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Sample records for agrostis grass species

  1. Intake characteristics of grass species from semi-natural pastures in the United Kingdom

    Science.gov (United States)

    Four grass species (Lolium perenne L., Holcus lanatus L. cv Glen, Agrostis stolonifera L. cv Kromi, and Poa trivialis L.) commonly found in mesotropic lowland semi-natural grassland communities in the UK were sown in boxes (85 x 44 x 14 cm) to create micro-swards. Once established, the micro-sward...

  2. An evaluation of the use of individual grass species in retaining polluted soil and dust particulates in vegetated sustainable drainage devices.

    Science.gov (United States)

    Charlesworth, S M; Bennett, J; Waite, A

    2016-08-01

    A sustainable means of preventing polluted particulates carried in urban storm water entering rivers, groundwater and lakes is by employing vegetated sustainable drainage system (SUDS) devices, or best management practices to trap or biodegrade them. In the UK, a mixture of grass species is recommended for use in devices such as swales or filter strips. However, there is little evidence in support of the efficiency of the individual grasses or mixtures to deal with such contaminated material. A pot-based pollutant retention study was conducted using processed street dust from central Coventry, UK, as a simulated pollutant to be applied in different quantities to a variety of recommended grasses for vegetated SUDS devices. Analysis was conducted on compost cores, roots and shoots for heavy metals (Cd, Cu, Ni, Pb and Zn). Street dust mainly concentrated in the top compost layer for all grasses with only the finer material migrating down the profile. Analysis of roots indicated little accumulation, with ANOVA statistical tests indicating significant differences in heavy metal concentrations, with less in the compost and more in the shoots. Development of root systems on or near the surface possibly explains increased uptake of heavy metals by some species. Overall Agrostis canina and Poa pratensis showed the greatest accumulations compared to their controls although Agrostis capillaris syn.tenuis and Agrostis stolonifera also demonstrated accumulation potential. On ranking, Agrostis canina and Poa pratensis were highest overall. These rankings will assist in selecting the best grasses to address pollution of the urban environment by contaminated particulates.

  3. An evaluation of the use of individual grass species in retaining polluted soil and dust particulates in vegetated sustainable drainage devices.

    Science.gov (United States)

    Charlesworth, S M; Bennett, J; Waite, A

    2016-08-01

    A sustainable means of preventing polluted particulates carried in urban storm water entering rivers, groundwater and lakes is by employing vegetated sustainable drainage system (SUDS) devices, or best management practices to trap or biodegrade them. In the UK, a mixture of grass species is recommended for use in devices such as swales or filter strips. However, there is little evidence in support of the efficiency of the individual grasses or mixtures to deal with such contaminated material. A pot-based pollutant retention study was conducted using processed street dust from central Coventry, UK, as a simulated pollutant to be applied in different quantities to a variety of recommended grasses for vegetated SUDS devices. Analysis was conducted on compost cores, roots and shoots for heavy metals (Cd, Cu, Ni, Pb and Zn). Street dust mainly concentrated in the top compost layer for all grasses with only the finer material migrating down the profile. Analysis of roots indicated little accumulation, with ANOVA statistical tests indicating significant differences in heavy metal concentrations, with less in the compost and more in the shoots. Development of root systems on or near the surface possibly explains increased uptake of heavy metals by some species. Overall Agrostis canina and Poa pratensis showed the greatest accumulations compared to their controls although Agrostis capillaris syn.tenuis and Agrostis stolonifera also demonstrated accumulation potential. On ranking, Agrostis canina and Poa pratensis were highest overall. These rankings will assist in selecting the best grasses to address pollution of the urban environment by contaminated particulates. PMID:26753553

  4. Long-term persistence of seeded grass species: an unwanted side effect of ecological restoration.

    Science.gov (United States)

    Rydgren, Knut; Auestad, Inger; Hamre, Liv Norunn; Hagen, Dagmar; Rosef, Line; Skjerdal, Gudrun

    2016-07-01

    Spoil heaps are the visible footprint of hydropower production, particularly in vulnerable alpine environments. Speeding up vegetation development by seeding commercial grass species has been a common restoration practice for the last 50 years, but we lack information on whether seeded species decline and allow native plant cover to develop. We visually estimated cover of native vascular plants and five seeded grass species (Agrostis capillaris, Festuca ovina, Festuca rubra, Schedonorus pratensis and Phleum pratense) on eight spoil heaps at different elevations (boreal-alpine zone) in western Norway. Spoil heap vegetation was censused twice (9-20 and 24-36 years after spoil heap construction); the undisturbed surrounding vegetation was also censused on the second occasion. Total cover on the spoil heaps showed some increase, but remained far below that in surrounding areas. Cover of seeded grass species in the surroundings was low (but not negligible), indicating suboptimal establishment ability. Seeded species usually covered less than 20 % of the spoil heaps, and only F. rubra, F. ovina and A. capillaris contributed substantially. Proportional cover indicated better initial establishment by seeded species, but their cover decreased between the censuses on all but the highest located spoil heap. The persistence of seeded grass species is problematic, and despite the decrease in proportional cover, they are likely to persist for decades on spoil heaps, posing a risk of invasion of surrounding areas. We therefore recommend replacing the practice of seeding with more appropriate restoration measures.

  5. Soil microorganisms alleviate the allelochemical effects of a thyme monoterpene on the performance of an associated grass species.

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    Bodil K Ehlers

    Full Text Available BACKGROUND: Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. METHODOLOGY/PRINCIPAL FINDINGS: To explore if the allelopathic effects on a grass by the common thyme monoterpene "carvacrol" are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms or not (soil microorganisms present in soil. The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. CONCLUSIONS/SIGNIFICANCE: The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions.

  6. Comparative genome analysis between Agrostis stolonifera and members of the Pooideae subfamily, including Brachypodium distachyon.

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    Loreto Araneda

    Full Text Available Creeping bentgrass (Agrostis stolonifera, allotetraploid 2n = 4x = 28 is one of the major cool-season turfgrasses. It is widely used on golf courses due to its tolerance to low mowing and aggressive growth habit. In this study, we investigated genome relationships of creeping bentgrass relative to the Triticeae (a consensus map of Triticum aestivum, T. tauschii, Hordeum vulgare, and H. spontaneum, oat, rice, and ryegrass maps using a common set of 229 EST-RFLP markers. The genome comparisons based on the RFLP markers revealed large-scale chromosomal rearrangements on different numbers of linkage groups (LGs of creeping bentgrass relative to the Triticeae (3 LGs, oat (4 LGs, and rice (8 LGs. However, we detected no chromosomal rearrangement between creeping bentgrass and ryegrass, suggesting that these recently domesticated species might be closely related, despite their memberships to different Pooideae tribes. In addition, the genome of creeping bentgrass was compared with the complete genome sequence of Brachypodium distachyon in Pooideae subfamily using both sequences of the above-mentioned mapped EST-RFLP markers and sequences of 8,470 publicly available A. stolonifera ESTs (AgEST. We discovered large-scale chromosomal rearrangements on six LGs of creeping bentgrass relative to B. distachyon. Also, a total of 24 syntenic blocks based on 678 orthologus loci were identified between these two grass species. The EST orthologs can be utilized in further comparative mapping of Pooideae species. These results will be useful for genetic improvement of Agrostis species and will provide a better understanding of evolution within Pooideae species.

  7. Mycorrhizas effects on nutrient interception in two riparian grass species

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    Hamid Reza Asghari

    2014-12-01

    Full Text Available Effects of arbuscular mycorrhizal (AM fungi on plant growth and soil nutrient depletion are well known, but their roles as nutrient interceptor in riparian areas are less clear. The effects of AM fungi on growth, soil nutrient depletion and nutrient leaching were investigated in columns with two riparian grass species. Mycorrhizal and non mycorrhizal (NM plants were grown in a mixture of riparian soil and sand (60% and 40%, w/w respectively for 8 weeks under glasshouse conditions. Mycorrhizal colonization, AM external hyphae development, plant growth, nutrient uptake and NO3, NH4 and available P in soil and leachate were measured. Mycorrhizal fungi highly colonized roots of exotic grass Phalaris aquatica and significantly increased plant growth and nutrient uptake. Columns containing of AM Phalaris aquatica had higher levels of AM external hyphae, lower levels of NO3, NH4 and available P in soil and leachate than NM columns. Although roots of native grass Austrodanthonia caespitosa had moderately high levels of AM colonization and AM external hyphae in soil, AM inoculation had no significant effects on plant growth, soil and leachate concentration of NO3 and NH4. But AM inoculation decreased available soil P concentration in deeper soil layer and had no effects on dissolved P in leachate. Although both grass species had nearly the same biomass, results showed that leachate collected from Austrodanthonia caespitosa columns significantly had lower levels of NO3, NH4 and dissolve P than leachate from exotic Phalaris aquatica columns. Taken together, these data shows that native plant species intercept higher nutrient than exotic plant species and had no responsiveness to AM fungi related to nutrient leaching, but AM fungi play an important role in interception of nutrient in exotic plant species.

  8. Mycorrhizas effects on nutrient interception in two riparian grass species

    OpenAIRE

    Hamid Reza Asghari; Timothy Richard Cavagnaro

    2014-01-01

    Effects of arbuscular mycorrhizal (AM) fungi on plant growth and soil nutrient depletion are well known, but their roles as nutrient interceptor in riparian areas are less clear. The effects of AM fungi on growth, soil nutrient depletion and nutrient leaching were investigated in columns with two riparian grass species. Mycorrhizal and non mycorrhizal (NM) plants were grown in a mixture of riparian soil and sand (60% and 40%, w/w respectively) for 8 weeks under glasshouse conditions. Mycorrhi...

  9. Responses of three grass species to creosote during phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Huang Xiaodong; El-Alawi, Yousef; Penrose, Donna M.; Glick, Bernard R.; Greenberg, Bruce M

    2004-08-01

    Phytoremediation of creosote-contaminated soil was monitored in the presence of Tall fescue, Kentucky blue grass, or Wild rye. For all three grass species, plant growth promoting rhizobacteria (PGPR) were evaluated for plant growth promotion and protection of plants from contaminant toxicity. A number of parameters were monitored including plant tissue water content, root growth, plant chlorophyll content and the chlorophyll a/b ratio. The observed physiological data indicate that some plants mitigated the toxic effects of contaminants. In addition, in agreement with our previous experiments reported in the accompanying paper (Huang, X.-D., El-Alawi, Y., Penrose, D.M., Glick, B.R., Greenberg, B.M., 2004. A multi-process phytoremediation system for removal of polycyclic aromatic hydrocarbons from contaminated soil. Environ. Poll. doi: 10.1016/j.envpol.2003.09.031), PGPR were able to greatly enhance phytoremediation. PGPR accelerated plant growth, especially roots, in heavily contaminated soils, diminishing the toxic effects of contaminants to plants. Thus, the increased root biomass in PGPR-treated plants led to more effective remediation. - Plant growth promoting rhizobacteria enhanced growth and remediation of three grass species.

  10. Root lifespans of four grass species from habitats differing in nutrient availability

    NARCIS (Netherlands)

    Krift, van der T.A.J.; Berendse, F.

    2002-01-01

    1. In grass species that occur in pastures or hay meadows, life spans of roots determine much of the carbon and nutrient loss from the plant in addition to the amounts that are lost by mowing or grazing. We hypothesized that grass species from nutrient-poor habitats had longer root life spans and co

  11. Retrotranspositions in orthologous regions of closely related grass species

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    Swigoňová Zuzana

    2006-08-01

    Full Text Available Abstract Background Retrotransposons are commonly occurring eukaryotic transposable elements (TEs. Among these, long terminal repeat (LTR retrotransposons are the most abundant TEs and can comprise 50–90% of the genome in higher plants. By comparing the orthologous chromosomal regions of closely related species, the effects of TEs on the evolution of plant genomes can be studied in detail. Results Here, we compared the composition and organization of TEs within five orthologous chromosomal regions among three grass species: maize, sorghum, and rice. We identified a total of 132 full or fragmented LTR retrotransposons in these regions. As a percentage of the total cumulative sequence in each species, LTR retrotransposons occupy 45.1% of the maize, 21.1% of the rice, and 3.7% of the sorghum regions. The most common elements in the maize retrotransposon-rich regions are the copia-like retrotransposons with 39% and the gypsy-like retrotransposons with 37%. Using the contiguous sequence of the orthologous regions, we detected 108 retrotransposons with intact target duplication sites and both LTR termini. Here, we show that 74% of these elements inserted into their host genome less than 1 million years ago and that many retroelements expanded in size by the insertion of other sequences. These inserts were predominantly other retroelements, however, several of them were also fragmented genes. Unforeseen was the finding of intact genes embedded within LTR retrotransposons. Conclusion Although the abundance of retroelements between maize and rice is consistent with their different genome sizes of 2,364 and 389 Mb respectively, the content of retrotransposons in sorghum (790 Mb is surprisingly low. In all three species, retrotransposition is a very recent activity relative to their speciation. While it was known that genes re-insert into non-orthologous positions of plant genomes, they appear to re-insert also within retrotransposons, potentially

  12. Establishment and growth of experimental grass species mixtures on coal mine sites reclaimed with municipal biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Halofsky, J.E.; McCormick, L.H. [Penn State University, University Park, PA (US). School for Forest Resources

    2005-05-01

    The Surface Mining Control and Reclamation Act of 1977 requires that coal mine sites in the United States be reclaimed to establish vegetative cover that is diverse, native, and capable of plant succession. However, there is a question as to whether vegetation established on coal mine sites reclaimed with biosolids is diverse and capable of plant succession. The influx of nutrients with the addition of biosolids leads to long-term dominance by early-successional species, most notably grasses, and consequently, a low establishment of woody and volunteer species. Additionally, many grass species commonly planted in reclamation have aggressive growth habits that lead to their dominance in coal mine plant communities. The establishment and growth of selected grass mixes was evaluated to determine whether alternative grass mixes would be less competitive with woody and volunteer species as compared to commonly used grass mixes. Percent vegetative cover, species richness, and the survival of direct-seeded woody species were assessed for each treatment grass mixture. It was found that Poa compress and a mixture of P. compress, Panicum virgatum, and Trifolium repens provided adequate coverage while still allowing the highest species richness and survival of woody species. Use of these species mixtures in coal mine reclamation with biosolids in the eastern United States would likely lead to establishment of a more species-rich plant community with a greater woody species component while still providing erosion control and site protection.

  13. Establishment and growth of experimental grass species mixtures on coal mine sites reclaimed with municipal biosolids.

    Science.gov (United States)

    Halofsky, Jessica E; McCormick, Larry H

    2005-05-01

    The Surface Mining Control and Reclamation Act of 1977 requires that coal mine sites in the United States be reclaimed to establish vegetative cover that is diverse, native, and capable of plant succession. However, there is a question as to whether vegetation established on coal mine sites reclaimed with biosolids is diverse and capable of plant succession. The influx of nutrients with the addition of biosolids leads to long-term dominance by early-successional species, most notably grasses, and consequently, a low establishment of woody and volunteer species. Additionally, many grass species commonly planted in reclamation have aggressive growth habits that lead to their dominance in coal mine plant communities. The establishment and growth of selected grass mixes was evaluated to determine whether alternative grass mixes would be less competitive with woody and volunteer species as compared to commonly used grass mixes. Percent vegetative cover, species richness, and the survival of direct-seeded woody species were assessed for each treatment grass mixture. It was found that Poa compressa and a mixture of P. compressa, Panicum virgatum, and Trifolium repens provided adequate coverage while still allowing the highest species richness and survival of woody species. Use of these species mixtures in coal mine reclamation with biosolids in the eastern United States would likely lead to establishment of a more species-rich plant community with a greater woody species component while still providing erosion control and site protection. PMID:15920668

  14. DISTRIBUTION AND DIVERSITY OF FUSARIUM SPECIES ASSOCIATED WITH GRASSES IN TEN STATES THROUGHOUT PENINSULAR MALAYSIA

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    NUR AIN IZZATI, M.Z

    2009-01-01

    Full Text Available Fusarium is one of the important genera associated with grasses as saprophytes, endophytes and pathogens. A study was carried out on distribution and diversity of Fusarium species associated with two groups of grasses in 10 states throughout Peninsular Malaysia i.e. agricultural grasses (Oryza sativa and Saccharum officinarum and non-agricultural grasses (Axonopus compressus, Centhotheca lappacea, Chloris barbata, Crysopogon aciculatus, Cyanadon dactylon, Dactyloctenium aegyptium, Digitaria ciliaris, Echinochloa colona, Eleusine indica, Eragrostis amabilis, Eragrostis malayana, Eragrostis uniloides, Ischaemum magnum, Panicum brevifolium, Panicum millaneum, Panicum repens, Paspalum commersonii, Paspalum conjugatum, Paspalum orbiculare, Pennisetum purpureum, Sacciolepis indica, Sporobolus diander and Sporobolus indicus. A total of 474 isolates were single-spored and identified by morphological characteristics. F. semitectum was frequently isolated (23.6%, followed by F. sacchari and F. fujikuroi with 15.4% and 14.6%, respectively. The other nine species were F. solani (10.3%, F. proliferatum (8.9%, F. oxysporum (7.4%, F. subglutinans (6.5%, F. equiseti (5.5%, F. verticillioides (3.4%, F. compactum (2.5%, F. chlamydosporum (1.1% and F. longipes (0.8%. Based on the Shannon-Weiner Index, F. solani was the highest (H' = 2.62 isolated from grasses. Species of Fusarium from O. sativa were widely diverse with 11 species, followed by non-agricultural grasses with nine species and S. officinarum with only six species. This is the first report on diversity of Fusarium associated with grasses in Malaysia.

  15. Dichotomy in the NRT gene families of dicots and grass species.

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    Darren Plett

    Full Text Available A large proportion of the nitrate (NO(3(- acquired by plants from soil is actively transported via members of the NRT families of NO(3(- transporters. In Arabidopsis, the NRT1 family has eight functionally characterised members and predominantly comprises low-affinity transporters; the NRT2 family contains seven members which appear to be high-affinity transporters; and there are two NRT3 (NAR2 family members which are known to participate in high-affinity transport. A modified reciprocal best hit (RBH approach was used to identify putative orthologues of the Arabidopsis NRT genes in the four fully sequenced grass genomes (maize, rice, sorghum, Brachypodium. We also included the poplar genome in our analysis to establish whether differences between Arabidopsis and the grasses may be generally applicable to monocots and dicots. Our analysis reveals fundamental differences between Arabidopsis and the grass species in the gene number and family structure of all three families of NRT transporters. All grass species possessed additional NRT1.1 orthologues and appear to lack NRT1.6/NRT1.7 orthologues. There is significant separation in the NRT2 phylogenetic tree between NRT2 genes from dicots and grass species. This indicates that determination of function of NRT2 genes in grass species will not be possible in cereals based simply on sequence homology to functionally characterised Arabidopsis NRT2 genes and that proper functional analysis will be required. Arabidopsis has a unique NRT3.2 gene which may be a fusion of the NRT3.1 and NRT3.2 genes present in all other species examined here. This work provides a framework for future analysis of NO(3(- transporters and NO(3(- transport in grass crop species.

  16. Evolutionary relationships between Rhynchosporium lolii sp. nov. and other Rhynchosporium species on grasses.

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    Kevin M King

    Full Text Available The fungal genus Rhynchosporium (causative agent of leaf blotch contains several host-specialised species, including R. commune (colonising barley and brome-grass, R. agropyri (couch-grass, R. secalis (rye and triticale and the more distantly related R. orthosporum (cocksfoot. This study used molecular fingerprinting, multilocus DNA sequence data, conidial morphology, host range tests and scanning electron microscopy to investigate the relationship between Rhynchosporium species on ryegrasses, both economically important forage grasses and common wild grasses in many cereal growing areas, and other plant species. Two different types of Rhynchosporium were found on ryegrasses in the UK. Firstly, there were isolates of R. commune that were pathogenic to both barley and Italian ryegrass. Secondly, there were isolates of a new species, here named R. lolii, that were pathogenic only to ryegrass species. R. lolii was most closely related to R. orthosporum, but exhibited clear molecular, morphological and host range differences. The species was estimated to have diverged from R. orthosporum ca. 5735 years before the present. The colonisation strategy of all of the different Rhynchosporium species involved extensive hyphal growth in the sub-cuticular regions of the leaves. Finally, new species-specific PCR diagnostic tests were developed that could distinguish between these five closely related Rhynchosporium species.

  17. Advanced analysis of dry-weight-rank data to discriminate direct and indirect interactions between white clover and grasses in a multi-species pasture under a range of management strategies

    NARCIS (Netherlands)

    Schulte, R.P.O.; Neuteboom, J.H.

    2002-01-01

    Infestations of pastures by species, such as creeping bentgrass (Agrostis stolonifera), may compromise the white clover (Trifolium repens) content in perennial ryegrass (Lolium perenne) mixtures. However, the interactions between white clover and species other than perennial ryegrass are not well un

  18. Effects of species diversity on seasonal variation in herbage yield and nutritive value of seven binary grass-legume mixtures and pure grass under cutting

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2016-01-01

    Intensively managed sown temperate grasslands are generally of low species diversity, although swards based on grass-legume mixtures may have superior productivity and herbage quality than grass-only swards. We conducted a cutting experiment over two years to test the effect of species compositio....... Results are discussed in terms of their potential to contribute to forage resources in farming practice and enhance resource use efficiency and ecosystem services....

  19. Comparison of phytoremediation potential of three grass species in soil contaminated with cadmium

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    Gołda Sylwia

    2016-03-01

    Full Text Available The aim of the study was to compare the toleration of Poa pratensis, Lolium perenne and Festuca rubra to cadmium contamination as well as the phytoremediation potential of these three species of grass. The pot experiment was conducted in four replications in pots containing 2.0 kg of soil. The soil was contaminated with three doses of Cd – 30, 60 and 120 mg·kg−1. After two months, the aerial parts of plants were harvested. The roots were dug up, brushed off from the remaining soil and washed with water. The biomass was defined and the cadmium concentration was determined in aerial parts and roots. The phytoremediation potential of grasses was evaluated using biomass of grasses, bioaccumulation factor (BF and translocation factor (TF. All three tested species of grasses had TF 1. It indicates their suitability for phytostabilisation and makes them unsuitable for phytoextraction of Cd from the soil. Comparing the usefulness of the tested grasses for phytoremediation has shown that the phytostabilisation potential of P. pratensis was lower than that of L. perenne and F. rubra. P. pratensis was distinguished by higher TF, smaller root biomass and lower tolerance for Cd excess in the soil in comparison with the two other test grasses. At the same time, L. perenne was characterised by the smallest decrease in biomass and the largest Cd accumulation in roots at the lowest dose of Cd. It indicates good usefulness for phytostabilisation of soils characterised by a relatively small pollution by cadmium.

  20. Alley cropping of legumes with grasses as forages : Effect of different grass species and row spacing of gliricidia on the growth and biomass production of forages

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    Siti Yuhaeni

    1998-12-01

    Full Text Available A study to evaluate the effect of different grass species and row spacing of gliricidia (Gliricidia sepium on the growth and biomass production of forages in an alley cropping system was conducted in two different agroclimatical zones i.e. Bogor, located at 500 m a .s .l . with an average annual rainfall of 3,112 nun/year and Sukabumi located at 900 m a .s .l . with an average annual rainfall of 1,402 mm/year . Both locations have low N, P, and K content and the soil is classified as acidic. The experimental design used was a split plot design with 3 replicates . The main plots were different grass species i.e. king grass (Pennisetum purpureum x P. typhoides and elephant grass (P. purpureum. The sub plots were the row spacing of gliricidia at 2, 3, 4, 6 m (1 hedgerows and 4 m (2 hedgerows. The results indicated that the growth and biomass production of grasses were significantly affected (P<0 .05 by the treatments in Bogor. The highest biomass productions was obtained from the 2 m row spacing which gave the highest dry matter production of grasses (1 .65 kg/hill and gliricidia (0 .086 kg/tree . In Sukabumi the growth and biomass production of grasses and gliricidia were also significantly affected by the treatments . The highest dry matter production was obtained with 2 m row spacing (dry matter of grasses and gliricidia were 1 .12 kg/hill and 0 .026 kg/tree, respectively . The result further indicated that biomass production of forages increased with the increase in gliricidia population. The alley cropping system wich is suitable for Bogor was the 2 m row spacing of gliricidia intercropped with either king or elephant grass and for Sukabumi 2 and 4 m (2 rows of gliricidia row spacing intercropped with king or elephant grass .

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

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    Gubsch, M.; Buchmann, N.; Schmid, B.; Schulze, E.; Lipowsky, A.; Roscher, C.

    2011-01-01

    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 e...

  2. Assessing veld condition in the Kruger National Park using key grass species

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    W.S.W. Trollope

    1989-10-01

    Full Text Available Veld condition refers to the condition of the vegetation in relation to some functional characteristic. In the Kruger National Park important functional characteristics are the potential of the veld to produce grass forage and fuel and to resist soil erosion. Consequently a simplified technique based on 18 key grass species was developed for assessing veld conditon and monitoring the effects of wild life management practices like veld burning, development of watering points and culling. The technique has been specifically developed for use by wildlife managers and has the ability to indicate the potential of the veld to support bulk grazing animals, to carry a fire and to resist soil erosion.

  3. Within-species variation in grass weeds in Sweden

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    Espeby Åkerblom, Liv

    2010-01-01

    Variation within a weed species enables it to persist through varying conditions and is thus an important component of weediness. In this thesis, intra-specific variation in two agronomically important attributes - herbicide susceptibility and seed dormancy - are studied in Swedish Apera spica-venti (L.) Beauv. and Alopecurus myosuroides Huds., both serious annual weeds in winter cereals, and with many cases of herbicide resistance. Swedish Elymus repens (L.) Gould, a perennial, rhizomatous g...

  4. Control of one invasive plant species allows exotic grasses to become dominant in northern Great Plains grasslands

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    Larson, D.L.; Larson, J.L.

    2010-01-01

    Decline of leafy spurge (Euphorbia esula) in the northern Great Plains of the US is generally viewed as a success story for biological control, but quality of the vegetation that survived the infestation is key to recovery of ecosystem function. In addition, effects of other invasive species, notably cool-season exotic grasses, must be taken into account. Objectives of this study were (1) to evaluate direction and significance of changes in biomass of native and exotic grasses, forbs, and leafy spurge and in plant species composition following control of leafy spurge by flea beetles and (2) to evaluate the relative effects of leafy spurge and exotic grasses on biomass of native grasses, biomass of forbs, and richness of native species. We monitored species composition (1998-2003 and 2008) and biomass (2000, 2002, 2003 and 2008) of these groups on spurge-infested and noninfested permanent plots at three sites with unbroken prairie sod in North Dakota, USA. We found little evidence, in terms of species richness or biomass of native grasses or forbs, that leafy spurge was being replaced by desirable native species, although desirable as well as weedy and exotic species were characteristic of 2008 vegetation at all three sites. Structural equation models revealed that leafy spurge had temporally intermittent negative effects on forb biomass and species richness, but no effects on native grasses. In contrast, exotic grass had consistently strong, negative effects on native grass biomass, as well as stronger negative effects than leafy spurge on native species richness. Although substantial native plant diversity remains at these sites, exotic grasses pose an important threat to these crucial building blocks of native prairie ecosystems. ?? 2010.

  5. The effect of nitrogen and glyphosate on survival and colonisation of perennial grass species in an agro-ecosystem: does the relative importance of survival decrease with competitive ability?

    Directory of Open Access Journals (Sweden)

    Christian Damgaard

    Full Text Available The ecological success of a plant species is typically described by the observed change in plant abundance or cover, but in order to more fully understand the fundamental plant ecological processes, it is necessary to inspect the underlying processes of survival and colonization and how they are affected by environmental conditions. A general ecological hypothesis on the effect of environmental gradients on demographic parameters is proposed and tested. The hypothesis is that decreasing fitness or competitive ability along an environmental gradient is associated with an increasing importance of survival for regulating the abundance of the species. The tested hypothesis is related to both the stress gradient hypothesis and whether the importance of competition increases along productivity gradients. The combined effect of nitrogen and glyphosate on the survival and colonization probability of two perennial grass species, Festuca ovina and Agrostis capillaris, which are known to differ in their responses to both glyphosate and nitrogen treatments, is calculated using pin-point cover data in permanent frames. We found that the relative importance of survival increased with the level of glyphosate for the glyphosate sensitive A. capillaris and decreased for the glyphosate tolerant F. ovina. Likewise, increasing levels of nitrogen increased the importance of survival for the relative nitrophobic F. ovina. Consequently, the proposed hypothesis was corroborated in this specific study. The proposed method will enable predictions of the effects of agricultural practices on community dynamics in a relatively simple setup eliminating the need to quantify all the interaction among the species in the plant community. The method will be immediately useful for the regulation of non-cultivated buffer strips between agricultural fields and semi-natural and natural biotopes such as hedgerows and waterways.

  6. The effect of nitrogen and glyphosate on survival and colonisation of perennial grass species in an agro-ecosystem: does the relative importance of survival decrease with competitive ability?

    Science.gov (United States)

    Damgaard, Christian; Strandberg, Beate; Mathiassen, Solvejg K; Kudsk, Per

    2013-01-01

    The ecological success of a plant species is typically described by the observed change in plant abundance or cover, but in order to more fully understand the fundamental plant ecological processes, it is necessary to inspect the underlying processes of survival and colonization and how they are affected by environmental conditions. A general ecological hypothesis on the effect of environmental gradients on demographic parameters is proposed and tested. The hypothesis is that decreasing fitness or competitive ability along an environmental gradient is associated with an increasing importance of survival for regulating the abundance of the species. The tested hypothesis is related to both the stress gradient hypothesis and whether the importance of competition increases along productivity gradients. The combined effect of nitrogen and glyphosate on the survival and colonization probability of two perennial grass species, Festuca ovina and Agrostis capillaris, which are known to differ in their responses to both glyphosate and nitrogen treatments, is calculated using pin-point cover data in permanent frames. We found that the relative importance of survival increased with the level of glyphosate for the glyphosate sensitive A. capillaris and decreased for the glyphosate tolerant F. ovina. Likewise, increasing levels of nitrogen increased the importance of survival for the relative nitrophobic F. ovina. Consequently, the proposed hypothesis was corroborated in this specific study. The proposed method will enable predictions of the effects of agricultural practices on community dynamics in a relatively simple setup eliminating the need to quantify all the interaction among the species in the plant community. The method will be immediately useful for the regulation of non-cultivated buffer strips between agricultural fields and semi-natural and natural biotopes such as hedgerows and waterways.

  7. Morphometric Variations in Caryopses and Seedlings of Two Grass Species Growing Under Contrasting Habitats

    Directory of Open Access Journals (Sweden)

    Dhara GANDHI

    2015-09-01

    Full Text Available Urochondra setulosa grows in marine conditions, while Sporobolus indicus grows near fresh water and sometimes also close to moist places along roadside areas. Both species belong to the same tribe and same family. The two grass species growing under different habitats showed characteristic variations in their morphometric traits of the caryopsis and seedlings. U. setulosa growing in salty area had characteristic features, e.g. leaf and culm with salt deposition, rigid leaf blade with pointed leaf tip, while S. indicus growing near fresh water showed glabrous nodes and internodes. Morphometric analysis of caryopses of both species showed very similar features, without prominent differences in their length, breadth and thickness. But light microscopy and scanning electron microscopic (SEM studies showed variations. Under light microscopy, features like colour, shape and compression of caryopses showed differences among the species. SEM studies of caryopses revealed a reticulate type of pattern of sculpturing on both dorsal and ventral surfaces, whereas anticlinal and periclinal walls in U. setulosa were elevated with folded walls, while in S. indicus had non elevated undulating walls. In conclusion, each individual grass ecotype evolves some characteristic morphological features to thrive well under a particular environment. Both species studied hereby, grown in different habitats, showed remarkable differentiations in their characters, thus indicating that habitats play a major role in traits of the plant growth.

  8. Degradation of Bermuda and Orchard Grass by Species of Ruminal Bacteria

    OpenAIRE

    Akin, Danny E.; Rigsby, Luanne L.

    1985-01-01

    Fiber degradation in Bermuda grass and orchard grass was evaluated gravimetrically and by scanning and transmission electron microscopy after incubation with pure cultures of rumen bacteria. Lachnospira multiparus D-32 was unable to degrade plant cell wall components. Butyrivibrio fibrisolvens 49 degraded 6 and 14.9% of the fiber components in Bermuda grass and orchard grass, respectively, and Ruminococcus albus 7 degraded 11.4% orchard grass fiber but none in Bermuda grass. Both B. fibrisolv...

  9. Allelopathic activity of some grass species on Phleum pratense seed germination subject to their density

    Directory of Open Access Journals (Sweden)

    Halina Lipińska

    2012-12-01

    Full Text Available Efficient utilization of allelopathy in the agricultural practice requires searching for some species and developmental stages when the allelopathic substances are generated in bioactive concentrations. That also requires the knowledge of allelopathy mechanisms and primarily its separation from the other aspects of plant activity, mainly from competition for environmental resources. This task, however, has remained vital in the studies on plant interference, being extremely difficult to perform under field conditions. Therefore, the studies were conducted in the laboratory. To determine the activity of an allelopathic agent of the selected grass species, the density dependent phytotoxicity model was employed. The model is based on the fact that an increase of acceptor plants density evokes a decrease of their response to the allelopathic compounds, whereas the negative effects of the competition become more intense. A higher rate of acceptor plants growth accompanying their density increase in the given object does not agree with the competition rules and thus, it may imply an allelopathic background of the observed changes. In the presented studies, the allelopathic properties of grasses - donors were evaluated by studying the effect of two densities of the emerging seeds and two- and four weeks aged seedlings of F. arundinacea, L. multiflorum, L. perenne and P. pratensis. The tested species - acceptor Ph. pratensis was sown in the density of 10 and 20 seeds in a pan. The results revealed that the germination of acceptor seeds was differentiated depending on their density in the pan, and on the species, density and the age of the donor. Inhibition of Ph. pratense seed germination in objects with a lover density may prove allelopathic effects of the studied donor grasses.

