited the further development of grass carp aquaculture. Thus, new and improved varieties are required. Here, we identified and assessed the body weight and disease resistance in a random mating population of 19 ♀ × 22 ♂ grass carp, which were derived from different water systems. In both the growth experimental group of 10,245 fish and grass carp reovirus (GCRV)-infected group with 10,000 fish, 78 full-sib families were statistically analyzed for body weight and GCRV resistance. The findings showed that body weight traits had low heritability (0.11 ± 0.04, 0.10 ± 0.03 and 0.12 ± 0.05), GCRV resistance traits had high heritability (0.63 ± 0.11); body weight was higher in 3 families, whereas GCRV resistance was significantly greater in 11 families. Our results confirmed that the natural germplasm resources of wild grass carp were genetically diverse. Breeding of GCRV resistant varieties of grass carp have better genetic basis. This study provides the basis for constructing basal populations for grass carp selective breeding, quantitative trait loci (QTL) and genome-wide association studies (GWAS) analysis. PMID:26439690

  13. Child Health in Peru: Importance of Regional Variation and Community Effects on Children's Height and Weight

    ERIC Educational Resources Information Center

    Shin, Heeju

    2007-01-01

    In developing countries, height and weight are good indicators of children's health and nutritional status. Maternal education has been accepted as one of the most important influences on child health. Using the 2000 Demographic and Health Survey of Peru, however, I find that the effect of maternal education varies as a function of region. In the…

  14. Seasonal Variation in Pigeon Body Weight and Delayed Matching-to-Sample Performance

    ERIC Educational Resources Information Center

    Sargisson, Rebecca J.; McLean, Ian G.; Brown, Glenn S.; White, K. Geoffrey

    2007-01-01

    The weights of 5 pigeons with free access to food, monitored over 3 calendar years in the laboratory, were found to fluctuate with season. All pigeons were at their heaviest in the winter and were lightest in the summer. Five different pigeons performed a standard delayed matching-to-sample task for 44 weeks from January to November. Their weights…

  15. Variation in genes related to obesity, weight and weight change and risk of contralateral breast cancer in the WECARE Study population

    PubMed Central

    Brooks, Jennifer D.; Bernstein, Leslie; Teraoka, Sharon N.; Knight, Julia A.; Mellemkjær, Lene; John, Esther M.; Malone, Kathleen E.; Reiner, Anne S.; Lynch, Charles F.; Concannon, Patrick; Haile, Robert W.; Bernstein, Jonine L

    2012-01-01

    Background Body mass index (BMI), a known breast cancer risk factor, could influence breast risk through mechanistic pathways related to sex hormones, insulin resistance, chronic inflammation and altered levels of adipose derived hormones. Results from studies of the relationship between BMI and second primary breast cancer have been mixed. To explore the relationship between BMI and asynchronous contralateral breast cancer (CBC), we examined whether variants in genes related to obesity, weight and weight change are associated with CBC risk. Methods Variants in twenty genes (182 single nucleotide polymorphisms) involved in adipose tissue metabolism, energy balance, insulin resistance and inflammation, as well as those identified through genome-wide association studies of BMI and type II diabetes were evaluated. We examined the association between variants in these genes and the risk of CBC among Caucasian participants (643 cases with CBC and 1,271 controls with unilateral breast cancer) in the population-based Women’s Environmental Cancer and Radiation Epidemiology (WECARE) Study using conditional logistic regression. Results After adjustment for multiple comparisons, no statistically significant associations between any variant and CBC risk were seen. Stratification by menopausal or estrogen receptor status did not alter these findings. Conclusion Among women with early onset disease who survive a first breast cancer diagnosis there was no association between variation in obesity-related genes and risk of CBC. Impact Genetic variants in genes related to obesity are not likely to strongly influence subsequent risk of developing a second primary breast cancer. PMID:23033454

  16. Allelic Variation of BnaC.TT2.a and Its Association with Seed Coat Color and Fatty Acids in Rapeseed (Brassica napus L.)

    PubMed Central

    Hussain, Nazim; Li, Zhilan; Wu, Dezhi; Jiang, Lixi

    2016-01-01

    Efficient molecular markers for the selection of rapeseed genetic materials with high seed oil content and ideal fatty acid (FA) composition are preferred by rapeseed breeders. Recently, we reported the molecular mechanism of TRANSPARENT TESTA 2 (TT2) in inhibiting seed FA biosynthesis in Arabidopsis. However, evidence showing the association of rapeseed TT2 homologs and seed FA production are still insufficient. In this study, we collected 83 rapeseed (Brassica napus L.) landraces from different geographical backgrounds to conduct association mapping of BnaC.TT2.a in relation to seed coat color and FA biosynthesis. Population background was corrected by 84 pairs of SSR markers that were uniformly distributed among the linkage groups of the Tapidor-Ningyou-7 DH population. A single copy of BnaC.TT2.a for single nucleotide polymorphism (SNP) assay was cloned by a pair of previously reported specific primers. From the analysis of BnaC.TT2.a allelic variations using GLM+Q model, four SNPs on intron 1 of BnaC.TT2.a that were associated with seed FA were discovered. Moreover, an InDel at position 738 on exon 3 of BnaC.TT2.a indicated a change of protein function that was significantly associated with seed coat color, linoleic acid (C18:2), and total FA content. These findings revealed the role of BnaC.TT2.a in regulating the seed color formation and seed FA biosynthesis in rapeseed, thereby suggesting effective molecular markers for rapeseed breeding. PMID:26752200

  17. Reproductive habitus, psychosocial health, and birth weight variation in Mexican immigrant and Mexican American women in south Texas.

    PubMed

    Fleuriet, K Jill; Sunil, T S

    2015-08-01

    The Latina Paradox, or persistent, unexplained variation in low birth weight rates in recently immigrated Mexican women and the trend toward higher rates in subsequent generations of Mexican American women, is most often attributed to unidentified sociocultural causes. We suggest herein that different disciplinary approaches can be synthesized under the constructs of reproductive habitus and subjective social status to identify influences of sociocultural processes on birth weight. Reproductive habitus are "modes of living the reproductive body, bodily practices, and the creation of new subjects through interactions between people and structures" (Smith-Oka, 2012: 2276). Subjective social status infers comparison of self to others based on community definitions of status or socioeconomic status (Adler 2007). We present results from a prospective study of low-income Mexican immigrant and Mexican American women from south Texas that tested the ability of reproductive habitus and subjective social status to elucidate the Latina Paradox. We hypothesized that reproductive habitus between Mexican immigrant women and Mexican American women inform different subjective social statuses during pregnancy, and different subjective social statuses mediate responses to psychosocial stressors known to correlate with low birth weight. Six hundred thirty-one women were surveyed for psychosocial health, subjective social status, and reproductive histories between 2011 and 2013. Eighty-three women were interviewed between 2012 and 2013 for status during pregnancy, prenatal care practices, and pregnancy narratives and associations. Birth weight was extracted from medical records. Results were mixed. Subjective social status and pregnancy-related anxiety predicted low birth weight in Mexican immigrant but not Mexican American women. Mexican immigrant women had significantly lower subjective social status scores but a distinct reproductive habitus that could explain improved psychosocial

  18. Reproductive habitus, psychosocial health, and birth weight variation in Mexican immigrant and Mexican American women in south Texas.

    PubMed

    Fleuriet, K Jill; Sunil, T S

    2015-08-01

    The Latina Paradox, or persistent, unexplained variation in low birth weight rates in recently immigrated Mexican women and the trend toward higher rates in subsequent generations of Mexican American women, is most often attributed to unidentified sociocultural causes. We suggest herein that different disciplinary approaches can be synthesized under the constructs of reproductive habitus and subjective social status to identify influences of sociocultural processes on birth weight. Reproductive habitus are "modes of living the reproductive body, bodily practices, and the creation of new subjects through interactions between people and structures" (Smith-Oka, 2012: 2276). Subjective social status infers comparison of self to others based on community definitions of status or socioeconomic status (Adler 2007). We present results from a prospective study of low-income Mexican immigrant and Mexican American women from south Texas that tested the ability of reproductive habitus and subjective social status to elucidate the Latina Paradox. We hypothesized that reproductive habitus between Mexican immigrant women and Mexican American women inform different subjective social statuses during pregnancy, and different subjective social statuses mediate responses to psychosocial stressors known to correlate with low birth weight. Six hundred thirty-one women were surveyed for psychosocial health, subjective social status, and reproductive histories between 2011 and 2013. Eighty-three women were interviewed between 2012 and 2013 for status during pregnancy, prenatal care practices, and pregnancy narratives and associations. Birth weight was extracted from medical records. Results were mixed. Subjective social status and pregnancy-related anxiety predicted low birth weight in Mexican immigrant but not Mexican American women. Mexican immigrant women had significantly lower subjective social status scores but a distinct reproductive habitus that could explain improved psychosocial

  19. a Study on Variations of Shoreline Changes and Temporal-Spatial Potentiality for Cloud Seeding at Urumia Lake

    NASA Astrophysics Data System (ADS)

    Agha Taher, R.; Jafari, M.; Fallah, M.; Alavi, A.

    2015-12-01

    time period has been used. In order to reach better results, images from MODIS satellite has been used as auxiliary data for the images that are with an error margin. Initial classification on the images was conducted to distinguish water and non water applications. Neural network classification was applied with specific scales on the images and the two major applications were thereby extracted. Then, in order to authenticate the proceedings, Error matrix and Kappa coefficient has been applied on the classified images. Base pixel method of neural network was used for the purpose of information extraction while authenticity of that was evaluated too. The outcomes display the trend of Urmia shoreline has been approximately constant between the years of 1976 to 1995 and has experienced very low variations. In 1998 the lake experienced increase of water and therefore advancement of the shoreline of the lake due to increase of precipitation and the volume of inflowing water to the basin. During 2000 to 20125, however, the lake's shoreline has experienced a downward trend, which was intensified in 2007 and reached to its most critical level ever since, that is decreasing to about one third. Further, temporal and spatial potentiality evaluation of clouds seeding in Urmia lake zone has been studied as a solution for improvement and recovery of the current status of the lake, and an algorithm was proposed for optimized temporal- spatial study on could seeding. Ecological, meteorological and synoptic data were used for timing study of the cloud's seeding plan, which upon study; it is easy to evaluate precipitation potential and quality of the system. At the next step, the rate of humidity and also stability of the precipitating system can be analyzed using radar acquired data. Whereas extracted date from MODIS images are expressing the spatial position, therefore in order to study the location of the cloud's seeding, MODIS images of the selected time intervals along with

  20. Strong correlation effects on the d-wave superconductor- spectral weight analysis by variational wave functions

    NASA Astrophysics Data System (ADS)

    Chou, Chung-Pin; Lee, T. K.; Ho, Chang-Ming

    2009-03-01

    We examine the strong correlation effects of the d-wave superconducting state by including the Gutzwiller projection for no electron double occupancy at each lattice site. The spectral weights (SW's) for adding and removing an electon on the projected superconducting state, the ground state of the 2-dimensional t-t'-t"-J model with moderate doped holes describing the high Tc cuprates, are studied numerically on finite lattices and compared with the observation made by low-temperature tunneling (particle asymmetry of tunneling conductance) and angle-resolved photoemission (SW transfer from the projected Fermi liquid tate) spectoscopies. The contast with the dwave case without projection is alo presented.

  1. Child health in Peru: importance of regional variation and community effects on children's height and weight.

    PubMed

    Shin, Heeju

    2007-12-01

    In developing countries, height and weight are good indicators of children's health and nutritional status. Maternal education has been accepted as one of the most important influences on child health. Using the 2000 Demographic and Health Survey of Peru, however, I find that the effect of maternal education varies as a function of region. In the most prosperous urban region, maternal education is less important for child health than in poor rural areas, and a higher level of education has a greater effect in rural areas. Multilevel analysis shows that a significant part of the observed correlation between maternal education and child health is moderated by regional differences and community characteristics. The finding suggests that Peruvian public policy should emphasize resource redistribution as well as women's education, and that investment in maternal education should be considered within regional contexts to enhance child health in rural areas. PMID:18198688

  2. Natural Variation in the Degree of Autonomous Endosperm Formation Reveals Independence and Constraints of Embryo Growth During Seed Development in Arabidopsis thaliana

    PubMed Central

    Ungru, Alexander; Nowack, Moritz K.; Reymond, Matthieu; Shirzadi, Reza; Kumar, Manoj; Biewers, Sandra; Grini, Paul E.; Schnittger, Arp

    2008-01-01

    Seed development in flowering plants is a paradigm for the coordination of different tissues during organ growth. It requires a tight interplay between the two typically sexually produced structures: the embryo, developing from the fertilized egg cell, and the endosperm, originating from a fertilized central cell, along with the surrounding maternal tissues. Little is known about the presumptive signal transduction pathways administering and coordinating these different tissues during seed growth and development. Recently, a new signal has been identified emanating from the fertilization of the egg cell that triggers central cell proliferation without prior fertilization. Here, we demonstrate that there exists a large natural genetic variation with respect to the outcome of this signaling process in the model plant Arabidopsis thaliana. By using a recombinant inbred line population between the two Arabidopsis accessions Bayreuth-0 and Shahdara, we have identified two genetic components that influence the development of unfertilized endosperm. Exploiting this natural variation, we could further dissect the interdependence of embryo and endosperm growth during early seed development. Our data show an unexpectedly large degree of independence in embryo growth, but also reveal the embryo's developmental restrictions with respect to endosperm size. This work provides a genetic framework for dissection of the interplay between embryo and endosperm during seed growth in plants. PMID:18505878

  3. Fast T2-weighted MR imaging: impact of variation in pulse sequence parameters on image quality and artifacts.

    PubMed

    Li, Tao; Mirowitz, Scott A

    2003-09-01

    The purpose of this study was to quantitatively evaluate in a phantom model the practical impact of alteration of key imaging parameters on image quality and artifacts for the most commonly used fast T(2)-weighted MR sequences. These include fast spin-echo (FSE), single shot fast spin-echo (SSFSE), and spin-echo echo-planar imaging (EPI) pulse sequences. We developed a composite phantom with different T1 and T2 values, which was evaluated while stationary as well as during periodic motion. Experiments involved controlled variations in key parameters including effective TE, TR, echo spacing (ESP), receive bandwidth (BW), echo train length (ETL), and shot number (SN). Quantitative analysis consisted of signal-to-noise ratio (SNR), image nonuniformity, full-width-at-half-maximum (i.e., blurring or geometric distortion) and ghosting ratio. Among the fast T(2)-weighted sequences, EPI was most sensitive to alterations in imaging parameters. Among imaging parameters that we tested, effective TE, ETL, and shot number most prominently affected image quality and artifacts. Short T(2) objects were more sensitive to alterations in imaging parameters in terms of image quality and artifacts. Optimal clinical application of these fast T(2)-weighted imaging pulse sequences requires careful attention to selection of imaging parameters.

  4. SIRT1 Polymorphisms Associate with Seasonal Weight Variation, Depressive Disorders, and Diastolic Blood Pressure in the General Population.

    PubMed

    Kovanen, Leena; Donner, Kati; Partonen, Timo

    2015-01-01

    SIRT1 polymorphisms have previously been associated with depressive and anxiety disorders. We aimed at confirming these earlier findings and extending the analyses to seasonal variations in mood and behavior. Three tag single-nucleotide polymorphisms (SNPs) were selected to capture the common variation in the SIRT1 gene. 5910 individuals (with blood sample, diagnostic interview, self-report of on seasonal changes in mood and behavior) were selected from a representative Finnish nationwide population-based sample. Logistic and linear regression models were used to analyze the associations between the SNPs and depressive and anxiety disorders, metabolic syndrome (EGIR criteria) and its components, and health examination measurements, Homeostasis Model Assessments, and diagnoses of type 2 and type 1 diabetes. SIRT1 rs2273773 showed evidence of association with seasonal variation in weight (C-allele, OR = 0.85, 95% CI = 0.76-0.95, p = 0.005). In addition, our study gave further support for the association of SIRT1 gene with depressive disorders (rs3758391) and diastolic blood pressure (rs2273773).

  5. Penalized weighted least-squares approach for multienergy computed tomography image reconstruction via structure tensor total variation regularization.

    PubMed

    Zeng, Dong; Gao, Yuanyuan; Huang, Jing; Bian, Zhaoying; Zhang, Hua; Lu, Lijun; Ma, Jianhua

    2016-10-01

    Multienergy computed tomography (MECT) allows identifying and differentiating different materials through simultaneous capture of multiple sets of energy-selective data belonging to specific energy windows. However, because sufficient photon counts are not available in each energy window compared with that in the whole energy window, the MECT images reconstructed by the analytical approach often suffer from poor signal-to-noise and strong streak artifacts. To address the particular challenge, this work presents a penalized weighted least-squares (PWLS) scheme by incorporating the new concept of structure tensor total variation (STV) regularization, which is henceforth referred to as 'PWLS-STV' for simplicity. Specifically, the STV regularization is derived by penalizing higher-order derivatives of the desired MECT images. Thus it could provide more robust measures of image variation, which can eliminate the patchy artifacts often observed in total variation (TV) regularization. Subsequently, an alternating optimization algorithm was adopted to minimize the objective function. Extensive experiments with a digital XCAT phantom and meat specimen clearly demonstrate that the present PWLS-STV algorithm can achieve more gains than the existing TV-based algorithms and the conventional filtered backpeojection (FBP) algorithm in terms of both quantitative and visual quality evaluations.

  6. Penalized weighted least-squares approach for multienergy computed tomography image reconstruction via structure tensor total variation regularization.

    PubMed

    Zeng, Dong; Gao, Yuanyuan; Huang, Jing; Bian, Zhaoying; Zhang, Hua; Lu, Lijun; Ma, Jianhua

    2016-10-01

    Multienergy computed tomography (MECT) allows identifying and differentiating different materials through simultaneous capture of multiple sets of energy-selective data belonging to specific energy windows. However, because sufficient photon counts are not available in each energy window compared with that in the whole energy window, the MECT images reconstructed by the analytical approach often suffer from poor signal-to-noise and strong streak artifacts. To address the particular challenge, this work presents a penalized weighted least-squares (PWLS) scheme by incorporating the new concept of structure tensor total variation (STV) regularization, which is henceforth referred to as 'PWLS-STV' for simplicity. Specifically, the STV regularization is derived by penalizing higher-order derivatives of the desired MECT images. Thus it could provide more robust measures of image variation, which can eliminate the patchy artifacts often observed in total variation (TV) regularization. Subsequently, an alternating optimization algorithm was adopted to minimize the objective function. Extensive experiments with a digital XCAT phantom and meat specimen clearly demonstrate that the present PWLS-STV algorithm can achieve more gains than the existing TV-based algorithms and the conventional filtered backpeojection (FBP) algorithm in terms of both quantitative and visual quality evaluations. PMID:27490315

  7. SIRT1 Polymorphisms Associate with Seasonal Weight Variation, Depressive Disorders, and Diastolic Blood Pressure in the General Population

    PubMed Central

    Kovanen, Leena; Donner, Kati; Partonen, Timo

    2015-01-01

    SIRT1 polymorphisms have previously been associated with depressive and anxiety disorders. We aimed at confirming these earlier findings and extending the analyses to seasonal variations in mood and behavior. Three tag single-nucleotide polymorphisms (SNPs) were selected to capture the common variation in the SIRT1 gene. 5910 individuals (with blood sample, diagnostic interview, self-report of on seasonal changes in mood and behavior) were selected from a representative Finnish nationwide population-based sample. Logistic and linear regression models were used to analyze the associations between the SNPs and depressive and anxiety disorders, metabolic syndrome (EGIR criteria) and its components, and health examination measurements, Homeostasis Model Assessments, and diagnoses of type 2 and type 1 diabetes. SIRT1 rs2273773 showed evidence of association with seasonal variation in weight (C-allele, OR = 0.85, 95% CI = 0.76–0.95, p = 0.005). In addition, our study gave further support for the association of SIRT1 gene with depressive disorders (rs3758391) and diastolic blood pressure (rs2273773). PMID:26509718

  8. Emotional Experiences of Obese Women with Adequate Gestational Weight Variation: A Qualitative Study

    PubMed Central

    Faria-Schützer, Débora Bicudo; Surita, Fernanda Garanhani de Castro; Alves, Vera Lucia Pereira; Vieira, Carla Maria; Turato, Egberto Ribeiro

    2015-01-01

    Background As a result of the growth of the obese population, the number of obese women of fertile age has increased in the last few years. Obesity in pregnancy is related to greater levels of anxiety, depression and physical harm. However, pregnancy is an opportune moment for the intervention of health care professionals to address obesity. The objective of this study was to describe how obese pregnant women emotionally experience success in adequate weight control. Methods and Findings Using a qualitative design that seeks to understand content in the field of health, the sample of subjects was deliberated, with thirteen obese pregnant women selected to participate in an individual interview. Data was analysed by inductive content analysis and includes complete transcription of the interviews, re-readings using suspended attention, categorization in discussion topics and the qualitative and inductive analysis of the content. The analysis revealed four categories, three of which show the trajectory of body care that obese women experience during pregnancy: 1) The obese pregnant woman starts to think about her body;2) The challenge of the diet for the obese pregnant woman; 3) The relation of the obese pregnant woman with the team of antenatal professionals. The fourth category reveals the origin of the motivation for the change: 4) The potentializing factors for change: the motivation of the obese woman while pregnant. Conclusions During pregnancy, obese women are more in touch with themselves and with their emotional conflicts. Through the transformations of their bodies, women can start a more refined self-care process and experience of the body-mind unit. The fear for their own and their baby's life, due to the risks posed by obesity, appears to be a great potentializing factor for change. The relationship with the professionals of the health care team plays an important role in the motivational support of the obese pregnant woman. PMID:26529600

  9. The auxin conjugate 1-O-indole-3-acetyl-beta-D-glucose is synthesized in immature legume seeds by IAGlc synthase and may be used for modification of some high molecular weight compounds.

    PubMed

    Jakubowska, Anna; Kowalczyk, Stanislaw

    2004-04-01

    Immature seeds of some dicotyledonous plants contain IAGlc synthase catalysing the synthesis of 1-O-IAGlc. This enzyme activity is comparable with 1-O-IAGlc synthase activity investigated earlier in liquid endosperm of Zea mays. Polyclonal antibodies against maize 1-O-IAGlc synthase cross-react with partially purified 1-O-IAGlc synthase from immature pea and rape seeds. Single immunoreactive bands were observed at a locus corresponding to 45.7 kDa and 43.7 kDa from pea and rape enzyme preparations, respectively, unlike that from the 50 kDa molecular mass of the maize enzyme. It was also observed that some high molecular weight compounds of pea seeds are labelled in vivo by [(14)C] IAA, and unlabelled 1-O-IAGlc inhibits that labelling. In immature pea seeds 43-49.8% of the IAA-modified high molecular weight compounds, obtained after ultracentrifugation, was found in the soluble fraction and 50.1-57% in the insoluble fraction. Ester-linked IAA accounted for about 6-9% and 38-45.6% in soluble and insoluble material, respectively, estimated after hydrolysis in 1 N NaOH. Enzymatic hydrolysis of IAA-labelled high molecular weight compounds gives free IAA and compound(s) corresponding to IAGlc isomers. These results suggest that 1-O-IAGlc synthesized in legume seeds may be used for the modification of some high molecular weight compounds. PMID:14990619

  10. The auxin conjugate 1-O-indole-3-acetyl-beta-D-glucose is synthesized in immature legume seeds by IAGlc synthase and may be used for modification of some high molecular weight compounds.

    PubMed

    Jakubowska, Anna; Kowalczyk, Stanislaw

    2004-04-01

    Immature seeds of some dicotyledonous plants contain IAGlc synthase catalysing the synthesis of 1-O-IAGlc. This enzyme activity is comparable with 1-O-IAGlc synthase activity investigated earlier in liquid endosperm of Zea mays. Polyclonal antibodies against maize 1-O-IAGlc synthase cross-react with partially purified 1-O-IAGlc synthase from immature pea and rape seeds. Single immunoreactive bands were observed at a locus corresponding to 45.7 kDa and 43.7 kDa from pea and rape enzyme preparations, respectively, unlike that from the 50 kDa molecular mass of the maize enzyme. It was also observed that some high molecular weight compounds of pea seeds are labelled in vivo by [(14)C] IAA, and unlabelled 1-O-IAGlc inhibits that labelling. In immature pea seeds 43-49.8% of the IAA-modified high molecular weight compounds, obtained after ultracentrifugation, was found in the soluble fraction and 50.1-57% in the insoluble fraction. Ester-linked IAA accounted for about 6-9% and 38-45.6% in soluble and insoluble material, respectively, estimated after hydrolysis in 1 N NaOH. Enzymatic hydrolysis of IAA-labelled high molecular weight compounds gives free IAA and compound(s) corresponding to IAGlc isomers. These results suggest that 1-O-IAGlc synthesized in legume seeds may be used for the modification of some high molecular weight compounds.

  11. Low Molecular Weight Procyanidins from Grape Seeds Enhance the Impact of 5-Fluorouracil Chemotherapy on Caco-2 Human Colon Cancer Cells

    PubMed Central

    Cheah, Ker Y.; Howarth, Gordon S.; Bindon, Keren A.; Kennedy, James A.; Bastian, Susan E. P.

    2014-01-01

    Objective Grape seed procyanidins (PC) are flavan-3-ol oligomers and polymers known for their biological activity in the gut. Grape seed extract (GSE) have been reported to reduce intestinal injury in a rat model of mucositis. We sought to investigate effects of purified PC fractions differing in mean degree of polymerization (mDP) combined with 5-Fluorouracil (5-FU) chemotherapy on the viability of colon cancer cells (Caco-2). Design SixPC fractions (F1-F6) were isolated from Cabernet Sauvignon seeds at two ripeness stages: pre-veraison unripe (immature) and ripe (mature), utilizing step gradient, low-pressure chromatography on a Sephadex LH-20 resin. Fractions were tested on Caco-2 cells, alone and in combination with 5-FU. Eluted fractions were characterized by phloroglucinolysis and gel permeation chromatography. Cell viability was determined by the 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) (MTT) assay. Results All isolated fractions significantly reduced Caco-2 cell viability compared to the control (P<0.05), but F2 and F3 (mDP 2–6) were the most active fractions (immature F2 = 32% mDP 2.4, F3 = 35% mDP 5.8 and mature F2 = 13% mDP 3.6 and F3 = 17% mDP 5.9; percentage of viable cells remaining) on Caco-2 cells. When combined with 5-FU, immature fractions F1-F3 enhanced the cell toxicity effects of 5-FU by 27–73% (P<0.05). Mature seed PC fractions (F1–F4) significantly enhanced the toxicity of 5-FU by 60–83% against Caco-2 cells (P<0.05). Moreover, some fractions alone were more potent at decreasing viability in Caco-2 cells (P<0.05; immature fractions = 65–68% and mature fractions = 83–87%) compared to 5-FU alone (37%). Conclusions PCs of mDP 2–6 (immature F1-F3 and mature F1 and F4)not only enhanced the impact of 5-FU in killing Caco-2 cells, but also surpassed standard 5-FU chemotherapy as an anti-cancer agent.The bioactivity of PC is therefore attributed primarily to lower molecular weight PCs. PMID

  12. Regional variations in the economic burden attributable to excess weight, physical inactivity and tobacco smoking across British Columbia

    PubMed Central

    Krueger, H.; Koot, J. M.; Rasali, D. P.; Gustin, S. E.; Pennock, M.

    2016-01-01

    Abstract Introduction: Prevalence rates of excess weight, tobacco smoking and physical inactivity vary substantially by geographical region within British Columbia (B.C.). The purpose of this study is to determine the potential reduction in economic burden in B.C. if all regions in the province achieved prevalence rates of these three risk factors equivalent to those of the region with the lowest rates. Methods: We used a previously developed approach based on population-attributable fractions to estimate the economic burden associated with the various risk factors. Sex-specific relative risk and age/sex-specific prevalence data was used in the modelling. Results: The annual economic burden attributable to the three risk factors in B.C. was about $5.6 billion in 2013, with a higher proportion of this total attributable to excess weight ($2.6 billion) than to tobacco smoking ($2.0 billion). While B.C. has lower prevalence rates of the risk factors than any other Canadian province, there is significant variation within the province. If each region in the province were to achieve the best prevalence rates for the three risk factors, then $1.4 billion (24% of the $5.6 billion) in economic burden could be avoided annually. Conclusion: There are notable disparities in the prevalence of each risk factor across health regions within B.C., which were mirrored in each region’s attributable economic burden. A variety of social, environmental and economic factors likely drive some of this geographical variation and these underlying factors should be considered when developing prevention programs. PMID:27077793

  13. Adaptive-weighted total variation minimization for sparse data toward low-dose x-ray computed tomography image reconstruction

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

    2012-12-01

    Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.

  14. Adaptive-weighted total variation minimization for sparse data toward low-dose x-ray computed tomography image reconstruction.

    PubMed

    Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

    2012-12-01

    Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.

  15. Morpho-Physiological Variation of White Spruce Seedlings from Various Seed Sources and Implications for Deployment under Climate Change

    PubMed Central

    Villeneuve, Isabelle; Lamhamedi, Mohammed S.; Benomar, Lahcen; Rainville, André; DeBlois, Josianne; Beaulieu, Jean; Bousquet, Jean; Lambert, Marie-Claude; Margolis, Hank

    2016-01-01

    Because of changes in climatic conditions, tree seeds originating from breeding programs may no longer be suited to sites where they are currently sent. As a consequence, new seed zones may have to be delineated. Assisted migration consists of transferring seed sources that match the future climatic conditions to which they are currently adapted. It represents a strategy that could be used to mitigate the potential negative consequences of climate change on forest productivity. Decisions with regard to the choice of the most appropriate seed sources have to rely on appropriate knowledge of morpho-physiological responses of trees. To meet this goal, white spruce (Picea glauca [Moench] Voss) seedlings from eight seed orchards were evaluated during two years in a forest nursery, and at the end of the first growing season on three plantation sites located in different bioclimatic domains in Quebec. The morpho-physiological responses obtained at the end of the second growing season (2+0) in the nursery made it possible to cluster the orchards into three distinct groups. Modeling growth curves of these different groups showed that the height growth of seedlings from the second-generation and southern first-generation seed orchards was significantly higher than that of those from other orchards, by at least 6%. A multiple regression model with three climatic variables (average growing season temperature, average July temperature, length of the growing season) showed that the final height of seedlings (2+0) from the first-generation seed orchards was significantly related to the local climatic conditions at the orchard sites of origin where parental trees from surrounding natural populations were sampled to provide grafts for orchard establishment. Seedling height growth was significantly affected by both seed source origins and planting sites, but the relative ranking of the different seed sources was maintained regardless of reforestation site. This knowledge could be

  16. Variation in social and sexual behaviour in four species of aposematic seed bugs (Hemiptera: Lygaeidae): the role of toxic and non-toxic food.

    PubMed

    Burdfield-Steel, Emily R; Dougherty, Liam R; Smith, Lynsey A; Collins, Laura A; Shuker, David M

    2013-10-01

    Understanding variation in social behaviour both within and among species continues to be a challenge. Evolutionary or ecological theory typically predicts the optimal behaviour for an animal under a given set of circumstances, yet the real world presents much greater variation in behaviour than predicted. This variation is apparent in many social and sexual interactions, including mate choice, and has led to a renewed focus on individual variation in behaviour. Here we explore within and among species variation in social behaviour in four species of aposematic seed bug (Lygaeidae: Hemiptera). These species are Müllerian mimics, with characteristic warning colouration advertising their chemical toxicity. We examine the role of diet in generating variation in two key behaviours: social aggregation of nymphs and mate choice. We test how behaviour varies with exposure to either milkweed (a source of defensive compounds) or sunflower (that provides no defence). We show that although the four species vary in their food preferences, and diet influences their life-history (as highlighted by body size), social aggregation and mate choice is relatively unaffected by diet. We discuss our findings in terms of the evolution of aposematism, the importance of automimicry, and the role of diet in generating behavioural variation. PMID:23796773

  17. Development of gene-based markers for use in construction of the chickpea (Cicer arietinum L.) genetic linkage map and identification of QTLs associated with seed weight and plant height.

    PubMed

    Gupta, Shefali; Kumar, Tapan; Verma, Subodh; Bharadwaj, Chellapilla; Bhatia, Sabhyata

    2015-11-01

    Seed weight and plant height are important agronomic traits and contribute to seed yield. The objective of this study was to identify QTLs underlying these traits using an intra-specific mapping population of chickpea. A F11 population of 177 recombinant inbred lines derived from a cross between SBD377 (100-seed weight--48 g and plant height--53 cm) and BGD112 (100-seed weight--15 g and plant height--65 cm) was used. A total of 367 novel EST-derived functional markers were developed which included 187 EST-SSRs, 130 potential intron polymorphisms (PIPs) and 50 expressed sequence tag polymorphisms (ESTPs). Along with these, 590 previously published markers including 385 EST-based markers and 205 genomic SSRs were utilized. Of the 957 markers tested for analysis of parental polymorphism between the two parents of the mapping population, 135 (14.64%) were found to be polymorphic. Of these, 131 polymorphic markers could be mapped to the 8 linkage groups. The linkage map had a total length of 1140.54 cM with an average marker density of 8.7 cM. The map was further used for QTL identification using composite interval mapping method (CIM). Two QTLs each for seed weight, qSW-1 and qSW-2 (explaining 11.54 and 19.24% of phenotypic variance, respectively) and plant height, qPH-1 and qPH-2 (explaining 13.98 and 12.17% of phenotypic variance, respectively) were detected. The novel set of genic markers, the intra-specific linkage map and the QTLs identified in the present study will serve as valuable genomic resources in improving the chickpea seed yield using marker-assisted selection (MAS) strategies.

  18. Toxicity of combined chromium(VI) and phenanthrene pollution on the seed germination, stem lengths, and fresh weights of higher plants.

    PubMed

    Hu, Shuangqing; Gu, Hairong; Cui, Chunyan; Ji, Rong

    2016-08-01

    Studies of the interaction and toxicity of pollutant combinations such as heavy metals and PAHs are of practical importance in the remediation and monitoring of the industrial soil environment. This study investigated the single and combined toxicity of chromium(VI) and phenanthrene on three important higher plants: mung beans (Phaseolus aureus), pakchoi cabbage (Brassica chinensis), and rice (Oryza sativa). In experiments using artificial soil matrix, the EC10 and EC20 of the two pollutants, alone and in combination, were analyzed with respect to seed germination, stem length, and above-ground fresh weight of these higher plants. The additive index method was used to evaluate the combined biological toxicity of chromium(VI) and phenanthrene. The results showed that the EC20 of chromium(VI) on the stem lengths of mung beans, pakchoi cabbage, and rice was 289, 248, and 550 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 334, 307, and 551 mg kg(-1). The EC20 of phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 528, 426, and 628 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 696, 585, and 768 mg kg(-1). The EC20 of a combination of chromium(VI) and phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 192, 173, and 279 mg kg(-1), respectively, and 200, 205, and 271 mg kg(-1) for the fresh weights of the three plants. The single and combined exposure of soil to chromium(VI) and phenanthrene had deleterious effects on plants in the early stage of growth. Overall, pakchoi cabbage was more sensitive than mung beans and rice. The two pollutants exerted synergistic effects on the stem lengths and above-ground fresh weights of both mung beans and rice but antagonistic effects on pakchoi cabbage. The results of this study also suggested pakchoi cabbage as a sensitive indicator of soil pollution.

  19. Toxicity of combined chromium(VI) and phenanthrene pollution on the seed germination, stem lengths, and fresh weights of higher plants.

    PubMed

    Hu, Shuangqing; Gu, Hairong; Cui, Chunyan; Ji, Rong

    2016-08-01

    Studies of the interaction and toxicity of pollutant combinations such as heavy metals and PAHs are of practical importance in the remediation and monitoring of the industrial soil environment. This study investigated the single and combined toxicity of chromium(VI) and phenanthrene on three important higher plants: mung beans (Phaseolus aureus), pakchoi cabbage (Brassica chinensis), and rice (Oryza sativa). In experiments using artificial soil matrix, the EC10 and EC20 of the two pollutants, alone and in combination, were analyzed with respect to seed germination, stem length, and above-ground fresh weight of these higher plants. The additive index method was used to evaluate the combined biological toxicity of chromium(VI) and phenanthrene. The results showed that the EC20 of chromium(VI) on the stem lengths of mung beans, pakchoi cabbage, and rice was 289, 248, and 550 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 334, 307, and 551 mg kg(-1). The EC20 of phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 528, 426, and 628 mg kg(-1), respectively. The corresponding EC20 values for the fresh weights of the three plants were 696, 585, and 768 mg kg(-1). The EC20 of a combination of chromium(VI) and phenanthrene on the stem lengths of mung beans, pakchoi cabbage, and rice was 192, 173, and 279 mg kg(-1), respectively, and 200, 205, and 271 mg kg(-1) for the fresh weights of the three plants. The single and combined exposure of soil to chromium(VI) and phenanthrene had deleterious effects on plants in the early stage of growth. Overall, pakchoi cabbage was more sensitive than mung beans and rice. The two pollutants exerted synergistic effects on the stem lengths and above-ground fresh weights of both mung beans and rice but antagonistic effects on pakchoi cabbage. The results of this study also suggested pakchoi cabbage as a sensitive indicator of soil pollution. PMID

  20. Male fertility versus sterility, cytotype, and DNA quantitative variation in seed production in diploid and tetraploid sea lavenders (Limonium sp., Plumbaginaceae) reveal diversity in reproduction modes.

    PubMed

    Róis, Ana Sofia; Teixeira, Generosa; Sharbel, Timothy F; Fuchs, Jörg; Martins, Sérgio; Espírito-Santo, Dalila; Caperta, Ana D

    2012-12-01

    were present in each seed. Flow cytometric seed screens using such mature seeds showed quantitative variations in seeds ploidy level. It is concluded that male function seems to play an important role in the reproduction modes of Limonium diploids and tetraploids.

  1. Within-population spatial variation in pollinator visitation rates, pollen limitation on seed set, and flower longevity in an alpine species

    NASA Astrophysics Data System (ADS)

    Lundemo, Sverre; Totland, Ørjan

    2007-11-01

    Pollen limitation through insufficient pollen deposition on stigmas caused by too infrequent pollinator visitation may influence the reproductive outcome of plants. In this study we investigated how pollinator visitation rate, the degree of pollen limitation, and flower longevity varied spatially among three sites at different altitudes within a population of the dwarf shrub Dryas octopetala L. in alpine southern Norway. Significant pollen limitation on seed set only occurred at the mid-elevation site, while seed set at the other sites appeared to be mainly resource limited, thus indicating a spatial variation in pollen limitation. There was no association between the spatial variation in the extent of pollen limitation and pollinator visitation rate to flowers. However, pollinator visitation rates were related to flower longevity of Dryas; sites with low visitation rates had long-lived flowers and vice versa. Thus, our results suggest within-population spatial co-variation between pollinator visitation rates, pollen limitation, and a developmental response to these factors, flower longevity.

  2. Identification, expression and variation of the GNPDA2 gene, and its association with body weight and fatness traits in chicken.

