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1

Survey of halophyte species in China  

Microsoft Academic Search

In this paper we mainly discussed five aspects of halophytes in China. (1) Species of halophytes. (2) Types of halophytes. (3) The vegetation types of halophytes. (4) The halophytes not recorded in the database of Dr Aronson. (5) The economic potential of halophytes. Finally, direction of research and key research areas are suggested.

Zhao Kefu; Fan Hai; I. A. Ungar

2002-01-01

2

The Reference Genome of the Halophytic Plant Eutrema salsugineum  

PubMed Central

Halophytes are plants that can naturally tolerate high concentrations of salt in the soil, and their tolerance to salt stress may occur through various evolutionary and molecular mechanisms. Eutrema salsugineum is a halophytic species in the Brassicaceae that can naturally tolerate multiple types of abiotic stresses that typically limit crop productivity, including extreme salinity and cold. It has been widely used as a laboratorial model for stress biology research in plants. Here, we present the reference genome sequence (241?Mb) of E. salsugineum at 8× coverage sequenced using the traditional Sanger sequencing-based approach with comparison to its close relative Arabidopsis thaliana. The E. salsugineum genome contains 26,531 protein-coding genes and 51.4% of its genome is composed of repetitive sequences that mostly reside in pericentromeric regions. Comparative analyses of the genome structures, protein-coding genes, microRNAs, stress-related pathways, and estimated translation efficiency of proteins between E. salsugineum and A. thaliana suggest that halophyte adaptation to environmental stresses may occur via a global network adjustment of multiple regulatory mechanisms. The E. salsugineum genome provides a resource to identify naturally occurring genetic alterations contributing to the adaptation of halophytic plants to salinity and that might be bioengineered in related crop species.

Yang, Ruolin; Jarvis, David E.; Chen, Hao; Beilstein, Mark A.; Grimwood, Jane; Jenkins, Jerry; Shu, ShengQiang; Prochnik, Simon; Xin, Mingming; Ma, Chuang; Schmutz, Jeremy; Wing, Rod A.; Mitchell-Olds, Thomas; Schumaker, Karen S.; Wang, Xiangfeng

2013-01-01

3

A survey of chemical and nutritional characteristics of halophytes plants used by camels in Southern Tunisia.  

PubMed

The camel (Camelus dromedarius) is well adapted to the utilization of vegetation of low nutritional value in its natural habitat zone, thanks to its aptitude to vary food and to search plants that are rich in water content and that can make up for its nutritional deficits, particularly as concerns mineral elements. Therefore, a survey was carried out to determine camels pasture quality, dietary preference and to characterize the chemical characteristics and nutritional value of different halophytes plants in a region of Southern Tunisia during spring season. Laboratory analysis were conducted on fourteen vegetable species appertained to seven different botanical families: Chenopodiaceae, Graminaceae, Tamaricaceae, Zygophyllaceae, Asteraceae, Frankeniaceae and Plumbaginaceae. Data obtained indicate an high variability of nutritional content of halophytes plants preferred by camels, specially for dry matter, crude protein, fiber fractions, ash and mineral elements. PMID:18500670

Laudadio, Vito; Tufarelli, Vincenzo; Dario, Marco; Hammadi, Mohamed; Seddik, Mabrouk Mouldi; Lacalandra, Giovanni Michele; Dario, Cataldo

2009-02-01

4

Fungal diversity and plant growth promotion of endophytic fungi from six halophytes in Suncheon Bay.  

PubMed

Endophytic fungi were isolated from roots of six halophytes in Suncheon Bay. The endophytic fungi of 35 species isolated from halophytes were identified by internal transcribed spacer (ITS) containing the ITS1, 5.8s, and ITS2 regions. All fungal strains were analyzed to diversity at the genus level. Fungal culture filtrates (FCF) of endophytic fungi were treated to Waito-c rice (WR) seedling for plant growth-promoting verification. It was confirmed that fungal strain Sj-2-2 provided plant growth promotion (PGP) to WR seedling. Then, PGP of Suaeda japonica was confirmed by treating culture filtrate of Sj-2-2. As a result, it was verified that culture filtrate of Sj-2-2 had more advanced PGP than positive control when treated to S. japonica. The secondary metabolites involved in culture filtrate of Sj-2-2 were identified by HPLC and GC-MS SIM analysis. The presence of physiologically bioactive gibberellins (GAs) and other inactive GAs in culture filtrate of Sj-2-2 was detected. The molecular analysis of sequences of Sj-2-2 showed the similarity to Penicillium sp. of 99% homology. The PGP of Sj-2-2 as well as symbiosis between endophytic fungi and halophytes growing naturally in salt marsh was confirmed. Sj-2-2 was identified as a new fungal strain producing GAs by molecular analysis of sequences. Consequently, the Sj-2-2 fungal strain was named as Penicillium sp. Sj-2-2. In this study, the diversity of endophytic fungi isolated from roots of halophytes in salt marsh and the PGP of a new gibberellin-producing fungal strain were confirmed. PMID:23124347

You, Young-Hyun; Yoon, Hyeokjun; Kang, Sang-Mo; Shin, Jae-Ho; Choo, Yeon-Sik; Lee, In-Jung; Lee, Jin-Man; Kim, Jong-Guk

2012-11-01

5

Sulphide tolerance in coastal halophytes  

Microsoft Academic Search

The effect of sulphide on the growth of several species of salt-marsh plants was investigated. Relative growth rates were significantly reduced in two upper-marsh species, Festuca rubra and Atriplex patula, and in the lower-marsh species Puccinellia maritima. However the growth of Salicornia europaea, a species frequently associated with sulphide-containing sediments, was unaffected. In a separate experiment the wide ranging halophyte

D. C. Havill; A. Ingold; J. Pearson

1985-01-01

6

Establishment of cell suspension cultures and plant regeneration in halophytic Leymus chinensis (Trin.)  

Microsoft Academic Search

The establishment of cell suspension culture from the callus of the halophytic Leymus chinensis (Trin.) LcWT07 line and plant regeneration from suspension-derived callus are described in this study for the first time. Solid medium containing Murashige and Shoog (MS) basic salt, 2,4-dichlorophenoxyacetic acid (2,4-D, 2.0 mg l-1), and L-glumatic acid (5.0 mg l-1) induced the highest rate of cell division

Yan-Lin Sun; Soon-Kwan Hong

2010-01-01

7

Use of halophytic plants for recycling NaCl in human liquid waste in a bioregenerative life support system  

NASA Astrophysics Data System (ADS)

The purpose of this work was to develop technology for recycling NaCl containing in human liquid waste as intrasystem matter in a bioregenerative life support system (BLSS). The circulation of Na + and Cl - excreted in urine is achieved by inclusion of halophytes, i.e. plants that naturally inhabit salt-rich soils and accumulate NaCl in their organs. A model of Na + and Cl - recycling in a BLSS was designed, based on the NaCl turnover in the human-urine-nutrient solution-halophytic plant-human cycle. The study consisted of (i) selecting a halophyte suitable for inclusion in a BLSS, and (ii) determining growth conditions supporting maximal Na + and Cl - accumulation in the shoots of the halophyte growing in a nutrient solution simulating mineralized urine. For the selected halophytic plant, Salicornia europaea, growth rate under optimal conditions, biomass production and quantities of Na + and Cl - absorbed were determined. Characteristics of a plant production conveyor consisting of S.europaea at various ages, and allowing continuity of Na + and Cl - turnover, were estimated. It was shown that closure of the NaCl cycle in a BLSS can be attained if the daily ration of fresh Salicornia biomass for a BLSS inhabitant is approximately 360 g.

Balnokin, Yurii; Nikolai, Myasoedov; Larisa, Popova; Alexander, Tikhomirov; Sofya, Ushakova; Christophe, Lasseur; Jean-Bernard, Gros

2010-09-01

8

Stable hydrogen-isotope analysis of methyl chloride emitted from heated halophytic plants  

NASA Astrophysics Data System (ADS)

Stable isotope techniques are increasingly applied to study atmospheric budgets of methyl halides. Here we use compound specific thermal conversion isotope ratio mass spectrometry to measure the stable hydrogen isotope values of methyl chloride (?HCl) released thermally from dried leaves of halophyte plants collected from different geographical locations. We developed an automated purification and pre-concentration unit to enable measurement of ?HCl from samples (100 ml) when mixing ratios were as low as 1 ppmv. Even though this is considerably higher than normal atmospheric mixing ratios this unit enabled measurement of the ?2H values of CH3Cl released during heating of samples at temperatures ranging from 30 to 300 °C. No substantial changes of ?HCl values were observed over this temperature range. However, the ?HCl values of all plants examined were strongly depleted (-178 ± 34‰) relative to the ?2H values of their modelled meteoric water, but differ only by 1-50‰ from those observed for their methoxyl groups. Our results indicate that plant methoxyl groups are an important precursor of the methyl group for CH3Cl thermally emitted from lyophilised and homogenized dry halophyte leaves. Furthermore, the thermal reaction producing CH3Cl did not show a substantial kinetic hydrogen isotope fractionation between CH3Cl and precursor methoxyl groups over the temperature range investigated. Moreover, we found a moderate linear correlation (R2 = 0.37) for the relationship between ?HCl values released from halophytes and the ?2H values of modelled precipitation at their geographical locations. As CH3Cl emissions from terrestrial vegetation, including senescent and dry plants and biomass burning, are considered to provide a substantial fraction of the global emissions our findings are important when establishing a global hydrogen isotope model for atmospheric CH3Cl.

Greule, Markus; Huber, Stefan G.; Keppler, Frank

2012-12-01

9

North American halophytes: Potential use in animal husbandry  

Microsoft Academic Search

\\u000a North America is rich in halophyte plants with over 200 distinct species occurring in coastal and inland regions. They are\\u000a not a single taxonomic group but represent many different taxa and growth forms. Emphasis has shifted from studying halophyte\\u000a ecology and physiology to a serious attempt to utilize them in farming systems. Promising results have been obtained from\\u000a preliminary studies

E. P. Glenn; J. J. Riley; R. S. Swingle; C. U. Mota; M. C. Watson; V. R. Squires

10

Differential Activity of Plasma and Vacuolar Membrane Transporters Contributes to Genotypic Differences in Salinity Tolerance in a Halophyte Species, Chenopodium quinoa.  

PubMed

Halophytes species can be used as a highly convenient model system to reveal key ionic and molecular mechanisms that confer salinity tolerance in plants. Earlier, we reported that quinoa (Chenopodium quinoa Willd.), a facultative C3 halophyte species, can efficiently control the activity of slow (SV) and fast (FV) tonoplast channels to match specific growth conditions by ensuring that most of accumulated Na+ is safely locked in the vacuole (Bonales-Alatorre et al. (2013) Plant Physiology). This work extends these finding by comparing the properties of tonoplast FV and SV channels in two quinoa genotypes contrasting in their salinity tolerance. The work is complemented by studies of the kinetics of net ion fluxes across the plasma membrane of quinoa leaf mesophyll tissue. Our results suggest that multiple mechanisms contribute towards genotypic differences in salinity tolerance in quinoa. These include: (i) a higher rate of Na+ exclusion from leaf mesophyll; (ii) maintenance of low cytosolic Na+ levels; (iii) better K+ retention in the leaf mesophyll; (iv) a high rate of H+ pumping, which increases the ability of mesophyll cells to restore their membrane potential; and (v) the ability to reduce the activity of SV and FV channels under saline conditions. These mechanisms appear to be highly orchestrated, thus enabling the remarkable overall salinity tolerance of quinoa species. PMID:23629664

Bonales-Alatorre, Edgar; Pottosin, Igor; Shabala, Lana; Chen, Zhong-Hua; Zeng, Fanrong; Jacobsen, Sven-Erik; Shabala, Sergey

2013-01-01

11

Sap Concentrations in Halophytes and Some Other Plants  

PubMed Central

Freezing point depression in xylem sap of mangroves was found to range from 0.05 to 0.5°, in desert plants from 0.01 to 0.16°. In crush juices from leaves of Batis and Salicornia, 90% or more of the freezing point depression was made up of sodium and chlorine ions; in mangroves they constituted 50 to 70%, the rest probably being organic solutes. Plants growing in seawater have ?30 to ?60 atmospheres pressure in the xylem sap. As shown earlier, at zero turgor pressure the intracellular freezing point of the parenchyma cells matches closely the negative pressure in the xylem sap. This agrees with the present data, that the fluid which exudes from the xylem by applying gas pressure on the leaves is practically pure water; freezing point is rarely above 0.01 to 0.02°. To perform this ultrafiltration, the plasma membrane is subjected to a hydrostatic pressure gradient which in some cases may exceed 100 atmospheres. Images

Scholander, P. F.; Bradstreet, Edda D.; Hammel, H. T.; Hemmingsen, E. A.

1966-01-01

12

Seasonal effect of three desert halophytes on soil microbial functional diversity  

Microsoft Academic Search

The objective of this study was to evaluate the effect of some plant ecophysiological adaptations on soil microbial functional\\u000a diversity in a Negev Desert ecosystem. Soil samples from the upper 0–10 cm layer were collected at the study site under three\\u000a species of halophyte shrubs, Zygophyllum dumosum, Hammada scoparia, and Reaumuria negevensis. These halophytes represent the most typical cover of

Pinhasi-adiv Yocheved; Steinberger Yosef

2009-01-01

13

Halophytes for the treatment of saline aquaculture effluent  

Microsoft Academic Search

We determined the feasibility of using salt-tolerant plants (halophytes) as biofilters to remove nutrients from saline aquaculture wastewater. Suaeda esteroa, Salicornia bigelovii and Atriplex barclayana (Chenopodiaceae), species with potential as forage and oil seed crops, were grown in sand in draining containers (lysimeters) in a greenhouse experiment. They were irrigated to meet evapotranspiration demand and to produce a 0.3 leaching

J. Jed Brown; Edward P. Glenn; Kevin M. Fitzsimmons; Steven E. Smith

1999-01-01

14

Ion Uptake by Halophytic Plants to Mitigate Saline Stress in Solanum lycopersicon L., and Different Effect of Soil and Water Salinity  

Microsoft Academic Search

Soil and water salinization are affecting an increasing number of countries in the world, especially in arid and semi-arid regions, and cause sensible reductions of agricultural land extension and of crop yields. Consociation with halophytic plants is a promising but not yet widely investigated strategy of salt stress reduc - tion in crops. In this experiment, tomato plants were cultivated

Paolo ZuccaRini

2008-01-01

15

Influence of biological, environmental and technical factors on phenolic content and antioxidant activities of Tunisian halophytes.  

PubMed

Halophyte ability to withstand salt-triggered oxidative stress is governed by multiple biochemical mechanisms that facilitate retention and/or acquisition of water, protect chloroplast functioning, and maintain ion homeostasis. Most essential traits include the synthesis of osmolytes, specific proteins, and antioxidant molecules. This might explain the utilization of some halophytes as traditional medicinal and dietary plants. The present study aimed at assessing the phenolic content and antioxidant activities of some Tunisian halophytes (Cakile maritima, Limoniastrum monopetalum, Mesembryanthemum crystallinum, M. edule, Salsola kali, and Tamarix gallica), depending on biological (species, organ and developmental stage), environmental, and technical (extraction solvent) factors. The total polyphenol contents and antioxidant activities (DPPH and superoxide radicals scavenging activities, and iron chelating and reducing powers) were strongly affected by the above-cited factors. Such variability might be of great importance in terms of valorising these halophytes as a source of naturally secondary metabolites, and the methods for phenolic and antioxidant production. PMID:18940702

Ksouri, Riadh; Megdiche, Wided; Falleh, Hanen; Trabelsi, Nejla; Boulaaba, Mondher; Smaoui, Abderrazak; Abdelly, Chedly

2008-11-01

16

Potential uses of TerraSAR-X for mapping herbaceous halophytes over salt marsh and tidal flats  

NASA Astrophysics Data System (ADS)

This study presents a method and application results of mapping different halophytes over tidal flats and salt marshes using high resolution space-borne X-band synthetic aperture radar (SAR) that has been rarely used for salt marsh mapping. Halophytes in a salt marshes are sensitive to sea-level changes, sedimentation, and anthropogenic modifications. The alteration of the demarcations among halophyte species is an indicator of sea level and environmental changes within a salt marsh. The boundary of an herbaceous halophyte patch is, however, difficult to determine using remotely sensed data because of its sparseness. We examined the ecological status of the halophytes and their distribution changes using TerraSAR-X and optical data. We also determined the optimum season for halophyte mapping. An annual plant, Suaeda japonica (S. japonica), and a typical perennial salt marsh grass, Phragmites australis (P. australis), were selected for halophyte analysis. S. japonica is particularly sensitive to sea level fluctuation. Seasonal variation for the annual plant was more significant (1.47 dB standard deviation) than that for the perennial grass, with a pattern of lower backscattering in winter and a peak in the summer. The border between S. japonica and P. australis was successfully determined based on the distinctive X-band radar backscattering features. Winter is the best season to distinguish between the two different species, while summer is ideal for analyzing the distribution changes of annual plants in salt marshes. For a single polarization, we recommend using HH polarization, because it produces maximum backscattering on tidal flats and salt marshes. Our results show that high resolution SAR, such as TerraSAR-X and Cosmo-SkyMed, is an effective tool for mapping halophyte species in tidal flats and monitoring their seasonal variations.

Lee, Yoon-Kyung; Park, Jeong-Won; Choi, Jong-Kuk; Oh, Yisok; Won, Joong-Sun

2012-12-01

17

Maritime halophyte species from southern Portugal as sources of bioactive molecules.  

PubMed

Extracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC?? = 0.1 mg/mL) and J. acutus (IC?? = 0.4 mg/mL), and the ether extracts of J. acutus (IC?? = 0.2 mg/mL) and A. macrostachyum (IC?? = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC?? = 0.4 mg/mL) and H. portulacoides (IC?? = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC?? = 109 µg/mL) and the hexane extract of P. coronopus (IC?? = 98.0 µg/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells. PMID:24727393

Rodrigues, Maria João; Gangadhar, Katkam N; Vizetto-Duarte, Catarina; Wubshet, Sileshi G; Nyberg, Nils T; Barreira, Luísa; Varela, João; Custódio, Luísa

2014-01-01

18

Maritime Halophyte Species from Southern Portugal as Sources of Bioactive Molecules  

PubMed Central

Extracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC50 = 0.1 mg/mL) and J. acutus (IC50 = 0.4 mg/mL), and the ether extracts of J. acutus (IC50 = 0.2 mg/mL) and A. macrostachyum (IC50 = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2?-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC50 = 0.4 mg/mL) and H. portulacoides (IC50 = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC50 = 109 µg/mL) and the hexane extract of P. coronopus (IC50 = 98.0 µg/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells.

Rodrigues, Maria Joao; Gangadhar, Katkam N.; Vizetto-Duarte, Catarina; Wubshet, Sileshi G.; Nyberg, Nils T.; Barreira, Luisa; Varela, Joao; Custodio, Luisa

2014-01-01

19

[Response characteristics of the field-measured spectrum for the four gerneral types of halophyte and species recognition in the northern slope area of Tianshan Mountain in Xinjiang].  

PubMed

Based on the field-measured Vis-NIR reflectance of four common types of halophyte (Achnatherum splendens(Trin.) Nevski, Sophora alopecuroides L., Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen, Alhagi sparsifolia shap) within given spots in the Northern Slope Area of Tianshan Mountain in Xinjiang, the spectral response characteristics and species recognition of these types of halophyte were analyzed. The results showed that (Alhagi sparsifolia shap) had higher chlorophyll and carotenoid by CARI and SIPI index. (Sophora alopecuroides L. was at a vigorously growing state and had a higher NDVI compared with the other three types of halophyte because of its greater canopy density. But its CARI and SIPI values were lower due to the influence of its flowers. (Sophora alopecuroides L.) and (Camphorosma monspeliaca L. subsp. lessingii(L.)) had stable REPs and BEPs, but REPs and BEPs of (Achnatherum splendens(Trin.)Nevski, Aellen, Alhagi sparsifolia shap) whose spectra red shift and spectra blue shift occurred concurrently obviously changed. There was little difference in spectral curves among the four types of halophyte, so the spectrum mixing phenomenon was severe. (Camphorosma monspeliaca L. subsp. lessingii (L.)Aellen) and (Alhagi sparsifolia shap) could not be separated exactly in a usual R/NIR feature space in remote sensing. Using the stepwise discriminant analysis, five indices were selected to establish the discriminant model, and the model accuracy was discussed using the validated sample group. The total accuracy of the discriminant model was above 92% and (Achnatherum splendens(Trin.)Nevski) and (Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen) could be respectively recognized 100% correctly. PMID:22295790

Zhang, Fang; Xiong, Hei-gang; Nurbay, Abdusalih; Luan, Fu-ming

2011-12-01

20

Biodiversity of halophytic and sabkha ecosystems in Iran  

Microsoft Academic Search

Iran, with a total surface area of 1.6 Mkm2, is a typical country of large sabkhas, littoral and inland salt marshes, and diverse brackish and salty river ecosystems.\\u000a According to our present knowledge and evaluation of new data, a total of 365 species within 151 genera and 44 families of\\u000a Ir anian vascular plants are known to be true halophytes,

Hossein Akhani

21

Isolation and characterization of endophytic plant growth-promoting (PGPB) or stress homeostasis-regulating (PSHB) bacteria associated to the halophyte Prosopis strombulifera  

Microsoft Academic Search

This study was designed to isolate and characterize endophytic bacteria from halophyte Prosopis strombulifera grown under extreme salinity and to evaluate in vitro the bacterial mechanisms related to plant growth promotion or stress\\u000a homeostasis regulation. Isolates obtained from P. strombulifera were compared genotypically by BOX-polymerase chain reaction, grouped according to similarity, and identified by amplification\\u000a and partial sequences of 16S

Verónica Sgroy; Fabricio Cassán; Oscar Masciarelli; María Florencia Del Papa; Antonio Lagares; Virginia Luna

2009-01-01

22

Effects of Two Halophytic Plants (Kochia and Atriplex) on Digestibility, Fermentation and Protein Synthesis by Ruminal Microbes Maintained in Continuous Culture  

PubMed Central

Eight continuous culture fermenters were used in a completely randomized design to evaluate various nutritional values of Kochia (Kochia scoparia) compared with Atriplex (Atriplex dimorphostegia). Dried and pelleted samples (leaves and stems) provided substrate for metabolism by ruminal microbes maintained in a continuous culture fermentation system. Results indicated that there were no differences (p>0.05) in dry matter (DM) and crude protein (CP) digestibility between the two halophytic plants. Atriplex had higher (p<0.05) organic matter (OM) digestibility compared with Kochia. Neutral detergent fiber (aNDF) digestibility of Atriplex (411 g/kg) was higher (p<0.05) than that of Kochia (348 g/kg), however acid detergent fiber (ADF) digestibility was higher (p<0.05) in Kochia compared with Atriplex (406 vs. 234 g/kg). There were no differences (p>0.05) between the two halophytic plants in molar proportion of acetate and propionate, but the concentration of butyrate and valerate in Kochia were about two fold of Atriplex (p<0.05). When Kochia provided substrate to the microbes, protein synthesis was higher (p<0.05) compared with feeding Atriplex (5.96 vs. 4.85 g N/kg of OM truly digested). It was concluded that Kochia scoparia and Atriplex dimorphostegia had similar digestibility of DM and CP. It appears that these halophytic plants may not have enough digestible energy for high producing ruminants.

Riasi, A.; Mesgaran, M. Danesh; Stern, M. D.; Ruiz Moreno, M. J.

2012-01-01

23

Spatial and seasonal variation of salt ions under the influence of halophytes, in a coastal flat in eastern China  

NASA Astrophysics Data System (ADS)

The high salinity of coastal saline field is a key factor limiting the reclamation. Halophytes have been utilized in the reclamation of saline land. The study area is in Yancheng, China. An analysis of the concentrations of Rb, Cs, Sr, and Ba, the ratio of Rb/Cs, and Sr/Ba in soils in autumn shows that the soil of this study area has great homogeneity. Artemisia halodendron, Gossypium hirsutum, and Sesbania cannabina were selected as the reclamation plants in the present study. In order to know the spatial-temporal distribution of soil salinity, the influence of plant-specific vegetation, and the difference of desalination among these halophytes in coastal flat, the authors analyze the soil-layers and seasonal variation in salt ions. Sodium chloride was accumulated in 0-5 cm topsoil with no vegetation during the winter and spring. The effect of desalinization of halophytes is significant. Of the three plant species, Sesbania cannabina has the greatest desalinization. The difference of ions composition of soils covered with various plant species is significant. It can be concluded that halophytes have better amelioration of coastal soil salinity. Special attention should be paid to the selection of plant species and measures to plant and cultivate crops in the reclamation of saline land.

Wu, Yanyou; Liu, Rongcheng; Zhao, Yuguo; Li, Pingping; Liu, Congqiang

2009-06-01

24

Halophytes Energy Feedstocks: Back to Our Roots  

NASA Technical Reports Server (NTRS)

Of the Earth s landmass, approx.43% is arid or semi-arid, and 97% of the Earth s water is seawater. Halophytes are salt-tolerant plants (micro and macro) that can prosper in seawater or brackish waters and are common feedstocks for fuel and food (fuel-food feedstocks) in depressed countries. Two types, broadly classed as coastal and desert, can be found in marshes, coastal planes, inland lakes, and deserts. Major arid or semi-arid halophyte agriculture problems include pumping and draining the required high volumes of irrigation water from sea or ocean sources. Also, not all arid or semi-arid lands are suitable for crops. Benefits of halophyte agriculture include freeing up arable land and freshwater resources, cleansing the environment, decontaminating soils, desalinating brackish waters, and carbon sequestration. Sea and ocean halophyte agriculture problems include storms, transport, and diffuse harvesting. Benefits include available nutrients, ample water, and Sun. Careful attention to details and use of saline agriculture fuel feedstocks are required to prevent anthropogenic disasters. It is shown that the potential for fuel-food feedstock halophyte production is high; based on test plot data, it could supply 421.4 Quad, or 94% of the 2004 world energy consumption and sequester carbon, with major impact on the Triangle of Conflicts.

Hendricks, Robert C.; Bushnell, Dennis M.

2007-01-01

25

An inland and a coastal population of the Mediterranean xero-halophyte species Atriplex halimus L. differ in their ability to accumulate proline and glycinebetaine in response to salinity and water stress.  

PubMed

Soil salinity and drought compromise water uptake and lead to osmotic adjustment in xero-halophyte plant species. These important environmental constraints may also have specific effects on plant physiology. Stress-induced accumulation of osmocompatible solutes was analysed in two Tunisian populations of the Mediteranean shrub Atriplex halimus L.-plants originating from a salt-affected coastal site (Monastir) or from a non-saline semi-arid area (Sbikha)-were exposed to nutrient solution containing either low (40 mM) or high (160 mM) doses of NaCl or 15% polyethylene glycol. The low NaCl dose stimulated plant growth in both populations. Plants from Monastir were more resistant to high salinity and exhibited a greater ability to produce glycinebetaine in response to salt stress. Conversely, plants from Sbikha were more resistant to water stress and displayed a higher rate of proline accumulation. Proline accumulated as early as 24 h after stress imposition and such accumulation was reversible. By contrast, glycinebetaine concentration culminated after 10 d of stress and did not decrease after the stress relief. The highest salt resistance of Monastir plants was not due to a lower rate of Na(+) absorption; plants from this population exhibited a higher stomatal conductance and a prodigal water-use strategy leading to lower water-use efficiency than plants from Sbikha. Exogenous application of proline (1 mM) improved the level of drought resistance in Monastir plants through a decrease in oxidative stress quantified by the malondialdehyde concentration, while the exogenous application of glycinebetaine improved the salinity resistance of Sbikha plants through a positive effect on photosystem II efficiency. PMID:18385490

Ben Hassine, Abir; Ghanem, Michel Edmond; Bouzid, Sadok; Lutts, Stanley

2008-01-01

26

Changes in cellular distribution regulate SKD1 ATPase activity in response to a sudden increase in environmental salinity in halophyte ice plant  

PubMed Central

Halophyte Mesembryanthemum crystallinum L. (ice plant) rapidly responds to sudden increases in salinity in its environment by activating specific salt-tolerant mechanisms. One major strategy is to regulate a series of ion transporters and proton pumps to maintain cellular Na+/K+ homeostasis. Plant SKD1 (suppressor of K+ transport growth defect 1) proteins accumulate in cells actively engaged in the secretory processes, and play a critical role in intracellular protein trafficking. Ice plant SKD1 redistributes from the cytosol to the plasma membrane hours after salt stressed. In combination with present knowledge of this protein, we suggest that stress facilitates SKD1 movement to the plasma membrane where ADP/ATP exchange occurs, and functions in the regulation of membrane components such as ion transporters to avoid ion toxicity.

Jou, Yingtzy; Chiang, Chih-Pin; Yen, Hungchen Emilie

2013-01-01

27

Enhanced thermotolerance of photosystem II in salt-adapted plants of the halophyte Artemisia anethifolia  

Microsoft Academic Search

Thermotolerance of photosystem II (PSII) in leaves of salt-adapted Artemisia anethifolia L. plants (100–400 mM NaCl) was evaluated after exposure to heat stress (30–45°C) for 30 min. After exposure to 30°C, salt adaptation had no effects on the maximal efficiency of PSII photochemistry ( F v\\/ F m), the efficiency of excitation capture by open PSII centers ( F v?\\/ F m?), or

Xiaogang Wen; Nianwei Qiu; Qingtao Lu; Congming Lu

2005-01-01

28

Mineral ion composition of halophytes and associated soils in Western Canada  

Microsoft Academic Search

The mineral ion contents of seven halophytic species in the family Chenopodiaceae, and associated soils were examined. Each species was found growing in soils with wide ranges of salinity, sodicity and salt ion composition. Absolute concentrations of Na, Ca, Mg, K, Cl and SO4 in shoot tissue differed significantly among species. Species were classified into two groups: (1) chloride halophytes,

R. E. Redmann; P. Fedec

1987-01-01

29

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte.  

PubMed

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local 'hotspot' of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost. PMID:24942513

Caperta, Ana D; Espírito-Santo, M Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P; Róis, Ana S; Costa, José C; Arsénio, Pedro

2014-01-01

30

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte  

PubMed Central

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local ‘hotspot’ of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost.

Caperta, Ana D.; Espirito-Santo, M. Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P.; Rois, Ana S.; Costa, Jose C.; Arsenio, Pedro

2014-01-01

31

Conveyor Cultivation of the Halophytic Plant Salicornia europaea for the Recycling of NaCl from Human Liquid Waste in a Biological Life Support System.  

NASA Astrophysics Data System (ADS)

One problem in designing bioregenerative life support systems (BLSS) is developing technolo-gies to include human liquid and solid waste in intrasystem recycling. A specific task is recycling of NaCl excreted in urine by humans. We showed recently that this could be achieved through inclusion of the salt accumulating halophyte Salicornia europaea in the autotrophic compart-ment of the BLSS (Balnokin et al., ASR, 2010, in press). A model of NaCl circulation in BLSS with inclusion of S. europaea was based on the NaCl turnover in the human -urine -nutrient solution -S. europaea -human cycle. Mineralized urine was used as a basis for preparation of a nutrient solution for the halophyte cultivation. The shoots of the halophyte cultivated in the mineralized urine and containing NaCl could to be used by the BLSS inhabitants in their diets. In this report we describe cultivation of S. europaea which allows turnover of NaCl and produces daily shoot biomass containing Na+ and Cl- in quantities approximately equal to those excreted in daily human urine. The plants were grown in water culture in a climatic chamber under controlled conditions. A solution simulating mineralized urine (SSMU) was used as a basis for preparation of a nutri-ent solution for S. europaea cultivation. For continuous biomass production, seedlings of S. europaea, germinated preliminary in moist sand, were being transferred to the nutrient solu-tion at regular intervals (every two days). Duration of the conveyor operation was 112 days. During the first 56 days, the seedlings were being planted in SSMU diluted by a factor of 1.5 (2/3 SSMU). The same solution was introduced into the growth vessels as volumes of growth medium decreased due to plant transpiration. Starting from the 56th day as conveyor operation was initiated, the plants were being harvested every two days; the solutions from the discharged vessels were mixed with the fresh SSMU and the mixture was introduced into all other growth vessels of the conveyor. Thus, during the first 56-d period, the plants grew only in the fresh nutrient solution, whereas during the second 56-d period, the worked out nutrient solutions were being returned into the cycle having been added to the growth vessels along with the fresh SSMU. Growth characteristics, water and ionic relations of S. europaea plants, balance of nutrients between organs and growth media for the first and second 56-d periods of the conveyor operation are presented. There was no significant difference in the rates of shoot biomass production during the first and the second periods. The plants were producing shoot biomass with the rates close to those observed under optimal conditions. However, substantial increase in root biomass production (by 50% on the dry mass basis) was observed in the second period as compared with the first one. Decrease in organ water contents on the dry mass basis (by 13% and 30% for shoots and roots, respectively) and transpiration rates (by 25%) occurred also in the second period as compared with the first one. Measurements of Na+ , Cl- and nutrient contents in the growth media and plant organs and calculation of their balances showed that the plants did not suffer from a deficiency of nutrients during the 112 days of the conveyor operation while accumulating required NaCl amounts. Observed root proliferation and deterioration of water relations in the second 56-d period of the conveyor operation may be caused by toxic plant metabolites exuded by roots into the growth medium.

Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

32

Plant responses to heterogeneous salinity: growth of the halophyte Atriplex nummularia is determined by the root-weighted mean salinity of the root zone  

PubMed Central

Soil salinity is generally spatially heterogeneous, but our understanding of halophyte physiology under such conditions is limited. The growth and physiology of the dicotyledonous halophyte Atriplex nummularia was evaluated in split-root experiments to test whether growth is determined by: (i) the lowest; (ii) the highest; or (iii) the mean salinity of the root zone. In two experiments, plants were grown with uniform salinities or horizontally heterogeneous salinities (10–450mM NaCl in the low-salt side and 670mM in the high-salt side, or 10mM NaCl in the low-salt side and 500–1500mM in the high-salt side). The combined data showed that growth and gas exchange parameters responded most closely to the root-weighted mean salinity rather than to the lowest, mean, or highest salinity in the root zone. In contrast, midday shoot water potentials were determined by the lowest salinity in the root zone, consistent with most water being taken from the least negative water potential source. With uniform salinity, maximum shoot growth was at 120–230mM NaCl; ~90% of maximum growth occurred at 10mM and 450mM NaCl. Exposure of part of the roots to 1500mM NaCl resulted in an enhanced (+40%) root growth on the low-salt side, which lowered root-weighted mean salinity and enabled the maintenance of shoot growth. Atriplex nummularia grew even with extreme salinity in part of the roots, as long as the root-weighted mean salinity of the root zone was within the 10–450mM range.

Bazihizina, Nadia

2012-01-01

33

Plant pathogenic Pseudomonas species  

Microsoft Academic Search

In the current taxonomy, plant pathogenic Pseudomonas species are restricted to rRNA group I organisms belonging to the Gamma subclass of Proteobacteria. Currently, about 21 validly described plant pathogenic Pseudomonas species are known. The most important species is P. syringae with more than 50 described pathovars. The pathovar concept is confusing and the taxonomy of P. syringae needs revision. P.

Monica Höfte; PAUL DE VOS

34

Germination of Dimorphic Seeds of the Desert Annual Halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 Plant without Kranz Anatomy  

PubMed Central

Background and Aims Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Methods Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Key Results Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. Conclusions The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented.

Wang, Lei; Huang, Zhenying; Baskin, Carol C.; Baskin, Jerry M.; Dong, Ming

2008-01-01

35

RING-type ubiquitin ligase McCPN1 catalyzes UBC8-dependent protein ubiquitination and interacts with Argonaute 4 in halophyte ice plant.  

PubMed

RING-type copines are a small family of plant-specific RING-type ubiquitin ligases. They contain an N-terminal myristoylation site for membrane anchoring, a central copine domain for substrate recognition, and a C-terminal RING domain for E2 docking. RING-type copine McCPN1 (copine1) from halophyte ice plant (Mesembryanthemum crystallinum L.) was previously identified from a salt-induced cDNA library. In this work, we characterize the activity, expression, and localization of McCPN1 in ice plant. An in vitro ubiquitination assay of McCPN1 was performed using two ice plant UBCs, McUBC1 and McUBC2, characterized from the same salt-induced cDNA library. The results showed that McUBC2, a member of the UBC8 family, stimulated the autoubiquitination activity of McCPN1, while McUBC1, a homolog of the UBC35 family, did not. The results indicate that McCPN1 has selective E2-dependent E3 ligase activity. We found that McCPN1 localizes primarily on the plasma membrane and in the nucleus of plant cells. Under salt stress, the accumulation of McCPN1 in the roots increases. A yeast two-hybrid screen was used to search for potential McCPN1-interacting partners using a library constructed from salt-stressed ice plants. Screening with full-length McCPN1 identified several independent clones containing partial Argonaute 4 (AGO4) sequence. Subsequent agro-infiltration, protoplast two-hybrid analysis, and bimolecular fluorescence complementation assay confirmed that McCPN1 and AGO4 interacted in vivo in the nucleus of plant cells. The possible involvement of a catalyzed degradation of AGO4 by McCPN1 in response to salt stress is discussed. PMID:24811676

Li, Chang-Hua; Chiang, Chih-Pin; Yang, Jun-Yi; Ma, Chia-Jou; Chen, Yu-Chan; Yen, Hungchen Emilie

2014-07-01

36

Performance of Plants with C 4 -carboxylation Modes of Photosynthesis under Salinity  

Microsoft Academic Search

The C4-carboxylation mode of photosynthetic CO2-fixation expressed in C4- and CAM-plants provides ecophysiological mechanisms for tolerance of drought stress and hence osmotic stress. Therefore,\\u000a one would also expect occurrence of a large diversity of C4- and CAM-plants among halophytes. This, however, is not the case. Halophytes among C4-plants are various grasses and species of Atriplex tolerating salinity by salt extrusion

Ulrich Lüttge

37

Genetically Altered Plant Species  

NASA Technical Reports Server (NTRS)

Researchers in Robert Ferl's lab at the University of Florida in Gainesville, genetically altered this Arabdopsis Thaliana (a brassica species) plant to learn how extreme environments, such as the low atmospheric pressure on Mars, affect plant genes. They inserted green fluorescent protein (GFP) near the on/off switches for anoxia and drought genes. When those genes were turned on after exposure to reduced atmospheric pressure, GFP was turned on as well, causing cells expressing those genes to glow green under a blue light. The natural fluorescence of chlorophyll accounts for the red glow.

2003-01-01

38

EDTA-enhanced phytoremediation of lead-contaminated soil by the halophyte Sesuvium portulacastrum.  

PubMed

The low bioavailability of Pb and low number of Pb-tolerant plant species represent an important limitation for Pb phytoextraction. It was recently suggested that halophyte plant species may be a promising material for this purpose, especially in polluted salt areas while Pb mobility may be improved by synthetic chelating agents. This study aims to evaluate Pb extraction by the halophyte Sesuvium portulacastrum in relation to the impact of EDTA application. Seedling were cultivated during 60 days on Pb artificially contaminated soil (200, 400, and 800 ppm Pb) in the presence or in the absence of EDTA (3 g kg(-1) soil). Results showed that upon to 400 ppm, Pb had no impact on plant growth. However, exogenous Pb induce a decrease in shoot K(+) while it increased shoot Mg(2+) and had no impact on shoot Ca(2+) concentrations. Lead concentration in the shoots increased with increasing external Pb doses reaching 1,390 ppm in the presence of 800 ppm lead in soil. EDTA addition had no effect on plant growth but strongly increased Pb accumulation in the shoot which increased from 1,390 ppm in the absence of EDTA to 3,772 ppm in EDTA-amended plants exposed to 800 ppm exogenous Pb. Both Pb absorption and translocation from roots to shoots were significantly enhanced by EDTA application, leading to an increase in the total amounts of extracted Pb per plant. These data suggest that S. portulacastrum is very promising species for decontamination of Pb(2+)-contaminated soil and that its phytoextraction potential was significantly enhanced by addition of EDTA to the polluted soil. PMID:24604274

Zaier, Hanen; Ghnaya, Tahar; Ghabriche, Rim; Chmingui, Walid; Lakhdar, Abelbasset; Lutts, Stanley; Abdelly, Chedly

2014-06-01

39

Halophytes, Algae, and Bacteria Food and Fuel Feedstocks  

NASA Technical Reports Server (NTRS)

The constant, increasing demand for energy, freshwater, and food stresses our ability to meet these demands within reasonable cost and impact on climate while sustaining quality of life. This environmental Triangle of Conflicts between energy, food, and water--while provoked by anthropogenic monetary and power struggles--can be resolved through an anthropogenic paradigm shift in how we produce and use energy, water, and food. With world population (6.6 billion) projected to increase 40 percent in 40 to 60 yr, proper development of saline agriculture and aquaculture is required, as 43 percent of the Earth's landmass is arid or semi-arid and 97 percent of the Earth's water is seawater. In light of this, we seek fuel alternatives in plants that thrive in brackish and saltwater with the ability to survive in arid lands. The development and application of these plants (halophytes) become the primary focus. Herein we introduce some not-so-familiar halophytes and present a few of their benefits, cite a few research projects (including some on the alternatives algae and bacteria), and then set theoretical limits on biomass production followed by projections in terms of world energy demands. Based on diverse arid lands with a total size equivalent to the Sahara Desert (8.6(exp 8) ha, or 2.1(exp 9) acres), these projections show that halophyte agriculture and algae systems can provide for the projected world energy demand.

Hendricks, R. C.; Bushnell, D. M.

2009-01-01

40

Salt tolerance is related to a specific antioxidant response in the halophyte cordgrass, Spartina densiflora  

NASA Astrophysics Data System (ADS)

Halophytes usually have a robust antioxidative defense system to alleviate oxidative damage during salt stress. Spartina densiflora is a colonizing halophyte cordgrass, native of South America, which has become a common species in salt marshes of northern hemisphere, where it is ousting indigenous species. This study addressed salinity stress in S. densiflora; the occurrence of oxidative stress and the possible involvement of the antioxidative system in its high salt tolerance were studied. Plants were evaluated at in situ conditions, in the laboratory during a 28 day-acclimation period (AP) in clean substrate irrigated with a control salt content of 4 g L-1 (68 mM) and during a subsequent 28 day-treatment period (TP) exposed to different NaCl concentrations: control (68 mM), 428 mM or 680 mM. In the in situ setting, the high leave Na+ content was accompanied by high levels of hydroperoxides and reduced levels of total chlorophyll and carotenes, which correlated with enhanced activation of antioxidant defense biomarkers as total ascorbic acid (AA) content and guaiacol peroxidase (POD: EC 1.11.1.7), catalase (CAT: EC 1.11.1.6) and ascorbate peroxidase (APX: EC 1.11.1.11) activities. Throughout the AP, leave Na+ and oxidative stress markers decreased concomitantly and reached stable low levels. During the TP, dose and time-dependent accumulation of Na+ in high NaCl-treated plants was concurrent with a decrease in content of total chlorophyll and carotenes and with an increase in the levels of total AA and CAT and APX activities. In conclusion, as hypothesized, high salinity induces conditions of oxidative stress in S. densiflora, so that its salt tolerance appears to be related to the implementation of a specific antioxidant response. This may account for Spartina densiflora's successful adaptation to habitats with fluctuating salinity and favour its phytoremediation potential.