  10. Invasive species in the flora of the Starobilsk grass-meadow steppe (Ukraine

    Directory of Open Access Journals (Sweden)

    Kucher Oksana O.

    2015-06-01

    Full Text Available The results of an investigation of the invasive species in the flora of the Starobilsk grass-meadow steppe are presented. Check-list of alien plant has over 386 species of vascular plants of which 28 species are invasive. We have identified 6 transformer species from the invasive plants. We aggregate data on the entry, distribution history, ecology, occurrence in different plant communities, degree of their naturalization and the habitats where they occur. The leading families of invasive species are: Asteraceae. The basis for this group is presented by origin from the North America and the Mediterranean. With respect to the time of immigration, most of them are kenophytes. By the method of introduction, ksenophytes are dominated; according to the degree of naturalization epoecophytes and agriophytes dominate in this group. With regard to the characteristics of life forms, half of invasive species are terophytes. The vast majority of plants are heliophytes and xeromesophytes. Most species are found in biotopes group I: Cultivated agricultural biotopes; least of all species found in biotopes group F: Biotopes dominated by chamephytes and nanophanerophytes. Only 3 species found in biotopes group F: Biotopes dominated by chamephytesand nanophanerophytes. The maps of distribution of 28 invasive species are provided. Most of the species marked dispersed in more than 30 squares.

  11. How Do Grass Species, Season and Ensiling Influence Mycotoxin Content in Forage?

    Directory of Open Access Journals (Sweden)

    Adam Nawrath

    2013-11-01

    Full Text Available Mycotoxins are secondary metabolites produced by fungal species that have harmful effects on mammals. The aim of this study was to assess the content of mycotoxins in fresh-cut material of selected forage grass species both during and at the end of the growing season. We further assessed mycotoxin content in subsequently produced first-cutting silages with respect to the species used in this study: Lolium perenne (cv. Kentaur, Festulolium pabulare (cv. Felina, Festulolium braunii (cv. Perseus, and mixtures of these species with Festuca rubra (cv. Gondolin or Poa pratensis (Slezanka. The mycotoxins deoxynivalenol, zearalenone and T-2 toxin were mainly detected in the fresh-cut grass material, while fumonisin and aflatoxin contents were below the detection limits. July and October were the most risky periods for mycotoxins to occur. During the cold temperatures in November and December, the occurrence of mycotoxins in fresh-cut material declined. Although June was a period with low incidence of mycotoxins in green silage, contents of deoxynivalenol and zearalenone in silages from the first cutting exceeded by several times those determined in their biomass collected directly from the field. Moreover, we observed that use of preservatives or inoculants did not prevent mycotoxin production.

  12. Progress in the remote sensing of C3 and C4 grass species aboveground biomass over time and space

    Science.gov (United States)

    Shoko, Cletah; Mutanga, Onisimo; Dube, Timothy

    2016-10-01

    The remote sensing of grass aboveground biomass (AGB) has gained considerable attention, with substantial research being conducted in the past decades. Of significant importance is their photosynthetic pathways (C3 and C4), which epitomizes a fundamental eco-physiological distinction of grasses functional types. With advances in technology and the availability of remotely sensed data at different spatial, spectral, radiometric and temporal resolutions, coupled with the need for detailed information on vegetation condition, the monitoring of C3 and C4 grasses AGB has received renewed attention, especially in the light of global climate change, biodiversity and, most importantly, food security. This paper provides a detailed survey on the progress of remote sensing application in determining C3 and C4 grass species AGB. Importantly, the importance of species functional type is highlighted in conjunction with the availability and applicability of different remote sensing datasets, with refined resolutions, which provide an opportunity to monitor C3 and C4 grasses AGB. While some progress has been made, this review has revealed the need for further remote sensing studies to model the seasonal (cyclical) variability, as well as long-term AGB changes in C3 and C4 grasses, in the face of climate change and food security. Moreover, the findings of this study have shown the significance of shifting towards the application of advanced statistical models, to further improve C3 and C4 grasses AGB estimation accuracy.

  13. Precious grasses : Alberta Research Council releases new native species for reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, D.

    2006-03-15

    The Alberta Research Council has released 6 new varieties of native plant species suitable for reclamation in Alberta's Parkland region, which is characterized by sandy soils. The Parkland stretches for 37,000 kilometres and is the most densely populated of the province's 6 ecoregions. Because of farming, grazing, oil and gas development and recreation, only 5 per cent of the area remains undisturbed. It was anticipated that the native grasses will help disturbed sites eventually resemble their original state. Varieties included: Aspen Milk Vetch; Centennial Canada Wild Rye; Hillbilly Nodding Brome; Butte Rocky Mountain Fescue; Porter Indian Rice Grass; and Metisko Awned Wheatgrass. The varieties were evaluated for their ability to provide rapid cover and their ability to compete with invading weeds, as well as their ability to allow recruitment of other native species. Multi-environmental testing trials were established to evaluate the species' seed production potential. Seeds were tested for germination in species-specific growth chambers, grown in greenhouses and then taken to an agricultural setting where data on forage density; ground cover; vigour; and biomass were then recorded. The species have also been targeted to ensure that the oil and gas industry has better options for reclaiming disturbed sites. In addition to their ability to combat threats from invasive species, the native plant species have been investigated for their ability to remediate hydrocarbon and salt contaminants and sequester carbon dioxide. Details of Alberta's current reclamation criteria for wellsites and associated facilities were also presented. 4 figs.

  14. Effects of sowing native herbaceous species on the post-fire recovery in a heathland

    Science.gov (United States)

    Fernández-Abascal, I.; Tárrega, R.; Luis-Calabuig, E.; Marcos, E.

    2003-07-01

    Erica australis heathlands in León province (NW Spain) have high resilience to disturbances and their post-fire recovery is very fast. The risk of soil erosion is high in the first few months after fire. The aim of this study is to investigate the effects on post-fire succession of sowing grass ( Agrostis capillaris and Festuca rubra) and legume ( Lotus corniculatus) seeds in a heathland burned by a summer wildfire, and to determine the most suitable native herbaceous species combination for protecting the soil in the first few phases of recovery. Fifteen permanent 4 m 2 plots are established in the burned area; four treatments and a control (unsown) are applied, each with three replicates. Three similar unburned plots are also considered (unburned control). Total cover is significantly higher in the sown plots in relation to the control in the first few months after sowing, but there are no differences after 18 months. Lotus corniculatus appears only in the first year and has no effect on the total cover. F. rubra appears earlier than Agrostis capillaris, but decreases significantly in cover after 18 months. Shrub species have the highest cover in the control plots and the lowest in the Agrostis plots. The correspondence analysis shows that the trend for vegetation in all plots reaches similar species composition by the time of final sampling. The last sampling of sown plots shows greater similarity to the control plots than the sampling of these plots within the first year. The fast initial growth of F. rubra, together with its decrease and subsequent low cover from the second year, make it more preferable than Agrostis capillaris for purposes of soil protection. However, additional research, both species- and site-specific, is necessary, as different responses due to different post-fire conditions and pre-fire species composition can have important implications on community dynamics.

  15. Accumulation of 137Cs and 90Sr from contaminated soil by three grass species inoculated with mycorrhizal fungi

    International Nuclear Information System (INIS)

    The use of plants to accumulate low level radioactive waste from soil, followed by incineration of plant material to concentrate radionuclides may prove to be a viable and economical method of remediating contaminated areas. We tested the influence of arbuscular mycorrhizae on 137Cs and 90Sr uptake by bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) for the effectiveness on three different contaminated soil types. Exposure to 137Cs or 90Sr over the course of the experiment did not affect above ground biomass of the three grasses. The above ground biomass of bahia, johnson and switchgrass plants accumulated from 26.3 to 71.7% of the total amount of the 137Cs and from 23.8 to 88.7% of the total amount of the 90Sr added to the soil after three harvests. In each of the three grass species tested, plants inoculated with Glomus mosseae or Glomus intraradices had greater aboveground plant biomass, higher concentrations of 137Cs or 90Sr in plant tissue, % accumulation of 137Cs or 90Sr from soil and plant bioconcentration ratios at each harvest than those that did not receive mycorrhizal inoculation. Johnson grass had greater aboveground plant biomass, greater accumulation of 137Cs or 90Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137Cs and 90Sr was observed in johnson grass inoculated with G. mosseae. Grasses can grow in wide geographical ranges that include a broad variety of edaphic conditions. The highly efficient removal of these radionuclides by these grass species after inoculation with arbuscular mycorrhizae supports the concept that remediation of radionuclide contaminated soils using mycorrhizal plants may present a viable strategy to remediate and reclaim sites contaminated with radionuclides

  16. Diversity and aggregation patterns of plant species in a grass community

    Directory of Open Access Journals (Sweden)

    Ran Li

    2014-09-01

    Full Text Available Both composition and aggregation patterns of species in a community are the outcome of community self-organizing. In this paper we conducted analysis on species diversity and aggregation patterns of plant species in a grass community, Zhuhai, China. According to the sampling survey, in total of 47 plant species, belonging to 16 families, were found. Compositae had 10 species (21.3%, seconded by Gramineae (9 species, 19.1%, Leguminosae (6 species, 12.8%, Cyperaceae (4 species, 8.5%, and Malvaceae (3 species, 6.4%. The results revealed that the means of aggregation indices Iδ, I and m*/m were 21.71, 15.71 and 19.89 respectively and thus individuals of most of plant species strongly followed aggregative distribution. Iwao analysis indicated that both individuals of all species and clumps of all individuals of all species followed aggregative distribution. Taylor's power law indicated that individuals of all species followed aggregative distribution and aggregation intensity strengthened as the increase of mean density. We held that the strong aggregation intensity of a species has been resulted from the strong adaptation ability to the environment, the strong interspecific competition ability and the earlier establishment of the species. Fitting goodness of the mean, I, Iδ, m*/m with probability distributions demonstrated that the mean (density, I, Iδ, and m*/m over all species followed Weibull distribution rather than normal distribution. Lophatherum gracile, Paederia scandens (Lour. Merr., Eleusine indica, and Alternanthera philoxeroides (Mart. Griseb. were mostly aggregative, and Oxalis sp., Eleocharis plantagineiformis, Vernonia cinerea (L. Less., and Sapium sebiferum (L. Roxb, were mostly uniform in the spatial distribution. Importance values (IV showed that Cynodon dactylon was the most important species, seconded by Desmodium triflorum (L. DC., Cajanus scarabaeoides (L. Benth., Paspalum scrobiculatum L., and Rhynchelytrum repens. Oxalis

  17. Effect of fire and grazing on invasive species in northern mixed grass prairie

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Invasive plants pose a threat to pristine and natural mixed grass prairie so managers seek to control them. On the basis of experience in the tall grass prairie,...

  18. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  19. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

    Science.gov (United States)

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-01-01

    We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot−1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot−1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha−1 yr−1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha−1 yr−1. PMID:26257870

  20. Enhancing cytokinin synthesis by overexpressing ipt alleviated drought inhibition of root growth through activating ROS-scavenging systems in Agrostis stolonifera

    OpenAIRE

    Xu, Yi; Burgess, Patrick; Zhang, Xunzhong; Huang, Bingru

    2016-01-01

    Drought stress limits root growth and inhibits cytokinin (CK) production. Increases in CK production through overexpression of isopentenyltransferase (ipt) alleviate drought damages to promote root growth. The objective of this study was to investigate whether CK-regulated root growth was involved in the alteration of reactive oxygen species (ROS) production and ROS scavenging capacity under drought stress. Wild-type (WT) creeping bentgrass (Agrostis stolonifera L. ‘Penncross’) and a transgen...

  1. N2-fixation and residual N effect of four legume species and four companion grass species

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Søegaard, Karen; Pirhofer-Walzl, Karin;

    2012-01-01

    Inclusion of forage legumes in low-input forage mixtures improves herbage production and soil fertility through addition of nitrogen (N) from N2-fixation. The impact of different grass–legume mixtures on the N contribution of the forage mixture has rarely been investigated under comparable soil...... and climatic conditions. We conducted a field experiment on a sandy soil at two nitrogen levels with seven two-species forage mixtures: alfalfa, bird's-foot trefoil, red clover, or white clover in mixture with perennial ryegrass, and white clover in mixture with meadow fescue, timothy, or hybrid ryegrass. We...

  2. Identity of Schizaphis species (Hemiptera: Aphididae) in the United Kingdom: are they a threat to crops?

    Science.gov (United States)

    Kati, Amalia; Shufran, Kevin A; Taylor, Mark S; Barjadze, Shalva; Eastop, Victor F; Blackman, Roger L; Harrington, Richard

    2013-08-01

    The greenbug, Schizaphis graminum (Rondani), is a major pest of cereals in some parts of the world and is of particular concern because it can be resistant to some insecticides and overcome the resistance of crops. In the UK, it has never been found on crops, but two rather little-known and closely-related species (Schizaphis holci and Schizaphis agrostis) are associated with the wild grasses, Holcus lanatus and Agrostis stolonifera. Since 1987, winged (alate) aphids morphologically resembling the greenbug have been found in increasing numbers in 12.2 m high suction-trap samples of the Rothamsted Insect Survey (RIS); hence, studies were undertaken to establish their identity. Clones (=asexual lineages) established from populations collected from H. lanatus in southern England showed strong preference for Holcus over Agrostis and Hordeum in laboratory tests and produced sexual morphs when transferred to short-day conditions, the males being apterous, as expected for S. holci. Multivariate morphometric comparisons of alatae caught in UK RIS suction traps in 2007 and 2011 with named specimens from museum collections, including S. graminum from many countries, indicated that the suction-trapped alatae were mostly S. agrostis and S. holci. Cytochrome c oxidase subunit I (COI) mtDNA obtained from 62 UK specimens from suction-traps had 95.4-100% sequence identity with US specimens of S. graminum. Two of the UK specimens had identical COI sequence to the US sorghum-adapted form of S. graminum, and these specimens also had 100% identity with a 640 bp fragment of nDNA CytC, indicating that this form of S. graminum may already be present in the UK. Present and future economic implications of these results are discussed. PMID:23458881

  3. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna

    NARCIS (Netherlands)

    Zwerts, J.A.; Prins, H.H.T.; Bomhoff, D.; Verhagen, I.; Swart, J.M.; Boer, de W.F.

    2015-01-01

    South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling) by herbivores on the formation of graz

  4. Energy crop cultivations of reed canary grass - An inferior breeding habitat for the skylark, a characteristic farmland bird species

    Energy Technology Data Exchange (ETDEWEB)

    Vepsaelaeinen, Ville [Finnish Museum of Natural History, P.O. Box 17, University of Helsinki, FI-00014 Helsinki (Finland)

    2010-07-15

    Here, I present the first comparison of the abundance of farmland birds in energy grass fields and in cereal-dominated conventionally cultivated fields (CCFs). I demonstrate that in boreal farmland, skylark (Alauda arvensis) densities were significantly lower in reed canary grass (RCG) (Phalaris arundinacea) fields than in CCFs. I found that during the early breeding season RCG fields and CCFs are equally good habitats, but over the ensuing couple of weeks RCG rapidly grows too tall and dense for field-nesting species. Consequently, RCG is an inferior habitat for skylark for laying replacement clutches (after failure of first nesting) or for a second clutch after one successful nesting. The results imply that if RCG cultivation is to be expanded, the establishment of large monocultures should be avoided in farmland landscapes; otherwise the novel habitat may affect detrimentally the seriously depleted skylark population, and probably also other field-nesting bird species with similar breeding habitats. (author)

  5. LIFE-HISTORY VARIATION IN ECOLOGICALLY CONTRASTING POPULATIONS OF AGROSTIS-STOLONIFERA

    NARCIS (Netherlands)

    Kik, C.; van Andel, Jelte; Joenje, W.

    1990-01-01

    (1) Life-history variation among four ecologically contrasting populations of Agrostis stolonifera was examined using a reciprocal-transplant technique in natural habitats. (2) Survival, growth and flowering were mainly determined environmentally across transplant sites, although population effects

  6. Native Species Establishment on an Oil Drill Pad Site in the Uintah Mountains, Utah: Effects of Introduced Grass Density and Fertilizer

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1989-01-01

    This study examined the effects of introduced grass seeding density and fertilizer on native species establishment on an oil drill pad site in the Uintah Mountains, UT. Differences in first-year seedling density and 3-year standing crop biomass among treatments were evaluated for seeded introduced grasses and native species and for unseeded colonizers. Aerial cover was measured all 3 years and the effects of fertilization on soil NO3-N, available P, and exchangeable K were examined 2 years ...

  7. Harvesting Effects on Species Composition and Distribution of Cover Attributes in Mixed Native Warm-Season Grass Stands

    Directory of Open Access Journals (Sweden)

    Vitalis W. Temu

    2015-05-01

    Full Text Available Managing grasslands for forage and ground-nesting bird habitat requires appropriate defoliation strategies. Subsequent early-summer species composition in mixed stands of native warm-season grasses (Indiangrass (IG, Sorghastrum nutans, big bluestem (BB, Andropogon gerardii and little bluestem (LB, Schizachyrium scoparium responding to harvest intervals (treatments, 30, 40, 60, 90 or 120 d and durations (years in production was assessed. Over three years, phased May harvestings were initiated on sets of randomized plots, ≥90 cm apart, in five replications (blocks to produce one-, two- and three-year-old stands. Two weeks after harvest, the frequencies of occurrence of plant species, litter and bare ground, diagonally across each plot (line intercept, were compared. Harvest intervals did not influence proportions of dominant plant species, occurrence of major plant types or litter, but increased that of bare ground patches. Harvest duration increased the occurrence of herbaceous forbs and bare ground patches, decreased that of tall-growing forbs and litter, but without affecting that of perennial grasses, following a year with more September rainfall. Data suggest that one- or two-year full-season forage harvesting may not compromise subsequent breeding habitat for bobwhites and other ground-nesting birds in similar stands. It may take longer than a year’s rest for similar stands to recover from such changes in species composition.

  8. The weed species composition in a reed canary grass (Phalaris arundinacea L. plantation for energy purposes depending on its age

    Directory of Open Access Journals (Sweden)

    Tomasz R. Sekutowski

    2014-12-01

    Full Text Available The present experiment, carried out in nine production fields of reed canary grass (Phalaris arundinacea grown for energy purposes, evaluated the effect of plantation age on the occurrence and species composition of weeds. The selected plantations were divided into 3 groups that were conventionally called “young” (1–2 years old, “middle-aged” (3–5 years old, and “older” plantations (6–8 years old. Regardless of plantation age, altogether 43 species were found in the experimental fields. Moreover, 6 species were common for all the plantations and were found in them regardless of plantation age. The least species, only 18, were found on the “young” plantations, almost twice more on the “older” ones (30 species, whereas the largest spectrum of species was found in the “middle-aged” plantations (33 species. In the “young” plantations, annual weeds were the most common, with the highest constancy and coverage index found for Chenopodium album, Matricaria maritima ssp. inodora and Echinochloa crus-galli. The greatest variation in species was found in the “middle-aged” plantations. However, only 4 species achieved the highest constancy and coverage index: Matricaria maritima ssp. inodora, Cirsium arvense, Poa trivialis and Taraxacum officinale. Furthermore, perennial weeds were found to be dominant in the “older” plantations. Within this group, Poa trivialis, Taraxacum officinale, Urtica dioica, Plantago maior, and Cirsium arvense had the highest constancy and coverage index.

  9. Optimizing spectral resolutions for the classification of C3 and C4 grass species, using wavelengths of known absorption features

    Science.gov (United States)

    Adjorlolo, Clement; Cho, Moses A.; Mutanga, Onisimo; Ismail, Riyad

    2012-01-01

    Hyperspectral remote-sensing approaches are suitable for detection of the differences in 3-carbon (C3) and four carbon (C4) grass species phenology and composition. However, the application of hyperspectral sensors to vegetation has been hampered by high-dimensionality, spectral redundancy, and multicollinearity problems. In this experiment, resampling of hyperspectral data to wider wavelength intervals, around a few band-centers, sensitive to the biophysical and biochemical properties of C3 or C4 grass species is proposed. The approach accounts for an inherent property of vegetation spectral response: the asymmetrical nature of the inter-band correlations between a waveband and its shorter- and longer-wavelength neighbors. It involves constructing a curve of weighting threshold of correlation (Pearson's r) between a chosen band-center and its neighbors, as a function of wavelength. In addition, data were resampled to some multispectral sensors-ASTER, GeoEye-1, IKONOS, QuickBird, RapidEye, SPOT 5, and WorldView-2 satellites-for comparative purposes, with the proposed method. The resulting datasets were analyzed, using the random forest algorithm. The proposed resampling method achieved improved classification accuracy (κ=0.82), compared to the resampled multispectral datasets (κ=0.78, 0.65, 0.62, 0.59, 0.65, 0.62, 0.76, respectively). Overall, results from this study demonstrated that spectral resolutions for C3 and C4 grasses can be optimized and controlled for high dimensionality and multicollinearity problems, yet yielding high classification accuracies. The findings also provide a sound basis for programming wavebands for future sensors.

  10. Classification of images of wheat, ryegrass and brome grass species at early growth stages using principal component analysis

    Directory of Open Access Journals (Sweden)

    Golzarian Mahmood R

    2011-09-01

    Full Text Available Abstract Wheat is one of the most important crops in Australia, and the identification of young plants is an important step towards developing an automated system for monitoring crop establishment and also for differentiating crop from weeds. In this paper, a framework to differentiate early narrow-leaf wheat from two common weeds from their digital images is developed. A combination of colour, texture and shape features is used. These features are reduced to three descriptors using Principal Component Analysis. The three components provide an effective and significant means for distinguishing the three grasses. Further analysis enables threshold levels to be set for the discrimination of the plant species. The PCA model was evaluated on an independent data set of plants and the results show accuracy of 88% and 85% in the differentiation of ryegrass and brome grass from wheat, respectively. The outcomes of this study can be integrated into new knowledge in developing computer vision systems used in automated weed management.

  11. Characterization of gene expression associated with drought avoidance and tolerance traits in a perennial grass species.

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    Full Text Available To understand molecular mechanisms of perennial grass adaptation to drought stress, genes associated with drought avoidance or tolerance traits were identified and their expression patterns were characterized in C4 hybrid bermudagrass [Cynodon dactylon (L. Pers.×C. transvaalensis Burtt Davy, cv. Tifway] and common bermudagrass (C. dactylon, cv. C299. Plants of drought-tolerant 'Tifway' and drought-sensitive 'C299' were exposed to drought for 5 d (mild stress and 10 d (severe stress by withholding irrigation in a growth chamber. 'Tifway' maintained significantly lower electrolyte leakage and higher relative water content than 'C299' at both 5 and 10 d of drought stress. Four cDNA libraries via suppression subtractive hybridization analysis were constructed and identified 277 drought-responsive genes in the two genotypes at 5 and 10 d of drought stress, which were mainly classified into the functional categories of stress defense, metabolism, osmoregulation, membrane system, signal and regulator, structural protein, protein synthesis and degradation, and energy metabolism. Quantitative-PCR analysis confirmed the expression of 36 drought up-regulated genes that were more highly expressed in drought-tolerant 'Tifway' than drought-sensitive 'C299', including those for drought avoidance traits, such as cuticle wax formation (CER1 and sterol desaturase, for drought tolerance traits, such as dehydration-protective proteins (dehydrins, HVA-22-like protein and oxidative stress defense (superoxide dismutase, dehydroascorbate reductase, 2-Cys peroxiredoxins, and for stress signaling (EREBP-4 like protein and WRKY transcription factor. The results suggest that the expression of genes for stress signaling, cuticle wax accumulation, antioxidant defense, and dehydration-protective protein accumulation could be critically important for warm-season perennial grass adaptation to long-term drought stress.

  12. The effects of seed ingestion by livestock, dung fertilization, trampling, grass competition and fire on seedling establishment of two woody plant species.

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    Julius Tjelele

    Full Text Available The increasing rate of woody plant encroachment in grasslands or savannas remains a challenge to livestock farmers. The causes and control measures of woody plant encroachment are of common interest, especially where it negatively affects the objectives of an agricultural enterprise. The objectives of this study were to determine the effects of gut passage (goats, cattle, dung (nutrients, fire, grass competition and trampling on establishment of A. nilotica and D. cinerea seedlings. Germination trials were subjected to the following treatments: 1 seed passage through the gut of cattle and goats and unpassed/ untreated seeds (i.e. not ingested, 2 dung and control (no dung, 3 grass and control (mowed grass, 4 fire and control (no fire, 5 trampling and control (no trampling. The interaction of animal species, grass and fire had an effect on seedling recruitment (P < 0.0052. Seeds retrieved from goats and planted with no grass and with fire (6.81% ± 0.33 had a significant effect on seedling recruitment than seeds retrieved from goats and planted with grass and no fire (2.98% ± 0.33. Significantly more D. cinerea and A. nilotica seeds germinated following seed ingestion by goats (3.59% ± 0.16 than cattle (1.93% ± 0.09 and control or untreated seeds (1.69% ± 0.11. Less dense grass cover, which resulted in reduced grass competition with tree seedlings for light, space and water, and improved seed scarification due to gut passage were vital for emergence and recruitment of Acacia seedlings. These results will contribute considerably to the understanding of the recruitment phase of woody plant encroachment.

  13. The genus Sitothrips (Thysanoptera: Thripidae) with a new grass-living species from southern Iran.

    Science.gov (United States)

    Minaei, Kambiz; Mound, Laurence

    2014-01-01

    One of the generic characters given by zur Strassen (2003) for species of the genus Sitothrips Priesner (1931) is the presence of 2-segmented maxillary palps. In contrast, a new species of this genus is described below from Iran in which the maxillary palps are clearly 3-segmented (Fig. 5). The genus was erected for arabicus Priesner from Egypt, a species now recorded widely among countries around the Mediterranean, from Morocco to southern Russia. Three further species are listed in Sitothrips: almargeniensis Titschack from Spain and Portugal, lindbergi zur Strassen from the Canary Islands and Morocco, and calcaratus (Savenko) from southern Russia. The identity of the latter species remains in some doubt as, in contrast to the other species, it was described as wingless and lacking ocelli (Savenko 1944), but zur Strassen (2003) provided an illustrated key to the other three species.

  14. Seasonal Changes in Leaf Tissue Rehydration of One Annual and Two Perennial Grass Forage Species Induced by Bioclimate

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    Eirini - Ia KAPSALI

    2015-12-01

    Full Text Available Bioclimate signifies the continuous interplay between plants and climate factors (primarily drought and has a direct impact on the water relations and the duration of the rehydration process in water stressed plants. To explore the association between bioclimate and water physiology of forage species in semi-arid Mediterranean grasslands, we determined the seasonal variation in leaf water potential, turgid weight and relative water content in wild growing Dactylis glomerata L., Bromus inermis Leyss (perennial and Bromus sterilis L. (annual during the growing season. The study was conducted at the farm of the Aristotle University of Thessaloniki. The results of the current study reveal that B. sterilis maintained high levels of water potential most probably by accelerating its biological cycle and decreasing water content because it fails to sustain turgidity. Dactylis glomerata and B. inermis presented even higher water contents than B. sterilis for the same water potential. Dactylis glomerata exhibited substantially higher water potential and content than B. inermis by keeping the rehydration duration stable. The extensive creeping rhizome seems to allow B. inermis to sustain high values of water potential and content possibly ensuring turgidity. Regardless of the grass species the duration of rehydration ranged from 2.5 to 3.5 hours throughout the growing season. Our findings demonstrate that (a D. glomerata and B. inermis are better adapted to Mediterranean semiarid conditions than B. sterilis and (b turgid weight in Mediterranean forage species can safely be determined after a rehydration period of 3.5 hours.

  15. Maximizing biomass production in semi-arid regions: genotypic selection of identified species. [Saltbush and Johnson Grass

    Energy Technology Data Exchange (ETDEWEB)

    Goodin, J.R.; Newton, R.J.

    1983-08-31

    This project identifies genotypes selected from two species of unconventional plants previously identified as having exceptional potential for the production of biomass feedstock in semi-arid regions. The project involved collection of germ plasm from indigenous Atriplex canescens (saltbush) and introduced Sorghum halepense (Johnson grass). In addition, greenhouse and field screening techniques recently aplied to domesticated crop plants are used to identify exceptional biomass productivity based on drought tolerance, salinity tolerance, and seedling vigor. In both of these species, the genetic base is enormous. Saltbush is common to all of western North America, and Johnsongrass had established itself as an important forage and weedy species throughout most of the world. It would appear that artificial selection for desirable genotypes is a feasible process, and this project has demonstrated the possibility of selection from many accessions from the field. Preliminary screening for seedling vigor, drought tolerance, and salt tolerance has produced a few genotypes now ready for field testing. Propagation of these cloned genotypes is underway. 22 references, 2 figures, 1 table.

  16. Abundance and Species Composition of Harpacticoid Copepods from a Sea Grass Patch of South Andaman, India

    Directory of Open Access Journals (Sweden)

    R. Jayabarathi

    2012-11-01

    Full Text Available Abundance and species composition of Harpacticoida (Copepoda inhabiting blades of Thalassia hemprichii and their canopy sediments were examined during the study period. Eleven different meiofaunal taxa were recorded from the study site, among which the blades comprised nine taxa and the canopy sediment constituted all eleven taxa. Harpacticoid Copepods were the dominating meiofaunal component in blades (86% as well as in canopy sediments (57% of T. hemprichii. A total of 47 species belonging to 34 genera distributed within 14 families of harpacticoid copepods were recorded. Harpacticoids on canopy sediments were significantly higher (t-test, p<0.05 compared to the seagrass blades. Canuellina nicobaris was the most abundant species followed by Scottolana longipes and Harpacticus spinulosus in both habitats. Higher diversity (H’ and equitability (J of harpacticoid species were found in blade. Bray Curtis similarity shows that two distinct clusters of species in the habitats.

  17. Gibberellin-Stimulation of Rhizome Elongation and Differential GA-Responsive Proteomic Changes in Two Grass Species

    Science.gov (United States)

    Ma, Xiqing; Huang, Bingru

    2016-01-01

    Rapid and extensive rhizome development is a desirable trait for perennial grass growth and adaptation to environmental stresses. The objective of this study was to determine proteomic changes and associated metabolic pathways of gibberellin (GA) -regulation of rhizome elongation in two perennial grass species differing in rhizome development. Plants of a short-rhizome bunch-type tall fescue (TF; Festuca arundinacea; ‘BR’) and an extensive rhizomatous Kentucky bluegrass (KB; Poa pratensis; ‘Baron’) were treated with 10 μM GA3 in hydroponic culture in growth chambers. The average rhizome length in KB was significantly longer than that in TF regardless of GA3 treatment, and increased significantly with GA3 treatment, to a greater extent than that in TF. Comparative proteomic analysis using two-dimensional electrophoresis and mass spectrometry was performed to further investigate proteins and associated metabolic pathways imparting increased rhizome elongation by GA. A total of 37 and 38 differentially expressed proteins in response to GA3 treatment were identified in TF and KB plants, respectively, which were mainly involved in photosynthesis, energy and amino acid metabolism, protein synthesis, defense and cell development processes. Accelerated rhizome elongation in KB by GA could be mainly associated with the increased abundance of proteins involved in energy metabolism (glyceraldehyde-3-phosphate dehydrogenase, fructose-bisphosphate aldolase, and ATP synthase), amino acid metabolism (S-adenosylmethionine and adenosylhomocysteinase), protein synthesis (HSP90, elongation factor Tu and eukaryotic translation initiation factor 5A), cell-wall development (cell dividion cycle protein, alpha tubulin-2A and actin), and signal transduction (calreticulin). These proteins could be used as candidate proteins for further analysis of molecular mechanisms controlling rhizome growth. PMID:27446135

  18. Modeling the accumulation of As, Cd, Cu, Pb and Zn in grasses (Agrotis sp. and Poa sp. and stinging nettle (Urtica dioica on selected sites taking into account soil physico-chemical properties

    Directory of Open Access Journals (Sweden)

    Boshoff M.C.

    2014-07-01

    Full Text Available The effect of soil properties on the accumulation of metals in two vegetation types was evaluated at 10 sites with a wide variation in soil physicochemical properties pH, organic carbon, clay percentage , total soil metal concentration and exchangeable soil metal content. Accumulation modeling was conducted for grasses (Agrostis sp. and Poa sp. and stinging nettle (Urtica dioica.

  19. Modeling the accumulation of As, Cd, Cu, Pb and Zn in grasses (Agrotis sp. and Poa sp. and stinging nettle (Urtica dioica on selected sites taking into account soil physico-chemical properties

    Directory of Open Access Journals (Sweden)

    Boshoff M. C.

    2013-04-01

    Full Text Available The effect of soil properties on the accumulation of metals in two vegetation types was evaluated at 10 sites with a wide variation in soil physicochemical properties pH, organic carbon, clay percentage , total soil metal concentration and exchangeable soil metal content. Accumulation modeling was conducted for grasses (Agrostis sp. and Poa sp. and stinging nettle (Urtica dioica.

  20. Fusarium dactylidis sp. nov., a novel nivalenol toxin-producing species sister to F. pseudograminearum isolated from orchard grass (Dactylis glomerata) in Oregon and New Zealand.

    Science.gov (United States)

    Aoki, Takayuki; Vaughan, Martha M; McCormick, Susan P; Busman, Mark; Ward, Todd J; Kelly, Amy; O'Donnell, Kerry; Johnston, Peter R; Geiser, David M

    2015-01-01

    The B trichothecene toxin-producing clade (B clade) of Fusarium includes the etiological agents of Fusarium head blight, crown rot of wheat and barley and stem and ear rot of maize. B clade isolates also have been recovered from several wild and cultivated grasses, including Dactylis glomerata (orchard grass or cock's foot), one of the world's most important forage grasses. Two isolates from the latter host are formally described here as F. dactylidis. Phenotypically F. dactylidis most closely resembles F. ussurianum from the Russian Far East. Both species produce symmetrical sporodochial conidia that are similar in size and curved toward both ends. However, conidia of F. ussurianum typically end in a narrow apical beak while the apical cell of F. dactylidis is acute. Fusarium dactylidis produced nivalenol mycotoxin in planta as well as low but detectable amounts of the estrogenic mycotoxin zearalenone in vitro. Results of a pathogenicity test revealed that F. dactylidis induced mild head blight on wheat.