    PubMed

    Ouyang, Hongjia; Zhang, Huan; Li, Weimin; Liang, Sisi; Jebessa, Endashaw; Abdalla, Bahareldin A; Nie, Qinghua

    2016-01-01

    Background. The GNPDA2 (glucosamine-6-phosphate deaminase 2) gene is a member of Glucosamine-6-phosphate (GlcN6P) deaminase subfamily, which encoded an allosteric enzyme of GlcN6P. Genome-wide association studies (GWAS) have shown that variations of human GNPDA2 are associated with body mass index and obesity risk, but its function and metabolic implications remain to be elucidated.The object of this study was to characterize the gene structure, expression, and biological functions of GNPDA2 in chickens. Methods. Variant transcripts of chicken GNPDA2 and their expression were investigated using rapid amplification of cDNA ends (RACE) system and real-time quantitative PCR technology. We detected the GNPDA2 expression in hypothalamic, adipose, and liver tissue of Xinghua chickens with fasting and high-glucose-fat diet treatments, and performed association analysis of variations of GNPDA2 with productive traits in chicken. The function of GNPDA2 was further studied by overexpression and small interfering RNA (siRNA) methods in chicken preadipocytes. Results.Four chicken GNPDA2 transcripts (cGNPDA2-a∼cGNPDA2-d) were identified in this study. The complete transcript GNPDA2-a was predominantly expressed in adipose tissue (subcutaneous fat and abdominal fat), hypothalamus, and duodenum. In fasting chickens, the mRNA level of GNPDA2 was decreased by 58.8% (P < 0.05) in hypothalamus, and returned to normal level after refeeding. Chicken fed a high-glucose-fat diet increased GNPDA2 gene expression about 2-fold higher in adipose tissue (P < 0.05) than that in the control (fed a basal diet), but decreased its expression in hypothalamus. Two single-nucleotide polymorphisms of the GNPDA2 gene were significantly associated with body weight and a number of fatness traits in chicken (P < 0.05). Conclusion. Our findings indicated that the GNPDA2 gene has a potential role in the regulation of body weight, fat and energy metabolism in chickens. PMID:27326383

  3. Identification, expression and variation of the GNPDA2 gene, and its association with body weight and fatness traits in chicken

    PubMed Central

    Ouyang, Hongjia; Zhang, Huan; Li, Weimin; Liang, Sisi; Jebessa, Endashaw; Abdalla, Bahareldin A.

    2016-01-01

    Background. The GNPDA2 (glucosamine-6-phosphate deaminase 2) gene is a member of Glucosamine-6-phosphate (GlcN6P) deaminase subfamily, which encoded an allosteric enzyme of GlcN6P. Genome-wide association studies (GWAS) have shown that variations of human GNPDA2 are associated with body mass index and obesity risk, but its function and metabolic implications remain to be elucidated.The object of this study was to characterize the gene structure, expression, and biological functions of GNPDA2 in chickens. Methods. Variant transcripts of chicken GNPDA2 and their expression were investigated using rapid amplification of cDNA ends (RACE) system and real-time quantitative PCR technology. We detected the GNPDA2 expression in hypothalamic, adipose, and liver tissue of Xinghua chickens with fasting and high-glucose-fat diet treatments, and performed association analysis of variations of GNPDA2 with productive traits in chicken. The function of GNPDA2 was further studied by overexpression and small interfering RNA (siRNA) methods in chicken preadipocytes. Results.Four chicken GNPDA2 transcripts (cGNPDA2-a∼cGNPDA2-d) were identified in this study. The complete transcript GNPDA2-a was predominantly expressed in adipose tissue (subcutaneous fat and abdominal fat), hypothalamus, and duodenum. In fasting chickens, the mRNA level of GNPDA2 was decreased by 58.8% (P < 0.05) in hypothalamus, and returned to normal level after refeeding. Chicken fed a high-glucose-fat diet increased GNPDA2 gene expression about 2-fold higher in adipose tissue (P < 0.05) than that in the control (fed a basal diet), but decreased its expression in hypothalamus. Two single-nucleotide polymorphisms of the GNPDA2 gene were significantly associated with body weight and a number of fatness traits in chicken (P < 0.05). Conclusion. Our findings indicated that the GNPDA2 gene has a potential role in the regulation of body weight, fat and energy metabolism in chickens. PMID:27326383

  4. Modelling long-term fire occurrence factors in Spain by accounting for local variations with geographically weighted regression

    NASA Astrophysics Data System (ADS)

    Martínez-Fernández, J.; Chuvieco, E.; Koutsias, N.

    2013-02-01

    Humans are responsible for most forest fires in Europe, but anthropogenic factors behind these events are still poorly understood. We tried to identify the driving factors of human-caused fire occurrence in Spain by applying two different statistical approaches. Firstly, assuming stationary processes for the whole country, we created models based on multiple linear regression and binary logistic regression to find factors associated with fire density and fire presence, respectively. Secondly, we used geographically weighted regression (GWR) to better understand and explore the local and regional variations of those factors behind human-caused fire occurrence. The number of human-caused fires occurring within a 25-yr period (1983-2007) was computed for each of the 7638 Spanish mainland municipalities, creating a binary variable (fire/no fire) to develop logistic models, and a continuous variable (fire density) to build standard linear regression models. A total of 383 657 fires were registered in the study dataset. The binary logistic model, which estimates the probability of having/not having a fire, successfully classified 76.4% of the total observations, while the ordinary least squares (OLS) regression model explained 53% of the variation of the fire density patterns (adjusted R2 = 0.53). Both approaches confirmed, in addition to forest and climatic variables, the importance of variables related with agrarian activities, land abandonment, rural population exodus and developmental processes as underlying factors of fire occurrence. For the GWR approach, the explanatory power of the GW linear model for fire density using an adaptive bandwidth increased from 53% to 67%, while for the GW logistic model the correctly classified observations improved only slightly, from 76.4% to 78.4%, but significantly according to the corrected Akaike Information Criterion (AICc), from 3451.19 to 3321.19. The results from GWR indicated a significant spatial variation in the local

  5. Orthodoxy, recalcitrance and in-between: describing variation in seed storage characteristics using threshold responses to water loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tolerance of desiccation is typically described by a threshold or low-water-content-limit to survival. This convention provides fairly good distinction between orthodox and recalcitrant seeds, which show thresholds of less than about 0.07 and greater than about 0.2 g H2O g dw-1, respectively. Thresh...

  6. Integration of experiments across diverse environments identifies the genetic determinants of variation in Sorghum bicolor seed element composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing the bioavailable elemental nutrient content in the edible portions of the crop has the potential to increase the value of sorghum for human and animal nutrition. Seedling establishment and seed nutritional quality are in part determined by the sequestration of sufficient mineral nutrients...

  7. Powder flow studies III: tensile strength, consolidation ratio, flow rate, and capsule-filling-weight variation relationships.

    PubMed

    Chowhan, Z T; Yang, I C

    1981-08-01

    The tensile strength of consolidated powder beds was studied by applying a series of loads to the surface of the powder beds in a tensile tester. The results were plotted as tensile strength versus consolidation pressure. The linearity of these plots suggests a direct relationship between tensile strength and consolidation pressure. The following plots gave linear relationships: (1) tensile strength versus consolidation ratio, (b) tensile strength versus coefficient of variation of the filled weight of the capsules, and (c) logarithm of the tensile strength versus logarithm of the flow rate. These results suggest a direct relationship between tensile strength and consolidation ratio and their usefulness in studying powder flow. The physical significance of the empirical equation used in consolidation studies was explored. A comparison of the empirical equation with a theoretically derived equation, under certain assumptions, suggests that the consolidation ratio is a function of the ratio of the initial volume to the net volume and a function of the coefficient of Rankine. The coefficient of Rankine is a function of the angle of internal friction in the static powder bed.

  8. LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

    NASA Astrophysics Data System (ADS)

    Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

    2010-06-01

    This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29-83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.

  9. The seed nuclear proteome

    PubMed Central

    Repetto, Ombretta; Rogniaux, Hélène; Larré, Colette; Thompson, Richard; Gallardo, Karine

    2012-01-01

    Understanding the regulatory networks coordinating seed development will help to manipulate seed traits, such as protein content and seed weight, in order to increase yield and seed nutritional value of important food crops, such as legumes. Because of the cardinal role of the nucleus in gene expression, sub-proteome analyses of nuclei from developing seeds were conducted, taking advantage of the sequences available for model species. In this review, we discuss the strategies used to separate and identify the nuclear proteins at a stage when the seed is preparing for reserve accumulation. We present how these data provide an insight into the complexity and distinctive features of the seed nuclear proteome. We discuss the presence of chromatin-modifying enzymes and proteins that have roles in RNA-directed DNA methylation and which may be involved in modifying genome architecture in preparation for seed filling. Specific features of the seed nuclei at the transition between the stage of cell divisions and that of cell expansion and reserve deposition are described here which may help to manipulate seed quality traits, such as seed weight. PMID:23267364

  10. Genome-wide association and regional heritability mapping to identify loci underlying variation in nematode resistance and body weight in Scottish Blackface lambs.

    PubMed

    Riggio, V; Matika, O; Pong-Wong, R; Stear, M J; Bishop, S C

    2013-05-01

    The genetic architecture underlying nematode resistance and body weight in Blackface lambs was evaluated comparing genome-wide association (GWA) and regional heritability mapping (RHM) approaches. The traits analysed were faecal egg count (FEC) and immunoglobulin A activity against third-stage larvae from Teladorsagia circumcincta, as indicators of nematode resistance, and body weight in a population of 752 Scottish Blackface lambs, genotyped with the 50k single-nucleotide polymorphism (SNP) chip. FEC for both Nematodirus and Strongyles nematodes (excluding Nematodirus), as well as body weight were collected at approximately 16, 20 and 24 weeks of age. In addition, a weighted average animal effect was estimated for both FEC and body weight traits. After quality control, 44 388 SNPs were available for the GWA analysis and 42 841 for the RHM, which utilises only mapped SNPs. The same fixed effects were used in both analyses: sex, year, management group, litter size and age of dam, with day of birth as covariate. Some genomic regions of interest for both nematode resistance and body weight traits were identified, using both GWA and RHM approaches. For both methods, strong evidence for association was found on chromosome 14 for Nematodirus average animal effect, chromosome 6 for Strongyles FEC at 16 weeks and chromosome 6 for body weight at 16 weeks. Across the entire data set, RHM identified more regions reaching the suggestive level than GWA, suggesting that RHM is capable of capturing some of the variation not detected by GWA analyses.

  11. Spatio-Temporal Variation in Contrasting Effects of Resident Vegetation on Establishment, Growth and Reproduction of Dry Grassland Plants: Implications for Seed Addition Experiments

    PubMed Central

    Knappová, Jana; Knapp, Michal; Münzbergová, Zuzana

    2013-01-01

    Successful establishment of plants is limited by both biotic and abiotic conditions and their interactions. Seedling establishment is also used as a direct measure of habitat suitability, but transient changes in vegetation might provide windows of opportunity allowing plant species to colonize sites which otherwise appear unsuitable. We aimed to study spatio-temporal variability in the effects of resident vegetation on establishment, growth and reproduction of dry grassland species in abandoned arable fields representing potentially suitable habitats. Seeds were sown in disturbed (bare of vegetation and roots) and undisturbed plots in three fields abandoned in the last 20 years. To assess the effects of temporal variation on plant establishment, we initiated our experiments in two years (2007 and 2008). Seventeen out of the 35 sown species flowered within two years after sowing, while three species completely failed to become established. The vegetation in the undisturbed plots facilitated seedling establishment only in the year with low spring precipitation, and the effect did not hold for all species. In contrast, growth and flowering rate were consistently much greater in the disturbed plots, but the effect size differed between the fields and years of sowing. We show that colonization is more successful when site opening by disturbance coincide with other suitable conditions such as weather or soil characteristics. Seasonal variability involved in our study emphasizes the necessity of temporal replication of sowing experiments. Studies assessing habitat suitability by seed sowing should either involve both vegetation removal treatments and untreated plots or follow the gradient of vegetation cover. We strongly recommend following the numbers of established individuals, their sizes and reproductive success when assessing habitat suitability by seed sowing since one can gain completely different results in different phases of plant life cycle. PMID:23755288

  12. Spatio-temporal variation in contrasting effects of resident vegetation on establishment, growth and reproduction of dry grassland plants: implications for seed addition experiments.

    PubMed

    Knappová, Jana; Knapp, Michal; Münzbergová, Zuzana

    2013-01-01

    Successful establishment of plants is limited by both biotic and abiotic conditions and their interactions. Seedling establishment is also used as a direct measure of habitat suitability, but transient changes in vegetation might provide windows of opportunity allowing plant species to colonize sites which otherwise appear unsuitable. We aimed to study spatio-temporal variability in the effects of resident vegetation on establishment, growth and reproduction of dry grassland species in abandoned arable fields representing potentially suitable habitats. Seeds were sown in disturbed (bare of vegetation and roots) and undisturbed plots in three fields abandoned in the last 20 years. To assess the effects of temporal variation on plant establishment, we initiated our experiments in two years (2007 and 2008). Seventeen out of the 35 sown species flowered within two years after sowing, while three species completely failed to become established. The vegetation in the undisturbed plots facilitated seedling establishment only in the year with low spring precipitation, and the effect did not hold for all species. In contrast, growth and flowering rate were consistently much greater in the disturbed plots, but the effect size differed between the fields and years of sowing. We show that colonization is more successful when site opening by disturbance coincide with other suitable conditions such as weather or soil characteristics. Seasonal variability involved in our study emphasizes the necessity of temporal replication of sowing experiments. Studies assessing habitat suitability by seed sowing should either involve both vegetation removal treatments and untreated plots or follow the gradient of vegetation cover. We strongly recommend following the numbers of established individuals, their sizes and reproductive success when assessing habitat suitability by seed sowing since one can gain completely different results in different phases of plant life cycle.

  13. Natural Variation in Seed Very Long Chain Fatty Acid Content Is Controlled by a New Isoform of KCS18 in Arabidopsis thaliana

    PubMed Central

    Jasinski, Sophie; Lécureuil, Alain; Miquel, Martine; Loudet, Olivier; Raffaele, Sylvain; Froissard, Marine; Guerche, Philippe

    2012-01-01

    Oil from oleaginous seeds is mainly composed of triacylglycerols. Very long chain fatty acids (VLCFAs) are major constituents of triacylglycerols in many seed oils and represent valuable feedstock for industrial purposes. To identify genetic factors governing natural variability in VLCFA biosynthesis, a quantitative trait loci (QTL) analysis using a recombinant inbred line population derived from a cross between accessions Bay-0 and Shahdara was performed in Arabidopsis thaliana. Two fatty acid chain length ratio (CLR) QTL were identified, with one major locus, CLR.2, accounting for 77% of the observed phenotypic variation. A fine mapping and candidate gene approach showed that a key enzyme of the fatty acid elongation pathway, the β-ketoacyl-CoA synthase 18 (KCS18), was responsible for the CLR.2 QTL detected between Bay-0 and Shahdara. Association genetics and heterologous expression in yeast cells identified a single point mutation associated with an alteration of KCS18 activity, uncovering the molecular bases for the modulation of VLCFA content in these two natural populations of Arabidopsis. Identification of this kcs18 mutant with altered activity opens new perspectives for the modulation of oil composition in crop plants. PMID:23145136

  14. Both Sides Now: Interpreting Beta Weights. "Beta" Weights Should Be Used to Interpret Regression Variates and to Assess In-Context Variable Importance. Cautions and Conditions for Interpreting Weighting Coefficients.

    ERIC Educational Resources Information Center

    Harris, Richard J.; McNeil, Keith

    1993-01-01

    Presents two viewpoints about the use and interpretability of beta weights in educational research: (1) that beta weights should be interpreted as a logical index of the importance of individual predictors within the context of the entire set of predictors; and (2) that interpretation requires certain cautions and conditions. (SV)

  15. A metabonomic study of transgenic maize (Zea mays) seeds revealed variations in osmolytes and branched amino acids.

    PubMed

    Manetti, Cesare; Bianchetti, Cristiano; Casciani, Lorena; Castro, Cecilia; Di Cocco, Maria Enrica; Miccheli, Alfredo; Motto, Mario; Conti, Filippo

    2006-01-01

    The aim of the research was to investigate metabolic variations associated with genetic modifications in the grains of Zea mays using metabonomic techniques. With this in mind, the non-targeted characteristic of the technique is useful to identify metabolites peculiar to the genetic modification and initially undefined. The results obtained showed that the genetic modification, introducing Cry1Ab gene expression, induces metabolic variations involving the primary nitrogen pathway. Concerning the methodological aspects, the experimental protocol used has been applied in this field for the first time. It consists of a combination of partial least square-discriminant analysis and principal component analysis. The most important metabolites for discrimination were selected and the metabolic correlations linking them are identified. Principal component analysis on selected signals confirms metabolic variations, highlighting important details about the changes induced on the metabolic network by the presence of a Bt transgene in the maize genome.

  16. Spatio-Temporal Variation in Length-Weight Relationships and Condition of the Ribbonfish Trichiurus lepturus (Linnaeus, 1758): Implications for Fisheries Management.

    PubMed

    Al Nahdi, Abdullah; Garcia de Leaniz, Carlos; King, Andrew J

    2016-01-01

    Knowledge of length-weight relationships for commercially exploited fish is an important tool for assessing and managing of fish stocks. However, analyses of length-weight relationship fisheries data typically do not consider the inherent differences in length-weight relationships for fish caught from different habitats, seasons, or years, and this can affect the utility of these data for developing condition indices or calculating fisheries biomass. Here, we investigated length-weight relationships for ribbonfish Trichiurus lepturus in the waters of the Arabian Sea off Oman collected during three periods (2001-02, 2007-08, and 2014-15) and showed that a multivariate modelling approach that considers the areas and seasons in which ribbonfish were caught improved estimation of length-weight relationships. We used the outputs of these models to explore spatio-temporal variations in condition indices and relative weights among ribbonfish, revealing fish of 85-125 cm were in the best overall condition. We also found that condition differed according to where and when fish were caught, with condition lowest during spring and pre-south-west monsoon periods and highest during and after the south-west monsoons. We interpret these differences to be a consequence of variability in temperature and food availability. Based on our findings, we suggest fishing during seasons that have the lowest impact on fish condition and which are commercially most viable; such fishery management would enhance fisheries conservation and economic revenue in the region. PMID:27579485

  17. Spatio-Temporal Variation in Length-Weight Relationships and Condition of the Ribbonfish Trichiurus lepturus (Linnaeus, 1758): Implications for Fisheries Management

    PubMed Central

    Garcia de Leaniz, Carlos; King, Andrew J.

    2016-01-01

    Knowledge of length-weight relationships for commercially exploited fish is an important tool for assessing and managing of fish stocks. However, analyses of length-weight relationship fisheries data typically do not consider the inherent differences in length-weight relationships for fish caught from different habitats, seasons, or years, and this can affect the utility of these data for developing condition indices or calculating fisheries biomass. Here, we investigated length-weight relationships for ribbonfish Trichiurus lepturus in the waters of the Arabian Sea off Oman collected during three periods (2001–02, 2007–08, and 2014–15) and showed that a multivariate modelling approach that considers the areas and seasons in which ribbonfish were caught improved estimation of length-weight relationships. We used the outputs of these models to explore spatio-temporal variations in condition indices and relative weights among ribbonfish, revealing fish of 85–125 cm were in the best overall condition. We also found that condition differed according to where and when fish were caught, with condition lowest during spring and pre-south-west monsoon periods and highest during and after the south-west monsoons. We interpret these differences to be a consequence of variability in temperature and food availability. Based on our findings, we suggest fishing during seasons that have the lowest impact on fish condition and which are commercially most viable; such fishery management would enhance fisheries conservation and economic revenue in the region. PMID:27579485

  18. Spatio-Temporal Variation in Length-Weight Relationships and Condition of the Ribbonfish Trichiurus lepturus (Linnaeus, 1758): Implications for Fisheries Management.

    PubMed

    Al Nahdi, Abdullah; Garcia de Leaniz, Carlos; King, Andrew J

    2016-01-01

    Knowledge of length-weight relationships for commercially exploited fish is an important tool for assessing and managing of fish stocks. However, analyses of length-weight relationship fisheries data typically do not consider the inherent differences in length-weight relationships for fish caught from different habitats, seasons, or years, and this can affect the utility of these data for developing condition indices or calculating fisheries biomass. Here, we investigated length-weight relationships for ribbonfish Trichiurus lepturus in the waters of the Arabian Sea off Oman collected during three periods (2001-02, 2007-08, and 2014-15) and showed that a multivariate modelling approach that considers the areas and seasons in which ribbonfish were caught improved estimation of length-weight relationships. We used the outputs of these models to explore spatio-temporal variations in condition indices and relative weights among ribbonfish, revealing fish of 85-125 cm were in the best overall condition. We also found that condition differed according to where and when fish were caught, with condition lowest during spring and pre-south-west monsoon periods and highest during and after the south-west monsoons. We interpret these differences to be a consequence of variability in temperature and food availability. Based on our findings, we suggest fishing during seasons that have the lowest impact on fish condition and which are commercially most viable; such fishery management would enhance fisheries conservation and economic revenue in the region.

  19. Variation at the Melanocortin 4 Receptor gene and response to weight-loss interventions in the Diabetes Prevention Program

    PubMed Central

    Pan, Qing; Delahanty, Linda M.; Jablonski, Kathleen A.; Knowler, William C.; Kahn, Steven E.; Florez, Jose C.; Franks, Paul W.

    2013-01-01

    Objective To assess associations and genotype × treatment interactions for melanocortin 4 receptor (MC4R) locus variants and obesity-related traits. Design and Methods Diabetes Prevention Program (DPP) participants (N=3,819, of whom 3,356 were genotyped for baseline and 3,234 for longitudinal analyses) were randomized into intensive lifestyle modification (diet, exercise, weight loss), metformin or placebo control. Adiposity was assessed in a subgroup (n=909) using computed tomography. All analyses were adjusted for age, sex, ethnicity and treatment. Results The rs1943218 minor allele was nominally associated with short-term (6 month; P=0.032) and long-term (2 year; P=0.038) weight change. Eight SNPs modified response to treatment on short-term (rs17066856, rs9966412, rs17066859, rs8091237, rs17066866, rs7240064) or long-term (rs12970134, rs17066866) reduction in body weight, or diabetes incidence (rs17066829) (all Pinteraction <0.05). Conclusion This is the first study to comprehensively assess the role of MC4R variants and weight regulation in a weight loss intervention trial. One MC4R variant was directly associated with obesity-related traits or diabetes; numerous other variants appear to influence body weight and diabetes risk by modifying the protective effects of the DPP interventions. PMID:23512951

  20. Consumption of diets containing raw soya beans (Glycine max), kidney beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) or lupin seeds (Lupinus angustifolius) by rats for up to 700 days: effects on body composition and organ weights.

    PubMed

    Grant, G; Dorward, P M; Buchan, W C; Armour, J C; Pusztai, A

    1995-01-01

    Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of diets based on raw cowpeas (Vigna unguiculata; moderate Bowman-Birk inhibitor content, low lectin content), lupin seeds (Lupinus angustifolius; low lectin and protease inhibitor content) or soya beans (Glycine max; high Kunitz inhibitor content, moderate Bowman-Birk inhibitor content, moderate lectin content) or diets containing low levels of raw kidney bean (Phaseolus vulgaris; high lectin content, low Bowman-Birk inhibitor content) on body weight and composition and organ weights. All the legume-based diets reduced feed conversion efficiency and growth rates during the initial 250 d. However, after 250 d the weight gains by rats given legume-based diets were similar to those of controls given the same daily feed intake. Long-term consumption of diets containing low levels of kidney bean significantly altered body composition of rats. The levels of lipid in the body were significantly reduced. As a result, carcasses of these rats contained a higher proportion of muscle/protein than did controls. Small-intestine relative weight was increased by short- and long-term consumption of the kidney-bean-based diet. However, the increase in relative pancreatic weight observed at 30 d did not persist long term. None of the other legume-based diets caused any significant changes in body composition. However, long-term exposure to a soya-bean- or cowpea-based diet induced an extensive increase in the relative and absolute weights of the pancreas and caused an increase in the incidence of macroscopic pancreatic nodules and possibly pancreatic neoplasia. Long-term consumption of the cowpea-, kidney-bean-, lupin-seed- or soya-bean-based diets by rats resulted in a significant increase in the relative weight of the caecum and colon.

  1. Consumption of diets containing raw soya beans (Glycine max), kidney beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) or lupin seeds (Lupinus angustifolius) by rats for up to 700 days: effects on body composition and organ weights.

    PubMed

    Grant, G; Dorward, P M; Buchan, W C; Armour, J C; Pusztai, A

    1995-01-01

    Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of diets based on raw cowpeas (Vigna unguiculata; moderate Bowman-Birk inhibitor content, low lectin content), lupin seeds (Lupinus angustifolius; low lectin and protease inhibitor content) or soya beans (Glycine max; high Kunitz inhibitor content, moderate Bowman-Birk inhibitor content, moderate lectin content) or diets containing low levels of raw kidney bean (Phaseolus vulgaris; high lectin content, low Bowman-Birk inhibitor content) on body weight and composition and organ weights. All the legume-based diets reduced feed conversion efficiency and growth rates during the initial 250 d. However, after 250 d the weight gains by rats given legume-based diets were similar to those of controls given the same daily feed intake. Long-term consumption of diets containing low levels of kidney bean significantly altered body composition of rats. The levels of lipid in the body were significantly reduced. As a result, carcasses of these rats contained a higher proportion of muscle/protein than did controls. Small-intestine relative weight was increased by short- and long-term consumption of the kidney-bean-based diet. However, the increase in relative pancreatic weight observed at 30 d did not persist long term. None of the other legume-based diets caused any significant changes in body composition. However, long-term exposure to a soya-bean- or cowpea-based diet induced an extensive increase in the relative and absolute weights of the pancreas and caused an increase in the incidence of macroscopic pancreatic nodules and possibly pancreatic neoplasia. Long-term consumption of the cowpea-, kidney-bean-, lupin-seed- or soya-bean-based diets by rats resulted in a significant increase in the relative weight of the caecum and colon. PMID:7857911

  2. QTL analysis of seed-flooding tolerance in soybean (Glycine max [L.] Merr.).

    PubMed

    Sayama, Takashi; Nakazaki, Tetsuya; Ishikawa, Goro; Yagasaki, Kazuhiro; Yamada, Naohiro; Hirota, Naoko; Hirata, Kaori; Yoshikawa, Takanori; Saito, Hiroki; Teraishi, Masayoshi; Okumoto, Yutaka; Tsukiyama, Takuji; Tanisaka, Takatoshi

    2009-04-01

    In soybean (Glycine max [L.] Merr.), varieties with seed-flooding tolerance at the geminating stage are desirable for breeding in countries with much rainfall at sowing time. Our study revealed great intervarietal variation in seed-flooding tolerance as evaluated by germination rate (GR) and normal seedling rate (NS). Pigmented seed coat and small seed weight tended to give a positive effect on seed-flooding tolerance. Subsequently, QTL analysis of GR and NS were performed and a total of four QTLs were detected. Among them, Sft1 on the linkage group H (LG_H) exhibited a large effect on GR after a 24-h treatment; however, Sft2 near the I locus on LG_A2 involved in seed coat pigmentation exhibited the largest effect on seed-flooding tolerance. Sft1, Sft3 and Sft4 were independent of seed coat color and seed weight. Based on the results, we discussed the physiological effects of genetic factors responsible for seed-flooding tolerance in soybean.

  3. Effect of oxygen content variation on flux pinning in Nd-Ba-Cu-O top-seeded melt grown superconductor

    NASA Astrophysics Data System (ADS)

    Babu, N. Hari; Kambara, M.; Cardwell, D. A.; Campbell, A. M.

    2002-05-01

    The magnetization of top-seeded melt grown NdBa2Cu3O7-δ (Nd123) containing 15 mol% Nd4Ba2Cu2O10 (Nd422) processed in both air and under 1% O2 in N2 has been investigated over a wide range of temperatures and fields. The sample processed in air exhibits a peak in the Jc(H) data in the temperature range 40-70 K, which is similar to that observed in a sample processed under reduced oxygen partial pressure at nearly the same reduced temperature (T/Tc) range. The appearance and position of the peak in the Jc(H) data are governed strongly by the oxygen content. Magnetization as a function of temperature measured under zero field and field-cooled conditions exhibit similar magnetic transition behaviour, despite the large difference in the Nd/Ba substitution level within these samples. Significantly, the basic features of the magnetization curves remain virtually the same when the oxygen content in the sample is varied. Comparison between NdBCO and YBCO superconductors indicates clearly that the defects associated with oxygen vacancies and/or disorder play an important role in flux pinning in both types of melt grown material. The pinning centres in NdBCO observed in this study are similar to those observed in YBCO.

  4. Copy Number Variation of Cytokinin Oxidase Gene Tackx4 Associated with Grain Weight and Chlorophyll Content of Flag Leaf in Common Wheat.

    PubMed

    Chang, Cheng; Lu, Jie; Zhang, Hai-Ping; Ma, Chuan-Xi; Sun, Genlou

    2015-01-01

    As the main pigment in photosynthesis, chlorophyll significantly affects grain filling and grain weight of crop. Cytokinin (CTK) can effectively increase chlorophyll content and chloroplast stability, but it is irreversibly inactivated by cytokinin oxidase (CKX). In this study, therefore, twenty-four pairs of primers were designed to identify variations of wheat CKX (Tackx) genes associated with flag leaf chlorophyll content after anthesis, as well as grain weight in 169 recombinant inbred lines (RIL) derived from Triticum aestivum Jing 411 × Hongmangchun 21. Results indicated variation of Tackx4, identified by primer pair T19-20, was proven to significantly associate with chlorophyll content and grain weight in the RIL population. Here, two Tackx4 patterns were identified: one with two co-segregated fragments (Tackx4-1/Tackx4-2) containing 618 bp and 620 bp in size (as in Jing 411), and another with no PCR product. The two genotypes were designated as genotype-A and genotype-B, respectively. Grain weight and leaf chlorophyll content at 5~15 days after anthesis (DAA) were significantly higher in genotype-A lines than those in genotype-B lines. Mapping analysis indicated Tackx4 was closely linked to Xwmc169 on chromosome 3AL, as well as co-segregated with a major quantitative trait locus (QTL) for both grain weight and chlorophyll content of flag leaf at 5~15 DAA. This QTL explained 8.9~22.3% phenotypic variations of the two traits across four cropping seasons. Among 102 wheat varieties, a third genotype of Tackx4 was found and designated as genotype-C, also having two co-segregated fragments, Tackx4-2 and Tackx4-3 (615bp). The sequences of three fragments, Tackx4-1, Tackx4-2, and Tackx4-3, showed high identity (>98%). Therefore, these fragments could be considered as different copies at Tackx4 locus on chromosome 3AL. The effect of copy number variation (CNV) of Tackx4 was further validated. In general, genotype-A contains both significantly higher grain weight

  5. Copy Number Variation of Cytokinin Oxidase Gene Tackx4 Associated with Grain Weight and Chlorophyll Content of Flag Leaf in Common Wheat

    PubMed Central

    Chang, Cheng; Lu, Jie; Zhang, Hai-Ping; Ma, Chuan-Xi; Sun, Genlou

    2015-01-01

    As the main pigment in photosynthesis, chlorophyll significantly affects grain filling and grain weight of crop. Cytokinin (CTK) can effectively increase chlorophyll content and chloroplast stability, but it is irreversibly inactivated by cytokinin oxidase (CKX). In this study, therefore, twenty-four pairs of primers were designed to identify variations of wheat CKX (Tackx) genes associated with flag leaf chlorophyll content after anthesis, as well as grain weight in 169 recombinant inbred lines (RIL) derived from Triticum aestivum Jing 411 × Hongmangchun 21. Results indicated variation of Tackx4, identified by primer pair T19-20, was proven to significantly associate with chlorophyll content and grain weight in the RIL population. Here, two Tackx4 patterns were identified: one with two co-segregated fragments (Tackx4-1/Tackx4-2) containing 618 bp and 620 bp in size (as in Jing 411), and another with no PCR product. The two genotypes were designated as genotype-A and genotype-B, respectively. Grain weight and leaf chlorophyll content at 5~15 days after anthesis (DAA) were significantly higher in genotype-A lines than those in genotype-B lines. Mapping analysis indicated Tackx4 was closely linked to Xwmc169 on chromosome 3AL, as well as co-segregated with a major quantitative trait locus (QTL) for both grain weight and chlorophyll content of flag leaf at 5~15 DAA. This QTL explained 8.9~22.3% phenotypic variations of the two traits across four cropping seasons. Among 102 wheat varieties, a third genotype of Tackx4 was found and designated as genotype-C, also having two co-segregated fragments, Tackx4-2 and Tackx4-3 (615bp). The sequences of three fragments, Tackx4-1, Tackx4-2, and Tackx4-3, showed high identity (>98%). Therefore, these fragments could be considered as different copies at Tackx4 locus on chromosome 3AL. The effect of copy number variation (CNV) of Tackx4 was further validated. In general, genotype-A contains both significantly higher grain weight

  6. Genetic variation of fasting glucose and changes in glycemia in response to 2-year weight-loss diet intervention: the POUNDS Lost trial

    PubMed Central

    Wang, Tiange; Huang, Tao; Zheng, Yan; Rood, Jennifer; Bray, George A.; Sacks, Frank M.; Qi, Lu

    2016-01-01

    Objective Weight loss intervention through diet modification has been widely used to improve obesity-related hyperglycemia; however, little is known about whether genetic variation modifies the intervention effect. We examined the interaction between weight-loss diets and genetic variation of fasting glucose on changes in glycemic traits in a dietary intervention trial. Research Design and Methods The Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial is a randomized, controlled 2-year weight-loss trial. We assessed overall genetic variation of fasting glucose by calculating a genetic risk score (GRS) based on 14 fasting glucose-associated single nucleotide polymorphisms, and examined the progression in fasting glucose and insulin levels, and insulin resistance and insulin sensitivity in 733 adults from this trial. Results The GRS was associated with 6-month changes in fasting glucose (P<0.001), fasting insulin (P=0.042), homeostasis model assessment of insulin resistance (HOMA-IR, P=0.009) and insulin sensitivity (HOMA-S, P=0.043). We observed significant interaction between the GRS and dietary fat on 6-month changes in fasting glucose, HOMA-IR and HOMA-S after multivariable adjustment (P-interaction=0.007, 0.045, and 0.028, respectively). After further adjustment for weight loss, the interaction remained significant on change in fasting glucose (P=0.015). In the high-fat diet group, participants in the highest GRS tertile showed increased fasting glucose, whereas participants in the lowest tertile showed decreased fasting glucose (P-trend<0.001); in contrast, the genetic association was not significant in the low-fat diet group (P-trend=0.087). Conclusions Our data suggest that participants with a higher genetic risk may benefit more by eating a low-fat diet to improve glucose metabolism. PMID:27113490

  7. Supplementation of dextrose to the diet during the weaning to estrus interval affects subsequent variation in within-litter piglet birth weight.

    PubMed

    Van den Brand, H; Soede, N M; Kemp, B

    2006-02-01

    Effects of supplementation of dextrose to the diet of sows during the weaning-to-estrus interval (WEI) on subsequent litter size and within-litter variation were investigated. After weaning, 223 sows (first to fifth parity) were fed 3.5 kg/d. Half of the sows additionally received 150 g of dextrose per day as topdressing on the feed. WEI and estrus duration were determined as well as subsequent pregnancy rate and litter size. Piglets were weighed individually at birth and at weaning (day 26.4; S.D.: 2.5). Supplementation of dextrose to the diet during the WEI did not affect WEI (106 h), pregnancy rate (88.2%), farrowing rate (84.2%), subsequent litter size (total born: 13.70), or birth weight (1599 g). The within-litter variation in birth weight was lower in sows on the dextrose treatment (CV: 17.5% versus 21.2% for the dextrose and control group, respectively, P=0.03). From this experiment, we concluded that addition of dextrose during the weaning to estrus interval did not increase litter size, but seems to affect the uniformity in birth weight of the litter. PMID:15967602

  8. 7 CFR 201.46 - Weight of working sample.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... a group of kinds of similar size. The weights of the purity and noxious-weed seed working samples in... may be estimated. The weight of the noxious-weed seed working sample shall be determined by... units for the noxious-weed seed examination. (2) Mixtures of coated seed. The working weight shall...

  9. Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

    PubMed

    Pérez, Jesús M; Serrano, Emmanuel; Soriguer, Ramón C; González, Francisco J; Sarasa, Mathieu; Granados, José E; Cano-Manuel, Francisco J; Cuenca, Rafaela; Fandos, Paulino

    2015-01-01

    Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic. PMID:25380360

  10. Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

    PubMed

    Pérez, Jesús M; Serrano, Emmanuel; Soriguer, Ramón C; González, Francisco J; Sarasa, Mathieu; Granados, José E; Cano-Manuel, Francisco J; Cuenca, Rafaela; Fandos, Paulino

    2015-01-01

    Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic.

  11. Incorporating spatial variation in housing attribute prices: a comparison of geographically weighted regression and the spatial expansion method

    NASA Astrophysics Data System (ADS)

    Bitter, Christopher; Mulligan, Gordon F.; Dall'Erba, Sandy

    2007-04-01

    Hedonic house price models typically impose a constant price structure on housing characteristics throughout an entire market area. However, there is increasing evidence that the marginal prices of many important attributes vary over space, especially within large markets. In this paper, we compare two approaches to examine spatial heterogeneity in housing attribute prices within the Tucson, Arizona housing market: the spatial expansion method and geographically weighted regression (GWR). Our results provide strong evidence that the marginal price of key housing characteristics varies over space. GWR outperforms the spatial expansion method in terms of explanatory power and predictive accuracy.

  12. Seed dormancy in Mexican teosinte

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed dormancy in wild Zea species may affect fitness and relate to ecological adaptation. The primary objective of this study was to characterize the variation in seed germination of the wild species of the genus Zea that currently grow in Mexico, and to relate this variation to their ecological zon...

  13. GWR-PM - Spatial variation relationship analysis with Geographically Weighted Regression (GWR) - An application at Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Jamhuri, J.; Azhar, B. M. S.; Puan, C. L.; Norizah, K.

    2016-06-01

    GWR-PM has been developed exclusively for decision makers in Peninsular Malaysia and the purpose is to provide them with additional flexibility in analysing spatial variation. While GWR extension analysis in ArcMap application has a universal coordinate system, GWR-PM is specifically designed with Peninsular Malaysia's coordinate system of Kertau RSO Malaya Meter. This paper presents the development of GWR-PM model by using a model builder, the application of which is to examine the forest fire risk at North Selangor Peat Swamp Forest. This model can be extended and improved by using ArcGIS language of phyton.

  14. Seismic amplitude variation with offset: Its effects on weighted stacking, and its uses in characterization of sandstone and carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Madiba, Gislain Bolouvi

    An algorithm for weighted stacking, which is not particularly expensive in terms of computer time or memory and can be easily incorporated into routine processing is proposed. A comprehensive comparison of the proposed weighted stacking algorithm and the conventional stacking algorithm is conducted through testing on synthetics and a real data set from New Mexico, USA. This weighted stacking algorithm achieves the primary goal of signal-to-noise ratio improvement while at the same time providing better resolution, wider bandwidth, and a higher signal-to-noise ratio than the conventional stack. A novel hydrocarbon indicator [the water-filled porosity (S wv)], which is estimated from the ratio of P-velocity to S-velocity (Vp/Vs), is proposed and applied to characterize clastic hydrocarbon reservoirs in the North Sea. The separation between pore fluids and lithologies is enhanced by mapping from V p/Vs to Swv using an empirical crossplot-derived relationship. The Swv-V p/Vs plane still does not produce unique interpretations in many situations. However, the critical distinction, which is between hydrocarbon-bearing sands and all other geologic/reservoir configurations, is defined. Porosity is the dominant factor controlling reservoir signature for carbonate rocks. Acoustic impedance and seismic amplitudes are porosity and lithology indicators. Angle-dependent reflectivity effects are introduced for determination of fluid charactersitics by simultaneous elastic impedance inversion of three non-overlapping migrated common-angle stacked sections for P- and S-impedance (Ip and Is). Deviations of points from a water-filled baseline in the Ip-I s plane define a gas potential section that is used for direct identification of gas zones in the dolomitized limestone reservoirs of the Turner Valley Formation in southern Alberta, Canada. There is consistency with the known gas production at a well and agreement with gas index sections obtained through the use of Lame parameter

  15. Differential seed handling by two African primates affects seed fate and establishment of large-seeded trees

    NASA Astrophysics Data System (ADS)

    Gross-Camp, Nicole D.; Kaplin, Beth A.