Canalejo, Antonio; Martínez-Domínguez, David; Córdoba, Francisco; Torronteras, Rafael

2014-06-01

41

Seeding conditions of the halophyte Atriplex patula for optimal growth on a salt impacted site.  

PubMed

Salt-impacted soils resulting from oilfield brine spills are increasingly becoming a significant problem in oil-producing areas of Canada such as Alberta and Saskatchewan. The native halophyte Atriplex patula is being considered a potential species for phytoremediation of brine-impacted sites in these hemiboreal climactic zones. The objective of this study was to investigate the optimal seeding conditions under field conditions (with no irrigation) of A. patula for phytoremediation of salt from a brine-impacted site. Atriplex patula was identified in preliminary greenhouse trials to have one of the highest salt accumulations in relation to plant yields. Different seeding methods of A. patula were assessed in an attempt to achieve reproducible growth of this species. While plant yields for A. patula were improved on compacted soil by approximately 30-50%, growth was uneven with regard to density and height. The uneven growth may be due to seed quality and low precipitation during the field season, while improvements in plant yield on compact soil might be due to a lack of competition with other species. PMID:21972494

Young, Michelle A; Rancier, Doug G; Roy, Julie L; Lunn, Stuart R; Armstrong, Sarah A; Headley, John V

2011-08-01

42

A salinity-induced gene from the halophyte M. crystallinum encodes a glycolytic enzyme, cofactor-independent phosphoglyceromutase  

Microsoft Academic Search

In the facultative halophyte Mesembryanthemum crystallinum (ice plant), salinity stress triggers significant changes in gene expression, including increased expression of mRNAs encoding enzymes involved with osmotic adaptation to water stress and the crassulacean acid metabolism (CAM) photosynthetic pathway. To investigate adaptive stress responses in the ice plant at the molecular level, we generated a subtracted cDNA library from stressed plants

Nancy R. Forsthoefel; Daniel M. Vernon; John C. Cushman

1995-01-01

43

Investigation of Vegetation Species in Desert Areas of Fars Province  

NASA Astrophysics Data System (ADS)

The Fars province is located in the south of IRAN, with area of 122830Km2. This areas involved saline and alkaline soils. The aim of this research is investigation of salty lands and vegetation degradation for offering of sociable species for any area. Recognition studying of desert area in Fars province was identified using all available data and using GIS and RS technologies. In this study, main indicators have been appointed using Floristical-Fizionomicaly method. Vegetation per cent, growth form, density and altitude were considered as main indicators. More than 50 species of halophytes were collected and 25 plant types were identified in 17 zones of studied area. The main plant types were as follows: Hammada, Halocnemum-Aeluropus and Halocnemum-limonium. Ultimately, halophytes cover map was prepared. In the end of growth season, 50 soil samples from halophyte types in two horizons 0-30cm and 30-100cm were taken and tested. The result showed, the studied area, has saline lands surface and high salinity land with cover of 9000Km2. Keyword: Saline Soil, Alkaline Soil, Halophytes, Fars Province

Fozoni, L.; Fakhireh, A.

2009-04-01

44

Mangroves: obligate or facultative halophytes? A review  

Microsoft Academic Search

Salinity plays significant roles in regulating the growth and distribution of mangroves, and the salt tolerance mechanisms\\u000a of mangroves have been the focus of research for several decades. There are contradictory views regarding the relationship\\u000a between mangroves and salt: (1) Mangroves are facultative halophytes, i.e. freshwater is a physiological requirement and salt\\u000a water is an ecological requirement for mangroves because

Wenqing Wang; Zhongzheng Yan; Siyang You; Yihui Zhang; Luzhen Chen; Guanghui Lin

45

Tolerance of combined submergence and salinity in the halophytic stem-succulent Tecticornia pergranulata  

PubMed Central

Background and Aims Habitats occupied by many halophytes are not only saline, but are also prone to flooding. Few studies have evaluated submergence tolerance in halophytes. Methods Responses to submergence, at a range of salinity levels, were studied for the halophytic stem-succulent Tecticornia pergranulata subsp. pergranulata (syn. Halosarcia pergranulata subsp. pergranulata). Growth and total sugars in succulent stems were assessed as a function of time after submergence. Underwater net photosynthesis, dark respiration, total sugars, glycinebetaine, Na+, Cl? and K+, in succulent stems, were assessed in a NaCl dose-response experiment. Key Results Submerged plants ceased to grow, and tissue sugars declined. Photosynthesis by succulent stems was reduced markedly when underwater, as compared with in air. Capacity for underwater net photosynthesis (PN) was not affected by 10–400 mm NaCl, but it was reduced by 30 % at 800 mm. Dark respiration, underwater, increased in succulent stems at 200–800 mm NaCl, as compared with those at 10 mm NaCl. On an ethanol-insoluble dry mass basis, K+ concentration in succulent stems of submerged plants was equal to that in drained controls, across all NaCl treatments. Na+ and Cl? concentrations, however, were elevated in stems of submerged plants, but so was glycinebetaine. Submerged stems increased in succulence, so solutes would have been ‘diluted’ on a tissue-water basis. Conclusions Tecticornia pergranulata tolerates complete submergence, even in waters of high salinity. A ‘quiescence response’, i.e. no shoot growth, would conserve carbohydrates, but tissue sugars still declined with time. A low K+ : Na+ ratio, typical for tissues of succulent halophytes, was tolerated even during prolonged submergence, as evidenced by maintenance of underwater PN at up to 400 mm NaCl. Underwater PN provides O2 and sugars, and thus should enhance survival of submerged plants.

Colmer, T. D.; Vos, H.; Pedersen, O.

2009-01-01

46

Endangered Species (Plants). LC Science Tracer Bullet.  

ERIC Educational Resources Information Center

This guide is intended for those who wish to study the literature dealing with various aspects of endangered plant species. This document includes the following sections, some of which are bibliographies: (1) "Introductions to the Topic"; (2) "Subject Headings" (for endangered species of plants used by the Library of Congress); (3) "General…

Niskern, Diana, Comp.

47

The Invasive Plant Species Education Guide  

NSDL National Science Digital Library

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS

D'Angelo, Jean; Mason, Kevin; Carlson, Kitrina; James, Krista

2010-04-01

48

The Invasive Plant Species Education Guide  

ERIC Educational Resources Information Center

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

2010-01-01

49

Why Some Plant Species Are Rare  

PubMed Central

Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic) gradients within ecosystems is particularly important for preserving rare species.

Wamelink, G. W. Weiger; Goedhart, Paul W.; Frissel, Josep Y.

2014-01-01

50

Reduced tonoplast fast-activating and slow-activating channel activity is essential for conferring salinity tolerance in a facultative halophyte, quinoa.  

PubMed

Halophyte species implement a "salt-including" strategy, sequestering significant amounts of Na(+) to cell vacuoles. This requires a reduction of passive Na(+) leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na(+)-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na(+) accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na(+) exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na(+) sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na(+), this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K(+) than for Na(+), and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 mm NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and salt-grown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na(+) leak, thus enabling efficient sequestration of Na(+) to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species. PMID:23624857

Bonales-Alatorre, Edgar; Shabala, Sergey; Chen, Zhong-Hua; Pottosin, Igor

2013-06-01

51

Extinction risks of Amazonian plant species  

PubMed Central

Estimates of the number, and preferably the identity, of species that will be threatened by land-use change and habitat loss are an invaluable tool for setting conservation priorities. Here, we use collections data and ecoregion maps to generate spatially explicit distributions for more than 40,000 vascular plant species from the Amazon basin (representing more than 80% of the estimated Amazonian plant diversity). Using the distribution maps, we then estimate the rates of habitat loss and associated extinction probabilities due to land-use changes as modeled under 2 disturbance scenarios. We predict that by 2050, human land-use practices will have reduced the habitat available to Amazonian plant species by ?12–24%, resulting in 5–9% of species becoming “committed to extinction,” significantly fewer than other recent estimates. Contrary to previous studies, we find that the primary determinant of habitat loss and extinction risk is not the size of a species' range, but rather its location. The resulting extinction risk estimates are a valuable conservation tool because they indicate not only the total percentage of Amazonian plant species threatened with extinction but also the degree to which individual species and habitats will be affected by current and future land-use changes.

Feeley, Kenneth J.; Silman, Miles R.

2009-01-01

52

Extinction risks of Amazonian plant species.  

PubMed

Estimates of the number, and preferably the identity, of species that will be threatened by land-use change and habitat loss are an invaluable tool for setting conservation priorities. Here, we use collections data and ecoregion maps to generate spatially explicit distributions for more than 40,000 vascular plant species from the Amazon basin (representing more than 80% of the estimated Amazonian plant diversity). Using the distribution maps, we then estimate the rates of habitat loss and associated extinction probabilities due to land-use changes as modeled under 2 disturbance scenarios. We predict that by 2050, human land-use practices will have reduced the habitat available to Amazonian plant species by approximately 12-24%, resulting in 5-9% of species becoming "committed to extinction," significantly fewer than other recent estimates. Contrary to previous studies, we find that the primary determinant of habitat loss and extinction risk is not the size of a species' range, but rather its location. The resulting extinction risk estimates are a valuable conservation tool because they indicate not only the total percentage of Amazonian plant species threatened with extinction but also the degree to which individual species and habitats will be affected by current and future land-use changes. PMID:19617552

Feeley, Kenneth J; Silman, Miles R

2009-07-28

53

Silicon alleviates deleterious effects of high salinity on the halophytic grass Spartina densiflora.  

PubMed

The non-essential element silicon is known to improve plant fitness by alleviating the effects of biotic and abiotic stresses, particularly in crops. However, its possible role in the exceptional tolerance of halophytes to salinity has not been investigated. This study reports the effect of Si supply on the salinity tolerance of the halophytic grass Spartina densiflora; plants were treated with NaCl (0-680 mM), with or without silicon addition of 500 ?M, in a glasshouse experiment. Plant responses were examined using growth analysis, combined with measurements of gas exchange, chlorophyll fluorescence and photosynthetic pigment concentrations. In addition, tissue concentrations of aluminium, calcium, copper, iron, potassium, magnesium, sodium, phosphorus and silicon were determined. Although high salinity decreased growth, this effect was alleviated by treatment with Si. Improved growth was associated with higher net photosynthetic rate (A), and greater water-use efficiency (WUE). Enhanced A at high salinity could be explained by beneficial effects of Si on the photochemical apparatus, and on chlorophyll concentrations. Ameliorative effects of Si were correlated with reduced sodium uptake, which was unrelated to a reduction in the transpiration rate, since Si-supplemented plants had higher stomatal conductances (G(s)). These plants also had higher tissue concentrations of essential nutrients, suggesting that Si had a positive effect on the mineral nutrient balance in salt-stressed plants. Si appears to play a significant role in salinity tolerance even in a halophyte, which has other, specific salt-tolerance mechanisms, through diverse protective effects on the photosynthetic apparatus, water-use efficiency and mineral nutrient balance. PMID:23257076

Mateos-Naranjo, Enrique; Andrades-Moreno, Luis; Davy, Anthony J

2013-02-01

54

Ensemble habitat mapping of invasive plant species.  

PubMed

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. PMID:20136746

Stohlgren, Thomas J; Ma, Peter; Kumar, Sunil; Rocca, Monique; Morisette, Jeffrey T; Jarnevich, Catherine S; Benson, Nate

2010-02-01

55

Ensemble habitat mapping of invasive plant species  

USGS Publications Warehouse

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. ?? 2010 Society for Risk Analysis.

Stohlgren, T. J.; Ma, P.; Kumar, S.; Rocca, M.; Morisette, J. T.; Jarnevich, C. S.; Benson, N.

2010-01-01

56

Evidence for electrotropism in some plant species.  

PubMed

The ever-present global Atmospheric Electrical Field (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity of electrotropic effect to different electric field intensities. During a few years, it was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions. The "reference field" (130 V/m) was always used with stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed and horizontal field polarity. In conclusion electrotropic plants deprived of the electrical field do not develop as expected, as can be seen in Biosphere 2. This is an instructive example of what happens when we forget to provide the plants with this vital natural environmental factor. Electrical fields of different intensity, directions and configurations are cheap and easy to generate. PMID:11803965

Gorgolewski, S; Rozej, B

2001-01-01

57

Evidence for electrotropism in some plant species  

NASA Astrophysics Data System (ADS)

The ever-present global Atmospheric Electrical Field (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity of electrotropic effect to different electric field intensities. During a few years, it was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions. The "reference field" (130 V/m) was always used with stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed and horizontal field polarity. In conclusion electrotropic plants deprived of the electrical field do not develop as expected, as can be seen in Biosphere 2. This is an instructive example of what happens when we forget to provide the plants with this vital natural environmental factor. Electrical fields of different intensity, directions and configurations are cheap and easy to generate.

Gorgolewski, S.; Ro?ej, B.

2001-01-01

58

Methane dynamics across wetland plant species  

Microsoft Academic Search

We examined patterns of methane flux, plant biomass, and microbial methanogenic populations in nine wetland plant species. Methane dynamics varied across plant functional groupings, with patterns distinctive among forbs, clonal dominants, and tussock\\/clump-forming graminoids. Carex stricta and Scirpus atrovirens showed the highest emissions (31.7 and 20.6mgCH4-Cm?2h?1), followed by other tussock- or clump-forming graminoids that averaged 11.0mgCH4-Cm?2h?1 (Scirpus cyperinus, Glyceria striata,

Jenny Kao-Kniffin; Dominique S. Freyre; Teri C. Balser

2010-01-01

59

Heterogeneous distribution of metabolites across plant species  

NASA Astrophysics Data System (ADS)

We investigate the distribution of flavonoids, a major category of plant secondary metabolites, across species. Flavonoids are known to show high species specificity, and were once considered as chemical markers for understanding adaptive evolution and characterization of living organisms. We investigate the distribution among species using bipartite networks, and find that two heterogeneous distributions are conserved among several families: the power-law distributions of the number of flavonoids in a species and the number of shared species of a particular flavonoid. In order to explain the possible origin of the heterogeneity, we propose a simple model with, essentially, a single parameter. As a result, we show that two respective power-law statistics emerge from simple evolutionary mechanisms based on a multiplicative process. These findings provide insights into the evolution of metabolite diversity and characterization of living organisms that defy genome sequence analysis for different reasons.

Takemoto, Kazuhiro; Arita, Masanori

2009-07-01

60

Leaf trait relationships in Australian plant species  

Microsoft Academic Search

Leaf trait data were compiled for 258 Australian plant species from several habitat types dominated by woody perennials. Specific leaf area (SLA), photosynthetic capacity, dark respiration rate and leaf nitrogen (N) and phosphorus (P) concentrations were positively correlated with one another and negatively correlated with average leaf lifespan. These trait relationships were consistent with previous results from global datasets. Together,

Ian J. Wright; Philip K. Groom; Byron B. Lamont; Pieter Poot; Peter B. Reich; E-Detlef Schulze; Erik J. Veneklaas; Mark Westoby; Penrith South

2004-01-01

61

Plant species descriptions show signs of disease.  

PubMed

It is well known that diseases can greatly influence the morphology of plants, but often the incidence of disease is either too rare or the symptoms too obvious for the 'abnormalities' to cause confusion in systematics. However, we have recently come across several misinterpretations of disease-induced traits that may have been perpetuated into modern species inventories. Anther-smut disease (caused by the fungus Microbotryum violaceum) is common in many members of the Caryophyllaceae and related plant families. This disease causes anthers of infected plants to be filled with dark-violet fungal spores rather than pollen. Otherwise, their vegetative morphology is within the normal range of healthy plants. Here, we present the results of a herbarium survey showing that a number of type specimens (on which the species name and original description are based) in the genus Silene from Asia are diseased with anther smut. The primary visible disease symptom, namely the dark-violet anthers, is incorporated into the original species descriptions and some of these descriptions have persisted unchanged into modern floras. This raises the question of whether diseased type specimens have erroneously been given unique species names. PMID:14667368

Hood, Michael E; Antonovics, Janis

2003-11-01

62

Assessment of the potential of halophytes as energy crops for the electric utility industry. Final report  

SciTech Connect

This technical report assesses and estimates the potential of selected halophytes as future renewable energy resources, especially by US electric utilities, and familiarizes nonspecialists with research and development problems that must be resolved before these energy sources can become dependable supplies of energy. A literature search related to both indigenous and exotic species of halophytes has been done and appropriate terrestrial species have been selected. Selection criteria include: total biomass potential, genetic constraints, establishment and cultivation requirements, regions of suitability, secondary credits, and a number of other factors. Based on these selection criteria, for the arid western states with high levels of salinity in water and/or soils, there is little potential for energy feedstocks derived from grasses and herbaceous forbs. Likewise, coastal marshes, estuaries, and mangrove swamps, although excellent biomass producers, are too limited by region and have too many ecological and environmental problems for consideration. The deep-rooted, perennial woody shrubs indigenous to many saline regions of the west provide the best potential. The number of species in this group is limited, and Atriplex canescens, Sarcobatus vermiculatus, and Chrysothamnus nauseosus are the three species with the greatest biological potential. These shrubs would receive minimal energy inputs in cultivation, would not compete with agricultural land, and would restore productivity to severely disturbed sites. One might logically expect to achieve biomass feedstock yields of three to five tons/acre/yr on a long-term sustainable basis. The possibility also exists that exotic species might be introduced. 67 references, 1 figure, 5 tables.

Goodin, J.R.

1984-09-01

63

A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum.  

PubMed

Molecular mechanisms of osmotic stress tolerance were studied in Mesembryanthemum crystallinum (ice plant), a facultative halophyte capable of adjusting to and surviving in highly saline conditions. We screened a subtracted cDNA library enriched for salt stress-induced mRNAs to identify transcripts involved in this plant's adaptation to salinity. One mRNA, Imt1, was found to be up-regulated in leaves and, transiently, in roots. Nuclear run-on assays indicated that this mRNA is transcriptionally regulated. Imt1 encoded a predicted polypeptide of M(r) 40,250 which exhibited sequence similarity to several hydroxymethyl transferases. Expression of the protein in Escherichia coli and subsequent activity assays identified the protein as a novel myoinositol O-methyl transferase which catalyzes the first step in the biosynthesis of the cyclic sugar alcohol pinitol. Pinitol accumulates in salt-stressed M.crystallinum and is abundant in a number of salt- and drought-tolerant plants. The presence of high levels of sugar alcohols correlates with osmotolerance in a diverse range of organisms, including bacteria, fungi and algae, as well as higher plants. The stress-initiated transcriptional induction of IMT1 expression in a facultative halophyte provides strong support for the importance of sugar alcohols in establishing tolerance to osmotic stress in higher plants. PMID:1600940

Vernon, D M; Bohnert, H J

1992-06-01

64

Technical Note: Seeding Conditions of the Halophyte Atriplex Patula for Optimal Growth on a Salt Impacted Site  

Microsoft Academic Search

Salt-impacted soils resulting from oilfield brine spills are increasingly becoming a significant problem in oil-producing areas of Canada such as Alberta and Saskatchewan.The native halophyte Atriplex patula is being considered a potential species for phytoremediation of brine-impacted sites in these hemiboreal climactic zones. The objective of this study was to investigate the optimal seeding conditions under field conditions (with no

Michelle A. Young; Doug G. Rancier; Julie L. Roy; Stuart R. Lunn; Sarah A. Armstrong; John V. Headley

2011-01-01

65

Leaf–water relations and ion concentrations of the halophyte Atriplex hortensis in response to salinity and water stress  

Microsoft Academic Search

The impact of salinity and water stress was analyzed in the xero-halophyte Atriplex hortensis using two varieties: green orach (A. hortensis var. purpurea) and red orach (A. hortensis var. rubra). A. hortensis L. is a C3 species well adapted to salt and drought conditions. To collect information on the physiological impact of different salt\\u000a and water deficit levels on their

S. Sai Kachout; A. Ben Mansoura; K. Jaffel Hamza; J. C. Leclerc; M. N. Rejeb; Z. Ouerghi

2011-01-01

66

Flavonoids from the halophyte Apocynum venetum and their antifouling activities against marine biofilm-derived bacteria.  

PubMed

Eleven flavonoids were isolated from the leaves of the halophyte Apocynum venetum. Among them, the isolation of plumbocatechin A (1), 8-O-methylretusin (2) and kaempferol 3-O-(6?-O-acetyl)-?-d-galactopyranoside (7) was reported for the first time from this plant. Their structures were identified by using spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In addition, the antifouling activities of these compounds against the marine fouling bacteria, Bacillus thuringiensis, Pseudoalteromonas elyakovii and Pseudomonas aeruginosa, have been evaluated in this article. PMID:24588258

Kong, Na-Na; Fang, Sheng-Tao; Liu, Ying; Wang, Jian-Hua; Yang, Cui-Yun; Xia, Chuan-Hai

2014-06-01

67

Saturation Deficit of the Mesophyll Evaporating Surfaces in a Desert Halophyte.  

PubMed

The tensions developed in the internal evaporating leaf surfaces were estimated for a desert halophyte, Reaumuria hirtella, growing in its natural habitat. The method was based on the assumption that at zero transpiration the vapor pressure of the inner parts of the leaf was in equilibrium with that of the atmosphere, provided that stomatal resistance was constant during the measuring period. This could be ensured, since the measuring system controlled both the concentration of carbon dioxide and the atmospheric humidity, while measuring photosynthesis and transpiration simultaneously. Tension values of 180, 240, and 320 bars were recorded for three different Reaumuria hirtella plants. PMID:17810148

Whiteman, P C; Koller, D

1964-12-01

68

Plant species intermediate for c3, c4 photosynthesis.  

PubMed

Mollugo verticillata is the first plant species reported which has characteristics of both C(3) (Calvin-Benson pathway) and C(4) (Hatch-Slack pathway) plants. This plant species is intermediate between C(3) and C(4) plants in at least four features generally used to separate those two plant groups: leaf anatomy, cell ultrastructure, photorespiration, and primary photosynthetic products. PMID:17736195

Kennedy, R A; Laetsch, W M

1974-06-01

69

Plant Species Intermediate for C3, C4 Photosynthesis  

Microsoft Academic Search

Mollugo verticillata is the first plant species reported which has characteristics of both C3 (Calvin-Benson pathway) and C4 (Hatch-Slack pathway) plants. This plant species is intermediate between C3 and C4 plants in at least four features generally used to separate those two plant groups: leaf anatomy, cell ultrastructure, photorespiration, and primary photosynthetic products.

R. A. Kennedy; W. M. Laetsch

1974-01-01

70

Factors associated with determination of root ²²Na (+) influx in the salt accumulation halophyte Suaeda maritima.  

PubMed

Salinity is an increasing problem for agricultural production worldwide. The result of low-affinity Na(+) uptake is toxic to the cytoplasm of most crop plants. Nevertheless, the pathways for this low-affinity Na(+) uptake are still uncertain. In this work we used ²²Na(+) isotope tracing technology to investigate factors associated with determination of root ²²Na(+) influx in the salt accumulation halophyte Suaeda maritima. We found that a 2 min of exposure to the ²²Na(+) labeled uptake solution was optimal for determining ²²Na(+) influx into excised roots of S. maritima and that 7 min of blotting is suitable in ²²Na(+) influx experiments. ²²Na(+) influx did not increase linearly with the increasing external Na(+) concentration, in the range tested, of 2 to 300 mM NaCl. But root ²²Na(+) influx and root Na(+) concentration were well correlated. ²²Na(+) influx into excised roots of S. maritima was not, however, well correlated with the plant size. All the above results indicated further that this ²²Na(+) isotope influx procedure is a good method for quantify Na(+) uptake rate by the roots of the salt accumulation halophyte. PMID:20217274

Zhang, Jin-Lin; Wetson, Anne M; Wang, Suo-Min; Gurmani, Ali R; Bao, Ai-Ke; Wang, Chun-Mei

2011-01-01

71

Interactions Among Grassland Plant Species, Microbial Communities, and Soil Processes  

Microsoft Academic Search

Plant-microbial interactions are thought to be an important determinant of ecosystem processes, yet we do not know whether impacts of plant species on soil microbial community composition translate to impacts on function. We established field plots in a California annual grassland of five plant monocultures for two years to determine the effects of different plant species on the composition of

V. Eviner; M. Waldrop; E. Schwartz; J. Pett-Ridge; M. Firestone

2002-01-01

72

Ecophysiological adaptations of coastal halophytes from foredunes and salt marshes  

Microsoft Academic Search

Ecophysiological strategies of coastal halophytes from foredunes and salt marshes are discussed. A comparison is made of the factors that limit growth in salt marshes and sand dunes. In salt marshes, zonation and succession are primarily governed by variation in soil salinity, which strongly depends on inundation with seawater. Results are described of experiments which aim at separating salinity and

J. Rozema; P. Bijwaard; G. Prast; R. Broekman

1985-01-01

73

Metal phytoremediation by the halophyte Limoniastrum monopetalum (L.) Boiss: two contrasting ecotypes.  

PubMed

The phytoremediation potential of the halophyte Limoniastrum monopetalum for the removal of Cd and Pb from polluted sites is assessed in this work. Two pot experiments were conducted; the first with wild L. monopetalum grown on soil polluted with Cd and Pb irrigated at different salinities, and the second with commonly cultivated ornamental L. monopetalum grown on soil polluted with Cd irrigated also at different salinities. The data revealed that wild L. monopetalum is a Cd and Pb tolerant plant able to accumulate at least 100 ppm of cadmium in its shoots without showing any significant decrease in terms of biomass production, chlorophyll content or water content suggesting that it could be an accumulator of Cd. Pb above-ground accumulation was kept at low levels with the majority of Pb localized in the roots. On the other hand, contrasting results were obtained for ornamental L. monopetalum which although it was found to be also Cd tolerant, Cd accumulation in its tissues was kept at significantly lower levels especially compared to that of the wild ecotype. In addition for ornamental L. monopetalum salinity did not have a positive effect on Cd accumulation and translocation as observed in the wild type and in other halophytes. Analysis of the salt excretion crystals on the leaf surface confirmed that wild and cultivated ornamental L. monopetalum excrete cadmium and lead through their salt glands as a possible metal detoxification mechanism, although the amount excreted by the ornamental L. monopetalum is significantly less. PMID:24933883

Manousaki, Eleni; Galanaki, Kosmoula; Papadimitriou, Lamprini; Kalogerakis, Nicolas

2014-01-01

74

Northeast Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The USDA Natural Resource Conservation Service's Northeast National Technical Center in Chester, Pennsylvania produced Northeast Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

75

Southern Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The US Department of Agriculture's (USDA) Soil Conservation Service branch in Fort Worth, Texas produced the Southern Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

76

Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city  

USGS Publications Warehouse

Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l-1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ETo) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ETo in summer and equal to or slightly greater than ETo in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important. ?? 2008 Elsevier B.V.

Glenn, E. P.; Mckeon, C.; Gerhart, V.; Nagler, P. L.; Jordan, F.; Artiola, J.

2009-01-01

77

Over expression of cytosolic copper\\/zinc superoxide dismutase from a mangrove plant Avicennia marina in indica Rice var Pusa Basmati1 confers abiotic stress tolerance  

Microsoft Academic Search

Antioxidant enzymes play an important role in conferring abiotic stress tolerance. Superoxide dismutase (SOD) is the first\\u000a enzyme in the enzymatic antioxidative pathway. Halophytic plants like mangroves have been reported to have a high level of\\u000a SOD activity, which plays a major role in defending the mangrove species against severe abiotic stresses. We had previously\\u000a reported the isolation of Sod1,

S. R. Prashanth; V. Sadhasivam; Ajay Parida

2008-01-01

78

Differences in proton pumping and Na/H exchange at the leaf cell tonoplast between a halophyte and a glycophyte  

PubMed Central

The tonoplast Na+/H+ antiporter and tonoplast H+ pumps are essential components of salt tolerance in plants. The objective of this study was to investigate the transport activity of the tonoplast Na+/H+ antiporter and the tonoplast V-H+-ATPase and V-H+-PPase in a highly tolerant salt-accumulating halophyte, Salicornia dolichostachya, and to compare these transport activities with activities in the related glycophyte Spinacia oleracea. Vacuolar membrane vesicles were isolated by density gradient centrifugation, and the proton transport and hydrolytic activity of both H+ pumps were studied. Furthermore, the Na+/H+-exchange capacity of the vesicles was investigated by 9-amino-6-chloro-2-methoxyacridine fluorescence. Salt treatment induced V-H+-ATPase and V-H+-PPase activity in vesicles derived from S. oleracea, whereas V-H+-ATPase and V-H+-PPase activity in S. dolichostachya was not affected by salt treatment. Na+/H+-exchange capacity followed the same pattern, i.e. induced in response to salt treatment (0 and 200 mM NaCl) in S. oleracea and not influenced by salt treatment (10 and 200 mM NaCl) in S. dolichostachya. Our results suggest that S. dolichostachya already generates a high tonoplast H+ gradient at low external salinities, which is likely to contribute to the high cellular salt accumulation of this species at low external salinities. At high external salinities, S. dolichostachya showed improved growth compared with S. oleracea, but V-H+-ATPase, V-H+-PPase and Na+/H+-exchange activities were comparable between the species, which might imply that S. dolichostachya more efficiently retains Na+ in the vacuole.

Katschnig, Diana; Jaarsma, Rinse; Almeida, Pedro; Rozema, Jelte; Schat, Henk

2014-01-01

79

Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels  

NASA Technical Reports Server (NTRS)

Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, OH, Oct. 17 to 18, 2007 (ref. 1).

Hendricks, R. C.

2007-01-01

80

Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels  

NASA Technical Reports Server (NTRS)

Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

Hendricks, R. C.

2012-01-01

81

Osmotic adjustment, water relations and growth attributes of the xero-halophyte Reaumuria vermiculata L. (Tamaricaceae) in response to salt stress  

Microsoft Academic Search

Reaumuria vermiculata (L.), a perennial dwarf shrub in the family of Tamaricaceae, is a salt-secreting xero-halophyte found widely in arid areas\\u000a of Tunisia. In the present study, physiological attributes of R. vermiculata were investigated under salt stress. Four-month-old plants were subjected to various salinity levels (0, 100, 200, 300, 400\\u000a or 600 mM NaCl) for 30 days under greenhouse conditions. Results showed

Mustapha Gorai; Mohamed Neffati

2011-01-01

82

Nutrient relations of the halophytic shrub, Sarcobatus vermiculatus, along a soil salinity gradient  

Microsoft Academic Search

Recent water level declines of a saline and alkaline lake (Mono Lake, California, USA) have exposed large areas of former lake bottom substrates that have been sparsely colonized by the halophytic shrub, Sarcobatus vermiculatus. To increase understanding of the interaction of salt and nutrient relations in halophytes we investigated spatial and seasonal patterns of leaf elemental composition and growth for

Lisa A. Donovan; James H. Richards; E. Joy Schaber

1997-01-01

83

Plant DNA barcodes and species resolution in sedges ( Carex , Cyperaceae)  

Microsoft Academic Search

We investigate the species discriminatory power of a subset of the proposed plant barcoding loci (matK, rbcL, rpoC1, rpoB, trnH-psbA) in Carex, a cosmopolitan genus that represents one of the three largest plant genera on earth (c. 2000 species). To assess the ability of barcoding loci to resolve Carex species, we focused our sampling on three of the taxonomically best-

JULIAN R. STARR; ROBERT F. C. NACZI; BRIANNA N. CHOUINARD

2009-01-01

84

Export of Plant and Animal Species from an Insular Biota  

Microsoft Academic Search

The deliberate and accidental establishment of exotic species in New Zealand is widely known. However, increasingly New Zealand native species are being introduced in other temperate regions of the world, and a significant proportion has become invasive. This chapter describes the establishment of native New Zealand plant and animal species elsewhere, and discusses the (varied) reasons for their success as

G. W. Yeates; P. A. Williams

85

Exotic plants increase and native plants decrease with loss of foundation species in sagebrush steppe  

Microsoft Academic Search

Dominant plant species, or foundation species, are recognized to have a disproportionate control over resources in ecosystems,\\u000a but few studies have evaluated their relationship to exotic invasions. Loss of foundation species could increase resource\\u000a availability to the benefit of exotic plants, and could thereby facilitate invasion. The success of exotic plant invasions\\u000a in sagebrush steppe was hypothesized to benefit from

Janet S. Prevéy; Matthew J. Germino; Nancy J. Huntly; Richard S. Inouye

2010-01-01

86

Evaluating plant invasions from both habitat and species perspectives  

USGS Publications Warehouse

We present an approach to quantitatively assess nonnative plant invasions at landscape scales from both habitat and species perspectives. Our case study included 34 nonnative species found in 142 plots (0.1 ha) in 14 vegetation types within the Grand Staircase-Escalante National Monument, Utah. A plot invasion index, based on nonnative species richness and cover, showed that only 16 of 142 plots were heavily invaded. A species invasive index, based on frequency, cover, and number of vegetation types invaded, showed that only 7 of 34 plant species were highly invasive. Multiple regressions using habitat characteristics (moisture index, elevation, soil P, native species richness, maximum crust development class, bare ground, and rock) explained 60% of variation in nonnative species richness and 46% of variation in nonnative species cover. Three mesic habitats (aspen, wet meadow, and perennial riparian types) were particularly invaded (31 of 34 nonnative species studied were found in these types). Species-specific logistic regression models for the 7 most invasive species correctly predicted occurrence 89% of the time on average (from 80% for Bromus tectorum, a habitat generalist, to 93% for Tamarix spp., a habitat specialist). Even with such a modest sampling intensity (<0.1% of the landscape), this multiscale sampling scheme was effective at evaluating habitat vulnerability to invasion and the occurrence of the 7 most invasive nonnative species. This approach could be applied in other natural areas to develop strategies to document invasive species and invaded habitats.

Chong, G. W.; Otsuki, Y.; Stohlgren, T. J.; Guenther, D.; Evangelista, P.; Villa, C.; Waters, A.

2006-01-01

87

Human population, grasshopper and plant species richness in European countries  

NASA Astrophysics Data System (ADS)

Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

Steck, Claude E.; Pautasso, Marco

2008-11-01

88

Widespread plant species: natives vs. aliens in our changing world  

USGS Publications Warehouse

Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments.

Stohlgren, Thomas J.; Pyšek, Petr; Kartesz, John; Nishino, Misako; Pauchard, Aníbal; Winter, Marten; Pino, Joan; Richardson, David M.; Wilson, John R. U.; Murray, Brad R.; Phillips, Megan L.; Ming-yang, Li; Celesti-Grapow, Laura; Font, Xavier

2011-01-01

89

Interactions Among Grassland Plant Species, Microbial Communities, and Soil Processes  

NASA Astrophysics Data System (ADS)

Plant-microbial interactions are thought to be an important determinant of ecosystem processes, yet we do not know whether impacts of plant species on soil microbial community composition translate to impacts on function. We established field plots in a California annual grassland of five plant monocultures for two years to determine the effects of different plant species on the composition of the bulk soil microbial community and selected soil processes. Plant species were associated with distinct ecosystem process rates such as net nitrogen mineralization, nitrification, decomposition and soil respiration. Bacterial community substrate utilization profiles differed among different plant species and were related to labile soil C. DNA-based fingerprints of bacterial, ammonia oxidizer, and fungal communities did not generally differ in soils planted to different species; however, these microbial community profiles did strongly correlate to rates of decomposition. Terminal Restriction Fragment Length Polymorphism (TRFLP) analysis of soil microbial communities showed that the lupine community was distinct from the other four plant-associated communities. Phospholipid fatty acid (PLFA) patterns also failed to distinguish differences in the overall microbial communities associated with the five different moncultures. Interestingly, PLFA biomarker 16:1w5, indicative of AM fungi, differed among plant species treatments. This PLFA biomarker and bacterial TRFLP patterns were related to decomposition rates of a common litter. In summary, large functional differences were found between field plots with different plant species and the composition of the microbial communities was closely related to some of the functions assessed, independent of plant species. Only small plant-induced changes in microbial community composition were detected, yet apparently these changes had significant impact on function. Our analyses were not specifically targeted to microsites with high activity (such as rhizosphere soil) and our DNA and PLFA-based analyses included a potentially huge "dormant" community of soil microorganisms. While our analyses could detect little impact of plant species on overall microbial community profiles, a smaller active-fraction of the soil microbial community may have been more significantly affected.

Eviner, V.; Waldrop, M.; Schwartz, E.; Pett-Ridge, J.; Firestone, M.

2002-12-01

90

Genetic diversity within a dominant plant outweighs plant species diversity in structuring an arthropod community.  

PubMed

Plant biodiversity is being lost at a rapid rate. This has spurred much interest in elucidating the consequences of this loss for higher trophic levels. Experimental tests have shown that both plant species diversity and genetic diversity within a plant species can influence arthropod community structure. However, the majority of these studies have been conducted in separate systems, so their relative importance is currently unresolved. Furthermore, potential interactions between the two levels of diversity, which likely occur in natural systems, have not been investigated. To clarify these issues, we conducted three experiments in a freshwater sand dune ecosystem. We (1) independently manipulated plant species diversity, (2) independently manipulated genetic diversity within the dominant plant species, Ammophila breviligulata, and (3) jointly manipulated genetic diversity within the dominant plant and species diversity. We found that genetic diversity within the dominant plant species, Ammophila breviligulata, more strongly influenced arthropod communities than plant species diversity, but this effect was dependent on the presence of other species. In species mixtures, A. breviligulata genetic diversity altered overall arthropod community composition, and arthropod richness and abundance peaked at the highest level of genetic diversity. Positive nonadditive effects of diversity were detected, suggesting that arthropods respond to emergent properties of diverse plant communities. However, in the independent manipulations where A. breviligulata was alone, effects of genetic diversity were weaker, with only arthropod richness responding. In contrast, plant species diversity only influenced arthropods when A. breviligulata was absent, and then only influenced herbivore abundance. In addition to showing that genetic diversity within a dominant plant species can have large effects on arthropod community composition, these results suggest that understanding how species diversity and genetic diversity interact to influence community structure may be critically important for predicting the consequences of biodiversity loss. PMID:23858643

Crawford, Kerri M; Rudgers, Jennifer A

2013-05-01

91

Leaf miner and plant galler species richness on Acacia: relative importance of plant traits and climate.  

PubMed

Diversity patterns of herbivores have been related to climate, host plant traits, host plant distribution and evolutionary relationships individually. However, few studies have assessed the relative contributions of a range of variables to explain these diversity patterns across large geographical and host plant species gradients. Here we assess the relative influence that climate and host plant traits have on endophagous species (leaf miners and plant gallers) diversity across a suite of host species from a genus that is widely distributed and morphologically variable. Forty-six species of Acacia were sampled to encapsulate the diversity of species across four taxonomic sections and a range of habitats along a 950 km climatic gradient: from subtropical forest habitats to semi-arid habitats. Plant traits, climatic variables, leaf miner and plant galler diversity were all quantified on each plant species. In total, 97 leaf mining species and 84 plant galling species were recorded from all host plants. Factors that best explained leaf miner richness across the climatic gradient (using AIC model selection) included specific leaf area (SLA), foliage thickness and mean annual rainfall. The factor that best explained plant galler richness across the climatic gradient was C:N ratio. In terms of the influence of plant and climatic traits on species composition, leaf miner assemblages were best explained by SLA, foliage thickness, mean minimum temperature and mean annual rainfall, whilst plant gall assemblages were explained by C:N ratio, %P, foliage thickness, mean minimum temperature and mean annual rainfall. This work is the first to assess diversity and structure across a broad environmental gradient and a wide range of potential key climatic and plant trait determinants simultaneously. Such methods provide key insights into endophage diversity and provide a solid basis for assessing their responses to a changing climate. PMID:20349248

Bairstow, Katy A; Clarke, Kerri L; McGeoch, Melodie A; Andrew, Nigel R

2010-06-01

92

Phytotoxicity of Designated Pollutants on Plant Species.  

National Technical Information Service (NTIS)

A ground cloud is formed as the space shuttle rocket lifts off. The phytotoxicity of products released from thic cloud was studied. Aluminum oxide dust and droplets of hydrogen chloride (HCl) were found on leaves of plants at the Kennedy Space Center foll...

A. L. Granett

1984-01-01

93

Effect of Designated Pollutants on Plant Species.  

National Technical Information Service (NTIS)

The phytotoxicity of short (20 minute) exposure of HCl and HF gases and of liquid HCl as investigated in a series of studies under controlled greenhouse conditions and in the field. Field plants exposed weekly to gaseous HCl were injured when young but fi...

A. L. Granett O. C. Taylor

1981-01-01

94

Plant species differences in particulate matter accumulation on leaf surfaces.  

PubMed

Particulate matter (PM) accumulation on leaves of 22 trees and 25 shrubs was examined in test fields in Norway and Poland. Leaf PM in different particle size fractions (PM(10), PM(2.5), PM(0.2)) differed among the species, by 10- to 15-folds at both test sites. Pinus mugo and Pinus sylvestris, Taxus media and Taxus baccata, Stephanandra incisa and Betula pendula were efficient species in capturing PM. Less efficient species were Acer platanoides, Prunus avium and Tilia cordata. Differences among species within the same genus were also observed. Important traits for PM accumulation were leaf properties such as hair and wax cover. The ranking presented in terms of capturing PM can be used to select species for air pollution removal in urban areas. Efficient plant species and planting designs that can shield vulnerable areas in urban settings from polluting traffic etc. can be used to decrease human exposure to anthropogenic pollutants. PMID:22554531

Sæbø, A; Popek, R; Nawrot, B; Hanslin, H M; Gawronska, H; Gawronski, S W

2012-06-15

95

Rare and Endangered Vascular Plant Species in New Jersey.  

National Technical Information Service (NTIS)

The report documents the known status of rare, threatened, or endangered vascular plants in the state of New Jersey. The report is based on a thorough review of the literature, herbaria searches and field work for selected species. Approximately 388 speci...

D. B. Snyder V. E. Vivian

1981-01-01

96

Factors determining plant species richness in Alaskan artic tundra  

Microsoft Academic Search

We studied the relationship between plant N:P ratio, soil characteristics and species richness in wet sedge and tussock tundra in northern Alaska at seven sites. We also collected data on soil characteristics, above-ground biomass, species richness and composition. The N:P ratio of the vegetation did not show any relationship with species richness. The N:P ratio of the soil was related

Welle van der M. E. W; Peter J. Vermeulen; Gaius R. Shaver; Frank Berendse

2003-01-01

97

Evaluation of Chlorinated Solvent Removal Efficiency Among Three Wetland Plant Species: A Mesocom Study.  

National Technical Information Service (NTIS)

Different species of plants need to be studied individually to compare the remediation efficiency of each species. This research will study three different wetland plants species and an unplanted control, under a laboratory setting. Each plant has a diffe...