  1. Flavor, glucosinolates, and isothiocyanates of nau (Cook's scurvy grass, Lepidium oleraceum) and other rare New Zealand Lepidium species.

    Science.gov (United States)

    Sansom, Catherine E; Jones, Veronika S; Joyce, Nigel I; Smallfield, Bruce M; Perry, Nigel B; van Klink, John W

    2015-02-18

    The traditionally consumed New Zealand native plant nau, Cook's scurvy grass, Lepidium oleraceum, has a pungent wasabi-like taste, with potential for development as a flavor ingredient. The main glucosinolate in this Brassicaceae was identified by LC-MS and NMR spectroscopy as 3-butenyl glucosinolate (gluconapin, 7-22 mg/g DM in leaves). The leaves were treated to mimic chewing, and the headspace was analyzed by solid-phase microextraction and GC-MS. This showed that 3-butenyl isothiocyanate, with a wasabi-like flavor, was produced by the endogenous myrosinase. Different postharvest treatments were used to create leaf powders as potential flavor products, which were tasted and analyzed for gluconapin and release of 3-butenyl isothiocyanate. A high drying temperature (75 °C) did not give major glucosinolate degradation, but did largely inactivate the myrosinase, resulting in no wasabi-like flavor release. Drying at 45 °C produced more pungent flavor than freeze-drying. Seven other Lepidium species endemic to New Zealand were also analyzed to determine their flavor potential and also whether glucosinolates were taxonomic markers. Six contained mostly gluconapin, but the critically endangered Lepidium banksii had a distinct composition including isopropyl glucosinolate, not detected in the other species. PMID:25625566

  2. The value of small habitat islands for the conservation of genetic variability in a steppe grass species

    Science.gov (United States)

    Wódkiewicz, Maciej; Dembicz, Iwona; Moysiyenko, Ivan I.

    2016-10-01

    The habitat loss and fragmentation due to agricultural land-conversion affected the steppe throughout its range. In Ukraine, 95% of steppe was destroyed in the last two centuries. Remaining populations are confined to few refuges, like nature reserves, loess ravines, and kurgans (small burial mounds), the latter being often subject to destruction by archeological excavations. Stipa capillata L. is a typical grass species of Eurasian steppes and extrazonal dry grasslands, that was previously used as a model species in studies on steppe ecology. The aim of our research was to assess genetic diversity of S. capillata populations within different types of steppe refuges (loess ravines, biosphere reserve, kurgan) and to evaluate the value of the latter group for the preservation of genetic diversity in the study species. We assessed genetic diversity of 266 individuals from 15 populations (nine from kurgans, three from loess ravines and three from Askania-Nova Biosphere Reserve) with eight Universal Rice Primers (URPs). Studied populations showed high intra-population variability (I: 0.262-0.419, PPB: 52.08-82.64%). Populations from kurgans showed higher genetic differentiation (ΦST = 0.247) than those from loess ravines (ΦST = 0.120) and the biosphere reserve (ΦST = 0.142). Although the diversity metrics were to a small extent lower for populations from kurgans than from larger refugia we conclude that all studied populations of the species still preserve high genetic variability and are valuable for protection. To what extent this pattern holds true under continuous fragmentation in the future must be carefully monitored.

  3. Transgenic tobacco plants overexpressing a grass PpEXP1 gene exhibit enhanced tolerance to heat stress.

    Directory of Open Access Journals (Sweden)

    Qian Xu

    Full Text Available Heat stress is a detrimental abiotic stress limiting the growth of many plant species and is associated with various cellular and physiological damages. Expansins are a family of proteins which are known to play roles in regulating cell wall elongation and expansion, as well as other growth and developmental processes. The in vitro roles of expansins regulating plant heat tolerance are not well understood. The objectives of this study were to isolate and clone an expansin gene in a perennial grass species (Poa pratensis and to determine whether over-expression of expansin may improve plant heat tolerance. Tobacco (Nicotiana tabacum was used as the model plant for gene transformation and an expansin gene PpEXP1 from Poa pratensis was cloned. Sequence analysis showed PpEXP1 belonged to α-expansins and was closely related to two expansin genes in other perennial grass species (Festuca pratensis and Agrostis stolonifera as well as Triticum aestivum, Oryza sativa, and Brachypodium distachyon. Transgenic tobacco plants over-expressing PpEXP1 were generated through Agrobacterium-mediated transformation. Under heat stress (42°C in growth chambers, transgenic tobacco plants over-expressing the PpEXP1 gene exhibited a less structural damage to cells, lower electrolyte leakage, lower levels of membrane lipid peroxidation, and lower content of hydrogen peroxide, as well as higher chlorophyll content, net photosynthetic rate, relative water content, activity of antioxidant enzyme, and seed germination rates, compared to the wild-type plants. These results demonstrated the positive roles of PpEXP1 in enhancing plant tolerance to heat stress and the possibility of using expansins for genetic modification of cool-season perennial grasses in the development of heat-tolerant germplasm and cultivars.

  4. Grass Lignocellulose

    Science.gov (United States)

    Akin, Danny E.

    Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.

  5. Analysis of lignin-polysaccharide complexes formed during grass lignin degradation by cultures of Pleurotus species

    OpenAIRE

    Gutiérrez Suárez, Ana; Bocchini, P.; Galletti, Guido C.; Martínez, Ángel T.

    1996-01-01

    A brown material, precipitable with ethanol, was formed during wheat straw and lignin degradation by liquid cultures of different species of Pleurotus. Fourier transform infrared spectroscopy and cross-polarization and magic-angle-spinning (sup13)C nuclear magnetic resonance spectroscopy showed that most of the precipitable material was formed from exopolysaccharide secreted by the fungus but it also contained an aromatic fraction. The results of acid hydrolysis, methylation analysis, and Smi...

  6. Contrasting nurse plants and nurse rocks: The spatial distribution of seedlings of two sub-Antarctic species

    Science.gov (United States)

    Haussmann, N. S.; McGeoch, M. A.; Boelhouwers, J. C.

    2010-05-01

    Positive plant interactions, such as those associated with nurse plants, have been suggested to dominate over negative interactions in environments with high abiotic stress. Here we demonstrate that the sub-Antarctic cushion plant species, Azorella selago (Apiaceae), positively affects the distribution of both its own seedlings and those of the perennial grass, Agrostis magellanica (Poaceae). As a result of the light weight and small size of seeds of both species, coupled with strong winds experienced in the study area, we consider it unlikely that these patterns are the result of very localized seed dispersal from the study cushions themselves. Instead, we suggest that both cushions and rocks act as seed traps, trapping seeds dispersed by wind, runoff and/or downslope sediment transport through frost creep. In addition, increased A. selago seedling numbers around cushions, but not around rocks, suggest that cushions provide a biological nurse effect, such as improving soil nutrient status or providing mychorrizae, to seedlings of their own kind.

  7. Effect of species of cool-season annual grass interseeded into Bermudagrass sod on the performance of growing calves.

    Science.gov (United States)

    Beck, P A; Stewart, C B; Phillips, J M; Watkins, K B; Gunter, S A

    2007-02-01

    Two experiments were conducted to evaluate the effect of species of cool-season annual grass on the growth of stocker cattle over 3 yr. In Exp. 1, the small grains (SG) oat (O), rye (R), and wheat (W), or combinations of SG and annual ryegrass (RG), were interseeded into Bermudagrass sod in a completely randomized design with a 3 x 2 factorial arrangement of treatments. In Exp. 2, RG was planted alone or with O, R, triticale (T), or W in a completely randomized design. Pastures were planted in late October of each year, and seeding rates were 134.4 and 22.4 kg/ha for SG and RG, respectively. In Exp. 1, grazing was initiated on December 18. In Exp. 2, grazing was initiated on December 23 for SG pastures and January 21 or February 16 for RG pastures in yr 1 and on December 8 for all pastures in yr 2. Grazing was managed using the put-and-take method, in which additional calves were added as needed to maintain equal grazing pressure among pastures. In Exp. 1, no interactions (P > or = 0.28) were detected, so the main effects of SG species and RG addition are discussed. From December 18 to March 12, there were no differences in ADG (P > or = 0.17), whereas during the spring (from March 12 to May 7), addition of RG increased (P = 0.05) ADG. Using RG increased (P or = 0.44) in ADG, BW gain/hectare, or grazing-days/hectare. In conclusion, the choice of cool-season annual to establish is highly weather-dependent, but R and W are generally superior to other small grains, and RG is a necessary complement to SG when interseeding cool-season annuals into Bermudagrass sod.

  8. Comparative Proteomic Analysis of the Stolon Cold Stress Response between the C4 Perennial Grass Species Zoysia japonica and Zoysia metrella

    OpenAIRE

    Xuan, Jiping; Song, Yufeng; Zhang, Hongxiao; Liu, Jianxiu; Guo, Zhongren; Hua, Yuelou

    2013-01-01

    Zoysiagrass, the most cold-tolerant grass among the warm-season turfgrasses, is often used as a model species for isolating cellular components related to cold stress. To understand the proteomic responses to cold stress in zoysiagrass stolons, we extracted stolon proteins from Zoysia japonica , cv. Meyer (cold-tolerant) and Z . metrella , cv. Diamond (cold-sensitive), which were grown with or without cold treatment. Approximately 700 proteins were resolved on 2-DE gels, and 70 protein spots ...

  9. Identification of some Malaysian grasses

    NARCIS (Netherlands)

    Henrard, J.Th.

    1935-01-01

    When BUSE gave an enumeration of the grasses collected by JUNGHUHN in Java and Sumatra, he mentioned under Paspalum a species, described by RETZIUS in the year 1781 as Paspalum hirsutum. BUSE identified a grass from Sumatra as being the species of RETZIUS, on account of the description, having certa

  10. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna.

    Directory of Open Access Journals (Sweden)

    J A Zwerts

    Full Text Available South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon and a species that is frequently found outside grazing lawns (Hyparrhenia hirta, and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns.

  11. Comparative feedstock analysis in Setaria viridis L. as a model for C4 bioenergy grasses and Panicoid crop species

    Directory of Open Access Journals (Sweden)

    Carloalberto ePetti

    2013-06-01

    Full Text Available Second generation feedstocks for bioethanol will likely include a sizable proportion of perennial C4 grasses, principally in the Panicoideae clade. The Panicoideae contain agronomically important annual grasses including Zea mays L. (maize, Sorghum bicolor (L. Moench (sorghum, and Saccharum officinarum L. (sugar cane as well as promising second generation perennial feedstocks including Miscanthus x giganteus and Panicum virgatum L. (switchgrass. The underlying complexity of these polyploid grass genomes is a major limitation for their direct manipulation and thus driving a need for rapidly cycling comparative model. Setaria viridis (green millet is a rapid cycling C4 Panicoid grass with a relatively small and sequenced diploid genome and abundant seed production. Stable, transient and protoplast transformation technologies have also been developed for S. viridis making it a potentially excellent model for other C4 bioenergy grasses. Here, the lignocellulosic feedstock composition, cellulose biosynthesis inhibitor (CBI response and saccharification dynamics of S. viridis are compared with the annual s00orghum and maize and the perennial switchgrass bioenergy crops as a baseline study into the applicability for translational research. A genome-wide systematic investigation of the cellulose synthase-A (CesA genes was performed identifying eight candidate sequences. Two-developmental stages; a metabolically active young tissue and b metabolically plateaued (mature material are examined to compare biomass performance metrics.

  12. THE EFFECT OF GROWTH REGULATOR ON STRUCTURAL AND NON-STRUCTURAL CARBOHYDRATES AND LIGNIN CONTENT IN SELECTED GRASS SPECIES AND CULTIVARS

    Directory of Open Access Journals (Sweden)

    Grażyna Anna Ciepiela

    2015-06-01

    Full Text Available The research was undertaken to determine the effect of the biostimulant Kelpak SL, derived from brown seaweed species Ecklonia maxima (kelp, on structural and non-structural carbohydrates, as well as lignin content in orchard grass and Braun’s festulolium. The experiment was a split-plot arrangement with three replicates. It was set up at the experimental facility of the University of Natural Sciences and Humanities, Siedlce, in late April 2009. The following factors were examined: an application of the plant growth regulator Kelpak SL applied at the rate of 2 dm3· ha-1 vs an untreated control (0 dm3· ha-1, pure sown grass species and cultivars grown in monoculture: Dactylis glomerata, cv. Amila and Tukan, as well as Festulolium braunii cv. Felopa and Agula. This study revealed that an application of Kelpak significantly reduced cellulose, hemicellulose and lignin contents of the grasses but significantly increased non-structural carbohydrates, regardless of the remaining factors. Non-structural carbohydrates were the highest in Kelpak-treated Festulolium braunii (on average, 232.7 g · kg-1.

  13. Establishment of non-native plant species after wildfires: Effects of fuel treatments, abiotic and biotic factors, and post-fire grass seeding treatments

    Science.gov (United States)

    Hunter, M.E.; Omi, P.N.; Martinson, E.J.; Chong, G.W.

    2006-01-01

    Establishment and spread of non-native species following wildfires can pose threats to long-term native plant recovery. Factors such as disturbance severity, resource availability, and propagule pressure may influence where non-native species establish in burned areas. In addition, pre- and post-fire management activities may influence the likelihood of non-native species establishment. In the present study we examine the establishment of non-native species after wildfires in relation to native species richness, fire severity, dominant native plant cover, resource availability, and pre- and post-fire management actions (fuel treatments and post-fire rehabilitation treatments). We used an information-theoretic approach to compare alternative hypotheses. We analysed post-fire effects at multiple scales at three wildfires in Colorado and New Mexico. For large and small spatial scales at all fires, fire severity was the most consistent predictor of non-native species cover. Non-native species cover was also correlated with high native species richness, low native dominant species cover, and high seeded grass cover. There was a positive, but non-significant, association of non-native species with fuel-treated areas at one wildfire. While there may be some potential for fuels treatments to promote non-native species establishment, wildfire and post-fire seeding treatments seem to have a larger impact on non-native species. ?? IAWF 2006.

  14. Optimization of delignification of two Pennisetum grass species by NaOH pretreatment using Taguchi and ANN statistical approach.

    Science.gov (United States)

    Mohaptra, Sonali; Dash, Preeti Krishna; Behera, Sudhanshu Shekar; Thatoi, Hrudayanath

    2016-01-01

    In the bioconversion of lignocelluloses for bioethanol, pretreatment seems to be the most important step which improves the elimination of the lignin and hemicelluloses content, exposing cellulose to further hydrolysis. The present study discusses the application of dynamic statistical techniques like the Taguchi method and artificial neural network (ANN) in the optimization of pretreatment of lignocellulosic biomasses such as Hybrid Napier grass (HNG) (Pennisetum purpureum) and Denanath grass (DG) (Pennisetum pedicellatum), using alkali sodium hydroxide. This study analysed and determined a parameter combination with a low number of experiments by using the Taguchi method in which both the substrates can be efficiently pretreated. The optimized parameters obtained from the L16 orthogonal array are soaking time (18 and 26 h), temperature (60°C and 55°C), and alkali concentration (1%) for HNG and DG, respectively. High performance liquid chromatography analysis of the optimized pretreated grass varieties confirmed the presence of glucan (47.94% and 46.50%), xylan (9.35% and 7.95%), arabinan (2.15% and 2.2%), and galactan/mannan (1.44% and 1.52%) for HNG and DG, respectively. Physicochemical characterization studies of native and alkali-pretreated grasses were carried out by scanning electron microscopy and Fourier transformation Infrared spectroscopy which revealed some morphological differences between the native and optimized pretreated samples. Model validation by ANN showed a good agreement between experimental results and the predicted responses. PMID:26584152

  15. The effect of ensiling and haymaking on the concentrations of steroidal saponin in two Brachiaria grass species

    Science.gov (United States)

    Brachiaria (signalgrass) is now the most widely used tropical grass genus in Central and South America. However, Brachiaria spp. can cause hepatogenous photosensitization in livestock. Steroidal saponins, specifically protodioscin, present in Brachiaria spp. may be responsible for liver injury and s...

  16. Profiles of Nonstructural Carbohydrates, as a Function of Species and Extraction Method, in Four Cool-Season Forage Grasses

    Science.gov (United States)

    Nonstructural carbohydrates (NSC) of forage grasses, particularly long-chain fructans, have been proposed as the causal agent of equine laminitis. In order to evaluate the correlation between NSC and laminitis, NSC must be quantified in the forages being fed to and grazed by horses. The goal of th...

  17. Forage yield and nutritive value of Elephant grass, Italian ryegrass and spontaneous growing species mixed with forage peanut or red clover

    Directory of Open Access Journals (Sweden)

    Michelle Schalemberg Diehl

    2014-10-01

    Full Text Available The objective of this research was to evaluate of three grazing systems (GS with elephant grass (EG, Italian ryegrass (IR + spontaneous growing species (SGS; EG + IR + SGS + forage peanut (FP; and EG + IR + SGS + red clover (RC, during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP, neutral detergent fiber (NDF, in situ dry matter digestibility (ISDMD, in situ organic matter digestibility (ISOMD of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.

  18. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    International Nuclear Information System (INIS)

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 μg g-1. Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass

  19. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Deram, Annabelle [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France)]. E-mail: aderam@ilis.univ-lille2.fr; Denayer, Franck-Olivier [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France); Petit, Daniel [Laboratoire de Genetique et Evolution des Populations Vegetales, UPRESA-CNRS 8016, Bat SN2, Universite des Sciences et Techniques de Lille, 59655 Villeneuve d' Ascq, F59655 France (France); Van Haluwyn, Chantal [Faculte des Sciences Pharmaceutiques et Biologiques, Departement de Botanique, Universite Droit et Sante de Lille, EA 2690, B.P. 83, 59006 Lille Cedex (France)

    2006-03-15

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 {mu}g g{sup -1}. Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass.

  20. EVALUATING THE ROLE OF HABITAT QUALITY ON ESTABLISHMENT OF GM AGROSTIS STOLONIFERA IN NON-AGRONOMIC ENVIRONMENTS

    Science.gov (United States)

    The initial flowering of experimental fields of the GM wind-pollinated plant Agrostis stolonifera L. that expressed an engineered gene (CP4 EPSPS) for resistance to glyphosate herbicide in central Oregon in 2003 afforded researchers a unique opportunity to track gene flow ...

  1. Spectral resampling based on user-defined inter-band correlation filter: C3 and C4 grass species classification

    Science.gov (United States)

    Adjorlolo, Clement; Mutanga, Onisimo; Cho, Moses A.; Ismail, Riyad

    2013-04-01

    In this paper, a user-defined inter-band correlation filter function was used to resample hyperspectral data and thereby mitigate the problem of multicollinearity in classification analysis. The proposed resampling technique convolves the spectral dependence information between a chosen band-centre and its shorter and longer wavelength neighbours. Weighting threshold of inter-band correlation (WTC, Pearson's r) was calculated, whereby r = 1 at the band-centre. Various WTC (r = 0.99, r = 0.95 and r = 0.90) were assessed, and bands with coefficients beyond a chosen threshold were assigned r = 0. The resultant data were used in the random forest analysis to classify in situ C3 and C4 grass canopy reflectance. The respective WTC datasets yielded improved classification accuracies (kappa = 0.82, 0.79 and 0.76) with less correlated wavebands when compared to resampled Hyperion bands (kappa = 0.76). Overall, the results obtained from this study suggested that resampling of hyperspectral data should account for the spectral dependence information to improve overall classification accuracy as well as reducing the problem of multicollinearity.

  2. Four new species of the grass feeding leafhopper genus Nicolaus Lindberg (Hemiptera: Cicadellidae: Deltocephalinae) from the Indian subcontinent.

    Science.gov (United States)

    Viraktamath, C A; Webb, M D

    2014-01-01

    The leafhopper genus Nicolaus Lindberg is recorded from India and Pakistan for the first time. Four new species, N. abuensis sp. nov., N. bidentatus sp. nov., N. cornutus sp. nov. and N. serratus sp. nov. are described and illustrated. N. bihamatus Xing & Li, earlier known from China is recorded from India and Pakistan. A key to the species of Nicolaus from the study area is provided.

  3. The importance of rare species: a trait-based assessment of rare species contributions to functional diversity and possible ecosystem function in tall-grass prairies

    OpenAIRE

    Jain, Meha; Flynn, Dan FB; Prager, Case M; Hart, Georgia M; DeVan, Caroline M; Ahrestani, Farshid S; Palmer, Matthew I; Bunker, Daniel E; Knops, Johannes MH; Jouseau, Claire F; Naeem, Shahid

    2013-01-01

    The majority of species in ecosystems are rare, but the ecosystem consequences of losing rare species are poorly known. To understand how rare species may influence ecosystem functioning, this study quantifies the contribution of species based on their relative level of rarity to community functional diversity using a trait-based approach. Given that rarity can be defined in several different ways, we use four different definitions of rarity: abundance (mean and maximum), geographic range, an...

  4. Comparative proteomic analysis of the stolon cold stress response between the C4 perennial grass species Zoysia japonica and Zoysia metrella.

    Directory of Open Access Journals (Sweden)

    Jiping Xuan

    Full Text Available Zoysiagrass, the most cold-tolerant grass among the warm-season turfgrasses, is often used as a model species for isolating cellular components related to cold stress. To understand the proteomic responses to cold stress in zoysiagrass stolons, we extracted stolon proteins from Zoysiajaponica, cv. Meyer (cold-tolerant and Z. metrella, cv. Diamond (cold-sensitive, which were grown with or without cold treatment. Approximately 700 proteins were resolved on 2-DE gels, and 70 protein spots were differentially accumulated. We further observed that 45 of the identified proteins participate in 10 metabolic pathways and cellular processes. A significantly greater number of proteins accumulated in the Meyer than in the Diamond and 15 increased proteins were detected only in the Meyer cultivar under cold stress. Furthermore, we propose a cold stress-responsive protein network composed of several different functional components that exhibits a balance between reactive oxygen species (ROS production and scavenging, accelerated protein biosynthesis and proteolysis, reduced protein folding, enhanced photosynthesis, abundant energy supply and enhanced biosynthesis of carbohydrates and nucleotides. Generally, the cold-tolerant Meyer cultivar showed a greater ROS scavenging ability, more abundant energy supply and increased photosynthesis and protein synthesis than did the cold-sensitive Diamond cultivar, which may partly explain why Meyer is more cold tolerant.

  5. Quantitative Analysis of Plant Consumption and Preference by Oedaleus asiaticus (Acrididae: Oedipodinae) in Changed Plant Communities Consisting of Three Grass Species.

    Science.gov (United States)

    Huang, X; McNeill, M; Zhang, Z

    2016-02-01

    We used Oedaleus asiaticus Bey-Bienko (Acrididae: Oedipodinae) as a model species to examine how plant community composition influenced grasshopper population densities and feeding habits. Our results show that in the Xinli Gol Grassland ecosystem, both plant community composition and grasshopper density vary considerably over fairly small distances, and that O. asiaticus density was directly related to the proportional abundance of specific plant species. A 60-d field-cage study showed that O. asiaticus food preference and consumption differed when the ratios of three dominant grass species (Leymus chinensis (Trin.) Tzvel, Stipa krylovii Roshev, and Cleistogenes squarrosa (Trin.) Keng) differed. The consumption of both S. krylovii and C. squarrosa increased with a corresponding increase in their respective biomass availability. Although O. asiaticus preferred S. krylovii and ate only small amounts of L. chinensis, a specific amount of L. chinensis was always consumed. Feeding of these three plant species could be divided into three levels based on diet selectivity index (SI), with O. asiaticus showing a strong preference for S. krylovii (SI > 1), over that for C. squarrosa (0.5 consumption and preference by O. asiaticus was in decreasing order S. krylovii>C. squarrosa>L. chinensis. This study shows that small-scale changes in plant community composition can have large affects on grasshopper diets and populations. As such, this study is useful for developing guidelines for the monitoring of O. asiaticus impacts against the background of vegetation succession and changing plant communities in response to grazing or human activities. PMID:26577863

  6. The effect of exotic grass Urochloa decumbens (Stapf R.D.Webster (Poaceae in the reduction of species richness and change of floristic composition of natural regeneration in the Floresta Nacional de Carajás, Brazil

    Directory of Open Access Journals (Sweden)

    LEANDRO V. FERREIRA

    2016-01-01

    Full Text Available ABSTRACT The introduction of exotic species is considered as one of the major causes of biodiversity loss. The National Forest of Carajás is one of the largest mineral provinces in the world. Mining activities caused changes of the natural habitats, leaving degraded areas after the mineral exploitation. One of the mining areas within FLONA Carajás was used for the extraction of gold. In the process of exploitation, a huge depression was formed by the removal of soil which was mounded up nearby. To prevent soil erosion of these mounds, an exotic grass, Urochloa decumbens (Stapf R.D.Webster (Poaceae was planted. The objective of this study was to compare the impact of this non-native grass on species richness and species composition of the natural regeneration in the degraded areas. Four areas were compared, two with and two without presence of U. decumbens. In each area, twenty four 1m²/plots were established. Species richness of the regeneration areas and population sizes were significantly lower in the plots where the exotic grass was present. Our study shows that U. decumbens had a negative effect on species richness and population density, and its presence changed the species composition and distribution of life forms of the natural regeneration.

  7. The effect of exotic grass Urochloa decumbens (Stapf) R.D.Webster (Poaceae) in the reduction of species richness and change of floristic composition of natural regeneration in the Floresta Nacional de Carajás, Brazil.

    Science.gov (United States)

    Ferreira, Leandro V; Parolin, Pia; Matos, Darley C L; Cunha, Denise A; Chaves, Priscilla P; Neckel, Selvino O

    2016-01-01

    The introduction of exotic species is considered as one of the major causes of biodiversity loss. The National Forest of Carajás is one of the largest mineral provinces in the world. Mining activities caused changes of the natural habitats, leaving degraded areas after the mineral exploitation. One of the mining areas within FLONA Carajás was used for the extraction of gold. In the process of exploitation, a huge depression was formed by the removal of soil which was mounded up nearby. To prevent soil erosion of these mounds, an exotic grass, Urochloa decumbens (Stapf) R.D.Webster (Poaceae) was planted. The objective of this study was to compare the impact of this non-native grass on species richness and species composition of the natural regeneration in the degraded areas. Four areas were compared, two with and two without presence of U. decumbens. In each area, twenty four 1m²/plots were established. Species richness of the regeneration areas and population sizes were significantly lower in the plots where the exotic grass was present. Our study shows that U. decumbens had a negative effect on species richness and population density, and its presence changed the species composition and distribution of life forms of the natural regeneration. PMID:27142539

  8. Expression of a novel antimicrobial peptide Penaeidin4-1 in creeping bentgrass (Agrostis stolonifera L. enhances plant fungal disease resistance.

    Directory of Open Access Journals (Sweden)

    Man Zhou

    Full Text Available BACKGROUND: Turfgrass species are agriculturally and economically important perennial crops. Turfgrass species are highly susceptible to a wide range of fungal pathogens. Dollar spot and brown patch, two important diseases caused by fungal pathogens Sclerotinia homoecarpa and Rhizoctonia solani, respectively, are among the most severe turfgrass diseases. Currently, turf fungal disease control mainly relies on fungicide treatments, which raises many concerns for human health and the environment. Antimicrobial peptides found in various organisms play an important role in innate immune response. METHODOLOGY/PRINCIPAL FINDINGS: The antimicrobial peptide - Penaeidin4-1 (Pen4-1 from the shrimp, Litopenaeus setiferus has been reported to possess in vitro antifungal and antibacterial activities against various economically important fungal and bacterial pathogens. In this study, we have studied the feasibility of using this novel peptide for engineering enhanced disease resistance into creeping bentgrass plants (Agrostis stolonifera L., cv. Penn A-4. Two DNA constructs were prepared containing either the coding sequence of a single peptide, Pen4-1 or the DNA sequence coding for the transit signal peptide of the secreted tobacco AP24 protein translationally fused to the Pen4-1 coding sequence. A maize ubiquitin promoter was used in both constructs to drive gene expression. Transgenic turfgrass plants containing different DNA constructs were generated by Agrobacterium-mediated transformation and analyzed for transgene insertion and expression. In replicated in vitro and in vivo experiments under controlled environments, transgenic plants exhibited significantly enhanced resistance to dollar spot and brown patch, the two major fungal diseases in turfgrass. The targeting of Pen4-1 to endoplasmic reticulum by the transit peptide of AP24 protein did not significantly impact disease resistance in transgenic plants. CONCLUSION/SIGNIFICANCE: Our results

  9. Species-specific adaptations explain resilience of herbaceous understorey to increased precipitation variability in a Mediterranean oak woodland.

    Science.gov (United States)

    Jongen, Marjan; Hellmann, Christine; Unger, Stephan

    2015-10-01

    To date, the implications of the predicted greater intra-annual variability and extremes in precipitation on ecosystem functioning have received little attention. This study presents results on leaf-level physiological responses of five species covering the functional groups grasses, forbs, and legumes in the understorey of a Mediterranean oak woodland, with increasing precipitation variability, without altering total annual precipitation inputs. Although extending the dry period between precipitation events from 3 to 6 weeks led to increased soil moisture deficit, overall treatment effects on photosynthetic performance were not observed in the studied species. This resilience to prolonged water stress was explained by different physiological and morphological strategies to withstand periods below the wilting point, that is, isohydric behavior in Agrostis, Rumex, and Tuberaria, leaf succulence in Rumex, and taproots in Tolpis. In addition, quick recovery upon irrigation events and species-specific adaptations of water-use efficiency with longer dry periods and larger precipitation events contributed to the observed resilience in productivity of the annual plant community. Although none of the species exhibited a change in cover with increasing precipitation variability, leaf physiology of the legume Ornithopus exhibited signs of sensitivity to moisture deficit, which may have implications for the agricultural practice of seeding legume-rich mixtures in Mediterranean grassland-type systems. This highlights the need for long-term precipitation manipulation experiments to capture possible directional changes in species composition and seed bank development, which can subsequently affect ecosystem state and functioning. PMID:26664676

  10. Development of innovative technique that may be used as models for the increase of biomass production with grasses and other species

    Science.gov (United States)

    Burton, G. W.; Hanna, W. W.

    1981-09-01

    Techniques for biomass increase are discussed: irradiation breeding of sterile triploid turf bermuda grasses; irradiation breeding of sterile Coastcross-1, a forage grass hybrid to increase winter hardiness; heterosis resulting from crossing specific irradiation induced mutants with their normal inbred parent; use of mitomycin and streptomycin to create cytoplasmic male sterile mutants in pearl millet; biomass of napiergrass; evaluation of mutagen induced lignin mutants to maximize metabolizable energy in sorghum; interspecific crosses in Pennisetum; production of homozygous translocation tester stocks; use of radiation to induce and transfer reproductive behavior in plants; and genetics of radiation induced mutations.

  11. Resistance of closely-mown fine fescue and bentgrass species to snow mold pathogens

    Science.gov (United States)

    Creeping bentgrass (Agrostis stolonifera) is the primary species used on golf courses in temperate regions but requires prophylactic fungicide treatment to prevent snow mold diseases. We hypothesized that fine fescues (Festuca spp.) and colonial bentgrass (A. capillaris) have superior resistance to...

  12. Tolérance au Cu chez Agrostis capillaris L. : du phénotype vers les mécanismes moléculaires

    OpenAIRE

    Hego, Elena

    2014-01-01

    Cu-tolerant (metallicolous: M) and sensitive (non-metallicolous: NM) populations of Agrostis capillaris L. were exposed to increasing Cu concentrations (1-50 μM) to investigate Cu tolerance by a pluridisciplinary approach. Phenotypic parameters (biomass production, shoot length, and visual symptoms) indicated a higher growth and a better fitness of M plants over 10 μM Cu. Plant Cu concentrations indicated root Cu retention (‘excluder’ phenotype) and a reduced root-to-shoot translocation with ...

  13. Subtropical grass pollen allergens are important for allergic respiratory diseases in subtropical regions

    Directory of Open Access Journals (Sweden)

    Davies Janet

    2012-03-01

    Full Text Available Abstract Background Grass pollen allergens are a major cause of allergic respiratory disease but traditionally prescribing practice for grass pollen allergen-specific immunotherapy has favoured pollen extracts of temperate grasses. Here we aim to compare allergy to subtropical and temperate grass pollens in patients with allergic rhinitis from a subtropical region of Australia. Methods Sensitization to pollen extracts of the subtropical Bahia grass (Paspalum notatum, Johnson grass (Sorghum halepense and Bermuda grass (Cynodon dactylon as well as the temperate Ryegrass (Lolium perenne were measured by skin prick in 233 subjects from Brisbane. Grass pollen-specific IgE reactivity was tested by ELISA and cross-inhibition ELISA. Results Patients with grass pollen allergy from a subtropical region showed higher skin prick diameters with subtropical Bahia grass and Bermuda grass pollens than with Johnson grass and Ryegrass pollens. IgE reactivity was higher with pollen of Bahia grass than Bermuda grass, Johnson grass and Ryegrass. Patients showed asymmetric cross-inhibition of IgE reactivity with subtropical grass pollens that was not blocked by temperate grass pollen allergens indicating the presence of species-specific IgE binding sites of subtropical grass pollen allergens that are not represented in temperate grass pollens. Conclusions Subtropical grass pollens are more important allergen sources than temperate grass pollens for patients from a subtropical region. Targeting allergen-specific immunotherapy to subtropical grass pollen allergens in patients with allergic rhinitis in subtropical regions could improve treatment efficacy thereby reducing the burden of allergic rhinitis and asthma.

  14. Pests in Ornamental Grasses

    Science.gov (United States)

    Ornamental perennial grasses are becoming increasingly popular in the landscape due to their beauty and ease of care. Although few pest problems are encountered in ornamental grasses, they are not immune to insects and disease. Two lined spittlebugs (Prosapia bicincta) can cause damage to ornament...