    2011-11-01

    We examined the influence of seed handling by two semi-terrestrial African forest primates, chimpanzees ( Pan troglodytes) and l'Hoest's monkeys ( Cercopithecus lhoesti), on the fate of large-seeded tree species in an afromontane forest. Chimpanzees and l'Hoest's monkeys dispersed eleven seed species over one year, with quantity and quality of dispersal varying through time. Primates differed in their seed handling behaviors with chimpanzees defecating large seeds (>0.5 cm) significantly more than l'Hoest's. Furthermore, they exhibited different oral-processing techniques with chimpanzees discarding wadges containing many seeds and l'Hoest's monkeys spitting single seeds. A PCA examined the relationship between microhabitat characteristics and the site where primates deposited seeds. The first two components explained almost half of the observed variation. Microhabitat characteristics associated with sites where seeds were defecated had little overlap with those characteristics describing where spit seeds arrived, suggesting that seed handling in part determines the location where seeds are deposited. We monitored a total of 552 seed depositions through time, recording seed persistence, germination, and establishment. Defecations were deposited significantly farther from an adult conspecific than orally-discarded seeds where they experienced the greatest persistence but poorest establishment. In contrast, spit seeds were deposited closest to an adult conspecific but experienced the highest seed establishment rates. We used experimental plots to examine the relationship between seed handling, deposition site, and seed fate. We found a significant difference in seed handling and fate, with undispersed seeds in whole fruits experiencing the lowest establishment rates. Seed germination differed by habitat type with open forest experiencing the highest rates of germination. Our results highlight the relationship between primate seed handling and deposition site and seed

  16. Genome-wide association study in arabidopsis thaliana of natural variation in seed oil melting point, a widespread adaptive trait in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed oil melting point is an adaptive, quantitative trait determined by the relative proportions of the fatty acids that compose the oil. Micro- and macro-evolutionary evidence suggests selection has changed the melting point of seed oils to co-vary with germination temperatures because of a trade-o...

  17. Supplying dextrose before insemination and L-arginine during the last third of pregnancy in sow diets: effects on within-litter variation of piglet birth weight.

    PubMed

    Quesnel, H; Quiniou, N; Roy, H; Lottin, A; Boulot, S; Gondret, F

    2014-04-01

    Preweaning piglet mortality is largely attributed to the incidence of low birth weight and birth weight variation within the litter. Therefore, developing strategies to increase within-litter uniformity of piglet birth weight is important. This study investigated the effects of different feeding strategies based on specific nutrient supplies in sow diet on the within-litter variation of piglet birth weight (BW0). Four batches of highly prolific crossbred Landrace × Large White sows were used. Three dietary treatments were compared: supplies of dextrose during the week before insemination (190 g/d) and of L-arginine (25.5 g/d) from d 77 of pregnancy until term (DEXA, n = 26); a dietary supplementation of L-arginine only (25.5 g/d), from d 77 of pregnancy until term (ARGI, n = 24); and no supplementation to a standard gestation diet (CTL; n = 23). Total born piglets (TB), i.e., piglets born alive (BA) and stillborn piglets, were numbered and weighed at birth and at weaning. Data were analyzed by ANOVA using the MIXED procedure in a model that included dietary treatment (ARGI, DEXA, and CTL), initial parity (1, 2 and 3, 4, and more), and backfat thickness (below or above the average value at the onset of the experiment: 15.7 mm) as the main effects and batch as random effect. The treatment did not influence (P > 0.10) the number of piglets at birth (on average 15.6 ± 3.8 and 14.2 ± 3.6 for TB and BA, respectively) or piglet BW0 (on average 1.48 ± 0.26 and 1.50 ± 0.26 kg for TB and BA, respectively). The coefficient of variation of piglet BW0 (CV(BW0)) was less in litters from ARGI sows than in litters from CTL sows and intermediate in litters from DEXA sows (for TB: 21.4, 23.4, and 25.7%, P = 0.08; for BA: 20.6, 22.5, and 25.4%, P = 0.03, in the ARGI, DEXA, and CTL groups, respectively). Irrespective of diet, CV(BW0) was less (P < 0.01) in litters with 16 TB piglets or less than in the largest litters (20.9 vs. 26.5%). Litter growth rate during lactation and

  18. Phytochemical Evaluation of Moth Bean (Vigna aconitifolia L.) Seeds and Their Divergence

    PubMed Central

    Gupta, Neha; Shrivastava, Nidhi; Singh, Pramod Kumar; Bhagyawant, Sameer S.

    2016-01-01

    In the present study, phytochemical contents of 25 moth bean (Vigna aconitifolia) seed accessions were evaluated. This includes protease inhibitors, phytic acid, radical scavenging activity, and tannins. The studies revealed significant variation in the contents of theses phytochemicals. Presence of photochemical composition was correlated with seed storage proteins like albumin and globulin. Qualitative identification of total seed storage protein abundance across two related moth bean accessions using two-dimensional gel electrophoresis (2D-GE) was performed. Over 20 individual protein fractions were distributed over the gel as a series of spots in two moth bean accessions. Seed proteome accumulated spots of high intensity over a broad range of pI values of 3–10 in a molecular weight range of 11–170 kDa. In both seed accessions maximum protein spots are seen in the pI range of 6–8. PMID:27239343

  19. High-Molecular-Weight Paired Helical Filaments from Alzheimer Brain Induces Seeding of Wild-Type Mouse Tau into an Argyrophilic 4R Tau Pathology in Vivo.

    PubMed

    Audouard, Emilie; Houben, Sarah; Masaracchia, Caterina; Yilmaz, Zehra; Suain, Valérie; Authelet, Michèle; De Decker, Robert; Buée, Luc; Boom, Alain; Leroy, Karelle; Ando, Kunie; Brion, Jean-Pierre

    2016-10-01

    In Alzheimer disease, the development of tau pathology follows neuroanatomically connected pathways, suggesting that abnormal tau species might recruit normal tau by passage from cell to cell. Herein, we analyzed the effect of stereotaxic brain injection of human Alzheimer high-molecular-weight paired helical filaments (PHFs) in the dentate gyrus of wild-type and mutant tau THY-Tau22 mice. After 3 months of incubation, wild-type and THY-Tau22 mice developed an atrophy of the dentate gyrus and a tau pathology characterized by Gallyas and tau-positive grain-like inclusions into granule cells that extended in the hippocampal hilus and eventually away into the alveus, and the fimbria. Gallyas-positive neuropil threads and oligodendroglial coiled bodies were also observed. These tau inclusions were composed only of mouse tau, and were immunoreactive with antibodies to 4R tau, phosphotau, misfolded tau, ubiquitin, and p62. Although local hyperphosphorylation of tau was increased in the dentate gyrus in THY-Tau22 mice, the development of neurofibrillary tangles made of mutant human tau was not accelerated in the hippocampus, indicating that wild-type human PHFs were inefficient in seeding tau aggregates made of G272V/P301S mutant human tau. Our results indicate thus that injection of human wild-type Alzheimer PHF seeded aggregation of wild-type murine tau into an argyrophilic 4R tau pathology, and constitutes an interesting model independent of expression of a mutant tau protein.

  20. High-Molecular-Weight Paired Helical Filaments from Alzheimer Brain Induces Seeding of Wild-Type Mouse Tau into an Argyrophilic 4R Tau Pathology in Vivo.

    PubMed

    Audouard, Emilie; Houben, Sarah; Masaracchia, Caterina; Yilmaz, Zehra; Suain, Valérie; Authelet, Michèle; De Decker, Robert; Buée, Luc; Boom, Alain; Leroy, Karelle; Ando, Kunie; Brion, Jean-Pierre

    2016-10-01

    In Alzheimer disease, the development of tau pathology follows neuroanatomically connected pathways, suggesting that abnormal tau species might recruit normal tau by passage from cell to cell. Herein, we analyzed the effect of stereotaxic brain injection of human Alzheimer high-molecular-weight paired helical filaments (PHFs) in the dentate gyrus of wild-type and mutant tau THY-Tau22 mice. After 3 months of incubation, wild-type and THY-Tau22 mice developed an atrophy of the dentate gyrus and a tau pathology characterized by Gallyas and tau-positive grain-like inclusions into granule cells that extended in the hippocampal hilus and eventually away into the alveus, and the fimbria. Gallyas-positive neuropil threads and oligodendroglial coiled bodies were also observed. These tau inclusions were composed only of mouse tau, and were immunoreactive with antibodies to 4R tau, phosphotau, misfolded tau, ubiquitin, and p62. Although local hyperphosphorylation of tau was increased in the dentate gyrus in THY-Tau22 mice, the development of neurofibrillary tangles made of mutant human tau was not accelerated in the hippocampus, indicating that wild-type human PHFs were inefficient in seeding tau aggregates made of G272V/P301S mutant human tau. Our results indicate thus that injection of human wild-type Alzheimer PHF seeded aggregation of wild-type murine tau into an argyrophilic 4R tau pathology, and constitutes an interesting model independent of expression of a mutant tau protein. PMID:27497324

  1. Geographic Variation in the Association between Ambient Fine Particulate Matter (PM2.5) and Term Low Birth Weight in the United States

    PubMed Central

    Hao, Yongping; Strosnider, Heather; Balluz, Lina; Qualters, Judith R.

    2015-01-01

    Background Studies on the association between prenatal exposure to fine particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) and term low birth weight (LBW) have resulted in inconsistent findings. Most studies were conducted in snapshots of small geographic areas and no national study exists. Objectives We investigated geographic variation in the associations between ambient PM2.5 during pregnancy and term LBW in the contiguous United States. Methods A total of 3,389,450 term singleton births in 2002 (37–44 weeks gestational age and birth weight of 1,000–5,500 g) were linked to daily PM2.5 via imputed birth days. We generated average daily PM2.5 during the entire pregnancy and each trimester. Multi-level logistic regression models with county-level random effects were used to evaluate the associations between term LBW and PM2.5 during pregnancy. Results Without adjusting for covariates, the odds of term LBW increased 2% [odds ratio (OR) = 1.02; 95% CI: 1.00, 1.03] for every 5-μg/m3 increase in PM2.5 exposure during the second trimester only, which remained unchanged after adjusting for county-level poverty (OR = 1.02; 95% CI: 1.01, 1.04). The odds did change to null after adjusting for individual-level predictors (OR = 1.00; 95% CI: 0.99, 1.02). Multi-level analyses, stratified by census division, revealed significant positive associations of term LBW and PM2.5 exposure (during the entire pregnancy or a specific trimester) in three census divisions of the United States: Middle Atlantic, East North Central, and West North Central, and significant negative association in the Mountain division. Conclusions Our study provided additional evidence on the associations between PM2.5 exposure during pregnancy and term LBW from a national perspective. The magnitude and direction of the estimated associations between PM2.5 exposure and term LBW varied by geographic locations in the United States. Citation Hao Y, Strosnider H, Balluz L, Qualters JR. 2016

  2. Transcriptome Analysis of a New Peanut Seed Coat Mutant for the Physiological Regulatory Mechanism Involved in Seed Coat Cracking and Pigmentation

    PubMed Central

    Wan, Liyun; Li, Bei; Pandey, Manish K.; Wu, Yanshan; Lei, Yong; Yan, Liying; Dai, Xiaofeng; Jiang, Huifang; Zhang, Juncheng; Wei, Guo; Varshney, Rajeev K.; Liao, Boshou

    2016-01-01

    Seed-coat cracking and undesirable color of seed coat highly affects external appearance and commercial value of peanuts (Arachis hypogaea L.). With an objective to find genetic solution to the above problems, a peanut mutant with cracking and brown colored seed coat (testa) was identified from an EMS treated mutant population and designated as “peanut seed coat crack and brown color mutant line (pscb).” The seed coat weight of the mutant was almost twice of the wild type, and the germination time was significantly shorter than wild type. Further, the mutant had lower level of lignin, anthocyanin, proanthocyanidin content, and highly increased level of melanin content as compared to wild type. Using RNA-Seq, we examined the seed coat transcriptome in three stages of seed development in the wild type and the pscb mutant. The RNA-Seq analysis revealed presence of highly differentially expressed phenylpropanoid and flavonoid pathway genes in all the three seed development stages, especially at 40 days after flowering (DAF40). Also, the expression of polyphenol oxidases and peroxidase were found to be activated significantly especially in the late seed developmental stage. The genome-wide comparative study of the expression profiles revealed 62 differentially expressed genes common across all the three stages. By analyzing the expression patterns and the sequences of the common differentially expressed genes of the three stages, three candidate genes namely c36498_g1 (CCoAOMT1), c40902_g2 (kinesin), and c33560_g1 (MYB3) were identified responsible for seed-coat cracking and brown color phenotype. Therefore, this study not only provided candidate genes but also provided greater insights and molecular genetic control of peanut seed-coat cracking and color variation. The information generated in this study will facilitate further identification of causal gene and diagnostic markers for breeding improved peanut varieties with smooth and desirable seed coat color. PMID

  3. Genetic diversity, population structure and marker trait associations for seed quality traits in cotton (Gossypium hirsutum).

    PubMed

    Badigannavar, Ashok; Myers, Gerald O

    2015-03-01

    Cottonseed contains 16% seed oil and 23% seed protein by weight. High levels of palmitic acid provides a degree of stability to the oil, while the presence of bound gossypol in proteins considerably changes their properties, including their biological value. This study uses genetic principles to identify genomic regions associated with seed oil, protein and fibre content in upland cotton cultivars. Cotton association mapping panel representing the US germplasm were genotyped using amplified fragment length polymorphism markers, yielding 234 polymorphic DNA fragments. Phenotypic analysis showed high genetic variability for the seed traits, seed oil range from 6.47-25.16%, protein from 1.85-28.45% and fibre content from 15.88-37.12%. There were negative correlations between seed oil and protein content.With reference to genetic diversity, the average estimate of FST was 8.852 indicating a low level of genetic differentiation among subpopulations. The AMOVA test revealed that variation was 94% within and 6% among subpopulations. Bayesian population structure identified five subpopulations and was in agreement with their geographical distribution. Among the mixed models analysed, mixed linear model (MLM) identified 21 quantitative trait loci for lint percentage and seed quality traits, such as seed protein and oil. Establishing genetic diversity, population structure and marker trait associations for the seed quality traits could be valuable in understanding the genetic relationships and their utilization in breeding programmes.

  4. Relationships between root characteristics and seed size in two contrasting floras

    NASA Astrophysics Data System (ADS)

    Guerrero-Campo, Joaquín; Fitter, Alastair H.

    2001-04-01

    Plants vary greatly in root system characteristics, but the causes of this variation are poorly understood. We hypothesised that root system size is closely linked to the plant's ecological strategy, and that seed size is correlated with root diameter, as a result of anatomical constraints. We analysed the relationships between root characteristics - root depth, basal root diameter and root type - and other plant attributes in more than 300 plant species from two ecologically and geographically contrasted areas: Britain and NE Spain. We used statistical tests that took into account phylogenetic patterns in the data. Apart from plant life span, only plant height and seed size were related to root size in the adult plants. Plant species with shallow or thin main roots had smaller seeds than species with deep or thick main roots, and species with taproots had bigger seeds than plants with fibrous or especially with adventitious roots. These relationships were consistent in the two floras. Seed size was related to plant height, but this association was weaker than that between seed size and root depth. Root depth explained a significant proportion of the variation in seed weight, independently from life form or dispersal mode and, in some cases, more than either of them. These results suggest that traditional ecological explanations do not adequately explain the relationship between seed and plant adult size, and that there will be other, complementary explanations. In particular, we propose that the relationship between seed size and plant height is secondary. The putative causal sequence is that deep-rooted plants (which are generally taller) have large seeds because of allometric and developmental constraints that mean that only large seeds can produce the thick roots that can grow rapidly to depth.

  5. Optimum harvest maturity for Leymus chinensis seed.

    PubMed

    Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui; Mu, Chunsheng

    2016-01-01

    Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

  6. Optimum harvest maturity for Leymus chinensis seed

    PubMed Central

    Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui

    2016-01-01

    ABSTRACT Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

  7. Pre-dispersal predation effect on seed packaging strategies and seed viability.

    PubMed

    DeSoto, Lucía; Tutor, David; Torices, Rubén; Rodríguez-Echeverría, Susana; Nabais, Cristina

    2016-01-01

    An increased understanding of intraspecific seed packaging (i.e. seed size/number strategy) variation across different environments may improve current knowledge of the ecological forces that drive seed evolution in plants. In particular, pre-dispersal seed predation may influence seed packaging strategies, triggering a reduction of the resources allocated to undamaged seeds within the preyed fruits. Assessing plant reactions to pre-dispersal seed predation is crucial to a better understanding of predation effects, but the response of plants to arthropod attacks remains unexplored. We have assessed the effect of cone predation on the size and viability of undamaged seeds in populations of Juniperus thurifera with contrasting seed packaging strategies, namely, North African populations with single-large-seeded cones and South European populations with multi-small-seeded cones. Our results show that the incidence of predation was lower on the single-large-seeded African cones than on the multi-small-seeded European ones. Seeds from non-preyed cones were also larger and had a higher germination success than uneaten seeds from preyed cones, but only in populations with multi-seeded cones and in cones attacked by Trisetacus sp., suggesting a differential plastic response to predation. It is possible that pre-dispersal seed predation has been a strong selective pressure in European populations with high cone predation rates, being a process which maintains multi-small-seeded cones and empty seeds as a strategy to save some seeds from predation. Conversely, pre-dispersal predation might not have a strong effect in the African populations with single-large-seeded cones characterized by seed germination and filling rates higher than those in the European populations. Our results indicate that differences in pre-dispersal seed predators and predation levels may affect both selection on and intraspecific variation in seed packaging.

  8. Pre-dispersal predation effect on seed packaging strategies and seed viability.

    PubMed

    DeSoto, Lucía; Tutor, David; Torices, Rubén; Rodríguez-Echeverría, Susana; Nabais, Cristina

    2016-01-01

    An increased understanding of intraspecific seed packaging (i.e. seed size/number strategy) variation across different environments may improve current knowledge of the ecological forces that drive seed evolution in plants. In particular, pre-dispersal seed predation may influence seed packaging strategies, triggering a reduction of the resources allocated to undamaged seeds within the preyed fruits. Assessing plant reactions to pre-dispersal seed predation is crucial to a better understanding of predation effects, but the response of plants to arthropod attacks remains unexplored. We have assessed the effect of cone predation on the size and viability of undamaged seeds in populations of Juniperus thurifera with contrasting seed packaging strategies, namely, North African populations with single-large-seeded cones and South European populations with multi-small-seeded cones. Our results show that the incidence of predation was lower on the single-large-seeded African cones than on the multi-small-seeded European ones. Seeds from non-preyed cones were also larger and had a higher germination success than uneaten seeds from preyed cones, but only in populations with multi-seeded cones and in cones attacked by Trisetacus sp., suggesting a differential plastic response to predation. It is possible that pre-dispersal seed predation has been a strong selective pressure in European populations with high cone predation rates, being a process which maintains multi-small-seeded cones and empty seeds as a strategy to save some seeds from predation. Conversely, pre-dispersal predation might not have a strong effect in the African populations with single-large-seeded cones characterized by seed germination and filling rates higher than those in the European populations. Our results indicate that differences in pre-dispersal seed predators and predation levels may affect both selection on and intraspecific variation in seed packaging. PMID:26400794

  9. Surface and Column Variations of CO2 using Weighting Functions for Future Active Remote CO2 sensors and Data from DISCOVER-AQ Field Campaign

    NASA Astrophysics Data System (ADS)

    Yang, M. M.; Choi, Y.; Kooi, S. A.; Browell, E. V.

    2014-12-01

    Fast response (1 Hz) and high precision (< 0.1 ppmv) in situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaign, to investigate the ability of space-based observations to accurately assess near surface conditions related to air quality. The campaign spanned 4 years and took place over four geographically different locations. These included, Washington DC/Baltimore, MD (July 2011), San Joaquin Valley, CA (January - February 2013), Houston, TX (September 2013), and Denver, CO (July-August 2014). With the objective of obtaining better CO2 column calculations, each of these campaigns consisted of missed approaches and approximately two hundred vertical soundings of CO2 (from the surface to about 5 km). In this study, surface and column-averaged CO2 mixing ratio values from the vertical soundings in the four different urban areas are used to examine the temporal and spatial variability of CO2 within the lower troposphere. Tracers such as CO, CH2O, NOx, and NMHCs will be used to identify the source of variations observed in these urban sites. Additionally, we apply nominal CO2 column weighting functions for potential future active remote CO2 sensors operating in the 1.57-mm and 2.05-mm measurement regions to convert the in situ CO2 vertical mixing ratio profiles to variations in CO2 column optical depths, which is what the active remote sensors actually measure. Using statistics calculated from the optical depths at each urban site measured during the DISCOVER-AQ field campaign and for each nominal weighting function, we compare the natural variability of CO2 columns in the lower troposphere; relate the CO2 column variability to surface emissions; and show the measurement requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) in the continental U.S. urban areas.

  10. Comprehensive speciation of low-molecular weight selenium metabolites in mustard seeds using HPLC-electrospray linear trap/Orbitrap tandem mass spectrometry.

    PubMed

    Ouerdane, Laurent; Aureli, Federica; Flis, Paulina; Bierla, Katarzyna; Preud'homme, Hugues; Cubadda, Francesco; Szpunar, Joanna

    2013-09-01

    An analytical methodology based on high-resolution high mass accuracy electrospray ionization (ESI) tandem MS assisted by Se-specific detection using inductively coupled plasma mass spectrometry (ICP MS) was developed for speciation of selenium (Se) in seeds of black mustard (Brassica nigra) grown on Se-rich soil. Size-exclusion LC-ICP MS allowed the determination of the Se distribution according to the molecular mass and the control of the species stability during extraction. The optimization of hydrophilic interaction of LC and cation-exchange HPLC resulted in analytical conditions making it possible to detect and characterize over 30 Se species using ESI MS, including a number of minor (<0.5%) metabolites. Selenoglucosinolates were found to be the most important class of species accounting for at least 15% of the total Se present and over 50% of all the metabolites. They were found particularly unstable during aqueous extraction leading to the loss of Se by volatilization as methylselenonitriles and methylselenoisothiocyanates identified using gas chromatography (GC) with the parallel ICP MS and atmospheric pressure chemical ionization (APCI) MS/MS detection. However, selenoglucosinolates could be efficiently recovered by extraction with 70% methanol. Other classes of identified species included selenoamino acids, selenosugars, selenosinapine and selenourea derivatives. The three types of reactions leading to the formation of selenometabolites were: the Se-S substitution in the metabolic pathway, oxidative reactions of -SeH groups with endogenous biomolecules, and chemical reactions, e.g., esterification, of Se-containing molecules and other biomolecules through functional groups not involving Se. PMID:23925428

  11. Factors associated with inter-institutional variations in sepsis rates of very-low-birth-weight infants in 34 Malaysian neonatal intensive care units

    PubMed Central

    Boo, Nem-Yun; Cheah, Irene Guat-Sim

    2016-01-01

    INTRODUCTION This study aimed to determine whether patient loads, infant status on admission and treatment interventions were significantly associated with inter-institutional variations in sepsis rates in very-low-birth-weight (VLBW) infants in the Malaysian National Neonatal Registry (MNNR). METHODS This was a retrospective study of 3,880 VLBW (≤ 1,500 g) infants admitted to 34 neonatal intensive care units (NICUs) in the MNNR. Sepsis was diagnosed in symptomatic infants with positive blood culture. RESULTS Sepsis developed in 623 (16.1%) infants; 61 (9.8%) had early-onset sepsis (EOS) and 562 (90.2%) had late-onset sepsis (LOS). The median EOS rate of all NICUs was 1.0% (interquartile range [IQR] 0%, 2.0%). Compared with NICUs reporting no EOS (n = 14), NICUs reporting EOS (n = 20) had significantly higher patient loads (total live births, admissions, VLBW infants, outborns); more mothers with a history of abortions, and antenatal steroids and intrapartum antibiotic use; more infants requiring resuscitation procedures at birth; higher rates of surfactant therapy, pneumonia and insertion of central venous catheters. The median LOS rate of all NICUs was 14.5% (IQR 7.8%, 19.2%). Compared with NICUs with LOS rates below the first quartile (n = 8), those above the third quartile (n = 8) used less intrapartum antibiotics, and had significantly bigger and more mature infants, more outborns, as well as a higher number of sick infants requiring ventilator support and total parenteral nutrition. CONCLUSION Patient loads, resuscitation at birth, status of infants on admission and treatment interventions were significantly associated with inter-institutional variations in sepsis. PMID:26996633

  12. Phase variation and host immunity against high molecular weight (HMW) adhesins shape population dynamics of nontypeable Haemophilus influenzae within human hosts.

    PubMed

    Davis, Gregg S; Marino, Simeone; Marrs, Carl F; Gilsdorf, Janet R; Dawid, Suzanne; Kirschner, Denise E

    2014-08-21

    Nontypeable Haemophilus influenzae (NTHi) is a bacterium that resides within the human pharynx. Because NTHi is human-restricted, its long-term survival is dependent upon its ability to successfully colonize new hosts. Adherence to host epithelium, mediated by bacterial adhesins, is one of the first steps in NTHi colonization. NTHi express several adhesins, including the high molecular weight (HMW) adhesins that mediate attachment to the respiratory epithelium where they interact with the host immune system to elicit a strong humoral response. hmwA, which encodes the HMW adhesin, undergoes phase variation mediated by 7-base pair tandem repeats located within its promoter region. Repeat number affects both hmwA transcription and HMW-adhesin production such that as the number of repeats increases, adhesin production decreases. Cells expressing large amounts of HMW adhesins may be critical for the establishment and maintenance of NTHi colonization, but they might also incur greater fitness costs when faced with an adhesin-specific antibody-mediated immune response. We hypothesized that the occurrence of large deletion events within the hmwA repeat region allows NTHi cells to maintain adherence in the presence of antibody-mediated immunity. To study this, we developed a mathematical model, incorporating hmwA phase variation and antibody-mediated immunity, to explore the trade-off between bacterial adherence and immune evasion. The model predicts that antibody levels and avidity, catastrophic loss rates, and population carrying capacity all significantly affected numbers of adherent NTHi cells within a host. These results suggest that the occurrence of large, yet rare, deletion events allows for stable maintenance of a small population of adherent cells in spite of HMW adhesin specific antibody-mediated immunity. These adherent subpopulations may be important for sustaining colonization and/or maintaining transmission. PMID:24747580

  13. Genetic variation for lettuce seed thermoinhibition is associated with temperature-sensitive expression of abscisic Acid, gibberellin, and ethylene biosynthesis, metabolism, and response genes.

    PubMed

    Argyris, Jason; Dahal, Peetambar; Hayashi, Eiji; Still, David W; Bradford, Kent J

    2008-10-01

    Lettuce (Lactuca sativa 'Salinas') seeds fail to germinate when imbibed at temperatures above 25 degrees C to 30 degrees C (termed thermoinhibition). However, seeds of an accession of Lactuca serriola (UC96US23) do not exhibit thermoinhibition up to 37 degrees C in the light. Comparative genetics, physiology, and gene expression were analyzed in these genotypes to determine the mechanisms governing the regulation of seed germination by temperature. Germination of the two genotypes was differentially sensitive to abscisic acid (ABA) and gibberellin (GA) at elevated temperatures. Quantitative trait loci associated with these phenotypes colocated with a major quantitative trait locus (Htg6.1) from UC96US23 conferring germination thermotolerance. ABA contents were elevated in Salinas seeds that exhibited thermoinhibition, consistent with the ability of fluridone (an ABA biosynthesis inhibitor) to improve germination at high temperatures. Expression of many genes involved in ABA, GA, and ethylene biosynthesis, metabolism, and response was differentially affected by high temperature and light in the two genotypes. In general, ABA-related genes were more highly expressed when germination was inhibited, and GA- and ethylene-related genes were more highly expressed when germination was permitted. In particular, LsNCED4, a gene encoding an enzyme in the ABA biosynthetic pathway, was up-regulated by high temperature only in Salinas seeds and also colocated with Htg6.1. The temperature sensitivity of expression of LsNCED4 may determine the upper temperature limit for lettuce seed germination and may indirectly influence other regulatory pathways via interconnected effects of increased ABA biosynthesis.

  14. Seed coat darkening in Cowpea bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed coat of cowpea bean (Vigna unguiculata L. Walp) slowly browns to a darker color during storage. High temperature and humidity during storage might contribute to this color change. Variation in browning rate among seeds in a lot leads to a mixture of seed colors creating an unacceptable product...

  15. Variations and Determinants of Mortality and Length of Stay of Very Low Birth Weight and Very Low for Gestational Age Infants in Seven European Countries.

    PubMed

    Fatttore, Giovanni; Numerato, Dino; Peltola, Mikko; Banks, Helen; Graziani, Rebecca; Heijink, Richard; Over, Eelco; Klitkou, Søren Toksvig; Fletcher, Eilidh; Mihalicza, Péter; Sveréus, Sofia

    2015-12-01

    The EuroHOPE very low birth weight and very low for gestational age infants study aimed to measure and explain variation in mortality and length of stay (LoS) in the populations of seven European nations (Finland, Hungary, Italy (only the province of Rome), the Netherlands, Norway, Scotland and Sweden). Data were linked from birth, hospital discharge and mortality registries. For each infant basic clinical and demographic information, infant mortality and LoS at 1 year were retrieved. In addition, socio-economic variables at the regional level were used. Results based on 16,087 infants confirm that gestational age and Apgar score at 5 min are important determinants of both mortality and LoS. In most countries, infants admitted or transferred to third-level hospitals showed lower probability of death and longer LoS. In the meta-analyses, the combined estimates show that being male, multiple births, presence of malformations, per capita income and low population density are significant risk factors for death. It is essential that national policies improve the quality of administrative datasets and address systemic problems in assigning identification numbers at birth. European policy should aim at improving the comparability of data across jurisdictions. PMID:26633869

  16. Genetic variation in salt tolerance during seed germination in a backcross inbred line population and advanced breeding lines derived from upland cotton x pima cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed germination is a crucial phase of the plant life cycle that affects its establishment and productivity. However, information on salt tolerance at this phase is limited. Pima cotton (Gossypium barbadense L.) may be more salt tolerant during germination than Upland cotton (G. hirsutum L.) based o...

  17. Updated Methods for Seed Shape Analysis

    PubMed Central

    Cervantes, Emilio; Martín, José Javier; Saadaoui, Ezzeddine

    2016-01-01

    Morphological variation in seed characters includes differences in seed size and shape. Seed shape is an important trait in plant identification and classification. In addition it has agronomic importance because it reflects genetic, physiological, and ecological components and affects yield, quality, and market price. The use of digital technologies, together with development of quantification and modeling methods, allows a better description of seed shape. Image processing systems are used in the automatic determination of seed size and shape, becoming a basic tool in the study of diversity. Seed shape is determined by a variety of indexes (circularity, roundness, and J index). The comparison of the seed images to a geometrical figure (circle, cardioid, ellipse, ellipsoid, etc.) provides a precise quantification of shape. The methods of shape quantification based on these models are useful for an accurate description allowing to compare between genotypes or along developmental phases as well as to establish the level of variation in different sets of seeds. PMID:27190684

  18. [Seed geography: its concept and basic scientific issues].

    PubMed

    Yu, Shun-Li; Wang, Zong-Shuai; Zeren, Wangmu

    2010-01-01

    In this paper, a new concept 'seed geography' was provided, and its definition, research contents, and scientific issues were put forward. Seed geography is a newly developed interdisciplinary science from plant geography, seed ecology, and phytosociology, which studies the geographic variation patterns of seed biological traits as well as their relationships with environmental factors from macroscopic to microscopic, and the seed formation, development, and change trends. The main research contents would include geography of seed mass, geography of seed chemical components, geography of seed morphology, geography of seed cell biological characteristics, geography of seed physiological characteristics, geography of seed genetic characteristics, and geography of flower and fruit. To explore the scientific issues in seed geography would help us to better understand the long-term adaptation and evolution of seed characteristics to natural environments.

  19. Seasonal, sex and live weight variations in feed and water consumptions of adult captive African Giant rats (Cricetomys gambianus, Waterhouse-1840) kept individually in cages.

    PubMed

    Dzenda, T; Ayo, J O; Lakpini, C A M; Adelaiye, A B

    2013-06-01

    Adult African Giant rats (Cricetomys gambianus, Waterhouse) (AGRs) (n = 231) of both sexes (117 bucks, 114 does) were live-trapped in the wild in Zaria, Nigeria. Live weight (LW), daily feed consumption (FC) and water consumption (WC) of the AGRs were measured during the cold-dry (CDS), hot-dry (HDS) and rainy (RS) seasons for 2 years with the aim of determining seasonal, sex and LW variations. Feed consumption was significantly different (p < 0.001) between all the seasons, with the lowest mean value recorded during the HDS, while the highest was obtained during the RS. Water consumption was also lowest (p < 0.001) during the HDS but did not differ significantly (p > 0.05) between the CDS and RS. Both feed and water consumptions were higher (p < 0.01) in the males (bucks) than the females (does) during the CDS and HDS, but the sex difference was not significant (p > 0.05) during the RS. Feed consumption correlated positively (p < 0.0001) with WC and relative humidity, but negatively (p < 0.0001) with LW, ambient temperature and heat index. In conclusion, both feed and water consumptions in AGRs decrease with increased seasonal heat and adult LW and are lower in does than in bucks during the dry seasons (CDS and HDS). Intervention may be indicated during the HDS to improve feed and water consumptions for optimal performance of the AGRs.

  20. Variation of the phytotoxicity of municipal solid waste incinerator bottom ash on wheat (Triticum aestivum L.) seed germination with leaching conditions.

    PubMed

    Phoungthong, Khamphe; Zhang, Hua; Shao, Li-Ming; He, Pin-Jing

    2016-03-01

    Municipal solid waste incinerator bottom ash (MSWIBA) has long been regarded as an alternative building material in the construction industry. However, the pollutants contained in the bottom ash could potentially leach out and contaminate the local environment, which presents an obstacle to the reuse of the materials. To evaluate the environmental feasibility of using MSWIBA as a recycled material in construction, the leaching derived ecotoxicity was assessed. The leaching behavior of MSWIBA under various conditions, including the extractant type, leaching time, liquid-to-solid (L/S) ratio, and leachate pH were investigated, and the phytotoxicity of these leachates on wheat (Triticum aestivum L.) seed germination was determined. Moreover, the correlation between the germination index and the concentrations of various chemical constituents in the MSWIBA leachates was assessed using multivariate statistics with principal component analysis and Pearson's correlation analysis. It was found that, heavy metal concentrations in the leachate were pH and L/S ratio dependent, but were less affected by leaching time. Heavy metals were the main pollutants present in wheat seeds. Heavy metals (especially Ba, Cr, Cu and Pb) had a substantial inhibitory effect on wheat seed germination and root elongation. To safely use MSWIBA in construction, the potential risk and ecotoxicity of leached materials must be addressed.

  1. Variation of the phytotoxicity of municipal solid waste incinerator bottom ash on wheat (Triticum aestivum L.) seed germination with leaching conditions.

    PubMed

    Phoungthong, Khamphe; Zhang, Hua; Shao, Li-Ming; He, Pin-Jing

    2016-03-01

    Municipal solid waste incinerator bottom ash (MSWIBA) has long been regarded as an alternative building material in the construction industry. However, the pollutants contained in the bottom ash could potentially leach out and contaminate the local environment, which presents an obstacle to the reuse of the materials. To evaluate the environmental feasibility of using MSWIBA as a recycled material in construction, the leaching derived ecotoxicity was assessed. The leaching behavior of MSWIBA under various conditions, including the extractant type, leaching time, liquid-to-solid (L/S) ratio, and leachate pH were investigated, and the phytotoxicity of these leachates on wheat (Triticum aestivum L.) seed germination was determined. Moreover, the correlation between the germination index and the concentrations of various chemical constituents in the MSWIBA leachates was assessed using multivariate statistics with principal component analysis and Pearson's correlation analysis. It was found that, heavy metal concentrations in the leachate were pH and L/S ratio dependent, but were less affected by leaching time. Heavy metals were the main pollutants present in wheat seeds. Heavy metals (especially Ba, Cr, Cu and Pb) had a substantial inhibitory effect on wheat seed germination and root elongation. To safely use MSWIBA in construction, the potential risk and ecotoxicity of leached materials must be addressed. PMID:26745383

  2. Genetic Variation for Thermotolerance in Lettuce Seed Germination Is Associated with Temperature-Sensitive Regulation of ETHYLENE RESPONSE FACTOR1 (ERF1).

    PubMed

    Yoong, Fei-Yian; O'Brien, Laurel K; Truco, Maria Jose; Huo, Heqiang; Sideman, Rebecca; Hayes, Ryan; Michelmore, Richard W; Bradford, Kent J

    2016-01-01

    Seeds of most lettuce (Lactuca sativa) cultivars are susceptible to thermoinhibition, or failure to germinate at temperatures above approximately 28°C, creating problems for crop establishment in the field. Identifying genes controlling thermoinhibition would enable the development of cultivars lacking this trait and, therefore, being less sensitive to high temperatures during planting. Seeds of a primitive accession (PI251246) of lettuce exhibited high-temperature germination capacity up to 33°C. Screening a recombinant inbred line population developed from PI215246 and cv Salinas identified a major quantitative trait locus (Htg9.1) from PI251246 associated with the high-temperature germination phenotype. Further genetic analyses discovered a tight linkage of the Htg9.1 phenotype with a specific DNA marker (NM4182) located on a single genomic sequence scaffold. Expression analyses of the 44 genes encoded in this genomic region revealed that only a homolog of Arabidopsis (Arabidopsis thaliana) ETHYLENE RESPONSE FACTOR1 (termed LsERF1) was differentially expressed between PI251246 and cv Salinas seeds imbibed at high temperature (30°C). LsERF1 belongs to a large family of transcription factors associated with the ethylene-signaling pathway. Physiological assays of ethylene synthesis, response, and action in parental and near-isogenic Htg9.1 genotypes strongly implicate LsERF1 as the gene responsible for the Htg9.1 phenotype, consistent with the established role for ethylene in germination thermotolerance of Compositae seeds. Expression analyses of genes associated with the abscisic acid and gibberellin biosynthetic pathways and results of biosynthetic inhibitor and hormone response experiments also support the hypothesis that differential regulation of LsERF1 expression in PI251246 seeds elevates their upper temperature limit for germination through interactions among pathways regulated by these hormones. Our results support a model in which LsERF1 acts through

  3. Genetic Variation for Thermotolerance in Lettuce Seed Germination Is Associated with Temperature-Sensitive Regulation of ETHYLENE RESPONSE FACTOR1 (ERF1).