J. Yan

2006-01-01

98

New York State Plant Ranking System for Evaluating Non-Native Plant Species for Invasiveness  

Microsoft Academic Search

PURPOSE: The purpose of the New York Invasive Plant Ranking System is to assess the invasive nature of non-native plant species that are established in NYS, and also to assess the potential invasiveness of species that are new arrivals or are not yet present. This ranking system is designed to be repeatable, based on the best available science, clearly explained

Marilyn J. Jordan; Gerry Moore; Troy W. Weldy

2010-01-01

99

The evolution of species concepts and species recognition criteria in plant pathogenic fungi  

Microsoft Academic Search

In this paper, we review historical and contemporary species concepts and species recognition criteria for plant pathogenic\\u000a fungi. Previous incongruent and unstable classification based on subjective and changing criteria have led to some confusion,\\u000a especially amongst plant pathologists. The goal of systematics is to provide an informative and robust framework that stands\\u000a the test of time. The taxonomic histories of

Lei Cai; Tatiana Giraud; Ning Zhang; Dominik Begerow; Guohong Cai; Roger G. Shivas

100

Cytoprotective and antioxidant effects of the edible halophyte Sarcocornia perennis L. (swampfire) against lead-induced toxicity in renal cells.  

PubMed

Lead (Pb) exposure is considered as a risk factor responsible for renal impairment in humans. On the other hand, the halophyte Sarcocornia perennis is a fresh vegetable crop suitable for leafy vegetable production. This study was designed to evaluate the in vitro protective activity of S. perennis against lead-induced damages in HEK293 kidney cells. Morphological and biochemical indicators were used to assess cytotoxicity and oxidative damages caused by Pb treatment on the cells. Our results showed that lead induced (1) a decrease in cell viability (MTT), (2) cell distortion and cohesion loss, (3) superoxide anion production and lipid peroxidation. Conversely, addition of S. perennis extract to the lead-containing medium alleviated every above syndrome. Thus, cell survival was increased and the production of reactive oxygen species caused by Pb treatment was inhibited. Taken together, our study revealed that S. perennis has potent cytoprotective effect against Pb-induced toxicity in HEK 293 cell. Such action would proceed through the decrease in ROS levels and resulting oxidative stress, which suggests a potential interest of this halophyte in the treatment of oxidative-stress related diseases. PMID:23755863

Gargouri, Manel; Magné, Christian; Dauvergne, Xavier; Ksouri, Riadh; El Feki, Abdelfattah; Metges, Marie-Agnès Giroux; Talarmin, Hélène

2013-09-01

101

No universal scale-dependent impacts of invasive species on native plant species richness.  

PubMed

A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species-area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 (Science 339, 316-318. (doi:10.1126/science.1226817)), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness-log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal. PMID:24478201

Stohlgren, Thomas J; Rejmánek, Marcel

2014-01-01

102

Prediction of plant species distributions across six millennia.  

PubMed

The usefulness of species distribution models (SDMs) in predicting impacts of climate change on biodiversity is difficult to assess because changes in species ranges may take decades or centuries to occur. One alternative way to evaluate the predictive ability of SDMs across time is to compare their predictions with data on past species distributions. We use data on plant distributions, fossil pollen and current and mid-Holocene climate to test the ability of SDMs to predict past climate-change impacts. We find that species showing little change in the estimated position of their realized niche, with resulting good model performance, tend to be dominant competitors for light. Different mechanisms appear to be responsible for among-species differences in model performance. Confidence in predictions of the impacts of climate change could be improved by selecting species with characteristics that suggest little change is expected in the relationships between species occurrence and climate patterns. PMID:18279357

Pearman, Peter B; Randin, Christophe F; Broennimann, Olivier; Vittoz, Pascal; van der Knaap, Willem O; Engler, Robin; Le Lay, Gwenaelle; Zimmermann, Niklaus E; Guisan, Antoine

2008-04-01

103

Herbivore effects on plant species density at varying productivity levels  

USGS Publications Warehouse

Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate herbivory. After three growing seasons, fertilization increased community biomass in all plots, but decreased species density (the number of species per unit area) only in plots protected from herbivory. Herbivory alone did not alter species density at either site. At the brackish marsh, herbivory caused a shift in dominance in the fertilized plots from a species that is considered the competitive dominant, but is selectively eaten, to another less palatable species. At the fresh marsh, increased dead biomass in the absence of herbivory and in the fertilized plots probably contributed to the decrease in species density, perhaps by limiting germination of annuals. Our results support those of other fertilization studies in which plant species density decreases with increased biomass, but only in those plots protected from herbivory.

Gough, L.; Grace, J. B.

1998-01-01

104

Towards a working list of all known plant species.  

PubMed Central

A complete listing of the world's known plant species has long been considered desirable but has remained an elusive target for generations of botanists. The adoption of the Global Strategy for Plant Conservation has reinforced the urgent need for a global plant checklist to support, facilitate and monitor the conservation and sustainable use of plant diversity worldwide. The increasing availability of large databases of biological information over the Internet has demonstrated that many of the obstacles to the collation and dissemination of vast, shared datasets can be overcome. We examine the challenges that still remain to be addressed if the botanical community is to achieve its ambitious objective of delivering a working list of all known plant species by 2010.

Lughadha, Eimear Nic

2004-01-01

105

Plant regeneration from cultured leaf explants of eight wild tomato species and two related Solanum species  

Microsoft Academic Search

Summary  Optimum conditions for plant regeneration from cultured leaf explants were ascertained for eight different wild tomato (Lycopersicon) species and two closely relatedSolanum species. Of the eight media tested, basal MS medium supplemented with 5 µM of the cytokinin 6-benzyladenine proved to be the best overall regeneration medium. Regeneration frequency varied significantly\\u000a between species with maximum frequency of regeneration observed forL.

S. A. Kut; D. A. Evans

1982-01-01

106

Floristic summary of plant species in the air pollution literature  

USGS Publications Warehouse

A floristic summary and analysis was performed on a list of the plant species that have been studied for the effects of gaseous and chemical air pollutants on vegetation in order to compare the species with the flora of North America north of Mexico. The scientific names of 2081 vascular plant species were extracted from almost 4000 journal articles stored in two large literature databases on the effects of air pollutants on plants. Three quarters of the plant species studied occur in North America, but this was only 7% of the total North American flora. Sixteen percent and 56% of all North American genera and families have been studied. The most studied genus is Pinus with 70% of the North American species studied, and the most studied family is the grass family, with 12% of the species studied. Although Pinus is ranked 86th in the North American flora, the grass family is ranked third, indicating that representation at the family level is better than at the genus level. All of the top ten families in North America are represented in the top 20 families in the air pollution effects literature, but only one genus (Lupinus) in the top ten genera in North America is represented in the top thirteen genera in the air pollution literature.

Bennett, J. P.

1996-01-01

107

Plant species richness regulates soil respiration through changes in productivity  

PubMed Central

Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1569-5) contains supplementary material, which is available to authorized users.

van Ruijven, Jasper; Berendse, Frank

2010-01-01

108

Effects of plant host species and plant community richness on streptomycete community structure.  

PubMed

We investigated soil streptomycete communities associated with four host plant species (two warm season C4 grasses: Andropogon gerardii, Schizachyrium scoparium and two legumes: Lespedeza capitata, Lupinus perennis), grown in plant communities varying in species richness. We used actinobacteria-selective PCR coupled with pyrosequencing to characterize streptomycete community composition and structure. The greatest pairwise distances between communities were observed in contrasts between monocultures of different plant species, indicating that plant species exert distinct selective effects on soil streptomycete populations. Increasing plant richness altered the composition and structure of streptomycete communities associated with each host plant species. Significant relationships between plant community characteristics, soil edaphic characteristics, and streptomycete community structure suggest that host plant effects on soil microbial communities may be mediated through changes to the soil environment. Co-occurring streptomycete taxa also shared consistent relationships with soil edaphic properties, providing further indication of the importance of habitat preference for taxon occurrence. Physical distance between sampling points had a significant influence on streptomycete community similarity. This work provides a detailed characterization of soil streptomycete populations across a field scale and in relation to plant host identity and plant community richness. PMID:23013423

Bakker, Matthew G; Bradeen, James M; Kinkel, Linda L

2013-03-01

109

Which ornamental plant species effectively remove benzene from indoor air?  

NASA Astrophysics Data System (ADS)

Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.

Liu, Yan-Ju; Mu, Yu-Jing; Zhu, Yong-Guan; Ding, Hui; Crystal Arens, Nan

110

Aminomethylphosphonic acid accumulation in plant species treated with glyphosate.  

PubMed

Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels. PMID:18298069

Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Nandula, Vijay K

2008-03-26

111

Regeneration niche differentiates functional strategies of desert woody plant species  

PubMed Central

Plant communities vary dramatically in the number and relative abundance of species that exhibit facilitative interactions, which contributes substantially to variation in community structure and dynamics. Predicting species’ responses to neighbors based on readily measurable functional traits would provide important insight into the factors that structure plant communities. We measured a suite of functional traits on seedlings of 20 species and mature plants of 54 species of shrubs from three arid biogeographic regions. We hypothesized that species with different regeneration niches—those that require nurse plants for establishment (beneficiaries) versus those that do not (colonizers)—are functionally different. Indeed, seedlings of beneficiary species had lower relative growth rates, larger seeds and final biomass, allocated biomass toward roots and height at a cost to leaf mass fraction, and constructed costly, dense leaf and root tissues relative to colonizers. Likewise at maturity, beneficiaries had larger overall size and denser leaves coupled with greater water use efficiency than colonizers. In contrast to current hypotheses that suggest beneficiaries are less “stress-tolerant” than colonizers, beneficiaries exhibited conservative functional strategies suited to persistently dry, low light conditions beneath canopies, whereas colonizers exhibited opportunistic strategies that may be advantageous in fluctuating, open microenvironments. In addition, the signature of the regeneration niche at maturity indicates that facilitation expands the range of functional diversity within plant communities at all ontogenetic stages. This study demonstrates the utility of specific functional traits for predicting species’ regeneration niches in hot deserts, and provides a framework for studying facilitation in other severe environments. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1741-y) contains supplementary material, which is available to authorized users.

Briggs, John M.

2010-01-01

112

Acclimation of plant species to elevated CO{sub 2}  

SciTech Connect

Plant species differ in assimilated carbon partitioning between starch, sucrose and hexose sugars. Soluble sugars have been implicated to play a role in downregulating rubisco and other photosynthesis enzymes on the level of transcription. In this study we compared high CO{sub 2} response of plants with different physiology. Cucumber, tobacco and sunflower were chosen as relatively good starch accumulators, spinach and sugar-beet as species with high leaf soluble sugar levels. In addition woody species cottonwood and salt cedar and one C{sub 4} species (corn) were studied. Plants were grown from seed at three CO{sub 2} levels: 330 {mu}bar, 660 {mu}bar and 1500 {mu}bar. Two soil nitrogen levels were used: one that allowed normal growth and the other that caused about 5 times growth suppression. All species except corn (C{sub 4}) showed downregulation of leaf rubisco activity. This downregulation was due to decrease of rubisco content, activation state remaining unchanged. Initial slope of AC{sub i} curve and rubisco activity were in good correlation. Low and high nitrogen plants had similar relative changes in photosynthetic activity. Final harvest onground weight correlated with CO{sub 2} uptake at growth conditions. We concluded that soluble sugars per se do not cause downregulation of leaf photosynthetic activity at high CO{sub 2}.

Olavi, K.; Ball, J.T. [Desert Research Institute, Reno, NV (United States); Seemann, J. [Univ. of Nevada, Reno, NV (United States)

1995-06-01

113

Leaf miner and plant galler species richness on Acacia : relative importance of plant traits and climate  

Microsoft Academic Search

Diversity patterns of herbivores have been related to climate, host plant traits, host plant distribution and evolutionary\\u000a relationships individually. However, few studies have assessed the relative contributions of a range of variables to explain\\u000a these diversity patterns across large geographical and host plant species gradients. Here we assess the relative influence\\u000a that climate and host plant traits have on endophagous

Katy A. Bairstow; Kerri L. Clarke; Melodie A. McGeoch; Nigel R. Andrew

2010-01-01

114

Efficient distinction of invasive aquatic plant species from non-invasive related species using DNA barcoding.  

PubMed

Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnH-psbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH-psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics. PMID:23039943

Ghahramanzadeh, R; Esselink, G; Kodde, L P; Duistermaat, H; van Valkenburg, J L C H; Marashi, S H; Smulders, M J M; van de Wiel, C C M

2013-01-01

115

Metal species involved in long distance metal transport in plants  

PubMed Central

The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids.

Alvarez-Fernandez, Ana; Diaz-Benito, Pablo; Abadia, Anunciacion; Lopez-Millan, Ana-Flor; Abadia, Javier

2014-01-01

116

Metal species involved in long distance metal transport in plants.  

PubMed

The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

Alvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

2014-01-01

117

Taxonomic perspective of plant species yielding vegetable oils used in cosmetics and skin care products  

Microsoft Academic Search

A search conducted to determine the plants yielding vegetable oils resulted in 78 plant species with potential use in cosmetics and skin care products. The taxonomic position of these plant species is described with a description of vegetable oils from these plants and their use in cosmetics and skin care products. These species belonged to 74 genera and 45 plant

Mohammad Athar; Syed Mahmood Nasir

118

AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES  

EPA Science Inventory

Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

119

ORGANIC PESTICIDE MODIFICATION OF SPECIES INTERACTIONS USING ANNUAL PLANT COMMUNITIES  

EPA Science Inventory

A method is proposed and tested for assessing multispecies responses to three pesticides (atrazine, 2,4,D and malathion). Pesticides were applied at two concentrations, mon model plant communities grown in raised beds using soil containing a natural weed bank. over by species was...

120

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2013 CFR

...species of native mammals, birds, and plants. 670.25 Section 670.25 Public... CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation of...

2013-10-01

121

Biosynthesis of Jasmonic Acid by Several Plant Species 1  

PubMed Central

Six plant species metabolized 18O-labeled 12-oxo-cis,cis-10,15-phytodienoic acid (12-oxo-PDA) to short chain cyclic fatty acids. The plant species were corn (Zea mays L.), eggplant (Solanum melongena L.), flax (Linum usitatissimum L.), oat (Avena sativa L.), sunflower (Helianthus annuus L.), and wheat (Triticum aestivum L.). Among the products was jasmonic acid, a natural plant constituent with growth-regulating properties. The pathway is the same as the one recently reported by us for jasmonic acid synthesis in Vicia faba L. pericarp. First, the ring double bond of 12-oxo-PDA is saturated; then ?-oxidation enzymes remove six carbons from the carboxyl side chain of the ring. Substrate specificity studies indicated that neither the stereochemistry of the side chain at carbon 13 of 12-oxo-PDA nor the presence of the double bond at carbon 15 was crucial for either enzyme step. The presence of enzymes which convert 12-oxo-PDA to jasmonic acid in several plant species indicates that this may be a general metabolic pathway in plants.

Vick, Brady A.; Zimmerman, Don C.

1984-01-01

122

Plant species richness and ecosystem multifunctionality in global drylands  

PubMed Central

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report on the first global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality, and always included species richness as a predictor variable. Our results suggest that preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adria; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutierrez, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

2013-01-01

123

Tocopherol content and isomers' composition in selected plant species.  

PubMed

We have analyzed leaves of several plant species for the content and isomers' composition of tocopherols and it was found that their content was considerably higher in some cases than previously reported, especially in autumn tree leaves where the average tocopherols' level was in the range of 300-640 microg/g fresh weight and accounted for 40-140% of the chlorophyll amount. The isomers' composition, usually dominated by alpha-tocopherol in leaves, was different in some plant species with a high percentage of gamma-tocopherol (Kalanchoe, lettuce, dodder species, and young maple leaves) or delta-tocopherol (Cuscuta epithymum and Cuscuta japonica). C. japonica was exceptional by the complete absence of alpha-tocopherol. The possible reasons and physiological significance of these observations have been discussed. PMID:18023194

Szyma?ska, Renata; Kruk, Jerzy

2008-01-01

124

Plant species richness and ecosystem multifunctionality in global drylands.  

PubMed

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands. PMID:22246775

Maestre, Fernando T; Quero, José L; Gotelli, Nicholas J; Escudero, Adrián; Ochoa, Victoria; Delgado-Baquerizo, Manuel; García-Gómez, Miguel; Bowker, Matthew A; Soliveres, Santiago; Escolar, Cristina; García-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceição, Abel A; Cabrera, Omar; Chaieb, Mohamed; Derak, McHich; Eldridge, David J; Espinosa, Carlos I; Florentino, Adriana; Gaitán, Juan; Gatica, M Gabriel; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R; Hernández, Rosa M; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Aníbal; Pucheta, Eduardo; Ramírez-Collantes, David A; Romão, Roberto; Tighe, Matthew; Torres-Díaz, Cristian; Val, James; Veiga, José P; Wang, Deli; Zaady, Eli

2012-01-13

125

Horizontal transfer of chloroplast genomes between plant species  

PubMed Central

The genomes of DNA-containing cell organelles (mitochondria, chloroplasts) can be laterally transmitted between organisms, a process known as organelle capture. Organelle capture often occurs in the absence of detectable nuclear introgression, and the capture mechanism is unknown. Here, we have considered horizontal genome transfer across natural grafts as a mechanism underlying chloroplast capture in plants. By grafting sexually incompatible species, we show that complete chloroplast genomes can travel across the graft junction from one species into another. We demonstrate that, consistent with reported phylogenetic evidence, replacement of the resident plastid genome by the alien genome occurs in the absence of intergenomic recombination. Our results provide a plausible mechanism for organelle capture in plants and suggest natural grafting as a path for horizontal gene and genome transfer between sexually incompatible species.

Stegemann, Sandra; Keuthe, Mandy; Greiner, Stephan; Bock, Ralph

2012-01-01

126

Accumulation of K+ and Cs+ in Tropical Plant Species  

NASA Astrophysics Data System (ADS)

Concentrations of K+ and 137Cs+ in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K+,Cs+ ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that 137Cs+ is positively correlated to 40K+ concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of 40K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the 40K experimental results in the fruit ripening processes of lemon trees.

Velasco, H.; Anjos, R. M.; Zamboni, C. B.; Macario, K. D.; Rizzotto, M.; Cid, A. S.; Medeiros, I. M. A.; Fernández, J.; Rubio, L.; Audicio, P.; Lacerda, T.

2010-08-01

127

Rising from the sea: correlations between sulfated polysaccharides and salinity in plants.  

PubMed

High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops. PMID:21552557

Aquino, Rafael S; Grativol, Clicia; Mourão, Paulo A S

2011-01-01

128

Rising from the Sea: Correlations between Sulfated Polysaccharides and Salinity in Plants  

PubMed Central

High salinity soils inhibit crop production worldwide and represent a serious agricultural problem. To meet our ever-increasing demand for food, it is essential to understand and engineer salt-resistant crops. In this study, we evaluated the occurrence and function of sulfated polysaccharides in plants. Although ubiquitously present in marine algae, the presence of sulfated polysaccharides among the species tested was restricted to halophytes, suggesting a possible correlation with salt stress or resistance. To test this hypothesis, sulfated polysaccharides from plants artificially and naturally exposed to different salinities were analyzed. Our results revealed that the sulfated polysaccharide concentration, as well as the degree to which these compounds were sulfated in halophytic species, were positively correlated with salinity. We found that sulfated polysaccharides produced by Ruppia maritima Loisel disappeared when the plant was cultivated in the absence of salt. However, subjecting the glycophyte Oryza sativa Linnaeus to salt stress did not induce the biosynthesis of sulfated polysaccharides but increased the concentration of the carboxylated polysaccharides; this finding suggests that negatively charged cell wall polysaccharides might play a role in coping with salt stress. These data suggest that the presence of sulfated polysaccharides in plants is an adaptation to high salt environments, which may have been conserved during plant evolution from marine green algae. Our results address a practical biological concept; additionally, we suggest future strategies that may be beneficial when engineering salt-resistant crops.

Aquino, Rafael S.; Grativol, Clicia; Mourao, Paulo A. S.

2011-01-01

129

Light dependency of VOC emissions from selected Mediterranean plant species  

NASA Astrophysics Data System (ADS)

The light, temperature and stomatal conductance dependencies of volatile organic compound (VOC) emissions from ten plant species commonly found in the Mediterranean region were studied using a fully controlled leaf cuvette in the laboratory. At standard conditions of temperature and light (30°C and 1000 ?mol m -2 s -1 PAR), low emitting species ( Arbutus unedo, Pinus halepensis, Cistus incanus, Cistus salvifolius, Rosmarinus officinalis and Thymus vulgaris) emitted between 0.1 and 5.0 ?g (C) (total VOCs) g -1 dw h -1, a medium emitter ( Pinus pinea) emitted between 5 and 10 ?g (C) g -1 dw h -1 and high emitters ( Cistus monspeliensis, Lavendula stoechas and Quercus sp.) emitted more than 10 ?g (C) g -1 dw h -1. VOC emissions from all of the plant species investigated showed some degree of light dependency, which was distinguishable from temperature dependency. Emissions of all compounds from Quercus sp. were light dependent. Ocimene was one of several monoterpene compounds emitted by P. pinea and was strongly correlated to light. Only a fraction of monoterpene emissions from C. incanus exhibited apparent weak light dependency but emissions from this plant species were strongly correlated to temperature. Data presented here are consistent with past studies, which show that emissions are independent of stomatal conductance. These results may allow more accurate predictions of monoterpene emission fluxes from the Mediterranean region to be made.

Owen, S. M.; Harley, P.; Guenther, A.; Hewitt, C. N.

130

Plant species richness increases phosphatase activities in an experimental grassland  

NASA Astrophysics Data System (ADS)

Plant species richness has been shown to increase aboveground nutrient uptake requiring the mobilization of soil nutrient pools. For phosphorus (P) the underlying mechanisms for increased P release in soil under highly diverse grassland mixtures remain obscure because aboveground P storage and concentrations of inorganic and organic P in soil solution and differently reactive soil P pools are unrelated (Oelmann et al. 2011). The need of plants and soil microorganisms for P can increase the exudation of enzymes hydrolyzing organically bound P (phosphatases) which might represent an important release mechanism of inorganic P in a competitive environment such as highly diverse grassland mixtures. Our objectives were to test the effects of i) plant functional groups (legumes, grasses, non-leguminous tall and small herbs), and of (ii) plant species richness on microbial P (Pmic) and phosphatase activities in soil. In autumn 2013, we measured Pmic and alkaline phosphomonoesterase and phosphodiesterase activities in soil of 80 grassland mixtures comprising different community compositions and species richness (1, 2, 4, 8, 16, 60) in the Jena Experiment. In general, Pmic and enzyme activities were correlated (r = 0.59 and 0.46 for phosphomonoesterase and phosphodiesterase activities, respectively; p

Hacker, Nina; Wilcke, Wolfgang; Oelmann, Yvonne

2014-05-01

131

Corridors Increase Plant Species Richness at Large Scales  

SciTech Connect

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.; Tewksbury, Joshua J.; Levey, Douglas J.

2006-09-01

132

Antimicrobial potential of some plant extracts against Candida species.  

PubMed

The increase in the resistance to antimicrobial drugs in use has attracted the attention of the scientific community, and medicinal plants have been extensively studied as alternative agents for the prevention of infections. The Candida genus yeast can become an opportunistic pathogen causing disease in immunosuppressive hosts. The purpose of this study was to evaluate dichloromethane and methanol extracts from Mentha piperita, Rosmarinus officinalis, Arrabidaea chica, Tabebuia avellanedae, Punica granatum and Syzygium cumini against Candida species through the analysis of Minimum Inhibitory Concentration (MIC). Results presented activity of these extracts against Candida species, especially the methanol extract. PMID:21180915

Höfling, J F; Anibal, P C; Obando-Pereda, G A; Peixoto, I A T; Furletti, V F; Foglio, M A; Gonçalves, R B

2010-11-01

133

The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na+ loading in xylem and confers salt tolerance in transgenic tobacco  

PubMed Central

Background Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1) gene encodes a plasma membrane Na+/H+ antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. Results The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC), chlorophyll, K+/Na+ ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT) plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS) and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na+ content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na+ content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na+ loading to xylem from root and leaf tissues. Transgenic lines also showed increased K+ and Ca2+ content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Conclusions Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na+ efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na+ content in different organs and also affect the other transporters activity indirectly. These results broaden the role of SbSOS1 in planta and suggest that this gene could be used to develop salt-tolerant transgenic crops.

2012-01-01

134

Status of endangered and threatened plant species on Nevada Test Site: a survey. Part 1. Endangered species  

Microsoft Academic Search

Eight plant species which occur on NTS and one which occurs just outside the west boundary have been suggested by the Fish and Wildlife Service (FWS) as endangered plants in Nevada under the Endangered Species Act of 1973. This survey provides a basis for suggesting that seven of the nine species remain as candidates for the endangered status, and that

W. A. Rhoads; M. P. Williams

1977-01-01

135

Introduction to the Invasive Plant Species and the New Bioeconomy Symposium  

Microsoft Academic Search

The rapid expansion of the plant bioeconomy is creating strong economic incentives to distribute novel plant material, including transgenic cultivars, exotic species, and species that were formerly constrained to small geographical areas, at large geographical scales. Such introductions carry with them the risk of invasive spread of the introduced species (Simberloff and Alexander 1998). Deployment of plant species for biofuel

Adam S. Davis; Daniel C. Brainard; Eric R. Gallandt

2008-01-01

136

Different Arbuscular Mycorrhizal Fungal Species Are Potential Determinants of Plant Community Structure  

Microsoft Academic Search

Almost all natural plant communities contain arbuscular mycorrhizal fungi (AMF). We hypothesized that the species composition of AMF communities could have the potential to determine plant community structure if the growth response to different AMF species or to communities of AMF species varies among plant species. To test the existence of such a differential response we conducted a pot experiment

Thomas Boller; Andres Wiemken; Ian R. Sanders

1998-01-01

137

New evidence for electrotropism in some plant species  

NASA Astrophysics Data System (ADS)

The ever-present global Atmospheric Electrical F ield (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity to electrotropic effect in different electric field intensities and directions. It was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions in plant tissues. We use a "reference field" (130 V/m) and stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed field polarity. In conclusion electrotropic pl nts deprived of the electrical field do not develop asa expected, as can be seen in BIOSPHERE 2. It was a sad example of what happens when one forgets to provide the plants with this vital natural environmental factor. Electrical fields of different intensity and direction are cheap and easy to generate. More plants were investigated in order to verify their response to electrical fields. Effect of several kV/m horizontal fields, was compared with the vertical 130 V/m field (ued as a reference) and it was shown that electrotropic sensitivity can be found easily. Surprisingly even the nonelectrotropic plants, whose initial growth rate does not depend on the field strength, when they develop leaves begin to lean towards the positive electrode, and become elect rotropic. Ground based fitotron experiments enable us to select cheaply plants which shall be suitable for food production in space using electical fields to restore to plants the sense of direction of growth.

Gorgolewski, S.; Rozej, B.

138

Hybrid Viability and Fertility in Co-occuring Plant Species  

NASA Astrophysics Data System (ADS)

Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

Hernandez, E.; Garcia, C.; Yost, J.

2012-12-01

139

Does phosphorus limitation promote species-rich plant communities?  

Microsoft Academic Search

It is known that the number of limiting nutrients may affect the species richness of plant communities, but it is unclear\\u000a whether the type of nutrient limitation is also important. I place the results from a study in Patagonia (elsewhere in this\\u000a issue) in the context of the number and types of nutrients that are limiting. I present four mechanisms

Harry Olde Venterink

140

Reactive Oxygen Species, Oxidative Stress and Plant Ion Channels  

Microsoft Academic Search

\\u000a Reactive oxygen species (ROS) are important toxic and regulatory agents in plants. They are produced in response to a number\\u000a of stimuli, including major biotic and abiotic stresses. Disruption of respiratory and photosynthetic electron transport chains,\\u000a as well as activation of NADPH oxidases (NOXs) and peroxidases, is a major reason for ROS generation and accumulation during\\u000a stress conditions. ROS production

Vadim Demidchik

141

Nuclear DNA content of some important plant species  

Microsoft Academic Search

Nuclear DNA contents of more than 100 important plant species were measured by flow cytometry of isolated nuclei stained with\\u000a propidium iodide.Arabidopsis exhibits developmentally regulated multiploidy and has a 2C nuclear DNA content of 0.30 pg (145 Mbp\\/1C), twice the value\\u000a usually cited. The 2C value for rice is only about three times that ofArabidopsis. Tomato has a 2C value

K. Arumuganathan; E. D. Earle

1991-01-01

142

Diversity of plant species in arecanut agroforests of south Meghalaya, north-east India  

Microsoft Academic Search

In south Meghalaya, farmers maintain a variety of economically important plant species in arecanut agroforestry systems. We\\u000a investigated plant species composition of arecanut agroforests of south Meghalaya and encountered 160 plants, which included\\u000a 83 tree species, 22 shrub species, 41 herb species and 14 climber species. The study reveals that arecanut agroforests provide\\u000a cash income, medicine, timber, fuelwood and edibles

H. Tynsong; B. K. Tiwari

2010-01-01

143

Consequences of plant invasions on compartmentalization and species' roles in plant-pollinator networks.  

PubMed

Compartmentalization-the organization of ecological interaction networks into subsets of species that do not interact with other subsets (true compartments) or interact more frequently among themselves than with other species (modules)-has been identified as a key property for the functioning, stability and evolution of ecological communities. Invasions by entomophilous invasive plants may profoundly alter the way interaction networks are compartmentalized. We analysed a comprehensive dataset of 40 paired plant-pollinator networks (invaded versus uninvaded) to test this hypothesis. We show that invasive plants have higher generalization levels with respect to their pollinators than natives. The consequences for network topology are that-rather than displacing native species from the network-plant invaders attracting pollinators into invaded modules tend to play new important topological roles (i.e. network hubs, module hubs and connectors) and cause role shifts in native species, creating larger modules that are more connected among each other. While the number of true compartments was lower in invaded compared with uninvaded networks, the effect of invasion on modularity was contingent on the study system. Interestingly, the generalization level of the invasive plants partially explains this pattern, with more generalized invaders contributing to a lower modularity. Our findings indicate that the altered interaction structure of invaded networks makes them more robust against simulated random secondary species extinctions, but more vulnerable when the typically highly connected invasive plants go extinct first. The consequences and pathways by which biological invasions alter the interaction structure of plant-pollinator communities highlighted in this study may have important dynamical and functional implications, for example, by influencing multi-species reciprocal selection regimes and coevolutionary processes. PMID:24943368

Albrecht, Matthias; Padrón, Benigno; Bartomeus, Ignasi; Traveset, Anna

2014-08-01

144

Invasive Plant Species: Inventory, Mapping, and Monitoring - A National Strategy  

USGS Publications Warehouse

America is under siege by invasive species of plants and animals, and by diseases. The current environmental, economic, and health-related costs of invasive species could exceed $138 billion per year-more than all other natural disasters combined. Notorious examples include West Nile virus, Dutch elm disease, chestnut blight, and purple loose- strife in the Northeast; kudzu, Brazilian peppertree, water hyacinth, nutria, and fire ants in the Southeast; zebra mussels, leafy spurge, and Asian long-horn beetles in the Midwest; salt cedar, Russian olive, and Africanized bees in the Southwest; yellow star thistle, European wild oats, oak wilt disease, Asian clams, and white pine blister rust in California; cheatgrass, various knapweeds, and thistles in the Great Basin; whirling disease of salmonids in the Northwest; hundreds of invasive species from microbes to mammals in Hawaii; and the brown tree snake in Guam. Thousands of species from other countries are introduced intentionally or accidentally into the United States each year. Based on past experience, 10-15 percent can be expected to establish free-living populations and about 1 percent can be expected to cause significant impacts to ecosystems, native species, economic productivity, and (or) human health.

Ludke, J. Larry; D'Erchia, Frank; Coffelt, Jan; Hanson, Leanne

2002-01-01

145

[Psychoactive plant species--actual list of plants prohibited in Poland].  

PubMed

According to the Act on Counteracting Drug Addiction (20-th of March, 2009, Dz. U. Nr 63 poz. 520.) the list of federally prohibited plants in Poland was expanded to include 16 new species. Until that time the only illegal plant materials were cannabis, papaver, coca and most of their products. The actual list of herbal narcotics includes species which significantly influence on the central nervous system work but which are rarely described in the national literature. The plants usually come from distant places, where--among primeval cultures--are used for ritual purposes. In our civilization the plants are usually used experimentally, recreationally or to gain particular narcotic effects. The results of the consumption vary: they can be specific or less typical, imitate other substances intake, mental disorders or different pathological states. The plant active substances can interact with other medicaments, be toxic to internal organs, cause serious threat to health or even death. This article describes the sixteen plant species, which are now prohibited in Poland, their biochemical ingredients and their influence on the human organism. PMID:23885543

Simonienko, Katarzyna; Waszkiewicz, Napoleon; Szulc, Agata

2013-01-01

146

Hydroperiod regime controls the organization of plant species in wetlands  

PubMed Central

With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield such signatures are unknown. Focusing on Everglades National Park (ENP) in Florida, we show here that cluster sizes of each species follow a power law probability distribution and that such clusters have well-defined fractal characteristics. Moreover, we individuate and model those signatures via the interplay between global forcings arising from the hydroperiod regime and local controls exerted by neighboring vegetation. With power law clustering often associated with systems near critical transitions, our findings are highly relevant for the management of wetland ecosystems. In addition, our results show that changes in climate and land management have a quantifiable predictable impact on the type of vegetation and its spatial organization in wetlands.

Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

2012-01-01

147

Hydroperiod regime controls the organization of plant species in wetlands.  

PubMed

With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield such signatures are unknown. Focusing on Everglades National Park (ENP) in Florida, we show here that cluster sizes of each species follow a power law probability distribution and that such clusters have well-defined fractal characteristics. Moreover, we individuate and model those signatures via the interplay between global forcings arising from the hydroperiod regime and local controls exerted by neighboring vegetation. With power law clustering often associated with systems near critical transitions, our findings are highly relevant for the management of wetland ecosystems. In addition, our results show that changes in climate and land management have a quantifiable predictable impact on the type of vegetation and its spatial organization in wetlands. PMID:23150589

Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

2012-11-27

148

Stochastic Species Turnover and Stable Coexistence in a Species-Rich, Fire-Prone Plant Community  

PubMed Central

Understanding the mechanisms that maintain diversity is important for managing ecosystems for species persistence. Here we used a long-term data set to understand mechanisms of coexistence at the local and regional scales in the Cape Floristic Region, a global hotspot of plant diversity. We used a dataset comprising 81 monitoring sites, sampled in 1966 and again in 1996, and containing 422 species for which growth form, regeneration mode, dispersal distance and abundances at both the local (site) and meta-community scales are known. We found that species presence and abundance were stable at the meta-community scale over the 30 year period but highly unstable at the local scale, and were not influenced by species' biological attributes. Moreover, rare species were no more likely to go extinct at the local scale than common species, and that alpha diversity in local communities was strongly influenced by habitat. We conclude that stochastic environmental fluctuations associated with recurrent fire buffer populations from extinction, thereby ensuring stable coexistence at the meta-community scale by creating a “neutral-like” pattern maintained by niche-differentiation.

Thuiller, Wilfried; Slingsby, Jasper A.; Privett, Sean D. J.; Cowling, Richard M.

2007-01-01

149

Species-area relationships in Mediterranean-climate plant communities  

USGS Publications Warehouse

Aim: To determine the best-fit model of species-area relationships for Mediterranean-type plant communities and evaluate how community structure affects these species-area models. Location: Data were collected from California shrublands and woodlands and compared with literature reports for other Mediterranean-climate regions. Methods: The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to the power model or exponential model was determined by comparing adjusted r2 values from the least squares regression, pattern of residuals, homoscedasticity across scales, and semi-log slopes at 1-100 m2 and 100-1000 m2. Dominance-diversity curves were tested for fit to the lognormal model, MacArthur's broken stick model, and the geometric and harmonic series. Results: Early successional Western Australia and California shrublands represented the extremes and provide an interesting contrast as the exponential model was the best fit for the former, and the power model for the latter, despite similar total species richness. We hypothesize that structural differences in these communities account for the different species-area curves and are tied to patterns of dominance, equitability and life form distribution. Dominance-diversity relationships for Western Australian heathlands exhibited a close fit to MacArthur's broken stick model, indicating more equitable distribution of species. In contrast, Californian shrublands, both postfire and mature stands, were best fit by the geometric model indicating strong dominance and many minor subordinate species. These regions differ in life form distribution, with annuals being a major component of diversity in early successional Californian shrublands although they are largely lacking in mature stands. Both young and old Australian heathlands are dominated by perennials, and annuals are largely absent. Inherent in all of these ecosystems is cyclical disequilibrium caused by periodic fires. The potential for community reassembly is greater in Californian shrublands where only a quarter of the flora resprout, whereas three quarters resprout in Australian heathlands. Other Californian vegetation types sampled include coniferous forests, oak savannas and desert scrub, and demonstrate that different community structures may lead to a similar species-area relationship. Dominance-diversity relationships for coniferous forests closely follow a geometric model whereas associated oak savannas show a close fit to the lognormal model. However, for both communities, species-area curves fit a power model. The primary driver appears to be the presence of annuals. Desert scrub communities illustrate dramatic changes in both species diversity and dominance-diversity relationships in high and low rainfall years, because of the disappearance of annuals in drought years. Main conclusions: Species-area curves for immature shrublands in California and the majority of Mediterranean plant communities fit a power function model. Exceptions that fit the exponential model are not because of sampling error or scaling effects, rather structural differences in these communities provide plausible explanations. The exponential species-area model may arise in more than one way. In the highly diverse Australian heathlands it results from a rapid increase in species richness at small scales. In mature California shrublands it results from very depauperate richness at the community scale. In both instances the exponential model is tied to a preponderance of perennials and paucity of annuals. For communities fit by a power model, coefficients z and log c exhibit a number of significant correlations with other diversity parameters, suggesting that they have some predictive value in ecological communities.

Keeley, J. E.; Fotheringham, C. J.

2003-01-01

150

Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands  

Microsoft Academic Search

Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receivingprimary treated wastewater. The experimental design includedtwo wetland gravel depths (45 and 60 cm) and five plantingtreatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth × planting

Jerry Coleman; Keith Hench; Keith Garbutt; Alan Sexstone; Gary Bissonnette; Jeff Skousen

2001-01-01

151

Plant-associated bacterial populations on native and invasive plant species: comparisons between 2 freshwater environments.  

PubMed

Plant-microbial interactions have been well studied because of the ecological importance of such relationships in aquatic systems. However, general knowledge regarding the composition of these biofilm communities is still evolving, partly as a result of several confounding factors that are attributable to plant host properties and to hydrodynamic conditions in aquatic environments. In this study, the occurrences of various bacterial phylogenetic taxa on 2 native plants, i.e., mayapple (Podophyllum peltatum L.) and cow parsnip (Heracleum maximum Bartram), and on an invasive species, i.e., garlic mustard (Alliaria petiolata (M. Bieb.) Cavara & Grande), were quantitatively examined using nucleic acid staining and fluorescence in situ hybridization. The plants were incubated in triplicates for about a week within the Kalamazoo River and Pierce Cedar Creek as well as in microcosms. The bacterial groups targeted for enumeration are known to globally occur in relatively high abundance and are also ubiquitously distributed in freshwater environments. Fluorescence in situ hybridization analyses of the bacterioplankton assemblages revealed that the majority of bacterial cells that hybridized with the different probes were similar between the 2 sites. In contrast, the plant-associated populations while similar on the 3 plants incubated in Kalamazoo River, their representations were highest on the 2 native plants relative to the invasive species in Pierce Cedar Creek. Overall, our results further suggested that epiphytic bacterial assemblages are probably under the influences of and probably subsequently respond to multiple variables and conditions in aquatic milieus. PMID:22625420

Olapade, Ola A; Pung, Kayleigh

2012-06-01

152

[Application of ISSR molecular marker in invasive plant species study].  

PubMed

Alien species invasion is one of the most important drivers of worldwide environmental change, which may result in environmental degradation, biodiversity loss, and food and water shortage. It may also increase the possibility and severity of natural disasters, and damage international trade and benefits. In last two decades, DNA-based molecular markers were widely used to detect the genetic diversity of invaded alien species. Inter-simple sequence repeat (ISSR) is a microsatellite-based technique, with the superiorities of simple, quick, reliable, and generating higher levels of DNA polymorphism, and being used as a new molecular marker for genetic study. This paper introduced the principles, characteristics and procedures of ISSR, and summarized its applications in studying the genetic structure, genetic diversity, origin, distribution mode, phylogenesis, and breeding features of invasive plants. PMID:17615894

Gui, Fu-Rong; Guo, Jian-Ying; Wan, Fang-Hao

2007-04-01

153

Reactive oxygen species generation and signaling in plants  

PubMed Central

The introduction of molecular oxygen into the atmosphere was accompanied by the generation of reactive oxygen species (ROS) as side products of many biochemical reactions. ROS are permanently generated in plastids, peroxisomes, mitochiondria, the cytosol and the apoplast. Imbalance between ROS generation and safe detoxification generates oxidative stress and the accumulating ROS are harmful for the plants. On the other hand, specific ROS function as signaling molecules and activate signal transduction processes in response to various stresses. Here, we summarize the generation of ROS in the different cellular compartments and the signaling processes which are induced by ROS.

Tripathy, Baishnab Charan; Oelmuller, Ralf

2012-01-01

154

A Hydroponic Study of Heavy Metal Uptake by Selected Marsh Plant Species.  

National Technical Information Service (NTIS)

Eight marsh plants were grown in chemically controlled hydroponic solutions containing three concentrations of heavy metals to evluate the ability of each plant species to take up and accumulate heavy metals. The marsh plants studies were Cyperus esculent...

C. R. Lee T. C. Sturgis M. C. Landin

1976-01-01

155

Microbial biomass reflects a nitrogen and phosphorous economy of halophytes grown in salty desert soil  

Microsoft Academic Search

Seasonal variations in soil salinity were recorded under the canopy of two halophyte shrubs typical of the hot, dry Negev desert, Zygophyllum dumosum and Reaumuria negevensis. The effects of the fluctuating soil salinity levels on total soluble N and on microbial biomass N and P were also monitored. The microhabitat of the shrubs showed differences in trend and magnitude of

Shlomo Sarig; Andreas Fliessbach; Yosef Steinberger

1996-01-01

156

Saturation Deficit of the Mesophyll Evaporating Surfaces in a Desert Halophyte  

Microsoft Academic Search

The tensions developed in the internal evaporating leaf surfaces were estimated for a desert halophyte, Reaumuria hirtella, growing in its natural habitat. The method was based on the assumption that at zero transpiration the vapor pressure of the inner parts of the leaf was in equilibrium with that of the atmosphere, provided that stomatal resistance was constant during the measuring

P. C. Whiteman; D. Koller

1964-01-01

157

Historic land use influences contemporary establishment of invasive plant species.  