  15. Pb pollution in soils from a trap shooting range and the phytoremediation ability of Agrostis capillaris L.

    Science.gov (United States)

    Rodríguez-Seijo, Andrés; Lago-Vila, Manoel; Andrade, María Luisa; Vega, Flora A

    2016-01-01

    Pb pollution caused by shooting sport activities is a serious environmental problem that has increased considerably in recent decades. The aims of this study were firstly to analyze Pb pollution in soils from a trap shooting range abandoned in 1999, secondly to study the effectiveness of different extractants [CaCl2, DTPA, NH4OAc, low molecular weight organic acids (LMWOA), and bidistilled water (BDW)] in order to determine Pb bioavailability in these soils, and finally to evaluate the phytoremediation ability of spontaneous vegetation (Agrostis capillaris L.). To this end, 13 soils from an old trap shooting range (Galicia, NW Spain) were studied. It was found that Pb levels in the soils were higher than 100 mg kg(-1), exceeding the generic reference levels, and three of these samples even exceeded the USEPA threshold level (400 mg kg(-1)). In general, the reagent that best represents Pb bioavailability and has the greatest extraction efficiency was CaCl2, followed by DTPA, NH4OAc, LMWOA, and BDW. A. capillaris Pb contents ranged between 9.82 and 1107.42 mg kg(-1) (root) and between 6.43 and 135.23 mg kg(-1) (shoot). Pb accumulation in roots, as well as the presence of secondary mineral phases of metallic Pb in the adjacent soil, showed the phytostabilization properties of A. capillaris.

  16. Agromorphological characterization and dollar spot fungus susceptibility in accessions of common bent (Agrostis capillaris L.) collected in northern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, J. A.; Novo-Uzal, E.; Pomar, F.; Burghrara, S. S.; Afif, E.

    2010-07-01

    Fourteen Agrostis capillaris accessions collected in northern Spain were characterized in a trial with a low fertilization regime, carried out in two successive years (2004 and 2005). The commercial cultivar Golfin was included in the study as a control. All accessions and the commercial cultivar were evaluated for 11 agromorphological characteristics and susceptibility to dollar spot disease, caused by Sclerotinia homoeocarpa F.T. Bennet. The data obtained were reduced to five principal components that cumulatively explained 85.4% of the total variance. Cluster analysis was useful in identifying four groups of accessions that described 50% of the phenotypic variation among accessions. Cluster 1 consisted of four accessions with the highest resistance to dollar spot, dark green colour, late heading date and high autumn turf quality. Cluster 2 included the two earliest heading accessions, dark green colour, intermediate tolerance to dollar spot and low autumn turf quality. Cluster 3 comprised six accessions with the latest heading date, dark green colour and low tolerance to dollar spot. Cluster 4 consisted of two accessions and the Golfin cultivar, with lightest green colour, low autumn turf quality and the poorest tolerance to dollar spot. The results of this study suggest the potential value of some of these common bent accessions collected in northern Spain for turf and forage improvement. (Author) 40 refs.

  17. Molecular control of grass inflorescence development.

    Science.gov (United States)

    Zhang, Dabing; Yuan, Zheng

    2014-01-01

    The grass family is one of the largest families in angiosperms and has evolved a characteristic inflorescence morphology, with complex branches and specialized spikelets. The origin and development of the highly divergent inflorescence architecture in grasses have recently received much attention. Increasing evidence has revealed that numerous factors, such as transcription factors and plant hormones, play key roles in determining reproductive meristem fate and inflorescence patterning in grasses. Moreover, some molecular switches that have been implicated in specifying inflorescence shapes contribute significantly to grain yields in cereals. Here, we review key genetic and molecular switches recently identified from two model grass species, rice (Oryza sativa) and maize (Zea mays), that regulate inflorescence morphology specification, including meristem identity, meristem size and maintenance, initiation and outgrowth of axillary meristems, and organogenesis. Furthermore, we summarize emerging networks of genes and pathways in grass inflorescence morphogenesis and emphasize their evolutionary divergence in comparison with the model eudicot Arabidopsis thaliana. We also discuss the agricultural application of genes controlling grass inflorescence development. PMID:24471834

  18. An updated conspectus of grasses of Punjab (India

    Directory of Open Access Journals (Sweden)

    Amarjit Singh Soodan

    2013-01-01

    Full Text Available Poaceae is the fourth largest family of the flowering plants. It includes about 700-800 genera and 11000-13000 species distributed worldwide. The family has unmatched ecological and economic importance. With its origin in the early cretaceous and major diversification in the mid Cenozoic, the family at present covers nearly a fifth of land surface and occurs in nearly all the habitats of the world. With a sub tropical ecology and an agrarian economy of Punjab, grasses comprise the most significant group in the region. Despite an overwhelming significance, taxonomic studies in grasses have not received sufficient attention in the region. It is only in the work of Sharma and Khosla (1989 that grass species have been classified into subfamilies and tribes. However, after the establishment of the Grass Phylogeny Working Group (GPWG the world has witnessed a renaissance in grass systematics. But, India remains an ‘undercollected’ country as far as grass diversity is concerned. Our work on the exploration and systematics of the grass flora of the region is an effort to consolidate and update the information on the diversity of grasses of the studied area. The present studies have brought the cumulative species number to 192 including seven new reports. The species representation of subfamilies is: Aristidoideae (5 Arundinoideae (5 Bambusoideae (4, Centothecoideae (1, Chloridoideae (55 Erhartoideae (3, Panicoideae (98 and Pooideae (21.

  19. Grass Lignin Acylation: p-Coumaroyl Transferase Activity and Cell Wall Characteristics of C3 and C4 Grasses

    Science.gov (United States)

    Grasses have always been a predominate source of nutritional energy for livestock systems around the world. Species belonging to the C3 and C4 grass types have recently been championed as feedstock sources for bioenergy production. Their ultimate use would be as a source of carbohydrate for fermenta...

  20. ESTABLISHMENT OF TRANSGENETIC HERBICIDE-RESISTANT CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NONAGRONOMIC HABITATS

    Science.gov (United States)

    Concerns about genetically modified (GM) crops include transgene flow to compatible wild species and unintended ecological consequences of potential transgene introgression. However, there has been little empirical documentation of establishment and distribution of transgenic pla...

  1. ESTABLISHMENT OF TRANSGENIC CREEPING BENTGRASS (AGROSTIS STOLONIFERA L.) IN NON-AGRONOMIC HABITATS

    Science.gov (United States)

    Concerns about genetically modified crops include transgene flow to compatible wild species and potential unintended ecological consequences associated with transgene introgression. To date, there has been little empirical documentation of the relative frequency of establishment...

  2. GRASS GIS Vector Processing: Towards GRASS 7

    Science.gov (United States)

    Metz, Markus; Landa, Martin; Petrasova, Anna; Petras, Vaclav; Chemin, Yann; Neteler, Markus

    2014-05-01

    The upcoming GRASS GIS 7 release improves not only raster processing and general design but the vector processing in the first place. GRASS GIS, as a topological GIS, recognizes that the topology plays the key role in the vector processing and analysis. Topology ensures that adjacent geographic components in a single vector map are related. In contrast to non-topological GIS, a border common to two areas exists only once and is shared between the two areas. Topological representation of vector data helps to produce and maintain vector maps with clean geometry as well as enables the user to perform certain analyses that can not be conducted with non-topological or spaghetti data. Non-topological vector data are automatically converted to a topological representation upon import. Further more, various cleaning tools exist to remove non-trivial topological errors. In the upcoming GRASS GIS 7 release the vector library was particularly improved to make it faster and more efficient with an improved internal vector file format. This new topological format reduces memory and disk space requirements, leading to a generally faster processing. Opening an existing vector requires less memory providing additionally support for large files. The new spatial index performs queries faster (compared to GRASS GIS 6 more than 10 times for large vectors). As a new option the user can select a file-based version of the spatial index for large vector data. All topological cleaning tools have been optimized with regard to processing speed, robustness, and system requirements. The topological engine comes with a new prototype for direct read/write support of Simple Features API/OGR. Additionally vector data can be directly exchanged with topological PostGIS 2 databases. Considering the wide spread usage of ESRI Shapefile, a non-topological format for vector data exchange, it is particularly advantageous that GRASS GIS 7 offers advanced cleaning tools. For power users and programmers, the

  3. Copper stress-induced changes in leaf soluble proteome of Cu-sensitive and tolerant Agrostis capillaris L. populations.

    Science.gov (United States)

    Hego, Elena; Vilain, Sébastien; Barré, Aurélien; Claverol, Stéphane; Dupuy, Jean-William; Lalanne, Céline; Bonneu, Marc; Plomion, Christophe; Mench, Michel

    2016-05-01

    Changes in leaf soluble proteome were explored in 3-month-old plants of metallicolous (M) and nonmetallicolous (NM) Agrostis capillaris L. populations exposed to increasing Cu concentrations (1-50 μM) to investigate molecular mechanisms underlying plant responses to Cu excess and tolerance of M plants. Plants were cultivated on perlite (CuSO4 spiked-nutrient solution). Soluble proteins, extracted by the trichloroacetic acid/acetone procedure, were separated with 2-DE (linear 4-7 pH gradient). Analysis of CCB-stained gels (PDQuest) reproducibly detected 214 spots, and 64 proteins differentially expressed were identified using LC-MS/MS. In both populations, Cu excess impacted both light-dependent (OEE, cytochrome b6-f complex, and chlorophyll a-b binding protein), and -independent (RuBisCO) photosynthesis reactions, more intensively in NM leaves (ferredoxin-NADP reductase and metalloprotease FTSH2). In both populations, upregulation of isocitrate dehydrogenase and cysteine/methionine synthases respectively suggested increased isocitrate oxidation and enhanced need for S-containing amino-acids, likely for chelation and detoxification. In NM leaves, an increasing need for energetic compounds was indicated by the stimulation of ATPases, glycolysis, pentose phosphate pathway, and Calvin cycle enzymes; impacts on protein metabolism and oxidative stress increase were respectively suggested by the rise of chaperones and redox enzymes. Overexpression of a HSP70 may be pivotal for M Cu tolerance by protecting protein metabolism. All MS data have been deposited in the ProteomeXchange with the dataset identifier PXD001930 (http//proteomecentral.proteomexchange.org/dataset/PXD001930). PMID:26900021

  4. Urban particulate pollution reduction by four species of green roof vegetation in a UK city

    Science.gov (United States)

    Speak, A. F.; Rothwell, J. J.; Lindley, S. J.; Smith, C. L.

    2012-12-01

    Urban particulate pollution in the UK remains at levels which have the potential to cause negative impacts on human health. There is a need, therefore, for mitigation strategies within cities, especially with regards to vehicular sources. The use of vegetation as a passive filter of urban air has been previously investigated, however green roof vegetation has not been specifically considered. The present study aims to quantify the effectiveness of four green roof species - creeping bentgrass (Agrostis stolonifera), red fescue (Festuca rubra), ribwort plantain (Plantago lanceolata) and sedum (Sedum album) - at capturing particulate matter smaller than 10 μm (PM10). Plants were grown in a location away from major road sources of PM10 and transplanted onto two roofs in Manchester city centre. One roof is adjacent to a major traffic source and one roof is characterised more by urban background inputs. Significant differences in metal containing PM10 capture were found between sites and between species. Site differences were explained by proximity to major sources. Species differences arise from differences in macro and micro morphology of the above surface biomass. The study finds that the grasses, A. stolonifera and F. rubra, are more effective than P. lanceolata and S. album at PM10 capture. Quantification of the annual PM10 removal potential was calculated under a maximum sedum green roof installation scenario for an area of the city centre, which totals 325 ha. Remediation of 2.3% (±0.1%) of 9.18 tonnes PM10 inputs for this area could be achieved under this scenario.

  5. Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition

    OpenAIRE

    Ahrens, Collin W.; Carol A Auer

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate ...

  6. Phylogenetic niche conservatism in C4 grasses.

    Science.gov (United States)

    Liu, Hui; Edwards, Erika J; Freckleton, Robert P; Osborne, Colin P

    2012-11-01

    Photosynthetic pathway is used widely to discriminate plant functional types in studies of global change. However, independent evolutionary lineages of C(4) grasses with different variants of C(4) photosynthesis show different biogeographical relationships with mean annual precipitation, suggesting phylogenetic niche conservatism (PNC). To investigate how phylogeny and photosynthetic type differentiate C(4) grasses, we compiled a dataset of morphological and habitat information of 185 genera belonging to two monophyletic subfamilies, Chloridoideae and Panicoideae, which together account for 90 % of the world's C(4) grass species. We evaluated evolutionary variance and covariance of morphological and habitat traits. Strong phylogenetic signals were found in both morphological and habitat traits, arising mainly from the divergence of the two subfamilies. Genera in Chloridoideae had significantly smaller culm heights, leaf widths, 1,000-seed weights and stomata; they also appeared more in dry, open or saline habitats than those of Panicoideae. Controlling for phylogenetic structure showed significant covariation among morphological traits, supporting the hypothesis of phylogenetically independent scaling effects. However, associations between morphological and habitat traits showed limited phylogenetic covariance. Subfamily was a better explanation than photosynthetic type for the variance in most morphological traits. Morphology, habitat water availability, shading, and productivity are therefore all involved in the PNC of C(4) grass lineages. This study emphasized the importance of phylogenetic history in the ecology and biogeography of C(4) grasses, suggesting that divergent lineages need to be considered to fully understand the impacts of global change on plant distributions. PMID:22569558

  7. A new cryptic species of Diatraea (Lepidoptera: Crambidae: Crambinae) feeding on eastern gama grass and a novel host association with a braconid (Hymenoptera) in the United States

    Science.gov (United States)

    The genus Diatraea currently consists of seven species in the United States, including Diatraea crambidoides (Grote), an economic pest of corn. Larvae of D. crambidoides are also reported to feed on sorghum (Sorghum bicolor (L.) Moench.), Johnsongrass (Sorghum halepense (L.) Pers.), sugar cane (Sacc...

  8. GUI development for GRASS GIS

    Directory of Open Access Journals (Sweden)

    Martin Landa

    2007-12-01

    Full Text Available This article discusses GUI development for GRASS GIS. Sophisticated native GUI for GRASS is one of the key points (besides the new 2D/3D raster library, vector architecture improvements, etc. for the future development of GRASS. In 2006 the GRASS development team decided to start working on the new generation of GUI instead of improving the current GUI based on Tcl/Tk.

  9. Establishing a grassland signature in veins: 18O in the leaf water of C3 and C4 grasses

    OpenAIRE

    Helliker, Brent R.; Ehleringer, James R.

    2000-01-01

    We show that 18O evaporative enrichment of bulk leaf water in grass species can be significantly more enriched than predicted by the Craig–Gordon model, with C4 grasses considerably more enriched than C3 grasses. Our results suggest that the unanticipated 18O leaf water enrichment of grasses is attributable to the progressive evaporative enrichment along parallel veins (a function of both leaf length and interveinal distance), a pattern that does not occur in Dicotyledonous species. We propos...

  10. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis) weeds and plant community composition.

    Science.gov (United States)

    Ahrens, Collin W; Auer, Carol A

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

  11. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis weeds and plant community composition.

    Directory of Open Access Journals (Sweden)

    Collin W Ahrens

    Full Text Available Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB and redtop (RT, where the glyphosate resistance (GR trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

  12. Epichloë grass endophytes in sustainable agriculture.

    Science.gov (United States)

    Kauppinen, Miia; Saikkonen, Kari; Helander, Marjo; Pirttilä, Anna Maria; Wäli, Piippa R

    2016-01-01

    There is an urgent need to create new solutions for sustainable agricultural practices that circumvent the heavy use of fertilizers and pesticides and increase the resilience of agricultural systems to environmental change. Beneficial microbial symbionts of plants are expected to play an important role in integrated pest management schemes over the coming decades. Epichloë endophytes, symbiotic fungi of many grass species, can protect plants against several stressors, and could therefore help to increase the productivity of forage grasses and the hardiness of turf grasses while reducing the use of synthetic pesticides. Indeed, Epichloë endophytes have successfully been developed and commercialized for agricultural use in the USA, Australia and New Zealand. Many of the host grass species originate from Europe, which is a biodiversity hotspot for both grasses and endophytes. However, intentional use of endophyte-enhanced grasses in Europe is virtually non-existent. We suggest that the diversity of European Epichloë endophytes and their host grasses should be exploited for the development of sustainable agricultural, horticultural and landscaping practices, and potentially for bioremediation and bioenergy purposes, and for environmental improvement. PMID:27249195

  13. Epichloë grass endophytes in sustainable agriculture.

    Science.gov (United States)

    Kauppinen, Miia; Saikkonen, Kari; Helander, Marjo; Pirttilä, Anna Maria; Wäli, Piippa R

    2016-01-01

    There is an urgent need to create new solutions for sustainable agricultural practices that circumvent the heavy use of fertilizers and pesticides and increase the resilience of agricultural systems to environmental change. Beneficial microbial symbionts of plants are expected to play an important role in integrated pest management schemes over the coming decades. Epichloë endophytes, symbiotic fungi of many grass species, can protect plants against several stressors, and could therefore help to increase the productivity of forage grasses and the hardiness of turf grasses while reducing the use of synthetic pesticides. Indeed, Epichloë endophytes have successfully been developed and commercialized for agricultural use in the USA, Australia and New Zealand. Many of the host grass species originate from Europe, which is a biodiversity hotspot for both grasses and endophytes. However, intentional use of endophyte-enhanced grasses in Europe is virtually non-existent. We suggest that the diversity of European Epichloë endophytes and their host grasses should be exploited for the development of sustainable agricultural, horticultural and landscaping practices, and potentially for bioremediation and bioenergy purposes, and for environmental improvement.

  14. Interspecific associations and community structure: A local survey and analysis in a grass community

    OpenAIRE

    WenJun Zhang

    2014-01-01

    Interspecific associations in the plant community may help to understand the self-organizing assembly and succession of the community. In present study, Pearson correlation, net correlation, Spearman rank correlation, and point correlation were used to detect the interspecific (inter-family) associations of grass species (families) using the sampling data collected in a grass community of Zhuhai, China. We found that most associations between grass species (families) were positive association...

  15. A novel grass hybrid to reduce flood generation in temperate regions

    OpenAIRE

    Christopher (Kit) J. A. Macleod; Humphreys, Mike W.; Whalley, W. Richard; Turner, Lesley; Binley, Andrew; Watts, Chris W.; Skøt, Leif; Joynes, Adrian; Hawkins, Sarah; King, Ian P.; O'Donovan, Sally; Haygarth, Phil M.

    2013-01-01

    We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared t...

  16. The effects of energy grass plantations on biodiversity

    Energy Technology Data Exchange (ETDEWEB)

    Semere, T.; Slater, F.

    2005-07-01

    The ecological impact on local wildlife of biomass plantations of three different species of grasses has been monitored in the years 2002 to 2004 inclusive at farms in Herefordshire UK. Two of the grasses were not native to Britain. Wildlife monitored included ground flora, beetles, insects, birds, small mammals, butterflies, bees and hoverflies. The results provide a baseline of biodiversity data from biomass farms in England, although due to poor crop growth, the data from the switch-grass plantation was incomplete. The surveys were carried out by Cardiff University supported financially by the DTI.

  17. The effects of energy grass plantations on biodiversity

    International Nuclear Information System (INIS)

    The ecological impact on local wildlife of biomass plantations of three different species of grasses has been monitored in the years 2002 to 2004 inclusive at farms in Herefordshire UK. Two of the grasses were not native to Britain. Wildlife monitored included ground flora, beetles, insects, birds, small mammals, butterflies, bees and hoverflies. The results provide a baseline of biodiversity data from biomass farms in England, although due to poor crop growth, the data from the switch-grass plantation was incomplete. The surveys were carried out by Cardiff University supported financially by the DTI

  18. Final Report: The Rhizosphere Association of the Nitrogen Fixing Bacterial Species Azotobacter Paspali with the Tropical Grass Paspalum Notatum: Specificity of Colonization and Contribution to Plant Nutrition, July 1, 1995 - February 14, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Christina K.

    1997-02-14

    The nitrogen fixing bacterium azotobacter paspali was first isolated from the roots of the sub-tropical grass, palpium notatum, and added to the clenus in 1996, by Dr. J. Dobereiner (Brazil). It is mentioned that this root association bacteria shows remarkable signs of host-plant specificity to one eco-type of this grass. This specificity is rare in non-symbiotic plant microbe interactions so far identified.

  19. A novel method to characterize silica bodies in grasses

    OpenAIRE

    Dabney, Clemon; Ostergaard, Jason; Watkins, Eric; Chen, Changbin

    2016-01-01

    Background The deposition of silicon into epidermal cells of grass species is thought to be an important mechanism that plants use as a defense against pests and environmental stresses. There are a number of techniques available to study the size, density and distribution pattern of silica bodies in grass leaves. However, none of those techniques can provide a high-throughput analysis, especially for a great number of samples. Results We developed a method utilizing the autofluorescence of si...

  20. Tolérance au Cu chez Agrostis capillaris L. : du phénotype vers les mécanismes moléculaires

    OpenAIRE

    Hego, Elena

    2014-01-01

    Des populations tolérante (métallicole: M) et sensible (non-métallicole: NM) d’Agrostis capillaris L. ont été exposées à des doses croissantes de Cu (1-50 μM) pour étudier la tolérance au Cu par une approche pluridisciplinaire. Selon les paramètres phénotypiques (biomasse, longueur des feuilles et symptômes visuels), les plantes M ont une meilleure croissance aux expositions supérieures à 10 μM Cu. Les concentrations en Cu des tissus reflètent une rétention racinaire (phénotype d’exclusion) e...

  1. Specific immunotherapy for common grass pollen allergies: pertinence of a five grass pollen vaccine.

    Science.gov (United States)

    Moingeon, Philippe; Hrabina, Maud; Bergmann, Karl-Christian; Jaeger, Siegfried; Frati, Franco; Bordas, Véronique; Peltre, Gabriel

    2008-01-01

    Patients throughout Europe are concomitantly exposed to multiple pollens from distinct Pooideae species. Given the overlap in pollination calendars and similar grain morphology, it is not possible to identify which grass species are present in the environment from pollen counts. Furthermore, neither serum IgE reactivity nor skin prick testing allow the identification of which grass species are involved in patient sensitisation. Due to their high level of amino acid sequence homology (e.g., >90% for group 1, 55-80% for group 5), significant cross-immunogenicity is observed between allergens from Pooideae pollens. Nevertheless, pollen allergens also contain species-specific T or B cell epitopes, and substantial quantitative differences exist in allergen (e.g., groups 1 and 5) composition between pollens from distinct grass species. In this context, a mixture of pollens from common and well-characterised Pooideae such as Anthoxanthum odoratum, Dactylis glomerata, Lolium perenne, Phleum pratense and Poa pratensis is suitable for immunotherapy purposes because (1) it has been validated, both in terms of safety and efficacy, by established clinical practice; (2) it reflects natural exposure and sensitisation conditions; (3) it ensures a consistent and well-balanced composition of critical allergens, thus extending the repertoire of T and B cell epitopes present in the vaccine.

  2. Chemotypic diversity of epichloae, fungal symbionts of grasses

    Science.gov (United States)

    The epichloid fungi - comprising sexual Epichlo€e species and asexual Neotyphodium species - are symbionts of cool-season grasses (subfamily Po€oideae), mostly vertically transmissible (seedborne), and well known for production of anti-herbivore alkaloids. Four classes of alkaloids are known to be p...

  3. Nitrogen losses from perennial grass species.

    NARCIS (Netherlands)

    Vazquez de Aldana, B.R.; Geerts, R.; Berendse, F.

    1996-01-01

    Nitrogen losses from plants may occur through a variety of pathways, but so far, most studies have only quantified losses of nutrients by above-ground litter production. We used 15 N pulse labelling to quantify total nitrogen losses from above- and below-ground plant parts. Using this method we were

  4. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Orby, P.V.; Skjoth, C. A.;

    2014-01-01

    of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season......In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods...

  5. Meadow-grass gall midge

    DEFF Research Database (Denmark)

    Hansen, Lars Monrad

    The area with meadow-grass (Poa pratensis, L.) grown for seed production in Den-mark is a significant proportion of the entire seed production. The meadow-grass gall midge (Mayetiola schoberi, Barnes 1958) is of considerable economic importance since powerful attacks can reduce the yield...... drastically. It overwinters as larvae in a puparium, in the soil, and begins to hatch on average in late April, but the time is de-pending on the temperature. Emergence of the meadow-grass gall midge in spring takes place over a 2-3 week period. Beginning of emergence of the meadow-grass gall midge takes...... maximum. Therefore, the spraying frequency could be lowered signifi-cantly and in many cases lowered to only one insecticide application in meadow-grass every year....

  6. WHEAT GRASS HEALTH BENEFITS

    Directory of Open Access Journals (Sweden)

    Akula Annapurna

    2013-10-01

    Full Text Available Nutraceutical is a food or food product that provides health and medical benefits, including the preventionand treatment of disease. Nutraceuticals are the products typically claim to prevent chronic diseases, improve health,delay the aging process, and increase life expectancy.Let us know something about one such nutraceutical.Wheatgrass is a commonly found herb in India contains enzymes like protease, cytrochrome, amylase, lipase,transhydrogenase and SOD (super oxide dismutase. Besides these enzymes, it also contains all the essential aminoacids especially alanine, asparatic acid, glutamic acid, arginine and serine, which are helpful in providing good amountof protein in body which builds and repair tissues. Wheatgrass contains chlorophyll and flavonoids in good amount.It also contains vitamins like vitamin A, vitamin C, and vitamin E and minerals like iron, calcium and magnesium.Chlorophyll has been shown to build red blood cells quickly,cures anemia, normalise blood pressure by dilating theblood vessels. Chlorophyll has been shown to produce an unfavourable environment for bacterial growth in the bodyand therefore effective in increasing the body's resistance to illness. Probably the most important benefit ofwheatgrass is, it is a cancer fighting agent. Many people strongly believe that the benefits of wheatgrass on cancerare real and that consuming wheat grass can help in the treatment and even in the prevention of cancer. Wheatgrassproduces an immunization effect against many dietary carcinogens..Additional benefits of wheatgrass are bettercomplexion and a healthy glow. The slowing of graying hair is also a benefit believed to come from wheatgrass. Wecan grow wheat grass in small cups, pots and trays very conveniently in our homes, so that we will have fresh juiceand powder with minimum cost.

  7. TILLING in forage grasses for gene discovery and breeding improvement.

    Science.gov (United States)

    Manzanares, Chloe; Yates, Steven; Ruckle, Michael; Nay, Michelle; Studer, Bruno

    2016-09-25

    Mutation breeding has a long-standing history and in some major crop species, many of the most important cultivars have their origin in germplasm generated by mutation induction. For almost two decades, methods for TILLING (Targeting Induced Local Lesions IN Genomes) have been established in model plant species such as Arabidopsis (Arabidopsis thaliana L.), enabling the functional analysis of genes. Recent advances in mutation detection by second generation sequencing technology have brought its utility to major crop species. However, it has remained difficult to apply similar approaches in forage and turf grasses, mainly due to their outbreeding nature maintained by an efficient self-incompatibility system. Starting with a description of the extent to which traditional mutagenesis methods have contributed to crop yield increase in the past, this review focuses on technological approaches to implement TILLING-based strategies for the improvement of forage grass breeding through forward and reverse genetics. We present first results from TILLING in allogamous forage grasses for traits such as stress tolerance and evaluate prospects for rapid implementation of beneficial alleles to forage grass breeding. In conclusion, large-scale induced mutation resources, used for forward genetic screens, constitute a valuable tool to increase the genetic diversity for breeding and can be generated with relatively small investments in forage grasses. Furthermore, large libraries of sequenced mutations can be readily established, providing enhanced opportunities to discover mutations in genes controlling traits of agricultural importance and to study gene functions by reverse genetics. PMID:26924175

  8. Effect of mixing low palatable grasses and ipil ipil leaves on forage quality

    International Nuclear Information System (INIS)

    The study was conducted at the National Agricultural Research Centre, Islamabad, Pakistan to investigate the impact of mixing low palatable grasses namely Heteropogon contortus, Desmostachya bipinnata, Sorghum halepense and Chrysopogon aucheri with tree leaves of Leucaena leucocephala (Ipil ipil) in the ratio of 75:25, 50:50, 25:75, along with sole species on their chemical composition. Samples were analyzed for proximate parameters (crude protein (CP), crude fiber (CF), total ash and ether extract (EE)). The results revealed that there were significant differences in dry matter (DM) among different grasses. DM content of low palatable grasses was generally high (70-75%) as compared to Ipil ipil leaves (45-55%). DM content among mixtures was also variable. For the treatment grass 75% + Ipil ipil 25%, DM range was 65-70%, for grass 50% + Ipil ipil 50%, it was 60-65% and for grass 25% + Ipil ipil 75%, it was 55%. The CP value of the treatments showed significant variation ranging from less than 10% in grasses to almost 30% in pure Ipil ipil leaves. The mixtures had CP content corresponding to proportions of grasses and legume tree leaves. The CF values also varied significantly among the treatments. Grasses had in general higher CF content than legume leaves. It can be concluded that addition of Ipil ipil leaves to grasses improved overall nutrition especially CP of the feed. (author)

  9. Anti-Insect Properties of Grass Fungal Endophytes for Plant Resistance to Insects

    Science.gov (United States)

    Many temperate grass species host Epichloë and Neotyphodium endophytic fungi that produce alkaloids with anti-mammalian and anti-insect properties. Ergot and lolitrem alkaloid production by endophyte-infected (E+) grasses can have deleterious effects on grazing livestock, whereas insecticidal alkal...

  10. Case report of chondroma in a grass carp (Ctenopharyngodon idella)

    Science.gov (United States)

    Mesbah, Mehrzad; Rezaie, Annahita; Tulaby Dezfuly, Zahra

    2016-01-01

    The grass carp (Ctenopharyngodon idella) is a herbivorous, freshwater fish species of the family Cyprinidae, and the only species of the genus Ctenopharyngodon. Neoplasms in fishes are generally less aggressive than neoplasms in mammals and are most commonly discrete, focal and benign neoplasms. A 3-year-old grass carp with a big mass on the vertebrae was referred to the clinic. According to the owner’s statements, the fish had no signs of lethargy, ataxia and abnormal behaviors. The size of the mass was 7 × 6 × 6 cm. It cut hardly with audible sounds. The consistency of the mass was as hard as a cartilage. Microscopic examination revealed numerous irregular crests of hyaline cartilage beneath the skin. According to histopathologic characteristics, chondroma on the vertebrae of grass carp was diagnosed.

  11. EGRADATION CHARACTERISTICS OF SOME SUDANESE GRASSES AND GAS PRODUCTION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A.O. Idris

    2012-05-01

    Full Text Available Eighteen plant species, three ingredients, and six diets were studied for their degradation characteristics, using gas production techniques. The palatable grasses were selected during the rainy season from the range land of Kordofan, Sudan. The ingredients were Roselle seeds, Sorghum grain and Groundnut cake. The samples were incubated for 4, 8, 12, 24, 48, 72 and 96 h, using rumen inoculum of three of the sheep used for the nylon bag. The results showed a large variation between the different plant species in the gas volume. The potential gas volume reflected the presence of anti-nutritional factors. Gas production from the ingredients indicated that sorghum grain recorded the highest gas production volume. The gas production at different time intervals showed increased degradability in the grasses, diets and the ingredients. Eragrostis tremula could be used as reference forage in evaluating the organic matter digestibility and energy density of grasses and Farsefia longisiliqua as a reference for crude protein.

  12. Grass fungal endophytes and uses thereof

    Science.gov (United States)

    Craven, Kelly

    2015-03-10

    The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.

  13. Edge effect on carabid assemblages along forest-grass transects

    Directory of Open Access Journals (Sweden)

    T. Magura

    2001-02-01

    Full Text Available During 1997 and 1998, we have tested the edge-effect for carabids along oak-hornbeam forest-grass transects using pitfall traps in Hungary. Our hypothesis was that the diversity of carabids will be higher in the forest edge than in the forest interior. We also focused on the characteristic species of the habitats along the transects and the relationships between their distribution and the biotic and abiotic factors.

    Our results proved that there was a significant edge effect on the studied carabid communities: the Shannon diversity increased significantly along the transects from the forest towards the grass. The diversity of the carabids were significantly higher in the forest edge and in the grass than in the forest interior. The carabids of the forest, the forest edge and the grass are separated from each other by principal coordinates analysis and by indicator species analysis (IndVal, suggesting that each of the three habitats has a distinct species assemblages. There were 5 distinctive groups of carabids: 1 habitat generalists, 2 forest generalists, 3 species of the open area, 4 forest edge species, and 5 forest specialists. It was demonstrated by multiple regression analyses, that the relative air moisture, temperature of the ground, the cover of leaf litter, herbs, shrubs and canopy cover, abundance of the carabids’ preys are the most important factors determining the diversity and spatial pattern of carabids along the studied transects.

  14. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula;

    2012-01-01

    of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods......, we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...

  15. Grass and weed killer poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002838.htm Grass and weed killer poisoning To use the sharing features on this page, please enable JavaScript. Many weed killers contain dangerous chemicals that are harmful if swallowed. ...

  16. Factors influencing seed germination in Cerrado grasses

    Directory of Open Access Journals (Sweden)

    Rosana Marta Kolb

    2016-03-01

    Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

  17. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  18. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies.