    PubMed

    Yoong, Fei-Yian; O'Brien, Laurel K; Truco, Maria Jose; Huo, Heqiang; Sideman, Rebecca; Hayes, Ryan; Michelmore, Richard W; Bradford, Kent J

    2016-01-01

    Seeds of most lettuce (Lactuca sativa) cultivars are susceptible to thermoinhibition, or failure to germinate at temperatures above approximately 28°C, creating problems for crop establishment in the field. Identifying genes controlling thermoinhibition would enable the development of cultivars lacking this trait and, therefore, being less sensitive to high temperatures during planting. Seeds of a primitive accession (PI251246) of lettuce exhibited high-temperature germination capacity up to 33°C. Screening a recombinant inbred line population developed from PI215246 and cv Salinas identified a major quantitative trait locus (Htg9.1) from PI251246 associated with the high-temperature germination phenotype. Further genetic analyses discovered a tight linkage of the Htg9.1 phenotype with a specific DNA marker (NM4182) located on a single genomic sequence scaffold. Expression analyses of the 44 genes encoded in this genomic region revealed that only a homolog of Arabidopsis (Arabidopsis thaliana) ETHYLENE RESPONSE FACTOR1 (termed LsERF1) was differentially expressed between PI251246 and cv Salinas seeds imbibed at high temperature (30°C). LsERF1 belongs to a large family of transcription factors associated with the ethylene-signaling pathway. Physiological assays of ethylene synthesis, response, and action in parental and near-isogenic Htg9.1 genotypes strongly implicate LsERF1 as the gene responsible for the Htg9.1 phenotype, consistent with the established role for ethylene in germination thermotolerance of Compositae seeds. Expression analyses of genes associated with the abscisic acid and gibberellin biosynthetic pathways and results of biosynthetic inhibitor and hormone response experiments also support the hypothesis that differential regulation of LsERF1 expression in PI251246 seeds elevates their upper temperature limit for germination through interactions among pathways regulated by these hormones. Our results support a model in which LsERF1 acts through

  4. Genetic Variation for Thermotolerance in Lettuce Seed Germination Is Associated with Temperature-Sensitive Regulation of ETHYLENE RESPONSE FACTOR1 (ERF1)1[OPEN

    PubMed Central

    O’Brien, Laurel K.; Truco, Maria Jose; Huo, Heqiang; Sideman, Rebecca; Hayes, Ryan; Michelmore, Richard W.

    2016-01-01

    Seeds of most lettuce (Lactuca sativa) cultivars are susceptible to thermoinhibition, or failure to germinate at temperatures above approximately 28°C, creating problems for crop establishment in the field. Identifying genes controlling thermoinhibition would enable the development of cultivars lacking this trait and, therefore, being less sensitive to high temperatures during planting. Seeds of a primitive accession (PI251246) of lettuce exhibited high-temperature germination capacity up to 33°C. Screening a recombinant inbred line population developed from PI215246 and cv Salinas identified a major quantitative trait locus (Htg9.1) from PI251246 associated with the high-temperature germination phenotype. Further genetic analyses discovered a tight linkage of the Htg9.1 phenotype with a specific DNA marker (NM4182) located on a single genomic sequence scaffold. Expression analyses of the 44 genes encoded in this genomic region revealed that only a homolog of Arabidopsis (Arabidopsis thaliana) ETHYLENE RESPONSE FACTOR1 (termed LsERF1) was differentially expressed between PI251246 and cv Salinas seeds imbibed at high temperature (30°C). LsERF1 belongs to a large family of transcription factors associated with the ethylene-signaling pathway. Physiological assays of ethylene synthesis, response, and action in parental and near-isogenic Htg9.1 genotypes strongly implicate LsERF1 as the gene responsible for the Htg9.1 phenotype, consistent with the established role for ethylene in germination thermotolerance of Compositae seeds. Expression analyses of genes associated with the abscisic acid and gibberellin biosynthetic pathways and results of biosynthetic inhibitor and hormone response experiments also support the hypothesis that differential regulation of LsERF1 expression in PI251246 seeds elevates their upper temperature limit for germination through interactions among pathways regulated by these hormones. Our results support a model in which LsERF1 acts through

  5. Identification and mapping of a major gene (Ft1) involved in fructification time in the interspecific cross Coffea pseudozanguebariae x C. liberica var. Dewevrei: impact on caffeine content and seed weight.

    PubMed

    Akaffou, D S; Ky, C L; Barre, P; Hamon, S; Louarn, J; Noirot, M

    2003-05-01

    Fructification time was studied in the interspecific cross Coffea pseudozanguebariae x C. liberica var. Dewevrei (PSE x DEW). Parental species, F(1) hybrids and offspring of the first backcross generation (BC(1)), consisting of F(1) x PSE (BCPSE) and F(1) x DEW (BCDEW) plants, were observed. Fructification time can be split into two independent visual phases: the full-growth period, from blooming up to the end of fruit growth, and the maturation phase, defined by the green to red color change. Fructification time was found to be an additive trait. The full-growth period showed a bimodal distribution in the BCDEW hybrid, suggesting the involvement of Ft1, a major gene that was mapped on linkage group E. The main effects of Ft1 were to lower caffeine content and 100-seed weight, without any impact on chlorogenic acid, trigonelline and sucrose contents. Two molecular markers were identified that bracket Ft1 and which could be used for early marker-assisted selection.

  6. Effect of polyphenols extracted from Tamarind (Tamarindus indica L.) seed coat on physiological changes, heterophil/lymphocyte ratio, oxidative stress and body weight of broilers (Gallus domesticus) under chronic heat stress.

    PubMed

    Aengwanich, Worapol; Suttajit, Maitree

    2010-04-01

    The aim of this experiment was to determine the effect of polyphenols extracted from tamarind (Tamarindus indica L.) seed coat on physiological changes, oxidative stress and production of male broilers maintained at high environmental temperatures. The results found that body temperature and respiratory rate of broilers maintained at 38 +/- 2 degrees C was higher than broilers maintained at 26 +/- 2 degrees C (P < 0.05). On day 1, the heterophil/ lymphocyte ratio of broilers maintained at 38 +/- 2 degrees C and received polyphenols at 300 and 400 mg/kg in diets was lower than broilers that received polyphenols at 0 and 200 mg/kg in diets (P < 0.05). At week 1, the malondialdehyde of the broilers maintained at 38 +/- 2 degrees C who received polyphenols at 400 mg/ kg in their diet was lower than broilers that received polyphenols at 100 and 200 mg/kg in diets (P < 0.05). At week 1, the body weights of broilers that were maintained at 38 +/- 2 degrees C who received polyphenols at 100-500 mg/ kg in diets, and broilers maintained at 26 +/- 2 degrees C were higher than that of the control group which had not been treated with a polyphenol diet (P < 0.05). This study indicated that polyphenols could reduce heat stress, oxidative stress and improve the growth rate of heat-stressed broilers.

  7. Seed germination and seedling fitness in Mesua ferrea L. in relation to fruit size and seed number per fruit

    NASA Astrophysics Data System (ADS)

    Khan, M. Latif; Bhuyan, Putul; Shankar, Uma; Todaria, Nagendra P.

    1999-11-01

    Effect of fruit size and seediness (seed number per fruit) was examined on germination and early growth of seedlings in Mesua ferrea L. Fruiting incidence (number of fruited trees in a population) and fruit loading (number of fruits per tree) vary from one year to the other, and were greater in 1997 than in 1998. Seeds from large fruits (> 40 g) are preferred for forestry plantations and those from small fruits (< 40 g) are discarded, despite a greater proportion of small fruits (63.2 %) than large fruits (36.8 %). A fruit, large or small in size, may contain one, two, three or four seeds. The germination percentage of seeds increased from 1-seeded through 4-seeded fruits both in laboratory and greenhouse conditions, and both in case of large and small fruits. Conversely, the mean seed weight and germination time decreased along this gradient, i.e. seeds from 1-seeded fruits were the heaviest and required maximum time for germination, and the seeds from 4-seeded fruits were the lightest and required minimum time for germination. The seeds from small fruits were lighter in weight, achieved lower germination percentages and required greater germination time than the seeds from large fruits in all four seeded categories. Seedlings from seeds from 1-seeded fruits survived better and with stronger vigour after 1 year of growth than seedlings from 2-, 3- and 4-seeded fruits. Further, seedling survival and vigour were greater for seeds from large rather than small fruits.

  8. Variation in seed fatty acid composition and sequence divergence in the FAD2 gene coding region between wild and cultivated sesame.

    PubMed

    Chen, Zhenbang; Tonnis, Brandon; Morris, Brad; Wang, Richard B; Zhang, Amy L; Pinnow, David; Wang, Ming Li

    2014-12-01

    Sesame germplasm harbors genetic diversity which can be useful for sesame improvement in breeding programs. Seven accessions with different levels of oleic acid were selected from the entire USDA sesame germplasm collection (1232 accessions) and planted for morphological observation and re-examination of fatty acid composition. The coding region of the FAD2 gene for fatty acid desaturase (FAD) in these accessions was also sequenced. Cultivated sesame accessions flowered and matured earlier than the wild species. The cultivated sesame seeds contained a significantly higher percentage of oleic acid (40.4%) than the seeds of the wild species (26.1%). Nucleotide polymorphisms were identified in the FAD2 gene coding region between wild and cultivated species. Some nucleotide polymorphisms led to amino acid changes, one of which was located in the enzyme active site and may contribute to the altered fatty acid composition. Based on the morphology observation, chemical analysis, and sequence analysis, it was determined that two accessions were misnamed and need to be reclassified. The results obtained from this study are useful for sesame improvement in molecular breeding programs.

  9. Effects of maternal diet and host quality on oviposition patterns and offspring performance in a seed beetle (Coleoptera: Bruchidae)

    NASA Astrophysics Data System (ADS)

    González-Teuber, Marcia; Segovia, Ricardo; Gianoli, Ernesto

    2008-07-01

    In seed beetles, oviposition decisions may influence the offspring phenotype because eggs constitute the initial resources available for larval development. We tested the effects of host quality variations (small vs. large seeds of the host plant Calystegia sepium, Convolvulaceae) on oviposition patterns and offspring performance of the seed beetle Megacerus eulophus. We also manipulated the maternal diet: high diet quality vs. low diet quality to evaluate possible interactive effects of the maternal nutritional environment and host quality on oviposition patterns. We further assessed the consequences of egg size variation in offspring size. Female M. eulophus fed with high-quality diet (H-diet) laid more eggs and lived longer than females fed with low-quality diet (P-diet). Fecundity decreased under a low-quality host for both maternal diets. The occurrence of maternal environmental effects on egg size plasticity was detected. Under conditions of low-quality host, mothers fed with the high-quality diet produced bigger eggs in comparison with a high-quality host, whereas females fed with the low-quality diet produced smaller ones. Regardless of these differences observed in egg size depending on the maternal diet, progeny emerging from small seeds (low-quality host) showed a similar performance at emergence. Offspring traits were only significantly affected by host quality. Beetles emerging from large seeds had greater body weight and length than those reared on small seeds. Variations in oviposition patterns in response to host quality are discussed.

  10. Myrmecochory and short-term seed fate in Rhamnus alaternus: Ant species and seed characteristics

    NASA Astrophysics Data System (ADS)

    Bas, J. M.; Oliveras, J.; Gómez, C.

    2009-05-01

    Benefits conferred on plants in ant-mediated seed dispersal mutualisms (myrmecochory) depend on the fate of transported seeds. We studied the effects of elaiosome presence, seed size and seed treatment (with and without passage through a bird's digestive tract) on short-term seed fate in Rhamnus alaternus. In our study, we define short-term seed, or initial, seed fate, as the location where ants release the seeds after ant contact with it. The elaiosomes had the most influence on short-term fate, i.e. whether or not seeds were transported to the nest. The workers usually transported big seeds more often than small ones, but small ants did not transport large seeds. Effect of seed size on transport depended on the ant species and on the treatment of the seed (manual extraction simulating a direct fall from the parent plant vs. bird deposition corresponding to preliminary primary dispersal). Probability of removal of elaiosome-bearing seeds to the nest by Aphaenogaster senilis increased with increasing seed weight.

  11. Effects of elevated CO2 and temperature on seed quality.

    PubMed

    Hampton, J G; Boelt, B; Rolston, M P; Chastain, T G

    2013-04-01

    Successful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO2) and temperature during seed production on three seed quality components: seed mass, germination and seed vigour. In response to elevated CO2, seed mass has been reported to both increase and decrease in C3 plants, but not change in C4 plants. Increases are greater in legumes than non-legumes, and there is considerable variation among species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour. Like seed mass, reported seed germination responses to elevated CO2 have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High-temperature stress before developing seeds reach physiological maturity (PM) can reduce germination by inhibiting the ability of the plant to supply the assimilates necessary to synthesize the storage compounds required for germination. Nothing is known concerning the effects of elevated CO2 on seed vigour. However, seed vigour can be reduced by high-temperature stress both before and after PM. High temperatures induce or increase the physiological deterioration of seeds. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required. The predicted environmental changes will lead to losses of seed quality, particularly for seed vigour and possibly germination. The seed

  12. Effects of elevated CO2 and temperature on seed quality.

    PubMed

    Hampton, J G; Boelt, B; Rolston, M P; Chastain, T G

    2013-04-01

    Successful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO2) and temperature during seed production on three seed quality components: seed mass, germination and seed vigour. In response to elevated CO2, seed mass has been reported to both increase and decrease in C3 plants, but not change in C4 plants. Increases are greater in legumes than non-legumes, and there is considerable variation among species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour. Like seed mass, reported seed germination responses to elevated CO2 have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High-temperature stress before developing seeds reach physiological maturity (PM) can reduce germination by inhibiting the ability of the plant to supply the assimilates necessary to synthesize the storage compounds required for germination. Nothing is known concerning the effects of elevated CO2 on seed vigour. However, seed vigour can be reduced by high-temperature stress both before and after PM. High temperatures induce or increase the physiological deterioration of seeds. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required. The predicted environmental changes will lead to losses of seed quality, particularly for seed vigour and possibly germination. The seed

  13. Variations in fatty acid compositions of the seed oil of Eruca sativa Mill. caused by different sowing periods and nitrogen forms

    PubMed Central

    Uğur, Atnan; Süntar, İpek; Aslan, Sinem; Orhan, İlkay Erdoğan; Kartal, Murat; Şekeroğlu, Nazim; Eşiyok, Dursun; Şener, Bilge

    2010-01-01

    Background: Eruca is a native plant genus of the South Europe and central Asia where it has been cultivated since centuries. As the genus name implies, the oil is high in erucic acid. Materials and Methods: In this study, our aim was to investigate the effect of sowing periods (autumn and spring) and three forms of the nitrogen-containing fertilizers (manure, calcium nitrate [Ca(NO3)2, 15.5% N], and ammonium sulphate [(NH4)2SO4, 21% N]) on fatty acid compositions of the oils obtained from Eruca sativa Mill. seeds cultivated. All oils were obtained by maceration of the seeds with n-hexane at room temperature and converted to their methyl ester derivatives by trans-methylesterification reaction using boron-trifluorur (BF3). The fatty acid methyl esters (FAMEs) in the oils were detected by capillary gas chromatography-mass spectrometry (GC-MS). Results: All the samples analyzed were found to contain quite high amounts of erucic acid ranging between 46.64-54.79%, followed by oleic (17.86-19.95%), palmitic (7.25-10.97%), linoleic (4.23-9.72%), and linolenic (1.98-3.01%) acids. Conclusion: Our data pointed out that there is a statistically important alteration caused by these applications on the contents of only C12:0 and C14:0 found as the minor fatty acids, whereas no other fatty acids in the samples seemed to be affected by those criteria. PMID:21120033

  14. High-throughput phenotyping (HTP) identifies seedling root traits linked to variation in seed yield and nutrient capture in field-grown oilseed rape (Brassica napus L.)

    PubMed Central

    Thomas, C. L.; Graham, N. S.; Hayden, R.; Meacham, M. C.; Neugebauer, K.; Nightingale, M.; Dupuy, L. X.; Hammond, J. P.; White, P. J.; Broadley, M. R.

    2016-01-01

    Background and Aims Root traits can be selected for crop improvement. Techniques such as soil excavations can be used to screen root traits in the field, but are limited to genotypes that are well-adapted to field conditions. The aim of this study was to compare a low-cost, high-throughput root phenotyping (HTP) technique in a controlled environment with field performance, using oilseed rape (OSR; Brassica napus) varieties. Methods Primary root length (PRL), lateral root length and lateral root density (LRD) were measured on 14-d-old seedlings of elite OSR varieties (n = 32) using a ‘pouch and wick’ HTP system (∼40 replicates). Six field experiments were conducted using the same varieties at two UK sites each year for 3 years. Plants were excavated at the 6- to 8-leaf stage for general vigour assessments of roots and shoots in all six experiments, and final seed yield was determined. Leaves were sampled for mineral composition from one of the field experiments. Key Results Seedling PRL in the HTP system correlated with seed yield in four out of six (r = 0·50, 0·50, 0·33, 0·49; P < 0·05) and with emergence in three out of five (r = 0·59, 0·22, 0·49; P < 0·05) field experiments. Seedling LRD correlated positively with leaf concentrations of some minerals, e.g. calcium (r = 0·46; P < 0·01) and zinc (r = 0·58; P < 0·001), but did not correlate with emergence, general early vigour or yield in the field. Conclusions Associations between PRL and field performance are generally related to early vigour. These root traits might therefore be of limited additional selection value, given that vigour can be measured easily on shoots/canopies. In contrast, LRD cannot be assessed easily in the field and, if LRD can improve nutrient uptake, then it may be possible to use HTP systems to screen this trait in both elite and more genetically diverse, non-field-adapted OSR. PMID:27052342

  15. To grow or to seed: ecotypic variation in reproductive allocation and cone production by young female Aleppo pine (Pinus halepensis, Pinaceae).

    PubMed

    Climent, José; Prada, M Aránzazu; Calama, Rafael; Chambel, M Regina; de Ron, David Sánchez; Alía, Ricardo

    2008-07-01

    Age and size at the first reproduction and the reproductive allocation of plants are linked to different life history strategies. Aleppo pine only reproduces through seed, and, as such, early female reproduction confers high fitness in its infertile highly fire-prone habitats along the Mediterranean coast because life expectancy is short. We investigated the extent of ecotypic differentiation in female reproductive allocation and examined the relation between early female reproduction and vegetative growth. In a common-garden experiment, the threshold age and size at first female reproduction and female reproductive allocation at age seven differed significantly among Aleppo pine provenances of ecologically distinct origin. Significant correlations among reproductive features of the provenances and the ecological traits of origin were found using different analytical tools. In nonlinear models of cone counts vs. stem volume, medium-sized trees (not the largest trees) produced the highest cone yield, confirming that, at the individual level, early female reproduction is incompatible with fast vegetative growth. The contribution of founder effects and adaptation to contrasting fire regimes may be confounding factors. But considering all traits analyzed, the geographical patterns of resource allocation by Aleppo pine suggest ecotypic specialization for either resource-poor (favoring early reproduction) or resource-rich (favoring vegetative growth) habitats.

  16. Computation and use of volume-weighted-average concentrations to determine long-term variations of selected water-quality constituents in lakes and reservoirs

    USGS Publications Warehouse

    Wells, Frank C.; Schertz, Terry L.

    1984-01-01

    A computer program using the Statistical Analysis System has been developed to perform the arithmetic calculations and regression analyses to determine volume-weighted-average concentrations of selected water-quality constituents in lakes and reservoirs. The program has been used in Texas to show decreasing trends in dissolved-solids and total-phosphorus concentrations in Lake Arlington after the discharge of sewage effluent into the reservoir was stopped. The program also was used to show that the August 1978 and October 1981 floods on the Brazos River greatly decreased the volume-weighted-average concentrations of selected constituents in Hubbard Creek Reservoir and Possum Kingdom Lake.

  17. Some physical properties of tabletted seed of Garcinia kola (HECKEL).

    PubMed

    Onunkwo, G C; Egeonu, H C; Adikwu, M U; Ojile, J E; Olowosulu, A K

    2004-06-01

    The formulation of Garcinia kola seeds into tablet dosage form and evaluation of some physical properties of the tablets are presented. A chemical assay was conducted on the dry, powdered seeds as well as the crude aqueous extract of the seeds. The dry powdered seeds contain 0.003% of flavonoids while the crude extract contained 0.007% of flavonoids based on rutin used as the standard. The powdered material (50 mg) and crude extract (10 mg) were formulated into tablets using the wet granulation method. Named binders were evaluated in these formulations. The various tablet parameters were evaluated, namely: weight variation, thickness and diameter, hardness, friability, disintegration time, dissolution profile and content uniformity. The results indicated that the tablets had good disintegration time, dissolution and hardness/friability profiles. Tablets formulated with starch had the best disintegration properties but were consequently very friable. Tablets formulated from 10 mg of the crude extract needed a larger proportion of diluents, which affected the tablet properties.

  18. Catalog of microRNA seed polymorphisms in vertebrates.

    PubMed

    Zorc, Minja; Skok, Dasa Jevsinek; Godnic, Irena; Calin, George Adrian; Horvat, Simon; Jiang, Zhihua; Dovc, Peter; Kunej, Tanja

    2012-01-01

    MicroRNAs (miRNAs) are a class of non-coding RNA that plays an important role in posttranscriptional regulation of mRNA. Evidence has shown that miRNA gene variability might interfere with its function resulting in phenotypic variation and disease susceptibility. A major role in miRNA target recognition is ascribed to complementarity with the miRNA seed region that can be affected by polymorphisms. In the present study, we developed an online tool for the detection of miRNA polymorphisms (miRNA SNiPer) in vertebrates (http://www.integratomics-time.com/miRNA-SNiPer) and generated a catalog of miRNA seed region polymorphisms (miR-seed-SNPs) consisting of 149 SNPs in six species. Although a majority of detected polymorphisms were due to point mutations, two consecutive nucleotide substitutions (double nucleotide polymorphisms, DNPs) were also identified in nine miRNAs. We determined that miR-SNPs are frequently located within the quantitative trait loci (QTL), chromosome fragile sites, and cancer susceptibility loci, indicating their potential role in the genetic control of various complex traits. To test this further, we performed an association analysis between the mmu-miR-717 seed SNP rs30372501, which is polymorphic in a large number of standard inbred strains, and all phenotypic traits in these strains deposited in the Mouse Phenome Database. Analysis showed a significant association between the mmu-miR-717 seed SNP and a diverse array of traits including behavior, blood-clinical chemistry, body weight size and growth, and immune system suggesting that seed SNPs can indeed have major pleiotropic effects. The bioinformatics analyses, data and tools developed in the present study can serve researchers as a starting point in testing more targeted hypotheses and designing experiments using optimal species or strains for further mechanistic studies.

  19. Genotypic Variation in the Concentration of β-N-Oxalyl-L-α,β-diaminopropionic Acid (β-ODAP) in Grass Pea (Lathyrus sativus L.) Seeds Is Associated with an Accumulation of Leaf and Pod β-ODAP during Vegetative and Reproductive Stages at Three Levels of Water Stress.

    PubMed

    Xiong, Jun-Lan; Xiong, You-Cai; Bai, Xue; Kong, Hai-Yan; Tan, Rui-Yue; Zhu, Hao; Siddique, Kadambot H M; Wang, Jian-Yong; Turner, Neil C

    2015-07-15

    Grass pea (Lathyrus sativus L.) cultivation is limited because of the presence in seeds and tissues of the nonprotein amino acid β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), a neurotoxin that can cause lathyrism in humans. Seven grass pea genotypes differing in seed β-ODAP concentration were grown in pots at three levels of water availability to follow changes in the concentration and amount of β-ODAP in leaves and pods and seeds. The concentration and amount of β-ODAP decreased in leaves in early reproductive development and in pods as they matured, while water stress increased β-ODAP concentration in leaves and pods at these stages. The net amount of β-ODAP in leaves and pods at early podding was positively associated with seed β-ODAP concentration at maturity. We conclude that variation among genotypes in seed β-ODAP concentration results from variation in net accumulation of β-ODAP in leaves and pods during vegetative and early reproductive development.

  20. Relating pore size variation of poly (ɛ-caprolactone) scaffolds to molecular weight of porogen and evaluation of scaffold properties after degradation.

    PubMed

    Columbus, Soumya; Krishnan, Lissy K; Kalliyana Krishnan, V

    2014-05-01

    The major challenge in designing a scaffold for fabricating tissue engineered blood vessels is optimization of its microstructure for supporting uniform cellular in-growth with good mechanical integrity and degradation kinetics suitable for long-term implantation. In this study, we have investigated the feasibility of varying the pore size of poly(ɛ-caprolactone) (PCL) scaffold by altering the molecular weight of porogen and studied the effect of degradation on morphological characteristics and mechanical properties of scaffolds by correlating to the extent of degradation. Scaffolds with two different pore sizes were prepared by solvent casting and particulate leaching where poly(ethylene glycol) (PEG) porogens having two molecular weights (3400 and 8000) were used and subjected to in vitro degradation in phosphate buffered saline (PBS) upto six months. Microcomputed tomography studies of scaffolds revealed narrower pore size distribution when PEG-3400 was used as porogen and had 78% pores in the 12-24 µ range, whereas incorporation of PEG-8000 resulted in broader distribution with only 65% pores in the same range. Degradation resulted in scaffolds with narrower pore size distribution to have better retention of morphological and mechanical characteristics compared to scaffolds with broader distribution. Gravimetric and molecular weight studies also showed that scaffold degradation in both cases was only in initial stages after 6 months and PCL scaffolds had potential to be recommended for vascular tissue engineering applications.

  1. Autoradiography for iodine-125 seeds

    SciTech Connect

    Alberti, W.; Divoux, S. ); Pothmann, B.; Tabor, P. ); Hermann, K.P.; Harder, D. )

    1993-04-02

    To study the interior design of model 6702 and 6711 iodine-125 seeds, contact autoradiographs were performed using mammography film. Improved resolution was obtained using a pin-hole camera with a hole of 0.1 mm [times] 0.1 mm. With these techniques, qualitative determination of the relative activity distribution within each seed was possible. The number of the activated resin spheres and the positions of the centers of these spheres can be exactly determined. A model calculation shows that variations in the arrangement of the activated spheres within a seed have a moderate influence on the dose distribution at source distances below 10 mm. Knowing the exact source configuration may be useful when comparing dose calculations with measured data for model 6702 [sup 125]I seeds which are currently employed in ophthalmic plaque and implant therapy of other tumors. 16 refs., 5 figs., 2 tabs.

  2. Seed gum of Stryphnodendron barbatiman (Barbatimao)

    SciTech Connect

    Reicher, F.; Leitner, S.C.S.; Fontana, J.D.; Correa, J.B.C.; Sierakowski, M.R.

    1991-12-31

    Stryphnodendron barbatiman (barbatimao) is a native tree that is found throughout the {open_quotes}Cerrados,{close_quotes} a region of Central Brazil. Plant seeds, on water extraction, furnished 28 g% galactomannan (dry-weight basis), the monosaccharide composition of which (galactose to mannose ratio, 1.0:1.5) fits in the legume heteromannan group. This seed gum, after Sevag deproteinization, still retained 6 g% of associated protein and had a molecular weight of about 1.8 MD on gel filtration. A high intrinsic viscosity (1300 cP) was observed for the polysaccharide sample obtained after reflux of the crushed seeds in 80% aqueous methanol.

  3. Seed source, seed traits, and frugivore habits: Implications for dispersal quality of two sympatric primates.

    PubMed

    Benítez-Malvido, Julieta; González-Di Pierro, Ana Ma; Lombera, Rafael; Guillén, Susana; Estrada, Alejandro

    2014-06-11

    • Premise of the study: Frugivore selection of fruits and treatment of seeds together with seed deposition site are crucial for the population dynamics of vertebrate-dispersed plants. However, frugivore species may influence dispersal quality differently even when feeding on the same fruit species and, while animals disperse some seeds, others simply fall beneath the parent plant.• Methods: In southern Mexico, we investigated to see if within-species seed traits (i.e., length, width, weight, and volume) and germination success differed according to seed source. For five tropical tree species we obtained ingested seeds from two sources, howler monkey (Alouatta pigra) and spider monkey (Ateles geoffroyi) feces; and noningested seeds from two sources, the ground and tree crowns (with predispersed seeds used as control).• Key results: A principal components' analysis showed that traits of seeds ingested by howler monkeys differed from other sources while seeds ingested by spider monkeys were similar to noningested seeds. Howlers consumed on average the larger seeds in Ampelocera hottlei, Brosimum lactescens, and Dialium guianense. Both primate species consumed the smaller seeds in Spondias mombin, while no seed trait differences among seed sources were found in Spondias radlkoferi. For all five tree species, germination rate was greatest for seeds ingested by howler monkeys.• Conclusions: For the studied plant species, seed ingestion by howler monkeys confers higher dispersal quality than ingestion by spider monkeys or nondispersal. Dispersal services of both primate species, however, are not redundant and may contribute to germination heterogeneity within plant populations in tropical forests. PMID:24920763

  4. Yield components, leaf pigment contents, patterns of seed filling, dry matter, LAI and LAID of some safflower (Carthamus tinctorius L.) genotypes in Iran.

    PubMed

    Mokhtassi-Bidgoli, A; Akbari, Gh Al; Mirhadi, M J; Pazoki, A R; Soufizadeh, S

    2007-05-01

    In order to assess the genotypic variation among yield components and different physiological parameters and their relationships with safflower seed yield, six safflower genotypes were grown in Pakdasht, Iran in a randomized complete block design with four replications, during 2003-2004 growing season. Among the genotypes, chlorophyll a, chlorophyll b, chlorophyll a+b, total carotenoids contents, chlorophyll a/chlorophyll b ratio and Chlorophyll a+b/total cartenoids ratio ranged from 0.78 to 1.10, from 0.54 to 0.71, from 1.37 to 1.71, from 0.09 to 0.13 mg g(-1), from 1.33 to 1.68 and from 13.52 to 14.82, respectively. Negative relationships existed between seed yield and pigment contents. There were significant yield differences among genotypes and varied from 2452.60 to 3897.20 kg ha(-1). A diverse range of capitulum diameter (24.08-28.91 mm), seed weight/capitulum (1.18-2.04 g), number of seeds/m2 (8704.5-13165.4), number of capitula/plant (16.38-23.27), number of seeds/capitulum (35.65-41.90) and 1000-seed weight (29.94-50.60 g) was recorded. Genotypes differed in HI and the HI values ranged from 21.83% (LRK-262) to 29.62% (IL.111). In the studied set of 6 safflower genotypes, total biomass and LAI peaked around after full flowering and at the beginning of flowering, respectively. Zarghan-279 (with the greatest LAID) had 25% longer LAID than LRV.51.51 (with the lowest LAID). Differences among genotypes for rate of seed filling and effective seed filling duration were significant and differences in seed yield could be attributed to differences in the rate of seed filling. The results of this experiment indicate that physiological parameters including rate of seed filling, rapid leaf formation and expansion and delayed plant senescence are the characteristics of high-yielding safflower. Also, higher dry matter accumulation, HI, seed weight/capitulum, 1000-seed weight and capitulum diameter were found to be closely related to high-yield genotypes.

  5. Seed traits, fatty acid profile and genetic diversity assessment in Pongamia pinnata (L.) Pierre germplasm.

    PubMed

    Sharma, Shyam Sundar; Islam, Md Aminul; Malik, Anoop Anand; Kumar, Kamlesh; Negi, Madan Singh; Tripathi, Shashi Bhushan

    2016-04-01

    Phenotypic variation of important seed traits like seed length, seed breadth, seed thickness, 100 seed weight and seed oil content were recorded in a total of 157 collected accessions of Pongamia. Out of these, fatty acid profiles of 38 accessions selected based on their high and low oil content was analyzed. Fatty acid profile revealed high variability in stearic, oleic and linoleic acid which varied from 0.42 to 10.61 %, 34.34 to 74.58 %, and 7.00 to 31.28 % respectively. Variations in palmitic and linolenic acid were small. Iodine value, saponification number and cetane number (CN) of fatty acid methyl esters (FAME) of seed oil ranges from 186.99 to 201.25, 81.13 to 108.19 and 46.16 to 56.47 respectively. Fatty acid compositions, degree of unsaturation and CN are the important parameters, which are used to determine quality of FAME were used as biodiesel. Some of the Pongamia accessions identified were higher in oil content while some accessions showed higher degree of unsaturation and a few of them had CN values higher than 55. Genetic diversity analysis with six TE-AFLP primers generated a total of 334 bands out of which 174 (52.10 %) were polymorphic. The genetic similarity ranged from 0.11 to 0.47. These findings clearly showed high level of genetic diversity and all economically desirable traits were not present in a single genotype of Pongamia. All these traits could be selected from these CPTs and transfer to a single elite variety through selection and breeding programme and could be utilized for large scale multiplication and plantation to produce high quantity and quality biodiesel in future. PMID:27436911

  6. Microcontroller-based portable device for seeds moisture measurements

    NASA Astrophysics Data System (ADS)

    Iwaszko, Roman; Tarapata, Grzegorz; Weremczuk, Jerzy

    2006-10-01

    The paper describes construction of a new specialized hygrometer and dedicated applications for data acquisition and analyzing that can be used for seeds moisture measurements. To find the correlation between seeds water content and measurements results obtained from the device the weight method was applied. This paper shows preliminary results from tests of fully functional system allowing estimation in a very easy end fast way of the water content in germinating seeds without seeds destruction.

  7. Seed dimorphism, nutrients and salinity differentially affect seed traits of the desert halophyte Suaeda aralocaspica via multiple maternal effects

    PubMed Central

    2012-01-01

    Background Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects. Results Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient of variation (CV) for size of black seeds was higher than that of brown seeds. Seeds had the smallest CV at low nutrient and high salinity for plants from brown seeds and at low nutrient and low salinity for plants from black seeds. Low levels of nutrients increased size and germinability of black seeds but did not change the seed morph ratio or size and germinability of brown seeds. High levels of salinity decreased seed size but did not change the seed morph ratio. Seeds from high-salinity maternal plants had a higher germination percentage regardless of level of germination salinity. Conclusions Our study supports the multiple maternal effects hypothesis. Seed dimorphism, nutrient and salinity interacted in determining a range of seed traits of S. aralocaspica via bet-hedging and anticipatory maternal effects. This study highlights the importance of examining different maternal factors and various offspring traits in studies that estimate maternal effects on regeneration. PMID:23006315

  8. Sci—Fri PM: Topics — 02: Evaluation of Dosimetric Variations in Partial Breast Seed Implant (PBSI) due to Patient Arm Position (Up vs. Down)

    SciTech Connect

    Watt, E; Long, K; Husain, S; Meyer, T

    2014-08-15

    The planning for PBSI is done with the patient's ipsilateral arm raised, however, anatomical changes and variations are unavoidable as the patient resumes her daily activities, potentially resulting in significant deviations in implant geometry from the treatment plan. This study aims to quantify the impact of the ipsilateral arm position on the geometry and dosimetry of the implant at eight weeks, evaluated on post-plans using the MIM Symphony™ software (MIM Software, Cleveland, OH). The average dose metrics for the three patients treated at the TBCC thus far using rigid fusion and contour transfer for the arms up position were 76% for the CTV V100, 61% for the PTV V100, and 37% for the PTV V200; and for the arms down position 81% for the CTV V100, 64% for the PTV V100, and 42% for the PTV V200. Qualitative analysis of the post-implant CT for one of the three patients showed poor agreement between the seroma contour transferred from the pre-implant CT and the seroma visible on the post-implant CT. To obtain a clinically accurate plan for that patient, contour modifications were used, yielding improved dose metric averages for the arms-up position for all three patients of 87% for the CTV V100, 68% for the PTV V100, and 39% for the PTV V200. Overall, the data available shows that dosimetric parameters increase with the patient's arm down, both in terms of coverage and in terms of the hot spot, and accrual of more patients may confirm this in a larger population.

  9. Variation in Adult Plant Phenotypes and Partitioning among Seed and Stem-Borne Roots across Brachypodium distachyon Accessions to Exploit in Breeding Cereals for Well-Watered and Drought Environments.

    PubMed

    Chochois, Vincent; Vogel, John P; Rebetzke, Gregory J; Watt, Michelle

    2015-07-01

    Seedling roots enable plant establishment. Their small phenotypes are measured routinely. Adult root systems are relevant to yield and efficiency, but phenotyping is challenging. Root length exceeds the volume of most pots. Field studies measure partial adult root systems through coring or use seedling roots as adult surrogates. Here, we phenotyped 79 diverse lines of the small grass model Brachypodium distachyon to adults in 50-cm-long tubes of soil with irrigation; a subset of 16 lines was droughted. Variation was large (total biomass, ×8; total root length [TRL], ×10; and root mass ratio, ×6), repeatable, and attributable to genetic factors (heritabilities ranged from approximately 50% for root growth to 82% for partitioning phenotypes). Lines were dissected into seed-borne tissues (stem and primary seminal axile roots) and stem-borne tissues (tillers and coleoptile and leaf node axile roots) plus branch roots. All lines developed one seminal root that varied, with branch roots, from 31% to 90% of TRL in the well-watered condition. With drought, 100% of TRL was seminal, regardless of line because nodal roots were almost always inhibited in drying topsoil. Irrigation stimulated nodal roots depending on genotype. Shoot size and tillers correlated positively with roots with irrigation, but partitioning depended on genotype and was plastic with drought. Adult root systems of B. distachyon have genetic variation to exploit to increase cereal yields through genes associated with partitioning among roots and their responsiveness to irrigation. Whole-plant phenotypes could enhance gain for droughted environments because root and shoot traits are coselected.

  10. Variation in Adult Plant Phenotypes and Partitioning among Seed and Stem-Borne Roots across Brachypodium distachyon Accessions to Exploit in Breeding Cereals for Well-Watered and Drought Environments1[OPEN

    PubMed Central

    2015-01-01

    Seedling roots enable plant establishment. Their small phenotypes are measured routinely. Adult root systems are relevant to yield and efficiency, but phenotyping is challenging. Root length exceeds the volume of most pots. Field studies measure partial adult root systems through coring or use seedling roots as adult surrogates. Here, we phenotyped 79 diverse lines of the small grass model Brachypodium distachyon to adults in 50-cm-long tubes of soil with irrigation; a subset of 16 lines was droughted. Variation was large (total biomass, ×8; total root length [TRL], ×10; and root mass ratio, ×6), repeatable, and attributable to genetic factors (heritabilities ranged from approximately 50% for root growth to 82% for partitioning phenotypes). Lines were dissected into seed-borne tissues (stem and primary seminal axile roots) and stem-borne tissues (tillers and coleoptile and leaf node axile roots) plus branch roots. All lines developed one seminal root that varied, with branch roots, from 31% to 90% of TRL in the well-watered condition. With drought, 100% of TRL was seminal, regardless of line because nodal roots were almost always inhibited in drying topsoil. Irrigation stimulated nodal roots depending on genotype. Shoot size and tillers correlated positively with roots with irrigation, but partitioning depended on genotype and was plastic with drought. Adult root systems of B. distachyon have genetic variation to exploit to increase cereal yields through genes associated with partitioning among roots and their responsiveness to irrigation. Whole-plant phenotypes could enhance gain for droughted environments because root and shoot traits are coselected. PMID:25975834

  11. Variation in Adult Plant Phenotypes and Partitioning among Seed and Stem-Borne Roots across Brachypodium distachyon Accessions to Exploit in Breeding Cereals for Well-Watered and Drought Environments.

    PubMed

    Chochois, Vincent; Vogel, John P; Rebetzke, Gregory J; Watt, Michelle

    2015-07-01

    Seedling roots enable plant establishment. Their small phenotypes are measured routinely. Adult root systems are relevant to yield and efficiency, but phenotyping is challenging. Root length exceeds the volume of most pots. Field studies measure partial adult root systems through coring or use seedling roots as adult surrogates. Here, we phenotyped 79 diverse lines of the small grass model Brachypodium distachyon to adults in 50-cm-long tubes of soil with irrigation; a subset of 16 lines was droughted. Variation was large (total biomass, ×8; total root length [TRL], ×10; and root mass ratio, ×6), repeatable, and attributable to genetic factors (heritabilities ranged from approximately 50% for root growth to 82% for partitioning phenotypes). Lines were dissected into seed-borne tissues (stem and primary seminal axile roots) and stem-borne tissues (tillers and coleoptile and leaf node axile roots) plus branch roots. All lines developed one seminal root that varied, with branch roots, from 31% to 90% of TRL in the well-watered condition. With drought, 100% of TRL was seminal, regardless of line because nodal roots were almost always inhibited in drying topsoil. Irrigation stimulated nodal roots depending on genotype. Shoot size and tillers correlated positively with roots with irrigation, but partitioning depended on genotype and was plastic with drought. Adult root systems of B. distachyon have genetic variation to exploit to increase cereal yields through genes associated with partitioning among roots and their responsiveness to irrigation. Whole-plant phenotypes could enhance gain for droughted environments because root and shoot traits are coselected. PMID:25975834

  12. [Effects of storage time on quality of Desmodium styracifolium seeds].