PubMed

The legacy of agricultural land use can have widespread and persistent effects on contemporary landscapes. Although agriculture can lead to persistent changes in soil characteristics and plant communities, it remains unclear whether historic agricultural land use can alter the likelihood of contemporary biological invasions. To understand how agricultural land-use history might interact with well-known drivers of invasion, we conducted factorial manipulations of soil disturbance and resource additions within non-agricultural remnant sites and post-agricultural sites invaded by two non-native Lespedeza species. Our results reveal that variation in invader success can depend on the interplay of historic land use and contemporary processes: for both Lespedeza species, establishment was greater in remnant sites, but soil disturbance enhanced establishment irrespective of land-use history, demonstrating that contemporary processes can help to overcome legacy constraints on invader success. In contrast, additions of resources known to facilitate seedling recruitment (N and water) reduced invader establishment in post-agricultural but not in remnant sites, providing evidence that interactions between historic and contemporary processes can also limit invader success. Our findings thus illustrate that a consideration of historic land use may help to clarify the often contingent responses of invasive plants to known determinants of invasibility. Moreover, in finding significantly greater soil compaction at post-agricultural sites, our study provides a putative mechanism for historic land-use effects on contemporary invasive plant establishment. Our work suggests that an understanding of invasion dynamics requires knowledge of anthropogenic events that often occur decades before the introduction of invasive propagules. PMID:23277213

Mattingly, W Brett; Orrock, John L

2013-08-01

158

Spatial variation of plant communities and shoot Cu concentrations of plant species at a timber treatment site  

Microsoft Academic Search

Plant species, spatial variability in plant diversity and vegetation cover were recorded at a French timber treatment site\\u000a with Cu-contaminated soils (65–2600 mg\\/kg). Shoot biomass, shoot Cu concentration and accumulation were determined for each\\u000a plant species found on 168 quadrats with increasing total Cu in soil and soil solution. A total of 91 species occurred on\\u000a the site including four considered

Clémence M. Bes; Michel Mench; Maurice Aulen; Hélène Gaste; Julie Taberly

2010-01-01

159

Arthropod assemblages on native and nonnative plant species of a coastal reserve in California.  

PubMed

Biological invasions by nonnative plant species are a widespread phenomenon. Many studies have shown strong ecological impacts of plant invasions on native plant communities and ecosystem processes. Far fewer studies have examined effects on associated animal communities. From the perspective of a reserve's land management, I addressed the question of whether arthropod assemblages on two nonnative plant species of concern were impoverished compared with those assemblages associated with two predominant native plant species of that reserve. If the nonnative plant species, Conium maculatum L., and Phalaris aquatica L., supported highly depauperate arthropod assemblages compared with the native plant species, Baccharis pilularis De Candolle and Leymus triticoides (Buckley) Pilger, this finding would provide additional support for prioritizing removal of nonnatives and restoration of natives. I assessed invertebrate assemblages at the taxonomic levels of arthropod orders, Coleoptera families, and Formicidae species, using univariate analyses to examine community attributes (richness and abundance) and multivariate techniques to assess arthropod assemblage community composition differences among plant species. Arthropod richness estimates by taxonomic level between native and nonnative vegetation showed varying results. Overall, arthropod richness of the selected nonnative plants, examined at higher taxonomic resolution, was not necessarily less diverse than two of common native plants found on the reserve, although differences were found among plant species. Impacts of certain nonnative plant species on arthropod assemblages may be more difficult to elucidate than those impacts shown on native plants and ecosystem processes. PMID:20550788

Fork, Susanne K

2010-06-01

160

Arabidopsis Species Hybrids in the Study of Species Differences and Evolution of Amphiploidy in Plants1  

PubMed Central

It is estimated that 5 million years of evolution separate Arabidopsis thaliana from its close relative Arabidopsis lyrata. The two taxa differ by many characteristics, and together they exemplify the differentiation of angiosperms into self-fertilizing and cross-fertilizing species as well as annual and perennial species. Despite their disparate life histories, the two species can be crossed to produce viable and vigorous hybrids exhibiting heterotic effects. Although pollen sterile, the hybrids produce viable ovules and were used as female parent in backcrosses to both parental species. The resulting backcross plants exhibited transgressive variation for a number of interesting developmental and growth traits as well as negative nuclear/cytoplasmic interactions. Moreover, the genesis of a fertile amphidiploid neospecies, apparently by spontaneous somatic doubling in an interspecific hybrid, was observed in the laboratory. The mechanisms responsible for the generation of amphiploids and the subsequent evolution of amphiploid genomes can now be studied through direct observation using the large arsenal of molecular tools available for Arabidopsis.

Nasrallah, Mikhail E.; Yogeeswaran, Krithika; Snyder, Stephen; Nasrallah, June B.

2000-01-01

161

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species  

Microsoft Academic Search

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled

Jin-Hong Qian; Adel Zayed; Yong-Liang Zhu; Mei Yu; Norman Terry

1999-01-01

162

Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners  

PubMed Central

It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native congeners of the family Asteraceae. Our results showed that plant chemistry is highly species-specific and diverse among both exotic and native species. Nonetheless, the exotic species had on average a higher total number of metabolites and more species-unique metabolites compared with their native congeners. Herbivory led to an overall increase in metabolites in all plant species. Generalist herbivore performance was lower on most of the exotic species compared with the native species. We conclude that high chemical diversity and large phytochemical uniqueness of the exotic species could be indicative of biological invasion potential.

Macel, Mirka; de Vos, Ric C H; Jansen, Jeroen J; van der Putten, Wim H; van Dam, Nicole M

2014-01-01

163

Interactions of plant species mediated plant competition for inorganic nitrogen with soil microorganisms in an alpine meadow  

Microsoft Academic Search

Sources of competition for limited soil resources, such as nitrogen, include competitive interactions among different plant\\u000a species and between plants and soil microbes. We hypothesized that plant interactions intensified plant competition for inorganic\\u000a nitrogen with soil microorganisms. To test these competitive interactions, one dominant species (Kobresia humilis Serg) and one less abundant gramineous herb (Elymus nutans Griseb) in an alpine

Minghua Song; Xingliang Xu; Qiwu Hu; Yuqiang Tian; Hua Ouyang; Caiping Zhou

2007-01-01

164

Species richness of yeast communities in floral nectar of southern Spanish plants.  

PubMed

Floral nectar of insect-pollinated plants often contains dense yeast populations, yet little quantitative information exists on patterns and magnitude of species richness of nectar-dwelling yeasts in natural plant communities. This study evaluates yeast species richness at both the plant community and plant species levels in a montane forest area in southern Spain, and also explores possible correlations between the incidence of different yeast species in nectar and their reported tolerance to high sugar concentrations, and between yeast diversity and pollinator composition. Yeast species occurring in a total of 128 field-collected nectar samples from 24 plant species were identified by sequencing the D1/D2 domain of the large subunit rDNA, and rarefaction-based analyses were used to estimate yeast species richness at the plant community and plant species levels, using nectar drops as elemental sampling units. Individual nectar samples were generally characterized by very low species richness (1.2 yeast species/sample, on average), with the ascomycetous Metschnikowia reukaufii and Metschnikowia gruessii accounting altogether for 84.7% of the 216 isolates identified. Other yeasts recorded included species in the genera Aureobasidium, Rhodotorula, Cryptococcus, Sporobolomyces, and Lecythophora. The shapes and slopes of observed richness accumulation curves were quite similar for the nectar drop and plant species approaches, but the two approaches yielded different expected richness estimates. Expected richness was higher for plant species-based than for nectar drop-based analyses, showing that the coverage of nectar yeast species occurring in the region would be improved by sampling additional host plant species. A significant correlation was found between incidence of yeast species in nectar and their reported ability to grow in a medium containing 50% glucose. Neither diversity nor incidence of yeasts was correlated with pollinator composition across plant species. PMID:20449581

Pozo, María I; Herrera, Carlos M; Bazaga, Pilar

2011-01-01

165

Productivity is a poor predictor of plant species richness  

USGS Publications Warehouse

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity an

Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Grace, James B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Calabrese, Laura B.; Chu, Cheng-Jin; Cleland, Elsa E.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Frater, Paul; Gasarch, Eve I.; Gruner, Daneil S.; Hagenah, Nicole; Lambers, Janneke Hille Ris; Humphries, Hope; Jin, Virginia L.; Kay, Adam D.; Kirkman, Kevin P.; Klein, Julia A; Knops, Johannes M. H.; La Pierre, Kimberly J.; Lambrinos, John G.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Mortensen, Brent; Orrock, John L.; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Wang, Gang; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

2011-01-01

166

Productivity Is a Poor Predictor of Plant Species Richness.  

SciTech Connect

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.

Peter B. Adler; et al.

2011-09-22

167

The evolution of cultivated plant species: classical plant breeding versus genetic engineering  

Microsoft Academic Search

Agriculture is the most intensive form of environmental exploitation performed by mankind. It involves replacing the natural\\u000a ecosystem with an artificial plant community comprising one or more crop species, and weeds can invade the cleared land. Initially,\\u000a the adoption of agriculture did not necessarily imply an improvement in standard of living (there is, in fact, evidence to\\u000a the contrary), but

Hakan Ulukan

2009-01-01

168

Photochemical and biophysical feedbacks of C3 and C4 Mediterranean halophytes to atmospheric CO2 enrichment confirmed by their stable isotope signatures.  

PubMed

According the latest predictions, an increase of about two times in atmospheric CO2 concentrations, is expected to occur by the end of this century. In order to understand the effects of this atmospheric composition changes on two abundant Mediterranean halophytes (Halimione portulacoides and Spartina maritima), mesocosmos trials were performed simulating two atmospheric CO2 environments (380 ppm and 760 ppm of CO2 respectively). The two chosen halophyte species present different metabolic characteristics: H. portulacoides, is a C3 specie while S. maritima is a C4 species. Distinct feedbacks were obtained for each of the studied species. Stable Isotope discrimination showed that both species showed an enhancement of the Rubisco carboxylation capacity and photosynthetic efficiency mostly due to an increase in intracellular [CO2]. In H. portulacoides CO2 fertilization induced an enhancement of ETR and a decrease in non-photochemical quenching and in dissipated energy fluxes. On the other hand the C4 grass S. maritima, already at full capacity, showed no photosynthetic enhancement. In fact this highly productive grass presented lower photosynthetic efficiencies accompanied by increases in dissipated energy fluxes mostly due to reductions in energy flux associated with the transport of reducing power throughout the quinone pool. The accumulation of reducing power led to oxidative stress, and thus the photosynthetic ability of this grass was greatly reduced. Both these feedbacks to realistic future CO2 concentrations are important consideration for in future primary productivity models, indicating a possible reduced abundance of the pioneer S. maritima and an increased biomass spreading of the sediment stabilizer H. portulacoides, inevitably affecting the morphology and function of the salt marshes imposed by these atmospheric changes, both in terms of ecosystem functioning and loss of biodiversity. PMID:24713121

Duarte, B; Santos, D; Silva, H; Marques, J C; Caçador, I

2014-07-01

169

Plant species invasions along the latitudinal gradient in the United States  

USGS Publications Warehouse

It has been long established that the richness of vascular plant species and many animal taxa decreases with increasing latitude, a pattern that very generally follows declines in actual and potential evapotranspiration, solar radiation, temperature, and thus, total productivity. Using county-level data on vascular plants from the United States (3000 counties in the conterminous 48 states), we used the Akaike Information Criterion (AIC) to evaluate competing models predicting native and nonnative plant species density (number of species per square kilometer in a county) from various combinations of biotic variables (e.g., native bird species density, vegetation carbon, normalized difference vegetation index), environmental/topographic variables (elevation, variation in elevation, the number of land cover classes in the county; radiation, mean precipitation, actual evapotranspiration, and potential evapotranspiration), and human variables (human population density, crop-land, and percentage of disturbed lands in a county). We found no evidence of a latitudinal gradient for the density of native plant species and a significant, slightly positive latitudinal gradient for the density of nonnative plant species. We found stronger evidence of a significant, positive productivity gradient (vegetation carbon) for the density of native plant species and nonnative plant species. We found much stronger significant relationships when biotic, environmental/topographic, and human variables were used to predict native plant species density and nonnative plant species density. Biotic variables generally had far greater influence in multivariate models than human or environmental/topographic variables. Later, we found that the best, single, positive predictor of the density of nonnative plant species in a county was the density of native plant species in a county. While further study is needed, it may be that, while humans facilitate the initial establishment invasions of nonnative plant species, the spread and subsequent distributions of nonnative species are controlled largely by biotic and environmental factors.

Stohlgren, T.J.; Barnett, D.; Flather, C.; Kartesz, J.; Peterjohn, B.

2005-01-01

170

A new Legionella species, Legionella feeleii species nova, causes Pontiac fever in an automobile plant.  

PubMed

From 15 to 21 August 1981, Pontiac fever affected 317 automobile assembly plant workers. Results of serologic tests were negative for Mycoplasma, Chlamydia, respiratory tract viruses, and previously described legionellae. A gram-negative, rod-shaped organism (WO-44C) that did not grow on blood agar, required L-cysteine for growth, and contained large amounts of branched-chain fatty acids was isolated from a water-based coolant. The organism did not react with antisera against other legionellae, and on DNA hybridization the organism was less than 10% related to other Legionella species. Geometric mean titers found by indirect fluorescent antibody testing to WO-44C were significantly higher in ill employees than in controls (p = 0.0001). Attack rates by department decreased linearly with the department's distance from the implicated coolant system. The etiologic agent apparently was a new Legionella species; we propose the name Legionella feeleii species nova (AATC 35072). This is the first outbreak of nonpneumonic legionellosis in which the etiologic agent is not L. pneumophila, serogroup 1. PMID:6696354

Herwaldt, L A; Gorman, G W; McGrath, T; Toma, S; Brake, B; Hightower, A W; Jones, J; Reingold, A L; Boxer, P A; Tang, P W

1984-03-01

171

Adaptive Management Plan for Sensitive Plant Species on the Nevada Test Site  

Microsoft Academic Search

The Nevada Test Site supports numerous plant species considered sensitive because of their past or present status under the Endangered Species Act and with federal and state agencies. In 1998, the U.S. Department of Energy, Nevada Operation Office (DOE\\/NV) prepared a Resource Management Plan which commits to protects and conserve these sensitive plant species and to minimize accumulative impacts to

C. A. Wills

2001-01-01

172

Effects of three species of Chihuahuan Desert ants on annual plants and soil properties  

Microsoft Academic Search

We tested the hypothesis that ant species, which occupy the same nest for a decade or longer, would modify nest soils by increasing soil nutrients and microorganisms resulting in increased biomass, density, cover and species richness of annual plants. We measured soil properties and annual plants on nest soils of three species of Chihuahuan Desert ants (Pogonomyrmex rugosus—seed harvester, Aphaenogaster

W. G. Whitford; G. Barness; Y. Steinberger

2008-01-01

173

Effects of coexisting plant species on soil microbes and soil enzymes in metal lead contaminated soils  

Microsoft Academic Search

It is not clear whether plant species coexistence can offset the impacts of heavy metal lead (Pb) on soil microbes and soil enzyme activities. We conducted a factorial experiment to investigate the effects of three plant species combinations (1, 2 and 4 species) on soil microbial and soil enzyme properties under three Pb concentrations (0, 300 and 600mgkg?1 soil). Microbial

Ruyi Yang; Jianjun Tang; Xin Chen; Shuijin Hu

2007-01-01

174

Spatial variation in insect community and species responses to habitat loss and plant community composition  

Microsoft Academic Search

Several experimental studies have examined species responses to manipulations of habitat area and spatial arrangement, but plant composition and spatial variation in species distributions also affect animal responses to habitat alteration. We used an experimental approach to study the combined effects of habitat area, edge, and plant community composition on the spatial structure of insect species richness and composition. The

Thomas O. Crist; Sharmila V. Pradhan-Devare; Keith S. Summerville

2006-01-01

175

Comparative drought-resistance of seedlings of 28 species of co-occurring tropical woody plants  

Microsoft Academic Search

Quantifying plant drought resistance is important for understanding plant species' association to microhabitats with different soil moisture availability and their distribution along rainfall gradients, as well as for understanding the role of underlying morphological and physiological mechanisms. The effect of dry season drought on survival and leaf-area change of first year seedlings of 28 species of co-occurring woody tropical plants

Bettina M. J. Engelbrecht; Thomas A. Kursar

2003-01-01

176

Mercury bioaccumulation and phytotoxicity in two wild plant species of Almadén area  

Microsoft Academic Search

Mercury is a widely distributed environmental pollutant, able to induce toxicity in living organisms, including higher plants. Some plant species are able to grow in mine sites, like the Almadén zone in Spain. Our study focus on two of these plant species, Rumex induratus and Marrubium vulgare and their responses to natural Hg exposure. Total Hg concentration in the soil

E. Moreno-Jiménez; R. Gamarra; R. O. Carpena-Ruiz; R. Millán; J. M. Peñalosa; E. Esteban

2006-01-01

177

Quantifying empirical relations between planted species mixtures and canopy reflectance with PROTEST  

Microsoft Academic Search

Mapping plant species composition of mixed vegetation stands with remote sensing is a complicated task. Uncertainties may arise from similar spectral signatures of different plant species as well as from variable influences of prevailing plant states (e.g., growth stages, vigor, or stress levels). Despite these uncertainties, empirical approaches may often be able to take up the challenge. However, their performance

Hannes Feilhauer; Erich-Christian Oerke; Sebastian Schmidtlein

2010-01-01

178

Comparison of relative antioxidant activities of British medicinal plant species in vitro  

Microsoft Academic Search

We have determined the relative levels of endogenous antioxidant activity in a range of British medicinal plant species (representative of a variety of plant families, selected on the basis of their widespread use in traditional herbal medicine), via competitive scavenging of the ABTS+ or O2? radicals in vitro. A number of plant species with appreciable levels (i.e. greater than or

David Mantle; Fadel Eddeb; Anne T. Pickering

2000-01-01

179

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions  

PubMed Central

Traits that permit successful invasions have often seemed idiosyncratic, and the key biological traits identified vary widely among species. This fundamentally limits our ability to determine the invasion potential of a species. However, ultimately, successful invaders must have positive growth rates that longer term result in higher biomass accumulation than competing established species. In many terrestrial ecosystems nitrogen limits plant growth, and is a key factor determining productivity and the outcome of competition among species. Plant nitrogen use may provide a powerful framework to evaluate the invasive potential of a species in nitrogen-limiting ecosystems. Six mechanisms influence plant nitrogen use or acquisition: photosynthetic tissue allocation, photosynthetic nitrogen use efficiency, nitrogen fixation, nitrogen-leaching losses, gross nitrogen mineralization, and plant nitrogen residence time. Here we show that among these alternatives, the key mechanism allowing invasion for Pinus strobus into nitrogen limited grasslands was its higher nitrogen residence time. This higher nitrogen residence time created a positive feedback that redistributed nitrogen from the soil into the plant. This positive feedback allowed P. strobus to accumulate twice as much nitrogen in its tissues and four times as much nitrogen to photosynthetic tissues, as compared with other plant species. In turn, this larger leaf nitrogen pool increased total plant carbon gain of P. strobus two- to sevenfold as compared with other plant species. Thus our data illustrate that plant species can change internal ecosystem nitrogen cycling feedbacks and this mechanism can allow them to gain a competitive advantage over other plant species.

Laungani, Ramesh; Knops, Johannes M. H.

2009-01-01

180

Contribution of different grass species to plant-atmosphere ammonia exchange in intensively managed grassland  

Microsoft Academic Search

Species diversity in grasslands usually declines with increasing input of nitrogen from fertilizers or atmospheric deposition. Conversely, species diversity may also impact the build-up of soil and plant nitrogen pools. One important pool is NH3\\/NH4+ which also can be exchanged between plant leaves and the atmosphere. Limited information is available on how plant-atmosphere ammonia exchange is related to species diversity

M. Mattsson; B. Herrmann; S. Jones; A. Neftel; M. A. Sutton; J. K. Schjoerring

2009-01-01

181

Wild edible plants of the Sikkim Himalaya: Nutritive values of selected species  

Microsoft Academic Search

Wild edible plants form an important constituent of traditional diets in the Himalaya. In the Sikkim Himalaya a total of 190\\u000a species have been screened as edible species out of which nearly 47 species come to the market. The present paper deals with\\u000a nutritive values of 27 most commonly consumed wild edible plants in the Sikkim Himalaya. Of 27 plant

Manju Sundriyal; R. C. Sundriyal

2004-01-01

182

Plant species richness in the Cape Verde Islands—eco-geographical determinants  

Microsoft Academic Search

Plant species richness in the Cape Verde archipelago is examined relative to island eco-geographical factors. Species-area\\u000a and species-area-habitat relationships are analysed using the classical species-area model and the recently proposed species-choros\\u000a model. The number of floristic zones (used to estimate the choros parameter) provides an adequate estimate of the potential\\u000a habitat diversity, and the species-choros model achieved a better fit

Maria Cristina Duarte; Francisco Rego; Maria Manuel Romeiras; Ilídio Moreira

2008-01-01

183

Influence of Wildland Fire on the Recovery of Endangered Plant Species Study Project.  

National Technical Information Service (NTIS)

A wildfire swept through the Kipuka Kalawamauna Endangered Plants Habitat Area (KKEPHA) at the Pohakuloa Training Area, Hawaii on 25 through 27 July 1994. About 65% of the area burned. The fire potentially could have impacted rare plant species (Haplostac...

R. Shaw

1995-01-01

184

Performance of dryland and wetland plant species on extensive green roofs  

PubMed Central

Background and Aims Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Methods Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Key Results Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Conclusions Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further evidence that plant composition and diversity can influence green roof functions.

MacIvor, J. Scott; Ranalli, Melissa A.; Lundholm, Jeremy T.

2011-01-01

185

Plant species used in traditional smallholder dairy processing in East Shoa, Ethiopia  

Microsoft Academic Search

Plant species used in traditional dairy processing were studied in three districts (Bosset, Ada, and Gimbichu) in Eastern\\u000a Shoa, Ethiopia, from October 2007 to March 2008. A total of 300 smallholders were interviewed using semi-structured questionnaires,\\u000a and three focus group discussions were conducted, followed by plants specimen collection and identification. A total of 36\\u000a plant species, falling under 24 plant

Hailemariam Mekonnen; A. Lemma

2011-01-01

186

Arbuscular mycorrhizal fungi species-specifically affect induced plant responses to a spider mite  

Microsoft Academic Search

It is widely recognized that arbuscular mycorrhizal fungi (AMF) improve plant growth and nutrient conditions, but their effects\\u000a can vary from negative to positive depending on AMF species. Since the performance of herbivorous arthropods varies with plant\\u000a quality, different AMF species should differently affect the density of herbivorous arthropods on plants and the herbivore-induced\\u000a plant responses. We examined the indirect

Takaaki Nishida; Noboru Katayama; Naoyuki Izumi; Takayuki Ohgushi

2010-01-01

187

GLK gene pairs regulate chloroplast development in diverse plant species.  

PubMed

Chloroplast biogenesis is a complex process that requires close co-ordination between two genomes. Many of the proteins that accumulate in the chloroplast are encoded by the nuclear genome, and the developmental transition from proplastid to chloroplast is regulated by nuclear genes. Here we show that a pair of Golden 2-like (GLK) genes regulates chloroplast development in Arabidopsis. The GLK proteins are members of the GARP superfamily of transcription factors, and phylogenetic analysis demonstrates that the maize, rice and Arabidopsis GLK gene pairs comprise a distinct group within the GARP superfamily. Further phylogenetic analysis suggests that the gene pairs arose through separate duplication events in the monocot and dicot lineages. As in rice, AtGLK1 and AtGLK2 are expressed in partially overlapping domains in photosynthetic tissue. Insertion mutants demonstrate that this expression pattern reflects a degree of functional redundancy as single mutants display normal phenotypes in most photosynthetic tissues. However, double mutants are pale green in all photosynthetic tissues and chloroplasts exhibit a reduction in granal thylakoids. Products of several genes involved in light harvesting also accumulate at reduced levels in double mutant chloroplasts. GLK genes therefore regulate chloroplast development in diverse plant species. PMID:12220263

Fitter, David W; Martin, David J; Copley, Martin J; Scotland, Robert W; Langdale, Jane A

2002-09-01

188

Reactive oxygen species mediate growth and death in submerged plants  

PubMed Central

Aquatic and semi-aquatic plants are well adapted to survive partial or complete submergence which is commonly accompanied by oxygen deprivation. The gaseous hormone ethylene controls a number of adaptive responses to submergence including adventitious root growth and aerenchyma formation. Reactive oxygen species (ROS) act as signaling intermediates in ethylene-controlled submergence adaptation and possibly also independent of ethylene. ROS levels are controlled by synthesis, enzymatic metabolism, and non-enzymatic scavenging. While the actors are by and large known, we still have to learn about altered ROS at the subcellular level and how they are brought about, and the signaling cascades that trigger a specific response. This review briefly summarizes our knowledge on the contribution of ROS to submergence adaptation and describes spectrophotometrical, histochemical, and live cell imaging detection methods that have been used to study changes in ROS abundance. Electron paramagnetic resonance (EPR) spectroscopy is introduced as a method that allows identification and quantification of specific ROS in cell compartments. The use of advanced technologies such as EPR spectroscopy will be necessary to untangle the intricate and partially interwoven signaling networks of ethylene and ROS.

Steffens, Bianka; Steffen-Heins, Anja; Sauter, Margret

2013-01-01

189

Plant species identity surpasses species richness as a key driver of N(2)O emissions from grassland.  

PubMed

Grassland ecosystems worldwide not only provide many important ecosystem services but they also function as a major source of the greenhouse gas nitrous oxide (N2O), especially in response to nitrogen deposition by grazing animals. To explore the role of plants as mediators of these emissions, we tested whether and how N2O emissions are dependent on grass species richness and/or specific grass species composition in the absence and presence of urine deposition. We hypothesized that: (i) N2O emissions relate negatively to plant productivity; (ii) four-species mixtures have lower emissions than monocultures (as they are expected to be more productive); (iii) emissions are lowest in combinations of species with diverging root morphology and high root biomass; and (iv) the identity of the key species that reduce N2O emissions is dependent on urine deposition. We established monocultures and two- and four-species mixtures of common grass species with diverging functional traits: Lolium perenne L. (Lp), Festuca arundinacea Schreb. (Fa), Phleum pratense L. (Php) and Poa trivialis L. (Pt), and quantified N2O emissions for 42 days. We found no relation between plant species richness and N2O emissions. However, N2O emissions were significantly reduced in specific plant species combinations. In the absence of urine, plant communities of Fa+Php acted as a sink for N2O, whereas the monocultures of these species constituted a N2O source. With urine application Lp+Pt plant communities reduced (P < 0.001) N2O emissions by 44% compared to monocultures of Lp. Reductions in N2O emissions by species mixtures could be explained by total biomass productivity and by complementarity in root morphology. This study shows that plant species composition is a key component underlying N2O emissions from grassland ecosystems. Selection of specific grass species combinations in the context of the expected nitrogen deposition regimes may therefore provide a key for mitigation of N2O emissions. PMID:23939815

Abalos, Diego; De Deyn, Gerlinde B; Kuyper, Thomas W; Van Groenigen, Jan Willem

2014-01-01

190

Towards a ‘red list’ for crop plant species  

Microsoft Academic Search

An attempt is made toward the application of IUCN criteria and Red List Categories to agricultural and horticultural plants (excluding ornamentals). The main sources for this study were Mansfeld’s Encyclopedia (2001) and the IUCN Red List of threatened plants (2001). About 200 threatened cultivated plants are considered and presented in the respective lists, among them completely extinct crop plants such

Karl Hammer; Korous Khoshbakht

2005-01-01

191

Highly efficient Agrobacterium -based transformation system for callus cells of the C 3 halophyte Suaeda salsa  

Microsoft Academic Search

Genetic manipulation technologies have been limited in the halophyte Suaeda salsa L. due to the lack of an efficient transformation system. Here, we examined factors affecting transformation and developed\\u000a an efficient transformation system at the cell level using S. salsa hypocotyl as starting material. S. salsa hypocotyl explants from 10-day-old seedlings were precultured for 2 days on a hygromycin (hyg)-free callus

Shu-Zhen Zhao; Yuan Ruan; Hong-Zhao Sun; Bao-Shan Wang

2008-01-01

192

Characterization of a DRE-binding transcription factor from a halophyte Atriplex hortensis  

Microsoft Academic Search

Environmental stresses, such as salinity, drought and cold, can induce the expression of a large amount of genes. Among these are many transcription factors that regulate the expression of downstream genes by specifically binding to cis-elements or forming transcriptional complexes with other proteins. In the present study, a DREB-like transcription factor gene, named AhDREB1, was isolated from a halophyte Atriplex

Yi-Guo Shen; Wan-Ke Zhang; Dong-Qing Yan; Bao-Xing Du; Jin-Song Zhang; Qiang Liu; Shou-Yi Chen

2003-01-01

193

Screening Indian plant species for antiplasmodial properties--ethnopharmacological compared with random selection.  

PubMed

In the search for biologically active plant species, many studies have shown that an ethnopharmacological approach is more effective than a random collection. In order to determine whether this is true in the case of plant species used for the treatment of malaria in Orissa, India, the antiplasmodial activities of extracts prepared from 25 traditionally used species were compared with those of 25 species collected randomly. As expected, plant species used traditionally for the treatment of malaria were more likely to exhibit antiplasmodial activity (21 species (84%) active against Plasmodium falciparum strain 3D7) than plant species collected randomly (9 species (32%)). However, of the nine active randomly collected species, eight had not previously been reported to possess antiplasmodial activity while one inactive species had been reported to be active in another study. Of the 21 active species of traditional antimalarial treatments, only six had been reported previously. This study suggests that while the selection of traditional medicinal plants is more predictive of antiplasmodial study, random collections may still be of value for the identification of new antiplasmodial species. PMID:22407797

Kantamreddi, Venkata Siva Satyanarayana; Wright, Colin W

2012-12-01

194

Measuring the effects of invasive species on the demography of a rare endemic plant  

Microsoft Academic Search

The impacts of invasive species are among the greatest threats to the persistence of native species and communities. Yet most work on rare plants has focused on issues such as habitat fragmentation and genetic diversity, while few studies have quantified the impacts of invasive plants on native ones or investigated the underlying mechanisms of those impacts. I used removal experiments

Diane Thomson

2005-01-01

195

Plant and insect diversity along a pollution gradient: understanding species richness across trophic levels  

Microsoft Academic Search

We analysed species richness of plants and true bugs (Insecta, Heteroptera) along a pollution gradient in Scots pine stands in Central Germany. As a consequence of particulate deposition, pH-values of soils increased in the vicinity of the emission source. Therefore, emission increased productivity. Species richness of plants increased with decreasing distance from emission source, and thus with increasing productivity. Similarly,

Martin Brändle; Uwe Amarell; Harald Auge; Stefan Klotz; Roland Brandl

2001-01-01

196

Quality over quantity: buffer strips can be improved with select native plant species.  

PubMed

Native plants attractive to beneficial insects may improve the value of buffer strips by increasing biodiversity and enhancing the delivery of insect-derived ecosystem services. In a 2-yr field experiment, we measured the response of insect communities across nine buffers that varied in plant diversity. We constructed buffers with plants commonly found in buffers of USDA-certified organic farms in Iowa (typically a single species), recommended for prairie reconstruction, or recommended for attracting beneficial insects. We hypothesized that the diversity and abundance of beneficial insects will be 1) greatest in buffers composed of diverse plant communities with continuous availability of floral resources, 2) intermediate in buffers with reduced species richness and availability of floral resources, and 3) lowest in buffers composed of a single species. We observed a significant positive relationship between the diversity and abundance of beneficial insects with plant community diversity and the number of flowers. More beneficial insects were collected in buffers composed of species selected for their attractiveness to beneficial insects than a community recommended for prairie restoration. These differences suggest 1) plant communities that dominate existing buffers are not optimal for attracting beneficial insects, 2) adding flowering perennial species could improve buffers as habitat for beneficial insects, 3) buffers can be optimized by intentionally combining the most attractive native species even at modest levels of plant diversity, and 4) plant communities recommended for prairie reconstruction may not contain the optimal species or density of the most attractive species necessary to support beneficial insects from multiple guilds. PMID:24763090

Gill, K A; Cox, R; O'Neal, M E

2014-04-01

197

Nutritional and cultural aspects of plant species selection for a controlled ecological life support system  

NASA Technical Reports Server (NTRS)

The feasibility of using higher plants in a controlled ecological life support system is discussed. Aspects of this system considered important in the use of higher plants include: limited energy, space, and mass, and problems relating to cultivation and management of plants, food processing, the psychological impact of vegetarian diets, and plant propagation. A total of 115 higher plant species are compared based on 21 selection criteria.

Hoff, J. E.; Howe, J. M.; Mitchell, C. A.

1982-01-01

198

Cooccurring plants forming distinct arbuscular mycorrhizal morphologies harbor similar AM fungal species.  

PubMed

Arbuscular mycorrhizal (AM) fungal spores were isolated from field transplants and rhizosphere soil of Hedera rhombea (Miq) Bean and Rubus parvifolius L., which form Paris-type and Arum-type AM, respectively. DNA from the spore isolates was used to generate molecular markers based on partial large subunit (LSU) ribosomal RNA (rDNA) sequences to determine AM fungi colonizing field-collected roots of the two plant species. Species that were isolated as spores and identified morphologically and molecularly were Gigaspora rosea and Scutellospora erythropa from H. rhombea, Acaulospora longula and Glomus etunicatum from R. parvifolius, and Glomus claroideum from both plants. The composition of the AM fungal communities with respect to plant trap cultures was highly divergent between plant species. Analysis of partial LSU rDNA sequences amplified from field-collected roots of the two plant species with PCR primers designed for the AM fungi indicated that both plants were colonized by G. claroideum, G. etunicatum, A. longula, and S. erythropa. G. rosea was not detected in the field-collected roots of either plant species. Four other AM fungal genotypes, which were not isolated as spores in trap cultures from the two plant species, were also found in the roots of both plant species; two were closely related to Glomus intraradices and Glomus clarum. One genotype, which was most closely related to Glomus microaggregatum, was confined to R. parvifolius, whereas an uncultured Glomeromycotan fungus occurred only in roots of H. rhombea. S. erythropa was the most dominant fungus found in the roots of H. rhombea. The detection of the same AM fungal species in field-collected roots of H. rhombea and R. parvifolius, which form Paris- and Arum-type AM, respectively, shows that AM morphology in these plants is strongly influenced by the host plant genotypes as appears to be the case in many plant species in natural ecosystems, although there are preferential associations between the hosts and colonizing AM fungi in this study. PMID:17106725

Matekwor Ahulu, Evelyn; Gollotte, Armelle; Gianinazzi-Pearson, Vivienne; Nonaka, Masanori

2006-12-01

199

Rooting Cuttings of Shrub Species for Plantings in California Wildlands.  

National Technical Information Service (NTIS)

Selected shrub species are being studied in southern California for their possible fuel volume or slow burning characteristics. In propagation tests, five species--fourwing, Gardner's, Nuttall's, and allscale saltbushes' and creeping sage--rooted successf...

E. C. Nord J. R. Goodin

1970-01-01

200

Species richness of arbuscular mycorrhizal fungi: associations with grassland plant richness and biomass.  

PubMed

Although experiments show a positive association between vascular plant and arbuscular mycorrhizal fungal (AMF) species richness, evidence from natural ecosystems is scarce. Furthermore, there is little knowledge about how AMF richness varies with belowground plant richness and biomass. We examined relationships among AMF richness, above- and belowground plant richness, and plant root and shoot biomass in a native North American grassland. Root-colonizing AMF richness and belowground plant richness were detected from the same bulk root samples by 454-sequencing of the AMF SSU rRNA and plant trnL genes. In total we detected 63 AMF taxa. Plant richness was 1.5 times greater belowground than aboveground. AMF richness was significantly positively correlated with plant species richness, and more strongly with below- than aboveground plant richness. Belowground plant richness was positively correlated with belowground plant biomass and total plant biomass, whereas aboveground plant richness was positively correlated only with belowground plant biomass. By contrast, AMF richness was negatively correlated with belowground and total plant biomass. Our results indicate that AMF richness and plant belowground richness are more strongly related with each other and with plant community biomass than with the plant aboveground richness measures that have been almost exclusively considered to date. PMID:24641509

Hiiesalu, Inga; Pärtel, Meelis; Davison, John; Gerhold, Pille; Metsis, Madis; Moora, Mari; Opik, Maarja; Vasar, Martti; Zobel, Martin; Wilson, Scott D

2014-07-01

201

Plant Species Loss Affects Life-History Traits of Aphids and Their Parasitoids  

PubMed Central

The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers.

Petermann, Jana S.; Roscher, Christiane; Weigelt, Alexandra; Weisser, Wolfgang W.; Schmid, Bernhard

2010-01-01

202

Invasive Plant Species and the Joint Fire Science Program.  

National Technical Information Service (NTIS)

Invasive nonnative plants may be responsible for serious, long-term ecological impacts, including altering fire behavior and fire regimes. Therefore, knowing how to successfully manage invasive plants and their impacts on natural resources is crucial. We ...

H. Erickson

2007-01-01

203

Plant species mediate changes in soil microbial N in response to elevated CO{sub 2}  

SciTech Connect

The effect of elevated CO{sub 2} on plant-microbial interactions and nitrogen (N) cycling is critical to predicting plant growth responses to elevated CO{sub 2}, because plant growth is often N-limited. We investigated whether the effects of elevated CO{sub 2} on plant-microbial N dynamics differed among six annual plant species: three European grasses that have invaded California grasslands, and one grass and two forbs native to California serpentine grassland. Elevated CO{sub 2} altered plant N pools and {sup 15}NH{sub 4}{sup +} uptake, but the direction and magnitude of the changes were species dependent. The introduced grasses showed increased plant N pools and {sup 15}NH{sub 4}{sup +} uptake, whereas the native species showed smaller increases or even decreases in plant N pools and {sup 15}NH{sub 4}{sup +} uptake. Under nutrient enrichment, soil microbial N and {sup 15}NH{sub 4}{sup +} uptake differed among soils with different plant species, but they were not affected by elevated CO{sub 2}. At low nutrients, elevated CO{sub 2} altered soil microbial N and {sup 15}NH{sub 4}{sup +} uptake differed among soils with different plant species, but they were not affected by elevated CO{sub 2}. At low nutrients, elevated CO{sub 2} altered soil microbial N and {sup 15}NH{sub 4}{sup +} uptake, but the direction and magnitude of the changes were species dependent. The changes in soil microbial N were positively correlated with changes were species dependent. The changes in soil microbial N were positively correlated with changes in the plant N pool, suggesting that there was no trade-off in N uptake between plants and microbes. These results also suggest that plant species composition will partly determine the direction of changes in coil N cycling in response to elevated CO{sub 2}. 38 refs., 4 figs., 5 tabs.

Hungate, B.A.; Canadell, J.; Chapin, F.S. III [Univ. of California, Berkeley, CA (United States)

1996-12-01

204

The Application of Reverse Genetics to Polyploid Plant Species  

Microsoft Academic Search

Polyploidy events (polyploidization) followed by progressive loss of redundant genome components are a major feature of plant evolution, with new evidence suggesting that all flowering plants possess ancestral genome duplications. Furthermore, many of our most important crop plants have undergone additional, relatively recent, genome duplication events. Recent advances in DNA sequencing have made vast amounts of new genomic data available

Timothy L. Fitzgerald; Kemal Kazan; John M. Manners

2012-01-01

205

Investigating Effects of Invasive Species on Plant Community Structure  

ERIC Educational Resources Information Center

In this article, the author presents a field study project that explores factors influencing forest community structure and lifts the veil off of "plant blindness." This ecological study consists of three laboratories: (1) preliminary field trip to the study site; (2) plant survey; and (3) analyzing plant community structure with descriptive…

Franklin, Wilfred

2008-01-01

206

Over-expression of the peroxisomal ascorbate peroxidase (SbpAPX) gene cloned from halophyte Salicornia brachiata confers salt and drought stress tolerance in transgenic tobacco.  

PubMed

Salicornia brachiata Roxb., an extreme halophyte, is a naturally adapted higher plant model for additional gene resources to engineer salt tolerance in plants. Ascorbate peroxidase (APX) plays a key role in protecting plants against oxidative stress and thus confers abiotic stress tolerance. A full-length SbpAPX cDNA, encoding peroxisomal ascorbate peroxidase, was cloned from S. brachiata. The open reading frame encodes for a polypeptide of 287 amino acid residues (31.3-kDa protein). The deduced amino acid sequence of the SbpAPX gene showed characteristic peroxisomal targeting sequences (RKRAI) and a C-terminal hydrophobic region of 39 amino acid residues containing a transmembrane domain (TMD) of 23 amino acid residues. Northern blot analysis showed elevated SbpAPX transcript in response to salt, cold, abscisic acid and salicylic acid stress treatments. The SbpAPX gene was transformed to tobacco for their functional validation under stresses. Transgenic plants over-expressing SbpAPX gene showed enhanced salt and drought stress tolerance compared to wild-type plants. Transgenic plants showed enhanced vegetative growth and germination rate both under normal and stressed conditions. Present study revealed that the SbpAPX gene is a potential candidate, which not only confers abiotic stress tolerance to plants but also seems to be involved in plant growth. PMID:24197564

Singh, Natwar; Mishra, Avinash; Jha, Bhavanath

2014-06-01

207

Are non-native plants perceived to be more risky? Factors influencing horticulturists' risk perceptions of ornamental plant species.  

PubMed

Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N?=?625) to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species. PMID:25003195

Humair, Franziska; Kueffer, Christoph; Siegrist, Michael

2014-01-01

208

Are Non-Native Plants Perceived to Be More Risky? Factors Influencing Horticulturists' Risk Perceptions of Ornamental Plant Species  

PubMed Central

Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N?=?625) to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species.

Humair, Franziska; Kueffer, Christoph; Siegrist, Michael

2014-01-01

209

Plant Species Richness and Nitrogen Deposition can Alter Microbial Assimilation of New Photosynthate  

NASA Astrophysics Data System (ADS)

Microbial assimilation of recent photosynthate was analyzed in a 6-year-long field experiment to determine how plant species richness impacts microbial metabolism of new photosynthate, and how this may be modified by atmospheric N deposition. Our study was conducted at the BioCON (Biodiversity, CO2, and Nitrogen) FACE (Free-Air Carbon dioxide Enrichment) experiment located at the Cedar Creek Natural History area in Minnesota, USA. In this experiment, plant species richness, atmospheric N deposition, and atmospheric CO2 concentration were manipulated in concert. The depleted ?13C of fumigation CO2 enabled us to investigate the effect of plant species richness and atmospheric N deposition on the metabolism of soil microbial communities in the elevated CO2 treatment. We determined the ?13C of bacterial, actinobacterial, and fungal phospholipid fatty acids (PLFA). In the elevated CO2 conditions of this study, the ?13C of bacterial PLFAs (i15:0, i16:0, 16:1?7c, 16:1?9c, 10Me16:0, and 10Me18:0) and the fungal PLFA 18:1?9c was significantly lower in species-rich plant communities than in species-poor plant communities, indicating that microbial incorporation of new C increased with plant species richness. Despite an increase in plant production, total PLFA decreased under N deposition by 27%. Moreover, N deposition also decreased fungal relative abundance in species-rich plant communities. In our study, plant species richness directly increased microbial incorporation of new photosynthate, providing a mechanistic link between greater plant detritus production in species-rich plant communities and larger and more active soil microbial community.