    Science.gov (United States)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  19. POSSIBLE MECHANISMS OF THE EXCLUSION OF JOHNSON GRASS BY TALL GRASS PRAIRIES

    Directory of Open Access Journals (Sweden)

    Marilyn A. Semtner

    2012-12-01

    Full Text Available Historically, plant distribution typically has been studied with the purpose of learning why a species grows and survives where it does; but why a species does not survive in a particular habitat has rarely been studied, although it may be just as important. According to the US Department of Agriculture, Johnsongrass [Sorghum halepense (L. Pers.; formerly Johnson grass] is listed as an agricultural pest in most states south of the 42nd parallel. Control of Johnsongrass inagricultural fields involves various labor intensive cultural, mechanical, and chemical means. Release of a bio-control agent has not been suitable for intensively cropped areas. An agriculturally important weed and prominent member of early stage secondary succession, Johnsongrass is not present in later stages of prairie succession. Various environmental factors (biotic and abiotic that might be involved in restricting Johnsongrass survival were examined in this research. In two sites in Oklahoma, soil conditions were found to be more favorable for survival and growth of Johnsongrass in undisturbed prairie than in the disturbed areas in which Johnsongrass was found vigorously growing. However, even when its rhizomes were introduced into mature prairie, Johnsongrass did not thrive. In laboratory and field trials, presence of the living dominant prairie grasses or leachate from living or dead leaf blades seemed to influence growth and survival of Johnsongrass rhizomes. The prairie grasses, little bluestem [Schizachyrium scoparium (Michx. Nash] and Indian grass [Sorghastrum nutans (L. Nash], seem to play a similarallelopathic role in restricting the growth of Johnsongrass to outside of the prairies. Looking at this past study might lead to new methods for the future. (Semtner 2012

  20. How much gas can we get from grass?

    International Nuclear Information System (INIS)

    Highlights: ► We highlight the various results for biomethane potential that may be obtained from the same grass silage. ► The results indicated that methane potential varied from 350 to 493 L CH4 kg−1 VS added for three different BMP procedures. ► We compare two distinct digestion systems using the same grass. ► A two stage wet system achieved 451 L CH4 kg−1 VS added over a 50 day retention period. ► A two phase system achieved 341 L CH4 kg−1 VS added at a 30 day retention time. -- Abstract: Grass biomethane has been shown to be a sustainable gaseous transport biofuel, with a good energy balance, and significant potential for economic viability. Of issue for the designer is the variation in characteristics of the grass depending on location of source, time of cut and species. Further confusion arises from the biomethane potential tests (BMP) which have a tendency to give varying results. This paper has dual ambitions. One of these is to highlight the various results for biomethane potential that may be obtained from the same grass silage. The results indicated that methane potential from the same grass silage varied from 350 to 493 L CH4 kg−1 VS added for three different BMP procedures. The second ambition is to attempt to compare two distinct digestion systems again using the same grass: a two stage continuously stirred tank reactor (CSTR); and a sequentially fed leach bed reactor connected to an upflow anaerobic sludge blanket (SLBR–UASB). The two engineered systems were designed, fabricated, commissioned and operated at small pilot scale until stable optimal operating conditions were reached. The CSTR system achieved 451 L CH4 kg−1 VS added over a 50 day retention period. The SLBR–UASB achieved 341 L CH4 kg−1 VS added at a 30 day retention time.

  1. Heavy metal levels of pasture grasses in metropolitan area

    Science.gov (United States)

    Luilo, G. B.; Othman, O. C.

    2003-05-01

    Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

  2. Vegetative Hyphal Fusion and Subsequent Nuclear Behavior in Epichloë Grass Endophytes

    OpenAIRE

    Jun-Ya Shoji; Charlton, Nikki D.; Mihwa Yi; Young, Carolyn A.; Craven, Kelly D.

    2015-01-01

    Epichloë species (including the former genus Neotyphodium) are fungal symbionts of many agronomically important forage grasses, and provide their grass hosts with protection from a wide range of biotic and abiotic stresses. Epichloë species include many interspecific hybrids with allodiploid-like genomes, which may provide the potential for combined traits or recombination to generate new traits. Though circumstantial evidence suggests that such interspecific hybrids might have arisen from nu...

  3. TESTING OF INSECT MICROSPORIDIAN (MICROSPORA: NOSEMATIDAE) IN NONTARGET AQUATIC SPECIES

    Science.gov (United States)

    This paper reports results of single-species tests with the mosquito microsporidian Nosema algerae and the orthopteran microsporidian N. locustae on nontarget aquatic organisms. rganisms tested were the freshwater grass shrimp (Palaemonetes kadiakensis), the estuarine grass shrim...

  4. Climate change and the invasion of California by grasses

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Dangremond, Emily

    2012-01-01

    differences between groups allows us to predict changes in the exotic-native balance under climate change scenarios. Exotic species are more likely to be annual, taller, with larger leaves, larger seeds, higher specific leaf area, and higher leaf N percentage than native species. Across the state, all......Over the next century, changes in the global climate are expected to have major consequences for plant communities, possibly including the exacerbation of species invasions. We evaluated this possibility in the grass flora of California, which is economically and ecologically important and heavily...... invaded. We used a novel, trait-based approach involving two components: identifying differences in trait composition between native and exotic components of the grass flora and evaluating contemporary trait–climate relationships across the state. The combination of trait–climate relationships and trait...

  5. Genetic modification of wetland grasses for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Czako, M.; Liang Dali; Marton, L. [Dept. of Biological Sciences, Univ. of South Carolina, Columbia, SC (United States); Feng Xianzhong; He Yuke [National Lab. of Plant Molecular Genetics, Shanghai Inst. of Plant Physiology, Chinese Academy of Sciences, Shanghai, SH (China)

    2005-04-01

    Wetland grasses and grass-like monocots are very important natural remediators of pollutants. Their genetic improvement is an important task because introduction of key transgenes can dramatically improve their remediation potential. Tissue culture is prerequisite for genetic manipulation, and methods are reported here for in vitro culture and micropropagation of a number of wetland plants of various ecological requirements such as salt marsh, brackish water, riverbanks, and various zones of lakes and ponds, and bogs. The monocots represent numerous genera in various families such as Poaceae, Cyperaceae, Juncaceae, and Typhaceae. The reported species are in various stages of micropropagation and Arundo donax is scaled for mass propagation for selecting elite lines for pytoremediation. Transfer of key genes for mercury phytoremediation into the salt marsh cordgrass (Spartina alterniflora) is also reported here. All but one transgenic lines contained both the organomercurial lyase (merB) and mercuric reductase (merA) sequences showing that co-introduction into Spartina of two genes from separate Agrobacterium strains is possible. (orig.)

  6. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....

  7. Bioenergy production from roadside grass

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Ehimen, Ehiazesebhor Augustine; Holm-Nielsen, Jens Bo

    2014-01-01

    This paper presents a study of the feasibility of utilising roadside vegetation for biogas production in Denmark. The potential biomass yield, methane yields, and the energy balances of using roadside grass for biogas production was investigated based on spatial analysis. The results show that th...

  8. Chemicals Reduce Need To Mow Grass

    Science.gov (United States)

    Humphrys, Brooks; Farley, Max; Gast, Larry J.

    1993-01-01

    Brief report discusses use of herbicides Roundup(R), Campaign(R), and Oust(R) to retard growth of Argentine bahia grass. Herbicide applied by use of spraying apparatus pulled by tractor. "Chemical mowing" keeps grass at "freshly mowed" height with less mechanical mowing. Applied to grass on shoulders of roads, reducing time spent on mowing.

  9. Gene Expression Profiling of Grass Carp (Ctenopharyngodon idellus) and Crisp Grass Carp

    OpenAIRE

    Ermeng Yu; Jun Xie; Guangjun Wang; Deguang Yu; Wangbao Gong; Zhifei Li; Haiying Wang; Yun Xia; Nan Wei

    2014-01-01

    Grass carp (Ctenopharyngodon idellus) is one of the most important freshwater fish that is native to China, and crisp grass carp is a kind of high value-added fishes which have higher muscle firmness. To investigate biological functions and possible signal transduction pathways that address muscle firmness increase of crisp grass carp, microarray analysis of 14,900 transcripts was performed. Compared with grass carp, 127 genes were upregulated and 114 genes were downregulated in crisp grass c...

  10. Native grass, sedge and legume establishment and legume-grass competition at a coal mine in the Rocky Mountains of southeastern British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, C.R. [Myosotis Ecological Consulting, Blairmore, AB (Canada)

    1997-09-01

    Seed establishment and seedling persistence of seven native high elevation legume, twelve grass and two sedge species on coal mine spoil were studied over a period of five years. Three separate direct seeding experiments were established: (1) native legume, (2) native grass and sedge and (3) native legume - agronomic grass competition. In the legume experiment, field seed germination percentages ranged from 41-65%. At the end of the recording period, survivorship ranged from 20% (Hedysarum sulphurescens) to 58% (Oxytropis podocarpa and Oxytropis sericea). Percent cover increased each year for all species and ranged from 10-38% at the end of the fifth growing season. Recruitment from seed was small for each species (n{lt} 15). In the grass/sedge experiment, field seed germination percentages ranged from 5-61%. At the end of the recording period, abundances ranged from 3% (Festuca scabrella) to 74% (festuca brachyphylla). Seedling mortality varied with species but, in general, declined after three years. Percent cover increased each year for all species and ranged from 5-48% at the end of the fifth growing season. Recruitment from seed ranged from 4% (Festuca scabrella) to 24% (Festuca brachyphylla) individuals. Competitive dominance or exclusion of the native legumes by agronomic grasses was also studied. Legume co-existence was not constrained in the agronomic bunchgrass - native legume sward but was constrained in the rhizomatous grass sward - native legume sward. The amount of above-ground biomass production constrained the growth of the lower relative growth rate (RGR) native legumes. Oxytropis sericea, Astragalus alpinus, Astragalus bourgovii and Astragalus vexilliflexus var. nubilus were least constrained by the higher densities of grasses. 70 refs., 6 figs., 3 tabs.

  11. Recuperação de larvas infectantes de Trichostrongylus colubriformis em três espécies de gramíneas contaminadas no verão Recovery of Trichostrongylus colubriformis infective larvae from three grass species contaminated in summer

    Directory of Open Access Journals (Sweden)

    Raquel A. da Rocha

    2008-12-01

    , Cynodon dactilon cv. Coast-cross, and Panicum maximum cv. Aruana, were used in the study, totaling two plots for each species. Each plot (32.4 m² was divided into 36 subplots (30 x 30 cm in order to allow six replicates per forage species and per herbage height in each week of material collection. Larval recovery was evaluated from middle summer to middle autumn under the effect of two forage paring heights: low, 5 cm, and high, 30 cm. The paring was carried out immediately before the fecal samples with T. colubriformis eggs, taken from sheep, were deposited on pasture in 05/Feb/2004. Feces and forage collection was performed one, two, four, eight, 12 and 16 weeks after feces deposition in the experimental plots. Forage grass height was measured in each subdivision immediately before the collections. The forage sample was cut, close to the soil, from an area delimited with a circle with a 10-cm radius. The feces were collected from the subplots. The number of infective larvae recovered from pasture was very small in compa6rison with the amount of larvae produced in cultures maintained in laboratory (maximum 6.7% on Aruana grass with 30 cm. L3 recovery rates from fecal samples were bigger when the feces were deposited on high grass (measuring 30 cm - P 0.05. Among the forage species, the Aruana grass was the one that, in general, harbored the biggest concentrations of infective T. colubriformis larvae.

  12. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L.; Huang, Z.Z. (Department of Environmental Horticulture, University of California, (United States))

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species.

  13. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity.

    Science.gov (United States)

    Wu, L; Huang, Z Z

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species.

  14. Interspecific associations and community structure: A local survey and analysis in a grass community

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2014-09-01

    Full Text Available Interspecific associations in the plant community may help to understand the self-organizing assembly and succession of the community. In present study, Pearson correlation, net correlation, Spearman rank correlation, and point correlation were used to detect the interspecific (inter-family associations of grass species (families using the sampling data collected in a grass community of Zhuhai, China. We found that most associations between grass species (families were positive associations. The competition/interference/niche separation between grass species (families was not significant. A lot of pairs of grass species and families with statistically significant interspecific (inter-family associations based on four correlation measures were discovered. Cluster trees for grass species/families were obtained by using cluster analysis. Relationship among positive/negative associations, interspecific relationship and community succession/stability/robustness was discussed. I held that species with significant positive or negative associations are generally keystone species in the community. Although both negative and positive associations occur in the community succession, the adaptation and selection will finally result in the successful coexistence of the species with significant positive associations in the climax community. As the advance of community succession, the significant positive associations increase and maximize in climax community, and the significant negative associations increase to a maximum and then decline into climax community. Dominance of significant positive associations in the climax community means the relative stablility and equilibrium of the community. No significant associations usually account for the majority of possible interspecific associations at each phase of community succession. They guarantee the robustness of community. They are candidates of keystone species. Lose of some existing keystone species might be

  15. Emerging technologies advancing forage and turf grass genomics.

    Science.gov (United States)

    Kopecký, David; Studer, Bruno

    2014-01-01

    Grassland is of major importance for agricultural production and provides valuable ecosystem services. Its impact is likely to rise in changing socio-economic and climatic environments. High yielding forage grass species are major components of sustainable grassland production. Understanding the genome structure and function of grassland species provides opportunities to accelerate crop improvement and thus to mitigate the future challenges of increased feed and food demand, scarcity of natural resources such as water and nutrients, and high product qualities. In this review, we will discuss a selection of technological developments that served as main drivers to generate new insights into the structure and function of nuclear genomes. Many of these technologies were originally developed in human or animal science and are now increasingly applied in plant genomics. Our main goal is to highlight the benefits of using these technologies for forage and turf grass genome research, to discuss their potentials and limitations as well as their relevance for future applications. PMID:24309540

  16. A novel grass hybrid to reduce flood generation in temperate regions

    Science.gov (United States)

    Macleod, Christopher (Kit) J. A.; Humphreys, Mike W.; Whalley, W. Richard; Turner, Lesley; Binley, Andrew; Watts, Chris W.; Skøt, Leif; Joynes, Adrian; Hawkins, Sarah; King, Ian P.; O'Donovan, Sally; Haygarth, Phil M.

    2013-01-01

    We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared to a leading UK nationally recommended L. perenne cultivar and by 43% compared to F. pratensis over a two year field experiment. We present evidence that the reduced runoff from this Festulolium cultivar was due to intense initial root growth followed by rapid senescence, especially at depth. Hybrid grasses of this type show potential for reducing the likelihood of flooding, whilst providing food production under conditions of changing climate. PMID:23619058

  17. Epichloe endophytes alter inducible indirect defences in host grasses.

    Directory of Open Access Journals (Sweden)

    Tao Li

    Full Text Available Epichloë endophytes are common symbionts living asymptomatically in pooid grasses and may provide chemical defences against herbivorous insects. While the mechanisms underlying these fungal defences have been well studied, it remains unknown whether endophyte presence affects the host's own defences. We addressed this issue by examining variation in the impact of Epichloë on constitutive and herbivore-induced emissions of volatile organic compounds (VOC, a well-known indirect plant defence, between two grass species, Schedonorus phoenix (ex. Festuca arundinacea; tall fescue and Festuca pratensis (meadow fescue. We found that feeding by a generalist aphid species, Rhopalosiphum padi, induced VOC emissions by uninfected plants of both grass species but to varying extents, while mechanical wounding failed to do so in both species after one day of damage. Interestingly, regardless of damage treatment, Epichloë uncinata-infected F. pratensis emitted significantly lower quantities of VOCs than their uninfected counterparts. In contrast, Epichloë coenophiala-infected S. phoenix did not differ from their uninfected counterparts in constitutive VOC emissions but tended to increase VOC emissions under intense aphid feeding. A multivariate analysis showed that endophyte status imposed stronger differences in VOC profiles of F. pratensis than damage treatment, while the reverse was true for S. phoenix. Additionally, both endophytes inhibited R. padi population growth as measured by aphid dry biomass, with the inhibition appearing greater in E. uncinata-infected F. pratensis. Our results suggest, not only that Epichloë endophytes may play important roles in mediating host VOC responses to herbivory, but also that the magnitude and direction of such responses may vary with the identity of the Epichloë-grass symbiosis. Whether Epichloë-mediated host VOC responses will eventually translate into effects on higher trophic levels merits future investigation.

  18. Comparative Histomorphological Studies on Oesophagus of Catfish and Grass Carp

    OpenAIRE

    Enas A. Abd El Hafez; Doaa M. Mokhtar; Alaa Sayed Abou-Elhamd; Ahmed Hassan S. Hassan

    2013-01-01

    The present work was carried out on 40 specimens of oesophaguses of both sexes of catfish (carnivorous fish) and grass carp (herbivorous fish) in order to observe the morphological and histological differences between the two species. Oesophagus of catfish was divided into 2 parts: anterior and posterior ones. The anterior part of the oesophagus of catfish was characterized by the presence of numerous mucosal folds. It was lined by stratified epithelium with goblet cells. In addition to club ...

  19. Study on the Reproductive Allocation of Four Kinds of Cluster-type Grass Ground Biomass in Changbai Mountain%长白山区4种丛型禾草地上生物量生殖分配研究

    Institute of Scientific and Technical Information of China (English)

    宋金枝; 李海燕; 夏广清; 孙忠林

    2011-01-01

    [Objective] The research aimed to study the reproductive allocation of four kinds of cluster-type grass ground biomass. [Method] The four kinds of cluster-type grass which were Poa pratensis, Elymus sibiricus, Agrostis clavata and Roeqneria kamojiowi in Changbai Mountain were the research objects. The proportions of vegetative shoot and reproductive shoot component biomass to total ground biomass in every population were counted. [ Result ] The allocation proportions of four kinds of cluster-type grass reproductive shoot biomass were higher and were basically above 85%. In the components of reproductive shoot, the reproductive allocation proportion of reproductive shoot stem biomass was greater (75% -90% ), which illustrated that the four kinds of cluster-type grass done the asexual reproduction by generating the new one from the stem base under the ground. [ Conclusion ] The general rule of ground total biomass reproductive allocation of cluster-type grass was initially revealed, which provided the theory basis for the plant reproductive ecology, the reasonable utilization and scientific management of lawn.%[目的]研究4种丛型禾草地上生物量的生殖分配.[方法]以长白山区的4种丛型禾草:草地早熟禾(Poa pratensis)、垂穗披碱草(Elymus sibiricus)、华北翦股颖(Agrostis clavata)和鹅观草(Roeqneria kamojiowi)为研究对象,计算各种群营养枝和生殖枝构件生物量占地上总生物量的百分比.[结果]4种丛型禾草生殖枝生物量的分配比例较高,基本都在85%以上.在生殖枝构件中,生殖枝茎杆生物量的生殖分配比例较大(75%-90%),说明这4种丛型禾草主要是以地面下茎基部分蘖出新个体进行无性生殖.[结论]初步揭示了丛型禾草地上总生物量生殖分配的一般规律,为植物生殖生态学以及草地的合理利用和科学管理提供理论依据.

  20. Gene expression in grass ovaries infected with seed born fungal endophyte Neotyphodium occultans analyzed by a next-generation sequencing system

    Science.gov (United States)

    Fungal endophytes of the genus Neotyphodium form symbiotic associations with many grass species of the subfamily Pooideae, including some important forage and turf species such as Lolium grasses. The endophytes are maintained in host plant communities by seed transmission from maternal plants to off...

  1. Symbiotic grasses: A review of basic biology of forage grass fungal endophytes

    Science.gov (United States)

    The fungal endophytes associated with grasses are the fundamental reason for the basic successes of several pasture grasses, notable tall fescues, and perennial ryegrass. Tall fescue and perennial ryegrass fungal endophytes, Neotyphodium coenophialum and N. lolii, respectively, and their relatives ...

  2. The potential of C4 grasses for cellulosic biofuel production

    Directory of Open Access Journals (Sweden)

    Tim eWeijde

    2013-05-01

    Full Text Available With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulose feedstock for biofuel production is discussed. These include three important field crops - maize, sugarcane and sorghum - and two undomesticated perennial energy grasses - miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of

  3. Soil phosphorus dynamics as affected by Congo grass and P fertilizer

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2014-08-01

    Full Text Available Some plant species can change soil phosphorus (P availability and this may be an important tool in managing tropical high fixing phosphorus soils. An experiment was conducted to evaluate phosphorus transformations in the soil and phosphatase activity during periods of Congo grass (Brachiaria ruziziensis, Germain et Evrard growth in two tropical soils receiving 20, 40, 80, 160 mg dm-3 of inorganic P. Plants were grown for 84 days in 8-L pots. Acid phosphatase activity, P in the microbial mass, soil organic and inorganic P and P accumulation by Congo grass were evaluated. Phosphorus fertilization increased soil P availability, Congo grass yields and P accumulation in the plant. On average, less labile P forms in the soil were not changed by Congo grass; however, the P in the soil extracted with HCl (P-Ca - non labil form decreased. This decrease may have resulted from the combination of the presence of grass and phosphatase capacity to dissolve less available P in the soil. Thus, soil exploration by Congo grass roots and the subsequent extraction of calcium phosphate may have increased the P concentration in the plant tissue. Despite the decrease in the P extracted from the soil with HCl resulting in increased labile P forms in the soil, the effect of Congo grass on the availability of P depends on the soil type.

  4. A consensus linkage map of the grass carp (Ctenopharyngodon idella based on microsatellites and SNPs

    Directory of Open Access Journals (Sweden)

    Li Jiale

    2010-02-01

    Full Text Available Abstract Background Grass carp (Ctenopharyngodon idella belongs to the family Cyprinidae which includes more than 2000 fish species. It is one of the most important freshwater food fish species in world aquaculture. A linkage map is an essential framework for mapping traits of interest and is often the first step towards understanding genome evolution. The aim of this study is to construct a first generation genetic map of grass carp using microsatellites and SNPs to generate a new resource for mapping QTL for economically important traits and to conduct a comparative mapping analysis to shed new insights into the evolution of fish genomes. Results We constructed a first generation linkage map of grass carp with a mapping panel containing two F1 families including 192 progenies. Sixteen SNPs in genes and 263 microsatellite markers were mapped to twenty-four linkage groups (LGs. The number of LGs was corresponding to the haploid chromosome number of grass carp. The sex-specific map was 1149.4 and 888.8 cM long in females and males respectively whereas the sex-averaged map spanned 1176.1 cM. The average resolution of the map was 4.2 cM/locus. BLAST searches of sequences of mapped markers of grass carp against the whole genome sequence of zebrafish revealed substantial macrosynteny relationship and extensive colinearity of markers between grass carp and zebrafish. Conclusions The linkage map of grass carp presented here is the first linkage map of a food fish species based on co-dominant markers in the family Cyprinidae. This map provides a valuable resource for mapping phenotypic variations and serves as a reference to approach comparative genomics and understand the evolution of fish genomes and could be complementary to grass carp genome sequencing project.

  5. L-band radar scattering from grass

    Science.gov (United States)

    Chauhan, N.; O'Neill, P.; Le Vine, D.; Lang, R.; Khadr, N.

    1992-01-01

    A radar system based on a network analyzer has been developed to study the backscatter from vegetation. The radar is operated at L-band. Radar measurements of a grass field were made in 1991. The radar returns from the grass were measured at three incidence angles. Ground truth and canopy parameters such as blade and stem dimensions, moisture content of the grass and the soil, and blade and stem density, were measured. These parameters are used in a distorted Born approximation model to compute the backscatter coefficients from the grass layer. The model results are compared with the radar data.

  6. Transfer of radiocaesium to barley, rye grass and pea

    International Nuclear Information System (INIS)

    In areas with intensive farming, as in Denmark, it is of great interest to identify possible countermeasures to be taken in order to reduce the longterm effects of radioactive contamination of arable land. The most important longer-lived radionuclides from the Chernobyl were 137Cs and 134Cs. The aim of the present project was to identify crops with relatively low or high root uptake of these two isotopes. Although such differences may be small, a shift in varieties might be a cost-effective way to reduce collective doses. The experiment was carried out at Risoe National Laboratory in the summer of 1988. The species used were: spring barley (Hordeum vulgare L) varieties: Golf, Apex, Anker, Sila; Perennial rye grass (Lolium perenne L.) varieties: Darbo (early) and Patoro (late); Italian rye-grass (Lolium multiflorum) variety: Prego; and pea (Pisum arvense L.) variety: Bodil. Each crop was grown in two types of soil, a clay-loam and an organic soil. 137Cs was added to the clay-loam. The organic soil, which was contaminated with 137Cs from the Chernobyl accident, was supplied with 134Cs. Sila barley and Italian rye-grass were identified among the species tested as plants with a relative high uptake of radio-caesium. (author)

  7. Comparative Histomorphological Studies on Oesophagus of Catfish and Grass Carp

    Directory of Open Access Journals (Sweden)

    Enas A. Abd El Hafez

    2013-01-01

    Full Text Available The present work was carried out on 40 specimens of oesophaguses of both sexes of catfish (carnivorous fish and grass carp (herbivorous fish in order to observe the morphological and histological differences between the two species. Oesophagus of catfish was divided into 2 parts: anterior and posterior ones. The anterior part of the oesophagus of catfish was characterized by the presence of numerous mucosal folds. It was lined by stratified epithelium with goblet cells. In addition to club cells were observed in between the stratified epithelium. Scanning electron examination of the oesophageal epithelium of catfish demonstrated the presence of microvilli and fingerprint-like microridges in the superficial cell layer. The posterior part of the oesophagus of catfish was characterized by simple columnar mucus-secreting epithelium. The oesophagus of grass carp had shown the same structure along its entire length. It consisted of less folded mucosa than that observed in the oesophagus of catfish. The epithelium was characterized by the presence of taste buds. In conclusion, the present work revealed some differences in the structure of catfish oesophagus and grass carp oesophagus. These differences are related to type of food and feeding habits of each species.

  8. Aphids and their parasitoids on the Canary grass, Phalaris canariensis in Malta (Hymenoptera, Braconidae, Aphidiinae)

    OpenAIRE

    Stankovic, Sasa; Stary, Petr; Mifsud, David

    2013-01-01

    Adialytus ambiguus and Diaeretiella rapae were reared from Rhopalosiphum padi on the Canary grass, Phalaris canariensis in Malta. The identity to species level of the Adialytus required confirmation via DNA analysis of the respective species group. Some ecosystem interrelationships derived from the determined food webs are discussed.

  9. Grass allometry and estimation of above-ground biomass in tropical alpine tussock grasslands

    NARCIS (Netherlands)

    Oliveras Menor, I.; Eynden, van der M.; Malhi, Y.; Cahuana, N.; Menor, C.; Zamora, F.; Haugaasen, T.

    2014-01-01

    The puna/páramo grasslands span across the highest altitudes of the tropical Andes, and their ecosystem dynamics are still poorly understood. In this study we examined the above-ground biomass and developed species specific and multispecies power-law allometric equations for four tussock grass speci

  10. Use of Biological Additives with Grass Containing Medium and High Levels of WSC for Effective Conservation and Aerobic Stability

    Directory of Open Access Journals (Sweden)

    Judit Peter Szucs

    2012-05-01

    Full Text Available The objective of the trials was to determine the effect of two silage inoculant strains Lactobacillus buchneri and Propionibacteria acidipropionici on grass containing medium and high levels of WSC for fermentation characteristics and aerobic stability of silages. The basic raw materials originated from second growth cut grasses from 2 different plots of the farm: 1st.grass components were a mixture of grass- and leguminous species, contained medium 1.5-3.0% WSC/FM. The 2nd grass components was mainly grass species; with high>3% WSC/FM content. We stored the filled micro (4.2 litre containers on ambient temperature. It was proven that both inoculant strains significantly decreased lactic acid content (P<0.01 and increased acetic acid content (P<0.001 of silages and significantly increased the aerobic stability as well. The best aerobic stability>240 hours was the Lactobacillus buchneri treated silages originated from medium WSC/FM grass. The main advantage of treatment of L. buchneri on grass compared to P. acidipropionici is the longer aerobic stability of silage (P<0.001.There was no significant differences among the microbiological profile neither of treated nor of control silages.

  11. First direct confirmation of grass carp spawning in a Great Lakes tributary

    Science.gov (United States)

    Embke, Holly S.; Kocovsky, Patrick M.; Richter, Catherine A.; Pritt, Jeremy J.; Christine M. Mayer,; Qian, Song

    2016-01-01

    Grass carp (Ctenopharyngodon idella), an invasive species of Asian carp, has been stocked for many decades in the United States for vegetation control. Adult individuals have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. In 2012, a commercial fisherman caught four juvenile diploid grass carp in the Sandusky River, a major tributary to Lake Erie. Otolith microchemistry and the capture location of these fish permitted the conclusion that they were most likely produced in the Sandusky River. Due to this finding, we sampled ichthyoplankton using paired bongo net tows and larval light traps during June–August of 2014 and 2015 to determine if grass carp are spawning in the Sandusky River. From the samples collected in 2015, we identified and staged eight eggs that were morphologically consistent with grass carp. Five eggs were confirmed as grass carp using quantitative Polymerase Chain Reaction for a grass carp-specific marker, while the remaining three were retained for future analysis. Our finding confirms that grass carp are naturally spawning in this Great Lakes tributary. All eggs were collected during high-flow events, either on the day of peak flow or 1–2 days following peak flow, supporting an earlier suggestion that high flow conditions favor grass carp spawning. The next principal goal is to identify the spawning and hatch location(s) for the Sandusky River. Predicting locations and conditions where grass carp spawning is most probable may aid targeted management efforts.

  12. Personal exposure to grass pollen: relating inhaled dose to background concentration

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Smith, Matt;

    2013-01-01

    . A 2003 World Health Organization report highlighted the need for an improved understanding of the relation between monitoring station data and actual exposure. Objective: To investigate the relation between grass pollen dose and background concentrations measured at a monitoring station, to assess...... the fidelity of monitoring station data as a qualitative proxy for dose, and to evaluate the ratio of dose rate to background concentration. Methods: Grass pollen dose data were collected in Aarhus, Denmark, in an area where grass pollen sources were prevalent, using Nasal Air Samplers. Sample collection...... of day when grass species likely to be present in the area are expected to flower. From 4 to 8 PM, dose rate and background concentration data were found to be strongly and significantly correlated (r(s) = 0.81). Averaged dose rate and background concentration data showed opposing temporal trends...

  13. Unique aspects of the grass cell wall

    Science.gov (United States)

    Grasses are amongst the most important crops worldwide, and the composition of their cell walls is critical for uses as food, feed, and energy crops. Grass cell walls differ dramatically from dicot cell walls in terms of the major structural polysaccharides present, how those polysaccharides are lin...

  14. A Walk in the "Tall, Tall Grass"

    Science.gov (United States)

    Kaatz, Kathryn

    2008-01-01

    This inquiry-based lesson was inspired by Denise Fleming's book entitled, "In the Tall, Tall Grass" (1991). The author used the book and a real study of prairie grasses to teach kindergartners how to make careful observations and record what they see. In addition, they learn how to "draw as scientists." Here the author describes her class's yearly…

  15. Foraminifera and the ecology of sea grass communities since the late Cretaceous

    Science.gov (United States)

    Hart, Malcolm; Smart, Christopher; Jagt, John

    2016-04-01

    Sea grasses are marine angiosperms (plants) that, in the late Cretaceous, migrated from the land into shallow-water marine environments. They represent a distinct, but fragile, marine habitat and sea grass meadows are often regarded as biodiversity hot-spots with a range of species (including fish, sea horses and cuttlefish) using them as nurseries for their young. Foraminifera are often found associated with sea grass meadows, with the associated taxa reflecting both the environment and palaeolatitude. In the tropics and sub-tropics, miliolid foraminifera dominate (e.g., Peneroplis spp.) as do large discoidal taxa such as Marginopora and Calcarina. In temperate to cool latitudes the assemblage changes to one dominated by smaller benthic taxa, including Elphidium spp. One taxon, Elphidium crispum, is geotropic and is often found - in the summer months - to crowd the fronds of the sea grass. In the Gulpen and Maastricht formations of the Maastricht area (The Netherlands and Belgium) sea grass fossils (both fronds and rhizomes) have been recorded in association with assemblages of both larger and smaller benthic foraminifera (Hart et al., 2016). Some of the large discoidal forms (e.g., Omphalocyclus and Orbitoides/Lepidorbitoides) and the distinctive Siderolites are associated with these sea grass fossils and are suggestive of the modern sea grass communities of sub-tropical areas. While earlier records were of relatively isolated sea grasses, in September/October 2015 surfaces with abundant sea grasses were found that are suggestive of complete 'meadows'. Preservation of some silicified rhizomes indicates that silicification must have been very rapid, before any degradation or compaction of the delicate tissues. The presence of sea grass fossils and their associated benthic foraminifera is indicative of a clear, shallow-water seaway, with a maximum depth of 15-20 m. The reported variations in sea level during the latest Cretaceous cannot, therefore, have been very

  16. Biomass Partitioning Following Defoliation of Annual and Perennial Mediterranean Grasses

    Directory of Open Access Journals (Sweden)

    No'am Seligman

    2002-01-01

    Full Text Available A two-year experiment was conducted in northeastern Israel to study the effects of various defoliation regimes on biomass partitioning between vegetative and reproductive structures in a perennial and an annual Mediterranean grass. Greater insight into the mechanisms regulating biomass partitioning after defoliation enables ecologists and rangeland managers to interpret and predict population and community dynamics in Mediterranean grasslands more efficiently. Two typical Mediterranean grasses, Triticum dicoccoides, an annual species, and Hordeum bulbosum, a perennial species, were grown in containers in the open. They were subjected to a series of defoliation treatments that comprised three clipping frequencies and three clipping heights in a full factorial combination. In addition, individuals of both species were sampled in the field, in paddocks that were grazed, and in a control exclosure that was closed to grazing during the growing season. The experiment was conducted over two growing seasons, one unusually dry and one unusually wet. The clipping treatments invariably caused a reduction in the amount of biomass partitioned to the reproductive organs, but had little effect on the vegetative components of the plants. Greater tillering following defoliation compensated, to a large degree, for the loss of photosynthetic biomass following defoliation. The effect of grazing on biomass partitioning was much lower than the effect of clipping. Under grazing, the investment in reproductive biomass was considerably higher than when the grasses were clipped. The results of this experiment help to elucidate the reasons for the persistence of these species and, especially, for the dominance of Hordeum bulbosum in many eastern Mediterranean grasslands.