    PubMed

    Yang, Quan; Tang, Xiao-min; Pan, Hai-yun; Mei, Ling-feng; Zhang, Chun-rong; Cheng, Xuan-xuan; Huang, Lu-qi

    2015-10-01

    The dynamic changes of germination percentage, germination potential, thousand-seed weight, antioxidase activity in Desmodium styracifolium seeds with different storage time were tested, and electrical conductivity, contents of soluble sugar, soluble protein, starch in seed leach liquor were also determined in order to reveal the mechanism of seed deterioration. The results as the following. (1) The germination percentage, germination potential and thousand-seed weight of D. styracifolium seeds declined, while the seed coat color darkened with the extension of storage time. (2) The activities of superoxide dismutase (SOD) and peroxidase (POD) decreased with the prolongation of storage period. The SOD activity declined fastest in 1,095-1,185 d of storage, while the POD activity declined significantly in 365-395 d of storage. (3) The electrical conductivity and the contents of soluble sugar, starch in seed leach liquor increased, while the content of soluble protein declined with the extension of storage time. (4) Correlation analysis indicated that the germination percentage, germination potential and thousand-seed weight of D. styracifolium seeds have a significantly positive correlation with SOD and POD activity, while have a significantly negative correlation with the electrical conductivity, contents of soluble sugar and starch. It can be concluded that during the storage of D. styracifolium seeds, physiological and biochemical changes including decrease in antioxidase activity, rise in electrical conductivity, degradation effluent of soluble sugar and starch, degradation of soluble protein were the main factors leading to the seed deterioration.

  13. UHPLC/HRMS analysis of African mango (Irvingia gabonensis) seeds, seed extracts, and African mango based dietary supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary Supplements based on extract from Irvingia gabonensis (African Mango, or AM) seeds are one of the popular herbal weight loss dietary supplements in the US market. The extract from the AM seeds is believed to be a natural and healthy way to lose weight and improve overall health. However, the...

  14. Weight Control

    MedlinePlus

    ... obese. Achieving a healthy weight can help you control your cholesterol, blood pressure and blood sugar. It ... use more calories than you eat. A weight-control strategy might include Choosing low-fat, low-calorie ...

  15. Body Weight

    MedlinePlus

    ... sign of a medical problem. Causes for sudden weight loss can include Thyroid problems Cancer Infectious diseases Digestive diseases Certain medicines Sudden weight gain can be due to medicines, thyroid problems, ...

  16. Changes in seed water status as characterized by NMR in developing soybean seed grown under moisture stress conditions

    SciTech Connect

    Krishnan, P. Singh, Ravender; Verma, A.P.S.; Joshi, D.K.; Singh, Sheoraj

    2014-02-21

    Highlights: • In developing soybean seeds, moisture stress resulted in more proportion of water to bound state. • These changes are further corroborated by concomitant changes in seed metabolites. • Thus there exists a moisture stress and development stage dependence of seed tissue water status. - Abstract: Changes in water status of developing seeds of Soybean (Glycine max L. Merrill.) grown under different moisture stress conditions were characterized by proton nuclear magnetic resonance (NMR)- spin–spin relaxation time (T{sub 2}). A comparison of the seed development characteristics, composition and physical properties indicated that, characteristics like seed weight, seed number/ear, rate of seed filling increased with development stages but decreased with moisture stress conditions. The NMR- spin–spin relaxation (T{sub 2}) component like bound water increased with seed maturation (40–50%) but decreased with moisture stress conditions (30–40%). The changes in seed water status to increasing levels of moisture stress and seed maturity indicates that moisture stress resulted in more proportion of water to bound state and intermediate state and less proportion of water in free-state. These changes are further corroborated by significant changes in protein and starch contents in seeds under high moisture stress treatments. Thus seed water status during its development is not only affected by development processes but also by moisture stress conditions. This study strongly indicated a clear moisture stress and development stage dependence of seed tissue water status in developing soybean seeds.

  17. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  18. Mapping variations in weight percent silica measured from multispectral thermal infrared imagery - Examples from the Hiller Mountains, Nevada, USA and Tres Virgenes-La Reforma, Baja California Sur, Mexico

    USGS Publications Warehouse

    Hook, S.J.; Dmochowski, J.E.; Howard, K.A.; Rowan, L.C.; Karlstrom, K.E.; Stock, J.M.

    2005-01-01

    Remotely sensed multispectral thermal infrared (8-13 ??m) images are increasingly being used to map variations in surface silicate mineralogy. These studies utilize the shift to longer wavelengths in the main spectral feature in minerals in this wavelength region (reststrahlen band) as the mineralogy changes from felsic to mafic. An approach is described for determining the amount of this shift and then using the shift with a reference curve, derived from laboratory data, to remotely determine the weight percent SiO2 of the surface. The approach has broad applicability to many study areas and can also be fine-tuned to give greater accuracy in a particular study area if field samples are available. The approach was assessed using airborne multispectral thermal infrared images from the Hiller Mountains, Nevada, USA and the Tres Virgenes-La Reforma, Baja California Sur, Mexico. Results indicate the general approach slightly overestimates the weight percent SiO2 of low silica rocks (e.g. basalt) and underestimates the weight percent SiO2 of high silica rocks (e.g. granite). Fine tuning the general approach with measurements from field samples provided good results for both areas with errors in the recovered weight percent SiO2 of a few percent. The map units identified by these techniques and traditional mapping at the Hiller Mountains demonstrate the continuity of the crystalline rocks from the Hiller Mountains southward to the White Hills supporting the idea that these ranges represent an essentially continuous footwall block below a regional detachment. Results from the Baja California data verify the most recent volcanism to be basaltic-andesite. ?? 2005 Elsevier Inc. All rights reserved.

  19. Seed deposition patterns and the survival of seeds and seedlings of the palm Euterpe edulis

    NASA Astrophysics Data System (ADS)

    Pizo, Marco A.; Simão, Isaac

    2001-08-01

    The seed deposition pattern created by a seed disperser is one of the components of the efficiency of a species as seed disperser, and ultimately may influence the recruitment of a plant species. In this study, we used the seeds of a bird-dispersed forest palm, Euterpe edulis, to investigate the effects of two distinct seed deposition patterns created by birds that defecate (clumped pattern) and regurgitate seeds (loose-clumped pattern) on the survival of seeds experimentally set in an E. edulis-rich site, and of seedlings grown under shade-house conditions. The study was conducted in the lowland forest of Parque Estadual Intervales, SE Brazil. Clumped and loose-clumped seeds were equally preyed upon by rodents and insects. Although clumped and isolated seedlings had the same root weight after 1 year, the isolated seedlings survived better and presented more developed shoots, suggesting intraspecific competition among clumped seedlings. Our results indicate that animals that deposit E. edulis seeds in faecal clumps (e.g. cracids, tapirs) are less efficient seed dispersers than those that regurgitate seeds individually (e.g. trogons, toucans). Intraspecific competition among seedlings growing from faecal clumps is a likely process preventing the occurrence of clumps of adult palms.

  20. [Study on seed quality test and quality standard of Pesudostellaria heterophylla].

    PubMed

    Xiao, Cheng-Hong; Zhou, Tao; Jiang, Wei-Ke; Chen, Min; Xiong, Hou-Xi; Liao, Ming-Wu

    2014-08-01

    Referring to the rules for agricultural seed testing (GB /T 3543-1995) issued by China, the test of sampling, seed purity, weight per 1 000 seeds, seed moisture, seed viability and germination rate had been studied for screening seed quality test methods of Pesudostellaria heterophylla. The seed quality from different collection areas was measured. The results showed that at least 6.5 g seeds should be sampled and passed through 10-mesh sieve for purity analysis. The weight of 1 000 seeds was determined by using the 500-seed method. The phenotypic observation and size measurement were used for authenticity testing. The seed moisture was determined under the higher temperature (130 ± 2) degrees C for 5 hours. The seeds were dipped into 0.2% TTC sustaining 1 hour at 40 degrees C, then the viability could be determined. The break dormancy seeds were cultured on sand at 10 degrees C. K cluster analysis was applied for the data analysis, the seed quality from different collection areas grading of P. Heterophylla was described as three grades. The seed quality of each grade should reach following requirements: for first grade seeds, germination rate ≥ 86%, 1 000-grain weight ≥ 2.59 g, purity ≥ 87%, moisture ≤ 13.1%; for second grade seeds, germination rate ≥ 70%, 1 000-grain weight ≥ 2.40 g, purity ≥ 77%, moisture ≤ 14.3%; for third grade seeds, germination rate ≥ 41%, 1 000-grain weight ≥ 2.29 g, purity ≥ 76%, moisture ≤ 15.8%. The seed testing methods for quality items of P. heterophylla had been initially established, as well as the primary P. heterophylla seed quality classification standard.

  1. What Are Chia Seeds?

    MedlinePlus

    ... Men For Women For Seniors What Are Chia Seeds? Published February 05, 2014 Print Email When you ... number of research participants. How to Eat Chia Seeds Chia seeds can be eaten raw or prepared ...

  2. Variation for canopy morphology in little bluestem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little bluestem, Schizachyrium scoparium (Michx.) Nash, is a native grass that has been shown to have high level of genetic variation for traits such as; biomass yield, disease resistance, plant height, leafiness, maturity, seed yield, and seed yield components. If high levels of genetic variation ...

  3. Bean Seed Imbibition.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1998-01-01

    Enables students to examine the time course for seed imbibition and the pressure generated by imbibing seeds. Provides background information, detailed procedures, and ideas for further investigation. (DDR)

  4. Biochemical properties of ricin in immature castor seed.

    PubMed

    Chakravartula, Srinivas V S; Guttarla, Nagaraj

    2008-05-10

    The biochemical properties of ricin at different stages of seed i.e. from immature to mature seed were studied. Hemagglutination, SDS-PAGE and UV-spectrometry studies showed total absence of RCA protein in the immature seed. Interestingly, ricin extract on SDS-PAGE showed only one protein band with a molecular weight of 29,000 dalton corresponding to the molecular weight of A chain of ricin. Our results have shown that at immature seed level only the toxic moiety of ricin (A chain) is being synthesized first and gradually the RCA and B chain of ricin. PMID:18569697

  5. Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)

    PubMed Central

    Tian, Yu; Guan, Bo; Zhou, Daowei; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method. PMID:25093210

  6. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    PubMed

    Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

  7. Phylogeny, Seed Trait, and Ecological Correlates of Seed Germination at the Community Level in a Degraded Sandy Grassland

    PubMed Central

    Wang, Zhengning; Wang, Lixin; Liu, Zhimin; Li, Yanjuan; Liu, Qingqing; Liu, Bo

    2016-01-01

    Seed germination strongly affects plant population growth and persistence, and it can be dramatically influenced by phylogeny, seed traits, and ecological factors. In this study, we examined the relationships among seed mass, seed shape, and germination percentage (GP), and assessed the extent to which phylogeny, seed traits (seed mass, shape, and color) and ecological factors (ecotype, life form, adult longevity, dispersal type, and onset of flowering) influence GP at the community level. All analyses were conducted on the log-transformed values of seed mass and arcsine square root-transformed values of GP. We found that seed mass and GP were significantly negatively correlated, whereas seed shape and GP were significantly positively correlated. The three major factors contributing to differences in GP were phylogeny, dispersal type, and seed shape (explained 5.8, 4.9, and 3.1% of the interspecific variations independently, respectively), but GP also influenced by seed mass and onset of flowering. Thus, GP was constrained not only by phylogeny but also by seed traits and ecological factors. These results indicated that GP is shaped by short-term selective pressures, and long-term phylogenetic constrains. We suggest that correlates of phylogeny, seed traits, and ecology should be taken into account in comparative studies on seed germination strategies. PMID:27799934

  8. Analysis of river health variation under the background of urbanization based on entropy weight and matter-element model: A case study in Huzhou City in the Yangtze River Delta, China.

    PubMed

    Pan, Guangbo; Xu, Youpeng; Yu, Zhihui; Song, Song; Zhang, Yuan

    2015-05-01

    Maintaining the health of the river ecosystem is an essential ecological and environmental guarantee for regional sustainable development and one of the basic objectives in water resource management. With the rapid development of urbanization, the river health situation is deteriorating, especially in urban areas. The river health evaluation is a complex process that involves various natural and social components; eight eco-hydrological indicators were selected to establish an evaluation system, and the variation of river health status under the background of urbanization was explored based on entropy weight and matter-element model. The comprehensive correlative degrees of urban river health of Huzhou City in 2001, 2006 and 2010 were then calculated. The results indicated that river health status of the study area was in the direction of pathological trend, and the impact of limiting factors (such as Shannon's diversity index and agroforestry output growth rate) played an important role in river health. The variation of maximum correlative degree could be classified into stationary status, deterioration status, deterioration-to-improvement status, and improvement-to-deterioration status. There was a severe deterioration situation of river health under the background of urbanization.

  9. Investigating Seed Longevity of Big Sagebrush (Artemisia tridentata)

    USGS Publications Warehouse

    Wijayratne, Upekala C.; Pyke, David A.

    2009-01-01

    from each site, as well as several environmental variables, were used to evaluate seed viability within the context of habitat variation. Initial viability of seeds used in the seed retrieval experiment was 81 and 92 percent for mountain and Wyoming big sagebrush, respectively. After remaining in the field for 24 months, buried Wyoming big sagebrush seeds retained 28-58 percent viability,11-23 percent of seeds under litter remained viable, and no seeds remained viable on the surface (estimates are 95-percent confidence intervals). The odds of remaining viable did not change from 12 to 24 months. However, after 24 months the odds of seeds beneath litter being viable decreased to 75 percent of the odds of viability at 12 months. Similar to Wyoming big sagebrush, buried seeds of mountain big sagebrush were 31-68 percent viable, seeds under litter retained 10-22 percent of their viability, and no surface seeds were viable after 24 months. Both subspecies of big sagebrush had some portion of seed that remained viable for more than one growing season provided they were buried or under litter. Although seeds beneath litter may remain viable in intact communities, seeds are susceptible to incineration during fires. Nine months after seed dispersal, seed bank estimates for Wyoming big sagebrush ranged from 19 to 49 viable seeds/m2 in litter samples and 19-57 viable seeds/m2 in soil samples (95-percent confidence interval). For mountain big sagebrush, estimates were 27-75 viable seeds/m2 in litter samples and 54-139 viable seeds/m2 in soil (95-percent confidence interval). The number of viable seeds present in the seed bank 9 months after seed dispersal was not significantly different from the number present immediately after seed dispersal. Seed viability was highest in mountain big sagebrush sites for seeds on the surface and beneath litter, but decreased after one season. Buried seeds of both subspecies were in equal abundances and may be insulated from the effect

  10. Seed morphology characteristics in relation to seed loss by water erosion in the Loess Plateau.

    PubMed

    Jiao, Juying; Han, Luyan; Jia, Yanfeng; Lei, Dong; Wang, Ning; Li, Linyu

    2013-01-01

    The role of water erosion on seed loss and on plant establishment and distribution is unknown on the Chinese Loess Plateau, which suffers serious soil erosion. The seed susceptibility of 16 local species to removal by water erosion from loess slopes was determined by rainfall simulation experiments. The experiments were performed on slopes with gradients of 10°, 15°, 20° and 25° for a 60-min duration at an intensity of 50 mm/h, 100 mm/h and 150 mm/h, respectively. The total seed removal rate obviously increased with rainfall intensity but did not obviously change with slope gradient, and the responses were varied among the species. The morphological characteristics affecting seed loss of the various species are quite different. Our experiments showed that the seed removal from some species are mainly due to seed weight, some species are mainly affected by seed shape, some are affected by appendage, some by surface structure, some by the comprehensive effects of the different morphological characteristics, while seeds having mucilage secretion are not easily moved by water erosion. We argued that the seed removal during water erosion can clearly effect seed redistribution and deposition, and consequently, species composition and vegetation spatial distribution.

  11. Weight Management

    MedlinePlus

    ... Quit Smoking Benefits of Quitting Health Effects of Smoking Secondhand Smoke Withdrawal Ways to Quit QuitGuide Pregnancy & Motherhood Pregnancy & Motherhood Before Your Baby is Born From Birth to 2 Years Quitting for Two SmokefreeMom Healthy Kids Parenting & ... Weight Management Weight Management ...

  12. Weight Watcher!

    ERIC Educational Resources Information Center

    Clarke, Doug

    1990-01-01

    The author, using a weight machine in an airport lounge, varies the machine's input parameters of height and gender to generate data sets of ideal weight. These data are later used at in-service workshops and in both primary and secondary classrooms to explore patterns and make predictions. (JJK)

  13. Cremation weights in east Tennessee.

    PubMed

    Bass, William M; Jantz, Richard L

    2004-09-01

    In spite of increasing number of cremations in the U.S., little is known about weights of cremated remains. This research was undertaken in order to add to the limited literature on cremains weights and to explore variation. Weights of cremated remains were obtained from the East Tennessee Crematorium. The sample consists of 151 males and 155 females. Age, sex, and race were obtained for each individual. Males are about 1000 g heavier than females. Both sexes lose weight with age, but females lose weight at about twice the rate of males. East Tennessee cremation weights were compared with those from Florida reported by Warren and Maples, and those from Southern California reported by Sonek. East Tennessee results were also compared with an earlier study on ash weight of anatomical human skeletons carried out by Trotter and Hixon. East Tennessee cremations weigh about 500 g more than the samples from Florida and California, and about the same as the earlier anatomical samples. We hypothesize that variation reflects variation in body weight and activity. This variation must be taken into account when cremation weights are at issue.

  14. The effect of high speed shearing on disaggregation and degradation of pectin from creeping fig seeds.

    PubMed

    Chen, Jun; Wu, Shuang-Shuang; Liang, Rui-Hong; Liu, Wei; Liu, Cheng-Mei; Shuai, Xi-Xiang; Wang, Zhao-Jun

    2014-12-15

    The effect of high speed shearing (HSS) on disaggregation and degradation of pectin from creeping fig seeds was investigated. It was found that disaggregation and degradation occurred during the whole shearing process. When pectin solution was sheared at 24,000 rpm for less than 8h, degradation happened but disaggregation was dominant during this period. After 8h, degradation became obvious, however, a small amount of aggregates remained even after 24h treatment, indicating that HSS may not eliminate aggregates efficiently. The presence of aggregates is one of the most probable causes for the inaccurate determination of molecular weight of pectin. A new method was proposed for calculating more accurately the molecular weight based on the change of the reducing sugar content and the variation of molecular weight. Determination of unsaturated uronide and FT-IR spectra analysis indicated that neither β-elimination nor demethoxylation occurred during the HSS, and no new functional group was formed during the HSS process.

  15. Birth Weight

    MedlinePlus

    ... with the placenta and substance abuse by the mother. Some low birth weight babies may be more at risk for certain health problems. Some may become sick in the first days of life or develop infections. Others may suffer ...

  16. Weight simulator

    NASA Technical Reports Server (NTRS)

    Howard, W. H.; Young, D. R.

    1972-01-01

    Device applies compressive force to bone to minimize loss of bone calcium during weightlessness or bedrest. Force is applied through weights, or hydraulic, pneumatic or electrically actuated devices. Device is lightweight and easy to maintain and operate.

  17. How the food supply harvestable by waders in the Wadden Sea depends on the variation in energy density, body weight, biomass, burying depth and behaviour of tidal-flat invertebrates

    NASA Astrophysics Data System (ADS)

    Zwarts, Leo; Wanink, Jan H.

    For several reasons, waders in the Wadden Sea face a large seasonal and annual variation in their food supply. Observations on a tidal flat in the Dutch Wadden Sea have shown that: - (1) The average energy density of ten invertebrate prey species varies between 21 and 23 kJ·g -1 AFDW. In Scrobicularia plana and Mya arenaria, but not in Macoma balthica, the energy density is 10% lower in winter than in summer. - (2) Depending on the species, body weights of prey of similar size are 30 to 60% lower in winter than in summer. - (3) The year-to-year fluctuation in standing-crop biomass is larger in some species than in others, the difference depending mainly on the frequency of successful recruitment. The overall biomass of the macrobenthos in winter is half of that in summer, but the timing of the peak biomass differs per species. - (4) The burying depth varies per species: Cerastoderma edule live just beneath the surface, while M. balthica, S. plana, M. arenaria, Arenicola marina and Nereis diversicolor bury more deeply and the majority of these prey live out of reach of the bird's bill. In all six species, burying depth increases with size. There is no seasonal variation in depth of C. edule and M. arenaria, but the four other species live at most shallow depth in early summer and most deeply in midwinter. Burying depths in winter vary from year to year, but are unrelated to temperature. Neither has temperature any effect on depth within months. For knot Calidris canutus feeding on M. balthica, the fluctuation in the accessible fraction was the main source of variation in the biomass of prey that is actually harvestable, i.e. the biomass of prey of suitable size that is accessible. Accordingly, the paper reviews the available data on the temporal variations in accessibility, detectability, ingestibility, digestibility and profitability of prey for waders. Only a small part of the prey is harvestable since many accessible prey are ignored because of their low

  18. Seasonal variation in dry weight and elemental composition of the early developmental stages of Petrolisthes laevigatus (Guérin, 1835) (Decapoda: Porcellanidae) in the Seno de Reloncaví, southern Chile

    NASA Astrophysics Data System (ADS)

    Gebauer, P.; Paschke, K.; Barría, A.; Anger, K.

    2013-03-01

    In the Seno de Reloncaví, southern Chile, seasonal changes in dry weight (DW) and elemental composition (CHN) were studied in embryo (initial embryonic stage), newly hatched zoeae, and newly settled megalopae of a porcelain crab, Petrolisthes laevigatus. Samples were taken throughout the seasons of egg laying (March-December), hatching (August-February), and settlement (October-February). Values of DW and CHN per embryo or larva, respectively, were consistently minimum in the middle of each season and maximum near its beginning and end. Patterns of seasonal variation in early embryonic biomass may thus be carried over to larvae at hatching and, possibly, to the settlement stage. Such carry-over effects may be selectively advantageous, as zoeae released at the beginning or near the end of the hatching season face conditions of poor planktonic food availability in combination with low winter temperatures or decreasing temperatures at the end of summer (enforcing long development duration). Hence, an enhanced female energy allocation into egg production may subsequently translate to enhanced yolk reserves remaining at hatching, allowing for a larval development under unfavourable winter conditions. In summer, by contrast, plankton productivity and temperatures are generally high, allowing for fast larval growth and development. This coincides with minimal biomass and energy contents both at hatching and settlement. In conclusion, our data suggest that seasonal patterns in the biomass of early developmental stages of P. laevigatus may reflect phenotypic variability as an adaptive response to predictable variations in environmental conditions, allowing this species to reproduce in temperate regions with marked seasonality in water temperature and plankton productivity.

  19. Associative Transcriptomics Study Dissects the Genetic Architecture of Seed Glucosinolate Content in Brassica napus

    PubMed Central

    Lu, Guangyuan; Harper, Andrea L.; Trick, Martin; Morgan, Colin; Fraser, Fiona; O'Neill, Carmel; Bancroft, Ian

    2014-01-01

    Breeding new varieties with low seed glucosinolate (GS) concentrations has long been a prime target in Brassica napus. In this study, a novel association mapping methodology termed ‘associative transcriptomics’ (AT) was applied to a panel of 101 B. napus lines to define genetic regions and also candidate genes controlling total seed GS contents. Over 100,000 informative single-nucleotide polymorphisms (SNPs) and gene expression markers (GEMs) were developed for AT analysis, which led to the identification of 10 SNP and 7 GEM association peaks. Within these peaks, 26 genes were inferred to be involved in GS biosynthesis. A weighted gene co-expression network analysis provided additional 40 candidate genes. The transcript abundance in leaves of two candidate genes, BnaA.GTR2a located on chromosome A2 and BnaC.HAG3b on C9, was correlated with seed GS content, explaining 18.8 and 16.8% of phenotypic variation, respectively. Resequencing of genomic regions revealed six new SNPs in BnaA.GTR2a and four insertions or deletions in BnaC.HAG3b. These deletion polymorphisms were then successfully converted into polymerase chain reaction–based diagnostic markers that can, due to high linkage disequilibrium observed in these regions of the genome, be used for marker-assisted breeding for low seed GS lines. PMID:25030463

  20. Associative transcriptomics study dissects the genetic architecture of seed glucosinolate content in Brassica napus.

    PubMed

    Lu, Guangyuan; Harper, Andrea L; Trick, Martin; Morgan, Colin; Fraser, Fiona; O'Neill, Carmel; Bancroft, Ian

    2014-12-01

    Breeding new varieties with low seed glucosinolate (GS) concentrations has long been a prime target in Brassica napus. In this study, a novel association mapping methodology termed 'associative transcriptomics' (AT) was applied to a panel of 101 B. napus lines to define genetic regions and also candidate genes controlling total seed GS contents. Over 100,000 informative single-nucleotide polymorphisms (SNPs) and gene expression markers (GEMs) were developed for AT analysis, which led to the identification of 10 SNP and 7 GEM association peaks. Within these peaks, 26 genes were inferred to be involved in GS biosynthesis. A weighted gene co-expression network analysis provided additional 40 candidate genes. The transcript abundance in leaves of two candidate genes, BnaA.GTR2a located on chromosome A2 and BnaC.HAG3b on C9, was correlated with seed GS content, explaining 18.8 and 16.8% of phenotypic variation, respectively. Resequencing of genomic regions revealed six new SNPs in BnaA.GTR2a and four insertions or deletions in BnaC.HAG3b. These deletion polymorphisms were then successfully converted into polymerase chain reaction-based diagnostic markers that can, due to high linkage disequilibrium observed in these regions of the genome, be used for marker-assisted breeding for low seed GS lines.

  1. Weighted EMPCA: Weighted Expectation Maximization Principal Component Analysis

    NASA Astrophysics Data System (ADS)

    Bailey, Stephen

    2016-09-01

    Weighted EMPCA performs principal component analysis (PCA) on noisy datasets with missing values. Estimates of the measurement error are used to weight the input data such that the resulting eigenvectors, when compared to classic PCA, are more sensitive to the true underlying signal variations rather than being pulled by heteroskedastic measurement noise. Missing data are simply limiting cases of weight = 0. The underlying algorithm is a noise weighted expectation maximization (EM) PCA, which has additional benefits of implementation speed and flexibility for smoothing eigenvectors to reduce the noise contribution.

  2. Spatial and temporal effects on seed dispersal and seed predation of Musa acuminata in southern Yunnan, China.

    PubMed

    Meng, Lingzeng; Gao, Xiuxia; Chen, Jin; Martin, Konrad

    2012-03-01

    Wild bananas are abundant in tropical areas and many ecologists have observed that the succession process is quicker following increased disturbance. This study was conducted to analyze animal-seed interactions and their effects on the seed fate of a wild banana species (Musa acuminata) in tropical southern Yunnan (China) through experiments considering spatial (site and habitat) and temporal (seasons) variation. The largest proportion of fruits (81%) was removed by frugivorous seed dispersers, especially by bats at nighttime. Only 13% of the fruits were removed by climbing seed predators (different species of rats). In the exclosure treatment, rodents accounted for a significantly higher total artificially exposed seed removal number than ants, but with spatial and temporal differences. The highest seed predation rate by rodents (70%) was found in forest with wild banana stands, corresponding with the highest rodent diversity (species numbers and abundance) among the habitat types. In contrast, the seed removal number by ants (57%) was highest in the open land habitats, but there was no close correlation with ant diversity. Seed removal numbers by ants were significantly higher in the dry compared to the rainy season, but rodent activity showed no differences between seasons. The overall results suggest that the largest proportion of seeds produced by wild banana are primarily dispersed by bats. Primary seed dispersal by bats at nighttime is essential for wild banana seeds to escape seed predation.

  3. Evaluation of the impacts of different nuclear DNA content in the hull, endosperm, and embryo of rice seeds on GM rice quantification.

    PubMed

    Liu, Donger; Shen, Jie; Yang, Litao; Zhang, Dabing

    2010-04-28

    Rice (Oryza sativa) is a main staple food in the world, and several genetically modified (GM) rice events have been approved for commercialization. To accurately quantify GM contents in rice derived products, we have evaluated the variation of seed DNA density and nuclear DNA content in the hull, endosperm, and embryo of rice seeds from 19 cultivars, as well as their impacts on GM rice quantification. Rice endosperm DNA accounts for 73.71% of total seed DNA, whereas the hull and embryo DNAs account for 3.98% and 22.31%, respectively. Two formulas were established to describe the relationship between GM content on the basis of weight ratio (GM(wt)%) and that on the basis of haploid genome copy number ratio (GM(hg)%) for the samples containing heterozygous GM rice seeds. These two equations were well confirmed in quantification of the heterozygous GM rice TT51-1 seeds containing the GM allele from a female parent or that from a male parent. This work is useful for accurate quantification of GM rice using reference materials containing the heterozygous GM rice seed powder.

  4. NEWER SDHI FUNGICIDES AND GRASSES: EFFECTS ON SEED YIELD AND DISEASE CONTROL.

    PubMed

    Rijckaert, G; Vanden Nest, T

    2015-01-01

    Grass seed crops (ryegrass), a minor crop in Belgium, should be managed more intensively and in an arable way, comparable with the intensive wheat culture. Even more important than higher seed yields are stable, higher yields over time, Integrated pest management (IPM) forms the framework around this intensification. Two similar seed production field trials--one with perennial ryegrass (Lolium perenne L.) and one with Italian ryegrass (Lolium multiflorum L.)--were conducted in 2014, dealing with 4 SDHI fungicides (bixafen, boscalid, fluxapyroxad and isopyrazam) that were compared with an untreated control and some reference treatments. There were four application times (stages): i.e. early stem elongation--BBCH 33 (T1), ear tips visible--BBCH 51 (T2), full ear, begin of flowering--BBCH 61 (T3) and end of flowering--BBCH 69 (T4). Except for the Italian ryegrass trial, only the last three stages were used. In the Italian ryegrass trial, which had only sporadic incidence of disease, all T3 treatments clearly increased seed yield compared with the untreated control, by 13% on average. For the T2 treatments only Fandango and Adexar clearly out yielded the control. The curative T4 treatment (Tilt + Corbel) tended to increase seed yield, but this was not significant. Seed yield differences could not be explained by variations in thousand seed weight (TSW), leaf withering and NDVI scores (crop reflectance). The disease pressure (crown rust) was very low before flowering, but stem rust developed strongly during the last 2 weeks before harvest of the perennial ryegrass trial. Yield responses were mostly pronounced at the T3 treatment. Except for Fandango and Horizon, all T3 treatments clearly increased yield in comparison with the untreated control, by 18.4% on average. The T4 treatment (Tilt + Corbel) could not repair the crop damage. Further seed yield data are discussed in relation to yield components, TSW, leaf withering and vegetation index (NDVI). An integrated

  5. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  6. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  7. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  8. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  9. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  10. Seed Treatment. Sale Publication 4076.

    ERIC Educational Resources Information Center

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide gives information about types of seeds that may require chemical protection against pests, seed treatment pesticide formulations, seed treatment methods, labeling treated seed, and safety and environmental precautions. (Author/BB)

  11. Seed harvesting by a generalist consumer is context-dependent: Interactive effects across multiple spatial scales

    USGS Publications Warehouse

    Ostoja, Steven M.; Schupp, Eugene W.; Klinger, Rob

    2013-01-01

    Granivore foraging decisions affect consumer success and determine the quantity and spatial pattern of seed survival. These decisions are influenced by environmental variation at spatial scales ranging from landscapes to local foraging patches. In a field experiment, the effects of seed patch variation across three spatial scales on seed removal by western harvester ants Pogonomyrmex occidentalis were evaluated. At the largest scale we assessed harvesting in different plant communities, at the intermediate scale we assessed harvesting at different distances from ant mounds, and at the smallest scale we assessed the effects of interactions among seed species in local seed neighborhoods on seed harvesting (i.e. resource–consumer interface). Selected seed species were presented alone (monospecific treatment) and in mixture with Bromus tectorum (cheatgrass; mixture treatment) at four distances from P. occidentalis mounds in adjacent intact sagebrush and non-native cheatgrass-dominated communities in the Great Basin, Utah, USA. Seed species differed in harvest, with B. tectorum being least preferred. Large and intermediate scale variation influenced harvest. More seeds were harvested in sagebrush than in cheatgrass-dominated communities (largest scale), and the quantity of seed harvested varied with distance from mounds (intermediate-scale), although the form of the distance effect differed between plant communities. At the smallest scale, seed neighborhood affected harvest, but the patterns differed among seed species considered. Ants harvested fewer seeds from mixed-seed neighborhoods than from monospecific neighborhoods, suggesting context dependence and potential associational resistance. Further, the effects of plant community and distance from mound on seed harvest in mixtures differed from their effects in monospecific treatments. Beyond the local seed neighborhood, selection of seed resources is better understood by simultaneously evaluating removal at

  12. Noninvasive diagnosis of seed viability using infrared thermography

    PubMed Central

    Kranner, Ilse; Kastberger, Gerald; Hartbauer, Manfred; Pritchard, Hugh W.

    2010-01-01

    Recent advances in the noninvasive analyses of plant metabolism include stress imaging techniques, mainly developed for vegetative tissues. We explored if infrared thermography can be used to predict whether a quiescent seed will germinate or die upon water uptake. Thermal profiles of viable, aged, and dead Pisum sativum seeds were recorded, and image analysis of 22,000 images per individual seed showed that infrared thermography can detect imbibition- and germination-associated biophysical and biochemical changes. These “thermal fingerprints” vary with viability in this species and in Triticum aestivum and Brassica napus seeds. Thermogenesis of the small individual B. napus seeds was at the limit of the technology. We developed a computer model of “virtual pea seeds,” that uses Monte Carlo simulation, based on the heat production of major seed storage compounds to unravel physico-chemical processes of thermogenesis. The simulation suggests that the cooling that dominates the early thermal profiles results from the dissolution of low molecular-weight carbohydrates. Moreover, the kinetics of the production of such “cooling” compounds over the following 100 h is dependent on seed viability. We also developed a deterministic tool that predicts in the first 3 hours of water uptake, when seeds can be redried and stored again, whether or not a pea seed will germinate. We believe that the early separation of individual, ungerminated seeds (live, aged, or dead) before destructive germination assessment creates unique opportunities for integrative studies on cell death, differentiation, and development. PMID:20133712

  13. Seed Proteomics"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteomic analysis of seeds encounters some specific problems that do not impinge on analyses of other plant cells, tissues, or organs. There are anatomic considerations. Seeds comprise the seed coat, the storage organ(s), and the embryonic axis. Are these to be studied individually or as a compo...

  14. Going to Seed.

    ERIC Educational Resources Information Center

    Powell, Richard R.

    1984-01-01

    Describes a unit on seeds designed to introduce students to their scientific and nutritional uses. Unit activities are easily done, employ a variety of process skills, and can be used at various grade levels. Suggests field trips to gather seeds, seed sprouting, and making cookies out of various whole grains. (JM)

  15. Needs of Seeds

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether students overgeneralize the needs of seeds by assuming they have the same needs as the adult plants…

  16. Two cytosolic glutamine synthetase isoforms play specific roles for seed germination and seed yield structure in Arabidopsis.

    PubMed

    Guan, M; Møller, I S; Schjoerring, J K

    2015-01-01

    Nitrogen (N) remobilization from reserves to sinks is essential for seedling establishment and seed production. Cytosolic glutamine synthetase (GS1) is up-regulated during both seed germination and seed filling in plants. However, the specific roles of the individual GS1 isogenes with respect to N remobilization, early seedling vigour, and final seed productivity are not known. In this study, impairment of seed germination and seedling establishment is demonstrated in the single knockout mutant gln1;2, and the double knockout mutant gln1;1:gln1;2. The negative effect of Gln1;2 deficiency was associated with reduced N remobilization from the cotyledons and could be fully alleviated by exogenous N supply. Following reproductive growth, both the single and double Gln1;2-knockout mutants showed decreased seed yield due to fewer siliques, less seeds per silique, and lower dry weight per seed. The gln1;1 single mutant had normal seed yield structure but primary root development during seed germination was reduced in the presence of external N. Gln1;2 promoter-green fluorescent protein constructs showed that Gln1;2 localizes to the vascular cells of roots, petals, and stamens. It is concluded that Gln1;2 plays an important role in N remobilization for both seedling establishment and seed production in Arabidopsis.

  17. Two cytosolic glutamine synthetase isoforms play specific roles for seed germination and seed yield structure in Arabidopsis

    PubMed Central

    Guan, M.; Møller, I. S.; Schjoerring, J. K.

    2015-01-01

    Nitrogen (N) remobilization from reserves to sinks is essential for seedling establishment and seed production. Cytosolic glutamine synthetase (GS1) is up-regulated during both seed germination and seed filling in plants. However, the specific roles of the individual GS1 isogenes with respect to N remobilization, early seedling vigour, and final seed productivity are not known. In this study, impairment of seed germination and seedling establishment is demonstrated in the single knockout mutant gln1;2, and the double knockout mutant gln1;1:gln1;2. The negative effect of Gln1;2 deficiency was associated with reduced N remobilization from the cotyledons and could be fully alleviated by exogenous N supply. Following reproductive growth, both the single and double Gln1;2-knockout mutants showed decreased seed yield due to fewer siliques, less seeds per silique, and lower dry weight per seed. The gln1;1 single mutant had normal seed yield structure but primary root development during seed germination was reduced in the presence of external N. Gln1;2 promoter–green fluorescent protein constructs showed that Gln1;2 localizes to the vascular cells of roots, petals, and stamens. It is concluded that Gln1;2 plays an important role in N remobilization for both seedling establishment and seed production in Arabidopsis. PMID:25316065

  18. The effects of ice storm on seed rain and seed limitation in an evergreen broad-leaved forest in east China

    NASA Astrophysics Data System (ADS)

    Du, Yanjun; Mi, Xiangcheng; Liu, Xiaojuan; Ma, Keping

    2012-02-01

    Extreme climatic events almost universally play a major role in influencing the composition and structure of plant and animal communities, and thus could influence seed production, seed dispersal and seedling recruitment. We explored the effects of ice storm damage on seed rain and seed limitation in a 24-ha permanent forest plot in an evergreen broad-leaved forest in east China. We compared seed production before and after the storm in 2008. We evaluated the following hypotheses: 1) seed production after the ice storm was less than that before the storm; 2) seed limitation after the storm was more severe than before the storm. The results showed that seeds from one species, Eurya muricata, dominated the seed rain after the storm, accounting for more than half of the total seeds. Post-ice storm seed production of species other than E. muricata was only one fifth of that before the storm. Seed production in the second year after the ice storm recovered to pre-storm levels. The results indicate large inter-specific variation in response to the ice storm. Disturbance caused by the ice storm greatly increased seed diversity. The Jaccard similarity of species before and after the ice storm was 58%. There was no significant difference in seed limitation or dispersal limitation before and after the storm, but there was a significant difference in source limitation. Neither seed limitation nor dispersal limitation was correlated with dispersal modes. Only source limitation for rodent dispersed species increased after the ice storm.