Chung, H.; Zak, D.; Reich, P.

2009-12-01

210

Wild edible plants of the Sikkim Himalaya: Nutritive values of selected species  

Microsoft Academic Search

The wild edible plants form an important constituent of traditional diets in the Himalaya. In the Sikkim Himalaya a total\\u000a of 190 species have been screened as edible species out of which nearly 47 species come to the market. The present paper deals\\u000a with nutritive values of 27 most commonly consumed wild edible plants in the Sikkim Himalaya. Of 27

Manju Sundriyal; R. C. Sundriyal

2001-01-01

211

Biomonitoring of chemical elements in an urban environment using arboreal and bush plant species  

Microsoft Academic Search

Purpose  The aim of this work was to investigate the possibility of using several bush and arboreal plant species, usually present\\u000a as ornamental plants in street and parks, as environmental indicators of pollution. This is a research paper that evaluates\\u000a the real possibility of using a fast and low-cost procedure to evaluate the pollution degree through data obtained from plant\\u000a species

Maria Isabel Rucandio; Maria Dolores Petit-Domínguez; Concepcion Fidalgo-Hijano; Rosario García-Giménez

2011-01-01

212

Emission of isoprene from common Indian plant species and its implications for regional air quality  

Microsoft Academic Search

Isoprene is most dominant volatile organic compounds (VOC) emitted by many plants. In this study 40 common Indian plant species\\u000a were examined for isoprene emission using dynamic flow through enclosure chamber technique. Isoprene emission rates of plants\\u000a species were found to vary from undetectable to 69.5 ?g g?1 h?1 (Madhuca latifolia). Besides, an attempt has been made to evaluate suitability of

Rashmi Singh; Abhai Pratap Singh; M. P. Singh; Animesh Kumar; C. K. Varshney

2008-01-01

213

Plant Species Identification Using Multi-scale Fractal Dimension Applied to Images of Adaxial Surface Epidermis  

NASA Astrophysics Data System (ADS)

This paper presents the study of computational methods applied to histological texture analysis in order to identify plant species, a very difficult task due to the great similarity among some species and presence of irregularities in a given species. Experiments were performed considering 300 ×300 texture windows extracted from adaxial surface epidermis from eight species. Different texture methods were evaluated using Linear Discriminant Analysis (LDA). Results showed that methods based on complexity analysis perform a better texture discrimination, so conducting to a more accurate identification of plant species.

Backes, André R.; de M. Sá Junior, Jarbas J.; Kolb, Rosana M.; Bruno, Odemir M.

214

Nonwoody life-form contribution to vascular plant species richness in a tropical American forest  

Microsoft Academic Search

We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in\\u000a central Bolivia. Species richness ranged from 297 species and 22,360 individuals\\/ha in the dry deciduous forest to 382 species\\u000a and 31,670 individuals\\/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich\\u000a major plant groups in each plot, and Peperomia (Piperaceae),

Reynaldo Linares-Palomino; Victor Cardona; Ernest I. Hennig; Isabell Hensen; Doreen Hoffmann; Jasmin Lendzion; Daniel Soto; Sebastian K. Herzog; Michael Kessler

215

Nonwoody life-form contribution to vascular plant species richness in a tropical American forest  

Microsoft Academic Search

We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in\\u000a central Bolivia. Species richness ranged from 297 species and 22,360 individuals\\/ha in the dry deciduous forest to 382 species\\u000a and 31,670 individuals\\/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich\\u000a major plant groups in each plot, and Peperomia (Piperaceae),

Reynaldo Linares-Palomino; Victor Cardona; Ernest I. Hennig; Isabell Hensen; Doreen Hoffmann; Jasmin Lendzion; Daniel Soto; Sebastian K. Herzog; Michael Kessler

2009-01-01

216

Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.  

PubMed

Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

2014-01-01

217

Students’ Perception of Plant and Animal Species: A Case Study From Rural Argentina  

Microsoft Academic Search

Exotic species seriously affect local biodiversity in Argentina. This article investigates how students in San Juan province perceive native and exotic species. With the help of a written questionnaire, 865 students (9–17 years old) were asked to name the plant and animal they liked most, disliked most, and perceived as most useful, and to name local species and describe their

Juliana Nates; Claudia Campos; Petra Lindemann-Matthies

2010-01-01

218

?????????????????? ????????????????????????????????????????????????????? Species Diversity of Edible Mushrooms and Plants at Sakaerat Biosphere Reserve  

Microsoft Academic Search

The study of species diversity and distribution of edible mushrooms and plants was carried out at Sakaerat Biosphere Reserve, Nakhon Ratchasima, by participatory action research during September 2004 to August 2005. Thirty species from 8 families of edible mushrooms were found in the deciduous dipterocarp forest, dry evergreen forest, and reforest plantation. The dominant species of mushrooms were Russula spp.(Fam.

Sujitra Kosol; Tantima Kumlung; Tanapak Inyod; Pongmanee Thongbai; Taksin Archavacom

219

Could resistance to transgenic plants produce a new species of insect pest?  

Microsoft Academic Search

Recent studies have shown developmental asynchrony between Bacillus thuringiensis resistant and susceptible strains to occur in two insect species, the pink bollworm (Pectinophora gossypella) and the diamondback moth (Plutella xylostella). With the widespread planting of B. thuringiensis transgenic crops, individuals of many pest species will be exposed to intense and continuous selection pressure. In species with such ecological adaptation to

H. Cerda; D. J. Wright

2002-01-01

220

Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities  

ERIC Educational Resources Information Center

Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

2013-01-01

221

Cytogenetic analysis of hairy root cultures from a number of plant species transformed by Agrobacterium rhizogenes  

Microsoft Academic Search

Hairy root cultures, obtained after transformation of seven plant species by A. rhizogenes, were examined cytologically to assess their chromosome number. All species had the correct 2n diploid number of chromosomes in root tip cells. Free cell suspensions of two of the species were also examined and were found to be variable with polyploids or aneuploids predominating. The DNA from

E. L. H. Aird; J. D. Hamill; M. J. C. Rhodes

1988-01-01

222

Fifteen-Year Growth of Six Planted Hardwood Species on Sharkey Clay Soil.  

National Technical Information Service (NTIS)

Six hardwood species planted on Sharkey clay soil that had been disked the first 5 years for weed control were significantly taller at age 5 when compared to species grown on mowed sites. By age 15, there were no differences in heights within species exce...

R. M. Krinard H. E. Kennedy

1987-01-01

223

Site and species-specific differences in endophyte occurrence in two herbaceous plants  

Microsoft Academic Search

Summary 1 Endophyte fungi exist within the living tissues of all plants, but compared with grasses and trees, remarkably little is known about their ecology in herbaceous species. These fungi produce an array of metabolites in culture and there is some evidence that they can increase the resistance of plants to herbivorous insects. 2 As herbaceous plant endophytes are thought

ALAN C. GANGE; SOMA DEY; AMANDA F. CURRIE; BRIAN C. SUTTON

2007-01-01

224

Carbon cycling traits of plant species are linked with mycorrhizal strategy  

Microsoft Academic Search

Ecosystem carbon cycling depends strongly on the productivity of plant species and the decomposition rates of the litter they produce. We tested the hypothesis that classifying plant functional types according to mycorrhizal association explains important interspecific variation in plant carbon cycling traits, particularly in those traits that feature in a hypothesized feedback between vegetation productivity and litter turnover. We compared

J. H. C. Cornelissen; R. Aerts; B. Cerabolini; M. J. A. Werger; M. G. A. van der Heijden

2001-01-01

225

CHLOROPLAST matK GENE PHYLOGENY OF SOME IMPORTANT SPECIES OF PLANTS  

Microsoft Academic Search

In this study using the chloroplast matK DNA sequence, a chloroplast-encoded locus that has been shown to be much more variable than many other genes, from one hundred and forty two plant species belong to the families of 26 plants we conducted a study to contribute to the understanding of major evolutionary relationships among the studied plant orders, families genus

Mehmet KARACA; A. Naci ONUS

226

A proposed classification of invasive alien plant species in South Africa: towards prioritizing species and areas for management action  

Microsoft Academic Search

Many invasive alien plant species in South Africa are already well-established and cause substantial damage, while scores of others are at the early stages of invasion (only recently introduced and\\/or entering a phase of rapid population growth). Management programmes must target well-established invaders, but must also give appropriate attention to emerging problems. Protocols for objectively prioritizing species in the two

J. L. Nel; D. M. Richardson; M. Rouget; T. N. Mgidi; N. Mdzeke; D. C. Le Maitre; B. W. van Wilgen; L. Schonegevel; L. Henderson; S. Neser

227

Effects of aqueous extracts of some plant species against Fusarium solani and Rhizoctonia solani in Phaseolus vulgaris plants  

Microsoft Academic Search

The antifungal activity of aqueous extracts of 22 of plant species, against the linear mycelium of Fusarium solani and Rhizoctonia solani, were tested in vitro test. All plant extracts have an antifungal activity against the two fungi except Basil, Castor beans, Chamomile and Peppermint. Aqueous extracts of Chilli, Lantana, Lemon grass and Onion seeds highly reduced the mycelial growth of

H. Abd-El-Khair; G. El-Gamal Nadia

2011-01-01

228

Effects of invasive species on plant communities: an example using submersed aquatic plants at the regional scale  

Microsoft Academic Search

Submersed aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects on the hydrological\\u000a regime, sedimentation, nutrient cycling and habitat of associated fauna. Modifications of aquatic plant communities, for example\\u000a through the introduction of invasive species, can alter these functions. In the Sacramento-San Joaquin River Delta, California,\\u000a a major invasive submersed plant, Brazilian waterweed Egeria densa,

Maria J. SantosLars; Lars W. Anderson; Susan L. Ustin

2011-01-01

229

TESTING LIFE HISTORY CORRELATES OF INVASIVENESS USING CONGENERIC PLANT SPECIES  

Microsoft Academic Search

We used three congeneric annual thistles, which vary in their ability to invade California (USA) annual grasslands, to test whether invasiveness is related to differences in life history traits. We hypothesized that populations of these summer-flowering Centaurea species must pass through a demographic gauntlet of survival and reproduction in order to persist and that the most invasive species (C. solstitialis)

John D. Gerlach; Kevin J. Rice

2003-01-01

230

Higher effect of plant species diversity on productivity in natural than artificial ecosystems  

PubMed Central

Current and expected changes in biodiversity have motivated major experiments, which reported a positive relationship between plant species diversity and primary production. As a first step in addressing this relationship, these manipulative experiments controlled as many potential confounding covariables as possible and assembled artificial ecosystems for the purpose of the experiments. As a new step in this endeavor, we asked how plant species richness relates to productivity in a natural ecosystem. Here, we report on an experiment conducted in a natural ecosystem in the Patagonian steppe, in which we assessed the biodiversity effect on primary production. Using a plant species diversity gradient generated by removing species while maintaining constant biomass, we found that aboveground net primary production increased with the number of plant species. We also found that the biodiversity effect was larger in natural than in artificial ecosystems. This result supports previous findings and also suggests that the effect of biodiversity in natural ecosystems may be much larger than currently thought.

Flombaum, Pedro; Sala, Osvaldo E.

2008-01-01

231

Uptake of gaseous nitrous acid (HONO) by several plant species  

NASA Astrophysics Data System (ADS)

Uptake of gaseous nitrous acid (HONO) by sunflower ( Heliantus annuus L. var. gigantheus), tobacco ( Nicotiana tabacum L. var. Bel W3), castor ( Rhicinus communis L. var. Carmencita), and birch ( Betula pendula L.) was studied under controlled conditions in a continuously stirred tank reactor. Exposing plants to HONO at concentrations between 60 ppt and 10 ppb led to significant uptake by the plants. The uptake was proportional to HONO concentrations and linearly related to stomatal conductivity. HONO losses at the cuticle were of minor importance. Our data imply a quick metabolism of HONO and it is concluded that the uptake of HONO by plants is only limited by diffusion of HONO through the plants stomata. Comparing results from measurements with and without plants in the chamber it is furthermore concluded that a compensation point for HONO uptake is below 20 ppt if it exists at all. Heterogeneous formation of HONO by reactions of NO 2 on the plant surfaces was either not effective or compensated by the stomatal uptake of HONO. The data of the present study imply that plant surfaces represent a sink for HONO. Therefore, it was concluded that processes on plant surfaces cannot explain HONO formation on ground surfaces as observed in field studies.

Schimang, Ralf; Folkers, Achim; Kleffmann, Jörg; Kleist, Einhard; Miebach, Marco; Wildt, Jürgen

232

Contribution of different grass species to plant-atmosphere ammonia exchange in intensively managed grassland  

Microsoft Academic Search

Species diversity in grasslands usually declines with increasing input of nitrogen from fertilizers or atmospheric nitrogen deposition. Conversely, species diversity may also impact the build-up of soil nitrogen pools. Limited information is available on how plant-atmosphere ammonia exchange is related to species diversity in grasslands. We have here investigated grass species abundance and different foliar nitrogen pools in 4-year-old intensively

M. Mattsson; B. Herrmann; S. Jones; A. Neftel; M. A. Sutton; J. K. Schjoerring

2008-01-01

233

Size-dependent species richness: trends within plant communities and across latitude  

Microsoft Academic Search

We examine how species richness and species-specific plant density (number of species and number of individuals per species, respectively) vary within community size frequency distributions and across latitude. Communities from Asia, Africa, Europe, and North, Central and South America were studied (60? 4¢N-41? 4¢S latitude) using the Gentry data base. Log-log linear stem size (diameter) frequency distributions were constructed for

Karl J. Niklas

2003-01-01

234

Species-Specific Responses to Community Density in an Unproductive Perennial Plant Community  

PubMed Central

Most studies of density dependent regulation in plants consider a single target species, but regulation may also occur at the level of the entire community. Knowing whether a community is at carrying capacity is essential for understanding its behaviour because low density plant communities may behave quite differently than their high density counterparts. Also, because the intensity of density dependence may differ considerably between species and physical environments, generalizations about its effects on community structure requires comparisons under a range of conditions. We tested if: (1) density dependent regulation occurs at the level of an entire plant community as well as within individual species; (2) the intensity (effect of increasing community density on mean plant mass) and importance (the effect of increasing density, relative to other factors, on mean plant mass) of competition increases, decreases or remains unchanged with increasing fertilization; (3) there are species-specific responses to changes in community density and productivity. In 63 1 m2 plots, we manipulated the abundance of the nine most common species by transplanting or removing them to create a series of Initial Community Densities above and below the average natural field density, such that the relative proportion of species was consistent for all densities. Plots were randomly assigned to one of three fertilizer levels. At the community level, negative density dependence of mean plant size was observed for each of the 4 years of the study and both the intensity and importance of competition increased each year. At the species level, most species' mean plant mass were negatively density dependent. Fertilizer had a significant effect only in the final year when it had a negative effect on mean plant mass. Our data demonstrate a yield-density response at the entire community-level using perennial plant species in a multi-year experiment.

Treberg, Michael A.; Turkington, Roy

2014-01-01

235

Host plant species effects on arbuscular mycorrhizal fungal communities in tallgrass prairie  

Microsoft Academic Search

Symbiotic associations between plants and arbuscular mycorrhizal (AM) fungi are ubiquitous in many herbaceous plant communities\\u000a and can have large effects on these communities and ecosystem processes. The extent of species-specificity between these plant\\u000a and fungal symbionts in nature is poorly known, yet reciprocal effects of the composition of plant and soil microbe communities\\u000a is an important assumption of recent

Ahn-Heum Eom; David C. Hartnett; G. W. T. Wilson

2000-01-01

236

Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species  

Microsoft Academic Search

.   Photoassimilates are used by plants for production of energy, as carbon skeletons and in transport of fixed carbon between\\u000a different plant organs. Many studies have been devoted to characterizing the factors that regulate photoassimilate concentrations\\u000a in different plant species. Most studies examining photoassimilate concentrations in C3 plants have focused on analyzing starch and soluble sugars. However, work presented here

David W. Chia; Wolf-Dieter Reiter; Susan I. Gibson

2000-01-01

237

Genetic diversity in widespread species is not congruent with species richness in alpine plant communities.  

PubMed

The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies. PMID:23006492

Taberlet, Pierre; Zimmermann, Niklaus E; Englisch, Thorsten; Tribsch, Andreas; Holderegger, Rolf; Alvarez, Nadir; Niklfeld, Harald; Coldea, Gheorghe; Mirek, Zbigniew; Moilanen, Atte; Ahlmer, Wolfgang; Marsan, Paolo Ajmone; Bona, Enzo; Bovio, Maurizio; Choler, Philippe; Cie?lak, El?bieta; Colli, Licia; Cristea, Vasile; Dalmas, Jean-Pierre; Frajman, Božo; Garraud, Luc; Gaudeul, Myriam; Gielly, Ludovic; Gutermann, Walter; Jogan, Nejc; Kagalo, Alexander A; Korbecka, Gra?yna; Küpfer, Philippe; Lequette, Benoît; Letz, Dominik Roman; Manel, Stéphanie; Mansion, Guilhem; Marhold, Karol; Martini, Fabrizio; Negrini, Riccardo; Niño, Fernando; Paun, Ovidiu; Pellecchia, Marco; Perico, Giovanni; Pi?ko?-Mirkowa, Halina; Prosser, Filippo; Pu?ca?, Mihai; Ronikier, Micha?; Scheuerer, Martin; Schneeweiss, Gerald M; Schönswetter, Peter; Schratt-Ehrendorfer, Luise; Schüpfer, Fanny; Selvaggi, Alberto; Steinmann, Katharina; Thiel-Egenter, Conny; van Loo, Marcela; Winkler, Manuela; Wohlgemuth, Thomas; Wraber, Tone; Gugerli, Felix; Vellend, Mark

2012-12-01

238

Individual-based ant-plant networks: diurnal-nocturnal structure and species-area relationship.  

PubMed

Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants' composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this "night-turnover" suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences. PMID:24918750

Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A Q; Silva, Mara S A; Vieira, Marisa C L; Izzo, Thiago J; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

2014-01-01

239

Individual-Based Ant-Plant Networks: Diurnal-Nocturnal Structure and Species-Area Relationship  

PubMed Central

Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants’ composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this “night-turnover” suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences.

Dattilo, Wesley; Fagundes, Roberth; Gurka, Carlos A. Q.; Silva, Mara S. A.; Vieira, Marisa C. L.; Izzo, Thiago J.; Diaz-Castelazo, Cecilia; Del-Claro, Kleber; Rico-Gray, Victor

2014-01-01

240

Seed banks and seed population dynamics of halophytes  

Microsoft Academic Search

In this review I will describe the importance of seed banks and thepopulation dynamics of seeds on the distribution of species in salinehabitats. The main questions being examined in this review include: 1.Does the seed bank represent the flora of the entire salinity gradient or isit restricted to the species in each zonal community? 2. Is the size andspecies composition

Irwin A. Ungar

2001-01-01

241

Rubisco specificity factor tends to be larger in plant species from drier habitats and in species with persistent leaves  

Microsoft Academic Search

The specificity factor of Rubisco is a measure of the relative capacities of the enzyme to catalyse carboxylation and oxy- genation of ribulose 1,5-bisphosphate and hence to control the relative rates of photosynthetic carbon assimilation and photorespiration. Specificity factors of purified Rubisco from 24 species of C3 plants found in diverse habitats with a wide range of environmental growth limitations

JERONI GALMES; JAUME FLEXAS; ALFRED J. KEYS; JOSEP CIFRE; ROWAN A. C. MITCHELL; PIPPA J. MADGWICK; RICHARD P. HASLAM; HIPOLITO MEDRANO; MARTIN A. J. PARRY

2005-01-01

242

Effects of Plant Species on Nutrient Cycling in Healthlands.  

National Technical Information Service (NTIS)

Contents: Decomposition and nutrient dynamics of litters and roots from heathlands; Species and site differences in the decomposition of litters and roots from wet heathlands. Carbon, nitrogen, and phosphorus dynamics in decomposing litters and roots in d...

M. van Vuuren

1992-01-01

243

Critical review on medicinally potent plant species: Gloriosa superba.  

PubMed

Gloriosa superba L. is a perennial climber and is used as an ayurvedic medicinal herb to cure diseases in various parts of Africa and Southeast Asia. The plant was under threatened category due to its imprudent harvesting from wild as it is extensively used by medicinal industries for its colchicine content. It also faces a low seed set problem, but due to its industrial demand it is now under cultivation. The plant is used to cure arthritis, gout, rheumatism, inflammation, ulcers, bleeding piles, skin diseases, leprosy, impotency, snakebites, etc. Various compounds have been isolated from the plant parts mainly tubers and seeds, viz colchicine, colchicoside (its semi-synthetic derivative - thiocolchicoside), superbine, gloriosine, lumicolchicine, 3-demethyl-N-deformyl-N-deacetylcolchicine, 3-demethylcolchicine, N-formyl deacetylcolchicine. In the present review, we have summarized the information concerning the occurrence, botanical description, ethanopharmacology, medicinal uses, biological activities and toxicological studies on this plant. PMID:21059382

Jana, Sonali; Shekhawat, G S

2011-04-01

244

Habitat types on the Hanford Site: Wildlife and plant species of concern  

SciTech Connect

The objective of this report is to provide a comprehensive source of the best available information on Hanford Site sensitive and critical habitats and plants and animals of importance or special status. In this report, sensitive habitats include areas known to be used by threatened, endangered, or sensitive plant or animal species, wetlands, preserves and refuges, and other sensitive habitats outlined in the Hanford Site Baseline Risk Assessment Methodology. Potentially important species for risk assessment and species of special concern with regard to their status as threatened, endangered, or sensitive are described, and potential habitats for these species identified.

Downs, J.L.; Rickard, W.H.; Brandt, C.A. [and others

1993-12-01

245

Optimum-transformation of plant species cover-abundance values  

Microsoft Academic Search

Most of the methods used in the multivariate analysis of data on vegetation and environment, or transformations implied in such methods, put disproportionate emphasis on species with a relatively wide ecological amplitude occurring with relatively high cover-abundance values, and\\/or rare species. This problem can be overcome to some extent by reducing the cover-abundance values to presence-absence data, but this means

Vera Noest; Eddy van der Maarel; Frank van der Meulen; Dick van der Laan

1989-01-01

246

Germination characteristics of six plant species growing on the Hanford Site. [Disturbed land revegetation feasibility studies  

SciTech Connect

Six plant species (Siberian and thickspike wheatgrass, cheatgrass, sand dropseed, Indian ricegrass, and Russian thistle) found on the Hanford Site were studied as part of an investigation into the revegetation of disturbed areas. Germination response to three environmental parameters (soil moisture, soil temperature, and planting depth) were measured. Results indicated that when a polyethylene glycol solution was used to control the osmotic potential of the imbibition media, no significant decrease in germination rate occurred down to -3.0 bars. However, below -7.0 bars all species experienced a decrease in germination. When germinated in soil, all species except Russian thistle exhibited a significant decrease in germination rate at -0.3 bars. Russian thistle was the only species tested that exhibited germination at a soil temperature of 1/sup 0/C. All species gave optimum germination at temperatures between 10 and 15/sup 0/C. Thickspike wheatgrass was the only species tested which was able to germinate and emerge from a planting depth of greater than 2 inches. If supplemental moisture is provided, a shallow planting would be advisable for those species tested. If not overcome by pretreatment prior to planting, seed dormancy may be a significant factor which will reduce the germination potential of some species tested.

Cox, G.R.; Kirkham, R.R.; Cline, J.F.

1980-03-01

247

Areas of increasing agricultural abandonment overlap the distribution of previously common, currently threatened plant species.  

PubMed

Human-driven land-use changes increasingly threaten biodiversity. In agricultural ecosystems, abandonment of former farmlands constitutes a major land-use shift. We examined the relationships between areas in which agriculture has been abandoned and the distribution records of threatened plant species across Japan. We selected 23 plant species that are currently identified as threatened but were previously common in the country as indicators of threatened plant species. The areas of abandoned farmlands within the distribution ranges of the indicator species were significantly larger than the proportion of abandoned farmland area across the whole country. Also, abandoned farmland areas were positively correlated with the occurrence of indicator species. Therefore, sections of agricultural landscape that are increasingly becoming abandoned and the distribution ranges of indicator species overlapped. These results suggest that abandoned farmland areas contain degraded or preferred habitats of threatened plant species. We propose that areas experiencing increased abandonment of farmland can be divided into at least two categories: those that threaten the existence of threatened species and those that provide habitats for these threatened species. PMID:24260328

Osawa, Takeshi; Kohyama, Kazunori; Mitsuhashi, Hiromune

2013-01-01

248

Areas of Increasing Agricultural Abandonment Overlap the Distribution of Previously Common, Currently Threatened Plant Species  

PubMed Central

Human-driven land-use changes increasingly threaten biodiversity. In agricultural ecosystems, abandonment of former farmlands constitutes a major land-use shift. We examined the relationships between areas in which agriculture has been abandoned and the distribution records of threatened plant species across Japan. We selected 23 plant species that are currently identified as threatened but were previously common in the country as indicators of threatened plant species. The areas of abandoned farmlands within the distribution ranges of the indicator species were significantly larger than the proportion of abandoned farmland area across the whole country. Also, abandoned farmland areas were positively correlated with the occurrence of indicator species. Therefore, sections of agricultural landscape that are increasingly becoming abandoned and the distribution ranges of indicator species overlapped. These results suggest that abandoned farmland areas contain degraded or preferred habitats of threatened plant species. We propose that areas experiencing increased abandonment of farmland can be divided into at least two categories: those that threaten the existence of threatened species and those that provide habitats for these threatened species.

Osawa, Takeshi; Kohyama, Kazunori; Mitsuhashi, Hiromune

2013-01-01

249

Studies on Halophytes and Salinity Problems in Mediterranean Agriculture  

Microsoft Academic Search

The sustainability of irrigation with saline waters can only be achieved if the appropriate management of the whole soil–water–plant–atmosphere\\u000a system is considered. In the present paper is argued that existing guidelines on plant tolerance to salinity and leaching\\u000a requirement supply just roughly approximate, sometimes misleading indications for a correct management.\\u000a \\u000a Results of previous experiments and demonstration activities with woody and

A. Belligno; V. Sardo

250

Placing Animals and Plants on the List of Endangered and Threatened Species.  

National Technical Information Service (NTIS)

The report is a written summary of source information regarding the legislative protection currently being provided to wild plant species in the various states of the United States. This document should be treated as a working document that will periodica...

A. Farnsworth B. Holmes

1981-01-01

251

Development of Methods of Nitrogen Management for Woody Ornamental Species in Landscape Plantings.  

National Technical Information Service (NTIS)

The primary purpose of this experiment was to evaluate the effects of fertilizer nitrogen source on survival and growth of several woody ornamental species used in highway plantings. Even without nitrogen fertilization, very satisfactory growth occurred. ...

J. F. Power H. W. Sengpiel

1977-01-01

252

Identification and Management of Multiple Threats to Rare and Endangered Plant Species.  

National Technical Information Service (NTIS)

We investigated effects of deer, nutrient addition, and presence of non-native plants, earthworms and a root-weevil on demography of rare understory species (Aristolochia serpentaria, Agrimonia rostellata, Carex retroflexa, and Trillium erectum) using a c...

A. Davalos B. Blossey E. Cooch V. Nuzzo

2013-01-01

253

ACCURACY ASSESSMENTS OF AIRBORNE HYSPERSPECTRAL DATA FOR MAPPING OPPORTUNISTIC PLANT SPECIES IN FRESHWATER COASTAL WETLANDS  

EPA Science Inventory

Airbome hyperspectral data were used to detect dense patches of Phragmites australis, a native opportunist plant species, at the Pointe Mouillee coastal wetland complex (Wayne and Monroe Counties, Michigan). This study provides initial results from one of thirteen coastal wetland...

254

AN ECOLOGICAL ASSESSMENT OF OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS USING AIRBORNE HYPERSPECTRAL DATE  

EPA Science Inventory

Airbome hyperspectral data were used to detect dense patches of Phragmites australis, a native opportunist plant species, at the Pointe Mouillee coastal wetland complex (Wayne and Monroe Counties, Michigan). This study provides initial results from one of thirteen coastal wetland...

255

Spatial and temporal variation in natural enemy assemblages on Maryland native plant species.  

PubMed

Habitat manipulation is a branch of conservation biological control in which vegetation complexity and diversity are increased in managed landscapes to provide food and other resources for arthropod natural enemies. This is often achieved by maintaining noncrop plant material such as flowering strips and beetle banks that provide natural enemies with nectar and pollen, alternative prey, shelter from disturbance, and overwintering sites. In most cases, plant material used in habitat manipulation programs is not native to the area in which it is planted. Using native plant species in conservation biological control could serve a dual function of suppressing pest arthropod outbreaks and promoting other valuable ecosystem services associated with native plant communities. We evaluated 10 plant species native to Maryland for their attractiveness to foliar and ground-dwelling natural enemies. Plants that showed particular promise were Monarda punctata, Pycnanthemum tenuifolium, and Eupatorium hyssopifolium, which generally harbored the greatest abundance of foliar predators and parasitoids, although abundance varied over time. Among ground-dwelling natural enemies, total predator and parasitoid abundance differed between plant species, but carabid and spider abundance did not. Matching certain plant species and their allied natural enemies with specific pest complexes may be enhanced by identifying the composition of natural enemy assemblages at different times of year and in both foliar and ground habitat strata. PMID:18419920

Frank, Steven D; Shrewsbury, Paula M; Esiekpe, Okemeteri

2008-04-01

256

Plant compositional constituents affecting between-plant and animal species prediction of forage intake.  

PubMed

The purpose of the study was to identify plant compositional constituents that influence forage intake. Emphasis was put on the ratio in vitro digestibility of organic matter (IVDOM):NDF because preliminary work with cattle and a limited number of forages showed the ratio to account for more variation in intake than either IVDOM or NDF alone. The compositional constituents were tested in intake prediction models using local and published data (n = 302) on grass pastures, silages, hays, straws, legumes, grass-legume mixtures, and shrubs ingested by both browsing and grass-eating ruminants (goats, red deer, impala, blesbok, sheep, cattle, and blue wildebeest). In the local experiments, esophageally fistulated and fecal bag-harnessed animals were used to collect representative grazed forage samples from pastures and to determine OM excreted, respectively. Forage intake was calculated as OM excreted divided by (1-IVDOM). Intake of silages, hays, and straws was measured indoors in digestibility trials. Intakes among species were compared after scaling for size by BW raised to the power of .9. Major contributors to the variation in forage intake were ash, hemicellulose, IVDOM:NDF, ADL, and the interaction between DM content and, respectively, ash, N, and ADL. High tannin/phenol concentrations proved limiting to intake. The ratio of IVDOM:NDF accounted for 67% of the variation in forage intake if data for which the other constituents had an effect were omitted, and the equation, OMI, g.kg BW-.9.d-1 = 70-97e-.975(IVDOM:NDF), predicted intake across all forages and ruminant species with a Sy.x of 5.3 g.kg BW-.9.d-1 (CV = 15%). The ratio of IVDOM:NDF should be valuable as a relatively inexpensive and rapid method to screen forages and cultivars. PMID:8567482

Meissner, H H; Paulsmeier, D V

1995-08-01

257

Variation in habitat suitability does not always relate to variation in species' plant functional traits  

PubMed Central

Habitat suitability models, which relate species occurrences to environmental variables, are assumed to predict suitable conditions for a given species. If these models are reliable, they should relate to change in plant growth and function. In this paper, we ask the question whether habitat suitability models are able to predict variation in plant functional traits, often assumed to be a good surrogate for a species' overall health and vigour. Using a thorough sampling design, we show a tight link between variation in plant functional traits and habitat suitability for some species, but not for others. Our contrasting results pave the way towards a better understanding of how species cope with varying habitat conditions and demonstrate that habitat suitability models can provide meaningful descriptions of the functional niche in some cases, but not in others.

Thuiller, Wilfried; Albert, Cecile H.; Dubuis, Anne; Randin, Christophe; Guisan, Antoine

2010-01-01

258

Species invasion alters local adaptation to soil communities in a native plant.  

PubMed

Plant populations are often adapted to their local conditions, including abiotic factors as well as the biotic communities with which they interact. Soil communities, in particular, have strong effects on both the ecology and evolution of plant populations. Many invasive plant species alter the ecological relationships between native plants and soil communities; however, whether invaders also alter the evolutionary dynamics between native plants and soils is less well known. Here I show that populations of a native annual, Pilea pumila, shift from being maladapted to adapted to their local soil community with increasing history of invasion by Alliaria petiolata, an invader known to alter microbial communities. Additionally, native populations showed a signal of adaptation to soils of particular invasion stages, independent of local coevolutionary dynamics. These results suggest that invasive species affect not only the ecological, but also the evolutionary relationships of native species. PMID:23600238

Lankau, Richard A

2013-01-01

259

Stability of Se species in plant extracts rich in phenolic substances  

Microsoft Academic Search

Since there is growing awareness of the strong dependence of the antioxidative function of selenium (Se) upon its chemical\\u000a form, the stability of Se species during sample preparation is an important factor in obtaining qualitative and quantitative\\u000a results. Many plant samples are rich in phenolic compounds (antioxidants), but data about their effect on specific Se species\\u000a in extracts of plant

Petra Cuderman; Vekoslava Stibilj

2010-01-01

260

Differential effects of elevated ultraviolet-B radiation on plant species of a dune grassland ecosystem  

Microsoft Academic Search

In a greenhouse study, plants of three monocotyledonous and five dicotyledonous species, which occur in a Dutch dune grassland, were exposed to four levels of ultraviolet-B (UV-B) radiation. UV-B levels simulated up to 30% reduction of the stratospheric ozone column during summertime in The Netherlands. Six of the plant species studied in the greenhouse were also exposed to enhanced UV-B

Marcel Tosserams; Erwin Magendans; Jelte Rozema

1997-01-01

261

Plant,Animal, and Microbe Invasive Species in the United States and World  

Microsoft Academic Search

Approximately 50,000 plant, animal, and microbe invasive species are present in the United States, and an estimated 500,000\\u000a plant, animal, and microbe invasive species have invaded other nations of the world. Immediately, it should be pointed out\\u000a that the US and world agriculture depend on introduced food crops and livestock.Approximately 99 % of all crops and livestock\\u000a in all nations

David Pimentel; Marcia Pimentel; Anne Wilson

262

Laser-induced fluorescence of green plants. I - A technique for the remote detection of plant stress and species differentiation  

NASA Technical Reports Server (NTRS)

The laser-induced fluorescence (LIF) of green plants was evaluated as a means of remotely detecting plant stress and determining plant type. Corn and soybeans were used as representatives of monocots and dicots, respectively, in these studies. The fluorescence spectra of several plant pigments was excited with a nitrogen laser emitting at 337 nm. Intact leaves from corn and soybeans also fluoresced using the nitrogen laser. The two plant species exhibited fluorescence spectra which had three maxima in common at 440, 690, and 740 nm. However, the relative intensities of these maxima were distinctly different for the two species. Soybeans had an additional slight maxima at 525 nm. Potassium deficiency in corn caused an increase in fluorescence at 690 and 740 nm. Simulated water stress in soybeans resulted in increased fluorescence at 440, 525, 690, and 740 nm. The inhibition of photosynthesis in soybeans by 3-(3-4-dichlorophenyl)-1-1-dimethyl urea (DCMU) gave incresed fluorescence primarily at 690 and 740 nm. Chlorosis as occurring in senescent soybean leaves caused a decrease in fluorescence at 690 and 740 nm. These studies indicate that LIF measurements of plants offer the potential for remotely detecting certain types of stress condition and also for differentiating plant species.

Chappelle, E. W.; Wood, F. M., Jr.; Mcmurtrey, J. E., III; Newcomb, W. W.

1984-01-01

263

Photosynthetic and respiratory activity in germfree higher plant species  

NASA Technical Reports Server (NTRS)

Equipment developed for the study of gas exchange in germfree plants is described. The equipment includes a gas exchange chamber to house the plant under study, a gas feed assembly to introduce and remove gas from the chamber, and a clinostat to rotate the apparatus. Fluorescent and incandescent lights are used to illuminate the chamber and a sealed plastic barrier is used to isolate the potting soil from the chamber atmosphere. The gas outflow from the chamber can be diverted to an infrared CO2 analyzer. The performance of the system was evaluated.

1976-01-01

264

Species delimitation and phylogeny of a New Zealand plant species radiation  

PubMed Central

Background Delimiting species boundaries and reconstructing the evolutionary relationships of late Tertiary and Quaternary species radiations is difficult. One recent approach emphasizes the use of genome-wide molecular markers, such as amplified fragment length polymorphisms (AFLPs) and single nucleotide polymorphisms (SNPs), to identify distinct metapopulation lineages as taxonomic species. Here we investigate the properties of AFLP data, and the usefulness of tree-based and non-tree-based clustering methods to delimit species and reconstruct evolutionary relationships among high-elevation Ourisia species (Plantaginaceae) in the New Zealand archipelago. Results New Zealand Ourisia are shown to comprise a geologically recent species radiation based on molecular dating analyses of ITS sequences (0.4–1.3 MY). Supernetwork analyses indicate that separate tree-based clustering analyses of four independent AFLP primer combinations and 193 individuals of Ourisia produced similar trees. When combined and analysed using tree building methods, 15 distinct metapopulations could be identified. These clusters corresponded very closely to species and subspecies identified on the basis of diagnostic morphological characters. In contrast, Structure and PCO-MC analyses of the same data identified a maximum of 12 and 8 metapopulations, respectively. All approaches resolved a large-leaved group and a small-leaved group, as well as a lineage of three alpine species within the small-leaved group. We were unable to further resolve relationships within these groups as corrected and uncorrected distances derived from AFLP profiles had limited tree-like properties. Conclusion Ourisia radiated into a range of alpine and subalpine habitats in New Zealand during the Pleistocene, resulting in 13 morphologically and ecologically distinct species, including one reinstated from subspecies rank. Analyses of AFLP identified distinct metapopulations consistent with morphological characters allowing species boundaries to be delimited in Ourisia. Importantly, Structure analyses suggest some degree of admixture with most species, which may also explain why the AFLP data do not exhibit sufficient tree-like properties necessary for reconstructing some species relationships. We discuss this feature and highlight the importance of improving models for phylogenetic analyses of species radiations using AFLP and SNP data.

Meudt, Heidi M; Lockhart, Peter J; Bryant, David

2009-01-01

265

Validation of the ITS2 Region as a Novel DNA Barcode for Identifying Medicinal Plant Species  

PubMed Central

Background The plant working group of the Consortium for the Barcode of Life recommended the two-locus combination of rbcL + matK as the plant barcode, yet the combination was shown to successfully discriminate among 907 samples from 550 species at the species level with a probability of 72%. The group admits that the two-locus barcode is far from perfect due to the low identification rate, and the search is not over. Methodology/Principal Findings Here, we compared seven candidate DNA barcodes (psbA-trnH, matK, rbcL, rpoC1, ycf5, ITS2, and ITS) from medicinal plant species. Our ranking criteria included PCR amplification efficiency, differential intra- and inter-specific divergences, and the DNA barcoding gap. Our data suggest that the second internal transcribed spacer (ITS2) of nuclear ribosomal DNA represents the most suitable region for DNA barcoding applications. Furthermore, we tested the discrimination ability of ITS2 in more than 6600 plant samples belonging to 4800 species from 753 distinct genera and found that the rate of successful identification with the ITS2 was 92.7% at the species level. Conclusions The ITS2 region can be potentially used as a standard DNA barcode to identify medicinal plants and their closely related species. We also propose that ITS2 can serve as a novel universal barcode for the identification of a broader range of plant taxa.

Chen, Shilin; Yao, Hui; Han, Jianping; Liu, Chang; Song, Jingyuan; Shi, Linchun; Zhu, Yingjie; Ma, Xinye; Gao, Ting; Pang, Xiaohui; Luo, Kun; Li, Ying; Li, Xiwen; Jia, Xiaocheng; Lin, Yulin; Leon, Christine

2010-01-01

266

Subtropical reservoir shorelines have reduced plant species and functional richness compared with adjacent riparian wetlands  

NASA Astrophysics Data System (ADS)

Dam construction has large negative effects on biodiversity in river and riparian ecosystems worldwide. This study aimed to determine whether reservoir shorelines had lower plant species diversity and functional diversity than unregulated or lightly regulated riparian wetlands and to examine the responses of plant diversity and functional traits to reservoir shoreline environmental gradients. We surveyed 146, 44, and 67 plots on reservoir shorelines and in mainstem and tributary riparian wetlands, respectively, in a subtropical river-reservoir system. Species richness, functional richness, evenness, and divergence were calculated to reflect the species and functional diversity of plant communities. Environmental factors including elevation above water level, slope, landform type, substrate, disturbance, and cover were measured. The results showed that both species and functional richness were significantly lower on reservoir shorelines than in riparian wetlands. The relative species number of clonal plants and relative cover of annual plants were both negatively related to slope and elevation. Structural equation modeling and other statistical analyses indicated that most environmental factors had significant effects on species and functional richness on reservoir shorelines but had no significant effect on functional evenness and divergence. Our findings suggest that reservoir shoreline wetlands formed by damming rivers and inundating pre-existing riparian wetlands can be a biodiversity coldspot in regulated rivers at the plot level. Topographic factors are important in determining the plant diversity and vegetation establishment on reservoir shorelines in the Yangtze River basin.

Liu, Wenzhi; Liu, Guihua; Liu, Hui; Song, Yu; Zhang, Quanfa

2013-12-01

267

Rapid Plant Identification Using Species- and Group-Specific Primers Targeting Chloroplast DNA  

PubMed Central

Plant identification is challenging when no morphologically assignable parts are available. There is a lack of broadly applicable methods for identifying plants in this situation, for example when roots grow in mixture and for decayed or semi-digested plant material. These difficulties have also impeded the progress made in ecological disciplines such as soil- and trophic ecology. Here, a PCR-based approach is presented which allows identifying a variety of plant taxa commonly occurring in Central European agricultural land. Based on the trnT-F cpDNA region, PCR assays were developed to identify two plant families (Poaceae and Apiaceae), the genera Trifolium and Plantago, and nine plant species: Achillea millefolium, Fagopyrum esculentum, Lolium perenne, Lupinus angustifolius, Phaseolus coccineus, Sinapis alba, Taraxacum officinale, Triticum aestivum, and Zea mays. These assays allowed identification of plants based on size-specific amplicons ranging from 116 bp to 381 bp. Their specificity and sensitivity was consistently high, enabling the detection of small amounts of plant DNA, for example, in decaying plant material and in the intestine or faeces of herbivores. To increase the efficacy of identifying plant species from large number of samples, specific primers were combined in multiplex PCRs, allowing screening for multiple species within a single reaction. The molecular assays outlined here will be applicable manifold, such as for root- and leaf litter identification, botanical trace evidence, and the analysis of herbivory.