  17. Satellite Phenology Observations Inform Peak Season of Allergenic Grass Pollen Aerobiology across Two Continents

    Science.gov (United States)

    Huete, A. R.; Devadas, R.; Davies, J.

    2015-12-01

    Pollen exposure and prevalence of allergenic diseases have increased in many parts of the world during the last 30 years, with exposure to aeroallergen grass pollen expected to intensify with climate change, raising increased concerns for allergic diseases. The primary contributing factors to higher allergenic plant species presence are thought to be climate change, land conversion, and biotic mixing of species. Conventional methods for monitoring airborne pollen are hampered by a lack of sampling sites and heavily rely on meteorology with less attention to land cover updates and monitoring of key allergenic species phenology stages. Satellite remote sensing offers an alternative method to overcome the restrictive coverage afforded by in situ pollen networks by virtue of its synoptic coverage and repeatability of measurements that enable timely updates of land cover and land use information and monitoring landscape dynamics and interactions with human activity and climate. In this study, we assessed the potential of satellite observations of urban/peri-urban environments to directly inform landscape conditions conducive to pollen emissions. We found satellite measurements of grass cover phenological evolution to be highly correlated with in situ aerobiological grass pollen concentrations in five urban centres located across two hemispheres (Australia and France). Satellite greenness data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were found to be strongly synchronous with grass pollen aerobiology in both temperate grass dominated sites (France and Melbourne), as well as in Sydney, where multiple pollen peaks coincided with the presence of subtropical grasses. Employing general additive models (GAM), the satellite phenology data provided strong predictive capabilities to inform airborne pollen levels and forecast periods of grass pollen emissions at all five sites. Satellite phenology offer promising opportunities of improving public health risk

  18. Socioeconomic Study of Grasses and Legumes in Baria and Godhra Forest Division, Gujarat

    Directory of Open Access Journals (Sweden)

    Dhara J. GANDHI

    2011-08-01

    Full Text Available Gujarat has rich traditional knowledge associated with biodiversity. The cultural diversity in the Indian society reflects close relationship between the existence of human life and nature including all other living creatures and non-living creatures. The present paper deals with the traditional knowledge of villagers in 10 villages nearby the grasslands in Panchmahal and Dahod districts of Gujarat, India, regarding the multipurpose use of grasses and associated legumes prevailing in these grasslands. A survey with the help of questionnaire was conducted to analyze the socioeconomic status. 69 grass species and 34 legumes could be identified growing in these grasslands of which 92 were used for livestocks. Among these grasses the most preferred grass species were Dichanthium annulatum and Sehima nervosum because of its high palatability. Three grasses and 8 legume species were used for food and medicine. The study emphasizes the use of plant wealth to human needs of the regions and assist in appraisal of various anthropogenic interventions accountable for loss of prevailing biodiversity of the region.

  19. Photosynthesis of C3, C3-C4, and C4 grasses at glacial CO2.

    Science.gov (United States)

    Pinto, Harshini; Sharwood, Robert E; Tissue, David T; Ghannoum, Oula

    2014-07-01

    Most physiology comparisons of C3 and C4 plants are made under current or elevated concentrations of atmospheric CO2 which do not reflect the low CO2 environment under which C4 photosynthesis has evolved. Accordingly, photosynthetic nitrogen (PNUE) and water (PWUE) use efficiency, and the activity of the photosynthetic carboxylases [Rubisco and phosphoenolpyruvate carboxylase (PEPC)] and decarboxylases [NADP-malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PEP-CK)] were compared in eight C4 grasses with NAD-ME, PCK, and NADP-ME subtypes, one C3 grass, and one C3-C4 grass grown under ambient (400 μl l(-1)) and glacial (180 μl l(-1)) CO2. Glacial CO2 caused a smaller reduction of photosynthesis and a greater increase of stomatal conductance in C4 relative to C3 and C3-C4 species. Panicum bisulcatum (C3) acclimated to glacial [CO2] by doubling Rubisco activity, while Rubisco was unchanged in Panicum milioides (C3-C4), possibly due to its high leaf N and Rubisco contents. Glacial CO2 up-regulated Rubisco and PEPC activities in concert for several C4 grasses, while NADP-ME and PEP-CK activities were unchanged, reflecting the high control exerted by the carboxylases relative to the decarboxylases on the efficiency of C4 metabolism. Despite having larger stomatal conductance at glacial CO2, C4 species maintained greater PWUE and PNUE relative to C3-C4 and C3 species due to higher photosynthetic rates. Relative to other C4 subtypes, NAD-ME and PEP-CK grasses had the highest PWUE and PNUE, respectively; relative to C3, the C3-C4 grass had higher PWUE and similar PNUE at glacial CO2. Biomass accumulation was reduced by glacial CO2 in the C3 grass relative to the C3-C4 grass, while biomass was less reduced in NAD-ME grasses compared with NADP-ME and PCK grasses. Under glacial CO2, high resource use efficiency offers a key evolutionary advantage for the transition from C3 to C4 photosynthesis in water- and nutrient-limited environments.

  20. Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2014-06-01

    Full Text Available The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass - Brachiaria ruziziensis in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation with several species under no-till for six years. An application rate of no P or 240 kg ha-1 of P2O5 had been applied as triple superphosphate or as Arad rock phosphate. In April 2009, once more 0.0 or 80.0 kg ha-1 of P2O5 was applied to the same plots when Congo grass was planted. In November 2009, after Congo grass desiccation, soil samples were taken from the 0-5 and 5-10 cm depth layer and soil P was fractionated. Soil-available P increased to the depth of 10 cm through growing Congo grass when P fertilizers were applied. The C:P ratio was also increased by the cover crop. Congo grass cultivation increased P content in the soil humic fraction to the depth of 10 cm. Congo grass increases soil P availability by preventing fertilizer from being adsorbed and by increasing soil organic P.

  1. X meeting utenti GRASS e GFOSS

    Directory of Open Access Journals (Sweden)

    Francesco Marucci

    2009-03-01

    Full Text Available 10th meeting of GRASS & GFOSS usersThe 10th Italian Congress of GRASS GIS and Geospatial Free and Open Source Software (GFOSS was held on the26 and 27 Feb in Cagliari. Highlights included updates on major GFOSS projects (GRASS, QGIS, the presentation of new projects (SpatiaLite and the public release of a free 3D visualization application suitable for distribution over the internet (RATMAN. Many users and developers connected to forge new business relationships and share new ideas.

  2. X meeting utenti GRASS e GFOSS

    OpenAIRE

    Francesco Marucci; Luca Dellucchi; Paolo Cavallini

    2009-01-01

    10th meeting of GRASS & GFOSS usersThe 10th Italian Congress of GRASS GIS and Geospatial Free and Open Source Software (GFOSS) was held on the26 and 27 Feb in Cagliari. Highlights included updates on major GFOSS projects (GRASS, QGIS), the presentation of new projects (SpatiaLite) and the public release of a free 3D visualization application suitable for distribution over the internet (RATMAN). Many users and developers connected to forge new business relationships and share new ideas.

  3. Effects of feeding salt-tolerant grasses on the reproductive efficiency of dwarf goats

    International Nuclear Information System (INIS)

    Salinity of soil and groundwater is a major agricultural problem facing several countries. Numerous approaches have been made to alleviate this situation. A biological approach has been developed at our Institute whereby salt-tolerant plants that are more suited to the environment have been grown rather than reclamation of land for conventional crops. Kallar grass (Leptochloa fusca) has been grown on such lands using brackish water for irrigation, thus producing large amounts of biomass. Since this biomass is not usually used as forage it was necessary to evaluate its effects on the growth and reproduction of farm animals. Buffalo, cows and goats are important for providing milk and meat in Pakistan. Goats are more important in arid and semi-arid areas. Dwarf goats were selected for the study because of easier handling, a shorter maturity period, better breeding, etc. One group of goats was contained and fed only Kallar grass throughout the year. (This grass is green in summer and, although it is a perennial, it dries in winter). Another group was allowed to free graze an area where, in addition to Kallar grass, some other wild species were also available. The effects of this forage were evaluated by recording the weight of the animals, pregnancies, lamb survival and hormone levels. It was found that when dry grass was the only source of nutrition the animals lost weight and reproduction was also affected; even though conception did take place lactation was reduced, the animals had difficulty in delivery and the lambs were born weak and did not survive. The progesterone and oestradiol levels and patterns were normal. The study concludes that dwarf goats can survive even when fed dry, low protein grass and that their body weight increases when the grass is green. They can, therefore, be raised on Kallar grass if kept for meat purposes; however, if they are to be maintained for breeding some supplementary fodder is desirable. Poor nutrition did not affect the hormone

  4. Does crotalaria (Crotalaria breviflora or pumpkin (Cucurbita moschata inter-row cultivation in restoration plantings control invasive grasses?

    Directory of Open Access Journals (Sweden)

    Ricardo Gomes César

    2013-08-01

    Full Text Available Alternative methods to control invasive fodder grasses are necessary to reduce the use of herbicides in forest restoration, which has been carried out primarily in riparian zones. We sought to investigate if inter-row cultivation of crotalaria (Crotalaria breviflora DC or pumpkin (Cucurbita moschata Duschene ex. Poir with native tree species is an efficient strategy to control invasive fodder grasses in restoration plantings. We tested five treatments in a randomized block design, namely (1 control of brachiaria grass (Urochloa decumbens (Stapf. Webster with glyphosate in the implementation and post-planting grass control of the reforestation, (2 and 3 glyphosate use in the implementation and inter-row sowing of crotalaria (2 or pumpkin (3, and control of brachiaria by mowing in the post-planting phase, (4 and 5 mowing in the implementation and inter-row sowing of crotalaria (4 or pumpkin (5, and control of brachiaria by mowing in the post-planting phase. Post-planting grass control was carried out four and nine months after tree seedling planting. Throughout 13 months, we evaluated the percentage of ground cover by brachiaria grass, pumpkin production, and native tree seedling mortality, height and crown cover. The exclusive use of glyphosate, without inter-row sowing of pumpkin or crotalaria showed the most favorable results for controlling brachiaria grass and, consequently, for tree seedling development. Hence, inter-row cultivation of green manure or short-lived crop species is not enough to control invasive grasses in restoration plantings, and complementary weeding is necessary to reduce the highly competitive potential of C4 grasses for supporting native species seedlings growth.

  5. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    Energy Technology Data Exchange (ETDEWEB)

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  6. Capim - gordura (Melinis minutiflora P. Beauv., uma gramínea exótica que compromete a recuperação de áreas degradadas em unidades de conservação Molasses grass (Melinis minutiflora P. Beauv., an exotic species compromising the recuperation of degraded areas in conservation units

    Directory of Open Access Journals (Sweden)

    Carlos Romero Martins

    2004-10-01

    Full Text Available O capim-gordura, Melinis minutiflora, é uma gramínea de origem africana que invade áreas degradadas da região do Cerrado em detrimento das espécies nativas. A interferência do capim-gordura no processo de sucessão e o efeito da queimada controlada sobre essa gramínea foram estudados em uma cascalheira localizada no Parque Nacional de Brasília. O estudo foi realizado numa área experimental em que, em 1993, havia sido implantado um experimento para avaliar o estabelecimento de gramíneas nativas pela técnica do "coquetel de sementes". Mesmo não estando entre as espécies semeadas, o capim-gordura estabeleceu-se nas parcelas experimentais, onde se incorporou torta de mamona ou turfa. Metade das parcelas que apresentaram os melhores índices de cobertura do solo foi queimada no final da estação seca, em setembro de 1998. Em maio de 1999, oito meses após a queimada verificou-se redução da cobertura do substrato superior a 50%, em comparação com a cobertura antes da queimada. Nos anos subseqüentes, o índice de cobertura do substrato voltou a crescer, atingindo, em maio de 2001, os valores observados antes da queimada. Durante esse período, notou-se, nas parcelas queimadas e nãoqueimadas, aumento na contribuição do capim-gordura para o índice total de cobertura do solo, em detrimento das espécies nativas. O uso do fogo não foi eficaz no controle dessa invasora. Assim, em programas de recuperação de áreas degradadas em áreas protegidas é necessário controlar as espécies invasoras exóticas para permitir o estabelecimento de um maior número de espécies nativas do Cerrado.Melinis minutiflora is an African grass that invades degraded areas in the cerrado endangering native species. The effects of this invasion and of burning on Melinis minutiflora propagation were investigated in a gravel-mining pit, within the National Park of Brasilia. This study was conducted in an area where an experimental field was set up in 1993

  7. A grass molecular identification system for forensic botany: a critical evaluation of the strengths and limitations.

    Science.gov (United States)

    Ward, Jodie; Gilmore, Simon R; Robertson, James; Peakall, Rod

    2009-11-01

    Plant material is frequently encountered in criminal investigations but often overlooked as potential evidence. We designed a DNA-based molecular identification system for 100 Australian grasses that consisted of a series of polymerase chain reaction assays that enabled the progressive identification of grasses to different taxonomic levels. The identification system was based on DNA sequence variation at four chloroplast and two mitochondrial loci. Seventeen informative indels and 68 single-nucleotide polymorphisms were utilized as molecular markers for subfamily to species-level identification. To identify an unknown sample to subfamily level required a minimum of four markers or nine markers for species identification. The accuracy of the system was confirmed by blind tests. We have demonstrated "proof of concept" of a molecular identification system for trace botanical samples. Our evaluation suggests that the adoption of a system that combines this approach with DNA sequencing could assist the morphological identification of grasses found as forensic evidence. PMID:19818109

  8. A review on biomass production from C4 grasses: yield and quality for end-use.

    Science.gov (United States)

    Tubeileh, Ashraf; Rennie, Timothy J; Goss, Michael J

    2016-06-01

    With a dry biomass production exceeding 40Mgha(-1) in many environments, Miscanthus spp. is the most productive perennial C4 grass species thanks to five advantages over North American prairie tallgrasses. However, miscanthus has a slower nutrient remobilization system, resulting in higher nutrient concentrations at harvest. Perennial C4 grasses benefit from soil microbial associations, reducing their nutrient needs. For combustion purposes, grasses with low moisture content, high lignin and low nutrients are desired. For ethanol, preferred feedstock will have lower lignin, higher sugars, starch, or cellulose/hemicellulose depending on the conversion method. Species with high stem-to-leaf ratio provide better biofuel conversion efficiency and quality. Recently-developed transgenic switchgrass lines have much higher ethanol yields and lower transformation costs. Further selection and breeding are needed to optimize biomass quality and nutrient cycling. PMID:27258573

  9. Data on litter quality of host grass plants with and without fungal endophytes

    OpenAIRE

    Gundel, P.E.; Helander, M.; Garibaldi, L.A.; Vázquez-de-Aldana, B.R.; Zabalgogeazcoa, I.; Saikkonen, K.

    2016-01-01

    Certain Pooideae species form persistent symbiosis with fungal endophytes of Epichloë genus. Although endophytes are known to impact the ecology and evolution of host species, their effects on parameters related with quality of plant biomass has been elusive. This article provides information about parameters related with the quality of plant litter biomass of two important grass species (Schedonorus phoenix and Schedonorus pratensis) affected by the symbiosis with fungal endophytes (Epichloë...

  10. Edge effect on carabid assemblages along forest-grass transects

    OpenAIRE

    Magura, T.; B. Tóthmérész; T. Molnár

    2001-01-01

    During 1997 and 1998, we have tested the edge-effect for carabids along oak-hornbeam forest-grass transects using pitfall traps in Hungary. Our hypothesis was that the diversity of carabids will be higher in the forest edge than in the forest interior. We also focused on the characteristic species of the habitats along the transects and the relationships between their distribution and the biotic and abiotic factors.

    Our results proved that there was a significant edge eff...

  11. Phytochemical changes in leaves of subtropical grasses and fynbos shrubs at elevated atmospheric CO 2 concentrations

    Science.gov (United States)

    Hattas, D.; Stock, W. D.; Mabusela, W. T.; Green, I. R.

    2005-07-01

    The effects of elevated atmospheric CO 2 concentrations on plant polyphenolic, tannin, nitrogen, phosphorus and total nonstructural carbohydrate concentrations were investigated in leaves of subtropical grass and fynbos shrub species. The hypothesis tested was that carbon-based secondary compounds would increase when carbon gain is in excess of growth requirements. This premise was tested in two ecosystems involving plants with different photosynthetic mechanisms and growth strategies. The first ecosystem comprised grasses from a C 4-dominated, subtropical grassland, where three plots were subjected to three different free air CO 2 enrichment treatments, i.e., elevated (600 to 800 μmol mol -1), intermediate (400 μmol mol -1) and ambient atmospheric CO 2. One of the seven grass species, Alloteropsis semialata, had a C 3 photosynthetic pathway while the other grasses were all C 4. The second ecosystem was simulated in a microcosm experiment where three fynbos species were grown in open-top chambers at ambient and 700 μmol mol -1 atmospheric CO 2 in low nutrient acid sands typical of south western coastal and mountain fynbos ecosystems. Results showed that polyphenolics and tannins did not increase in the grass species under elevated CO 2 and only in Leucadendron laureolum among the fynbos species. Similarly, foliar nitrogen content of grasses was largely unaffected by elevated CO 2, and among the fynbos species, only L. laureolum and Leucadendron xanthoconus showed changes in foliar nitrogen content under elevated CO 2, but these were of different magnitude. The overall decrease in nitrogen and phosphorus and consequent increase in C:N and C:P ratio in both ecosystems, along with the increase in polyphenolics and tannins in L. laureolum in the fynbos ecosystem, may negatively affect forage quality and decomposition rates. It is concluded that fast growing grasses do not experience sink limitation and invest extra carbon into growth rather than polyphenolics and

  12. Pampas Grass - Orange Co. [ds351

    Data.gov (United States)

    California Department of Resources — This dataset provides the known distribution of pampas grass (Cortaderia selloana) in southern Orange County. The surveys were conducted from May to June, 2007 and...

  13. Karl Konrad Grass jumalainimeste uurijana / Alar Laats

    Index Scriptorium Estoniae

    Laats, Alar

    2006-01-01

    Karl Konrad Grass oli 19. sajandil Dorpati keiserliku ülikooli usuteaduskonna Uue Testamendi õppejõud, kes tegeles hobi korras idakristluse (vene sektid) uurimisega. Tema peateoseks on uurimus "Die russischen Sekten". Ettekanne konverentsil 15.-16. aprill 2005. a.

  14. Distinguishing grass from ground using LiDAR: Techniques and applications

    Science.gov (United States)

    Pelletier, J. D.; Swetnam, T.; Papuga, S. A.; Nelson, K.; Brooks, P. D.; Harpold, A. A.; Chorover, J.

    2011-12-01

    Standard protocols exist for extracting bare-earth Digital Elevation Models (DEMs) from LiDAR point clouds that include trees and other large woody vegetation. Grasses and other herbaceous plants can also obscure the ground surface, yet methods for optimally distinguishing grass from ground to generate accurate LiDAR-based raster products for geomorphic and ecological applications are still under development. Developing such methods is important because LiDAR-based difference products (e.g. snow thickness) require accurate representations of the ground surface and because raster data for grass height and density have important applications in ecology. In this study, we developed and tested methods for constructing optimal bare-earth and grass height raster layers from LiDAR point clouds and compared the results to high-quality field-based measurements of grass height, density, and species type for nearly 1000 precisely geo-referenced locations collected during the acquisition of a >200 km^2 airborne LiDAR flight of the Valles Caldera National Preserve (New Mexico). In cases of partially bare ground (where the skewness of return heights above a plane fit to the lowest first returns is sufficiently large), a planar fit to the lowest first returns provides a good method of producing an accurate bare-earth DEM and the statistics of the first returns above that planar fit provide good estimates of the mean and variance of grass height. In areas of relatively thick grass cover, however, a fit to the lowest first returns yields a bare-earth DEM that may be a meter or more above the actual ground surface. Here we propose a method to solve this problem using field-measured correlations among the mean, variance, and skewness of grass heights. In this method, the variance and skewness of the differences between LiDAR first returns and a 10m^2 planar fit to the lowest first returns is used, together with field-based correlations of grass height statistics, to estimate the mean

  15. Genetic compatibility determines endophyte-grass combinations.

    Directory of Open Access Journals (Sweden)

    Kari Saikkonen

    Full Text Available Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1 and F(2 generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1 genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2 these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars.

  16. Madagascar's grasses and grasslands: anthropogenic or natural?

    Science.gov (United States)

    Vorontsova, Maria S; Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W Derek; Ficinski, Paweł; Savva, George M; Nanjarisoa, Olinirina P; Razanatsoa, Jacqueline; Randriatsara, Fetra O; Kimeu, John M; Luke, W R Quentin; Kayombo, Canisius; Linder, H Peter

    2016-01-27

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics.

  17. Genetic compatibility determines endophyte-grass combinations.

    Science.gov (United States)

    Saikkonen, Kari; Wäli, Piippa R; Helander, Marjo

    2010-01-01

    Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds) transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1) and F(2) generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1) genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2) these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars. PMID:20614034

  18. Madagascar's grasses and grasslands: anthropogenic or natural?

    Science.gov (United States)

    Vorontsova, Maria S; Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W Derek; Ficinski, Paweł; Savva, George M; Nanjarisoa, Olinirina P; Razanatsoa, Jacqueline; Randriatsara, Fetra O; Kimeu, John M; Luke, W R Quentin; Kayombo, Canisius; Linder, H Peter

    2016-01-27

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  19. Microsatellite diversity of the agriculturally important alpine grass Poa alpina in relation to land use and natural environment

    OpenAIRE

    Rudmann-Maurer, K; Weyand, A; Fischer, M.; STÖCKLIN, J.

    2007-01-01

    Background and Aims: The Alpine Meadow Grass Poa alpina is common in subalpine and alpine natural sites and agriculturally used land, where it is an important fodder grass. Natural factors and human land use are supposed to have been shaping its genetic diversity for hundreds of years. The species comprises sexually and vegetatively reproducing plants. The aim of this study was to investigate the effects of agricultural land use, environmental factors and the mode of reproduction on the distr...

  20. Insular organization of gene space in grass genomes.

    Directory of Open Access Journals (Sweden)

    Andrea Gottlieb

    Full Text Available Wheat and maize genes were hypothesized to be clustered into islands but the hypothesis was not statistically tested. The hypothesis is statistically tested here in four grass species differing in genome size, Brachypodium distachyon, Oryza sativa, Sorghum bicolor, and Aegilops tauschii. Density functions obtained under a model where gene locations follow a homogeneous Poisson process and thus are not clustered are compared with a model-free situation quantified through a non-parametric density estimate. A simple homogeneous Poisson model for gene locations is not rejected for the small O. sativa and B. distachyon genomes, indicating that genes are distributed largely uniformly in those species, but is rejected for the larger S. bicolor and Ae. tauschii genomes, providing evidence for clustering of genes into islands. It is proposed to call the gene islands "gene insulae" to distinguish them from other types of gene clustering that have been proposed. An average S. bicolor and Ae. tauschii insula is estimated to contain 3.7 and 3.9 genes with an average intergenic distance within an insula of 2.1 and 16.5 kb, respectively. Inter-insular distances are greater than 8 and 81 kb and average 15.1 and 205 kb, in S. bicolor and Ae. tauschii, respectively. A greater gene density observed in the distal regions of the Ae. tauschii chromosomes is shown to be primarily caused by shortening of inter-insular distances. The comparison of the four grass genomes suggests that gene locations are largely a function of a homogeneous Poisson process in small genomes. Nonrandom insertions of LTR retroelements during genome expansion creates gene insulae, which become less dense and further apart with the increase in genome size. High concordance in relative lengths of orthologous intergenic distances among the investigated genomes including the maize genome suggests functional constraints on gene distribution in the grass genomes.

  1. Germination, survival, and growth of grass and forb seedlings: effects of soil moisture variability

    Science.gov (United States)

    Seed germination and seedling growth, survivorship, and final biomass and their responses to varying numbers of days between watering were studied in two grass and six forb species native to the U.S. Central Plains grasslands. Our object was to assess the potential role of germination and seedling g...

  2. Continuous growth of the giant grass Zizaniopsis bonariensis in subtropical wetlands

    NARCIS (Netherlands)

    Finkler Ferreira, T.; Nes, van E.H.; Motta Marques, da D.

    2009-01-01

    1. Zizaniopsis bonariensis (giant grass) is an emergent macrophyte species endemic to subtropical wetlands in Brazil, Argentina, Paraguay and Uruguay. In this study, we show the effects of its continuous clonal reproduction and its 'phalanx' growth strategy in the Taim Wetland (southern Brazil). 2.

  3. Analysis of the soil food web structure under grass and grass clover

    NARCIS (Netherlands)

    Eekeren, van N.J.M.; Smeding, F.W.; Vries, de F.T.; Bloem, J.

    2006-01-01

    The below ground biodiversity of soil organisms plays an important role in the functioning of the the soil ecosystem, and consequently the above ground plant production. The objective of this study is to investigate the effect of grass or grass-clover in combination with fertilisation on the soil fo

  4. Influência do intervalo entre cortes sobre a produção de biomassa de duas espécies de capim limão Influence of the interval between cuts on biomass yield of two lemon grass species

    Directory of Open Access Journals (Sweden)

    André May

    2008-09-01

    Full Text Available Foi estudada a influência do intervalo entre cortes na produção de massa seca da parte aérea de duas espécies de capim limão. O experimento foi realizado no Instituto Agronômico, em Campinas-SP, 04 de junho/05 a 28 de agosto/06. O delineamento experimental utilizado foi em blocos ao acaso, com três repetições, com os tratamentos em esquema fatorial 2 x 4, sendo duas espécies (C. citratus e C. flexuosus e quatro intervalos entre cortes (40; 60; 80 e 100 dias. Para C. flexuosus, maiores intervalos entre cortes proporcionaram maior massa seca acumulada ao longo do ciclo de cultivo, partindo de 329,04 para 704,16 g planta-1 de massa seca acumulada da parte aérea, para intervalos entre cortes de 40 e 100 dias, respectivamente. A espécie C. citratus apresentou resposta linear decrescente da massa seca acumulada da parte aérea quanto maior o intervalo entre cortes utilizado, produzindo 238,68 g planta-1 utilizando intervalo entre cortes de 40 dias.The aim of this study was to analyze the influence of the interval between cuts on the dry mass yield of the aerial part of two lemon grass species. The experiment was conducted at Agronomical Institute (IAC, in Campinas - SP, from June 4th, 2005 through August 28th, 2006. The experiment was carried out in a completely randomized block design, with three replications, and the treatments in a 2 x 4 factorial design, corresponding two species (C. citratus and C. flexuosus and four intervals between cuts (40; 60; 80 and 100 days. For C. flexuosus, longer intervals between cuts generated more dry mass accumulated throughout the cultivation cycle, beginning on 329,04 to 704,16 g plant-1 of accumulated dry mass of the aerial part, for intervals between cuts of 40 and 100 days, respectively. The C. citratus species showed a decrease in its linear response for the accumulated dry mass of the aerial part the longer the interval between cuts was, yielding 238,68 g plant-1 for a 40 day interval between

  5. Persistence of Overseeded Cool-Season Grasses in Bermudagrass Turf

    Directory of Open Access Journals (Sweden)

    Thomas Serensits

    2011-01-01

    Full Text Available Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally persisted the most one year after seeding, either because of summer survival of plants or because of new germination the following fall. Plant counts one year after seeding were greater in the higher seeding rate treatment compared to the lower seeding treatment rate of perennial ryegrass, suggesting new germination had occurred. Plant counts one year after seeding plots with intermediate ryegrass or Italian ryegrass were attributed primarily to latent germination and not summer survival. Applications of foramsulfuron generally did not prevent overseeded species stand one year after seeding, supporting the conclusion of new germination. Although quality is less with intermediate ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year later.

  6. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence.

    Directory of Open Access Journals (Sweden)

    Michael G Mazzacavallo

    Full Text Available Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D. The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0-20 cm and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20-90 cm, the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone.

  7. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence.

    Science.gov (United States)

    Mazzacavallo, Michael G; Kulmatiski, Andrew

    2015-01-01

    Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D). The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0-20 cm) and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20-90 cm), the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone. PMID:26633177

  8. Divergent evolutionary histories of C4 grasses shape global grassland ecology

    Science.gov (United States)

    Lehmann, C.; Griffith, D.; Osborne, C.

    2014-12-01

    C4 photosynthesis has evolved in more than 23 independent lineages of grasses as an adaptation to hot, sunny conditions. Geological records demonstrate that C4 grasses abruptly became ecologically dominant during the late Cenozoic across the tropical and temperate regions, transforming the Earth System and facilitating major faunal and floral radiations. However, although each C4 grass lineage originated and specialised in different environments, the importance of these divergent evolutionary histories for global ecology remains largely unknown. Here, we address this problem by compiling the first global map of grassy biomes based entirely upon ground-based vegetation surveys of dominant species. Our analysis shows that grasses dominate the ground layer across 40% of the vegetated land surface, with C4 grasses accounting for 60% of this area, and grassy biomes occurring under almost all climatic conditions. More than 98% of C3 grassy vegetation is dominated by the cold tolerant Pooideae lineage, which is replaced by C4 lineages at mean annual temperatures exceeding 15oC. The world's C4 grassy vegetation is largely dominated by only four of the 23 independent C4 grass lineages, and these segregate strongly along global environmental gradients and across continents. The Chloridoideae lineage is globally important in dominating semi-arid environments with a long fire return interval. In contrast, although the Andropogoneae lineage dominates extremely wet regions with frequent fire in the Paleotropics and North America, the same niche space is dominated by Paspaleae in South America. Sorting of lineages along precipitation and fire gradients is strongly predicted by plant height. Our results demonstrate that the divergent histories of independent C4 grass lineages have constrained the assembly and functional traits of grassy biomes, with important implications for understanding how biome boundaries may shift in past and future environments.

  9. Review of the integrated process for the production of grass biomethane.

    Science.gov (United States)

    Nizami, Abdul-Sattar; Korres, Nicholas E; Murphy, Jerry D

    2009-11-15

    Production of grass biomethane is an integrated process which involves numerous stages with numerous permutations. The grass grown can be of numerous species, and it can involve numerous cuts. The lignocellulosic content of grass increases with maturity of grass; the first cut offers more methane potential than the later cuts. Water-soluble carbohydrates (WSC) are higher (and as such methane potential is higher) for grass cut in the afternoon as opposed to that cut in the morning. The method of ensiling has a significant effect on the dry solids content of the grass silage. Pit or clamp silage in southern Germany and Austria has a solids content of about 40%; warm dry summers allow wilting of the grass before ensiling. In temperate oceanic climates like Ireland, pit silage has a solids content of about 21% while bale silage has a solids content of 32%. Biogas production is related to mass of volatile solids rather than mass of silage; typically one ton of volatile solid produces 300 m(3) of methane. The dry solids content of the silage has a significant impact on the biodigester configuration. Silage with a high solids content would lend itself to a two-stage process; a leach bed where volatile solids are converted to a leachate high in chemical oxygen demand (COD), followed by an upflow anaerobic sludge blanket where the COD can be converted efficiently to CH(4). Alternative configurations include wet continuous processes such as the ubiquitous continuously stirred tank reactor; this necessitates significant dilution of the feedstock to effect a solids content of 12%. Various pretreatment methods may be employed especially if the hydrolytic step is separated from the methanogenic step. Size reduction, thermal, and enzymatic methodologies are used. Good digester design is to seek to emulate the cow, thus rumen fluid offers great potential for hydrolysis.

  10. Evolution of centromeric retrotransposons in grasses.

    Science.gov (United States)

    Sharma, Anupma; Presting, Gernot G

    2014-06-01

    Centromeric retrotransposons (CRs) constitute a family of plant retroelements, some of which have the ability to target their insertion almost exclusively to the functional centromeres. Our exhaustive analysis of CR family members in four grass genomes revealed not only horizontal transfer (HT) of CR elements between the oryzoid and panicoid grass lineages but also their subsequent recombination with endogenous elements that in some cases created prolific recombinants in foxtail millet and sorghum. HT events are easily identifiable only in cases where host genome divergence significantly predates HT, thus documented HT events likely represent only a fraction of the total. If the more difficult to detect ancient HT events occurred at frequencies similar to those observable in present day grasses, the extant long terminal repeat retrotransposons represent the mosaic products of HT and recombination that are optimized for retrotransposition in their host genomes. This complicates not only phylogenetic analysis but also the establishment of a meaningful retrotransposon nomenclature, which we have nevertheless attempted to implement here. In contrast to the plant-centric naming convention used currently for CR elements, we classify elements primarily based on their phylogenetic relationships regardless of host plant, using the exhaustively studied maize elements assigned to six different subfamilies as a standard. The CR2 subfamily is the most widely distributed of the six CR subfamilies discovered in grass genomes to date and thus the most likely to play a functional role at grass centromeres. PMID:24814286

  11. Southern Florida's River of Grass

    Science.gov (United States)

    2002-01-01

    Florida's Everglades is a region of broad, slow-moving sheets of water flowing southward over low-lying areas from Lake Okeechobeeto the Gulf of Mexico. In places this remarkable 'river of grass' is 80 kilometers wide. These images from the Multi-angle Imaging SpectroRadiometer show the Everglades region on January 16, 2002. Each image covers an area measuring 191 kilometers x 205 kilometers. The data were captured during Terra orbit 11072.On the left is a natural color view acquired by MISR's nadir camera. A portion of Lake Okeechobee is visible at the top, to the right of image center. South of the lake, whose name derives from the Seminole word for 'big water,' an extensive region of farmland known as the Everglades Agricultural Area is recognizable by its many clustered squares. Over half of the sugar produced in United States is grown here. Urban areas along the east coast and in the northern part of the image extend to the boundaries of Big Cypress Swamp, situated north of Everglades National Park.The image on the right combines red-band data from the 46-degree backward, nadir and 46-degree forward-viewing camera angles to create a red, green, blue false-color composite. One of the interesting uses of the composite image is for detecting surface water. Wet surfaces appear blue in this rendition because sun glitter produces a greater signal at the forward camera's view angle. Wetlands visible in these images include a series of shallow impoundments called Water Conservation Areas which were built to speed water flow through the Everglades in times of drought. In parts of the Everglades, these levees and extensive systems such as the Miami and Tamiami Canals have altered the natural cycles of water flow. For example, the water volume of the Shark River Slough, a natural wetland which feeds Everglades National Park, is influenced by the Tamiami Canal. The unique and intrinsic value of the Everglades is now widely recognized, and efforts to restore the natural

  12. Characterisation of a Giant Lemon Grass Acclimatised in the Congo-Brazzaville

    Directory of Open Access Journals (Sweden)

    Loumouamou Aubin Nestor

    2010-11-01

    Full Text Available The aim of this study to investigate the essential oil of the giant variety of lemon grass (Poaceae obtained from farmers in Congo-Kinshasa and tested in Congo-Brazzaville. Chemical analysis, by GC and GCMS, of the essential oil from different parts of the plant, extracted at different stages of growth, revealed the very high stability of the citral chemotype (>80%; giving it the status of interesting species for the production of citral oil. However, it could not be identified to any of the oil-yielding grasses already described in the literature. Like Cymbopogon citratus (DC Stapf it produces an essential oil containing more than 80% citral, but displays morphological characteristics of vigorous grasses. The botanical description of the plant and the chemical composition of its oil identify it to Cymbopogon densiflorus (Steud Stapf.