  19. Seed vigour and crop establishment: extending performance beyond adaptation.

    PubMed

    Finch-Savage, W E; Bassel, G W

    2016-02-01

    Seeds are central to crop production, human nutrition, and food security. A key component of the performance of crop seeds is the complex trait of seed vigour. Crop yield and resource use efficiency depend on successful plant establishment in the field, and it is the vigour of seeds that defines their ability to germinate and establish seedlings rapidly, uniformly, and robustly across diverse environmental conditions. Improving vigour to enhance the critical and yield-defining stage of crop establishment remains a primary objective of the agricultural industry and the seed/breeding companies that support it. Our knowledge of the regulation of seed germination has developed greatly in recent times, yet understanding of the basis of variation in vigour and therefore seed performance during the establishment of crops remains limited. Here we consider seed vigour at an ecophysiological, molecular, and biomechanical level. We discuss how some seed characteristics that serve as adaptive responses to the natural environment are not suitable for agriculture. Past domestication has provided incremental improvements, but further actively directed change is required to produce seeds with the characteristics required both now and in the future. We discuss ways in which basic plant science could be applied to enhance seed performance in crop production. PMID:26585226

  20. Viability of barley seeds after long-term exposure to outer side of international space station

    NASA Astrophysics Data System (ADS)

    Sugimoto, Manabu; Ishii, Makoto; Mori, Izumi C.; Elena, Shagimardanova; Gusev, Oleg A.; Kihara, Makoto; Hoki, Takehiro; Sychev, Vladimir N.; Levinskikh, Margarita A.; Novikova, Natalia D.; Grigoriev, Anatoly I.

    2011-09-01

    Barley seeds were exposed to outer space for 13 months in a vented metal container without a climate control system to assess the risk of physiological and genetic mutation during long-term storage in space. The space-stored seeds (S0 generation), with an 82% germination rate in 50 seeds, lost about 20% of their weight after the exposure. The germinated seeds showed normal growth, heading, and ripening. The harvested seeds (S1 generation) also germinated and reproduced (S2 generation) as did the ground-stored seeds. The culm length, ear length, number of seed, grain weight, and fertility of the plants from the space-stored seeds were not significantly different from those of the ground-stored seeds in each of the S0 and S1 generation. Furthermore, the S1 and S2 space-stored seeds respectively showed similar β-glucan content to those of the ground-stored seeds. Amplified fragment length polymorphism analysis with 16 primer combinations showed no specific fragment that appears or disappears significantly in the DNA isolated from the barley grown from the space-stored seeds. Though these data are derived from nine S0 space-stored seeds in a single exposure experiment, the results demonstrate the preservation of barley seeds in outer space for 13 months without phenotypic or genotypic changes and with healthy and vigorous growth in space.

  1. Identification and characterization of large DNA deletions affecting oil quality traits in soybean seeds through transcriptome sequencing analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the molecular and genetic mechanisms underlying variation in seed composition and contents among different genotypes is important for soybean oil quality improvement. We designed a bioinformatics approach to compare seed transcriptomes of 9 soybean genotypes varying in oil composition ...

  2. Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

    NASA Astrophysics Data System (ADS)

    Figuerola, Jordi; Charalambidou, Iris; Santamaria, Luis; Green, Andy J.

    2010-06-01

    Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser’s gut (i.e. the retention time, survival and germination of ingested seeds). A combination of experiments with captive waterbirds and aquatic plant seeds was used to analyse the following: (a) the effects of inter- and intra-specific variation in seed size and duck species on seed retention time in the gut and (b) the relationship between retention time and the percent germination and germination rates of seeds. Among the three Scirpus species used, those with smaller seeds showed higher survival after ingestion by birds and longer retention times inside their guts than those with larger seeds. For Potamogeton pectinatus, only seeds from the smaller size class (<8 mg) survived ingestion. Retention time affected the percent germination and germination rate of Scirpus seeds but in a manner that varied for the different plant and bird species studied. We recorded both linear and non-linear effects of retention time on percent germination. In addition, germination rate was positively correlated with retention time in Scirpus litoralis but negatively correlated in Scirpus lacustris. Small seed size can favour dispersal over larger distances. However, the effects of retention time on percent germination can modify the seed shadows produced by birds due to higher percent germination of seeds retained for short or intermediate periods. The changes in dispersal quality associated with dispersal distance (which is expected to be positively related to retention time) will affect the probability of seedling establishment over longer distances and, thus, the spatial characteristics of the effective seed shadow.

  3. Scuba Weights

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Attitude Adjuster is a system for weight repositioning corresponding to a SCUBA diver's changing positions. Compact tubes on the diver's air tank permit controlled movement of lead balls within the Adjuster, automatically repositioning when the diver changes position. Manufactured by Think Tank Technologies, the system is light and small, reducing drag and energy requirements and contributing to lower air consumption. The Mid-Continent Technology Transfer Center helped the company with both technical and business information and arranged for the testing at Marshall Space Flight Center's Weightlessness Environmental Training Facility for astronauts.

  4. A herbivory-induced increase in the proportion of floating seeds in an invasive plant

    NASA Astrophysics Data System (ADS)

    Fukano, Yuya; Hirayama, Hiroyuki; Tanaka, Koichi

    2014-04-01

    It is important to determine the factors prompting seed dispersal because for plant species seed dispersal is the only opportunity to disperse into a new habitat. Previous studies showed that the maternal stress, such as high density and low nutrient levels, induces the adaptive plastic increase of the dispersal ability in seed heteromorphic plants. In this study, we examined whether herbivory can change the relative proportion of dispersal-related seed heteromorphism (floating or non floating seeds) in an invasive weed Ambrosia artemisiifolia. Because A. artemisiifolia often distributes in the riparian habitat, floating seeds might contribute to the long distance dispersal by hydrochory. Floating ability and seed weight were compared between plants damaged by a specialist herbivore Ophraella communa and undamaged plants. The damaged plants produced lighter and more likely floating seeds than the undamaged plants. However, multi-regression analysis revealed that the probability of floating was affected by seed weight but was not affected by herbivore treatment (damaged vs. undamaged plants). These results suggest that the increased proportion of floating seeds was not a direct response to the herbivore signal but an indirect response through the herbivore's effect on the reduction of seed weight. Plants damaged by herbivores might not only decrease seed production and quality but also increase the dispersal ability. These responses in dispersal ability against the herbivores might contribute to the spread of invasive plants.

  5. Paternal contribution to birth weight

    PubMed Central

    Magnus, P; Gjessing, H; Skrondal, A; Skjarven, R

    2001-01-01

    STUDY OBJECTIVE—Understanding causes of variation in birth weight has been limited by lack of sufficient sets of data that include paternal birth weight. The objective was to estimate risks of low birth weight dependent on parental birth weights and to estimate father-mother-offspring correlations for birth weight to explain the variability in birth weight in terms of effects of genes and environmental factors.
DESIGN—A family design, using trios of father-mother-firstborn child.
SETTING—The complete birth population in Norway 1967-98.
PARTICIPANTS—67 795 families.
MAIN RESULTS—The birth weight correlations were 0.226 for mother-child and 0.126 for father-child. The spousal correlation was low, 0.020. The relative risk of low birth weight in the first born child was 8.2 if both parents were low birth weight themselves, with both parents being above 4 kg as the reference. The estimate of heritability is about 0.25 for birth weight, under the assumption that cultural transmission on the paternal side has no effect on offspring prenatal growth.
CONCLUSIONS—Paternal birth weight is a significant and independent predictor of low birth weight in offspring. The estimate of the heritability of birth weight in this study is lower than previously estimated from data within one generation in the Norwegian population.


Keywords: birth weight; genes; paternal effects PMID:11707480

  6. Seed Dispersal Anachronisms: Rethinking the Fruits Extinct Megafauna Ate

    PubMed Central

    Guimarães, Paulo R.; Galetti, Mauro; Jordano, Pedro

    2008-01-01

    Background Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals >103 kg), yet these dispersers were extinct in South America 10–15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. Methodology/Principal Findings We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4–10 cm in diameter with up to five large seeds, and fruits >10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size) with either a single or few (<3 seeds) extremely large seeds or many small seeds (usually >100 seeds). Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. Conclusions/Significance Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal by relying on frugivores able to disperse enormous seed loads over long-distances. Present-day seed dispersal by scatter-hoarding rodents, introduced livestock, runoff, flooding, gravity, and human-mediated dispersal allowed survival of megafauna-dependent fruit species after extinction of the major seed dispersers. Megafauna extinction had several potential consequences, such as a scale shift reducing the seed dispersal distances, increasingly clumped spatial patterns, reduced geographic ranges and limited genetic

  7. Lipid profiling of developing Jatropha curcas L. seeds using (1)H NMR spectroscopy.

    PubMed

    Annarao, Sanjay; Sidhu, O P; Roy, Raja; Tuli, Rakesh; Khetrapal, C L

    2008-12-01

    Seed development in Jatropha curcas L. was studied with respect to phenology, oil content, lipid profile and concentration of sterols. Seeds were collected at various stages of development starting from one week after fertilization and in an interval of five days thereafter till maturity. These were classified as stage I to stage VII. Moisture content of the seeds ranged from 8.8 to 90.3%; the lowest in mature seeds in stage VII and highest in stage I. The seed area increased as the seed grew from stage I to stage VI (0.2-10.2mm(2) per seed), however, the seed area shrunk at stage VII. Increase in seed area corresponded to increase in fresh weight of the seeds. (1)H NMR spectroscopy of hexane extracts made at different stages of seed development revealed the presence of free fatty acids (FFA), methyl esters of fatty acids (FAME) and triglycerol esters (TAG), along with small quantity of sterols. The young seeds synthesized predominantly polar lipids. Lipid synthesis was noticed nearly three weeks after fertilization. From the fourth week the seeds actively synthesized TAG. Stage III is a turning point in seed development since at this stage, the concentration of sterols decreased to negligible, there was very little FAME formation, accumulation of TAG increased substantially, and there was a sudden decrease in FFA concentration. The findings can be helpful in understanding the biosynthesis and in efforts to improve biosynthesis of TAG and reduce FFA content in the mature seeds. PMID:18534845

  8. Effects of germination time on seed morph ratio in a seed-dimorphic species and possible ecological significance

    PubMed Central

    Yang, Fan; Baskin, Jerry M.; Baskin, Carol C.; Yang, Xuejun; Cao, Dechang; Huang, Zhenying

    2015-01-01

    Background and Aims Diaspores of heteromorphic species may germinate at different times due to distinct dormancy-breaking and germination requirements, and this difference can influence life history traits. The primary aim of this study was to determine the effect of germination time of the two seed morphs of Suaeda corniculata subsp. mongolica on life history traits of the offspring. Methods Germinated brown and black seeds were sown on the 20th of each month from April to September in a simulated but near-natural habitat of the species. Phenological and vegetative traits of the maternal plants, and number, size and germination percentage of the offspring were determined. Key Results Germinated seeds sown late in the year produced smaller plants that had a higher proportion of non-dormant brown than dormant black seeds, and these brown seeds were larger than those produced by germinated seeds sown early in the year. The length of the seedling stage for brown seeds was shorter than that for black seeds, and the root/shoot ratio and reproductive allocation of plants from brown seeds were more variable than they were for plants from black seeds. Late-germinating brown seeds produced larger plants than late-germinating black seeds. Conclusions Altering the proportion of the two seed types in response to germination timing can help alleviate the adverse effects of delayed germination. The flexible strategy of a species, such as S. corniculata, that produces different proportions of dimorphic seeds in response to variation in germination timing may favour the maintenance and regeneration of the population in its unpredictable environment. PMID:25395107

  9. Seed preferences by rodents in the agri-environment and implications for biological weed control.

    PubMed

    Fischer, Christina; Türke, Manfred

    2016-08-01

    Post-dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. However, their potential to disperse seeds endozoochorously is largely unknown. We exposed seeds of arable plant species with different seed traits (seed weight, nutrient content) and different Red List status in an experimental rye field and assessed seed removal by rodents. In a complementary laboratory experiment, consumption rates, feeding preferences, and potential endozoochory by two vole species (Microtus arvalis and Myodes glareolus) were tested. Seed consumption by rodents after 24 h was 35% in the field and 90% in the laboratory. Both vole species preferred nutrient-rich over nutrient-poor seeds and M. glareolus further preferred light over heavy seeds and seeds of common over those of endangered plants. Endozoochory by voles could be neglected for all tested plant species as no seeds germinated, and only few intact seeds could be retrieved from feces. Synthesis and applications. Our results suggest that voles can provide regulating services in agricultural landscapes by depleting the seed shadow of weeds, rather than facilitating plant recruitment by endozoochory. In the laboratory, endangered arable plants were less preferred by voles than noxious weeds, and thus, our results provide implications for seed choice in restoration approaches. However, other factors such as seed and predator densities need to be taken into account to reliably predict the impact of rodents on the seed fate of arable plants. PMID:27547355

  10. Physiology of Oil Seeds

    PubMed Central

    Ketring, D. L.; Morgan, P. W.

    1971-01-01

    Germination, ethylene production, and carbon dioxide production by dormant Virginia-type peanuts were determined during treatments with plant growth regulators. Kinetin, benzylaminopurine, and 2-chloroethylphosphonic acid induced extensive germination above the water controls. Benzylaminopurine and 2-chloroethylphosphonic acid increased the germination of the more dormant basal seeds to a larger extent above the controls than the less dormant apical seeds. Coumarin induced a slight stimulation of germination while abscisic acid, 2,4-dichlorophenoxyacetic acid, and succinic acid 2,2-dimethylhydrazide did not stimulate germination above the controls. In addition to stimulating germination, the cytokinins also stimulated ethylene production by the seeds. In the case of benzylaminopurine, where the more dormant basal seeds were stimulated to germinate above the control to a larger extent than the less dormant apical seeds, correspondingly more ethylene production was induced in the basal seeds. However, the opposite was true of kinetin for both germination and ethylene production. When germination was extensively stimulated by the cytokinins, maximal ethylene and carbon dioxide evolution occurred at 24 and 72 hours, respectively. Abscisic acid inhibited ethylene production and germinaton of the seeds while carbon dioxide evolution was comparatively high. The crucial physiological event for germination of dormant peanut seeds was enhancement of ethylene production by the seeds. PMID:16657647

  11. A role for seed storage proteins in Arabidopsis seed longevity.

    PubMed

    Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

    2015-10-01

    Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation.

  12. [Seed growth characteristics of Ginkgo biloba and its physiological change].

    PubMed

    Wang, J; Wang, J; Xin, X

    2000-08-01

    The length, width, volume and weight of Ginkgo biloba seed were measured, and the concentrations of water, sugars, fatty acids and amino acids in seed growth process were analyzed. A typical "S" seed growth curve was found, and the length, width, volume, weight and absolute water content all showed the similar changes during growing period. With the growing of ssed, the concentrations of physiological substances in seeds showed regular changes and had their own characteristics. The total amount of sugars appeared to be an increasing trend at the later stage of seed growth, indicating that sugars are the main nutrition substance accumulated in seeds. The concentrations of various substances in matured seeds were starch 8.4%, glucose 6.7%, fructose 4.2%, polysaccharide 0.02%, disaccharide 0.01%, myristic acid 10.6%, palmitic acid 4.1%, flax acid 2.4%, stearic acid 1.9%, oleic acid 1.1%, and linoleic acid 0.4%. Fifteen types of free amino acids were detected in matured seeds, with total content of 1.56 g.100 g-1FW. Among them, lysine aspartic acid, alanine, arginine, histidine, glutamic acid, and isoleucine were dominant, and their concentrations were 0.287%, 0.163%, 0.136%, 0.133%, 0.123%, 0.115%, 0.095%, respectively.

  13. Synchrony between fruit maturation and effective dispersers' foraging activity increases seed protection against seed predators

    PubMed Central

    Boulay, Raphaël; Carro, Francisco; Soriguer, Ramón C; Cerdá, Xim

    2007-01-01

    The evolution of pollination and seed dispersal mutualisms is conditioned by the spatial and temporal co-occurrence of animals and plants. In the present study we explore the timing of seed release of a myrmecochorous plant (Helleborus foetidus) and ant activity in two populations in southern Spain during 2 consecutive years. The results indicate that fruit dehiscence and seed shedding occur mostly in the morning and correspond to the period of maximum foraging activity of the most effective ant dispersers. By contrast, ant species that do not transport seeds and/or that do not abound near the plants are active either before or after H. foetidus diaspores are released. Experimental analysis of diet preference for three kinds of food shows that effective ant dispersers are mostly scavengers that readily feed on insect corpses and sugars. Artificial seed depots suggest that seeds deposited on the ground out of the natural daily time window of diaspore releasing are not removed by ants and suffer strong predation by nocturnal rodents Apodemus sylvaticus. Nevertheless, important inter-annual variations in rodent populations cast doubts on their real importance as selection agents. We argue that traits allowing synchrony between seed presentation and effective partners may constitute a crucial pre-adaptation for the evolution of plant–animal mutualisms involving numerous animal partners. PMID:17698486

  14. The perspective effects of various seed coating substances on rice seed variety Khao DAWK Mali 105 storability I: the case study of physiological properties.

    PubMed

    Thobunluepop, P; Pawelzik, E; Vearasilp, S

    2008-10-01

    This study aimed to evaluate the perspective changes of several physiological performances of rice seeds cv. KDML 105 which were coated with various seed coating substances [chemical fungicide, captan (CA) and biological coating polymers; chitosan-lignosulphonate polymer (CL) and eugenol incorporated into chitosan-lignosulphonate polymer (E + CL)] during storage (12 months). CA significantly increased seed moisture content and seed water activity through out the storage period. The qualities and viability of the seeds were seriously declined by this treatment. Moreover, CA inhibited the shoot and root development, seedling dry weight accumulation, delayed the seed germination and seedling growth rate. CA treated seeds were susceptible to stress conditions that declined the seed germination potential under cold, high moisture and temperature stress conditions. Nevertheless, CL and E + CL coating polymer could maintain seed storability, which significantly improved seed germination and seedling performances. These improvements were attributed to maintain the nutritive reserve and dehydrogenase activity in seeds. Moreover, the biological seed treatment stimulated the embryo growth and so speeding up the seedling emergence when compared untreated seeds.

  15. Pollen- and Seed-Mediated Transgene Flow in Commercial Cotton Seed Production Fields

    PubMed Central

    Heuberger, Shannon; Ellers-Kirk, Christa; Tabashnik, Bruce E.; Carrière, Yves

    2010-01-01

    Background Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt) cotton is planted on millions of hectares annually and is a potential source of transgene flow. Methodology/Principal Findings Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L.) seed production fields (some transgenic for herbicide resistance, some not) for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. Conclusions/Significance A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow. PMID:21152426

  16. Overexpression of sinapine esterase BnSCE3 in oilseed rape seeds triggers global changes in seed metabolism.

    PubMed

    Clauss, Kathleen; von Roepenack-Lahaye, Edda; Böttcher, Christoph; Roth, Mary R; Welti, Ruth; Erban, Alexander; Kopka, Joachim; Scheel, Dierk; Milkowski, Carsten; Strack, Dieter

    2011-03-01

    Sinapine (O-sinapoylcholine) is the predominant phenolic compound in a complex group of sinapate esters in seeds of oilseed rape (Brassica napus). Sinapine has antinutritive activity and prevents the use of seed protein for food and feed. A strategy was developed to lower its content in seeds by expressing an enzyme that hydrolyzes sinapine in developing rape seeds. During early stages of seedling development, a sinapine esterase (BnSCE3) hydrolyzes sinapine, releasing choline and sinapate. A portion of choline enters the phospholipid metabolism, and sinapate is routed via 1-O-sinapoyl-β-glucose into sinapoylmalate. Transgenic oilseed rape lines were generated expressing BnSCE3 under the control of a seed-specific promoter. Two distinct single-copy transgene insertion lines were isolated and propagated to generate homozygous lines, which were subjected to comprehensive phenotyping. Sinapine levels of transgenic seeds were less than 5% of wild-type levels, whereas choline levels were increased. Weight, size, and water content of transgenic seeds were significantly higher than those of wild-type seeds. Seed quality parameters, such as fiber and glucosinolate levels, and agronomically important traits, such as oil and protein contents, differed only slightly, except that amounts of hemicellulose and cellulose were about 30% higher in transgenic compared with wild-type seeds. Electron microscopic examination revealed that a fraction of the transgenic seeds had morphological alterations, characterized by large cavities near the embryonic tissue. Transgenic seedlings were larger than wild-type seedlings, and young seedlings exhibited longer hypocotyls. Examination of metabolic profiles of transgenic seeds indicated that besides suppression of sinapine accumulation, there were other dramatic differences in primary and secondary metabolism. Mapping of these changes onto metabolic pathways revealed global effects of the transgenic BnSCE3 expression on seed metabolism. PMID

  17. A quick SEED tutorial

    USGS Publications Warehouse

    Ringler, Adam; Evans, John R.

    2015-01-01

    A number of different government-funded seismic data centers offer free open-access data (e.g., U.S. Geological Survey, National Earthquake Information Center, the Incorporated Research Institutions for Seismology (IRIS), and Data Management System), which can be freely downloaded and shared among different members of the community (Lay, 2009). To efficiently share data, it is important that different data providers follow a common format. The Standard for the Exchange of Earthquake Data (SEED) provides one such format for storing seismic and other geophysical data. The SEED format is widely used in earthquake seismology; however, SEED and its structure can be difficult for many first-time users (ourselves included). Below is a quick tutorial that outlines the basic structure of SEED format. This write-up is in no way intended to replace the comprehensive SEED manual (Ahern et al., 2009), and instead of going into the details of any specific part of the SEED format we refer the reader to the manual for additional details. The goal of this write-up is to succinctly explain the basic structure of SEED format as well as the associated jargon, as most commonly used now, in a colloquial way so that novice users of SEED can become more familiar with the format and its application quickly. Our goal is to give the reader the necessary background so that when problems or questions about SEED format arise they will have some understanding of where they should look for more details or from where the problem might be stemming. As a secondary goal, we hope to help the reader become familiar with the SEED manual (Ahern et al., 2009), which contains detailed information about all aspects of the SEED format.

  18. Dependence of Dandelion (Taraxacum officinale Wigg.) Seed Reproduction Indices on Intensity of Motor Traffic Pollution.

    PubMed

    Erofeeva, Elena A

    2014-12-01

    Dandelion (Taraxacum officinale Wigg.) seed reproduction indices such as the total number of seeds, the number of normally developed seeds and underdeveloped seeds per anthodium, and seed weight are suggested to assess the level of environmental pollution (bioindication). However, the non-monotonic dose-response dependences (hormesis and paradoxical effects) of these indices are insufficiently explored upon exposure to pollution. We studied the dependence of some T. officinale seed reproduction indices on intensity of motor traffic pollution in wide range of values over 2 years of observation. In 2010, the increase in traffic intensity induced a monotonic increase in the total seed number and the number of normally developed seeds. Besides, motor traffic pollution decreased the number of undeveloped seeds and seed weight in comparison with the control. In 2011, for all studied T. officinale indices except seed weight, complicated non-monotonic dependences on traffic intensity were found that could be attributed to paradoxical effects. It is hypothesised that the significant differences in the studied dependencies in 2010-2011 were caused by changes in weather conditions because traffic intensity did not differ significantly between the two observation years. PMID:25552956

  19. Dependence of Dandelion (Taraxacum officinale Wigg.) Seed Reproduction Indices on Intensity of Motor Traffic Pollution.

    PubMed

    Erofeeva, Elena A

    2014-12-01

    Dandelion (Taraxacum officinale Wigg.) seed reproduction indices such as the total number of seeds, the number of normally developed seeds and underdeveloped seeds per anthodium, and seed weight are suggested to assess the level of environmental pollution (bioindication). However, the non-monotonic dose-response dependences (hormesis and paradoxical effects) of these indices are insufficiently explored upon exposure to pollution. We studied the dependence of some T. officinale seed reproduction indices on intensity of motor traffic pollution in wide range of values over 2 years of observation. In 2010, the increase in traffic intensity induced a monotonic increase in the total seed number and the number of normally developed seeds. Besides, motor traffic pollution decreased the number of undeveloped seeds and seed weight in comparison with the control. In 2011, for all studied T. officinale indices except seed weight, complicated non-monotonic dependences on traffic intensity were found that could be attributed to paradoxical effects. It is hypothesised that the significant differences in the studied dependencies in 2010-2011 were caused by changes in weather conditions because traffic intensity did not differ significantly between the two observation years.

  20. Host use and resource sharing by fruit/seed-infesting insects on Schoepfia schreberi (Olacaceae).

    PubMed

    López-Ortega, Maurilio; Pérez-Rodríguez, Paulino; Rojas, Julio C; Soto Hernández, R Marcos; López-Mata, Lauro; Rico-Gray, Víctor

    2013-04-01

    The interactions between the fruit fly Anastrepha spatulata Stone (Diptera: Tephritidae) and two species of moths, the gelechiid Coleotechnites sp. and an unidentified tortricid species, were examined on their effects on seed production in terms of their exploitation within fruits of Schoepfia schreberi J.F. Gmel (Santalales: Olacaceae). The study was carried out in three experimental sites during 3 yr. Under conditions of abundant fruit, A. spatulata was the dominant exploiter at the population level, as shown by its ability to infest the largest number of fruits of the three herbivores and substantially displace its moth competitors. In a separate experiment, when resource-partitioning species were excluded, A. spatulata infested twice as many fruits as the two moth species (44.3%). Field observations examined the ability of A. spatulata to locate suitable fruits. We found that, the variation in fruit characters influenced fruit suitability in relation to its size (4.1261 ± 0.0272 mm [mean ± SE]) and weight (0.0618 ± 0.0005 mg [mean ± SE]). Uninfested fruits produce viable seed but the interaction of all species (exploiting for the fruits) led to limited seed formation. PMID:23575012

  1. Inhibition of testosterone-induced hyperplasia of the prostate of sprague-dawley rats by pumpkin seed oil.

    PubMed

    Gossell-Williams, M; Davis, A; O'Connor, N

    2006-01-01

    The oil from the pumpkin (Cucurbita pepo) seed is claimed to be useful in the management of benign prostatic hyperplasia. This investigation seeks to examine the effect of pumpkin seed oil on testosterone-induced hyperplasia of the prostate of rats. Hyperplasia was induced by subcutaneous administration of testosterone (0.3 mg/100 g of body weight) for 20 days. Simultaneous oral administration of either pumpkin seed oil (2.0 and 4.0 mg/100 g of body weight) or corn oil (vehicle) was also given for 20 days. The weights of the rats were recorded weekly, and the influence of testosterone and pumpkin seed oil on the weight gain of the rats was examined. On day 21, rats were sacrificed, and the prostate was removed, cleaned, and weighed. The prostate size ratio (prostate weight/rat body weight) was then calculated. Neither testosterone nor pumpkin seed oil had any significant influence on the weight gain of the rats. Testosterone significantly increased prostate size ratio (P < .05), and this induced increase was inhibited in rats fed with pumpkin seed oil at 2.0 mg/100 g of body weight. The protective effect of pumpkin seed oil was significant at the higher pumpkin seed oil dose (P < .02). We conclude pumpkin seed oil can inhibit testosterone-induced hyperplasia of the prostate and therefore may be beneficial in the management of benign prostatic hyperplasia.

  2. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  3. Relative seed and fruit toxicity of the Australian cycads Macrozamia miquelii and Cycas ophiolitica: further evidence for a megafaunal seed dispersal syndrome in cycads, and its possible antiquity.

    PubMed

    Hall, J A; Walter, G H

    2014-08-01

    An apparent contradiction in the ecology of cycad plants is that their seeds are known to be highly poisonous, and yet they seem well adapted for seed dispersal by animals, as shown by their visually conspicuous seed cones and large seeds presented within a brightly colored fleshy "fruit" of sarcotesta. We tested if this sarcotesta could function as a reward for cycad seed dispersal fauna, by establishing if the toxic compound cycasin, known from the seeds, is absent from the sarcotesta. The Australian cycads Macrozamia miquelii and Cycas ophiolitica were tested (N = 10 individuals per species) using gas chromatography / mass spectrometry. Cycasin was detected at 0.34 % (fresh weight) in seed endosperm of M. miquelii and 0.28 % (fresh weight) in seed endosperm of C. ophiolitica. Cycasin was absent from the sarcotesta of the same propagules (none detected in the case of M. miquelii, and trace quantities detected in sarcotesta of only four of the ten C. ophiolitica propagules). This laboratory finding was supported by field observations of native animals eating the sarcotesta of these cycads but discarding the toxic seed intact. These results suggest cycads are adapted for dispersal fauna capable of swallowing the large, heavy propagules whole, digesting the non-toxic sarcotesta flesh internally, and then voiding the toxic seed intact. Megafauna species such as extant emus or cassowaries, or extinct Pleistocene megafauna such as Genyornis, are plausible candidates for such dispersal. Cycads are an ancient lineage, and the possible antiquity of their megafaunal seed dispersal adaptations are discussed. PMID:25172315

  4. Relative seed and fruit toxicity of the Australian cycads Macrozamia miquelii and Cycas ophiolitica: further evidence for a megafaunal seed dispersal syndrome in cycads, and its possible antiquity.

    PubMed

    Hall, J A; Walter, G H

    2014-08-01

    An apparent contradiction in the ecology of cycad plants is that their seeds are known to be highly poisonous, and yet they seem well adapted for seed dispersal by animals, as shown by their visually conspicuous seed cones and large seeds presented within a brightly colored fleshy "fruit" of sarcotesta. We tested if this sarcotesta could function as a reward for cycad seed dispersal fauna, by establishing if the toxic compound cycasin, known from the seeds, is absent from the sarcotesta. The Australian cycads Macrozamia miquelii and Cycas ophiolitica were tested (N = 10 individuals per species) using gas chromatography / mass spectrometry. Cycasin was detected at 0.34 % (fresh weight) in seed endosperm of M. miquelii and 0.28 % (fresh weight) in seed endosperm of C. ophiolitica. Cycasin was absent from the sarcotesta of the same propagules (none detected in the case of M. miquelii, and trace quantities detected in sarcotesta of only four of the ten C. ophiolitica propagules). This laboratory finding was supported by field observations of native animals eating the sarcotesta of these cycads but discarding the toxic seed intact. These results suggest cycads are adapted for dispersal fauna capable of swallowing the large, heavy propagules whole, digesting the non-toxic sarcotesta flesh internally, and then voiding the toxic seed intact. Megafauna species such as extant emus or cassowaries, or extinct Pleistocene megafauna such as Genyornis, are plausible candidates for such dispersal. Cycads are an ancient lineage, and the possible antiquity of their megafaunal seed dispersal adaptations are discussed.

  5. Ant benefits in a seed dispersal mutualism.

    PubMed

    Gammans, Nicola; Bullock, James M; Schönrogge, Karsten

    2005-11-01

    Myrmecochorous plant seeds have nutrient rich appendages, elaiosomes, which induce some ant species to carry the seeds back to their nest where the elaiosome is consumed and the seed is discarded unharmed. The benefits to plants of dispersal of their seeds in this way have been well documented, but the benefits to the ants from consuming the elaiosomes have rarely been measured and are less clear. Ant benefits from myrmecochory were investigated in a laboratory experiment using the ant Myrmica ruginodis and seeds of Ulex species. To separate the effects of elaiosome consumption on the development of newly produced larvae versus existing larvae, ten 'Queenright' colonies containing a queen were compared to ten 'Queenless' colonies. Six measures of colony fitness over a complete annual cycle were taken: sexual production, larval weight and number, pupal weight and number, and worker survival. Queenless colonies fed with elaiosomes produced 100.0+/-29.3 (mean +/- SE) of larvae compared to non-elaiosome fed colonies which produced 49.6+/-19.0; an increase of 102%. Larval weight increased in both Queenright and Queenless colonies. In colonies fed with elaiosomes, larvae weighed 1.02+/-0.1 mg, but in non-elaiosome fed colonies larvae weighed 0.69+/-0.1 mg; an increase of 48%. The food supplement provided by Ulex elaiosomes was trivial in energetic terms, under the conditions of an ample diet, suggesting that these effects might be due to the presence of essential nutrients. Chemical analysis of Ulex elaiosomes showed the presence of four essential fatty acids and four essential sterols for ants. PMID:16049717

  6. Ethylene synthesis in lettuce seeds: its physiological significance.

    PubMed

    Burdett, A N

    1972-12-01

    The germination and pregermination ethylene production of Grand Rapids lettuce seeds (Lactuca sativa L.) incubated at 20 C after a red light treatment are inhibited if the seeds are first imbibed at 30 C for 36 hours. In this study, low concentrations of ethylene were found to enhance the germination of seeds pretreated at 30 C more than that of untreated controls. In the presence of high concentrations of ethylene, pretreated seeds and controls germinated at a similar rate. These results are consistent with the view that a prolonged imbibition at 30 C inhibits germination at a lower temperature through its effect on the ethylene production of the seeds. As a further test of the hypothesis, estimates were made of the pregermination ethylene content of untreated seeds and pretreated seeds incubated in the presence of sufficient ethylene to make them germinate as rapidly as untreated seeds. The values obtained were 0.65 and 0.74 nanoliter of ethylene per gram (dry weight) of seeds, respectively.

  7. [Nutrition and body weight].

    PubMed

    Gohlke, H

    2002-01-01

    Certain dietary components play a key role for the development of coronary artery disease (CAD). Complex carbohydrates lower the prevalence of CAD. Protein should provide 15% of daily calories. Populations with a high consumption of soy protein have a low coronary event rate and a high life expectancy. Soy protein has a favorable effect on LDL cholesterol, triglycerides and HDL cholesterol. Dietary cholesterol correlates with an increased incidence of CAD. Saturated fats increase cholesterol levels as well as the activity of clotting factor VII and promote progression of CAD. Mono-(MUFA) and poly-unsaturated fatty acids lower LDL-cholesterol to a similar extent. MUFA are contained in rape seed oil, olive oil and pea nut oil, but also in avocados and almonds. Omega-3-fatty acids are in fatty fish like salmon, tuna and herring and improve survival after myocardial infarction. They improve among others endothelial function (adhesion molecules). Eating 1-2 fish meals per week has a preventive effect on CAD and stroke. Dietary fiber decreases the risk for CAD up to 30% and favorably influences carbohydrate metabolism. Antioxidants have a favorable effect in their natural form (fruits and fresh vegetables). The secondary preventive effect of a mediterranean diet after myocardial infarction (probably by a combination of the above effects) has been validated. Body weight correlates with coronary risk, diabetes and use of health care resources. A reduction of body weight is best achieved by calory reduction plus an increase of physical activity. A calory-adjusted diet, low in total fat with a significant proportion of unsaturated fats and omega-3-fatty acids and rich in fiber is of great importance for primary and secondary prevention of cardiovascular diseases. Fruits, vegetables and whole grain products are important components of this diet, which lowers the coronary event rate, increases longevity and is associated with a low rate of malignancies and osteoporosis.

  8. GROWING SEEDS, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT, "GROWING SEEDS," IN WHICH SUCH BASIC SCIENCE SKILLS AND PROCESSES AS MEASUREMENT, OBSERVATION, AND HYPOTHESIS FORMATION ARE INTRODUCED THROUGH STUDENT ACTIVITIES INVOLVING SEEDS, GERMINATION, AND SEEDLING GROWTH. THE MATERIALS WERE DEVELOPED FOR USE IN ELEMENTARY…

  9. A legume biofortification quandary: variability and genetic control of seed coat micronutrient accumulation in common beans

    PubMed Central

    Blair, Matthew W.; Izquierdo, Paulo; Astudillo, Carolina; Grusak, Michael A.

    2013-01-01

    Common beans (Phaseolus vulgaris L.), like many legumes, are rich in iron, zinc, and certain other microelements that are generally found to be in low concentrations in cereals, other seed crops, and root or tubers and therefore are good candidates for biofortification. But a quandary exists in common bean biofortification: namely that the distribution of iron has been found to be variable between the principal parts of seed; namely the cotyledonary tissue, embryo axis and seed coat. The seed coat represents ten or more percent of the seed weight and must be considered specifically as it accumulates much of the anti-nutrients such as tannins that effect mineral bioavailability. Meanwhile the cotyledons accumulate starch and phosphorus in the form of phytates. The goal of this study was to evaluate a population of progeny derived from an advanced backcross of a wild bean and a cultivated Andean bean for seed coat versus cotyledonary minerals to identify variability and predict inheritance of the minerals. We used wild common beans because of their higher seed mineral concentration compared to cultivars and greater proportion of seed coat to total seed weight. Results showed the most important gene for seed coat iron was on linkage group B04 but also identified other QTL for seed coat and cotyledonary iron and zinc on other linkage groups, including B11 which has been important in studies of whole seed. The importance of these results in terms of physiology, candidate genes and plant breeding are discussed. PMID:23908660

  10. The earliest seeds

    USGS Publications Warehouse

    Gillespie, W.H.; Rothwell, G.W.; Scheckler, S.E.

    1981-01-01

    Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

  11. Effects of elevated CO2 concentration on seed production in C3 annual plants.

    PubMed

    Hikosaka, Kouki; Kinugasa, Toshihiko; Oikawa, Shimpei; Onoda, Yusuke; Hirose, Tadaki

    2011-02-01

    The response of seed production to CO(2) concentration ([CO(2)]) is known to vary considerably among C(3) annual species. Here we analyse the interspecific variation in CO(2) responses of seed production per plant with particular attention to nitrogen use. Provided that seed production is limited by nitrogen availability, an increase in seed mass per plant results from increase in seed nitrogen per plant and/or from decrease in seed nitrogen concentration ([N]). Meta-analysis reveals that the increase in seed mass per plant under elevated [CO(2)] is mainly due to increase in seed nitrogen per plant rather than seed [N] dilution. Nitrogen-fixing legumes enhanced nitrogen acquisition more than non-nitrogen-fixers, resulting in a large increase in seed mass per plant. In Poaceae, an increase in seed mass per plant was also caused by a decrease in seed [N]. Greater carbon allocation to albumen (endosperm and/or perisperm) than the embryo may account for [N] reduction in grass seeds. These differences in CO(2) response of seed production among functional groups may affect their fitness, leading to changes in species composition in the future high-[CO(2)] ecosystem.