Staudacher, Karin; Schallhart, Nikolaus; Mitterrutzner, Evi; Steiner, Eva-Maria; Thalinger, Bettina; Traugott, Michael

2012-01-01

268

Uptake Kinetics of Arsenic Species in Rice Plants  

PubMed Central

Arsenic (As) finds its way into soils used for rice (Oryza sativa) cultivation through polluted irrigation water, and through historic contamination with As-based pesticides. As is known to be present as a number of chemical species in such soils, so we wished to investigate how these species were accumulated by rice. As species found in soil solution from a greenhouse experiment where rice was irrigated with arsenate contaminated water were arsenite, arsenate, dimethylarsinic acid, and monomethylarsonic acid. The short-term uptake kinetics for these four As species were determined in 7-d-old excised rice roots. High-affinity uptake (0–0.0532 mm) for arsenite and arsenate with eight rice varieties, covering two growing seasons, rice var. Boro (dry season) and rice var. Aman (wet season), showed that uptake of both arsenite and arsenate by Boro varieties was less than that of Aman varieties. Arsenite uptake was active, and was taken up at approximately the same rate as arsenate. Greater uptake of arsenite, compared with arsenate, was found at higher substrate concentration (low-affinity uptake system). Competitive inhibition of uptake with phosphate showed that arsenite and arsenate were taken up by different uptake systems because arsenate uptake was strongly suppressed in the presence of phosphate, whereas arsenite transport was not affected by phosphate. At a slow rate, there was a hyperbolic uptake of monomethylarsonic acid, and limited uptake of dimethylarsinic acid.

Abedin, Mohammed Joinal; Feldmann, Jorg; Meharg, Andy A.

2002-01-01

269

Uncertainty in Comparative Risk Analysis for Threatened Australian Plant Species  

Microsoft Academic Search

Australian state and federal agencies use a broad range of methods for setting conservation priorities for species at risk. Some of these are based on rule sets developed by the Interna- tional Union for the Conservation of Nature, while others use point scoring protocols to assess threat. All of them ignore uncertainty in the data. In this study, we assessed

Mark A. Burgman; David A. Keith; Terry V. Walshe

1999-01-01

270

Phylloepiphytic interaction between bacteria and different plant species in a tropical agricultural system.  

PubMed

Plant surfaces are a favourable niche for bacterial establishment, and hypothetically, plant species differ in their capacity to harbour epiphytic bacterial communities. This study was conducted to evaluate and describe the structural relationship of a bacterial community at the phyllosphere level with different plant species in a tropical ecosystem. Leaf blades of 47 plant species distributed in 27 botanical families were collected on a typical small Brazilian farm and prepared for observation under light and scanning electron microscopy. Naturally occurring bacteria were the most abundant settlers of the phylloplane, followed by fungal spore or hyphae. All plant species studied were colonized by phylloepiphytic bacteria, which were observed as solitary cells, microcolonies, and biofilms. However, independent of the family, the plant species differed in the pattern of phyllosphere colonization, as reflected in bacteria frequency and presence or absence of anatomical features that would favour the association. The phylloepiphytic bacteria were preferentially established on the following sites: epidermal cell wall junctions, glandular and nonglandular trichomes, veins, stomata, and epidermal cell wall surface. Profuse bacteria and fungi colonization was observed, at a level that was at least comparable with temperate regions. Interestingly, fungi seemed to alter the bacteria colonization pattern, most probably by microenvironmental modifications. The trichome type and density as well as the presence of epicuticular wax on the leaf blade surface seemed to be the most determinant anatomical features for the pattern of phyllosphere colonization. The presence of trichomes has a favourable, and epicuticular wax an unfavourable influence on the plant-bacteria interaction. PMID:18997848

Baldotto, Lílian Estrela Borges; Olivares, Fábio Lopes

2008-11-01

271

Critical review on medicinally potent plant species: Gloriosa superba  

Microsoft Academic Search

Gloriosa superba L. is a perennial climber and is used as an ayurvedic medicinal herb to cure diseases in various parts of Africa and Southeast Asia. The plant was under threatened category due to its imprudent harvesting from wild as it is extensively used by medicinal industries for its colchicine content. It also faces a low seed set problem, but

Sonali Jana; G. S. Shekhawat

2011-01-01

272

The Edaphic Factor in the Origin of Plant Species  

Microsoft Academic Search

Although speciation has been a central focus in evolutionary biology for more than a century, there are very few case studies where we have a good understanding of the exact forces that may have acted in the diversification of a group of organisms. In order to examine such forces, botanists have often focused on closely related plants that are found

Nishanta Rajakaruna

2004-01-01

273

Survival of Plant Species as a Function of Salinity and Slope Position  

Microsoft Academic Search

An experiment was conducted during 1995-1997 at Truscott Brine Lake, Truscott, TX to determine whether any of 38 salt tolerant plant species could survive salt conditions at Truscott Brine Lake and tolerate the summer heat and winter cold of northwest Texas. Little is known regarding survival and growth of species native to salt marsh conditions of southern United States coastal

David G. Bordovsky; Manilal Choudhary; R. James Ansley

274

Dry Season Decomposition of Leaf Litter from Five Common Plant Species of West Africa  

Microsoft Academic Search

The rates of decomposition of litter from five plant species common to West Africa namely: Chromolaena odorata (Siam weed), Anacardium occidentale (cashew), Acioa batteri, Imperata cylindrica (spear grass) and Pentaclethra macrophylla (oil bean) were investigated in the laboratory and the field during the dry season using respiration and litter bag techniques.There were significant differences (P< 0.05) amongst the species in

N. N. Agbim

1987-01-01

275

Assessing the risk of Glyphosate to native plants and weedy Brassicaceae species of North Dakota  

EPA Science Inventory

This study was conducted to determine the ecological risk to native plants and weedy Brassicaceae species which may be growing in areas affected by off target movement of glyphosate applied to glyphosate-resistant canola (Brassica napus). Ten native grass and forb species were ...

276

Characteristics of heavy metal uptake by plant species with potential for phytoremediation and phytomining  

Microsoft Academic Search

Genetically transformed hairy root cultures were established for a range of plant species and applied in studies of growth and accumulation of heavy metals. Experiments were conducted using liquid nutrient medium containing elevated concentrations of Ni, Cd or Cu. Hairy roots of three hyperaccumulator species were tested for Ni uptake, of these, Alyssum bertolonii accumulated the highest Ni contents in

T. V. Nedelkoska; P. M. Doran

2000-01-01

277

Students' Perception of Plant and Animal Species: A Case Study from Rural Argentina  

ERIC Educational Resources Information Center

Exotic species seriously affect local biodiversity in Argentina. This article investigates how students in San Juan province perceive native and exotic species. With the help of a written questionnaire, 865 students (9-17 years old) were asked to name the plant and animal they liked most, disliked most, and perceived as most useful, and to name…

Nates, Juliana; Campos, Claudia; Lindemann-Matthies, Petra

2010-01-01

278

Extinction and Introgression in a Community of Partially Cross?Fertile Plant Species  

Microsoft Academic Search

We develop a model to study the demography and ge- netics of an encounter between two partially cross-fertile plant spe- cies. We assume prezygotic reproductive isolation between the spe- cies, a common situation when the species differ by their phenology or floral traits that cause assortative mating. Three outcomes are possible: coexistence of both species with minimal introgression; domination by

Frédéric Austerlitz

2002-01-01

279

Endangered Plant Species of the Nevada Test Site, Ash Meadows, and Central-Southern Nevada.  

National Technical Information Service (NTIS)

A total of 15 vascular plant taxa, currently appearing on the endangered species list, occur in southern Nye County, Nevada, and/or adjacent Inyo County, California. It is the purpose of this report to record in detail the locations of the plant collectio...

J. C. Beatley

1977-01-01

280

Species Composition of Bacterial Communities Influences Attraction of Mosquitoes to Experimental Plant Infusions  

Microsoft Academic Search

In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito species, which are global vectors of dengue viruses. In laboratory experiments, gravid females

Loganathan Ponnusamy; Dawn M. Wesson; Consuelo Arellano; Coby Schal; Charles S. Apperson

2009-01-01

281

Simulating direct and indirect effects of climatic changes on rare perennial plant species in fragmented landscapes  

Microsoft Academic Search

Question: How does climate change influence plant species population dynamics, their time to extinction, and proportion of occupied habitats in a fragmented landscape? Location: Germany and Central European lowland. Methods: We apply a mechanistic general simulation model to test the response of plant functional types to direct and indirect effects of climate change. Three functional types were chosen to represent

K. Korner; A. C. Treydte; M. Burkart; F. Jeltsch

2010-01-01

282

Review of Plant Taxa for Listing as Endangered or Threatened Species: Compilation by State.  

National Technical Information Service (NTIS)

On December 15, 1980, the US Fish and Wildlife Service, Department of the Interior, published a notice of review entitled Endangered and Threatened Wildlife and Plants: Review of Plant Taxa for Listing as Endangered or Threatened Species (45FR82480-82569)...

J. Nagy C. E. Calef

1980-01-01

283

Zinc Accumulation in Plant Species Indigenous to a Portuguese Polluted Site: Relation with Soil Contamination  

Microsoft Academic Search

The levels of zinc accumulated by roots, stems, and leaves of two plant species, Rubus ulmifoliusand Phragmites australis, indigenous to the banks of a stream in a Portuguese contaminated site were inves- tigated in field conditions. R. ulmifolius, a plant for which studies on phytoremediation potential are scarce, dominated on the right side of the stream, while P. australis proliferated

Ana P. G. C. Marques; Antonio O. S. S. Rangel; Paula M. L. Castro

2007-01-01

284

The potential of Thai indigenous plant species for the phytoremediation of arsenic contaminated land  

Microsoft Academic Search

To assess the potential of the native plant species for phytoremediation, plant and soil samples were collected from two areas in Thailand that have histories of arsenic pollution from mine tailings. The areas were the Ron Phibun District (Nakorn Si Thammarat province) and Bannang Sata District (Yala province), and samples were taken in 1998 and 1999 and analysed for total

P Visoottiviseth; K Francesconi; W Sridokchan

2002-01-01

285

Antioxidant activities and polyphenolic contents of fifteen selected plant species from the Amazonian region  

Microsoft Academic Search

The polyphenolic compound content has been determined in 15 Amazonian plant species (leaves, bark, stems, fruits, and seeds) used in folk medicine, using two complementary spectrophotometric methods. In addition, the antioxidant activity of the corresponding plant extracts has been determined by TEAC (trolox equivalent antioxidant capacity) and ORACFluorescein (oxygen radical antioxidant capacity using fluorescein as fluorescent probe) assays to identify

E. M. Silva; J. N. S. Souza; H. Rogez; J. F. Rees; Y. Larondelle

2007-01-01

286

SPATIO-TEMPORAL EFFECTS ON ASSOCIATION OF PLANT SPECIES IN SOONE VALLEY OF PAKISTAN  

Microsoft Academic Search

Six ecologically diverse study sites viz., Khabeki, Khoora, Dape Sharif, Anga, Knotti Garden and Jallar were selected mainly on the basis of differences in their environmental attributes especially variations in elevation, slope, aspect, altitude, topography, soil composition, habitat, vegetation type and plant community. The available plant species at selected sites were enlisted. The ecological data was recorded during all the

IFTIKHAR AHMAD; MUMTAZ HUSSAIN; MUHAMMAD SAJID; AQEEL AHMAD; MANSOOR HAMEED

2008-01-01

287

Georeferencing and Species Distribution Modelling of Invasive Plants in the State of Florida, USA  

Microsoft Academic Search

Invasive exotic plants have wide ranging impacts. They contribute to the decline of native plant species (Mack et al. 2000; Hulme 2003; Collingham et al. 2000), negatively impact hydrology of certain habitats (Parker et al. 1999; Graf 1978 in Hobbs and Humphries 1995), and create problems for wildlife by altering vegetation structure and food sources (Mack et al. 2000; Hulme

Sarah Jean Braun

2007-01-01

288

VARIATION IN GRAZING TOLERANCE AMONG THREE TALLGRASS PRAIRIE PLANT SPECIES1  

Microsoft Academic Search

Three tallgrass prairie plant species, two common perennial forbs (Artemisia ludoviciana and Aster ericoides (Asteraceae)) and a dominant C4 perennial grass (Sorghastrum nutans) were studied under field and greenhouse conditions to evaluate interspecific variation in grazing tolerance (compensatory growth capacity). Adaptation to ungulate grazing was also assessed by comparing defoliation responses of plants from populations with a 25-yr history of

SAID A. DAMHOUREYEH; DAVID C. HARTNETT

289

Shifts in species richness, herbivore specialization, and plant resistance along elevation gradients.  

PubMed

Environmental gradients have been postulated to generate patterns of diversity and diet specialization, in which more stable environments, such as tropical regions, should promote higher diversity and specialization. Using field sampling and phylogenetic analyses of butterfly fauna over an entire alpine region, we show that butterfly specialization (measured as the mean phylogenetic distance between utilized host plants) decreases at higher elevations, alongside a decreasing gradient of plant diversity. Consistent with current hypotheses on the relationship between biodiversity and the strength of species interactions, we experimentally show that a higher level of generalization at high elevations is associated with lower levels of plant resistance: across 16 pairs of plant species, low-elevation plants were more resistant vis-à-vis their congeneric alpine relatives. Thus, the links between diversity, herbivore diet specialization, and plant resistance along an elevation gradient suggest a causal relationship analogous to that hypothesized along latitudinal gradients. PMID:22957184

Pellissier, Loïc; Fiedler, Konrad; Ndribe, Charlotte; Dubuis, Anne; Pradervand, Jean-Nicolas; Guisan, Antoine; Rasmann, Sergio

2012-08-01

290

Shifts in species richness, herbivore specialization, and plant resistance along elevation gradients  

PubMed Central

Environmental gradients have been postulated to generate patterns of diversity and diet specialization, in which more stable environments, such as tropical regions, should promote higher diversity and specialization. Using field sampling and phylogenetic analyses of butterfly fauna over an entire alpine region, we show that butterfly specialization (measured as the mean phylogenetic distance between utilized host plants) decreases at higher elevations, alongside a decreasing gradient of plant diversity. Consistent with current hypotheses on the relationship between biodiversity and the strength of species interactions, we experimentally show that a higher level of generalization at high elevations is associated with lower levels of plant resistance: across 16 pairs of plant species, low-elevation plants were more resistant vis-à-vis their congeneric alpine relatives. Thus, the links between diversity, herbivore diet specialization, and plant resistance along an elevation gradient suggest a causal relationship analogous to that hypothesized along latitudinal gradients.

Pellissier, Loic; Fiedler, Konrad; Ndribe, Charlotte; Dubuis, Anne; Pradervand, Jean-Nicolas; Guisan, Antoine; Rasmann, Sergio

2012-01-01

291

Effect of ploughing on plant species abundance and diversity in the northwestern coastal desert of Egypt  

Microsoft Academic Search

This study focuses on the effect of ploughing on plant abundance,vegetation cover, species richness, and taxonomic diversity during the growingseasons (winter and spring) of 1992 and 2000 in the habitat of inland plateau(natural habitat), 21 km south of Mersa-Matrouh (Egypt).Ninety-five species belonging to 27 families were recorded. High percentages oflife-forms and a large number of species were recorded in ploughed

Sania K. Hammouda; Selim Z. Heneidy

2003-01-01

292

What does it take to be a plant pathogen: genomic insights from Streptomyces species  

Microsoft Academic Search

Plant pathogenicity is rare in the genus Streptomyces, with only a dozen or so species possessing this trait out of the more than 900 species described. Nevertheless, such species\\u000a have had a significant impact on agricultural economies throughout the world due to their ability to cause important crop\\u000a diseases such as potato common scab, which is characterized by lesions that

Dawn R. D. Bignell; José C. Huguet-Tapia; Madhumita V. Joshi; Gregg S. Pettis; Rosemary Loria

2010-01-01

293

Species-Specific Seed Dispersal in an Obligate AntPlant Mutualism  

Microsoft Academic Search

Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what

Elsa Youngsteadt; Jeniffer Alvarez Baca; Jason Osborne; Coby Schal; Nigel E. Raine

2009-01-01

294

Predicting rarity and decline in animals, plants, and mushrooms based on species attributes and indicator groups.  

PubMed

In decisions on nature conservation measures, we depend largely on knowledge of the relationship between threats and environmental factors for a very limited number of species groups, with relevant environmental factors often being deduced from the relationship between threat and species traits. But can relationships between traits and levels of threats be identified across species from completely different taxonomic groups; and how accurately do well-known taxonomic groups indicate levels of threat in other species groups? To answer these questions, we first made a list of 152 species attributes of morphological and demographic traits and habitat requirements. Based on these attributes we then grew random forests of decision trees for 1183 species in the 18 different taxonomic groups for which we had Red Lists available in the Netherlands, using these to classify animals, plants, and mushrooms according to their rarity and decline. Finally, we grew random forests for four species groups often used as indicator groups to study how well the relationship between attribute and decline within these groups reflected that relationship within the larger taxonomic group to which these groups belong. Correct classification of rarity based on all attributes was as high as 88% in animals, 85% in plants, and 94% in mushrooms and correct classification of decline was 78% in animals, 69% in plants, and 70% in mushrooms. Vertebrates indicated decline in all animals well, as did birds for all vertebrates and vascular plants for all plants. However, butterflies poorly indicated decline in all insects. Random forests are a useful tool to relate rarity and decline to species attributes thereby making it possible to generalize rarity and decline to a wider set of species groups. Random forests can be used to estimate the level of threat to complete faunas and floras of countries or regions. In regions like the Netherlands, conservation policy based on attributes known to be relevant for the decline to birds, vertebrates or plants will probably also impact all aboveground terrestrial and freshwater macrofauna or macrophytes. PMID:24223278

Musters, C J M; Kalkman, Vincent; van Strien, Arco

2013-09-01

295

Predicting rarity and decline in animals, plants, and mushrooms based on species attributes and indicator groups  

PubMed Central

In decisions on nature conservation measures, we depend largely on knowledge of the relationship between threats and environmental factors for a very limited number of species groups, with relevant environmental factors often being deduced from the relationship between threat and species traits. But can relationships between traits and levels of threats be identified across species from completely different taxonomic groups; and how accurately do well-known taxonomic groups indicate levels of threat in other species groups? To answer these questions, we first made a list of 152 species attributes of morphological and demographic traits and habitat requirements. Based on these attributes we then grew random forests of decision trees for 1183 species in the 18 different taxonomic groups for which we had Red Lists available in the Netherlands, using these to classify animals, plants, and mushrooms according to their rarity and decline. Finally, we grew random forests for four species groups often used as indicator groups to study how well the relationship between attribute and decline within these groups reflected that relationship within the larger taxonomic group to which these groups belong. Correct classification of rarity based on all attributes was as high as 88% in animals, 85% in plants, and 94% in mushrooms and correct classification of decline was 78% in animals, 69% in plants, and 70% in mushrooms. Vertebrates indicated decline in all animals well, as did birds for all vertebrates and vascular plants for all plants. However, butterflies poorly indicated decline in all insects. Random forests are a useful tool to relate rarity and decline to species attributes thereby making it possible to generalize rarity and decline to a wider set of species groups. Random forests can be used to estimate the level of threat to complete faunas and floras of countries or regions. In regions like the Netherlands, conservation policy based on attributes known to be relevant for the decline to birds, vertebrates or plants will probably also impact all aboveground terrestrial and freshwater macrofauna or macrophytes.

Musters, C J M; Kalkman, Vincent; van Strien, Arco

2013-01-01

296

Identifying plant species using MIR and TIR (2 - 14 ?m) emissivity spectra  

NASA Astrophysics Data System (ADS)

Tittle: Identifying plant species using MIR and TIR (2 - 14 µm) emissivity spectra Identification plant species using remote sensing is generally limited by the similarity of their reflectance spectra in the visible, NIR and SWIR domains. Laboratory measured emissivity spectra in the mid to thermal infrared (MIR-TIR; 2 µm - 14 µm) shows significant differences. The laboratory emissivity spectra of thirteen common broad leaved species, comprising 3024 spectral bands in the MIR and TIR, were analyzed. For each wavelength the differences between the species were tested for significance using the one way analysis of variance (ANOVA) with the post-hoc Tukey HSD test. The emissivity spectra of the analysed species were found to be statistically different at various wavebands. Subsequently, six spectral bands were selected (based on the histogram of separable pairs of species for each waveband) to quantify the separability between each species pair based on the Jefferies Matusita (JM) distance. Out of 78 combinations, 76 pairs had a significantly different JM distance. Using the selected six wavebands for multiple plant species, overall classification accuracy of 92 % was achieved. This means that careful selection of hyperspectral bands in the MIR and TIR (2.5 µm - 14 µm) results in reliable species discrimination. Keywords: Spectral emissivity, J-M distance, ANOVA, Tukey HSD, spectral separability, Kirchhoff law

Ullah, S.; Schlerf, M.; Skidmore, A. K.; Hecker, C.

2012-04-01

297

Global warming reduces plant reproductive output for temperate multi-inflorescence species on the Tibetan plateau.  

PubMed

• Temperature is projected to increase more during the winter than during the summer in cold regions. The effects of winter warming on reproductive effort have not been examined for temperate plant species. • Here, we report the results of experimentally induced seasonal winter warming (0.4 and 2.4°C increases in growing and nongrowing seasons, respectively, using warmed and ambient open-top chambers in a Tibetan Plateau alpine meadow) for nine indeterminate-growing species producing multiple (single-flowered or multi-flowered) inflorescences and three determinate-growing species producing single inflorescences after a 3-yr period of warming. • Warming reduced significantly flower number and seed production per plant for all nine multi-inflorescence species, but not for the three single-inflorescence species. Warming had an insignificant effect on the fruit to flower number ratio, seed size and seed number per fruit among species. The reduction in seed production was largely attributable to the decline in flower number per plant. The flowering onset time was unaffected for nine of the 12 species. Therefore, the decline in flower production and seed production in response to winter warming probably reflects a physiological response (e.g. metabolic changes associated with flower production). • Collectively, the data indicate that global warming may reduce flower and seed production for temperate herbaceous species and will probably have a differential effect on single- vs multi-inflorescence species. PMID:22591333

Liu, Yinzhan; Mu, Junpeng; Niklas, Karl J; Li, Guoyong; Sun, Shucun

2012-07-01

298

Advances in the reintroduction of rare and endangered wild plant species.  

PubMed

Human disturbance and climate change have increased the risk of extinction for rare and endangered wild plant species. One effective way to conserve these rare and endangered species is through reintroduction. In this review, we summarize the advances in wild plant reintroduction from five perspectives: the establishment of reintroduction biology as an important tool for biodiversity conservation; the importance of genetic diversity in reintroduction; reintroduction under global climate change; recruitment limitation in reintroduction; and reintroduction and ecological restoration. In addition, we consider the future of plant reintroduction strategies. PMID:24824586

Ren, Hai; Jian, ShuGuang; Liu, HongXiao; Zhang, QianMei; Lu, HongFang

2014-06-01

299

Influence of Selected Plant Species on Hatching of Eggs and Development of Juveniles of Heterodera glycines.  

PubMed

The influence of selected plant species on egg hatch and subsequent development of Heterodera glycines race 3 was investigated. Plants tested included four soybean cultivars, red clover, alfalfa, hairy vetch, field corn, sweet corn, cabbage, tobacco, cotton, and wheat. Soybean stimulated egg hatching more than any of the other plant species, with H. glycines-resistant cultivars being more stimulating than susceptible ones. Hairy vetch also increased hatch. Roots of cabbage, red clover, alfalfa, and hairy vetch were readily penetrated by juveniles of H. glycines. Maturation to adult occurred only on soybean and hairy vetch. PMID:19283087

Schmitt, D P; Riggs, R D

1991-01-01

300

Habitat area and climate stability determine geographical variation in plant species range sizes  

PubMed Central

Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ? 85 000 plant species across the New World. We assess prominent hypothesised range-size controls, finding that plant range sizes are codetermined by habitat area and long- and short-term climate stability. Strong short- and long-term climate instability in large parts of North America, including past glaciations, are associated with broad-ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small-ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen concerns over the potential effects of future climate change and habitat loss on biodiversity.

Morueta-Holme, Naia; Enquist, Brian J; McGill, Brian J; Boyle, Brad; J?rgensen, Peter M; Ott, Jeffrey E; Peet, Robert K; Simova, Irena; Sloat, Lindsey L; Thiers, Barbara; Violle, Cyrille; Wiser, Susan K; Dolins, Steven; Donoghue, John C; Kraft, Nathan J B; Regetz, Jim; Schildhauer, Mark; Spencer, Nick; Svenning, Jens-Christian

2013-01-01

301

Tropical Plant-Herbivore Networks: Reconstructing Species Interactions Using DNA Barcodes  

PubMed Central

Plants and their associated insect herbivores, represent more than 50% of all known species on earth. The first step in understanding the mechanisms generating and maintaining this important component of biodiversity is to identify plant-herbivore associations. In this study we determined insect-host plant associations for an entire guild of insect herbivores using plant DNA extracted from insect gut contents. Over two years, in a tropical rain forest in Costa Rica (La Selva Biological Station), we recorded the full diet breadth of rolled-leaf beetles, a group of herbivores that feed on plants in the order Zingiberales. Field observations were used to determine the accuracy of diet identifications using a three-locus DNA barcode (rbcL, trnH-psbA and ITS2). Using extraction techniques for ancient DNA, we obtained high-quality sequences for two of these loci from gut contents (rbcL and ITS2). Sequences were then compared to a comprehensive DNA barcode library of the Zingiberales. The rbcL locus identified host plants to family (success/sequence?=?58.8%) and genus (success/sequence?=?47%). For all Zingiberales except Heliconiaceae, ITS2 successfully identified host plants to genus (success/sequence?=?67.1%) and species (success/sequence?=?61.6%). Kindt’s sampling estimates suggest that by collecting ca. four individuals representing each plant-herbivore interaction, 99% of all host associations included in this study can be identified to genus. For plants that amplified ITS2, 99% of the hosts can be identified to species after collecting at least four individuals representing each interaction. Our study demonstrates that host plant identifications at the species-level using DNA barcodes are feasible, cost-effective, and reliable, and that reconstructing plant-herbivore networks with these methods will become the standard for a detailed understanding of these interactions.

Garcia-Robledo, Carlos; Erickson, David L.; Staines, Charles L.; Erwin, Terry L.; Kress, W. John

2013-01-01

302

Transfer of elements relevant to radioactive waste from soil to five boreal plant species.  

PubMed

In long-term safety assessment models for radioactive waste disposal, uptake of radionuclides by plants is an important process with possible adverse effects in ecosystems. Cobalt-60, (59,63)Ni, (93)Mo, and (210)Pb are examples of long-living radionuclides present in nuclear waste. The soil-to-plant transfer of stable cobalt, nickel, molybdenum and lead and their distribution across plant parts were investigated in blueberry (Vaccinium myrtillus), May lily (Maianthemum bifolium), narrow buckler fern (Dryopteris carthusiana), rowan (Sorbus aucuparia) and Norway spruce (Picea abies) at two boreal forest sites in Eastern Finland. The concentrations of all of the studied elements were higher in roots than in above-ground plant parts showing that different concentration ratios (CR values) are needed for modelling the transfer to roots and stems/leaves. Some significant differences in CR values were found in comparisons of different plant species and of the same species grown at different sites. However, large within-species variation suggests that it is not justified to use different CR values for modelling soil-to-plant transfer of these elements in the different boreal forest plant species. PMID:21190719

Roivainen, Päivi; Makkonen, Sari; Holopainen, Toini; Juutilainen, Jukka

2011-04-01

303

Infrared Spectroscopy of Pollen Identifies Plant Species and Genus as Well as Environmental Conditions  

PubMed Central

Background It is imperative to have reliable and timely methodologies for analysis and monitoring of seed plants in order to determine climate-related plant processes. Moreover, impact of environment on plant fitness is predominantly based on studies of female functions, while the contribution of male gametophytes is mostly ignored due to missing data on pollen quality. We explored the use of infrared spectroscopy of pollen for an inexpensive and rapid characterization of plants. Methodology The study was based on measurement of pollen samples by two Fourier transform infrared techniques: single reflectance attenuated total reflectance and transmission measurement of sample pellets. The experimental set, with a total of 813 samples, included five pollination seasons and 300 different plant species belonging to all principal spermatophyte clades (conifers, monocotyledons, eudicots, and magnoliids). Results The spectroscopic-based methodology enables detection of phylogenetic variations, including the separation of confamiliar and congeneric species. Furthermore, the methodology enables measurement of phenotypic plasticity by the detection of inter-annual variations within the populations. The spectral differences related to environment and taxonomy are interpreted biochemically, specifically variations of pollen lipids, proteins, carbohydrates, and sporopollenins. The study shows large variations of absolute content of nutrients for congenital species pollinating in the same environmental conditions. Moreover, clear correlation between carbohydrate-to-protein ratio and pollination strategy has been detected. Infrared spectral database with respect to biochemical variation among the range of species, climate and biogeography will significantly improve comprehension of plant-environment interactions, including impact of global climate change on plant communities.

Zimmermann, Boris; Kohler, Achim

2014-01-01

304

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau  

PubMed Central

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages.

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-01-01

305

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species  

SciTech Connect

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled conditions and supplied with 1 mg L{sup {minus}1} of each trace element individually for 10 d. Except B, all elements accumulated to much higher concentrations in roots than in shoots. Highest shoot tissue concentrations (mg kg{sup {minus}1} DW) of the various trace elements were attained by the following species: umbrella plant (Cyperus alternifolius L.) for Mn (198) and Cr (44); water zinnia (Wedelia trilobata Hitchc.) for Cd (148) and Ni (80); smartweed (Polygonum hydropiperoides Michx.) for Cu (95) and Pb (64); water lettuce (Pistia stratiotes L.) for Hg (92), As (34), and Se (39); and mare's tail (hippuris vulgaris L.) for B (1132). Whereas, the following species attained the highest root tissue concentrations (mg kg{sup {minus}1} DW); stripped rush (Baumia rubiginosa) for Mn (1683); parrot's feather (Myriophyllum brasiliense Camb.) for Cd (1426) and Ni (1077); water lettuce for Cu (1038), Hg (1217), and As (177); smartweed for Cr (2980) and Pb (1882); mare's tail for B (1277); and monkey flower (Mimulus guttatus Fisch.) for Se (384). From a phytoremediation perspective, smartweed was probably the best plant species for trace element removal from wastewater due to its faster growth and higher plant density.

Qian, J.H.; Zayed, A.; Zhu, Y.L.; Yu, M.; Terry, N.

1999-10-01

306

Effect of fertiliser application and abandonment on plant species composition of Festuca rubra grassland  

NASA Astrophysics Data System (ADS)

Little is known about the effects of nitrogen (N), phosphorus (P) and potassium (K) application on soil chemical properties and plant species composition of mountain Festuca rubra grasslands. In this study, we aimed to determine whether fertiliser application affects plant species composition and soil properties during periods of management, and whether residual after-effects of fertiliser application can be detected eight years after its use is abandoned. The experiment with unfertilised control, PK treatment and treatments with low and higher level of NPK application under three (intensive management from 1993 to 1997) and two cut management (moderate management from 1997 to 1999) was established in the Jizera Mts. (Czech Republic) on F. rubra meadow and then the experiment was eight years abandoned. Immediately after the introduction of intensive management, a decrease in species richness and diversification of plant species composition occurred. Plant communities which had diversified in different fertiliser treatments persisted under moderately intensive management. The cover of Alopecurus pratensis increased to >50% while the cover of Agrostis capillaris decreased to <5% in NPK treatments during the period of intensive management. Trifolium repens became the dominant species in the PK treatment. Within eight years, under no management, the differences in plant species composition disappeared, species richness decreased and F. rubra, followed by Hypericum maculatum, became dominant in all treatments. The differences in biomass P concentration and plant available P and K concentrations in the soil were still detectable eight years after the last fertiliser application. As shown in this study, moderate application of NPK and consequent abandonment need not generate irreversible changes in species composition of mountain grassland.

Pavl?, Vilém; Gaisler, Jan; Pavl?, Lenka; Hejcman, Michal; Ludvíková, Vendula

2012-11-01

307

Temporal-spatial dynamics in orthoptera in relation to nutrient availability and plant species richness.  

PubMed

Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets), a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability) could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs) or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen deposition on higher trophic levels it is essential to take into account species life-history traits. PMID:23951232

Hendriks, Rob J J; Carvalheiro, Luisa G; Kleukers, Roy M J C; Biesmeijer, Jacobus C

2013-01-01

308

Temporal-Spatial Dynamics in Orthoptera in Relation to Nutrient Availability and Plant Species Richness  

PubMed Central

Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets), a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability) could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs) or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen deposition on higher trophic levels it is essential to take into account species life-history traits.

Hendriks, Rob J. J.; Carvalheiro, Luisa G.; Kleukers, Roy M. J. C.; Biesmeijer, Jacobus C.

2013-01-01

309

Primate species richness is determined by plant productivity: Implications for conservation  

PubMed Central

The explanation of patterns in species richness ranks among the most important tasks of ecology. Current theories emphasize the interaction between historical and geographical factors affecting the size of the regional species pool and of locally acting processes such as competitive exclusion, disturbance, productivity, and seasonality. Local species richness, or alpha diversity, of plants and primary consumers has been claimed to peak in habitats of low and intermediate productivity, which, if true, has major implications for conservation. Here, by contrast, we show that local richness of Neotropical primates (platyrrhines) is influenced by both historical biogeography and productivity but not by tree species richness or seasonality. This pattern indicates that habitats with the highest plant productivity are also the richest for many important primary consumers. We show further that fragmentation of Amazonian rain forests in the Pleistocene, if it occurred, appears to have had a negligible influence on primate alpha species richness.

Kay, Richard F.; Madden, Richard H.; Van Schaik, Carel; Higdon, David

1997-01-01

310

Bacterial communities of two parthenogenetic aphid species cocolonizing two host plants across the Hawaiian Islands.  

PubMed

Aphids (Hemiptera: Aphididae) have been the focus of several studies with respect to their interactions with inherited symbionts, but bacterial communities of most aphid species are still poorly characterized. In this research, we used bar-coded pyrosequencing to characterize bacterial communities in aphids. Specifically, we examined the diversity of bacteria in two obligately parthenogenetic aphid species (the melon aphid, Aphis gossypii, and the cardamom aphid, Pentalonia caladii) cocolonizing two plant species (taro, Colocasia esculenta, and ginger, Alpinia purpurata) across four Hawaiian Islands (Hawaii, Kauai, Maui, and Oahu). Results from this study revealed that heritable symbionts dominated the bacterial communities for both aphid species. The bacterial communities differed significantly between the two species, and A. gossypii harbored a more diverse bacterial community than P. caladii. The bacterial communities also differed across aphid populations sampled from the different islands; however, communities did not differ between aphids collected from the two host plants. PMID:21965398

Jones, Ryan T; Bressan, Alberto; Greenwell, April M; Fierer, Noah

2011-12-01

311

Species-specific effects of elevated ozone on wetland plants and decomposition processes.  

PubMed

Seven species from two contrasting wetlands, an upland bog and a lowland rich fen in North Wales, UK, were exposed to elevated ozone (150 ppb for 5 days and 20 ppb for 2 days per week) or low ozone (20 ppb) for four weeks in solardomes. The rich fen species were: Molinia caerulea, Juncus subnodulosus, Potentilla erecta and Hydrocotyle vulgaris and the bog species were: Carex echinata, Potentilla erecta and Festuca rubra. Senescence significantly increased under elevated ozone in all seven species but only Molinia caerulea showed a reduction in biomass under elevated ozone. Decomposition rates of plants exposed to elevated ozone, as measured by carbon dioxide efflux from dried plant material inoculated with peat slurry, increased for Potentilla erecta with higher hydrolytic enzyme activities. In contrast, a decrease in enzyme activities and a non-significant decrease in carbon dioxide efflux occurred in the grasses, sedge and rush species. PMID:20185216

Williamson, Jennifer; Mills, Gina; Freeman, Chris

2010-05-01

312

Bacterial Communities of Two Parthenogenetic Aphid Species Cocolonizing Two Host Plants across the Hawaiian Islands ?  

PubMed Central

Aphids (Hemiptera: Aphididae) have been the focus of several studies with respect to their interactions with inherited symbionts, but bacterial communities of most aphid species are still poorly characterized. In this research, we used bar-coded pyrosequencing to characterize bacterial communities in aphids. Specifically, we examined the diversity of bacteria in two obligately parthenogenetic aphid species (the melon aphid, Aphis gossypii, and the cardamom aphid, Pentalonia caladii) cocolonizing two plant species (taro, Colocasia esculenta, and ginger, Alpinia purpurata) across four Hawaiian Islands (Hawaii, Kauai, Maui, and Oahu). Results from this study revealed that heritable symbionts dominated the bacterial communities for both aphid species. The bacterial communities differed significantly between the two species, and A. gossypii harbored a more diverse bacterial community than P. caladii. The bacterial communities also differed across aphid populations sampled from the different islands; however, communities did not differ between aphids collected from the two host plants.

Jones, Ryan T.; Bressan, Alberto; Greenwell, April M.; Fierer, Noah

2011-01-01

313

Actual and potential use of population viability analyses in recovery of plant species listed under the US endangered species act.  

PubMed

Use of population viability analyses (PVAs) in endangered species recovery planning has been met with both support and criticism. Previous reviews promote use of PVA for setting scientifically based, measurable, and objective recovery criteria and recommend improvements to increase the framework's utility. However, others have questioned the value of PVA models for setting recovery criteria and assert that PVAs are more appropriate for understanding relative trade-offs between alternative management actions. We reviewed 258 final recovery plans for 642 plants listed under the U.S. Endangered Species Act to determine the number of plans that used or recommended PVA in recovery planning. We also reviewed 223 publications that describe plant PVAs to assess how these models were designed and whether those designs reflected previous recommendations for improvement of PVAs. Twenty-four percent of listed species had recovery plans that used or recommended PVA. In publications, the typical model was a matrix population model parameterized with ?5 years of demographic data that did not consider stochasticity, genetics, density dependence, seed banks, vegetative reproduction, dormancy, threats, or management strategies. Population growth rates for different populations of the same species or for the same population at different points in time were often statistically different or varied by >10%. Therefore, PVAs parameterized with underlying vital rates that vary to this degree may not accurately predict recovery objectives across a species' entire distribution or over longer time scales. We assert that PVA, although an important tool as part of an adaptive-management program, can help to determine quantitative recovery criteria only if more long-term data sets that capture spatiotemporal variability in vital rates become available. Lacking this, there is a strong need for viable and comprehensive methods for determining quantitative, science-based recovery criteria for endangered species with minimal data availability. Uso Actual y Potencial del Análisis de Viabilidad Poblacional para la Recuperación de Especies de Plantas Enlistadas en el Acta de Especies En Peligro de E.U.A. PMID:24033732

Zeigler, Sara L; Che-Castaldo, Judy P; Neel, Maile C

2013-12-01

314

Factors associated with plant species richness in a coastal tall-grass prairie  

USGS Publications Warehouse

In this study we examine the factors associated with variations in species richness within a remnant tall-grass prairie in order to gain insight into the relative importance of controlling variables. The study area was a small, isolated prairie surrounded by wetlands and located within the coastal prairie region, which occurs along the northwestern Gulf of Mexico coastal plain. Samples were taken along three transects that spanned the prairie. Parameters measured included micro-elevation, soil characteristics, indications of recent disturbance, above-ground biomass (including litter), light penetration through the plant canopy, and species richness. Species richness was found to correlate with micro-elevation, certain soil parameters, and light penetration through the canopy, but not with above-ground biomass. Structural equation analysis was used to assess the direct and indirect effects of micro-elevation, soil properties, disturbance, and indicators of plant abundance on species richness. The results of this analysis showed that observed variations in species richness were primarily associated with variations in environmental effects (from soil and microtopography) and were largely unrelated to variations in measures of plant abundance (biomass and light penetration). These findings suggest that observed variations in species richness in this system primarily resulted from environmental effects on the species pool. These results fit with a growing body of information that suggests that environmental effects on species richness are of widespread importance.

Grace, J. B.; Allain, L.; Allen, C.

2000-01-01

315

Active oxygen species as mediators of plant immunity: three case studies.  

PubMed

A burst of active oxygen species (AOS) is known to be involved in local cell death as part of plant defence against pathogens. It is, however, under dispute to what extent AOS can induce pathogen resistance and immunity throughout the plant. Three experimental strategies that reveal a primary role for AOS and a surprisingly low chemical and spatial specificity are now described for tobacco and Arabidopsis thaliana plants. Ozone is a gaseous AOS that was applied to non-transgenic plants. Hydrogen peroxide or singlet oxygen are AOS that were induced by high-light treatment of transgenic plants that contained antisense constructs inhibiting catalase activity or chlorophyll biosynthetic enzymes. In all cases, activated oxygen species, cellular lesions, ethylene and salicylic acid, and components of major plant defence systems (systemic acquired resistance, hypersensitive response) were induced, as was resistance towards pathogens (tobacco mosaic virus, Pseudomonas syringae or Peronospora parasitica). It is concluded that active oxygen species can act as mediators of plant immunity so that new non-pesticidal plant protection strategies could be developed. PMID:11030422

Sandermann, H

2000-08-01

316

Arbuscular mycorrhizal fungi from New Caledonian ultramafic soils improve tolerance to nickel of endemic plant species.  

PubMed

In order to improve knowledge about the role of arbuscular mycorrhizal fungi (AMF) in the tolerance to heavy metals in ultramafic soils, the present study investigated the influence of two Glomus etunicatum isolates from New Caledonian ultramafic maquis (shrubland), on nickel tolerance of a model plant species Sorghum vulgare, and of two ultramafic endemic plant species, Alphitonia neocaledonica and Cloezia artensis. In a first step, plants were grown in a greenhouse, on sand with defined concentrations of Ni, to appreciate the effects of the two isolates on the alleviation of Ni toxicity in controlled conditions. In a second step, the influence of the AMF on A. neocaledonica and C. artensis plants grown in a New Caledonian ultramafic soil rich in extractable nickel was investigated. Ni reduced mycorrhizal colonization and sporulation of the fungal isolates, but the symbionts increased plant growth and adaptation of endemic plant species to ultramafic conditions. One of the two G. etunicatum isolates showed a stronger positive effect on plant biomass and phosphorus uptake, and a greater reduction in toxicity symptoms and Ni concentration in roots and shoots. The symbionts seemed to act as a barrier to the absorption of Ni by the plant and reduced root-to-shoot Ni translocation. Results indicate the potential of selected native AMF isolates from ultramafic areas for ecological restoration of such degraded ecosystems. PMID:23588949

Amir, Hamid; Lagrange, Alexandre; Hassaïne, Nadine; Cavaloc, Yvon

2013-10-01

317

Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species  

PubMed Central

The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae), we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination). The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

Reid, Anya; Hooper, Robyn; Molenda, Olivia; Lortie, Christopher J.