  13. Automated conserved noncoding sequence (CNS discovery reveals differences in gene content and promoter evolution among grasses

    Directory of Open Access Journals (Sweden)

    Gina eTurco

    2013-07-01

    Full Text Available Conserved noncoding sequences (CNS are islands of noncoding sequence that, like protein coding exons, show less divergence in sequence between related species than functionless DNA. Several of CNSs have been demonstrated experimentally to function as cis-regulatory regions. However, the specific functions of most CNSs remain unknown. Previous searchers for CNS in plants have either anchored on exons and only identified nearby sequences or required years of painstaking manual annotation. Here we present an open source tool that can accurately identify CNSs between any two related species with sequenced genomes, including both those immediately adjacent to exons and distal sequences separated by >12 KB of noncoding sequence. We have used this tool to characterize new motifs, associate CNSs with additional functions and identify previously undetected genes encoding RNA and protein in the genomes of five grass species. We provide a list of 15,363 orthologous CNSs conserved across all grasses tested. We were also able to identify regulatory sequences present in the common ancestor of grasses that have been lost in one or more extant grass lineages. Lists of orthologous gene pairs and associated CNSs are provided for reference inbred lines of arabidopsis, Japonica rice, foxtail millet, sorghum, brachypodium and maize.

  14. Adaptation and detoxification mechanisms of Vetiver grass (Chrysopogon zizanioides) growing on gold mine tailings.

    Science.gov (United States)

    Melato, F A; Mokgalaka, N S; McCrindle, R I

    2016-01-01

    Vetiver grass (Chrysopogon zizanioides) was investigated for its potential use in the rehabilitation of gold mine tailings, its ability to extract and accumulate toxic metals from the tailings and its metal tolerant strategies. Vetiver grass was grown on gold mine tailings soil, in a hothouse, and monitored for sixteen weeks. The mine tailings were highly acidic and had high electrical conductivity. Vetiver grass was able to grow and adapt well on gold mine tailings. The results showed that Vetiver grass accumulated large amounts of metals in the roots and restricted their translocation to the shoots. This was confirmed by the bioconcentration factor of Zn, Cu, and Ni of >1 and the translocation factor of <1 for all the metals. This study revealed the defense mechanisms employed by Vetiver grass against metal stress that include: chelation of toxic metals by phenolics, glutathione S-tranferase, and low molecular weight thiols; sequestration and accumulation of metals within the cell wall that was revealed by the scanning electron microscopy that showed closure of stomata and thickened cell wall and was confirmed by high content of cell wall bound phenolics. Metal induced reactive oxygen species are reduced or eliminated by catalase, superoxide dismutase and peroxidase dismutase. PMID:26588814

  15. Forage mass and stocking rate of elephant grass pastures managed under agroecological and conventional systems

    Directory of Open Access Journals (Sweden)

    Clair Jorge Olivo

    2014-06-01

    Full Text Available The objective was to evaluate elephant grass (Pennisetum purpureum Schum. pastures, under the agroecological and conventional systems, as forage mass and stocking rate. In the agroecological system, the elephant grass was established in rows spaced by 3.0 m from each other. During the cool season ryegrass (Lolium multiflorum Lam. was established between these rows, which allowed the development of spontaneous growth species during the warm season. In the conventional system the elephant grass was established singularly in rows spaced 1.4 m from each other. Organic and chemical fertilizers were applied at 150 kg of N/ha/year with in the pastures under agroecological and conventional systems, respectively. Lactating Holstein cows which received 5.0 kg/day supplementary concentrate feed were used for evaluation. The experimental design was completely randomized, with two treatments (agroecological and conventional systems two replications (paddocks and independent evaluations (grazing cycles. The pastures were used during the whole year for the agroecological system and for 195 days in the conventional year. The average values of forage mass were 3.5 and 4.2 t/ha and the stocking rates were 2.08 and 3.23 AU/ha for the respective systems. The results suggest that the use of the elephant grass under the agroecological system allows for best distribution of forage and stocking rate to be more uniform throughout the year than the use of elephant grass in conventional system.

  16. Microsatellite genetic diversity and differentiation of native and introduced grass carp populations in three continents

    Science.gov (United States)

    Chapman, Duane C.; Chen, Qin; Wang, Chenghui; Zhao, Jinlian; Lu, Guoqing; Zsigmond, Jeney; Li, Sifa

    2012-01-01

    Grass carp (Ctenopharyngodon idella), a freshwater species native to China, has been introduced to about 100 countries/regions and poses both biological and environmental challenges to the receiving ecosystems. In this study, we analyzed genetic variation in grass carp from three introduced river systems (Mississippi River Basin in US, Danube River in Hungary, and Tone River in Japan) as well as its native ranges (Yangtze, Pearl, and Amur Rivers) in China using 21 novel microsatellite loci. The allelic richness, observed heterozygosity, and within-population gene diversity were found to be lower in the introduced populations than in the native populations, presumably due to the small founder population size of the former. Significant genetic differentiation was found between all pairwise populations from different rivers. Both principal component analysis and Bayesian clustering analysis revealed obvious genetic distinction between the native and introduced populations. Interestingly, genetic bottlenecks were detected in the Hungarian and Japanese grass carp populations, but not in the North American population, suggesting that the Mississippi River Basin grass carp has experienced rapid population expansion with potential genetic diversification during the half-century since its introduction. Consequently, the combined forces of the founder effect, introduction history, and rapid population expansion help explaining the observed patterns of genetic diversity within and among both native and introduced populations of the grass carp.

  17. Molecular biomarkers for grass pollen immunotherapy.

    Science.gov (United States)

    Popescu, Florin-Dan

    2014-03-26

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.

  18. Role of carbohydrate metabolism in grass tetany

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.K.; Madsen, F.C.; Lentz, D.E.; Hansard, S.L.

    1977-01-01

    Clinical hypomagnesemia is confined primarily to beef cattle in the United States but also occurs in dairy cattle in other countries, probably due to different management practices. During periods when grass tetany is likely, early vegetative temperate zone grasses are usually low in total readily available carbohydrates and magnesium but high in potassium and nitrogen. The tetany syndrome may include hypoglycemia and ketosis, suggesting an imbalance in intermediary energy metabolism. Many enzyme systems critical to cellular metabolism, including those which hydrolyze and transfer phosphate groups, are activated by Mg. Thus, by inference, Mg is required for normal glucose utilization, fat, protein, nucleic acid and coenzyme synthesis, muscle contraction, methyl group transfer, and sulfate, acetate, and formate activation. Numerous clinical and experimental studies suggest an intimate relationship between metabolism of Mg and that of carbohydrate, glucagon, and insulin. The objective is to review this literature and suggest ways in which these relationships might contribute to a chain of events leading to grass tetany.

  19. Diet Switching by Mammalian Herbivores in Response to Exotic Grass Invasion.

    Science.gov (United States)

    Bremm, Carolina; Carvalho, Paulo C F; Fonseca, Lidiane; Amaral, Glaucia A; Mezzalira, Jean C; Perez, Naylor B; Nabinger, Carlos; Laca, Emilio A

    2016-01-01

    Invasion by exotic grasses is a severe threat to the integrity of grassland ecosystems all over the world. Because grasslands are typically grazed by livestock and wildlife, the invasion is a community process modulated by herbivory. We hypothesized that the invasion of native South American grasslands by Eragrostis plana Nees, an exotic tussock-forming grass from Africa, could be deterred by grazing if grazers switched dietary preferences and included the invasive grass as a large proportion of their diets. Bos taurus (heifers) and Ovis aries (ewes) grazed plots with varying degrees of invasion by E. plana in a replicated manipulative experiment. Animal positions and species grazed were observed every minute in 45-min grazing session. Proportion of bites and steps in and out of E. plana tussocks were measured and used to calculate several indices of selectivity. Both heifers and ewes exhibited increasing probability of grazing E. plana as the proportion of area covered by tussocks increased, but they behaved differently. In agreement with expectations based on the allometry of dietary preferences and morphology, ewes consumed a low proportion of E. plana, except in areas that had more than 90% E. plana cover. Heifers consumed proportionally more E. plana than ewes. Contrary to our hypothesis, herbivores did not exhibit dietary switching towards the invasive grass. Moreover, they exhibited avoidance of the invasive grass and preference for short-statured native species, both of which should tend to enhance invasion. Unless invasive plants are highly palatable to livestock, the effect of grazing to deter the invasion is limited, due to the inherent avoidance of the invasive grass by the main grazers in the ecosystem, particularly sheep.

  20. Cloning and preliminary functional studies of the JAM-A gene in grass carp (Ctenopharyngodon idellus).

    Science.gov (United States)

    Du, Fukuan; Su, Jianguo; Huang, Rong; Liao, Lanjie; Zhu, Zuoyan; Wang, Yaping

    2013-06-01

    Grass carp (Ctenopharyngodon idellus) is a very important aquaculture species in China and other South-East Asian countries; however, disease outbreaks in this species are frequent, resulting in huge economic losses. Grass carp hemorrhage caused by grass carp reovirus (GCRV) is one of the most serious diseases. Junction adhesion molecule A (JAM-A) is the mammalian receptor for reovirus, and has been well studied. However, the JAM-A gene in grass carp has not been studied so far. In this study, we cloned and elucidated the structure of the JAM-A gene in grass carp (GcJAM-A) and then studied its functions during grass carp hemorrhage. GcJAM-A is composed of 10 exons and 9 introns, and its full-length cDNA is 1833 bp long, with an 888 bp open reading frame (ORF) that encodes a 295 amino acid protein. The GcJAM-A protein is predicted to contain a typical transmembrane domain. Maternal expression pattern of GcJAM-A is observed during early embryogenesis, while zygote expression occurs at 8 h after hatching. GcJAM-A is expressed strongly in the gill, liver, intestine and kidney, while it is expressed poorly in the blood, brain, spleen and head kidney. Moreover, lower expression is observed in the gill, liver, intestine, brain, spleen and kidney of 30-month-old individuals, compared with 6-month-old. In a GcJAM-A-knockdown cell line (CIK) infected with GCRV, the expression of genes involved in the interferon and apoptosis pathways was significantly inhibited. These results suggest that GcJAM-A could be a receptor for GCRV. We have therefore managed to characterize the GcJAM-A gene and provide evidence for its role as a receptor for GCRV.

  1. Technology Optimization of Enzymolysis of Burmuda Grass

    Directory of Open Access Journals (Sweden)

    Liu Jun-Hong

    2014-03-01

    Full Text Available Cellulose can be degraded by enzyme to glucose, which provide carbon source for ethanol fermentation. This study, taking Burmuda grass as material, analyzed effects of temperature, time, pH, PBS dosage and ratio of enzyme on reducing sugar. It came to the conclusion that the best conditions of the enzymolysis of Burmuda grass are as follows: 50°C for temperature, 32 h for time, 4.20 for pH, 2 mL for PBS dosage, 4:3 for the ratio of xylanase and cellulase, the yield of reducing sugar reached 78.63%.

  2. Biomethanation of Carpet Grass (Axonopus fissifolius)

    OpenAIRE

    Chima Ngumah; Jude Ogbulie; Justina Orji; Ekperechi Amadi

    2013-01-01

    Axonopus fissifolius commonly called “carpet grass” was subjected to anaerobic digestion for 30 days. Anaerobic digestion was carried out in a batch-fed process at the ambient temperature of 27-290C. Biomethane measurements were obtained by measuring the volume displacement of a saturated filtered calcium hydroxide solution in a transparent calibrated vessel.  42.7g of fresh carpet grass clippings yielded 1.955 L of biomethane. Biomethane potential (BMP) of carpet grass for a 30 day anaerobic...

  3. Plastic traits of an exotic grass contribute to its abundance but are not always favourable.

    Directory of Open Access Journals (Sweden)

    Jennifer Firn

    Full Text Available In herbaceous ecosystems worldwide, biodiversity has been negatively impacted by changed grazing regimes and nutrient enrichment. Altered disturbance regimes are thought to favour invasive species that have a high phenotypic plasticity, although most studies measure plasticity under controlled conditions in the greenhouse and then assume plasticity is an advantage in the field. Here, we compare trait plasticity between three co-occurring, C(4 perennial grass species, an invader Eragrostis curvula, and natives Eragrostis sororia and Aristida personata to grazing and fertilizer in a three-year field trial. We measured abundances and several leaf traits known to correlate with strategies used by plants to fix carbon and acquire resources, i.e. specific leaf area (SLA, leaf dry matter content (LDMC, leaf nutrient concentrations (N, C:N, P, assimilation rates (Amax and photosynthetic nitrogen use efficiency (PNUE. In the control treatment (grazed only, trait values for SLA, leaf C:N ratios, Amax and PNUE differed significantly between the three grass species. When trait values were compared across treatments, E. curvula showed higher trait plasticity than the native grasses, and this correlated with an increase in abundance across all but the grazed/fertilized treatment. The native grasses showed little trait plasticity in response to the treatments. Aristida personata decreased significantly in the treatments where E. curvula increased, and E. sororia abundance increased possibly due to increased rainfall and not in response to treatments or invader abundance. Overall, we found that plasticity did not favour an increase in abundance of E. curvula under the grazed/fertilized treatment likely because leaf nutrient contents increased and subsequently its' palatability to consumers. E. curvula also displayed a higher resource use efficiency than the native grasses. These findings suggest resource conditions and disturbance regimes can be manipulated to

  4. A specific CpG oligodeoxynucleotide induces protective antiviral responses against grass carp reovirus in grass carp Ctenopharyngodon idella.

    Science.gov (United States)

    Su, Hang; Yuan, Gailing; Su, Jianguo

    2016-07-01

    CpG oligodeoxynucleotides (ODNs) show strong immune stimulatory activity in vertebrate, however, they possess specific sequence feature among species. In this study, we screened out an optimal CpG ODN sequence for grass carp (Ctenopharyngodon idella), 1670A 5'-TCGAACGTTTTAACGTTTTAACGTT-3', from six published sequences and three sequences designed by authors based on grass carp head kidney mononuclear cells and CIK (C. idella kidney) cells proliferation. VP4 mRNA expression was strongly inhibited by CpG ODN 1670A in CIK cells with GCRV infection, showing its strong antiviral activity. The mechanism via toll-like receptor 9 (TLR9)-mediated signaling pathway was measured by real-time quantitative RT-PCR, and TLR21 did not play a role in the immune response to CpG ODN. The late up-regulation of CiRIG-I mRNA expression indicated that RIG-I-like receptors (RLRs) signaling pathway participated in the immune response to CpG ODN which is the first report on the interaction between CpG and RLRs. We also found that the efficient CpG ODN can activates interferon system. Infected with GCRV, type I interferon expression was reduced and type II interferon was induced by the efficient CpG ODN in CIK cells, especially IFNγ2, suggesting that IFNγ2 played an important role in response to the efficient CpG ODN. These results provide a theoretical basis and new development trend for further research on CpG and the application of CpG vaccine adjuvant in grass carp disease control. PMID:26972738

  5. Nowcasting daily minimum air and grass temperature

    Science.gov (United States)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) errors for grass minimum temperature and the 4-h nowcasts.

  6. MoDest GrassUp

    DEFF Research Database (Denmark)

    Jørgensen, Rasmus Nyholm; S. Nadimi, Esmaeil

    2010-01-01

    The Technology The technology is one of a kind, as there is no such mathematical model estimating animal feed uptake available today. The estimation of grass uptake, is based on real time wireless sensor data, cow merit and climate data. Relevant cow behaviour data (such as location, movement vel...

  7. Scaling water use of perennial grasses from the plot to Midwestern U.S.

    Science.gov (United States)

    Bernacchi, C. J.; VanLoocke, A. D.; Hickman, G. C.; Zeri, M.; Twine, T. E.

    2011-12-01

    Perennial rhizomatous C4 grasses are currently considered, in many regions, one of the most promising vegetation types to supply biomass for bioenergy production. Because one goal of bioenergy production is to benefit the environment, the potential environmental impacts and services that would be associated with large scale production must be investigated. Of particular interest is the impact that altering the composition of vegetation at the landscape scale would have on regional hydrological cycles driven by higher rates of evapotranspiration (ET). To assess this, we implemented micrometeorological measurements using two independent techniques over multiple growing seasons for replicated plots of two perennial rhizomatous grasses, Miscanthus giganteus (miscanthus) and Panicum virgatum (switchgrass), and two traditional crop species, Zea mays (maize) and Glycine Max (soybean), planted throughout Central Illinois. When averaged across the entire growing season, ET for miscanthus was double relative to annual crops, and 140% of P. virgatum ET. The differences between the perennial grasses and annual crops were primarily due to longer growing season associated with the perennial grasses, but Miscanthus also demonstrated higher instantaneous water use. These results, coupled with physiological measurements of these species, were then used to parameterize and validate a dynamic vegetation model, Agro-IBIS, to investigate the large-scale consequences of land-use change on ecosystem hydrology from existing agriculture to various perennial grass production scenarios ranging from 10% to 100%. Results show that uniform production scenarios of less than 25% have little impact on regional hydrology but 'hotspots' with higher percentage land cover devoted to perennial grasses can have important consequences in localized areas. Given the increasing demand on water, we investigated whether the increased carbon gain associated with bioenergy crops was sufficient to offset the

  8. Dynamic evolution of rht-1 homologous regions in grass genomes.

    Directory of Open Access Journals (Sweden)

    Jing Wu

    Full Text Available Hexaploid bread wheat contains A, B, and D three subgenomes with its well-characterized ancestral genomes existed at diploid and tetraploid levels, making the wheat act as a good model species for studying evolutionary genomic dynamics. Here, we performed intra- and inter-species comparative analyses of wheat and related grass genomes to examine the dynamics of homologous regions surrounding Rht-1, a well-known "green revolution" gene. Our results showed that the divergence of the two A genomes in the Rht-1 region from the diploid and tetraploid species is greater than that from the tetraploid and hexaploid wheat. The divergence of D genome between diploid and hexaploid is lower than those of A genome, suggesting that D genome diverged latter than others. The divergence among the A, B and D subgenomes was larger than that among different ploidy levels for each subgenome which mainly resulted from genomic structural variation of insertions and, perhaps deletions, of the repetitive sequences. Meanwhile, the repetitive sequences caused genome expansion further after the divergence of the three subgenomes. However, several conserved non-coding sequences were identified to be shared among the three subgenomes of wheat, suggesting that they may have played an important role to maintain the homolog of three subgenomes. This is a pilot study on evolutionary dynamics across the wheat ploids, subgenomes and differently related grasses. Our results gained new insights into evolutionary dynamics of Rht-1 region at sequence level as well as the evolution of wheat during the plolyploidization process.

  9. Responses of savanna lawn and bunch grasses to water limitation

    NARCIS (Netherlands)

    van der Plas, Alfons; Zeinstra, Patricia; Veldhuis, Michiel; Fokkema, Rienk; Tielens, Elske; Howison, Ruth; Olff, Han

    2013-01-01

    The grass layer of African savannas consists of two main vegetation types: grazing lawns, dominated by short, mostly clonally reproducing grasses, and bunch grasslands, dominated by tall bunch grasses. This patchy distribution of vegetation types is mostly created by large herbivores, which selectiv

  10. 7 CFR 1437.310 - Sea grass and sea oats.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  11. Root proliferation in native perennial grasses of arid Patagonia, Argentina

    Institute of Scientific and Technical Information of China (English)

    Yanina A. TORRES; Mara M. MUJICA; Sandra S. BAIONI; Jos ENTO; Mara N. FIORETTI; Guillermo TUCAT; Carlos A. BUSSO; Oscar A. MONTENEGRO; Leticia ITHURRART; Hugo D. GIORGETTI; Gustavo RODRGUEZ; Diego BENTIVEGNA; Roberto E. BREVEDAN; Osvaldo A. FERNNDEZ

    2014-01-01

    Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that (1) defoliation reduce net primary productivity, and root length density and weight in the native species, and (2) root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species (i.e., Aristida spegazzinii, A. subulata and Sporobolus cryptandrus). Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season (2008-2009), cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid-and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den-sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

  12. A Tensile Strength of Bermuda Grass and Vetiver Grass in Terms of Root Reinforcement Ability Toward Soil Slope Stabilization

    Science.gov (United States)

    Noorasyikin, M. N.; Zainab, M.

    2016-07-01

    An examination on root characteristics and root properties has been implemented in this study. Two types of bioengineering were chose which are Vetiver grass and Bermuda grass as these grasses were widely applied for slope stabilization. The root samples were taken to the laboratory to investigate its classification, characteristics and strength. The root of both grasses was found grow with fibrous root matrix system. In terms of root anchorage, the root matrix system of Vetiver grass was exhibits more strengthen than the Bermuda grass. However, observation on root image from Scanning Electron Microscope test reveals that the root of Vetiver grass becomes non-porous as the moisture content reduced. Meanwhile, the root tensile strength of Bermuda grass was obtained acquired low value with higher percentage of moisture content, root morphology and bonding strength. The results indicated that the root tensile strength is mainly influence by percentage of moisture content and root morphology.

  13. Investigation into the Effect of Molds in Grasses on Their Content of Low Molecular Mass Thiols

    Directory of Open Access Journals (Sweden)

    Adam Nawrath

    2012-10-01

    Full Text Available The aim of this study was to investigate the effect of molds on levels of low molecular mass thiols in grasses. For this purpose, the three grass species Lolium perenne, Festulolium pabulare and Festulolium braunii were cultivated and sampled during four months, from June to September. The same species were also grown under controlled conditions. High-performance liquid chromatography with electrochemical detection was used for quantification of cysteine, reduced (GSH and oxidized (GSSG glutathione, and phytochelatins (PC2, PC3, PC4 and PC5. Data were statistically processed and analyzed. Thiols were present in all examined grass species. The effect of fungicide treatments applied under field conditions on the content of the evaluated thiols was shown to be insignificant. Species influenced (p < 0.05 PC3 and GSSG content. F. pabulare, an intergeneric hybrid of drought- and fungi-resistant Festuca arundinacea, was comparable in PC3 content with L. perenne and F. braunii under field conditions. Under controlled conditions, however, F. pabulare had higher (p < 0.05 PC3 content than did L. perenne and F. braunii. Under field conditions, differences between the evaluated species were recorded only in GSSG content, but only sampling in June was significant. F. pabulare had higher (p < 0.05 GSSG content in June than did L. perenne and F. braunii.

  14. Classification of grass pollen through the quantitative analysis of surface ornamentation and texture.

    Science.gov (United States)

    Mander, Luke; Li, Mao; Mio, Washington; Fowlkes, Charless C; Punyasena, Surangi W

    2013-11-01

    Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material.

  15. Volatile organic compound emissions from elephant grass and bamboo cultivars used as potential bioethanol crop

    Science.gov (United States)

    Crespo, E.; Graus, M.; Gilman, J. B.; Lerner, B. M.; Fall, R.; Harren, F. J. M.; Warneke, C.

    2013-02-01

    Volatile organic compound (VOC) emissions from elephant grass (Miscanthus gigantus) and black bamboo (Phyllostachys nigra) were measured online in semi-field chamber and plant enclosure experiments during growth and harvest using proton-transfer reaction mass spectrometry (PTR-MS), proton-transfer reaction ion-trap mass spectrometry (PIT-MS) and gas chromatography-mass spectrometry (GC-MS). Both cultivars are being considered for second-generation biofuel production. Before this study, no information was available on their yearly VOC emissions. This exploratory investigation shows that black bamboo is a strong isoprene emitter (daytime 28,516 ng gdwt-1 h-1) and has larger VOC emissions, especially for wound compounds from the hexanal and hexenal families, than elephant grass. Daytime emissions of methanol, acetaldehyde, acetone + propanal and acetic acid of black bamboo were 618, 249, 351, and 1034 ng gdwt-1 h-1, respectively. In addition, it is observed that elephant grass VOC emissions after harvesting strongly depend on the seasonal stage. Not taking VOC emission variations throughout the season for annual and perennial species into account, may lead to an overestimation of the impact on local air quality in dry periods. In addition, our data suggest that the use of perennial grasses for extensive growing for biofuel production have lower emissions than woody species, which might be important for regional atmospheric chemistry.

  16. Meiosis in elephant grass (Pennisetum purpureum, pearl millet (Pennisetum glaucum (Poaceae, Poales and their interspecific hybrids

    Directory of Open Access Journals (Sweden)

    Vânia Helena Techio

    2006-01-01

    Full Text Available The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28 and Pennisetum glaucum (pearl millet, 2n = 2x = 14 can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these species is infertility due to triploidy (2n = 3x = 21. This study describes meiosis in elephant grass x pearl millet hybrids and their progenitors. Panicles were prepared according to the conventional protocol for meiotic studies and Alexander’s stain was used for assessing pollen viability. Pearl millet accessions presented regular meiosis with seven bivalents and high pollen viability. For elephant grass, 14 bivalents in diakinesis and metaphase I were observed. The BAG 63 elephant grass accession, derived from tissue culture, presented a high frequency of meiotic abnormalities. The three hybrid accessions presented a high frequency of abnormalities characterized by irregular chromosomal segregation which resulted in the formation of sterile pollen.

  17. Productivity and nutritional quality of Flechinha grass ( Echinolaena inflexa ), native grass of Brazilian Cerrado

    OpenAIRE

    Sylvia Rocha e Silveira; Rafael Sandin Ribeiro; João Paulo Sacramento; Domingos Sávio Campos Paciullo; Luiz Gustavo Ribeiro Pereira; Rogério Martins Maurício

    2016-01-01

    ABSTRACT: Due to scarce nutritional data, this study assessed the productivity and nutritional value of Echinolaena inflexa (EI) grass, native to the Cerrado biome. It was compared to B. brizantha (BB), one of the most cultivated grasses in Brazil, during a whole year (rainy; RS and dry season; DS). Sampling was held in accordance with pasture management (entry / exit height; 50 / 5cm and 80 / 25cm for EI and BB, respectively). Dry matter production (DMP), crude protein (CP), neutral and acid...

  18. Estimating grass and grass silage degradation characteristics by in situ and in vitro gas production methods

    Directory of Open Access Journals (Sweden)

    Danijel Karolyi

    2010-01-01

    Full Text Available Fermentation characteristics of grass and grass silage at different maturities were studied using in situ and in vitro gas production methods. In situ data determined difference between grass and silage. Degradable fraction decreased as grass matured while the undegradable fraction increased. Rate of degradation (kd was slower for silage than fresh grass. Gas production method (GP data showed that fermentation of degradable fraction was different between stage of maturity in both grass and silage. Other data did not show any difference with the exception for the rate of GP of soluble and undegradable fraction. The in situ degradation characteristics were estimated from GP characteristics. The degradable and undegradable fractions could be estimated by multiple relationships. Using the three-phases model for gas production kd and fermentable organic matter could be estimated from the same parameters. The only in situ parameter that could not be estimated with GP parameters was the soluble fraction. The GP method and the three phases model provided to be an alternative to the in situ method for animal feed evaluations.

  19. PHYTOSOCIOLOGY AND ECOLOGY OF THE NATURAL DRY-GRASS COMMUNITIES ON OAHU, HAWAII

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    Kuswata - Kartawinata

    2014-01-01

    Full Text Available Using the Braun-Blanquet and ordination techniques, nine dry-grass community types were recognized on Oahu, seven of which were dominated by exotic grasses and two by native grasses, Hctcrnpogna eontortus and Erarjrostis variabilis. These community types occured in summer-drought, summer-dry and humid climates. The distribution of certain community types could be correlated directly with rainfall and soil pH. In the summer-drought climate the occurrence of the community types was related to topography, wind exposure, rockiness of the land surface and stoniness of the soil. The nine community types were not related to the established soil series, organic matter content and watsr retaining' capacity of the  surface  soils.Three distinct soil-water regimes were recognized in five community types: drought, dry and wet types. Seasonal variations in soil-water content were correlated closely  with   the   rainfall   pattern.The introduction and spread of exotic species resulted in a gradual disappearance of the native grass communities in the summer-drought zone. In the summer-dry zone, Grevillea robiista. trees and Meliiiis minutiflora grass mats were invading the Rhynchelytrum repens community. Artdropogon virginiciis, introduced in 1932, formed a wide spread herbaceous community in the humid zone. In some places, this community was invaded by Dicranopteris linearis fern mats and trees of Acacia, koa or Metrosideros collina. Fire in both the summer-dry and humid zones maintained and extended  the  grass communities.

  20. A REVIEW ON LEMON GRASS: AGRICULTURAL AND MEDICINAL ASPECT

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    Vaibhav Srivastava

    2013-08-01

    Full Text Available Lemongrass (Cymbopogan flexuosus and Cymbopogan Citraus is regarded as one of the grass which is commonly available in India and abroad. It is widely used in different conditions of pain and discomfort. The oil (Lemongrass oil obtained from the grass has diverse medicinal value. It also produces semi-synthetic Vitamin A that reduces the risk of Xerophthalmia and Night blindness. The grass has great benefits to mankind as it revitalizes the body and mind, helps with infections and act as muscle and skin toner. This review will explore the plant / grass and also suggest for more cultivation of the grass because of its medicinal importance.

  1. Effect of leucaena row spacing and cutting height on yield and chemical compositions of three associated grasses intercropped with leucaena

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    Tudsri, S.

    2002-07-01

    Full Text Available The experiment was conducted at Suwanvajokkasikit Research Station, Pakchong, to determine the yield and chemical compositions of ruzi (Brachiaria ruziziens, dwarf napier (Pennisetum purpureum, and Taiwan A25 (P. purpureum intercropped with leucaena (Leucaena leucocephala cv. Ivory Coast under irrigation. The design of the experiment was a randomized split-split plot with pasture species as the main plots, leucaena row spacings (1, 2, 4 m as sub - plots and leucaena cutting height (10 and 25 cm above ground levels as sub-sub-plots with three replications of 5 × 4 m sub-sub-plots. Dwarf napier produced the highest total dry matter yield, followed by Taiwan A25 and ruzi. Leucaena yield was highest in the ruzi plots and lowest in the dwarf napier plots. However, the total dry matter yield (grass + leucaena was highest in the dwarf napier plot and lowest in the ruzi plots. Increasing the row spacing between rows of leucaena resulted in a poorer leucaena yield but the reverse was true for the grasses. The recommendation for row spacing of leucaena was 1 m under irrigation conditions. Cutting of leucaena at 10 cm above ground levels depressed yield of leucaena but did not affect the associated grasses. In terms of chemical compositions it was found that the crude protein of the dwarf napier and Taiwan A25 were higher than that of the ruzi grass. Leucaena gave higher levels of crude protein than the grasses. The phosphorus and potassium levels of the grasses were higher than leucaena. ADF levels were higher in the grasses than in the legumes. Nutrient contents of grasses and leucaena were not affected by leucaena row spacing and cutting height.

  2. Inter-sexual competition in a dioecious grass.

    Science.gov (United States)

    Mercer, Charlene A; Eppley, Sarah M

    2010-11-01

    Spatial segregation of the sexes (SSS) occurs in many dioecious angiosperms, but little data are available on the fitness advantages, if any, for males and females. We examined whether reciprocally transplanted male and female seedlings of Distichlis spicata, a dioecious grass species that exhibits extreme SSS, differed in their responses to microhabitats and competition treatments. Plants grown without conspecific competitors grew equally well in both male- or female-majority habitats, suggesting that male and female plants do not have differential resource needs at the juvenile life-history stage. However, plants subject to intra-sexual competition were significantly larger than plants subject to inter-sexual competition, suggesting that niche partitioning may occur in D. spicata.

  3. MINERAL HORIZONS, ELECTROMAGNETIC FIELDS AND CIRCULAR SHAPES IN THE GRASS

    Directory of Open Access Journals (Sweden)

    Valentino Straser

    2009-12-01

    Full Text Available The occasional appearance of circular shapes in meadows and farmland located on slopes usually affected by gravitational phenomena, offered an occasion for verifying the possible relation between the position of the circles in the grass, the gravitational movement of the slope affecting its mineral horizons and the variations of electric and static magnetic fields close to the circular shapes and in the surrounding area. The stress caused by the “creeping” movement in the uderlying ground turned out to be in direct relation with the variation in the electric and magnetic fields caused by piezoelectric and piezomagnetic minerals such as quartz. The onset of the electromagnetic process involves the conversion of electric energy on the surface into an area of spherical shape which is linked with a different growth of herbaceous species compared to the surrounding vegetation.