  12. A crop population perspective on maize seed systems in Mexico

    PubMed Central

    Dyer, George A.; Taylor, J. Edward

    2008-01-01

    Improvement of local germplasm through artificial selection is regarded as the main force behind maize evolution and diversity in Mexico, the crop's center of origin. This perspective neglects the larger social context of maize evolution. Using a theoretical approach and Mexico-wide data, we show that farmer-led evolution of maize is largely driven by a technological diffusion and appropriation process that selectively integrates nonlocal germplasm into local seed stocks. Our approach construes farmer practices as events in the life history of seed to build a demographic model. The model shows how random and systematic differences in management combine to structure maize seed populations into subpopulations that can spread or become extinct, in some cases independently of visible agronomic advantages. The process involves continuous population bottlenecks that can lead to diversity loss. Nonlocal germplasm thus might play a critical role in maintaining diversity in individual localities. Empirical estimates show that introduction of nonlocal seed in Central and Southeastern Mexico is rarer than previously thought; prompt replacement further prevents new seed from spreading. Yet introduced seed perceived as valuable diffuses rapidly, contributing variation in the form of type diversity or through introgression into local seed. Maize seed dynamics and evolution are thus part of a complex social process driven by farmers' desire to appropriate the value in maize farming, not always achieved by preserving or improving local seed stocks. PMID:18184814

  13. Anthropogenic fire drives the evolution of seed traits

    PubMed Central

    Gómez-González, Susana; Torres-Díaz, Cristian; Bustos-Schindler, Carlos; Gianoli, Ernesto

    2011-01-01

    Fire is a major disturbance affecting ecosystems worldwide. Phylogenetic studies have shown that the evolution of seed persistence (fire resistance) is associated with fire frequency or severity. However, the existence of specific seed traits resulting from natural selection mediated by fire remains a key question in plant evolution. We evaluated the role of fire in the evolution of seed traits from a microevolutionary perspective, using as a study system a native forb from the Chilean matorral, where fire is a novel, anthropogenic disturbance. We show that anthropogenic fires are shaping the evolution of seed traits such as pubescence and shape. Among-population variation in seed pubescence, shape, and pericarp thickness was strongly associated with fire frequency, and within a population, fire selected those plants with more pubescent seeds, thicker pericarps, and less rounded seeds. Seed pubescence and shape were shown to be heritable traits. Our findings provide insights into the understanding of the evolution of seed traits in fire-prone environments and demonstrate that human-made fires can be driving evolutionary changes in plant species from ecosystems where fires do not occur naturally. PMID:22065739

  14. Intra-specific variation in genome size in maize: cytological and phenotypic correlates

    PubMed Central

    Realini, María Florencia; Poggio, Lidia; Cámara-Hernández, Julián; González, Graciela Esther

    2016-01-01

    Genome size variation accompanies the diversification and evolution of many plant species. Relationships between DNA amount and phenotypic and cytological characteristics form the basis of most hypotheses that ascribe a biological role to genome size. The goal of the present research was to investigate the intra-specific variation in the DNA content in maize populations from Northeastern Argentina and further explore the relationship between genome size and the phenotypic traits seed weight and length of the vegetative cycle. Moreover, cytological parameters such as the percentage of heterochromatin as well as the number, position and sequence composition of knobs were analysed and their relationships with 2C DNA values were explored. The populations analysed presented significant differences in 2C DNA amount, from 4.62 to 6.29 pg, representing 36.15 % of the inter-populational variation. Moreover, intra-populational genome size variation was found, varying from 1.08 to 1.63-fold. The variation in the percentage of knob heterochromatin as well as in the number, chromosome position and sequence composition of the knobs was detected among and within the populations. Although a positive relationship between genome size and the percentage of heterochromatin was observed, a significant correlation was not found. This confirms that other non-coding repetitive DNA sequences are contributing to the genome size variation. A positive relationship between DNA amount and the seed weight has been reported in a large number of species, this relationship was not found in the populations studied here. The length of the vegetative cycle showed a positive correlation with the percentage of heterochromatin. This result allowed attributing an adaptive effect to heterochromatin since the length of this cycle would be optimized via selection for an appropriate percentage of heterochromatin. PMID:26644343

  15. Magnetic stimulation of marigold seed

    NASA Astrophysics Data System (ADS)

    Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

    2012-10-01

    The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

  16. Weight-ing: the experience of waiting on weight loss.

    PubMed

    Glenn, Nicole M

    2013-03-01

    Perhaps we want to be perfect, strive for health, beauty, and the admiring gaze of others. Maybe we desire the body of our youth, the "healthy" body, the body that has just the right fit. Regardless of the motivation, we might find ourselves striving, wanting, and waiting on weight loss. What is it to wait on weight loss? I explore the meaning of this experience-as-lived using van Manen's guide to phenomenological reflection and writing. Weight has become an increasing focus of contemporary culture, demonstrated, for example, by a growing weight-loss industry and global obesity "epidemic." Weight has become synonymous with health status, and weight loss with "healthier." I examine the weight wait through experiences of the common and uncommon, considering relations to time, body, space, and the other with the aim of evoking a felt, embodied, emotive understanding of the meaning of waiting on weight loss. I also discuss the implications of the findings.

  17. Salinity affects production and salt tolerance of dimorphic seeds of Suaeda salsa.

    PubMed

    Wang, Fengxia; Xu, Yan-Ge; Wang, Shuai; Shi, Weiwei; Liu, Ranran; Feng, Gu; Song, Jie

    2015-10-01

    The effect of salinity on brown seeds/black seeds ratio, seed weight, endogenous hormone concentrations, and germination of brown and black seeds in the euhalophyte Suaeda salsa was investigated. The brown seeds/black seeds ratio, seed weight of brown and black seeds and the content of protein increased at a concentration of 500 mM NaCl compared to low salt conditions (1 mM NaCl). The germination percentage and germination index of brown seeds from plants cultured in 500 mM NaCl were higher than those cultured in 1 mM NaCl, but it was not true for black seeds. The concentrations of IAA (indole-3-acetic acid), ZR (free zeatin riboside) and ABA (abscisic acid) in brown seeds were much greater than those in black seeds, but there were no differences in the level of GAs (gibberellic acid including GA1 and GA3) regardless of the degree of salinity. Salinity during plant culture increased the concentration of GAs, but salinity had no effect on the concentrations of the other three endogenous hormones in brown seeds. Salinity had no effect on the concentration of IAA but increased the concentrations of the other three endogenous hormones in black seeds. Accumulation of endogenous hormones at different concentrations of NaCl during plant growth may be related to seed development and to salt tolerance of brown and black S. salsa seeds. These characteristics may help the species to ensure seedling establishment and population succession in variable saline environments. PMID:26184090

  18. Salinity affects production and salt tolerance of dimorphic seeds of Suaeda salsa.

    PubMed

    Wang, Fengxia; Xu, Yan-Ge; Wang, Shuai; Shi, Weiwei; Liu, Ranran; Feng, Gu; Song, Jie

    2015-10-01

    The effect of salinity on brown seeds/black seeds ratio, seed weight, endogenous hormone concentrations, and germination of brown and black seeds in the euhalophyte Suaeda salsa was investigated. The brown seeds/black seeds ratio, seed weight of brown and black seeds and the content of protein increased at a concentration of 500 mM NaCl compared to low salt conditions (1 mM NaCl). The germination percentage and germination index of brown seeds from plants cultured in 500 mM NaCl were higher than those cultured in 1 mM NaCl, but it was not true for black seeds. The concentrations of IAA (indole-3-acetic acid), ZR (free zeatin riboside) and ABA (abscisic acid) in brown seeds were much greater than those in black seeds, but there were no differences in the level of GAs (gibberellic acid including GA1 and GA3) regardless of the degree of salinity. Salinity during plant culture increased the concentration of GAs, but salinity had no effect on the concentrations of the other three endogenous hormones in brown seeds. Salinity had no effect on the concentration of IAA but increased the concentrations of the other three endogenous hormones in black seeds. Accumulation of endogenous hormones at different concentrations of NaCl during plant growth may be related to seed development and to salt tolerance of brown and black S. salsa seeds. These characteristics may help the species to ensure seedling establishment and population succession in variable saline environments.

  19. The effects of selected pre-treatments on germination of seeds of Oriental hornbeam (Carpinus orientalis).

    PubMed

    Ozel, Halil Bariş

    2016-07-01

    In the present study, the effect of some pre-treatments implemented on seeds of Oriental hornbeam (Carpinus orientalis), which has wide geographical variation along Turkey on germination percentage values were investigated. For this purpose, 13 different pre-treatments were implemented to seeds obtained from 17 different populations. According to the obtained results (except control seeds), pre-treatments leading to lowest germination percentage value (8.1%) in Oriental hornbeam seeds was PT10: Keeping seeds for 90 min in sulfuric acid, while highest germination percentage (86.58%) has been obtained with pre-treatment PT13: Implementation of 40% dose of Baikal EM1 + Biohoumous mixture to the seeds, while lowest germination percentage (40.50%) was observed on seeds collected from P7 (Bartin-Kozcağiz) population, highest germination percentage was observed in seeds obtained from P17 (Artvin-Hopa) population.

  20. The effects of selected pre-treatments on germination of seeds of Oriental hornbeam (Carpinus orientalis).

    PubMed

    Ozel, Halil Bariş

    2016-07-01

    In the present study, the effect of some pre-treatments implemented on seeds of Oriental hornbeam (Carpinus orientalis), which has wide geographical variation along Turkey on germination percentage values were investigated. For this purpose, 13 different pre-treatments were implemented to seeds obtained from 17 different populations. According to the obtained results (except control seeds), pre-treatments leading to lowest germination percentage value (8.1%) in Oriental hornbeam seeds was PT10: Keeping seeds for 90 min in sulfuric acid, while highest germination percentage (86.58%) has been obtained with pre-treatment PT13: Implementation of 40% dose of Baikal EM1 + Biohoumous mixture to the seeds, while lowest germination percentage (40.50%) was observed on seeds collected from P7 (Bartin-Kozcağiz) population, highest germination percentage was observed in seeds obtained from P17 (Artvin-Hopa) population. PMID:27498493

  1. Weight Loss Surgery

    MedlinePlus

    Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you cannot lose weight ... obesity. There are different types of weight loss surgery. They often limit the amount of food you ...

  2. Genetic variability for phenotype, seed production, oil content, and fatty acid composition among 17 Roselle (Hibiscus sabdariffa) accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed oil and fatty acids in plants have human health implications. Oil from roselle (Hibiscus sabdariffa L.) seeds are used in Taiwan as a diuretic, laxative, and tonic. The objectives of this study were to evaluate seeds from 17 roselle accessions for oil and fatty acid variation in a greenhouse. S...

  3. Identification of genes/loci and functional markers for seed oil quality improvement by exploring soybean genetic diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The difference in seed oil composition and content among soybean genotypes can be attributed mostly to variations in transcript sequences and/or transcript accumulation of oil-related genes expressed in seeds. We applied the Illumina HiSeq 2000 system to sequence RNA populations in soybean seeds fro...

  4. Seed Dispersal and Germination Traits of 70 Plant Species Inhabiting the Gurbantunggut Desert in Northwest China

    PubMed Central

    Liu, Huiliang; Zhang, Daoyuan; Yang, Xuejun; Huang, Zhenying; Duan, Shimin; Wang, Xiyong

    2014-01-01

    Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude) of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude), which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory), and anemochorous species were most abundant. Seed mass (F = 3.50, P = 0.01), seed size (F = 8.31, P < 0.01), and seed shape (F = 2.62, P = 0.04) differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight) (P = 0.15), seed size (P = 0.38), or seed shape (variance) (P = 0.95) and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F = 3.64, P = 0.01) and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces. PMID:25485296

  5. Effects of cold plasma treatment on seed germination and seedling growth of soybean.

    PubMed

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-01-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean.

  6. Effects of cold plasma treatment on seed germination and seedling growth of soybean

    NASA Astrophysics Data System (ADS)

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-07-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean.

  7. Effects of cold plasma treatment on seed germination and seedling growth of soybean

    PubMed Central

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-01-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean. PMID:25080862

  8. Seed output and the seed bank in Vallisneria americana (Hydrocharitaceae).

    PubMed

    Lokker, C; Lovett-Doust, L; Lovett-Doust, J

    1997-10-01

    Seed banks and sexual reproduction are known to be significant in colonization and re-establishment of some aquatic macrophyte communities. For highly clonal aquatic macrophytes, however, there is a lack of information on seed production and seed fate as compared with annual sexual species. The seed bank for three populations of Vallisneria americana in the Huron-Erie corridor of the Great Lakes was sampled and quantified in the spring of 1994, and related to seed production in the previous season at these sites. Seed deposition rates during 1994 were also assessed. Sites varied in the proportion of plants flowering and in their tertiary sex ratios, but did not differ in seed numbers produced per unit area. The size of the seed bank was not significantly related to the previous season's seed output, and estimates of seed deposition in the following year tended to be approximately tenfold greater than seed densities found in the seed bank. The stages between seed production and subsequent seed germination are generally very dynamic, with dispersal, mortality, and predation as likely regulating factors. The potential for seedling establishment in V. americana needs to be assessed more fully before the role of seeds in population processes can be determined. PMID:21708549

  9. Fishing for Seeds.

    ERIC Educational Resources Information Center

    Science and Children, 2001

    2001-01-01

    Describes a method to collect seeds that are dispersed from weeds while avoiding some outdoor hazards such as rough terrain or animals. Describes a plan for creating a weed fishing pole and includes a materials list. (SAH)

  10. Seeds in Flight

    ERIC Educational Resources Information Center

    Martin, Willard K.

    1978-01-01

    Discussed are the seed dispersal mechanisms of six different plants: big-leaf maple, pincushion tree, tree of heaven, squirting cucumber, digger pine, and bull thistle. Elaborate color and black-and-white drawings illustrate the text. (MA)

  11. Tomato seeds for LDEF

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Tomato seeds are prepared for their launch aboard the Langley's Long Duration Exposure Facility. Photograph published in Winds of Change, 75th Anniversary NASA publication (page 119), by James Schultz.

  12. Community-Wide Spatial and Temporal Discordances of Seed-Seedling Shadows in a Tropical Rainforest

    PubMed Central

    Rother, Débora Cristina; Pizo, Marco Aurélio; Siqueira, Tadeu; Rodrigues, Ricardo Ribeiro; Jordano, Pedro

    2015-01-01

    Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (2004–2005 and 2007–2009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment. PMID:25856393

  13. Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest.

    PubMed

    Rother, Débora Cristina; Pizo, Marco Aurélio; Siqueira, Tadeu; Rodrigues, Ricardo Ribeiro; Jordano, Pedro

    2015-01-01

    Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (2004-2005 and 2007-2009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment. PMID:25856393

  14. Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest.

    PubMed

    Rother, Débora Cristina; Pizo, Marco Aurélio; Siqueira, Tadeu; Rodrigues, Ricardo Ribeiro; Jordano, Pedro

    2015-01-01

    Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (2004-2005 and 2007-2009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment.

  15. Evaluation of antidiarrheal activity of ethanolic extract of Holarrhena antidysenterica seeds in rats

    PubMed Central

    Sharma, Dushyant Kumar; Gupta, Vinod Kumar; Kumar, Surendra; Joshi, Vivek; Mandal, Ravi Shankar Kumar; Prakash, A. G. Bhanu; Singh, Mamta

    2015-01-01

    Aim: The present study was conducted to evaluate the antidiarrheal effect of ethanolic extract of Holarrhena antidysenterica (Family - Apocynaceae) seeds against induced diarrhea in Wistar albino rats. Materials and Methods: The extract was evaluated for castor oil and Escherichia coli induced diarrhea. Extract was given at 100, 200, 400 mg/kg body wt. orally in both protocols. Standard antidiarrheal Loperamide was used at 5 mg/kg body wt. orally in castor oil induced protocol, while standard antibiotic Gentamicin at 8 mg/kg body wt. intraperitoneally was used in E. coli induced diarrhea. In castor oil induced protocol, the percentage inhibition of defecation was calculated for each group, whereas in E. coli induced protocol, change in fecal consistency, and body weight was recorded for each individual rat for 3 days. Results: The severity of castor oil induced diarrhea was reduced significantly (p<0.05) with H. antidysenterica seeds extract at 200 and 400 mg/kg body wt. which showed equivalent effectiveness like that of Loperamide treated groups. Similarly in E. coli induced diarrhea protocol, the mean change in body weight was significantly (p<0.05) higher in positive control, whereas no significant variation was observed in negative control, Gentamicin treated and H. antidysenterica treated group at 200 mg/kg and 400 mg/kg body wt., respectively. Conclusion: The study concluded that ethanolic extract of H. antidysenterica seeds effectively controlled diarrhea and decreased the severity of clinical signs of castor oil and E. coli induced diarrhea in Wistar rats. PMID:27047049

  16. Seed dispersal in fens

    USGS Publications Warehouse

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  17. Seed reserve composition in 19 tree species of a tropical deciduous forest in Mexico and its relationship to seed germination and seedling growth

    PubMed Central

    Soriano, Diana; Orozco-Segovia, Alma; Márquez-Guzmán, Judith; Kitajima, Kaoru; Gamboa-de Buen, Alicia; Huante, Pilar

    2011-01-01

    Background and Aims The size and composition of seed reserves may reflect the ecological strategy and evolutionary history of a species and also temporal variation in resource availability. The seed mass and composition of seed reserves of 19 co-existing tree species were studied, and we examined how they varied among species in relation to germination and seedling growth rates, as well as between two years with contrasting precipitation (652 and 384 mm). Methods Seeds were collected from a tropical deciduous forest in the northwest of Mexico (Chamela Biological Station). The seed dry mass, with and without the seed coat, and the concentrations of lipids, nitrogen and non-structural carbohydrates for the seed minus seed coat were determined. The anatomical localization of these reserves was examined using histochemical analysis. The germination capacity, rate and lag time were determined. The correlations among these variables, and their relationship to previously reported seedling relative growth rates, were evaluated with and without phylogenetic consideration. Key Results There were interannual differences in seed mass and reserve composition. Seed was significantly heavier after the drier year in five species. Nitrogen concentration was positively correlated with seed coat fraction, and was significantly higher after the drier year in 12 species. The rate and lag time of germination were negatively correlated with each other. These trait correlations were also supported for phylogenetic independent contrasts. Principal component analysis supported these correlations, and indicated a negative association of seedling relative growth rate with seed size, and a positive association of germination rate with nitrogen and lipid concentrations. Conclusions Nitrogen concentration tended to be higher after the drier year and, while interannual variations in seed size and reserve composition were not sufficient to affect interspecific correlations among seed and seedling

  18. Weighted triangulation adjustment

    USGS Publications Warehouse

    Anderson, Walter L.

    1969-01-01

    The variation of coordinates method is employed to perform a weighted least squares adjustment of horizontal survey networks. Geodetic coordinates are required for each fixed and adjustable station. A preliminary inverse geodetic position computation is made for each observed line. Weights associated with each observed equation for direction, azimuth, and distance are applied in the formation of the normal equations in-the least squares adjustment. The number of normal equations that may be solved is twice the number of new stations and less than 150. When the normal equations are solved, shifts are produced at adjustable stations. Previously computed correction factors are applied to the shifts and a most probable geodetic position is found for each adjustable station. Pinal azimuths and distances are computed. These may be written onto magnetic tape for subsequent computation of state plane or grid coordinates. Input consists of punch cards containing project identification, program options, and position and observation information. Results listed include preliminary and final positions, residuals, observation equations, solution of the normal equations showing magnitudes of shifts, and a plot of each adjusted and fixed station. During processing, data sets containing irrecoverable errors are rejected and the type of error is listed. The computer resumes processing of additional data sets.. Other conditions cause warning-errors to be issued, and processing continues with the current data set.

  19. Effects of dietary Crotalaria pallida seeds on the health and performance of laying hens and evaluation of residues in eggs.

    PubMed

    Diaz, Gonzalo J; Almeida, Leidy X; Gardner, Dale R

    2014-10-01

    The effect of three dietary concentrations of Crotalaria pallida (C. pallida) seeds (0, 1, 2, and 3% w/w) of their normal diet were investigated in commercial laying hens during a 35 day feeding trial. All concentrations of C. pallida decreased body weight and feed intake (P < 0.05). Egg mass production and average egg weight were decreased by feeding of ≥ 2% C. pallida seeds (P < 0.05). All concentrations of C. pallida increased relative lung weight and serum activity of ALT, AST and LDH (P < 0.05); 3% C. pallida seeds decreased liver weight (P < 0.05). Analysis of the C. pallida seeds for dehydropyrrolizidine alkaloid content detected usaramine and its N-oxide at a total alkaloid concentration of 0.18% (dry weight). Usaramine was also detected in the eggs of all hens fed C. pallida seeds.

  20. A lipid transfer protein, OsLTPL36, is essential for seed development and seed quality in rice.

    PubMed

    Wang, Xin; Zhou, Wei; Lu, Zhanhua; Ouyang, Yidan; O, Chol Su; Yao, Jialing

    2015-10-01

    Storage lipid is a vital component for maintaining structure of seed storage substances and valuable for rice quality and food texture. However, the knowledge of lipid transporting related genes and their function in seed development have not been well elucidated yet. In this study, we identified OsLTPL36, a homolog of putative lipid transport protein, and showed specific expression in rice developing seed. Transcriptional profiling and in situ hybridization analysis confirmed that OsLTPL36 was exclusively expressed in developing seed coat and endosperm aleurone cells. Down-regulated expression of OsLTPL36 led to decreased seed setting rate and 1000-grain weight in transgenic plants. Further studies showed that suppressed expression of OsLTPL36 caused chalky endosperm and resulted in reduced fat acid content in RNAi lines as compared with wild type (WT). Histological analysis showed that the embryo development was delayed after down regulation of OsLTPL36. Moreover, impeded seed germination and puny seedling were also observed in the OsLTPL36 RNAi lines. The data demonstrated that OsLTPL36, a lipid transporter, was critical important not only for seed quality but also for seed development and germination in rice.

  1. A seed coat-specific promoter for canola.

    PubMed

    El-Mezawy, Aliaa; Wu, Limin; Shah, Saleh

    2009-12-01

    The canola industry generates more than $11 billion of yearly income to the Canadian economy. One problem of meal quality is the dark polyphenolic pigments that accumulate in the seed coat. Seed coat-specific promoters are a pre-requisite to regulate the genes involved in seed coat development and metabolism. The beta-glucuronidase (GUS) reporter gene was used to test an Arabidopsis promoter in developing and mature seeds of canola (Brassica napus). The promoter tested is the regulatory region of the laccase gene (AtLAC15) from Arabidopsis thaliana. The AtLAC15 promoter::GUS construct was inserted into canola double haploid line DH12075 using Agrobacterium-mediated transformation. Southern blot analysis using a 536 bp GUS probe showed variation among the transformed plants in the T-DNA copy numbers and the position of the insertion in their genomes. Histochemical assay of the GUS enzyme in different tissues (roots, leaves, stem, pollen grains, flowers, siliques, embryos and seed coats) showed ascending GUS activity only in the seed coat from 10 days after pollination (DAP) to the fully mature stage (35 DAP). GUS stain was observed in the mucilage cell layer, in the outer integument layer of the seed coat but not in the inner integument. The AtLAC15 promoter exhibited a specificity and expression level that is useful as a seed coat-specific promoter for canola. PMID:19690805

  2. Seed size, fecundity and postfire regeneration strategy are interdependent in Hakea.

    PubMed

    El-ahmir, Sh-hoob Mohamed; Lim, Sim Lin; Lamont, Byron B; He, Tianhua

    2015-01-01

    Seed size is a key functional trait that affects plant fitness at the seedling stage and may vary greatly with species fruit size, growth form and fecundity. Using structural equation modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network between seed size and fecundity, postfire regeneration strategy, fruit size, plant height and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea, with a wide spectrum of seed sizes (2-500 mg). Seed size is negatively correlated with fecundity, while fire-killed species (nonsprouters) produce more seeds than resprouters though they are of similar size. Seed size is unrelated to plant height and level of serotiny while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a causal relationship between seed size, fecundity and postfire regeneration strategy in Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have had most control over seed size variation among Hakea species. PMID:26035821

  3. Seed Size, Fecundity and Postfire Regeneration Strategy Are Interdependent in Hakea

    PubMed Central

    El-ahmir, Sh-hoob Mohamed; Lim, Sim Lin; Lamont, Byron B.; He, Tianhua

    2015-01-01

    Seed size is a key functional trait that affects plant fitness at the seedling stage and may vary greatly with species fruit size, growth form and fecundity. Using structural equation modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network between seed size and fecundity, postfire regeneration strategy, fruit size, plant height and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea, with a wide spectrum of seed sizes (2–500 mg). Seed size is negatively correlated with fecundity, while fire-killed species (nonsprouters) produce more seeds than resprouters though they are of similar size. Seed size is unrelated to plant height and level of serotiny while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a causal relationship between seed size, fecundity and postfire regeneration strategy in Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have had most control over seed size variation among Hakea species. PMID:26035821

  4. Informed Test Component Weighting.

    ERIC Educational Resources Information Center

    Rudner, Lawrence M.

    2001-01-01

    Identifies and evaluates alternative methods for weighting tests. Presents formulas for composite reliability and validity as a function of component weights and suggests a rational process that identifies and considers trade-offs in determining weights. Discusses drawbacks to implicit weighting and explicit weighting and the difficulty of…

  5. Seeds in space experiment results

    NASA Technical Reports Server (NTRS)

    Alston, Jim A.

    1991-01-01

    Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed on the space exposed experiment developed for students (SEEDS) tray in sealed canister number six and in two small vented canisters. The tray was in the F-2 position. The seeds were germinated and the germination rates and development of the resulting plants compared to the control seed that stayed in Park Seed's seed storage facility. The initial results are presented. There was a better survival rate in the sealed canister in space than in the storage facility at Park Seed. At least some of the seeds in each of the vented canisters survived the exposure to vacuum for almost six years. The number of observed apparent mutations was very low.

  6. Seed Transmission of Pseudoperonospora cubensis

    PubMed Central

    Cohen, Yigal; Rubin, Avia E.; Galperin, Mariana; Ploch, Sebastian; Runge, Fabian; Thines, Marco

    2014-01-01

    Pseudoperonospora cubensis, an obligate biotrophic oomycete causing devastating foliar disease in species of the Cucurbitaceae family, was never reported in seeds or transmitted by seeds. We now show that P. cubensis occurs in fruits and seeds of downy mildew-infected plants but not in fruits or seeds of healthy plants. About 6.7% of the fruits collected during 2012–2014 have developed downy mildew when homogenized and inoculated onto detached leaves and 0.9% of the seeds collected developed downy mildew when grown to the seedling stage. This is the first report showing that P. cubensis has become seed-transmitted in cucurbits. Species-specific PCR assays showed that P. cubensis occurs in ovaries, fruit seed cavity and seed embryos of cucurbits. We propose that international trade of fruits or seeds of cucurbits might be associated with the recent global change in the population structure of P. cubensis. PMID:25329308

  7. Automated seed manipulation and planting

    NASA Technical Reports Server (NTRS)

    Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

    1988-01-01

    The Mechanical Division fabricated three seed separators utilizing pressure gradients to move and separate wheat seeds. These separators are called minnow buckets and use air, water, or a combination of both to generate the pressure gradient. Electrostatic fields were employed in the seed separator constructed by the Electrical Division. This separator operates by forcing a temporary electric dipole on the wheat seeds and using charged electrodes to attract and move the seeds. Seed delivery to the hydroponic growth tray is accomplished by the seed cassette. The cassette is compatible with all the seed separators, and it consists of a plastic tube threaded with millipore filter paper. During planting operations, the seeds are placed in an empty cassette. The loaded cassette is then placed in the growth tray and nutrient solution provided. The solution wets the filter paper and capillary action draws the nutrients up to feed the seeds. These seeding systems were tested and showed encouraging results. Seeds were effectively separated and the cassette can support the growth of wheat plants. Problems remaining to be investigated include improving the success of delivering the seeds to the cassette and providing adequate spacing between seeds for the electric separator.

  8. Common vetch (Vicia sativa L.) germplasm: correlations of crude protein and mineral content to seed traits.

    PubMed

    Uzun, Aysen; Gücer, Seref; Acikgoz, Esvet

    2011-09-01

    In order to increase knowledge of seed nutritive value and to demonstrate its relationship in common vetch (Vicia sativa L.) germplasm, 388 common vetch accessions were grown under field conditions in 2008-2009 growing season in Bursa province of Turkey. Seeds were analyzed for seed minerals (Ca, Cu, Mg, Mn, P, S, Zn and K) and crude protein (CP) content. The accessions were grouped according to testa and cotyledon color and seed size, and the results were evaluated by analysis of variance to determine relationships between minerals and CP content, testa and cotyledon colors, and seed weight. In general, there was no significant difference between testa colors or cotyledon colors in minerals and CP content. However, seed weight was closely associated with minerals and CP contents in this study. Analysis of variance and correlation analysis showed that seed weight was closely associated with some minerals and CP content. The small seeds had significantly higher Ca, Cu, Mg, Mn, S, Zn and CP contents than medium and large seeds.

  9. Volatile fingerprints of seeds of four species indicate the involvement of alcoholic fermentation, lipid peroxidation, and Maillard reactions in seed deterioration during ageing and desiccation stress

    PubMed Central

    Colville, Louise

    2012-01-01

    The volatile compounds released by orthodox (desiccation-tolerant) seeds during ageing can be analysed using gas chromatography–mass spectrometry (GC-MS). Comparison of three legume species (Pisum sativum, Lathyrus pratensis, and Cytisus scoparius) during artificial ageing at 60% relative humidity and 50 °C revealed variation in the seed volatile fingerprint between species, although in all species the overall volatile concentration increased with storage period, and changes could be detected prior to the onset of viability loss. The volatile compounds are proposed to derive from three main sources: alcoholic fermentation, lipid peroxidation, and Maillard reactions. Lipid peroxidation was confirmed in P. sativum seeds through analysis of malondialdehyde and 4-hydroxynonenal. Volatile production by ageing orthodox seeds was compared with that of recalcitrant (desiccation-sensitive) seeds of Quercus robur during desiccation. Many of the volatiles were common to both ageing orthodox seeds and desiccating recalcitrant seeds, with alcoholic fermentation forming the major source of volatiles. Finally, comparison was made between two methods of analysis; the first used a Tenax adsorbent to trap volatiles, whilst the second used solid phase microextraction to extract volatiles from the headspace of vials containing powdered seeds. Solid phase microextraction was found to be more sensitive, detecting a far greater number of compounds. Seed volatile analysis provides a non-invasive means of characterizing the processes involved in seed deterioration, and potentially identifying volatile marker compounds for the diagnosis of seed viability loss. PMID:23175670

  10. A Proteomics-Based Platform for Systems Biology Analysis of Soybean Seed Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A system based on fresh weight and color was used to define eight stages of soybean (Glycine max (L.) Merrill, cv. Jack) seed development. Storage protein, oil, and starch were quantified from each stage, and used along with the morphological characteristics to establish a first-stage model of seed...

  11. Magnetic-seeding filtration

    SciTech Connect

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  12. Assessing Your Weight

    MedlinePlus

    ... Measure and Interpret Weight Status Adult Body Mass Index or BMI Body Mass Index (BMI) is a person's weight in kilograms divided ... finding your height and weight in this BMI Index Chart 1 . If your BMI is less than ...

  13. Evidence for maternal control of seed size in maize from phenotypic and transcriptional analysis

    PubMed Central

    Zhang, Xia; Hirsch, Candice N.; Sekhon, Rajandeep S.; de Leon, Natalia; Kaeppler, Shawn M.

    2016-01-01

    Seed size is an important component of grain yield and a key determinant trait for crop domestication. The Krug Yellow Dent long-term selection experiment for large and small seed provides a valuable resource to dissect genetic and phenotypic changes affecting seed size within a common genetic background. In this study, inbred lines derived from Krug Large Seed (KLS) and Krug Small Seed (KSS) populations and reciprocal F1 crosses were used to investigate developmental and molecular mechanisms governing seed size. Seed morphological characteristics showed striking differences between KLS and KSS inbred lines, and the reciprocal cross experiment revealed a strong maternal influence on both seed weight and seed size. Quantification of endosperm area, starchy endosperm cell size, and kernel dry mass accumulation indicated a positive correlation between seed size, endosperm cell number, and grain filling rate, and patterns of grain filling in reciprocal crosses mirrored that of the maternal parent. Consistent with the maternal contribution to seed weight, transcriptome profiling of reciprocal F1 hybrids showed substantial similarities to the maternal parent. A set of differentially expressed genes between KLS and KSS inbreds were found, which fell into a broad number of functional categories including DNA methylation, nucleosome assembly, and heat stress response. In addition, gene co-expression network analysis of parental inbreds and reciprocal F1 hybrids identified co-expression modules enriched in ovule development and DNA methylation, implicating these two processes in seed size determination. These results expand our understanding of seed size regulation and help to uncover the developmental and molecular basis underlying maternal control of seed size in maize. PMID:26826570

  14. Measurement of single soybean seed attributes by near infrared technologies. A comparative study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four near infrared spectrophotometers, and their associated spectral collection methods, were tested and compared for measuring three soybean single seed attributes: weight (g), protein (%), and oil (%). Using partial least squares (PLS) and 4 preprocessing methods, the attribute which was significa...

  15. Effects of frugivorous birds on seed retention time and germination in Xishuangbanna, southwest China.

    PubMed

    Shi, Ting-Ting; Wang, Bo; Quan, Rui-Chang

    2015-07-18

    The dispersal of many plants depends on transportation by birds as seed dispersers. The birds play an important role in long distance seed dispersal and may also affect seed germination. However, for plants who have many bird dispersers, the influence of dominant and non-dominant dispersers on retention time (dispersal distance) and germination remains poorly understood. In this study, we performed experiments with captive frugivorous birds and fruiting plant species to study the effects of dominant and non-dominant dispersers on seed retention time (SRT) and germination (seed germination percentage and germination speed). Our study showed a great interspecific variation in the effects of frugivorous birds on both SRT and germination. Some birds enhance the germination of a given plant species, but others do not. Generally, the dominant visitors improved the seed germination and performed longer seed retention time.

  16. Effects of frugivorous birds on seed retention time and germination in Xishuangbanna, southwest China

    PubMed Central

    SHI, Ting-Ting; WANG, Bo; QUAN, Rui-Chang

    2015-01-01

    The dispersal of many plants depends on transportation by birds as seed dispersers. The birds play an important role in long distance seed dispersal and may also affect seed germination. However, for plants who have many bird dispersers, the influence of dominant and non-dominant dispersers on retention time (dispersal distance) and germination remains poorly understood. In this study, we performed experiments with captive frugivorous birds and fruiting plant species to study the effects of dominant and non-dominant dispersers on seed retention time (SRT) and germination (seed germination percentage and germination speed). Our study showed a great interspecific variation in the effects of frugivorous birds on both SRT and germination. Some birds enhance the germination of a given plant species, but others do not. Generally, the dominant visitors improved the seed germination and performed longer seed retention time. PMID:26228475

  17. Genetic architecture and mechanism of seed number per pod in rapeseed: elucidated through linkage and near-isogenic line analysis

    PubMed Central

    Yang, Yuhua; Shi, Jiaqin; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2016-01-01

    Seed number per pod (SNPP) is one of the major yield components and breeding targets in rapeseed that shows great variation and is invaluable for genetic improvement. To elucidate the genetic architecture and uncover the mechanism of SNPP, we identified five quantitative trait loci (QTLs) using the BnaZNRIL population, which were integrated with those of previous studies by physical map to demonstrate a complex and relatively complete genetic architecture of SNPP. A major QTL, qSN.A6, was successfully fine-mapped from 1910 to 267 kb using near-isogenic line (NIL). In addition, qSN.A6 exhibited an antagonistic pleiotropy on seed weight (SW), which is caused by a physiological interaction in which SNPP acts “upstream” of SW. Because the negative effect of qSN.A6 on SW cannot fully counteract its positive effect on SNPP, it also enhanced the final yield (17.4%), indicating its great potential for utilization in breeding. The following genetic and cytological experiments further confirmed that the different rate of ovule abortion was responsible for the ~5 seed difference between Zhongshuang11 and NIL-qSN.A6. This systematic approach to dissecting the comprehensive genetic architecture of SNPP and characterizing the underlying mechanism has advanced the understanding of SNPP and will facilitate the development of high-yield cultivars. PMID:27067010

  18. Enhancement of seed vigour following insecticide and phenolic elicitor treatment.

    PubMed

    Horii, A; McCue, P; Shetty, K

    2007-02-01

    Thiamethoxam (CGA 293'343) is a novel broad-spectrum neonicotinoid insecticide. It is commercially used as a seed treatment under the trademark Cruiser (CRZ). Although many reports detail its insecticidal, plant-protecting properties, there are minimal reports concerning the effect on seed germination activities which can be key control points of seedling vigour. In this report, we investigated the effect of CRZ, fish protein hydrolysates (FPH; a known elicitor of pentose-phosphate pathway) and the combination of CRZ and FPH (CF) on seed vigour of pea, soybean and corn. Seed vigour was investigated by estimating germination percentage, shoot height, shoot weight, total soluble phenolic content, antioxidant content, G6PDH (glucose-6-phosphate dehydrogenase) activity, and GPX (guaiacol peroxidase) activity. Addition of FPH to CRZ (CF) seemed to have a slightly positive effect on seed vigour, especially, CF and FPH treatment for corn and FPH treatment for pea, suggesting that pre-sowing treatments may cause positive/negative effects on seed vigour, depending on the concentration of treatments. Further research will be needed to determine their effects and the optimal concentration for seed priming.

  19. Construction of weighted upwind compact scheme

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjie

    Enormous endeavor has been devoted in spatial high order high resolution schemes in more than twenty five years previously, like total variation diminishing (TVD), essentially non-oscillatory scheme, weighted essentially non-oscillatory scheme for finite difference, and Discontinuous Galerkin methods for finite element and the finite volume. In this dissertation, a high order finite difference Weighted Upwind Compact Scheme has been constructed by dissipation and dispersion analysis. Secondly, a new method to construct global weights has been tested. Thirdly, a methodology to compromise dissipation and dispersion in constructing Weighted Upwind Compact Scheme has been derived. Finally, several numerical test cases have been shown.

  20. Magnetic-seeding filtration

    SciTech Connect

    Depaoli, D.

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  1. Seed Dormancy and Germination

    PubMed Central

    Bentsink, Leónie; Koornneef, Maarten

    2008-01-01

    Seed dormancy allows seeds to overcome periods that are unfavourable for seedling established and is therefore important for plant ecology and agriculture. Several processes are known to be involved in the induction of dormancy and in the switch from the dormant to the germinating state. The role of plant hormones, the different tissues and genes involved, including newly identified genes in dormancy and germination are described in this chapter, as well as the use transcriptome, proteome and metabolome analyses to study these mechanistically not well understood processes. PMID:22303244

  2. Genome-Wide Analysis of Branched-Chain Amino Acid Levels in Arabidopsis Seeds[W

    PubMed Central

    Angelovici, Ruthie; Lipka, Alexander E.; Deason, Nicholas; Gonzalez-Jorge, Sabrina; Lin, Haining; Cepela, Jason; Buell, Robin; Gore, Michael A.; DellaPenna, Dean

    2013-01-01

    Branched-chain amino acids (BCAAs) are three of the nine essential amino acids in human and animal diets and are important for numerous processes in development and growth. However, seed BCAA levels in major crops are insufficient to meet dietary requirements, making genetic improvement for increased and balanced seed BCAAs an important nutritional target. Addressing this issue requires a better understanding of the genetics underlying seed BCAA content and composition. Here, a genome-wide association study and haplotype analysis for seed BCAA traits in Arabidopsis thaliana revealed a strong association with a chromosomal interval containing two BRANCHED-CHAIN AMINO ACID TRANSFERASES, BCAT1 and BCAT2. Linkage analysis, reverse genetic approaches, and molecular complementation analysis demonstrated that allelic variation at BCAT2 is responsible for the natural variation of seed BCAAs in this interval. Complementation analysis of a bcat2 null mutant with two significantly different alleles from accessions Bayreuth-0 and Shahdara is consistent with BCAT2 contributing to natural variation in BCAA levels, glutamate recycling, and free amino acid homeostasis in seeds in an allele-dependent manner. The seed-specific phenotype of bcat2 null alleles, its strong transcription induction during late seed development, and its subcellular localization to the mitochondria are consistent with a unique, catabolic role for BCAT2 in BCAA metabolism in seeds. PMID:24368787

  3. Behavior rather than diet mediates seasonal differences in seed dispersal by Asian elephants.

    PubMed

    Campos-Arceiz, Ahimsa; Larrinaga, Asier R; Weerasinghe, Udayani R; Takatsuki, Seiki; Pastorini, Jennifer; Leimgruber, Peter; Fernando, Prithiviraj; Santamaría, Luis

    2008-10-01

    Digestive physiology and movement patterns of animal dispersers determine deposition patterns for endozoochorously dispersed seeds. We combined data from feeding trials, germination tests, and GPS telemetry of Asian elephants (Elephas maximus) to (1) describe the spatial scale at which Asian elephants disperse seeds; (2) assess whether seasonal differences in diet composition and ranging behavior translate into differences in seed shadows; and (3) evaluate whether scale and seasonal patterns vary between two ecologically distinct areas: Sri Lanka's dry monsoon forests and Myanmar's (Burma) mixed-deciduous forests. The combination of seed retention times (mean 39.5 h, maximum 114 h) and elephant displacement rates (average 1988 m in 116 hours) resulted in 50% of seeds dispersed over 1.2 km (mean 1222-2105 m, maximum 5772 m). Shifts in diet composition did not affect gut retention time and germination of ingested seeds. Elephant displacements were slightly longer, with stronger seasonal variation in Myanmar. As a consequence, seed dispersal curves varied seasonally with longer distances during the dry season in Myanmar but not in Sri Lanka. Seasonal and geographic variation in seed dispersal curves was the result of variation in elephant movement patterns, rather than the effect of diet changes on the fate of ingested seeds.