2014-01-01

318

The Combined Effects of Salts and Calcium on Growth and Mineral Accumulation of Tetragonia tetragonioides - A Salt Removing Species  

Microsoft Academic Search

High soil salinity levels have drastic effects on the growth and yield of horticultural crops. Salination may be controlled by environmentally safe and clean techniques as the use of salt removing species. Tetragonia tetragonioides, a wild halophytic species has been studied for this purpose. It was studied the effect of high salt concentrations on growth and mineral composition and the

M. A. NEVES; M. G. MIGUEL; C. MARQUES; T. PANAGOPOULOS; J. BELTRAO

319

Differential effects of plant diversity on functional trait variation of grass species  

PubMed Central

Background and Aims Functional trait differences and trait adjustment in response to influences of the biotic environment could reflect niche partitioning among species. In this study, we tested how variation in above-ground plant traits, chosen as indicators for light and nitrogen acquisition and use, differs among taxonomically closely related species (Poaceae) to assess their potential for niche segregation at increasing plant diversity. Methods Traits of 12 grass species were measured in experimental grasslands (Jena Experiment) of varying species richness (from 1 to 60) and presence of particular functional groups (grasses, legumes, tall herbs and small herbs). Key Results Grass species increased shoot and leaf length, investment into supporting tissue (stem mass fraction) and specific leaf area as well as reduced foliar ?13C values with increasing species richness, indicating higher efforts for light acquisition. These species-richness effects could in part be explained by a higher probability of legume presence in more diverse communities. Leaf nitrogen concentrations increased and biomas s : N ratios in shoots decreased when grasses grew with legumes, indicating an improved nitrogen nutrition. Foliar ?15N values of grasses decreased when growing with legumes suggesting the use of depleted legume-derived N, while decreasing ?15N values with increasing species richness indicated a shift in the uptake of different N sources. However, efforts to optimize light and nitrogen acquisition by plastic adjustment of traits in response to species richness and legume presence, varied significantly among grass species. It was possible to show further that trait adjustment of grass species increased niche segregation in more diverse plant communities but that complementarity through niche separation may differ between light and nutrient acquisition. Conclusions The results suggest that even among closely related species such as grasses different strategies are used to cope with neighbours. This lack in redundancy in turn may facilitate complementary resource use and coexistence.

Gubsch, Marlen; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef; Lipowsky, Annett; Roscher, Christiane

2011-01-01

320

Screening Brazilian plant species for in vitro inhibition of 5-lipoxygenase.  

PubMed

Plants from the Brazilian flora were evaluated for the inhibition of 5-lipoxygenase. The species were selected based on their traditional use and on a chemosystematic approach. In total, 19 species belonging to 13 families have been investigated. Hedychium coronarium J. Koenig (Zingiberaceae), Xylopia frutescens Aubl. (Annonaceae) and Hymenaea courbaril L. (Leguminosae) presented a high 5-lipoxygenase inhibitory activity. Some hypothesis about the nature of the active compounds are discussed, based on reports of the chemical constitution of these species or other species from the same botanical family. PMID:10715848

Braga, F C; Wagner, H; Lombardi, J A; de Oliveira, A B

2000-01-01

321

Phytotoxicity of sulfamethazine soil pollutant to six legume plant species.  

PubMed

The effect of traces of sulfamethazine (SMZ) in soil (0.01, 0.1, 0.25, 1, 5, 15, and 20 mM) on cellular distribution of cytochrome c oxidase activity, shoot and root growth, and leachate electroconductivity was analyzed in germinating seeds of yellow lupin, pea, lentil, soybean, adzuki bean, and alfalfa. Results showed that a high activity of cytochrome c oxidase in mitochondria correlated with high seed vigor and viability. The appearance of necroses and root decay was associated with a decrease in the activity of mitochondrial cytochrome c oxidase but was accompanied by an increase in cytosolic cytochrome c oxidase activity. A short exposure period of seeds (3 and 6 d) to sulfamethazine did not influence germination. Elongation of roots and stems was more sensitive than germination rate as an indicator of soil contamination by sulfamethazine. Among all tested leguminous plants, yellow lupin was the most reliable bioindicator of SMZ contaminated soil. PMID:20706947

Piotrowicz-Cie?lak, Agnieszka I; Adomas, Barbara; Na?ecz-Jawecki, Grzegorz; Michalczyk, Dariusz J

2010-01-01

322

A comparison of crop and non-crop plants as sensitive indicator species for regulatory testing.  

PubMed

The effectiveness of regulatory non-target plant testing using crop species to predict the phytotoxicicity of herbicides to non-crop species was evaluated for eleven herbicides. These herbicides were representative of eight chemical classes and six modes of action. Data for non-crop plants from pre-emergence and post-emergence efficacy screening studies were compared with those for the most sensitive crop species defined by regulatory tests conducted to meet US EPA requirements. Testing under pre-emergence conditions for ten compounds indicated that for five of the compounds (K-815910, trifluralin, pyridyloxy A, pyridyloxy B and cyanazine), the most sensitive crop species was more sensitive than all the non-crop species evaluated. For metsulfuron-methyl, chlorimuron-ethyl, hexazinone and bromacil, only one of the non-crop species evaluated was more sensitive than the most sensitive crop species from regulatory tests. Data for the tenth compound, chloroacetamide, showed that four of 32 non-crop species tested in efficacy screens had at least one rate at which greater visual effects were observed than were observed for the most sensitive crop response in a regulatory test. The results of post-emergence exposure comparisons for five of the compounds (pyridyloxy A, cloransulam-methyl, chlorimuron-ethyl, cyanazine and hexazinone) indicated that the most sensitive crop species were more sensitive than all the non-crop species evaluated. Data for pyridyloxy B, metsulfuron-methyl and bromacil indicated that only one of the non-crop species evaluated was more sensitive than the most sensitive crop species. For trifluralin, three of the eight non-crop species were more sensitive than the most sensitive crop species. Data for K-815910 indicated that four of the fourteen non-crop species tested were marginally more sensitive than the most sensitive crop, but were within the same range of sensitivity. These results indicate that the current regulatory test batteries and methods using crop species effectively provide suitable sensitive indicator plants for the eleven diverse herbicides evaluated. This comparison indicates that crop species sensitivity to test substances is likely to be representative of non-crop herbaceous species response, regardless of chemical class, mode of action and magnitude or route of exposure. PMID:12476989

McKelvey, Robert A; Wright, John P; Honegger, Joy L

2002-12-01

323

Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan.  

PubMed

We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populus maximowiczii, Salix hultenii var. angustifolia and Salix sachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating low ECM fungal diversity. ECM colonization ranged from 17 to 42% of root tips. Using morphotyping and molecular analyses, 15 ECM fungi were identified. ECM fungi differed greatly between hosts. However, Laccaria amethystea, Hebeloma mesophaeum, Thelephora terrestris and other Thelephoraceae had high relative colonization, constituting the majority of the ECM colonization in the roots of each plant species. These ECM fungi may be important for the establishment of pioneer woody plant species and further revegetation at Mt. Usu volcano. PMID:17216274

Obase, Keisuke; Tamai, Yutaka; Yajima, Takashi; Miyamoto, Toshizumi

2007-05-01

324

Phytotoxicity of biosolids and screening of selected plant species with potential for mercury phytoextraction.  

PubMed

Mercury contaminated stockpiles of biosolids (3.5-8.4 mg kg(-1) Hg) from Melbourne Water's Western Treatment Plant (MW-WTP) were investigated to evaluate the possibility for their phytoremediation. Nine plant species (Atriplex codonocarpa, Atriplex semibaccata, Austrodanthonia caespitosa, Brassica juncea, Brassica napus, Gypsophila paniculata, Sorghum bicolor, Themeda triandra and Trifolium subterraneum) were screened for phytoextraction potential in Hg-contaminated biosolids from MW-WTP. In addition, the same plant species were germinated and grown in two other substrates (i.e. potting mix and potting mix spiked with mercury(II)). Growth measurements and the mercury uptake for all three substrates were compared. Some plant species grown in potting mix spiked with mercury(II) grew more vigorously than in the other two substrates and showed higher levels of sulphur in their tissues. These results suggested that the mercury stress activated defence mechanisms and it was hypothesised that this was the likely reason for the enhanced production of sulphur compounds in the plant species studied which stimulated their growth. Some species did not grow in biosolids because of the combined effect of high mercury toxicity and high salt content. Atriplex conodocarpa and Australodanthonia caespitose proved to be the most suitable candidates for mercury phytoextraction because of their ability to translocate mercury from roots to the above-ground tissues. PMID:19775810

Lomonte, Cristina; Doronila, Augustine I; Gregory, David; Baker, Alan J M; Kolev, Spas D

2010-01-15

325

Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae) Driven by Geographical Isolation and Host Plant Acquirement  

PubMed Central

The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP) and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families) and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI) and Cytochrome b (Cytb) genes, the nuclear elongation factor-1? (EF-1?) gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago)), Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya) was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum.

Zhang, Ruiling; Huang, Xiaolei; Jiang, Liyun; Lei, Fumin; Qiao, Gexia

2012-01-01

326

Evolutionary history determines how plant productivity responds to phylogenetic diversity and species richness  

PubMed Central

The relationship between biodiversity and ecosystem function has received a great deal of attention in ecological research and recent results, from re-analyses, suggest that ecosystem function improves with increases in phylogenetic diversity. However, many of these results have been generalized across a range of different species and clades, and plants with different evolutionary histories could display different relationships between biodiversity and ecosystem function. To experimentally test this hypothesis, we manipulated species richness and phylogenetic diversity using 26 species from two subgenera of the genus Eucalyptus (subgenus Eucalyptus and subgenus Symphyomyrtus). We found that plant biomass (a measurement of ecosystem function) sometimes, but not always, responded to increases in species richness and phylogenetic diversity. Specifically, Symphyomyrtus plants showed a positive response while no comparable effect was observed for Eucalyptus plants, showing that responses to biodiversity can vary across different phylogenetic groups. Our results show that the impacts of evolutionary history may complicate the relationship between the diversity of plant communities and plant biomass.

Schweitzer, Jennifer A.; Bailey, Joseph K.

2014-01-01

327

Presence of indicator plant species as a predictor of wetland vegetation integrity  

USGS Publications Warehouse

We fit regression and classification tree models to vegetation data collected from Ohio (USA) wetlands to determine (1) which species best predict Ohio vegetation index of biotic integrity (OVIBI) score and (2) which species best predict high-quality wetlands (OVIBI score >75). The simplest regression tree model predicted OVIBI score based on the occurrence of three plant species: skunk-cabbage (Symplocarpus foetidus), cinnamon fern (Osmunda cinnamomea), and swamp rose (Rosa palustris). The lowest OVIBI scores were best predicted by the absence of the selected plant species rather than by the presence of other species. The simplest classification tree model predicted high-quality wetlands based on the occurrence of two plant species: skunk-cabbage and marsh-fern (Thelypteris palustris). The overall misclassification rate from this tree was 13 %. Again, low-quality wetlands were better predicted than high-quality wetlands by the absence of selected species rather than the presence of other species using the classification tree model. Our results suggest that a species’ wetland status classification and coefficient of conservatism are of little use in predicting wetland quality. A simple, statistically derived species checklist such as the one created in this study could be used by field biologists to quickly and efficiently identify wetland sites likely to be regulated as high-quality, and requiring more intensive field assessments. Alternatively, it can be used for advanced determinations of low-quality wetlands. Agencies can save considerable money by screening wetlands for the presence/absence of such “indicator” species before issuing permits.

Stapanian, Martin A.; Adams, Jean V.; Gara, Brian

2013-01-01

328

Lipophilic profile of the edible halophyte Salicornia ramosissima.  

PubMed

Salicornia ramosissima J. Woods is considered, in the Iberian Peninsula and France, a gourmet product. Nevertheless, is one of the less studied Salicornia species. In this work, GC-MS was employed to, for the first time; fully characterise the lipophilic profile of S. ramosissima and to assess the effect of natural and extra irrigation in that profile. The obtained data showed esterified and free fatty acids, fatty alcohol, sterols, alkanes and aromatic acid derivatives, being palmitic acid, tetracosanol and octacosanol the most abundant compounds. The extra irrigation increases significantly (P<0.001) the content of esterified lipophilic compounds. Stigmastanol, 24-ethyl-?(22)-coprostenol, several secondary fatty alcohols and dicarboxylic acids were identified for the first time in Salicornia genus. Several of the detected compounds are known to have health benefits and our results suggest that S. ramosissima should be considered as an important dietary source of lipophilic phytochemicals. PMID:25038683

Isca, Vera M S; Seca, Ana M L; Pinto, Diana C G A; Silva, Helena; Silva, Artur M S

2014-12-15

329

Salt tolerant green crop species for sodium management in space agriculture  

NASA Astrophysics Data System (ADS)

Ecological system and materials recycling loop of space agriculture are quite tight compared to natural ecological system on Earth. Sodium management will be a keen issue for space agricul-ture. Human nutritional requirements include sodium salt. Since sodium at high concentration is toxic for most of plant growth, excreted sodium of human waste should be removed from compost fertilizer. Use of marine algae is promising for harvesting potassium and other min-erals required for plant growth and returning remained sodium to satisfy human need of its intake. Farming salt tolerant green crop species is another approach to manage sodium problem in both space and terrestrial agriculture. We chose ice plant and New Zealand spinach. These two plant species are widely accepted green vegetable with many recipe. Ice plant can grow at the salinity level of sea water, and contain sodium salt up to 30% of its dry mass. Sodium distributes mainly in its bladder cells. New Zealand spinach is a plant species found in the front zone of sea shore, and tolerant against high salinity as well. Plant body size of both species at harvest is quite large, and easy to farm. Capability of bio-remediation of high saline soil is examined with ice plant and New Zealand spinach. Incubation medium was chosen to contain high concentration of sodium and potassium at the Na/K ratio of human excreta. In case Na/K ratio of plant body grown by this medium is greatly higher than that of incubation medium or soil, these halophytes are effective to remediate soil for farming less tolerant plant crop. Experimental results was less positive in this context.

Yamashita, Masamichi; Hashimoto, Hirofumi; Tomita-Yokotani, Kaori; Shimoda, Toshifumi; Nose, Akihiro; Space Agriculture Task Force, J.

330

Woody plant species co-occurrence in Brazilian savannas under different fire frequencies  

NASA Astrophysics Data System (ADS)

Fire plays an important role in determining the structure of the vegetation of savannas. Consequently, frequent fires are expected to assemble closely related plant species with very similar fire-related functional traits. We assessed the influence of different fire frequencies on patterns of co-occurrence of woody species at a fine spatial scale in Brazilian savannas. We used quantile regressions to test the relationship between co-occurrence indices and both phylogenetic distances and functional differences, calculated for every possible pair of species. Our results indicated that fire changes the pattern of co-occurrence of woody plants. Functionally different species co-occurred predominantly in a site protected from fire, whereas functionally similar species co-occurred predominantly in sites frequently burned. However, we did not find correlations between co-occurrence and phylogenetic distance of species, due probably to the random distribution of some functional traits in the phylogeny of savanna species. Thus, fire acts as an important environmental filter at fine spatial scales in Brazilian savannas, promoting functional - but not phylogenetic - clustering of plants.

Silva, Igor Aurélio; Batalha, Marco Antônio

331

Toxicity Testing of Fifteen Non-Crop Plant Species with Six Herbicides in a Greenhouse Experiment: Implications for Risk Assessment  

Microsoft Academic Search

Estimation of risk to plants not targeted by herbicides when used in agricultural or forestry situations requires appropriate data on multiple species. Currently, many questions remain unresolved as to the adequate type and number of species to be tested. This paper presents the result of a unique greenhouse experiment where testing was performed with 15 non-crop plant species sprayed with

C. Boutin; N. Elmegaard; C. Kjær

2004-01-01

332

The Alpine Cushion Plant Silene acaulis as Foundation Species: A Bug’s-Eye View to Facilitation and Microclimate  

Microsoft Academic Search

Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms–predominantly other plant species. The hypothesis that cushion or nurse plants in

Olivia Molenda; Anya Reid; Christopher J. Lortie

2012-01-01

333

Shifts in stomatal traits following the domestication of plant species.  

PubMed

Stomata are the major gates regulating substrate availability for photosynthesis and water loss. Although both processes are critical to yield and to resource-use efficiency, we lack a comprehensive picture on how domestication and further breeding have impacted on leaf stomata. To fill this gap, stomatal sizes and densities were screened in cultivated and wild ancestor representatives of a uniquely large group of 24 herbaceous crops. Anatomical data and gas-exchange models were combined to compute maximum potential conductance to water, separately for upper and lower leaf sides. The evolution of maximum conductance under domestication was diverse. Several crops increased, others decreased (noticeably high-conductance species), and others kept a similar potential conductance following domestication. It was found that the contribution of upper leaf sides to maximum conductance was statistically higher in cultivated than in wild ancestors. For crops showing this response, reduced stomatal density in the lower side of domesticated leaves was responsible for the observed 'adaxialization' of conductance. Increases in the size of stomata at the upper epidermis played a comparatively minor role. Nevertheless, this overall response was varied in magnitude and direction, signalling crop-wise specificities. Observed patterns reflect only potential conductances based on anatomical traits and should be used with care until actual physiological outcomes are measured. Together with advancements in the developmental genetics of stomata, our findings might hint at new breeding avenues, focused on stomata distribution. Provided urgent needs for increasing yields, the opportunities of enhancing traits of the physiological relevance of stomata should not be ignored. PMID:23918960

Milla, Rubén; de Diego-Vico, Natalia; Martín-Robles, Nieves

2013-08-01

334

Global assessment of the effects of terrestrial acidification on plant species richness.  

PubMed

This study estimates the potential losses of vascular plant species richness due to terrestrial acidification for different world's biomes. We used empirical occurrence data of 2409 species from 140 studies and estimated the relative species richness - pH response curves using logistic regressions. The regressions were then used to quantify the fraction of species that are potentially lost due to soil pH changes. Although we found considerable variability within biomes, out results show that the pH at which species richness was maximized was found to be the lowest in (sub)tropical forests (pH = 4.1) and the highest in deserts (pH = 7.4). We also found that (sub)tropical moist forests are highly sensitive to decreases of in soil pH below 4.1. This study can be coupled with existing atmospheric deposition models to quantify the risk of species richness loss following soil acidification. PMID:23246621

Azevedo, Ligia B; van Zelm, Rosalie; Hendriks, A Jan; Bobbink, Roland; Huijbregts, Mark A J

2013-03-01

335

Physiological, anatomical and leaf hydraulic effects on leaf water ?18O enrichment in different plant species  

NASA Astrophysics Data System (ADS)

Stable oxygen isotope ratios (?18O) of plant and source waters are valuable tools in the analysis of water and carbon fluxes at leaf, plant, and ecosystem scales. Recent improvements in mechanistic models have significantly advanced the understanding of isotopic leaf water enrichment, which is an important source of ?18O variability in plants and ecosystems. However, the marked variability in leaf water ?18O values that have been reported for different plant species hampers efforts to interpret and then apply data on leaf water ?18O values for studies conducted at the ecosystem scale. To improve the understanding and application of ?18O values in leaf water, we tested the interplay of physiological, morphological, anatomical and leaf hydraulic properties as drivers of leaf water ?18O values across 17 Eucalyptus species growing in a common garden. We observed large differences in leaf water ?18O across the 17 species. These differences were only partly driven by physiological and leaf morphological differences across species. A sensitivity analysis using state-of-the-art leaf water enrichment models showed that the parameter - effective path length - (L) is of critical importance for the variability of leaf water ?18O across different species. The data show that L can be related to a suite of leaf properties that include physiology, anatomy and hydraulics. Consequently, consideration of leaf properties will significantly improve the interpretation of ?18O values in leaf water across different plant species and will therefore help in the application of ?18O values in carbon and water cycle assessments at both the plant and the ecosystem scale.

Kahmen, A.; Arndt, S. K.; Dawson, T. E.

2007-12-01

336

A feasibility study of perennial/annual plant species to restore soils contaminated with heavy metals  

NASA Astrophysics Data System (ADS)

A feasibility study was carried out to evaluate the application of perennial/annual plant species in a phytoextraction process of a previously washed industrial urban soil contaminated by nickel, arsenic and cupper. The plant species selected for this study were Ipomea (Ipomea variada); grass (Poa pratensis); grass mixture (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum sp.); Monks Cress (Tropaeolum majus); ficus (Ficus benajamina) and fern (Pteris cretica). Soil was characterized and it presented the following heavy metals concentrations (dry weight): 80 mg of Ni/kg, 456-656 mg of As/kg and 1684-3166 mg of Cu/kg. Germination and survival in contaminated soil tests were conducted, from these, P. pratensis was discarded and the rest of plant species tested were used for the phytoextraction selection test. After 4 months of growth, biomass production was determined, and content of Ni, As and Cu was analyzed in plant’s tissue. Metal biological absorption coefficient (BAC), bio-concentration factor (BCF) and translocation factor (TF), were calculated. Regarding to biomass generation it was observed, in every case, an inhibition of the plant growth compared with blanks sown in a non contaminated soil; inhibition ranged from 22.5% for the Monk cress to 98% for Ipomea. Even though the later presented high BAC, BCF and TF, its growth was severely inhibited, and therefore, due its low biomass generation, it is not recommended for phytoextraction under conditions for this study. Heavy metals concentrations in plant’s tissue (dry weight) were as high as 866 mg Cu/kg and 602 mg As/kg for grass mixture; and 825 mg As/kg was observed for Monks cress. Grass mixture and monks cress had high BAC, BCF and TF, also they had high metal concentrations in its plants tissues and the lowest growth inhibition rates; hence the application in phytoextraction processes of these plants is advisable.

Zacarías, Montserrat; Beltrán, Margarita; Gilberto Torres, Luis; González, Abelardo

337

Arsenic speciation in moso bamboo shoot--a terrestrial plant that contains organoarsenic species.  

PubMed

Arsenic is predominantly found as an inorganic species in most terrestrial plants. However, we found that a significant proportion of organic arsenic was present in moso bamboo (Phyllostachys pubescens Mazel) shoot in a market survey of arsenic species in edible terrestrial plants. Moso bamboo shoots from different producing areas in China were collected for analysis to confirm the ubiquity of methylated arsenic species. The total arsenic concentrations of bamboo shoots were determined by hydride generation coupled atomic fluorescence spectrometry (HG-AFS), ranging from 27.7 to 94.0 microg/kg. Information about arsenic species was acquired from cold trap-hydride generation-atomic absorption spectrometry (CT-HG-AAS). Dimethylarsinic acid (DMA) was present in the amount of 13.9% to 44.9% of sum of the arsenic species in all these samples. Monomethylarsonic acid (MMA) and trimethylarsine oxide (TMAO) were also detected in certain samples in the range of 4.2-16.5% and 11.8-18.4%, respectively. In addition, bamboo shoots collected in winter were found to have more total arsenic and organic arsenic than those collected in spring. To investigate the source of the organic arsenic in moso bamboo shoots, arsenic species in the rhizosphere soils of the plants were examined. The absence of organic arsenic in soils would suggest the possibility of formation of methylated arsenic in the plants. In addition, studies of arsenic speciation in the peel and core of winter bamboo shoots showed that all the cores contained organic arsenic while no organic arsenic was detected in the peels. The study provides useful information for better understanding of the distribution of arsenic species in terrestrial plants. PMID:16626784

Zhao, Rui; Zhao, Mengxia; Wang, Hui; Taneike, Yasuhito; Zhang, Xinrong

2006-12-01

338

Invasive species management restores a plant-pollinator mutualism in Hawaii  

USGS Publications Warehouse

1.The management and removal of invasive species may give rise to unanticipated changes in plant–pollinator mutualisms because they can alter the composition and functioning of plant–pollinator interactions in a variety of ways. To utilize a functional approach for invasive species management, we examined the restoration of plant–pollinator mutualisms following the large-scale removal of an invasive nectar thief and arthropod predator, Vespula pensylvanica. 2.We reduced V. pensylvanica populations in large plots managed over multiple years to examine the response of plant–pollinator mutualisms and the fruit production of a functionally important endemic Hawaiian tree species, Metrosideros polymorpha. To integrate knowledge of the invader's behaviour and the plant's mating system, we determined the efficacy of V. pensylvanica as a pollinator of M. polymorpha and quantified the dependence of M. polymorpha on animal pollination (e.g. level of self-compatibility and pollen limitation). 3.The reduction of V. pensylvanica in managed sites, when compared to unmanaged sites, resulted in a significant increase in the visitation rates of effective bee pollinators (e.g. introduced Apis mellifera and native Hylaeus spp.) and in the fruit production of M. polymorpha. 4.Apis mellifera, following the management of V. pensylvanica, appears to be acting as a substitute pollinator for M. polymorpha, replacing extinct or threatened bird and bee species in our study system. 5.Synthesis and applications. Fruit production of the native M. polymorpha was increased after management of the invasive pollinator predator V. pensylvanica; however, the main pollinators were no longer native but introduced. This research thus demonstrates the diverse impacts of introduced species on ecological function and the ambiguous role they play in restoration. We recommend incorporating ecological function and context into invasive species management as this approach may enable conservation managers to simultaneously minimize the negative and maximize the positive impacts (e.g. taxon substitution) of introduced species. Such novel restoration approaches are needed, especially in highly degraded ecosystems.

Hanna, Cause; Foote, David; Kremen, Claire

2013-01-01

339

Terrestrial Plant-Derived Anticancer Agents and Plant Species Used in Anticancer Research  

Microsoft Academic Search

Cancer is a major cause of death and the number of new cases, as well as the number of individuals living with cancer, is expanding continuously. Due to the enormous propensity of plants that synthesize mixtures of structurally diverse bioactive compounds, the plant kingdom is potentially a very diverse source of chemical constituents with tumor cytotoxic activity. Despite the successful

Spiridon E. Kintzios

2006-01-01

340

Cytotoxicity of Fusarium species mycotoxins and culture filtrates of Fusarium species isolated from the medicinal plant Tribulus terrestris to mammalian cells  

Microsoft Academic Search

Ayurvedic medicine, which uses decoctions made of medicinal plants, is used to cure diseases in many Asian countries including Sri Lanka. Although proper storage facilities for medicinal plants are unavailable in Sri Lanka, neither the potential for growth of toxigenic fungi nor their ability to produce mycotoxins in stored medicinal plants has been investigated. We isolated three Fusarium species, F.

Krishanthi Abeywickrama; G. A. Bean

1992-01-01

341

Evidence that arbuscular mycorrhizal and phosphate-solubilizing fungi alleviate NaCl stress in the halophyte Kosteletzkya virginica: nutrient uptake and ion distribution within root tissues.  

PubMed

The effects of an arbuscular mycorrhizal (AM) fungus, Glomus mosseae, and a phosphate-solubilizing microorganism (PSM), Mortierella sp., and their interactions, on nutrient (N, P and K) uptake and the ionic composition of different root tissues of the halophyte Kosteletzkya virginica (L.), cultured with or without NaCl, were evaluated. Plant biomass, AM colonization and PSM populations were also assessed. Salt stress adversely affected plant nutrient acquisition, especially root P and K, resulting in an important reduction in shoot dry biomass. Inoculation of the AM fungus or/and PSM strongly promoted AM colonization, PSM populations, plant dry biomass, root/shoot dry weight ratio and nutrient uptake by K. virginica, regardless of salinity level. Ion accumulation in root tissues was inhibited by salt stress. However, dual inoculation of the AM fungus and PSM significantly enhanced ion (e.g., Na(+), Cl(-), K(+), Ca(2+), Mg(2+)) accumulation in different root tissues, and maintained lower Na(+)/K(+) and Ca(2+)/Mg(2+) ratios and a higher Na(+)/Ca(2+) ratio, compared to non-inoculated plants under 100 mM NaCl conditions. Correlation coefficient analysis demonstrated that plant (shoot or root) dry biomass correlated positively with plant nutrient uptake and ion (e.g., Na(+), K(+), Mg(2+) and Cl(-)) concentrations of different root tissues, and correlated negatively with Na(+)/K(+) ratios in the epidermis and cortex. Simultaneously, root/shoot dry weight ratio correlated positively with Na(+)/Ca(2+) ratios in most root tissues. These findings suggest that combined AM fungus and PSM inoculation alleviates the deleterious effects of salt on plant growth by enabling greater nutrient (e.g., P, N and K) absorption, higher accumulation of Na(+), K(+), Mg(2+) and Cl(-) in different root tissues, and maintenance of lower root Na(+)/K(+) and higher Na(+)/Ca(2+) ratios when salinity is within acceptable limits. PMID:24343115

Zhang, Huan Shi; Qin, Feng Fei; Qin, Pei; Pan, Shao Ming

2014-07-01

342

BOREAS TGB-3 Plant Species Composition Data over the NSA Fen  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-3) team collected several data sets that contributed to understanding the measured trace gas fluxes over sites in the Northern Study Area (NSA). This data set contains information about the composition of plant species that were within the collars used to measure Net Ecosystem Exchange of CO2 (NEE). The species composition was identified to understand the differences in NEE among the various plant communities in the NSA fen. The data were collected in July of 1994 and 1996. The data are contained in comma-delimited, ASCII files.

Bubier, Jill L.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

343

Nutrient Foraging Traits in Ten Co-occurring Plant Species of Contrasting Life Forms  

SciTech Connect

Morphological responses of the root system were tested by assessing scale, precision, discrimination, and sensitivity. Observations of high variation between species in scale, precision and sensitivity. In herbaceous species alone, scale and precision were positively correlated. Sensitivity was not closely related to precision, indicating that proliferation of roots in fertile patches does not always yield growth benefits in heterogeneous soils. Plant life form was not correlated with precision or sensitivity; however, scale of response was greater in herbs than in woody plants-possibly due to different root growth rates.

Einsmann, J.C.; Jones, R.H.; Pu, M.; Mitchell, R.J.

1999-01-01

344

[Seed dispersal efficiency of forest herbaceous plant species by the ant Myrmica ruginodis].  

PubMed

We compared the ability of 33 plant species collected in forest to have their seeds dispersed by the wood red ant Myrmica ruginodis. The elaiosome-bearing seeds (species Chelidonium majus, Colchicum autumnale, Luzula forsteri, Viola reichenbachiana, Luzula multiflora, Melica uniflora) and the small and light caryopses of the grasses (Holcus mollis, Agrostis capillaris, Deschampsia flexuosa, Poa trivialis, Holcus lanatus) are the most efficiently collected by ants. The seed quantity removed by ants is correlated negatively with their length. No significant correlation is found between the rate of seed removal and the frequency of the plants in the field at the scale of the study. PMID:18355754

Delatte, Emilie; Chabrerie, Olivier

2008-04-01

345

Characterization of calcium oxalate biominerals in some (non-Cactaceae) succulent plant species.  

PubMed

The water-accumulating leaves of crassulacean acid metabolism plants belonging to five different families were investigated for the presence of biominerals by infrared spectroscopic and microscopic analyses. Spectroscopic results revealed that the mineral present in succulent species of Agavaceae, Aizoaceae, and Asphodelaceae was calcium oxalate monohydrate (whewellite, CaC2O4 x H2O). Crystals were predominantly found as raphides or solitary crystals of various morphologies. However, representative Crassulaceae members and a succulent species of Asteraceae did not show the presence of biominerals. Overall, these results suggest no correlation between calcium oxalate generation and crassulacean acid metabolism in succulent plants. PMID:20737908

Monje, Paula V; Baran, Enrique J

2010-01-01

346

Petrified Forest National Park Invasive Plant Species Survey and Mapping; 2002-2005  

USGS Publications Warehouse

We conducted a survey for invasive nonnative plant species at Petrified Forest National Park from 2002 through 2005. The survey employed a unique sampling design consisting of a grid of consecutive one-hectare cells as the sampling units. Our use of predetermined sampling units allowed all observations to be referenced to a fixed area with geographic coordinates that easily transferred to a geographic information system. Our field team surveyed 2,730 sampling units in three select areas for at least 1 year and 879 sampling units for 4 years. During this period we identified 40 different invasive plant species; more than half the invasive plants (22 species) were annual forbs and grasses. Four invasive plant species occurred in 25 percent or more of all sampling units observed in one or more years: Bromus tectorum, Erodium cicutarium, Salsola tragus, and Sisymbrium altissimum. Salsola tragus was the most abundant species in all years and occurred in more than 55 percent of all sampling units surveyed each year.

Thomas, Kathryn A.; Hunt, Randall; Arundel, Terry; Guertin, P.

2009-01-01

347

Functional diversity supports the physiological tolerance hypothesis for plant species richness along climatic gradients  

USGS Publications Warehouse

1. The physiological tolerance hypothesis proposes that plant species richness is highest in warm and/or wet climates because a wider range of functional strategies can persist under such conditions. Functional diversity metrics, combined with statistical modeling, offer new ways to test whether diversity-environment relationships are consistent with this hypothesis. 2. In a classic study by R. H. Whittaker (1960), herb species richness declined from mesic (cool, moist, northerly) slopes to xeric (hot, dry, southerly) slopes. Building on this dataset, we measured four plant functional traits (plant height, specific leaf area, leaf water content and foliar C:N) and used them to calculate three functional diversity metrics (functional richness, evenness, and dispersion). We then used a structural equation model to ask if ‘functional diversity’ (modeled as the joint responses of richness, evenness, and dispersion) could explain the observed relationship of topographic climate gradients to species richness. We then repeated our model examining the functional diversity of each of the four traits individually. 3. Consistent with the physiological tolerance hypothesis, we found that functional diversity was higher in more favorable climatic conditions (mesic slopes), and that multivariate functional diversity mediated the relationship of the topographic climate gradient to plant species richness. We found similar patterns for models focusing on individual trait functional diversity of leaf water content and foliar C:N. 4. Synthesis. Our results provide trait-based support for the physiological tolerance hypothesis, suggesting that benign climates support more species because they allow for a wider range of functional strategies.

Spasojevic, Marko J.; Grace, James B.; Harrison, Susan; Damschen, Ellen I.

2013-01-01

348

Phenome Analysis in Plant Species Using Loss-of-Function and Gain-of-Function Mutants  

PubMed Central

Analysis of genetic mutations is one of the most effective ways to investigate gene function. We now have methods that allow for mass production of mutant lines and cells in a variety of model species. Recently, large numbers of mutant lines have been generated by both ‘loss-of-function’ and ‘gain-of-function’ techniques. In parallel, phenotypic information covering various mutant resources has been acquired and released in web-based databases. As a result, significant progress in comprehensive pheno-type analysis is being made through the use of these tools. Arabidopsis and rice are two major model plant species in which genome sequencing projects have been completed. Arabidopsis is the most widely used experimental plant, with a large number of mutant resources and several examples of systematic phenotype analysis. Rice is a major crop species and is used as a model plant, with an increasing number of mutant resources. Other plant species are also being employed in functional genetics research. In this review, the present status of mutant resources for large-scale studies of gene function in plant research and the current perspective on using loss-of-function and gain-of-function mutants in phenome research will be discussed.

Kuromori, Takashi; Takahashi, Shinya; Kondou, Youichi; Shinozaki, Kazuo; Matsui, Minami

2009-01-01

349

A systematic approach to document cyclotide distribution in plant species from genomic, transcriptomic, and peptidomic analysis.  

PubMed

Cyclotides are a large family of plant peptides characterized by their cyclic cystine knot composed of a circular backbone and three disulfide bonds that impart exceptional stability. They, and several acyclic variants, have been isolated from plants within the Rubiaceae, Violaceae, Cucurbitaceae, Fabaceae, Solanaceae, and Poaceae families. A variety of chemical and genetic approaches have been applied for the discovery and characterization of cyclotides. As investigations of cyclotide expression, distribution, and phylogeny rapidly increase, the authors have proposed the inclusion of information pertaining to plant species that have been analyzed but do not appear to express cyclotides into the CyBase database. CyBase is dedicated to providing web tools and information about cyclic peptides and proteins to the scientific community. Including detailed information about sampling and analysis parameters of plant species that have been investigated but not published elsewhere should assist in the process of selecting species for establishing new cyclotide discovery projects, as well as for detailed reanalysis using alternative technical approaches. In summary, the collection and deposition of all plant species that have been examined (whether cyclotides have been found or not) would help to impart a deeper understanding of cyclotide discovery, evolution, and physiological function. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 100: 433-437, 2013. PMID:23907794

Gerlach, Samantha L; Göransson, Ulf; Kaas, Quentin; Craik, David J; Mondal, Debasis; Gruber, Christian W

2013-09-01

350

Agency interaction at the Savannah River Plant under the Endangered Species Act  

Microsoft Academic Search

The 300 square mile Savannah River Plant (SRP) offers a variety of protected habitats for endangered species including the alligator (resident), red-cockaded woodpecker (resident), short-nose sturgeon (migratory), and wood stock (fish-forager). The most recent of these four species to be listed by the US Fish and Wildlife Service (US FWS) is the wood stock. It had been observed prior to

H. E. Jr

1984-01-01

351

Antifungal and antibacterial activity of seven traditionally used South African plant species active against Candida albicans  

Microsoft Academic Search

Leaf extracts of seven South African plant species with minimal inhibitory concentrations of 0.1 mg\\/ml and below against Candida albicans based on a preliminary screening were evaluated for antibacterial and antifungal activities using microplate dilution method and bioautography. Aspergillus fumigatus, Micrococcus canis, C. albicans, Sporothrix schenckii and Cryptococcus neoformans were the fungal test organisms, while the bacterial species used were Staphylococcus

L. J. Shai; L. J. McGaw; P. Masoko; J. N. Eloff

2008-01-01

352

A Laboratory Study on Revegetation and Metal Uptake in Native Plant Species from Neutral Mine Tailings  

Microsoft Academic Search

Lygeum spartum, Zygophyllum fabago and Piptatherum miliaceum are typical plant species that grow in mine tailings in semiarid Mediterranean areas. The aim of this work was to investigate\\u000a metal uptake of these species growing on neutral mine tailings under controlled conditions and their response to fertilizer\\u000a additions. A neutral mine tailing (pH of soil solution of 7.1–7.2) with high total

Héctor M. Conesa; Rainer Schulin; Bernd Nowack

2007-01-01

353

Biodiversity and characterization of Staphylococcus species isolated from a small manufacturing dairy plant in Portugal  

Microsoft Academic Search

The level and the diversity of the staphylococcal community occurring in the environment and dairy products of a small manufacturing dairy plant were investigated. Species identification was performed using different molecular methods, viz. Multiplex-PCR, amplified ribosomal DNA restriction analysis (ARDRA), and sodA gene sequencing. The main species encountered corresponded to Staphylococcus equorum (41 isolates, 39.0%), S. saprophyticus (28 isolates, 26.7%)

José C. Soares; M. Rosário Marques; Freni K. Tavaria; Joana O. Pereira; F. Xavier Malcata; Manuela M. Pintado

2011-01-01

354

Stakeholders’ perceptions of the impacts of invasive exotic plant species in the Mediterranean region  

Microsoft Academic Search

Invasive species pose an increasing environmental problem across the globe, but to date socio-economic perspectives on this\\u000a problem have been limited. In this study stakeholder perceptions of the impacts of invasive exotic plant species on the islands\\u000a of Mallorca, Sardinia and Crete are examined through the use of semi-structured interviews, Likert scales and Contingent Valuation.\\u000a Results showed substantial concerns about

Douglas Bardsley; Gareth Edwards-Jones

2006-01-01

355

Species Composition of Bacterial Communities Influences Attraction of Mosquitoes to Experimental Plant Infusions  

Microsoft Academic Search

In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms\\u000a produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito\\u000a species, which are global vectors of dengue viruses. In laboratory experiments, gravid females

Loganathan Ponnusamy; Dawn M. Wesson; Consuelo Arellano; Coby Schal; Charles S. Apperson

2010-01-01

356

Heavy metal concentrations (Cd, Cu and Pb) in five aquatic plant species in Tasik Chini, Malaysia  

Microsoft Academic Search

The purpose of this study was to determine the levels of heavy metals namely cadmium (Cd), copper (Cu) and lead (Pb) in the\\u000a five aquatic plants. For this purpose, the concentration of heavy metals were measured in water and in the five aquatic plant\\u000a species, Lepironia articulata, Pandanus helicopus, Scirpus grossus, Cabomba furcata and Nelumbo nucifera, in 15 sites from

M. Ebrahimpour; I. Mushrifah

2008-01-01

357

Plant species effects on soil carbon and nitrogen dynamics in a temperate steppe of northern China  

Microsoft Academic Search

We evaluated plant species effects on soil carbon (C) and nitrogen (N) dynamics in a steppe ecosystem of northern China. In\\u000a two subsequent years, we measured soil properties in the top 10 cm of the soil under replicated mono-dominant plant patches\\u000a in two sites that differed in land-use history: a cultivated site (old field) and an uncultivated site (steppe). Both in

Lili Jiang; Xingguo Han; Ning Dong; Yanfen Wang; Paul Kardol

358

The influence of plant species on attraction and host acceptance in Cotesia glomerata (Hymenoptera: Braconidae)  

Microsoft Academic Search

Females of the larval parasitoidCotesia glomerata (L.) use plant-associated cues to locate their lepidopteran host,Pieris rapae L. In this study we investigated the influence of four host plant species,Brassica oleracea var.acephala (‘Vates’ kale),Tropaeolum majus (nasturtium),Lunaria annua (honesty), andCleome spinosa (spider flower), on two components of the host selection process inC. glomerata, namely, attraction and host acceptance. Choice tests in a

Betty Benrey; Robert F. Denno; Laure Kaiser

1997-01-01

359

Impacts of stressors on the emergence and growth of wetland plant species in Pennsylvania, USA  

Microsoft Academic Search

Agriculture and urbanization in the upland landscape often generate stressors, such as sedimentation and eutrophication, that\\u000a may negatively impact wetland plant communities. Individual plant species responses to stressors are also likely influenced\\u000a by the hydrologic and geomorphologic characteristics of different wetland hydrogeomorphic (HGM) subclasses. The goal of this\\u000a study was to determine to what extent the two stressors listed above

Wendy M. Mahaney; Denice H. Wardrop; Robert P. Brooks

2004-01-01

360

Nitric oxide counteracts cytotoxic processes mediated by reactive oxygen species in plant tissues  

Microsoft Academic Search

.   Many environmental conditions subject plants to oxidative stress, in which reactive oxygen species (ROS) are overproduced.\\u000a These ROS act as transduction signals in plant defense responses, but also cause effects that result in cellular damage. Since\\u000a nitric oxide (NO) is a bioactive molecule able to scavenge ROS, we analyzed its effect on some cytotoxic processes produced\\u000a by ROS in

María Verónica Beligni; Lorenzo Lamattina

1999-01-01

361

Species area relationships in mediterranean-climate plant communities  

USGS Publications Warehouse

SUMMARY: Polychlorinated biphenyls constitute a group of chlorine-bearing compounds of industrial origin that have permeated the natural environment throughout the world. Their chemical structure resembles that of some of the organochlorine pesticides. They are troublesome interferences in gas chromatographic analysis of these pesticides. Although methods have been developed to overcome analytical problems, measurements of quantity still are only approximate. Special studies in the United States, Netherlands, and Great Britain have traced PCB's to industrial effluent, but other possible sources have not been followed. Their use in paints, cartons, and insulating fluids suggests that environmental pollution may be from many different sources. PCB's are present in fish and wildlife in many countries of the world. Quantities are higher in animals living near industrial areas. PCB's build up in biological food chains with increases of tens to thousands of times from lower to higher organisms. Experimental studies have shown that PCB's have a toxicity to mallards, pheasants, bobwhite quail, coturnix quail, red-winged blackbirds, starlings, cowbirds, and grackles that is of the same order as the toxicity of DDE to these species. Overt signs of poisoning also are similar to those caused by compounds of the DDT group. Toxic effects of DDE and Aroclor 1254 to coturnix chicks were additive, but not synergistic. PCB's containing higher percentages of chlorine are more toxic to birds than those containing lower percentages. PCB's of foreign manufacture contained contaminants to an extent that greatly increased their toxicity Aroclor 1242. Statistical evaluations of the role that different chemicals may play in thinning of eggshells of brown pelicans show that DDE residues correlate better with shell thinning than do residues of dieldrin or PCB's. Studies of the effects of PCB's in the environment are as yet insufficient for well-rounded conclusions. The evidence available indicates that they must be viewed as potential problems until fuller data can be assembled. Toxicity to insects of PCB's of different degrees of chlorination is the reverse of the pattern in birds: the lower chlorinations are more toxic to insects. PCB's enhanced the toxicity of dieldrin and DDT to insects. Shrimp are very sensitive to PCB's and most will die as a result of 20-day exposure to a concentration of 5 ppb. PCB's also inhibit shell growth of oysters. Fish and crabs are less sensitive; all accumulate residues to many times the concentrations in the water, and a test with crabs showed that they lost the residues very slowly. Residues of PCB's in the brains of birds killed by these compounds measure in the hundreds of parts per million. PCB's may have contributed to mortality of some birds in the field. PCB's induce microsomal enzyme activity in birds and mammals and the lower chlorinated mixtures have estrogenic activity in rats. Exposure to PCB's increased the susceptibility of mallard ducklings to duck hepatitis virus. Offspring of pheasants whose parents received high dosages of PCB's made poor choices in visual cliff tests. Egg production and hatching after pipping also were affected. Long-term studies of the reproductive effects of Aroclor 1254 on mallards and bobwhite quail and of Aroclor 1254 plus DDE on quail showed no significant differences from controls. In studies of chickens, however, egg production, hatchability, and shell thickness were impaired by high doses of Aroclor 1254 and by low doses of Aroclor 1242. Statistical evaluations of the role that different chemicals may play in thinning of eggshells of brown pelicans show that DDE residues correlate better with shell thinning than do residues of dieldrin or PCB's. Studies of the effects of PCB's in the environment are as yet insufficient for well-rounded conclusions. The evidence available indicates that they must be

Keeley, J. E.; Fotheringham, C. J.