  4. Fiber and seed loss from seed cotton cleaning machinery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fiber and seed loss from seed cotton cleaning equipment in cotton gins occurs, but the quantity of material lost, factors affecting fiber and seed loss, and the mechanisms that cause material loss are not well understood. Two experiments were conducted to evaluate the effects of different factors on...

  5. Multiple seeds sensitivity using a single seed with threshold.

    PubMed

    Egidi, Lavinia; Manzini, Giovanni

    2015-08-01

    Spaced seeds are a fundamental tool for similarity search in biosequences. The best sensitivity/selectivity trade-offs are obtained using many seeds simultaneously: This is known as the multiple seed approach. Unfortunately, spaced seeds use a large amount of memory and the available RAM is a practical limit to the number of seeds one can use simultaneously. Inspired by some recent results on lossless seeds, we revisit the approach of using a single spaced seed and considering two regions homologous if the seed hits in at least t sufficiently close positions. We show that by choosing the locations of the don't care symbols in the seed using quadratic residues modulo a prime number, we derive single seeds that when used with a threshold t > 1 have competitive sensitivity/selectivity trade-offs, indeed close to the best multiple seeds known in the literature. In addition, the choice of the threshold t can be adjusted to modify sensitivity and selectivity a posteriori, thus enabling a more accurate search in the specific instance at issue. The seeds we propose also exhibit robustness and allow flexibility in usage. PMID:25747382

  6. [Spatial patterns of seed dispersal in Hemiptelea davidii woodland in Keerqin sandy land, China].

    PubMed

    Yang, Yun-Fei; Bai, Yun-Peng; Li, Jian-Dong; Li, Li

    2010-08-01

    In order to reveal the space expansion potential of Hemiptelea davidii woodland in Keerqin sandy land in China, the quantitative spatial characteristics of the seed rain in the understory and at the woodsides, as well as the seed dispersal patterns at the woodsides and of the isolating trees, were analyzed through survey on sequential sampling away from seed source in different directions at the woodsides and isolating trees and random sampling in the understory. The results showed that among three sampling plots, the average density of the seed rain in the understory was the highest (13732.5 +/- 3106.2 seeds x m(-2)). For isolating trees, the seed rain had the highest density (5449.4 +/- 1429.3 seeds x m(-2)) in southeast transect, being significantly higher than that in other directions, and the lowest one (650.2 +/- 631.6 seeds x m(-2)) in the northwest transect, being significantly lower than that in other directions. At the woodsides, the seed rain density was significantly higher in the east and south transects than in the west and north transects. The variation of the seed density was greater, with the variation coefficient being 25.7%-106.3% in different directions in the two plots of isolating trees and woodsides. Same as other anemochorous plants, H. davidii had the characteristics of seed dispersal away from the seed source. In the eight sampling transects, there existed diversity in the patterns of the seed dispersal away from the seed source in per unit area and in accumulated area, including linear, power, exponential, quadratic parabola, and logarithmic functions. It was suggested that the space expansion potential of H. davidii woodland in Keerqin sandy land would be greater in more frequency down wind directions such as the south, southeast, and east than in more frequency upwind directions such as the north, northwest, and west.

  7. Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds.

    PubMed

    Malik, Meghna R; Yang, Wenyu; Patterson, Nii; Tang, Jihong; Wellinghoff, Rachel L; Preuss, Mary L; Burkitt, Claire; Sharma, Nirmala; Ji, Yuanyuan; Jez, Joseph M; Peoples, Oliver P; Jaworski, Jan G; Cahoon, Edgar B; Snell, Kristi D

    2015-06-01

    Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600 000 and 1 500 000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production.

  8. Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds.

    PubMed

    Malik, Meghna R; Yang, Wenyu; Patterson, Nii; Tang, Jihong; Wellinghoff, Rachel L; Preuss, Mary L; Burkitt, Claire; Sharma, Nirmala; Ji, Yuanyuan; Jez, Joseph M; Peoples, Oliver P; Jaworski, Jan G; Cahoon, Edgar B; Snell, Kristi D

    2015-06-01

    Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600 000 and 1 500 000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production. PMID:25418911

  9. Genetic control of soybean seed oil: II. QTL and genes that increase oil concentration without decreasing protein or with increased seed yield.

    PubMed

    Eskandari, Mehrzad; Cober, Elroy R; Rajcan, Istvan

    2013-06-01

    Soybean [Glycine max (L.) Merrill] seed oil is the primary global source of edible oil and a major renewable and sustainable feedstock for biodiesel production. Therefore, increasing the relative oil concentration in soybean is desirable; however, that goal is complex due to the quantitative nature of the oil concentration trait and possible effects on major agronomic traits such as seed yield or protein concentration. The objectives of the present study were to study the relationship between seed oil concentration and important agronomic and seed quality traits, including seed yield, 100-seed weight, protein concentration, plant height, and days to maturity, and to identify oil quantitative trait loci (QTL) that are co-localized with the traits evaluated. A population of 203 F4:6 recombinant inbred lines, derived from a cross between moderately high oil soybean genotypes OAC Wallace and OAC Glencoe, was developed and grown across multiple environments in Ontario, Canada, in 2009 and 2010. Among the 11 QTL associated with seed oil concentration in the population, which were detected using either single-factor ANOVA or multiple QTL mapping methods, the number of QTL that were co-localized with other important traits QTL were six for protein concentration, four for seed yield, two for 100-seed weight, one for days to maturity, and one for plant height. The oil-beneficial allele of the QTL tagged by marker Sat_020 was positively associated with seed protein concentration. The oil favorable alleles of markers Satt001 and GmDGAT2B were positively correlated with seed yield. In addition, significant two-way epistatic interactions, where one of the interacting markers was solely associated with seed oil concentration, were identified for the selected traits in this study. The number of significant epistatic interactions was seven for yield, four for days to maturity, two for 100-seed weight, one for protein concentration, and one for plant height. The identified molecular

  10. Body Weight Relationships in Early Marriage: Weight Relevance, Weight Comparisons, and Weight Talk

    PubMed Central

    Bove, Caron F.; Sobal, Jeffery

    2011-01-01

    This investigation uncovered processes underlying the dynamics of body weight and body image among individuals involved in nascent heterosexual marital relationships in Upstate New York. In-depth, semi-structured qualitative interviews conducted with 34 informants, 20 women and 14 men, just prior to marriage and again one year later were used to explore continuity and change in cognitive, affective, and behavioral factors relating to body weight and body image at the time of marriage, an important transition in the life course. Three major conceptual themes operated in the process of developing and enacting informants’ body weight relationships with their partner: weight relevance, weight comparisons, and weight talk. Weight relevance encompassed the changing significance of weight during early marriage and included attracting and capturing a mate, relaxing about weight, living healthily, and concentrating on weight. Weight comparisons between partners involved weight relativism, weight competition, weight envy, and weight role models. Weight talk employed pragmatic talk, active and passive reassurance, and complaining and critiquing criticism. Concepts emerging from this investigation may be useful in designing future studies of and approaches to managing body weight in adulthood. PMID:21864601

  11. Adenosine Phosphates in Germinating Radish (Raphanus sativus L.) Seeds 1

    PubMed Central

    Moreland, Donald E.; Hussey, Griscelda G.; Shriner, Carole R.; Farmer, Fred S.

    1974-01-01

    Changes in concentrations of adenosine phosphates (AMP, ADP, and ATP), oxygen utilization, and fresh weights were measured during the first 48 hours after imbibition of water by quiescent radish seeds (Raphanus sativus L.) at 22.5 C. The changes in ATP concentrations, oxygen utilization, and fresh weights followed a triphasic time course, characterized by a rapid initial increase, which extended from 0 to approximately 1.5 hours, a lag phase from 1.5 to 16 hours, and a sharp linear increase from 16 to 48 hours. In unimbibed seeds, the concentrations of ATP, ADP, and AMP were <0.1, 0.9, and 2.2 nmoles/seed, respectively. After imbibition of water by the quiescent seeds, for 1 hour, the ATP concentration had increased to 2.5, and ADP and AMP concentrations had decreased to 0.3 and 0.1 nmole/seed, respectively. These early changes occurred also in seeds maintained under anaerobic conditions (argon), or when treated with either 5 mm fluoroacetate, or 5 mm iodoacetate. The concentrations of ADP and AMP did not change significantly from 1 to 48 hours. The termination of the lag phase at 16 hours correlated with radicle emergence. Cell division in the radicles was initiated at approximately 28 hours. ATP concentrations in seeds maintained under argon or treated with fluoroacetate remained relatively constant from approximately 2 to 48 hours. In contrast, the ATP concentration of iodoacetate-treated seeds decreased curvilinearly from 4 to 48 hours. Oxidative phosphorylation was estimated to have contributed 15, 20, and 65% of the pool ATP at 1.5, 16, and 48 hours, respectively. PMID:16658928

  12. [Desiccation tolerance in seeds of Prosopisferox and Pterogyne nitens (Fabaceae)].

    PubMed

    Morandini, Marcelo Nahuel; Giamminola, Eugenia Mabel; de Viana, Marta Leonor

    2013-03-01

    The high number of endemisms and species diversity together with the accelerated biodiversity loss by deforestation, especially in North Western Argentina, points out the need to work on species conservation combining ex situ and in situ strategies. The aim of this work was to study the desiccation tolerance in seeds of P ferox and P nitens for long term ex situ conservation at the Germplasm Bank of Native Species (BGEN) of the National University of Salta (Argentina). The fruits were collected from ten individuals in P ferox at the National Park Los Cardones and from two sites (Orán and Rivadavia) for P nitens. Desiccation tolerance was assessed following previous established methodologies. The moisture content (MC) of the seeds was determined by keeping them in oven at 103 degreeC and weighting the samples at different intervals till constant weight. Germination essays were carried out with two treatments (control and scarification), with different seed MC (fresh, 10-12%, 3-5%) and in desiccated seeds (3-5% MC) stored six months at -20 degreeC. The MC in P ferox seeds was 14.2% and 10% in P nitens, for both populations studied. Percentage germination in P ferox was higher in the scarification treatments (<82%). The difference between treatments increased with the reduction in MC and the storage for six months at -20 degreeC. Fresh seeds of P nitens do not need scarification treatment, but it is required with the reduction in MC and storage. Mean germination percentage of desiccated seeds stored six months at -20 degreeC was similar in both populations and greater than 82%.We concluded that both species are probably orthodox because seeds tolerated desiccation to 3-5% and storage for six months at -20 degree C. PMID:23894986

  13. Breaking dormancy in freshly matured seeds of Elymus sibiricus, an important forage grass in the Tibetan Plateau.

    PubMed

    Zhang, J Q; Wang, Y R

    2015-09-22

    Elymus sibiricus L. is an important forage grass widely distributed in Asia and is usually a dominant species on Tibetan Plateau alpine grasslands. Here, we used the seed development indices of 1000 seed weight, seed moisture content, and seed viability to compare the seed characteristics at 10, 20, 30, 40, 50, and 60 days after anthesis (DAA) in five populations of E. sibiricus growing in Gannan, China. Additionally, seeds collected at 60 DAA were air-dried for one month, and the primary germination percentage (GP) was determined in the laboratory. Treatment of seeds with 0.2% KNO3, 100 mg/L cytokinin, and 500 mg/L GA3 were tested for their effects on dormancy. A primary GP of 16% was found after 12 d of 15/25°C incubation, with no differences among the five populations. The 1000 seed weight and seed viability steadily increased and moisture content continuously fell with DAA. The optimal harvest time for E. sibiricus in an alpine pasture was 50 DAA. No effect on dormancy was found after treating seeds with 0.2% KNO3 or 100 mg/L cytokinin; however, a low concentration of GA3 induced a prompt and synchronized germination. Freshly matured E. sibiricus seeds were classified to be in non-deep physiologically dormant. Treatment of seeds with GA3 before sowing enhanced the emergence speed and seedling uniformity in E. sibiricus.

  14. Seed morphology and anatomy and its utility in recognizing subfamilies and tribes of Zingiberaceae

    SciTech Connect

    Benedict, John C.; Smith, Selena Y.; Collinson, Margaret E.; Leong-Skornickova, Jana; Specht, Chelsea D.; Marone, Federica; Xiao, Xianghui; Parkinson, Dilworth Y.

    2015-11-01

    PREMISE OF THE STUDY: Recent phylogenetic analyses based on molecular data suggested that the monocot family Zingiberaceae be separated into four subfamilies and four tribes. Robust morphological characters to support these clades are lacking. Seeds were analyzed in a phylogenetic context to test independently the circumscription of clades and to better understand evolution of seed characters within Zingiberaceae. METHODS: Seventy-five species from three of the four subfamilies were analyzed using synchrotron based x-ray tomographic microscopy (SRXTM) and scored for 39 morphoanatomical characters. KEY RESULTS: Zingiberaceae seeds are some of the most structurally complex seeds in angiosperms. No single seed character was found to distinguish each subfamily, but combinations of characters were found to differentiate between the subfamilies. Recognition of the tribes based on seeds was possible for Globbeae, but not for Alpinieae, Riedelieae, or Zingibereae, due to considerable variation. CONCLUSIONS: SRXTM is an excellent, nondestructive tool to capture morphoanatomical variation of seeds and allows for the study of taxa with limited material available. Alpinioideae, Siphonochiloideae, Tamijioideae, and Zingiberoideae are well supported based on both molecular and morphological data, including multiple seed characters. Globbeae are well supported as a distinctive tribe within the Zingiberoideae, but no other tribe could be differentiated using seeds due to considerable homoplasy when compared with currently accepted relationships based on molecular data. Novel seed characters suggest tribal affinities for two currently unplaced Zingiberaceae taxa: Siliquamomum may be related to Riedelieae and Monolophus to Zingibereae, but further work is needed before formal revision of the family.

  15. Thermal Changes of Maize Seed by Laser Irradiation

    NASA Astrophysics Data System (ADS)

    Hernandez-Aguilar, C.; Dominguez-Pacheco, A.; Cruz-Orea, A.

    2015-09-01

    In this research, the thermal evolution in maize seeds ( Zea mays L.) was studied when low-intensity laser irradiation was applied during 60 s. The seeds were irradiated in three different conditions: suspended in air, placed on an aluminum surface, and finally placed on a cardboard; the evolution of the seed temperature was measured by an infrared camera. Photoacoustic spectroscopy and the Rosencwaig and Gersho model were used to determine the optical absorption coefficient (β ) of the seeds. The results indicate that using 650 nm laser light and 27.4 mW, it is possible to produce temperature changes (up to 9.06°C after 1 min) on the seeds. Comparing the mean temperature of the seeds, during and after the incidence of light from a laser, it was found that there were statistically significant differences (P≤ 0.05) from time t1 to time t_{16} (t1 to t_{16}) and t3 to t_{16}, for the laser turned on and off, respectively. The seed condition that had the highest temperature variation, relative to the initial temperature (during the irradiation laser exposure), involved the seeds suspended in air. With regard to the stage of decay of the temperature, it was found that the seed condition that decays more slowly was the seed placed on the cardboard. It was also found that black-dyed maize seeds are optically opaque in the 300 nm to 700 nm range Also, the thermal diffusion length is smaller than the optical penetration length. In the present investigation, it was shown that there is a thermal component associated with the mechanisms of laser biostimulation, which is also a function of the container materials of the seed. In this way, the effects of laser treatment on maize seeds involve at least a temperature effect. It is important to know the temperature changes in the seeds that have been irradiated with a laser beam since they could have substantial practical and theoretical importance.

  16. Identification of transcript polymorphisms for seed quality improvement by exploring soybean genetic diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The difference in seed oil composition and content among soybean genotypes could be mostly attributed to transcript sequence and/or expression variations of oil-related genes that that lead to changes in the functions of the proteins that they encode and/or their accumulation in seeds. We sequenced ...

  17. SEED DETERIORATION INCREASES IN THE PRESENCE OF VOLATILES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeds of culinary importance emit low molecular weight carbonyl compounds that can be detected as volatiles in the surrounding air. Volatile carbonyl molecules are byproducts of cascading peroxidative reactions and can be highly reactive against proteins, lipids and nucleic acids. Carum carvi L. pro...

  18. The effects of Cannabis sativa L. seed (hemp seed) on reproductive and neurobehavioral end points in rats.

    PubMed

    Yousofi, Másume; Saberivand, Adel; Becker, Lora A; Karimi, Isaac

    2011-05-01

    This study determined the effects of maternal dietary intake of hemp seed on reproductive and neurobehavioral end points of Wistar rats. Time-mated rats were fed 100% hemp seed (n  =  15), 50% hemp seed (n  =  15) or basal diet (n  =  15) once a day. The amount of food made available was based on control feed consumption records. All dams remained on their respective diets from premating (14 days) throughout gestation and lactation. After weaning, all pups were given their maternal diet until puberty. Mating and delivery weights of dams in all groups did not show significant changes. Number of pregnancies, number and post-natal survival rate of total rat pups, litter size and milk yield were lower in the group that received 100% hemp seed. Offspring that received 50% hemp seed diet expressed reproductive and neurobehavioral end points from a modified Fox battery earlier than rats on 100% hemp seed or basal diet, except acoustic startle results where no differences appeared. In conclusion, this study shows that hemp seed supplementation does not improve the reproductive and neurobehavioral performances of rats. Pregnant women and nursing mothers should be cautious about the using of Cannabis sativa L. byproducts in their diets.

  19. Physical properties of ebony seed (Pithecellobium flexicaule) and functional properties of whole and defatted ebony seed meal.

    PubMed

    Hernández-Santos, Betsabé; Santiago-Adame, Rubén; Navarro-Cortéz, Ricardo O; Gómez-Aldapa, Carlos A; Castro-Rosas, Javier; Martínez-Sánchez, Cecilia E; Vivar-Vera, María A; Herman-Lara, Erasmo; Rodríguez-Miranda, Jesús

    2015-07-01

    A partial characterization was done of ebony (Pithecellobium flexicaule) seed physical properties, and how defatting affected some functional properties of ebony seed meal. Average seed dimensions were 13.02 mm length, 8.78 mm width and 9.65 mm thickness. Geometric diameter was 10.76 mm, volume was 530 mm(3), surface area was 364.33 mm(2), sphericity was 83.26 % and aspect ratio was 68.24 %. Thousand-seed weight was 0.70 Kg, of which 0.42 Kg (60 %) represented the kernel. Defatted ebony seed meal differed from whole meal in all measured parameters, particularly in its protein (44.72 g/100 g) and carbohydrates (44.12 g/100 g) proportions. The defatted meal had higher water absorption capacity (1.28 g/g sample), water solubility capacity (26.06 %), oil absorption capacity (2.04 g/g sample), emulsifying capacity (53.78 %) and gelling capacity (8 % w/v) than the whole meal. Ebony seed physical properties may prove useful in designing post-harvest processing equipment and in quality control. The high protein content of defatted ebony seed meal suggests its use as a natural alternative ingredient in numerous food industry applications.

  20. Proven Weight Loss Methods

    MedlinePlus

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. It can lower ... at www.hormone.org/Spanish . Proven Weight Loss Methods Fact Sheet www.hormone.org

  1. Canopy position has a profound effect on soybean seed composition.

    PubMed

    Huber, Steven C; Li, Kunzhi; Nelson, Randall; Ulanov, Alexander; DeMuro, Catherine M; Baxter, Ivan

    2016-01-01

    Although soybean seeds appear homogeneous, their composition (protein, oil and mineral concentrations) can vary significantly with the canopy position where they were produced. In studies with 10 cultivars grown over a 3-yr period, we found that seeds produced at the top of the canopy have higher concentrations of protein but less oil and lower concentrations of minerals such as Mg, Fe, and Cu compared to seeds produced at the bottom of the canopy. Among cultivars, mean protein concentration (average of different positions) correlated positively with mean concentrations of S, Zn and Fe, but not other minerals. Therefore, on a whole plant basis, the uptake and allocation of S, Zn and Fe to seeds correlated with the production and allocation of reduced N to seed protein; however, the reduced N and correlated minerals (S, Zn and Fe) showed different patterns of allocation among node positions. For example, while mean concentrations of protein and Fe correlated positively, the two parameters correlated negatively in terms of variation with canopy position. Altering the microenvironment within the soybean canopy by removing neighboring plants at flowering increased protein concentration in particular at lower node positions and thus altered the node-position gradient in protein (and oil) without altering the distribution of Mg, Fe and Cu, suggesting different underlying control mechanisms. Metabolomic analysis of developing seeds at different positions in the canopy suggests that availability of free asparagine may be a positive determinant of storage protein accumulation in seeds and may explain the increased protein accumulation in seeds produced at the top of the canopy. Our results establish node-position variation in seed constituents and provide a new experimental system to identify genes controlling key aspects of seed composition. In addition, our results provide an unexpected and simple approach to link agronomic practices to improve human nutrition and health

  2. Canopy position has a profound effect on soybean seed composition

    PubMed Central

    Ulanov, Alexander; DeMuro, Catherine M.

    2016-01-01

    Although soybean seeds appear homogeneous, their composition (protein, oil and mineral concentrations) can vary significantly with the canopy position where they were produced. In studies with 10 cultivars grown over a 3-yr period, we found that seeds produced at the top of the canopy have higher concentrations of protein but less oil and lower concentrations of minerals such as Mg, Fe, and Cu compared to seeds produced at the bottom of the canopy. Among cultivars, mean protein concentration (average of different positions) correlated positively with mean concentrations of S, Zn and Fe, but not other minerals. Therefore, on a whole plant basis, the uptake and allocation of S, Zn and Fe to seeds correlated with the production and allocation of reduced N to seed protein; however, the reduced N and correlated minerals (S, Zn and Fe) showed different patterns of allocation among node positions. For example, while mean concentrations of protein and Fe correlated positively, the two parameters correlated negatively in terms of variation with canopy position. Altering the microenvironment within the soybean canopy by removing neighboring plants at flowering increased protein concentration in particular at lower node positions and thus altered the node-position gradient in protein (and oil) without altering the distribution of Mg, Fe and Cu, suggesting different underlying control mechanisms. Metabolomic analysis of developing seeds at different positions in the canopy suggests that availability of free asparagine may be a positive determinant of storage protein accumulation in seeds and may explain the increased protein accumulation in seeds produced at the top of the canopy. Our results establish node-position variation in seed constituents and provide a new experimental system to identify genes controlling key aspects of seed composition. In addition, our results provide an unexpected and simple approach to link agronomic practices to improve human nutrition and health

  3. Canopy position has a profound effect on soybean seed composition

    PubMed Central

    Ulanov, Alexander; DeMuro, Catherine M.

    2016-01-01

    Although soybean seeds appear homogeneous, their composition (protein, oil and mineral concentrations) can vary significantly with the canopy position where they were produced. In studies with 10 cultivars grown over a 3-yr period, we found that seeds produced at the top of the canopy have higher concentrations of protein but less oil and lower concentrations of minerals such as Mg, Fe, and Cu compared to seeds produced at the bottom of the canopy. Among cultivars, mean protein concentration (average of different positions) correlated positively with mean concentrations of S, Zn and Fe, but not other minerals. Therefore, on a whole plant basis, the uptake and allocation of S, Zn and Fe to seeds correlated with the production and allocation of reduced N to seed protein; however, the reduced N and correlated minerals (S, Zn and Fe) showed different patterns of allocation among node positions. For example, while mean concentrations of protein and Fe correlated positively, the two parameters correlated negatively in terms of variation with canopy position. Altering the microenvironment within the soybean canopy by removing neighboring plants at flowering increased protein concentration in particular at lower node positions and thus altered the node-position gradient in protein (and oil) without altering the distribution of Mg, Fe and Cu, suggesting different underlying control mechanisms. Metabolomic analysis of developing seeds at different positions in the canopy suggests that availability of free asparagine may be a positive determinant of storage protein accumulation in seeds and may explain the increased protein accumulation in seeds produced at the top of the canopy. Our results establish node-position variation in seed constituents and provide a new experimental system to identify genes controlling key aspects of seed composition. In addition, our results provide an unexpected and simple approach to link agronomic practices to improve human nutrition and health

  4. Canopy position has a profound effect on soybean seed composition.

    PubMed

    Huber, Steven C; Li, Kunzhi; Nelson, Randall; Ulanov, Alexander; DeMuro, Catherine M; Baxter, Ivan

    2016-01-01

    Although soybean seeds appear homogeneous, their composition (protein, oil and mineral concentrations) can vary significantly with the canopy position where they were produced. In studies with 10 cultivars grown over a 3-yr period, we found that seeds produced at the top of the canopy have higher concentrations of protein but less oil and lower concentrations of minerals such as Mg, Fe, and Cu compared to seeds produced at the bottom of the canopy. Among cultivars, mean protein concentration (average of different positions) correlated positively with mean concentrations of S, Zn and Fe, but not other minerals. Therefore, on a whole plant basis, the uptake and allocation of S, Zn and Fe to seeds correlated with the production and allocation of reduced N to seed protein; however, the reduced N and correlated minerals (S, Zn and Fe) showed different patterns of allocation among node positions. For example, while mean concentrations of protein and Fe correlated positively, the two parameters correlated negatively in terms of variation with canopy position. Altering the microenvironment within the soybean canopy by removing neighboring plants at flowering increased protein concentration in particular at lower node positions and thus altered the node-position gradient in protein (and oil) without altering the distribution of Mg, Fe and Cu, suggesting different underlying control mechanisms. Metabolomic analysis of developing seeds at different positions in the canopy suggests that availability of free asparagine may be a positive determinant of storage protein accumulation in seeds and may explain the increased protein accumulation in seeds produced at the top of the canopy. Our results establish node-position variation in seed constituents and provide a new experimental system to identify genes controlling key aspects of seed composition. In addition, our results provide an unexpected and simple approach to link agronomic practices to improve human nutrition and health

  5. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth.

    PubMed

    Ratnikova, Tatsiana A; Podila, Ramakrishna; Rao, Apparao M; Taylor, Alan G

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth.

  6. Identification of a molecular dialogue between developing seeds of Medicago truncatula and seedborne xanthomonads.

    PubMed

    Terrasson, Emmanuel; Darrasse, Armelle; Righetti, Karima; Buitink, Julia; Lalanne, David; Ly Vu, Benoit; Pelletier, Sandra; Bolingue, William; Jacques, Marie-Agnès; Leprince, Olivier

    2015-07-01

    Plant pathogenic bacteria disseminate and survive mainly in association with seeds. This study addresses whether seeds are passive carriers or engage a molecular dialogue with pathogens during their development. We developed two pathosystems using Medicago truncatula with Xanthomonas alfalfae subsp. alfalfae (Xaa), the natural Medicago sp. pathogen and Xanthomonas campestris pv. campestris (Xcc), a Brassicaceae pathogen. Three days after flower inoculation, the transcriptome of Xcc-infected pods showed activation of an innate immune response that was strongly limited in Xcc mutated in the type three secretion system, demonstrating an incompatible interaction of Xcc with the reproductive structures. In contrast, the presence of Xaa did not result in an activation of defence genes. Transcriptome profiling during development of infected seeds exhibited time-dependent and differential responses to Xcc and Xaa. Gene network analysis revealed that the transcriptome of Xcc-infected seeds was mainly affected during seed filling whereas that of Xaa-infected seeds responded during late maturation. The Xcc-infected seed transcriptome exhibited an activation of defence response and a repression of targeted seed maturation pathways. Fifty-one percent of putative ABSCISIC ACID INSENSITIVE3 targets were deregulated by Xcc, including oleosin, cupin, legumin and chlorophyll degradation genes. At maturity, these seeds displayed decreased weight and increased chlorophyll content. In contrast, these traits were not affected by Xaa infection. These findings demonstrate the existence of a complex molecular dialogue between xanthomonads and developing seeds and provides insights into a previously unexplored trade-off between seed development and pathogen defence.

  7. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth

    PubMed Central

    Ratnikova, Tatsiana A.; Podila, Ramakrishna; Rao, Apparao M.; Taylor, Alan G.

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth. PMID:26495423

  8. The SEED Initiative

    ERIC Educational Resources Information Center

    Teich, Carolyn R.

    2011-01-01

    Committed to fulfilling the promise of the green economy, the American Association of Community Colleges (AACC) launched the Sustainability Education and Economic Development (SEED) initiative (www.theseedcenter.org) in October 2010. The project advances sustainability and clean energy workforce development practices at community colleges by…

  9. Magnetic-seeding filtration

    SciTech Connect

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  10. Seeds: A Celebration of Science.

    ERIC Educational Resources Information Center

    Melton, Bob

    The Space Exposed Experiment Developed for Students (SEEDS) Project offered science classes at the 5-12 and college levels the opportunity to conduct experiments involving tomato seeds that had been space-exposed over long periods of time. SEEDS kits were complete packages obtained from the National Aeronautics and Space Administration (NASA) for…

  11. Corridors cause differential seed predation.

    SciTech Connect

    Orrock, John L.; Damschen, Ellen I.

    2005-06-01

    Orrock, John, L., and Ellen I. Damschen. 2005. Corridors cause differential seed predation. Ecol. Apps. 15(3):793-798. Abstract. Corridors that connect disjunct populations are heavily debated in conservation, largely because the effects of corridors have rarely been evaluated by replicated, large-scale studies. Using large-scale experimental landscapes, we found that, in addition to documented positive effects, corridors also have negative impacts on bird-dispersed plants by affecting seed predation, and that overall predation is a function of the seeds primary consumer (rodents or arthropods). Both large-seeded Prunus serotina and small-seeded Rubus allegheniensis experienced greater predation in connected patches. However, P. serotina experienced significantly less seed predation compared to R. allegheniensis in unconnected patches, due to decreased impacts of rodent seed predators on this large-seeded species. Viewed in light of previous evidence that corridors have beneficial impacts by increasing pollination and seed dispersal, this work demonstrates that corridors may have both positive and negative effects for the same plant species at different life stages. Moreover, these effects may differentially affect plant species within the same community: seeds primarily consumed by rodents suffer less predation in unconnected patches. By shifting the impact of rodent and arthropod seed predators, corridors constructed for plant conservation could lead to shifts in the seed bank.

  12. Foliage shedding in deciduous forests lifts up long-distance seed dispersal by wind.

    PubMed

    Nathan, Ran; Katul, Gabriel G

    2005-06-01

    Seed terminal velocity and release height are recognized as key biotic determinants of long-distance dispersal (LDD) of seeds by wind. Yet, potential determinants at the ecosystem level, such as seasonal dynamics in foliage density characterizing many deciduous forests, have received much less attention. We integrated detailed field observations and experiments with a mechanistic wind dispersal model to assess how seasonal variation in foliage density, estimated by leaf-area index (LAI), affects LDD in deciduous forests. We found that the model, previously shown to accurately predict seed dispersal by wind, also reliably describes the effects of LAI variation on wind statistics for a wide range of canopy types. Sparser canopies are characterized by more organized vertical eddy motion that promotes LDD by uplifting seeds to higher elevations where winds are stronger. Yet, sparser canopies are also characterized by reduced mean windspeed aloft. We showed that former effect more than compensates for the latter, i.e., conditions of low LAI are favorable for LDD. This may account for the tendency of many temperate tree species to restrict seed release to either early spring or late fall, when LAI is relatively low. Sensitivity analysis reveals that the typical seasonal variation in LAI can be more important to LDD of seeds by wind than the natural variation in seed terminal velocity. Because our model accurately describes the effects of LAI variation for distinctly different sites, species, and life forms, we suggest that its results reflect a general association between LDD and foliage density dynamics.

  13. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  14. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  15. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  16. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  17. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  18. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  19. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  20. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  1. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  2. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  3. Tree Seed Technology Training Course: Student Outline.

    ERIC Educational Resources Information Center

    Bonner, F. T.; And Others

    This manual is intended primarily to train seed collectors, seed-plant managers, seed analysts, and nursery managers, but can serve as a resource for any training course in forest regeneration. It includes both temperate and tropical tree species of all intended uses and covers the following topics: seed biology, seed collection, seed handling,…

  4. Control of seed development in Arabidopsis thaliana by atmospheric oxygen

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Crispi, M.; Musgrave, M. E.

    1998-01-01

    Seed development is known to be inhibited completely when plants are grown in oxygen concentrations below 5.1 kPa, but apart from reports of decreased seed weight little is known about embryogenesis at subambient oxygen concentrations above this critical level. Arabidopsis thaliana (L.) Heynh. plants were grown full term under continuous light in premixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2 and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen. Seeds were harvested for germination tests and microscopy when siliques had yellowed. Seed germination was depressed in O2 treatments below 16.2 kPa, and seeds from plants grown in 2.5 kPa O2 did not germinate at all. Fewer than 25% of the seeds from plants grown in 5.1 kPa oxygen germinated and most of the seedlings appeared abnormal. Light and scanning electron microscopic observation of non-germinated seeds showed that these embryos had stopped growing at different developmental stages depending upon the prevailing oxygen level. Embryos stopped growing at the heart-shaped to linear cotyledon stage in 5.1 kPa O2, at around the curled cotyledon stage in 10.1 kPa O2, and at the premature stage in 16.2 kPa O2. Globular and heart-shaped embryos were observed in sectioned seeds from plants grown in 2.5 kPa O2. Tissue degeneration caused by cell autolysis and changes in cell structure were observed in cotyledons and radicles. Transmission electron microscopy of mature seeds showed that storage substances, such as protein bodies, were reduced in subambient oxygen treatments. The results demonstrate control of embryo development by oxygen in Arabidopsis.

  5. Ion-pair high-speed countercurrent chromatography in fractionation of a high-molecular weight variation of acyl-oligosaccharide linked betacyanins from purple bracts of Bougainvillea glabra.

    PubMed

    Wybraniec, Sławomir; Jerz, Gerold; Gebers, Nadine; Winterhalter, Peter

    2010-02-15

    The natural pigment composition of purple bracts of Bougainvillea glabra (Nyctaginaceae) consists of a highly complex mixture of betacyanins solely differing by the substitution with a variety of acyl-oligoglycoside units. This study was focused on a two-dimensional chromatography approach, a combination of preparative high-speed countercurrent chromatography (HSCCC) and analytical C18-HPLC with ESI-DAD-MS/MS detection which finally enabled a more detailed view into the pigment profile and elucidated the existence of an overwhelming amount of varying betacyanin structures occurring in Bougainvillea bracts. The detected molecular weights of the pigments reached so far unknown high values and ranged up to maximum values of 1653 and 1683 Da for the largest molecules due to oligosaccharide linkage and multiple acyl substitutions. The preparative IP-HSCCC separation yielded 15 complex fractions containing betacyanins of enhanced polarity as well as structures with highly increased lipophilicity. Betacyanin structures extended by large oligosaccharide chains with bigger number of glycoside units and also carrying a reduced number of hydroxycinnamic acid substitutions were characteristic for polar pigments occurring mainly in the early eluting CCC fractions. IP-HSCCC was proven to be extremely effective for fractionating this complex crude betalain pigment extract into more defined 'polarity-windows'. Structural analysis by analytical LC-ESI-MS/MS in the positive ionization mode detected a total sum of 146 different betacyanin pigments in the CCC fractions of reduced complexity.

  6. Seed priming to alleviate salinity stress in germinating seeds.

    PubMed

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed. PMID:26812088

  7. Seed priming to alleviate salinity stress in germinating seeds.

    PubMed

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed.

  8. High richness and dense seeding enhance grassland restoration establishment but have little effect on drought response.

    PubMed

    Carter, Daniel L; Blair, John M

    2012-06-01

    Restorations commonly utilize seed addition to formerly arable lands where the development of native plant communities is severely dispersal limited. However, variation in seed addition practices may profoundly affect restoration outcomes. Theory and observations predict that species-rich seed mixtures and seeding at high densities should enhance native plant community establishment, minimize exotic species cover, and may promote resistance and resilience to, and recovery from, environmental perturbations. We studied the post-seeding establishment of native plant communities in large grassland restoration plots, which were sown at two densities crossed with two levels of species richness on formerly arable land in Nebraska, USA, and their responses to drought. To evaluate drought resistance, recovery, and resilience of restored plant communities, we erected rainfall manipulation structures and tracked the response of seeded species cover and total plant biomass during experimental drought relative to controls and in the post-drought growing season. High seed richness and high-density seeding treatments resulted in greater richness and cover of native, seeded species per 0.5 m2 compared to low-richness and low-density treatments. Cover differences in response to seed mixture richness were driven by native forbs. Richness and cover of exotic species were lowest in high-richness and high-density treatments. We found little evidence of differential drought resistance, recovery, and resilience among seeding treatments. Increases in exotic species across years were restricted to drought subplots, and were not affected by seeding treatments. Grassland restoration was generally enhanced and exotic cover reduced both by the use of high-richness seed mixtures and high-density seeding. Given the lack of restoration treatment effects on the resistance, recovery, or resilience of seeded species exposed to drought, and the increases in exotic species following drought, other

  9. High richness and dense seeding enhance grassland restoration establishment but have little effect on drought response.

    PubMed

    Carter, Daniel L; Blair, John M

    2012-06-01

    Restorations commonly utilize seed addition to formerly arable lands where the development of native plant communities is severely dispersal limited. However, variation in seed addition practices may profoundly affect restoration outcomes. Theory and observations predict that species-rich seed mixtures and seeding at high densities should enhance native plant community establishment, minimize exotic species cover, and may promote resistance and resilience to, and recovery from, environmental perturbations. We studied the post-seeding establishment of native plant communities in large grassland restoration plots, which were sown at two densities crossed with two levels of species richness on formerly arable land in Nebraska, USA, and their responses to drought. To evaluate drought resistance, recovery, and resilience of restored plant communities, we erected rainfall manipulation structures and tracked the response of seeded species cover and total plant biomass during experimental drought relative to controls and in the post-drought growing season. High seed richness and high-density seeding treatments resulted in greater richness and cover of native, seeded species per 0.5 m2 compared to low-richness and low-density treatments. Cover differences in response to seed mixture richness were driven by native forbs. Richness and cover of exotic species were lowest in high-richness and high-density treatments. We found little evidence of differential drought resistance, recovery, and resilience among seeding treatments. Increases in exotic species across years were restricted to drought subplots, and were not affected by seeding treatments. Grassland restoration was generally enhanced and exotic cover reduced both by the use of high-richness seed mixtures and high-density seeding. Given the lack of restoration treatment effects on the resistance, recovery, or resilience of seeded species exposed to drought, and the increases in exotic species following drought, other

  10. Crop protection by seed coating.

    PubMed

    Ehsanfar, S; Modarres-Sanavy, S A M

    2005-01-01

    Providence of sufficient and healthy food for increasing human population clears the importance of notice to increasing crop production in company with environmental loss reduction. Growth and yield of every plant with sexual reproduction, depends on germination & emergence of sown seeds. Seed is a small alive plant that its biological function is protection and nutrition of embryo. Biological, chemical and physiological characteristics of seed, affect on plant performance & its resistance to undesirable environmental conditions, and even on its total yield. So attention to seed and try to increase its performance is so important. One of the factors that cause reduction in germination percentage and seedling establishment, is seed disease. It's possible to control these diseases by treating the seed before planting it. Coating the seed with pesticides, is one of the ways to gain this goal. Seed coating is a technique in which several material as fertilizers, nutritional elements, moisture attractive or repulsive agents, plant growth regulators, rhizobium inocolum, chemical & pesticide etc, add to seed by adhesive agents and cause to increase seed performance and germination. Seed coating, leads to increase benefits in seed industry, because seeds can use all of their genetic vigor. This technique is used for seeds of many garden plants, valuable crops (such as corn, sunflower, canola, alfalfa,...) and some of the grasses. In this technique that was first used in coating cereal seeds in 1930, a thin and permeable layer of pesticide is stuck on seed surface and prevent damage of seedborn pathogens. This layer is melted or splited after absorption of moisture and suitable temperature by seed, and let the radical to exit the seed. In this approach materials are used accurately with seed, evaporation & leakage of pesticide and also adverse effects of some pesticides on seeds are diminished, and these factors cause to increase the accuracy and performance of pesticide

  11. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...