2003-01-01

362

Conventional and PCR Detection of Aphelenchoides fragariae in Diverse Ornamental Host Plant Species.  

PubMed

A PCR-based diagnostic assay was developed for early detection and identification of Aphelenchoides fragariae directly in host plant tissues using the species-specific primers AFragFl and AFragRl that amplify a 169-bp fragment in the internal transcribed spacer (ITS1) region of ribosomal DNA. These species-specific primers did not amplify DNA from Aphelenchoides besseyi or Aphelenchoides ritzemabosi. The PCR assay was sensitive, detecting a single nematode in a background of plant tissue extract. The assay accurately detected A. fragariae in more than 100 naturally infected, ornamental plant samples collected in North Carolina nurseries, garden centers and landscapes, including 50 plant species not previously reported as hosts of Aphelenchoides spp. The detection sensitivity of the PCR-based assay was higher for infected yet asymptomatic plants when compared to the traditional, water extraction method for Aphelenchoides spp. detection. The utility of using NaOH extraction for rapid preparation of total DNA from plant samples infected with A. fragariae was demonstrated. PMID:19259510

McCuiston, Jamie L; Hudson, Laura C; Subbotin, Sergei A; Davis, Eric L; Warfield, Colleen Y

2007-12-01

363

Conventional and PCR Detection of Aphelenchoides fragariae in Diverse Ornamental Host Plant Species  

PubMed Central

A PCR-based diagnostic assay was developed for early detection and identification of Aphelenchoides fragariae directly in host plant tissues using the species-specific primers AFragFl and AFragRl that amplify a 169-bp fragment in the internal transcribed spacer (ITS1) region of ribosomal DNA. These species-specific primers did not amplify DNA from Aphelenchoides besseyi or Aphelenchoides ritzemabosi. The PCR assay was sensitive, detecting a single nematode in a background of plant tissue extract. The assay accurately detected A. fragariae in more than 100 naturally infected, ornamental plant samples collected in North Carolina nurseries, garden centers and landscapes, including 50 plant species not previously reported as hosts of Aphelenchoides spp. The detection sensitivity of the PCR-based assay was higher for infected yet asymptomatic plants when compared to the traditional, water extraction method for Aphelenchoides spp. detection. The utility of using NaOH extraction for rapid preparation of total DNA from plant samples infected with A. fragariae was demonstrated.

McCuiston, Jamie L.; Hudson, Laura C.; Subbotin, Sergei A.; Davis, Eric L.; Warfield, Colleen Y.

2007-01-01

364

A large, mobile pathogenicity island confers plant pathogenicity on Streptomyces species.  

PubMed

Potato scab is a globally important disease caused by polyphyletic plant pathogenic Streptomyces species. Streptomyces acidiscabies, Streptomyces scabies and Streptomyces turgidiscabies possess a conserved biosynthetic pathway for the nitrated dipeptide phytotoxin thaxtomin. These pathogens also possess the nec1 gene which encodes a necrogenic protein that is an independent virulence factor. In this article we describe a large (325-660 kb) pathogenicity island (PAI) conserved among these three plant pathogenic Streptomyces species. A partial DNA sequence of this PAI revealed the thaxtomin biosynthetic pathway, nec1, a putative tomatinase gene, and many mobile genetic elements. In addition, the PAI from S. turgidiscabies contains a plant fasciation (fas) operon homologous to and colinear with the fas operon in the plant pathogen Rhodococcus fascians. The PAI was mobilized during mating from S. turgidiscabies to the non-pathogens Streptomyces coelicolor and Streptomyces diastatochromogenes on a 660 kb DNA element and integrated site-specifically into a putative integral membrane lipid kinase. Acquisition of the PAI conferred a pathogenic phenotype on S. diastatochromogenes but not on S. coelicolor. This PAI is the first to be described in a Gram-positive plant pathogenic bacterium and is responsible for the emergence of new plant pathogenic Streptomyces species in agricultural systems. PMID:15686551

Kers, Johan A; Cameron, Kimberly D; Joshi, Madhumita V; Bukhalid, Raghida A; Morello, Joanne E; Wach, Michael J; Gibson, Donna M; Loria, Rosemary

2005-02-01

365

Type characters of non-native plant species in Great Lakes national parks (USA)  

USGS Publications Warehouse

Non-native plant species are increasing in frequency and abundance in many natural areas in the United States. In Midwestern National Parks, as much as one third of the flora may be non-native. It was hypothesized that botanical characters of these species could be used to typify them and improve the methods of predicting invasions. Data on 19 characters of 341 non-native species from the four Great Lakes national lakeshores (Apostle Islands, Indiana Dunes, Pictured Rocks, and Sleeping Bear Dunes) and invasive non-native species for the State of Wisconsin were collected and studied. For many of the species, little data could be found, but for 139 of them, data were collected for at least 80% of the characters. The frequencies of classes of the characters were tabulated and ranked to typify the most common non-native species. This led to a description of a 'type species' just for these four National Parks. Three species of Cirsium, including Canada (C. arvense), marsh (C. palustre) and bull thistle (C. vulgare), matched the type species better than other species. C. vulgare occurs in more National Parks than the other thistles.

Bennett, J. P.

2001-01-01

366

The Caribbean slipper spurge Euphorbia tithymaloides: the first example of a ring species in plants  

PubMed Central

A ring species arises when a parental population expands around an area of unsuitable habitat in such a way that when the two fronts meet they behave as distinct species while still being connected through a series of intergrading populations. Ring species offer great possibilities for studying the forces causing species divergence (e.g. the nature of pre-zygotic or post-zygotic reproductive isolation) or helping to maintain species integrity (e.g. reinforcement). Yet, ring species are extremely rare, and have only been documented convincingly in animals. Here, we present phylogenetic analyses of two nuclear gene regions from the Caribbean slipper spurge (Euphorbia tithymaloides) species complex that provide evidence that this group forms a ring species. These data show that the species complex originated in the area where Mexico and Guatemala meet, and expanded around the Caribbean basin along two distinct fronts: one eastward through the Yucatan Peninsula and into the Greater Antilles (GA); one southeastward through northern South America and then northward to the Lesser Antilles and eastern GA. The two terminal forms co-occur in the Virgin Islands and appear to be morphologically and ecologically distinct. Thus, our results suggest that Euphorbia tithymaloides is the first compelling example of a ring species in plants.

Cacho, N. Ivalu; Baum, David A.

2012-01-01

367

The Caribbean slipper spurge Euphorbia tithymaloides: the first example of a ring species in plants.  

PubMed

A ring species arises when a parental population expands around an area of unsuitable habitat in such a way that when the two fronts meet they behave as distinct species while still being connected through a series of intergrading populations. Ring species offer great possibilities for studying the forces causing species divergence (e.g. the nature of pre-zygotic or post-zygotic reproductive isolation) or helping to maintain species integrity (e.g. reinforcement). Yet, ring species are extremely rare, and have only been documented convincingly in animals. Here, we present phylogenetic analyses of two nuclear gene regions from the Caribbean slipper spurge (Euphorbia tithymaloides) species complex that provide evidence that this group forms a ring species. These data show that the species complex originated in the area where Mexico and Guatemala meet, and expanded around the Caribbean basin along two distinct fronts: one eastward through the Yucatan Peninsula and into the Greater Antilles (GA); one southeastward through northern South America and then northward to the Lesser Antilles and eastern GA. The two terminal forms co-occur in the Virgin Islands and appear to be morphologically and ecologically distinct. Thus, our results suggest that Euphorbia tithymaloides is the first compelling example of a ring species in plants. PMID:22696529

Cacho, N Ivalú; Baum, David A

2012-09-01

368

Plant-Species Diversity Correlates with Genetic Variation of an Oligophagous Seed Predator  

PubMed Central

Several characteristics of habitats of herbivores and their food-plant communities, such as plant-species composition and plant quality, influence population genetics of both herbivores and their host plants. We investigated how different ecological and geographic factors affect genetic variation in and differentiation of 23 populations of the oligophagous seed predator Lygaeus equestris (Heteroptera) in southwestern Finland and in eastern Sweden. We tested whether genetic differentiation of the L. equestris populations was related to the similarity of vegetation, and whether there was more within-population genetic variation in habitats with a high number of plant species or in those with a large population of the primary food plant, Vincetoxicum hirundinaria. We also tested whether genetic differentiation of the populations was related to the geographic distance, and whether location of the populations on islands or on mainland, island size, or population size affected within-population genetic variation. Pairwise FST ranged from 0 to 0.1 indicating low to moderate genetic differentiation of populations. Differentiation increased with geographic distance between the populations, but was not related to the similarity of vegetation between the habitats. Genetic variation within the L. equestris populations did not increase with the population size of the primary food plant. However, the more diverse the plant community the higher was the level of genetic variation within the L. equestris population. Furthermore, the level of genetic variation did not vary significantly between island and mainland populations. The effect of the population size on within-population genetic variation was related to island size. Usually small populations are susceptible to loss of genetic variation, but small L. equestris populations on large islands seemed to maintain a relatively high level of within-population genetic variation. Our findings suggest that, in addition to geographic and species-specific ecological factors, the plant community affects population genetic structure of oligophagous herbivores.

Laukkanen, Liisa; Mutikainen, Pia; Muola, Anne; Leimu, Roosa

2014-01-01

369

Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds  

SciTech Connect

The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds.. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl{sub 2}, and Hg(NO{sub 3}){sub 2}, were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots (<65 mg/kg), even though root mercury accumulation is significant (maximum 2298 mg/kg). Consequently, this plant species may not be suitable for mercury phyto-remediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phyto-extraction. During one experiment, Chinese brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 parts-per-million (ppm) and 1000 ppm HgCl{sub 2} powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl{sub 2}, or Hg(NO{sub 3}){sub 2}. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties. (authors)

Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L. [Institute for Clean Energy Technology (ICET), Mississippi State University, 205 Research Blvd, Starkville, MS 39759 (United States)

2007-07-01

370

76 FR 46361 - Endangered and Threatened Wildlife and Plants; Listing 23 Species on Oahu as Endangered and...  

Federal Register 2010, 2011, 2012, 2013

...plant species through the use of cooperative agreements and partnerships. The 2001 INRMP...species to be monitored over the 5-year implementation timeframe (U...as needed'' over the plan's 5-year implementation timeframe...

2011-08-02

371

Arbuscular mycorrhizal colonization of the dominant plant species in primary successional volcanic deserts on the Southeast slope of Mount Fuji  

Microsoft Academic Search

Arbuscular mycorrhizal (AM) colonization was observed on four plant species in primary successional volcanic deserts on the Southeast slope of Mount Fuji. The AM colonization of the dominant species, Polygonum cuspidatum, contradicts the conclusion that Polygonaceae are often regarded as being non-mycorrhizal species. The secondary dominant species, Polygonum weyrichii var. alpinum, formed no mycorrhizas. The roots of Cirsium purpuratum, Clematis

Bingyun Wu; Katsunori Isobe; Ryuichi Ishii

2004-01-01

372

75 FR 18232 - Endangered and Threatened Wildlife and Plants; 5-Year Status Reviews of 15 Caribbean Species  

Federal Register 2010, 2011, 2012, 2013

...and Plants; 5-Year Status Reviews of 15 Caribbean Species AGENCY: Fish and Wildlife...are initiating 5-year status reviews of 15 species under the Endangered Species Act...This notice announces our active review of 15 species currently listed as...

2010-04-09

373

Evaluation of Genome Sequencing Quality in Selected Plant Species Using Expressed Sequence Tags  

PubMed Central

Background With the completion of genome sequencing projects for more than 30 plant species, large volumes of genome sequences have been produced and stored in online databases. Advancements in sequencing technologies have reduced the cost and time of whole genome sequencing enabling more and more plants to be subjected to genome sequencing. Despite this, genome sequence qualities of multiple plants have not been evaluated. Methodology/Principal Finding Integrity and accuracy were calculated to evaluate the genome sequence quality of 32 plants. The integrity of a genome sequence is presented by the ratio of chromosome size and genome size (or between scaffold size and genome size), which ranged from 55.31% to nearly 100%. The accuracy of genome sequence was presented by the ratio between matched EST and selected ESTs where 52.93% ? 98.28% and 89.02% ? 98.85% of the randomly selected clean ESTs could be mapped to chromosome and scaffold sequences, respectively. According to the integrity, accuracy and other analysis of each plant species, thirteen plant species were divided into four levels. Arabidopsis thaliana, Oryza sativa and Zea mays had the highest quality, followed by Brachypodium distachyon, Populus trichocarpa, Vitis vinifera and Glycine max, Sorghum bicolor, Solanum lycopersicum and Fragaria vesca, and Lotus japonicus, Medicago truncatula and Malus × domestica in that order. Assembling the scaffold sequences into chromosome sequences should be the primary task for the remaining nineteen species. Low GC content and repeat DNA influences genome sequence assembly. Conclusion The quality of plant genome sequences was found to be lower than envisaged and thus the rapid development of genome sequencing projects as well as research on bioinformatics tools and the algorithms of genome sequence assembly should provide increased processing and correction of genome sequences that have already been published.

Shangguan, Lingfei; Han, Jian; Kayesh, Emrul; Sun, Xin; Zhang, Changqing; Pervaiz, Tariq; Wen, Xicheng; Fang, Jinggui

2013-01-01

374

Drought responses of Arrhenatherum elatius grown in plant assemblages of varying species richness  

NASA Astrophysics Data System (ADS)

Evidence exists that plant community diversity influences productivity of individual members and their resistance and resilience during and after perturbations. We simulated drought within the long-term EVENT experimental site in the Ecological-Botanical Garden, University of Bayreuth to understand how Arrhenatherum elatius (L.) responds to water stress when grown in three different plant assemblages. The set up consisted of five replications for each factorial combination of drought and plant assemblages differing in functional diversity. Leaf water potential (?L), leaf gas exchange, natural ?13C, plant biomass and cover were measured. Imposed drought had different effects on A. elatius, depending on plant assemblage composition. Severe water stress was however, avoided by slowing down the rate of decline in ?L, and this response was modified by community composition. High ?L was associated with high stomatal conductance and leaf photosynthesis. Biomass production of A. elatius increased due to drought stress only in the least diverse assemblage, likely due to increased tillering and competitive advantage against neighbors in the drought-treated plants. Our results indicate that beneficial traits among plant species in a community may be responsible for the enhanced capacity to survive drought stress. Resistance to drought may, therefore, not be linked to species richness, but rather to the nature of interaction that exists between the community members.

Otieno, Dennis; Kreyling, Juergen; Purcell, Andrew; Herold, Nadine; Grant, Kerstin; Tenhunen, John; Beierkuhnlein, Carl; Jentsch, Anke

2012-02-01

375

Impact of grazing on the species richness of plant communities in Mediterranean temporary pools (western Morocco).  

PubMed

The impact of grazing on the vegetation of Moroccan temporary pools has been studied at 2 scales: regional (inter-pools) and local (intra-pools). Half of the 16 forest pools studied is located in a reserve and ungrazed. The other half, located within public forest, is grazed. Vegetation relevés coupled to water-depths measurements were carried out in each pool. The results showed a significant effect of grazing on both scales of analysis. This effect was found in the species composition of the vegetation, which differed between the 2 types of pools, and in the lower species richness and abundance of plant species in the grazed pools. These differences are interpreted as resulting from the selection by herbivores and the differential tolerance of species to disturbance. These impacts are likely to expose certain species to local extinction by reducing their populations. PMID:20816647

Bouahim, Siham; Rhazi, Laïla; Amami, Btissam; Sahib, Nargis; Rhazi, Mouhssine; Waterkeyn, Aline; Zouahri, Abdelmjid; Mesleard, François; Muller, Serge D; Grillas, Patrick

2010-09-01

376

Signaling Networks Involving Reactive Oxygen Species and Ca2+ in Plants  

NASA Astrophysics Data System (ADS)

Although plants never evolved central information processing organs such as brains, plants have evolved distributed information processing systems and are able to sense various environmental changes and reorganize their body plan coordinately without moving. Recent molecular biological studies revealed molecular bases for elementary processes of signal transduction in plants. Though reactive oxygen species (ROS) are highly toxic substances produced through aerobic respiration and photosynthesis, plants possess ROS-producing enzymes whose activity is highly regulated by binding of Ca2+. In turn, Ca2+- permeable channel proteins activated by ROS are shown to be localized to the cell membrane. These two components are proposed to constitute a positive feedback loop to amplify cellular signals. Such molecular physiological studies should be important steps to understand information processing systems in plants and future application for technology related to environmental, energy and food sciences.

Kuchitsu, Kazuyuki

2013-01-01

377

Big hitting collectors make massive and disproportionate contribution to the discovery of plant species  

PubMed Central

Discovering biological diversity is a fundamental goal—made urgent by the alarmingly high rate of extinction. We have compiled information from more than 100 000 type specimens to quantify the role of collectors in the discovery of plant diversity. Our results show that more than half of all type specimens were collected by less than 2 per cent of collectors. This highly skewed pattern has persisted through time. We demonstrate that a number of attributes are associated with prolific plant collectors: a long career with increasing productivity and experience in several countries and plant families. These results imply that funding a small number of expert plant collectors in the right geographical locations should be an important element in any effective strategy to find undiscovered plant species and complete the inventory of the world flora.

Bebber, Daniel P.; Carine, Mark A.; Davidse, Gerrit; Harris, David J.; Haston, Elspeth M.; Penn, Malcolm G.; Cafferty, Steve; Wood, John R. I.; Scotland, Robert W.

2012-01-01

378

Species-Specific Identification from Incomplete Sampling: Applying DNA Barcodes to Monitoring Invasive Solanum Plants  

PubMed Central

Comprehensive sampling is crucial to DNA barcoding, but it is rarely performed because materials are usually unavailable. In practice, only a few rather than all species of a genus are required to be identified. Thus identification of a given species using a limited sample is of great importance in current application of DNA barcodes. Here, we selected 70 individuals representing 48 species from each major lineage of Solanum, one of the most species-rich genera of seed plants, to explore whether DNA barcodes can provide reliable specific-species discrimination in the context of incomplete sampling. Chloroplast genes ndhF and trnS-trnG and the nuclear gene waxy, the commonly used markers in Solanum phylogeny, were selected as the supplementary barcodes. The tree-building and modified barcode gap methods were employed to assess species resolution. The results showed that four Solanum species of quarantine concern could be successfully identified through the two-step barcoding sampling strategy. In addition, discrepancies between nuclear and cpDNA barcodes in some samples demonstrated the ability to discriminate hybrid species, and highlights the necessity of using barcode regions with different modes of inheritance. We conclude that efficient phylogenetic markers are good candidates as the supplementary barcodes in a given taxonomic group. Critically, we hypothesized that a specific-species could be identified from a phylogenetic framework using incomplete sampling–through this, DNA barcoding will greatly benefit the current fields of its application.

Zhang, Wei; Fan, Xiaohong; Zhu, Shuifang; Zhao, Hong; Fu, Lianzhong

2013-01-01

379

Hierarchical metapopulation dynamics of two aphid species on a shared host plant.  

PubMed

We modeled hierarchical multiscale colonization-extinction dynamics of two aphid species living in a shared host plant. We parameterized the model with data collected at the level of individual ramets of the host plant, with the plants being organized as groups within islands. As expected, the extinction rates and per capita colonization rates decreased with increasing spatial scale. The per capita colonization rates were greater for winged than for unwinged individuals, but as the unwinged individuals were much more abundant, they actually performed most of the colonizations. Colonizations and extinctions were negatively correlated, so that when the colonization rate in a given island was high, the extinction rate in the same island was low. There was a clear indication of interspecific interaction, with the presence of one species increasing the extinction rate and decreasing the colonization rate of the other species. Further simulation results based on the parameterized model show a contrasting pattern between the two species, with Metopeurum fuscoviride (with relatively stable dynamics) being favored by a highly aggregated distribution of the ramets, whereas for Macrosiphoniella tanacetaria (with a high turnover rate), an equally high persistence time follows if the plants are distributed in a segregated manner over several islands. PMID:19637939

Zheng, Chaozhi; Weisser, Wolfgang W; Härri, Simone A; Ovaskainen, Otso

2009-09-01

380

Environmental and plant community determinants of species loss following nitrogen enrichment  

USGS Publications Warehouse

Global energy use and food production have increased nitrogen inputs to ecosystems worldwide, impacting plant community diversity, composition, and function. Previous studies show considerable variation across terrestrial herbaceous ecosystems in the magnitude of species loss following nitrogen (N) enrichment. What controls this variation remains unknown. We present results from 23 N-addition experiments across North America, representing a range of climatic, soil and plant community properties, to determine conditions that lead to greater diversity decline. Species loss in these communities ranged from 0 to 65% of control richness. Using hierarchical structural equation modelling, we found greater species loss in communities with a lower soil cation exchange capacity, colder regional temperature, and larger production increase following N addition, independent of initial species richness, plant productivity, and the relative abundance of most plant functional groups. Our results indicate sensitivity to N addition is co-determined by environmental conditions and production responsiveness, which overwhelm the effects of initial community structure and composition. ?? 2007 Blackwell Publishing Ltd/CNRS.

Clark, C. M.; Cleland, E. E.; Collins, S. L.; Fargione, J. E.; Gough, L.; Gross, K. L.; Pennings, S. C.; Suding, K. N.; Grace, J. B.

2007-01-01

381

Riparian Restoration in the Southwest - Species Selection, Propagation, Planting Methods, and Case Studies1  

Microsoft Academic Search

Riparian plant communities, though small in overall area, are among the most valuable natural areas in the Southwest. The causes of degradation of southwestern riparian zones range from excessive cattle and elk grazing in montane watersheds to invasive woody exotic species and lack of natural flooding in the cottonwood forests, \\

David Dreesen; John Harrington; Tom Subirge; Pete Stewart; Greg Fenchel

382

Using in situ hyperspectral reflectance data to distinguish nine aquatic plant species  

Microsoft Academic Search

In situ hyperspectral reflectance data were studied at 50 bands (10 nm bandwidth) over the 400–900 nm spectral range to determine their potential for distinguishing among nine aquatic plant species: American lotus [Nelumbo lutea (Willd.) Pers.], American pondweed (Potamogeton nodusus Poir.), giant duckweed [Spirodela polyrrhiza (L.) Schleid.], Mexican waterlily (Nymphaea mexicana Zucc.), white waterlily (Nymphaea odorata Aiton), spatterdock [Nuphar lutea (L.) Sm.],

J. H. Everitt; C. Yang; K. R. Summy; C. S. Owens; L. M. Glomski; R. M. Smart

2011-01-01

383

Plant Species Richness in Riparian Wetlands--A Test of Biodiversity Theory  

Microsoft Academic Search

In this study, flood frequency, productivity, and spatial heterogeneity were correlated with plant species richness (SR) among wetlands on a coastal island in southeast Alaska. Studies of 16 sites in or near the Kadashan River basin demonstrated nonlinear, unimodal relations between flood frequency and SR, productivity and SR, and linear re- lations between SR and the spatial variation of flood

Michael M. Pollock; Robert J. Naiman; Thomas A. Hanley

1998-01-01

384

[Microscopic and TLC identification on the fruits of ten species plants for Umbelliferae].  

PubMed

The fruits of ten species plants of Umbelliferae, including the fruits of Peucedanum decursiyum, Saposhnikovia divaricata, Peucedanum terebinthaceun, Anethum graveolens, Cnidium monnieri, Angelica sinensis, Foeniculum vulgate, Angelica polymorpha, Ferula tunnshanica and Cicuta virosa were identified on histology and TLC. PMID:12569827

Peng, Y; Shi, J; Tan, P; Jing, X

1998-10-01

385

Cuscuta australis restrains three exotic invasive plants and benefits native species  

Microsoft Academic Search

In this study we conducted field investigations to examine the effects of native Cuscuta australis on three exotic invasive plants (i.e. Ipomoea cairica, Mikania micrantha, and Wedelia trilobata) and on the invaded native communities. The results showed that C. australis produced high infection rates on the exotic invasive hosts but low ones on the native species. Furthermore, the results showed

Hua YuJian; Jian Liu; Wei-Ming He; Shi-Li Miao; Ming Dong

2011-01-01

386

Larvicidal efficacy of five cucurbitaceous plant leaf extracts against mosquito species  

Microsoft Academic Search

Larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone, and methanol extracts of the leaf of five species\\u000a of cucurbitaceous plants, Citrullus colocynthis, Coccinia indica, Cucumis sativus, Momordica charantia, and Trichosanthes anguina, were tested against the early fourth instar larvae of Aedes aegypti L. and Culex quinquefasciatus (Say) (Diptera: Culicidae). The larval mortality was observed after 24 h of

A. Abdul Rahuman; P. Venkatesan

2008-01-01

387

Plant DNA Barcodes Can Accurately Estimate Species Richness in Poorly Known Floras  

Microsoft Academic Search

BackgroundWidespread uptake of DNA barcoding technology for vascular plants has been slow due to the relatively poor resolution of species discrimination (?70%) and low sequencing and amplification success of one of the two official barcoding loci, matK. Studies to date have mostly focused on finding a solution to these intrinsic limitations of the markers, rather than posing questions that can

Craig Costion; Andrew Ford; Hugh Cross; Darren Crayn; Mark Harrington; Andrew Lowe

2011-01-01

388

Influences of Three Plant Species on Fertility of Iron Mine Tailings Contained Vermicompost: Experiment in Greenhouse  

Microsoft Academic Search

The aim of this experiment is to test three plant species potential of growing in poor fertility and improving rhizosphere nutrient during iron mine tailings restoration. Three herbs, Zea diploperennis, Avena fatua and Lolium perenne, were cultured in pots with iron mine tailings under greenhouse. At the same time, cow manure vermicompost was applied into iron mine tailings to increase

Jun-ying Zhang; Yong-li Xu; Fu-ping Li; Dong-yun Han; Hui-jie Zheng

2011-01-01

389

Oxygen species scavenger activities and phenolic contents of four West African plants  

Microsoft Academic Search

In West Africa, Alchornea cordifolia, Baphia nitida, Cassia occidentalis and Boerhavia diffusa leaves are used in food and drinks, as well as in traditional medicine, to treat rheumatic ailments which incur oxidative stress. First, these plants were evaluated for their antioxidant properties through a scavenger effect on reactive oxygen species (ROS), such as hydrogen peroxide and hypochlorous acid. All of

G. Kouakou-Siransy; S. Sahpaz; G. Irié-Nguessan; Y. J. Datte; J. Kablan; B. Gressier; F. Bailleul

2010-01-01

390

Metal uptake by medicinal plant species grown in soils contaminated by a smelter  

Microsoft Academic Search

The hypothesis tested in this study was if medicinal plants could be grown as alternative crops in heavy metal polluted soils without contamination of the final marketable produce. Furthermore, medicinal crops may offer a phytoremediation option for mildly heavy metal polluted agricultural soils. The effect of metal-enriched soils was evaluated in five medicinal species (Bidens tripartita L., Leonurus cardiaca L.,

Valcho D. Zheljazkov; Ekaterina A. Jeliazkova; Natasha Kovacheva; Anatoli Dzhurmanski

2008-01-01

391

Identification of conservation measures to protect the Japanese endangered plant species Aster kantoensis  

Microsoft Academic Search

To identify the factors responsible for degrading the habitat of the endangered plant species Aster kantoensis, as well as the vulnerable life stage where this occurs, we carried out sowing experiments. Two natural habitats were simulated, being situated along the floodplains of the Tama River in central Japan. Seeds collected from a natural habitat were sown in two apparently suitable

Ken Inoue; Noboru Kuramoto; Masayuki Maki; Michiko Masuda; Izumi Washitani

1998-01-01

392

Factors affecting plant species composition of hedgerows: relative importance and hierarchy  

Microsoft Academic Search

Although there has been a clear quantitative and qualitative decline in traditional hedgerow network landscapes during last century, hedgerows are crucial for the conservation of rural biodiversity, functioning as an important habitat, refuge and corridor for numerous species. To safeguard this conservation function, insight in the basic organizing principles of hedgerow plant communities is needed. The vegetation composition of 511 individual

Bart Deckers; Martin Hermy; Bart Muys

2004-01-01

393

Hydraulic modelling of horizontal-subsurface flow constructed wetlands: Influence of operation time and plant species  

Microsoft Academic Search

Hydraulic behaviour is a very important aspect in the design of a constructed wetland (CW). Different hydraulic models have been widely applied to obtain a better understanding of CW flow properties and provide tools that optimise the design of constructed wetlands as wastewater treatments. This work studied the effects of the time of operation and the plant species used on

Javier Mena; José Villaseñor; Francisco J. Fernández; Rocío Gómez; Antonio De Lucas

2011-01-01

394

Why Would Plant Species Become Extinct Locally If Growing Conditions Improve?  

PubMed Central

Two assumptions underlie current models of the geographical ranges of perennial plant species: 1. current ranges are in equilibrium with the prevailing climate, and 2. changes are attributable to changes in macroclimatic factors, including tolerance of winter cold, the duration of the growing season, and water stress during the growing season, rather than to biotic interactions. These assumptions allow model parameters to be estimated from current species ranges. Deterioration of growing conditions due to climate change, e.g. more severe drought, will cause local extinction. However, for many plant species, the predicted climate change of higher minimum temperatures and longer growing seasons means, improved growing conditions. Biogeographical models may under some circumstances predict that a species will become locally extinct, despite improved growing conditions, because they are based on an assumption of equilibrium and this forces the species range to match the species-specific macroclimatic thresholds. We argue that such model predictions should be rejected unless there is evidence either that competition influences the position of the range margins or that a certain physiological mechanism associated with the apparent improvement in growing conditions negatively affects the species performance. We illustrate how a process-based vegetation model can be used to ascertain whether such a physiological cause exists. To avoid potential modelling errors of this type, we propose a method that constrains the scenario predictions of the envelope models by changing the geographical distribution of the dominant plant functional type. Consistent modelling results are very important for evaluating how changes in species areas affect local functional trait diversity and hence ecosystem functioning and resilience, and for inferring the implications for conservation management in the face of climate change.

Kramer, Koen; Bijlsma, Rienk-Jan; Hickler, Thomas; Thuiller, Wilfried

2012-01-01

395

Seed Density Significantly Affects Species Richness and Composition in Experimental Plant Communities  

PubMed Central

Studies on the importance of seed arrival for community richness and composition have not considered the number of seeds arriving and its effect on species richness and composition of natural communities is thus unknown. A series of experimental dry grassland communities were established. All communities were composed of the same 44 species in exactly the same proportions on two substrates using three different seed densities. The results showed that seed density had an effect on species richness only at the beginning of the experiment. In contrast, the effects on species composition persisted across the entire study period. The results do not support the prediction that due to higher competition for light in nutrient-rich soil, species richness will be the highest in the treatment with the lowest seed density. However, the prevalence of small plants in the lowest seed density supported the expectation that low seed density guarantees low competition under high soil nutrients. In the nutrient-poor soil, species richness was the highest at the medium seed density, indicating that species richness reflects the balance between competition and limitations caused by the availability of propagules or their ability to establish themselves. This medium seed density treatment also contained the smallest plants. The results demonstrate that future seed addition experiments need to consider the amount of seed added so that it reflects the amount of seed that is naturally found in the field. Differences in seed density, mimicking different intensity of the seed rain may also explain differences in the composition of natural communities that cannot be attributed to habitat conditions. The results also have important implications for studies regarding the consequences of habitat fragmentation suggesting that increasing fragmentation may change species compositions not only due to different dispersal abilities but also due to differential response of plants to overall seed density.

Munzbergova, Zuzana

2012-01-01

396

Molecular biology of K+ transport across the plant cell membrane: what do we learn from comparison between plant species?  

PubMed

Cloning and characterizations of plant K(+) transport systems aside from Arabidopsis have been increasing over the past decade, favored by the availability of more and more plant genome sequences. Information now available enables the comparison of some of these systems between species. In this review, we focus on three families of plant K(+) transport systems that are active at the plasma membrane: the Shaker K(+) channel family, comprised of voltage-gated channels that dominate the plasma membrane conductance to K(+) in most environmental conditions, and two families of transporters, the HAK/KUP/KT K(+) transporter family, which includes some high-affinity transporters, and the HKT K(+) and/or Na(+) transporter family, in which K(+)-permeable members seem to be present in monocots only. The three families are briefly described, giving insights into the structure of their members and on functional properties and their roles in Arabidopsis or rice. The structure of the three families is then compared between plant species through phylogenic analyses. Within clusters of ortologues/paralogues, similarities and differences in terms of expression pattern, functional properties and, when known, regulatory interacting partners, are highlighted. The question of the physiological significance of highlighted differences is also addressed. PMID:24666983

Véry, Anne-Aliénor; Nieves-Cordones, Manuel; Daly, Meriem; Khan, Imran; Fizames, Cécile; Sentenac, Hervé

2014-05-15

397

Evaluation of air pollution tolerance index of selected plant species along roadsides in Thiruvananthapuram, Kerala.  

PubMed

To develop the usefulness of plants as bioindicators requires an appropriate selection of plant species which entail an utmost importance for a particular situation. In the present study a periodic evaluation of air pollution tolerance index [APTI] of selected tree species such as Polyalthia longifolia, (Sonner) Thw., Alstonia scholaris, R. Br., Mangifera indica, L., and shrubs Clerodendron infortunatum, L., Eupatorium odoratum, L., and Hyptis suaveolens, (L.) Poit., growing adjacent to the National Highway-47 passing through Thiruvananthapuram District which lies on the south-west coast of India, was carried out with a view to find out the air pollution tolerance as well as sensitivity of the plant species during different seasons. Among the trees in the roadside areas studied, Polyalthia longifolia, (Sonner) Thw., expressed highest APTI values and proved to be a tolerant variety and the others as sensitive species to air pollutants. In the case of shrubs, Clerodendron infortunatum, L., exhibited highest APTI values (7.34) and found to be more tolerant compared to the other two shrub species studied. PMID:21047015

Jyothi, S Jissy; Jaya, D S

2010-05-01

398

Silica distribution in various bamboos species and its effects on plant growth  

NASA Astrophysics Data System (ADS)

Bamboos are distributed throughout the world’s temperate, tropical and subtropical regions. They are widely used in industry, as fresh edible shoots, paper maker, building and even in medicine. Bamboos also play multiple ecologic functions such as soil and water conservation and erosion control. Bamboos have generally high silicon (Si) content. Silicon is known to have beneficial effects on plants and alleviate various stresses. The aim of this study is to quantify the Si uptake and distribution in various bamboos species and to investigate the effects of Si on the plant growth. Two complementary studies were carried out, one under natural conditions and one under controlled conditions. First of all, we performed an inventory of Si tissue content in 16 bamboos species growing in a non-polluted tropical soil at the Reunion Island (France, Indian ocean). We determined Si content in leaf and in stem tissues sampled at several heights for each plant. One of these species Gigantocloa sp « Malay Dwarf » was grown for 3 months in nutrient solution at five Si concentrations (0, 0.25, 0.75, 1.15, 1.5 mM Si). Silica deposition was examined in leaves using a cryo-SEM equipped with EDS. The Si concentration varies significantly between species, depending on rhizome morphology. Bamboos having leptomorph rhizomes show significantly higher leaf and stem Si content than that of species having pachymorph rhizomes. The distribution of Si in the plant has the same trends for all species. Leaves are the most concentrated organs (10.9 %), and within the stem Si concentration significantly increases from the bottom (0.32%) to the top of the plant (2.1%). Plant Si content increases with the Si supply. Leaves of Gigantocloa sp « Malay Dwarf » accumulate 15.2 % of Si under natural conditions and up to 24 % when exposed to the highest Si treatment. Unlike previous studies, our experiment shows that the concentration of Si had no significant effect on nutrient uptake and biomass production. Leaf silica deposition occurs mainly in epidermal cells, micro-hairs, prickles hairs and bulliform cells. A better knowledge of Si distribution in various species and in various tissues into the plant is promising to understand the mechanisms of absorption, transportation and precipitation of Si, and thus its role on the stress tolerance.

Collin, B.; Meunier, J.; Keller, C.; Doelsch, E.; Panfili, F.

2010-12-01

399

Species-specific seed dispersal in an obligate ant-plant mutualism.  

PubMed

Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism. PMID:19194502

Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

2009-01-01

400

Species-Specific Seed Dispersal in an Obligate Ant-Plant Mutualism  

PubMed Central

Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism.

Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

2009-01-01

401

Proliferation of diversified clostridial species during biological soil disinfestation incorporated with plant biomass under various conditions.  

PubMed

Biological soil disinfestation (BSD) involves the anaerobic decomposition of plant biomass by microbial communities leading to control of plant pathogens. We analyzed bacterial communities in soil of a model experiment of BSD, as affected by biomass incorporation under various conditions, to find out the major anaerobic bacterial groups which emerged after BSD treatments. The soil was treated with Brassica juncea plants, wheat bran, or Avena strigosa plants, irrigated at 20 or 30 % moisture content and incubated at 25-30 °C for 17 days. The population of Fusarium oxysporum f. sp. spinaciae incorporated at the start of the experiment declined markedly for some BSD conditions and rather high concentrations of acetate and butyrate were detected from these BSD-treated soils. The polymerase chain reaction-denaturing gradient gel electrophoresis analysis based on the V3 region of 16S rRNA gene sequences from the soil DNA revealed that bacterial profiles greatly changed according to the treatment conditions. Based on the clone library analysis, phylogenetically diverse clostridial species appeared exceedingly dominant in the bacterial community of BSD soil incorporated with Brassica plants or wheat bran, in which the pathogen was suppressed completely. Species in the class Clostridia such as Clostridium saccharobutylicum, Clostridium acetobutylicum, Clostridium xylanovorans, Oxobacter pfennigii, Clostridium pasteurianum, Clostridium sufflavum, Clostridium cylindrosporum, etc. were commonly recognized as closely related species of the dominant clone groups from these soil samples. PMID:23132344

Mowlick, Subrata; Takehara, Toshiaki; Kaku, Nobuo; Ueki, Katsuji; Ueki, Atsuko

2013-09-01

402

The potential of Thai indigenous plant species for the phytoremediation of arsenic contaminated land.  

PubMed

To assess the potential of the native plant species for phytoremediation, plant and soil samples were collected from two areas in Thailand that have histories of arsenic pollution from mine tailings. The areas were the Ron Phibun District (Nakorn Si Thammarat province) and Bannang Sata District (Yala province), and samples were taken in 1998 and 1999 and analysed for total arsenic by atomic absorption spectrophotometry. Arsenic concentrations in soil ranged from 21 to 14,000 microg g(-1) in Ron Phibun, and from 540 to 16,000 microg g(-1) in Bannang Sata. The criteria used for selecting plants for phytoremediation were: high As tolerance, high bioaccumulation factor, short life cycle, high propagation rate, wide distribution and large shoot biomass. Of 36 plant species, only two species of ferns (Pityrogramma calomelanos and Pteris vittata), a herb (Mimosa pudica), and a shrub (Melastoma malabrathricum), seemed suitable for phytoremediation. The ferns were by far the most proficient plants at accumulating arsenic from soil, attaining concentrations of up to 8350 microg g(-1) (dry mass) in the frond. PMID:12009144

Visoottiviseth, P; Francesconi, K; Sridokchan, W

2002-01-01

403

Divergence in Defence against Herbivores between Males and Females of Dioecious Plant Species  

PubMed Central

Defensive traits may evolve differently between sexes in dioecious plant species. Our current understanding of this process hinges on a partial view of the evolution of resistance traits that may result in male-biased herbivory in dioecious populations. Here, we present a critical summary of the current state of the knowledge of herbivory in dioecious species and propose alternative evolutionary scenarios that have been neglected. These scenarios consider the potential evolutionary and functional determinants of sexual dimorphism in patterns of resource allocation to reproduction, growth, and defence. We review the evidence upon which two previous reviews of sex-biased herbivory have concluded that male-biased herbivory is a rule for dioecious species, and we caution readers about a series of shortcomings of many of these studies. Lastly, we propose a min