  4. Pollutant tracking for 3 Western North Atlantic sea grasses by remote sensing: Preliminary diminishing white light responses of Thalassia testudinum, Halodule wrightii, and Zostera marina

    International Nuclear Information System (INIS)

    Highlights: • Sea grass accessory pigments are more important than Chl at medium to low light intensity. • Partial absorption changes in Thalassia and also in Halodule at low intensity visible light ranges. • NDVI and chlNDI do not detect these changes or low light responses of sea grasses. • Intertidal sea grasses are less stressed than the subtidal species at low and high light. • Chl b is an important photosynthetic pigment in tropical/subtropical species. - Abstract: Sea grasses are foundation species for estuarine ecosystems. The available light for sea grasses diminishes rapidly during pollutant spills, effluent releases, disturbances such as intense riverine input, and tidal changes. We studied how sea grasses’ remote-sensing signatures and light-capturing ability respond to short term light alterations. In vivo responses were measured over the entire visible-light spectra to diminishing white-light on whole-living-plants’ spectral reflectance, including 6 h of full oceanic-light fluences from 10% to 100%. We analyzed differences by various reflectance indices. We compared the sea grasses species responses of tropical vs. temperate and intertidals (Halodule wrightii, and Zostera marina) vs. subtidal (Thalassia testudinum). Reflectance diminished with decreasing light intensity that coincided with greater accessory pigment stimulation (anthocyanin, carotenoids, xanthins). Chlorophyll a and Chlorophyll b differed significantly among species (Thalassia vs. Halodule). Photosynthetic efficiency diminished at high light intensities. The NDVI index was inadequate to perceive these differences. Our results demonstrate the leaf-level utility of data to remote sensing for mapping sea grass and sea grass stress

  5. Traffic-related trace element accumulation in roadside soils and wild grasses in the Qinghai-Tibet Plateau, China.

    Science.gov (United States)

    Wang, Guanxing; Yan, Xuedong; Zhang, Fan; Zeng, Chen; Gao, Dan

    2013-12-30

    This research examines traffic-source trace elements accumulations and distributions in roadside soils and wild grasses in the Qinghai-Tibet Plateau. A total of 100 soil samples and 100 grass samples including Achnatherum splendens, Anaphalis nepalensis, Artemisia sphaerocephala, Carex moorcroftii, Iris lacteal, Kobresia myosuroides, Oreosolen wattii, Oxytropis ochrocephala and Stellera chamaejasme were collected at 100 sites from different road segments. The contents of metals and metalloids, including Cu, Zn, Cd, Pb, Cr, Co, Ni and As, in the soil and grass samples were analyzed using ICP-MS. The total mean concentrations of the eight trace elements in soils are Cu (22.84 mg/kg), Zn (100.56 mg/kg), Cd (0.28 mg/kg), Pb (28.75 mg/kg), Cr (36.82 mg/kg), Co (10.24 mg/kg), Ni (32.44 mg/kg) and As (21.43 mg/kg), while in grasses are Cu (9.85 mg/kg), Zn (31.47 mg/kg), Cd (0.05 mg/kg), Pb (2.06 mg/kg), Cr (14.16 mg/kg), Co (0.55 mg/kg), Ni (4.03 mg/kg) and As (1.33 mg/kg). The metal and metalloid concentrations in the nine grass species were all below the critical values of hyperaccumulators. The mean values and Multivariate Analysis of Variance (MANOVA) results indicate that: (1) the concentrations of the trace elements in the soils are higher than those in the grasses, (2) the concentrations of Cu, Zn, Cd, Pb in the soils decrease as the roadside distance increases, (3) the concentrations of trace elements in the grasses are the highest at 10 m from the road edge, (4) the higher the traffic volume, the higher the concentrations of the trace elements in the roadside soils and grasses, and (5) when the land cover is meadow, the lower the sand content in the soil, the lower the trace element concentrations. With a trace element's bioavailability represented by its transfer factor (TF) from the soil to the grass, the TFs of the eight trace elements are not in the same orders for different grass species.

  6. Traffic-Related Trace Element Accumulation in Roadside Soils and Wild Grasses in the Qinghai-Tibet Plateau, China

    Directory of Open Access Journals (Sweden)

    Guanxing Wang

    2013-12-01

    Full Text Available This research examines traffic-source trace elements accumulations and distributions in roadside soils and wild grasses in the Qinghai-Tibet Plateau. A total of 100 soil samples and 100 grass samples including Achnatherum splendens, Anaphalis nepalensis, Artemisia sphaerocephala, Carex moorcroftii, Iris lacteal, Kobresia myosuroides, Oreosolen wattii, Oxytropis ochrocephala and Stellera chamaejasme were collected at 100 sites from different road segments. The contents of metals and metalloids, including Cu, Zn, Cd, Pb, Cr, Co, Ni and As, in the soil and grass samples were analyzed using ICP-MS. The total mean concentrations of the eight trace elements in soils are Cu (22.84 mg/kg, Zn (100.56 mg/kg, Cd (0.28 mg/kg, Pb (28.75 mg/kg, Cr (36.82 mg/kg, Co (10.24 mg/kg, Ni (32.44 mg/kg and As (21.43 mg/kg, while in grasses are Cu (9.85 mg/kg, Zn (31.47 mg/kg, Cd (0.05 mg/kg, Pb (2.06 mg/kg, Cr (14.16 mg/kg, Co (0.55 mg/kg, Ni (4.03 mg/kg and As (1.33 mg/kg. The metal and metalloid concentrations in the nine grass species were all below the critical values of hyperaccumulators. The mean values and Multivariate Analysis of Variance (MANOVA results indicate that: (1 the concentrations of the trace elements in the soils are higher than those in the grasses, (2 the concentrations of Cu, Zn, Cd, Pb in the soils decrease as the roadside distance increases, (3 the concentrations of trace elements in the grasses are the highest at 10 m from the road edge, (4 the higher the traffic volume, the higher the concentrations of the trace elements in the roadside soils and grasses, and (5 when the land cover is meadow, the lower the sand content in the soil, the lower the trace element concentrations. With a trace element's bioavailability represented by its transfer factor (TF from the soil to the grass, the TFs of the eight trace elements are not in the same orders for different grass species.

  7. Biomethanation of Carpet Grass (Axonopus fissifolius

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    Chima Ngumah

    2014-01-01

    Full Text Available Axonopus fissifolius commonly called “carpet grass” was subjected to anaerobic digestion for 30 days. Anaerobic digestion was carried out in a batch-fed process at the ambient temperature of 27-290C. Biomethane measurements were obtained by measuring the volume displacement of a saturated filtered calcium hydroxide solution in a transparent calibrated vessel.  42.7g of fresh carpet grass clippings yielded 1.955 L of biomethane. Biomethane potential (BMP of carpet grass for a 30 day anaerobic digestion was 0.05 m3 CH4 kg-1 TS. The rates of biomethane potentials for the first, second, third, fourth and fifth six-day intervals were 1.5mL g-1 TS (2.81%, 6.4mL g-1 TS (14.58%, 16.1mL g-1 TS (30.18%, 17.74mL g-1 TS (33.25%, and 10.23mL g-1 TS (19.81% respectively. The total solids, volatile solids and pH of feedstock and digestate were 85.80% and 85.56%, 90.91% and 87.58%, 6.6 (27oC and 6.9 (27oC respectively.  The relatively high biomethane potential of carpet grass at the ambient temperature presented in this paper depicts anaerobic digestion as a viable means of profitably treating grass waste for both sanitation and generating biomethane especially in the tropics where the ambient temperatures are usually favourable for optimum biomethanation for most part of the year, thus making the process affordable and less cumbersome.DOI http://dx.doi.org/10.5755/j01.erem.66.4.5228

  8. Biomethanation of Carpet Grass (Axonopus fissifolius

    Directory of Open Access Journals (Sweden)

    Chima Ngumah

    2013-12-01

    Full Text Available Axonopus fissifolius commonly called “carpet grass” was subjected to anaerobic digestion for 30 days. Anaerobic digestion was carried out in a batch-fed process at the ambient temperature of 27-290C. Biomethane measurements were obtained by measuring the volume displacement of a saturated filtered calcium hydroxide solution in a transparent calibrated vessel. 42.7g of fresh carpet grass clippings yielded 1.955 L of biomethane. Biomethane potential (BMP of carpet grass for a 30 day anaerobic digestion was 0.05 m3 CH4 kg-1 TS. The rates of biomethane potentials for the first, second, third, fourth and fifth six-day intervals were 1.5mL g-1 TS (2.81%, 6.4mL g-1 TS (14.58%, 16.1mL g-1 TS (30.18%, 17.74mL g-1 TS (33.25%, and 10.23mL g-1 TS (19.81% respectively. The total solids, volatile solids and pH of feedstock and digestate were 85.80% and 85.56%, 90.91% and 87.58%, 6.6 (27oC and 6.9 (27oC respectively. The relatively high biomethane potential of carpet grass at the ambient temperature presented in this paper depicts anaerobic digestion as a viable means of profitably treating grass waste for both sanitation and generating biomethane especially in the tropics where the ambient temperatures are usually favourable for optimum biomethanation for most part of the year, thus making the process affordable and less cumbersome.

  9. Effect of simulated acid rain stress on germination of four turf grass seeds%模拟酸雨胁迫对4种草坪草种子萌发的影响

    Institute of Scientific and Technical Information of China (English)

    田如男; 张培东; 程澄

    2011-01-01

    以中性溶液(pH =7.0)为对照,研究了模拟酸雨(pH为2.0、2.5、3.0、3.5、4.0、5.0)胁迫对黑麦草(Lolium perenne)、高羊茅(Festuca arundinacea)、匍匐剪股颖(Agrostis palustris)和狗牙根(Cynodon dactylon)4种多年生草坪草种子萌发的影响.结果表明:酸雨胁迫对4种草坪草种子萌发的影响不同,pH =2.0的酸雨完全抑制了4种草坪草种子的萌发,表现为发芽率、发芽势、活力指数均为零.黑麦草、高羊茅种子能在pH:≥2.5的酸雨胁迫下正常萌发,匍匐剪股颖种子能在pH≥3.0的酸雨胁迫下正常萌发,狗牙根种子在不同程度酸雨胁迫下均萌发不良.此外,酸雨胁迫还延缓了4种草坪草种子的萌发进程.应用主成分分析和隶属函数分析法对4种草坪草种子抗酸雨胁迫能力进行综合评定,得出4种草坪草种子抗酸雨胁迫能力由强到弱的顺序依次为高羊茅、黑麦草、匍匐剪股颖、狗牙根.%The seeds of Lolium perenne, Festuca arundinacea, Agrostis palustris and Cynodon dactylon were treated with simulated acid rain at pH 2.0,2.5,3.0,3.5,4. 0,5.0 and 7. 0(as control) to study the effects of acid rain on their germination. The results showed that the seeds germination of four turf grass under acid rain stress were affected at different levels. Acid rain intensity pH 2.0 completely inhibited the seed germination of turf grass, showing no germination was observed and germination energy and vigor index was 0.0. The seeds of L. Perenne and F. Arundinacea could germinate normally under acid rain stress (pH^2. 5) ,and the seeds of A. Paluslris could germinate normally under acid rain stress (pH^3.0).The seeds of C. Dactylon germinated poorly under acid rain stress. In addition, the process of germination became slow under acid rain stress. The comprehensive evaluation results derived from principal components analysis and subordinate function analysis showed the order (from strong to weak) of anti-acid rain ability

  10. Peanut cake concentrations in massai grass silage

    Directory of Open Access Journals (Sweden)

    Luciano S. Lima

    2013-03-01

    Full Text Available Objective. This experiment was conducted to evaluate the best concentration of peanut cake in the ensiling of massai grass of the chemical-bromatological composition, fermentative characteristics, forage value rate, ingestion estimates, and digestibility of dry matter in the silage. Materials and methods. The experiment was carried out at the Experimental Farm of São Gonçalo dos Campos at the Federal University of Bahia, Brazil. The treatments consisted of massai grass that was cut at 40 days and dehydrated, in addition to 0%, 8%, 16%, and 24% peanut cake in the fresh matter and treatment without cake. The material was compressed in experimental silos (7 liter that were opened after 76 days. Results. The addition of 8-24% peanut cake improved the silage’s chemical-bromatological parameters, increased the dry matter and non-fiber carbohydrates and reduced the fibrous components. There was a linear increase in the estimated values of digestibility and the ingestion of dry matter depending on the levels of peanut cake in the silage. There was an improvement in the fermentative characteristics, with a quadratic effect positive for levels of ammoniacal nitrogen. The forage value rate increased linearly with the inclusion of peanut cake. Conclusions. The inclusion of up to 24% peanut cake during ensiling of massai grass increases the nutritive value of silage and improves fermentation characteristics.

  11. Stable Carbon Isotope Ratios of Individual Pollen Grains as a Proxy for C3- Versus C4-Grass Abundance in Paleorecords: A Validation Study

    Science.gov (United States)

    Nelson, D. M.; Hu, F.; Pearson, A.

    2007-12-01

    distinguishing C3 and C4 shifts. At 9 of the 10 sites C/N values indicate that surface-sediment organic matter was derived primarily from aquatic production. At the one site where organic matter was produced primarily by vascular plants the δ13C value (-29.3°) suggests organic matter derived exclusively from C3 plants. However, ~80% of the grasses on the landscape at this site are C4 grasses. The C3- like bulk-sediment δ13C value likely represents woody species, which comprise >90% of the pollen spectra. Thus δ13C analysis of single grains of grass pollen offers a new tool to classify grass pollen into two major functional groups and promises to advance our understanding of grassland ecology and evolution. Reference Nelson, D.M., Hu, F.S., Mikucki, J., Tian, J., and Pearson, A., 2007, Carbon isotopic analysis of individual pollen grains from C3 and C4 grasses using a spooling wire microcombustion interface: Geochimica et Cosmochimica Acta, v. 71, p. 4005-4014.

  12. Upgrading food wastes by means of bromelain and papain to enhance growth and immunity of grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Choi, W M; Lam, C L; Mo, W Y; Wong, M H

    2016-04-01

    The fast growing of global aquaculture industry accompanied with increasing pressure on the supply and price of traditional feed materials (e.g., fish meal and soy bean meal). This circumstance has urged the need to search alternative sources of feed stuff. Food waste was used as feed stuff in rearing fish which possess substantial protein and lipid. Grass carp are major species reared in Hong Kong with lower nutritional requirements; it is also an ideal species for investigating the feasibility of using food waste as fish feeds for local aquaculture industry. The growth and immunity, reflected by total protein, total immunologlobulin (IgI), and nitroblue tetrazolium (NBT) activity of grass carp blood, were depressed when feeding with food waste feeds without enzymes. However, the supplementation of bromelain and papain in fish feed enhanced the efficient use of food waste by grass carp, which in turn improved the fish immunity. The present results indicated that the addition of those enzymes could enhance the feed utilization by fish and hematological parameters of grass carp, and the improvement on growth and immunity superior to the control (commercial feed) was observed with the addition of bromelain and papain supplement. Addition of 1 and 2 % mixture of bromelain and papain could significantly enhance the lipid utilization in grass carp. PMID:26092357

  13. Tolerance of Grasses to Heavy Metals and Microbial Functional Diversity in Soils Contaminated with Copper Mine Tailings

    Institute of Scientific and Technical Information of China (English)

    TENG Ying; LUO Yong-Ming; HUANG Chang-Yong; LONG Jian; LI Zhen-Gao; P.CHRISTIE

    2008-01-01

    Copper (Cu) mine tallings,because of their high content of heavy metals,are usually hostile to plant colonization.A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China.All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture.However,on pure mine tailings,the growth was minimal,whereas the growth was maximum for the control without mine railings.The tolerance of grasses to heavy metals followed the sequence: Paspalum notatum >Festuca arundinacea >Lolium perenne >Cynodon dactylon.The planting of forage grasses enhanced the soil microbial biomass.The Biolog data indicated that the soil microbial metabolic profile values (average well color development,community richness,and Shannon index) of the four forage grasses also followed the sequence: P.notatum > F.arundinacea > L.perenne > C.dactylon.Thus,P.notatum,under the experimental conditions of this study,may be considered as the preferred plant species for revegetation of Cu mine tailing areas.

  14. In situ Shear Tests of Soil Samples with Grass Roots in Alpine Environment

    Directory of Open Access Journals (Sweden)

    E. Comino

    2009-01-01

    Full Text Available Problem statement: The presence of vegetation increases the soil burden stability along slopes and reduces soil erosion. Its contribution is due to mechanical (reinforcing soil shear resistance and hydrologic controls on streambank and superficial landslides. This study presented the results carried out from experimental in situ test focused to study the increased shear resistance of soil blocks due to root-reinforcement. A shear apparatus was set up in order to realize the measure. Approach: In this research the researchers tested the capacity root reinforcement of Festuca pratensis, Lolium perenne and Poa pratensis (Poaceae families, Medicago sativa, Trifolium pratensis and Lotus corniculatus (Fabaceae families grass species widespread in the Alpine environment. Results: In situ shear tests results revealed that grass roots fail progressively and their tendency were to slip, without failing. Shear-strengths calculated for root-reinforced soil with Fabaceae, yielded values between 19 and 166% higher than directly measured shear-strengths in soil with no roots. The shear displacement had an increase included between 493 and 1.900%. The shear time was always superior. The clod with roots, after the trials, were always packed together. Conclusion: These data were lower than those obtained with Poaceae tests (from 50-318%, but the two grass families were functional for a grass mix useful in technical seeding.

  15. Natural recruitment contributes to high densities of grass carp Ctenopharyngodon idella (Valenciennes, 1844) in Western Europe

    OpenAIRE

    Milardi, Marco; Lanzoni, Mattia; Kiljunen, Mikko; Torniainen, Jyrki; Castaldelli, Giuseppe

    2015-01-01

    Introductions of grass carp, well known for their potentially negative ecosystem effects, have been performed in several countries around the world. As the species was considered unable to reproduce naturally under non-native environmental conditions, little attention was initially given to its invasive potential. We studied an area in northern-Italy where, contrary to expectations, introductions that were performed in the early 80s still exert a considerable pressure on aquatic macr...

  16. Body Size Correlates with Fertilization Success but not Gonad Size in Grass Goby Territorial Males

    OpenAIRE

    Jose Martin Pujolar; Lisa Locatello; Lorenzo Zane; Carlotta Mazzoldi

    2012-01-01

    In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a hig...

  17. Production and nitrogen uptake of grasses on different shading and fertilization

    OpenAIRE

    J Sirait; N.D Purwantari; K. Simanihuruk

    2005-01-01

    An experiment was conducted in Indonesian Research Institute for Animal Production (IRIAP) Bogor, West Java. The objective of this research was to study the production and nitrogen uptake of three short grasses species for grazing namely Paspalum notatum, Brachiaria humidicola, Stenotaphrum secundatum on different shading and fertilization. This experiment was arranged in split-split plot design. The main plot was shading level (0, 38, and 56%); sub-plot was fertilizer dosage (0, 100, and 200...

  18. Obsessed with grasses?: The case of mara Dolichotis patagonum(Caviidae: Rodentia) ¿Obsesionada con gramíneas?: El caso de mara Dolichotis patagonum (Caviidae: Rodentia)

    OpenAIRE

    MOIRA S. SOMBRA; ANTONIO M MANGIONE

    2005-01-01

    The diet of mara (Dolichotis patagonum, Zimmeraman 1780) within the limits of Sierra de las Quijadas National Park (San Luis, Argentina) is described. Other studies regarding mara’s diet showed that mara, feeds on different species of grasses and shrubs. However, there is controversy regarding the proportions of these items in the diet or whether this proportion varies seasonally. Considering mara’s body size, anatomical features and physiology, we suggest that mara feeds on grasses in a grea...

  19. Infection of Brachypodium distachyon with selected grass rust pathogens.

    Science.gov (United States)

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens.

  20. Thorough Characterization of Brazilian New Generation of Eucalypt Clones and Grass for Pulp Production

    Directory of Open Access Journals (Sweden)

    Fernando José Borges Gomes

    2015-01-01

    Full Text Available Eucalypt wood is becoming the most important raw material for the pulp industries in South America. However, due to the high wood cost in comparison to other raw material sources, nonwoody materials are also being investigated aiming at pulp production. In this way, this paper aimed at the evaluation of eighteen eucalypt clones obtained from the Brazilian Genolyptus project, regarding their potential characteristics for pulp production. Aiming at the same goal, two species of elephant grass were also evaluated as alternative raw material sources. Through the analyses of the anatomic and chemical characteristics, five eucalypt clones and one elephant grass species were indicated for pulp production and biorefinery application. The results of this study indicate the high technological quality of Eucalyptus clones evaluated and indicate that they can be used for biorefinery applications since they have the suitable characteristics. In general, the eucalypt clones are less moist and denser and contain fewer minerals and extraneous materials than the elephant grass species, which make them more attractive for utilization in deconstruction studies aiming at production of bioproducts.

  1. Accuracy and Consistency of Grass Pollen Identification by Human Analysts Using Electron Micrographs of Surface Ornamentation

    Directory of Open Access Journals (Sweden)

    Luke Mander

    2014-08-01

    Full Text Available Premise of the study: Humans frequently identify pollen grains at a taxonomic rank above species. Grass pollen is a classic case of this situation, which has led to the development of computational methods for identifying grass pollen species. This paper aims to provide context for these computational methods by quantifying the accuracy and consistency of human identification. Methods: We measured the ability of nine human analysts to identify 12 species of grass pollen using scanning electron microscopy images. These are the same images that were used in computational identifications. We have measured the coverage, accuracy, and consistency of each analyst, and investigated their ability to recognize duplicate images. Results: Coverage ranged from 87.5% to 100%. Mean identification accuracy ranged from 46.67% to 87.5%. The identification consistency of each analyst ranged from 32.5% to 87.5%, and each of the nine analysts produced considerably different identification schemes. The proportion of duplicate image pairs that were missed ranged from 6.25% to 58.33%. Discussion: The identification errors made by each analyst, which result in a decline in accuracy and consistency, are likely related to psychological factors such as the limited capacity of human memory, fatigue and boredom, recency effects, and positivity bias.

  2. Mass spectrometric investigation of molecular variability of grass pollen group 1 allergens.

    Science.gov (United States)

    Fenaille, François; Nony, Emmanuel; Chabre, Henri; Lautrette, Aurélie; Couret, Marie-Noëlle; Batard, Thierry; Moingeon, Philippe; Ezan, Eric

    2009-08-01

    Natural grass pollen allergens exhibit a wide variety of isoforms. Precise characterization of such microheterogeneity is essential to improve diagnosis and design appropriate immunotherapies. Moreover, standardization of allergen vaccine production is a prerequisite for product safety and efficiency. Both qualitative and quantitative analytical methods are thus required to monitor and control the huge natural variability of pollens, as well as final product quality. A proteomic approach has been set up to investigate in depth the structural variability of five group 1 allergens originating from distinct grass species (Ant o 1, Dac g 1, Lol p 1, Phl p 1, and Poa p 1). Whereas group 1 is the most conserved grass pollen allergen, great variations were shown between the various isoforms found in these five species using mass spectrometry, with many amino acid exchanges, as well as variations in proline hydroxylation level and in main N-glycan motifs. The presence of O-linked pentose residues was also demonstrated, with up to three consecutive units on the first hydroxyproline of Ant o 1. In addition, species-specific peptides were identified that might be used for product authentication or individual allergen quantification. Lastly, natural or process-induced modifications (deamidation, oxidation, glycation) were evidenced, which might constitute useful indicators of product degradation. PMID:19572759

  3. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures

    Science.gov (United States)

    Previous research indicates that photosynthetic metabolism of warm- and cool-season grass species affects greenhouse gas (GHG, (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O))) emissions from soil. This information could help establish best management practices to mitigate GHGs and stor...

  4. Detrimental and neutral effects of a wild grass-fungal endophyte symbiotum on insect preference and performance

    Science.gov (United States)

    The presence of seed-borne Epichloë/Neotyphodium (Ascomycota: Clavicipitaceae) fungal endophytes in temperate grasses can influence the outcome of grass–insect interactions. For example, the expression of endophyte-mediated resistance to insects depends on the insect species involved. The behavior...

  5. Presence of Trifolium repens promotes complementarity of water use and N facilitation in diverse grass mixtures

    Directory of Open Access Journals (Sweden)

    Pauline eHernandez

    2016-04-01

    Full Text Available Legume species promote productivity and increase the digestibility of herbage in grasslands. Considerable experimental data also indicate that communities with legumes produce more above-ground biomass than is expected from monocultures. While it has been attributed to N facilitation, evidence to identify the mechanisms involved is still lacking and the role of complementarity in soil water acquisition by vertical root differentiation remains unclear. We used a 20-month mesocosm experiment to investigate the effects of species richness (single species, two- and five-species mixtures and functional diversity (presence of the legume Trifolium repens on a set of traits related to light, N and water use and measured at community level. We found a positive effect of Trifolium presence and abundance on biomass production and complementarity effects in the two-species mixtures from the second year. In addition the community traits related to water and N acquisition and use (leaf area, N, water-use efficiency and deep root growth were higher in the presence of Trifolium. With a multiple regression approach, we showed that the traits related to water acquisition and use were with N the main determinants of biomass production and complementarity effects in diverse mixtures. At shallow soil layers, lower root mass of Trifolium and higher soil moisture should increase soil water availability for the associated grass species. Conversely at deep soil layer, higher root growth and lower soil moisture mirror soil resource use increase of mixtures. Altogether, these results highlight N facilitation but almost soil vertical differentiation and thus complementarity for water acquisition and use in mixtures with Trifolium. Contrary to grass-Trifolium mixtures, no significant over-yielding was measured for grass mixtures even those having complementary traits (short and shallow vs tall and deep. Thus, vertical complementarity for soil resources uptake in mixtures

  6. Presence of Trifolium repens Promotes Complementarity of Water Use and N Facilitation in Diverse Grass Mixtures.

    Science.gov (United States)

    Hernandez, Pauline; Picon-Cochard, Catherine

    2016-01-01

    Legume species promote productivity and increase the digestibility of herbage in grasslands. Considerable experimental data also indicate that communities with legumes produce more above-ground biomass than is expected from monocultures. While it has been attributed to N facilitation, evidence to identify the mechanisms involved is still lacking and the role of complementarity in soil water acquisition by vertical root differentiation remains unclear. We used a 20-months mesocosm experiment to investigate the effects of species richness (single species, two- and five-species mixtures) and functional diversity (presence of the legume Trifolium repens) on a set of traits related to light, N and water use and measured at community level. We found a positive effect of Trifolium presence and abundance on biomass production and complementarity effects in the two-species mixtures from the second year. In addition the community traits related to water and N acquisition and use (leaf area, N, water-use efficiency, and deep root growth) were higher in the presence of Trifolium. With a multiple regression approach, we showed that the traits related to water acquisition and use were with N the main determinants of biomass production and complementarity effects in diverse mixtures. At shallow soil layers, lower root mass of Trifolium and higher soil moisture should increase soil water availability for the associated grass species. Conversely at deep soil layer, higher root growth and lower soil moisture mirror soil resource use increase of mixtures. Altogether, these results highlight N facilitation but almost soil vertical differentiation and thus complementarity for water acquisition and use in mixtures with Trifolium. Contrary to grass-Trifolium mixtures, no significant over-yielding was measured for grass mixtures even those having complementary traits (short and shallow vs. tall and deep). Thus, vertical complementarity for soil resources uptake in mixtures was not only

  7. Ensiling as pretreatment of grass for lignocellulosic biomass conversion

    DEFF Research Database (Denmark)

    Ambye-Jensen, Morten

    an efficient production of ethanol. Lastly, the conversion of xylan was extremely low in both grass and grass silage. Optimization of the enzymatic saccharification of grass was attempted through improvement of the hemicellulase content in the enzyme blend. However, neither additional xylanases (Cellic HTec2......® and ß-xylosidase) nor hemicellulose degrading esterases (acetyl xylan esterase and ferulic acid esterase) showed any improvements of xylan or glucan convertibility. Furthermore, hemicellulases were added before ensiling in order to assist and improve the pretreatment effect. This resulted in, however.......3. Furthermore, the HTT pretreatment of both grass and grass silage gave considerably lower xylan convertibility than HTT of wheat straw and wheat straw silage. The reason for the inaccessible xylan in grass is believed to be found in a high complexity of branching and cross linkages creating a heterogeneous...

  8. How does altered precipitation and annual grass invasion affect plant N uptake in a native semi-arid shrub community?

    Science.gov (United States)

    Mauritz, M.; Lipson, D.; Cleland, E. E.

    2012-12-01

    Climate change is expected to alter precipitation patterns, which will change the timing and amount of plant resources. Precipitation patterns determine water and nitrogen (N) availability, because water stimulates microbial N turnover and N transport. In order for plants to utilize water and N, they must coincide with the phenology and meet physiological requirements of the plant. As resource supply shifts, differences in species' ability to acquire resources will affect plant community composition. Semiarid ecosystems, such as shrublands in Southern California, are particularly sensitive to shifts in precipitation because they are severely water limited. This study takes advantage of the altered phenology and resource demands presented by invasive annual grasses in a native semiarid shrubland. The goal is to understand how altered precipitation patterns affect plant N uptake. Rainfall levels were manipulated to 50% and 150% of ambient levels. It is expected that higher rainfall levels promote annual grass invasion because grasses have higher water and N requirements and begin to grow earlier in the season than shrubs. A 15N tracer was added with the first rain event and plant samples were collected regularly to track the movement of N into the plants. Net soil N accumulation was determined using resin bags. Invasive grasses altered the timing and amount of N uptake but amount of rainfall had less effect on N distribution. 15N was detected sooner and at higher level in grasses than shrubs. 24hours after the first rain event 15N was detectable in grasses, 15N accumulated rapidly and peaked 2 months earlier than shrubs. Shrub 15N levels remained at pre-rain event levels for the first 2 months and began to increase at the beginning of spring, peak mid-spring and decline as the shrubs entered summer dormancy. One year later 15N levels in annual grass litter remained high, while 15N levels in shrubs returned to initial background levels as a result of resorption. 15N

  9. C-isotope composition of fossil sedges and grasses

    Science.gov (United States)

    Kurschner, Wolfram M.

    2010-05-01

    C4 plants differ from C3 plants regarding their anatomy and their C-isotope composition. Both features can be used in the geological record to determine the presence of C4 plants. Yet, the evolution of the C4 pathway in the fossil record is enigmatic as palaeobotanical and geological evidence for C4 plants is sparse. The oldest structural evidence for Kranz anatomy has been found in Late Miocene permineralized grass leaf remains. But studies on the C-isotope composition of sedimentary organic matter indicate that abundant C4 biomass was present in N-America and Asia throughout the Miocene in expanding savannahs and grasslands. The success of C4 plants appears to be related also to an increasing seasonal aridity in the tropical climate belts and the co-evolution of grazers. However, C- isotope composition of palaeosols or vertebrate teeth only allows to estimate the abundance of C4 plant biomass in the vegetation or in the diet without further taxonomical specification which plant groups would have had C4 metabolism. In this contribution the first extensive C-isotope analysis of fossil seeds of sedges and a few grasses are presented. The age of the carpological material ranges from Late Eocene to Pliocene and was collected from several central European brown coal deposits. The 52 different taxa studied include several species of Carex, Cladiocarya, Eriopherum, Eleocharis, Scirpus, Sparganium. Most of them representing herbaceous elements of a (sub)tropical vegetation growing near the edge of a lake. The C-isotope composition of the fossil seeds varies between -30 and -23 o/oo indicating C3 photosynthesis. This first systematic inventory shows that C4 plants were absent in the European (sub)tropical brown coal forming wetland vegetation during the Tertiary. These preliminary data are in agreement with phylogenetic studies which predict the origin of C4 plants outside the European realm.

  10. Determining the regional potential for a grass biomethane industry

    International Nuclear Information System (INIS)

    Research highlights: → We identified assessment criteria for determining the regional potential for grass biomethane. → Grass biomethane is distributed via the natural gas grid. → The criteria include: land use; grass yields; gas grid coverage; availability of co-substrates. → The county with the highest potential can fuel 50% of cars or supply 130% of domestic gas consumption. - Abstract: Grass biogas/biomethane has been put forward as a renewable energy solution and it has been shown to perform well in terms of energy balance, greenhouse gas emissions and policy constraints. Biofuel and energy crop solutions are country-specific and grass biomethane has strong potential in countries with temperate climates and a high proportion of grassland, such as Ireland. For a grass biomethane industry to develop in a country, suitable regions (i.e. those with the highest potential) must be identified. In this paper, factors specifically related to the assessment of the potential of a grass biogas/biomethane industry are identified and analysed. The potential for grass biogas and grass biomethane is determined on a county-by-county basis using multi-criteria decision analysis. Values are assigned to each county and ratings and weightings applied to determine the overall county potential. The potential for grass biomethane with co-digestion of slaughter waste (belly grass) is also determined. The county with the highest potential (Limerick) is analysed in detail and is shown to have ready potential for production of gaseous biofuel to meet either 50% of the vehicle fleet or 130% of the domestic natural gas demand, through 25 facilities at a scale of ca. 30 kt yr-1 of feedstock. The assessment factors developed in this paper can be used in other resource studies into grass biomethane or other energy crops.

  11. Projected carbon dioxide to increase grass pollen and allergen exposure despite higher ozone levels.

    Directory of Open Access Journals (Sweden)

    Jennifer M Albertine

    Full Text Available One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10-30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2, a growth and reproductive stimulator of plants, and ozone (O3, a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.. We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change.

  12. Molecular cloning, characterization and expression of cathepsin D from grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Dong, Zhong-dian; Zhang, Jiao; Ji, Xiang-shan; Zhou, Fen-na; Fu, Yong; Chen, Weiyun; Zeng, Yong-qing; Li, Tong-ming; Wang, Hui

    2012-11-01

    Cathepsin D is a lysosomal aspartic proteinase which participates in various degradation functions within the cell. In this current study, we cloned and characterized the complete cDNA of grass carp cathepsin D through 5'- and 3'-RACE. The cathepsin D contained a 56 bp 5' terminal untranslated region (5'-UTR), a 1197 bp open reading frame encoding 398 amino acids, and a 394 bp 3'-UTR. Grass carp cathepsin D shared high similarity with those from other species, and showed the highest amino acid identity of 91% to Danio rerio. Unlike many other organisms, the grass carp cathepsin D contains only one N-glycosylation site closest to the N-terminal. Real-time quantitative RT-PCR demonstrated that Cathepsin D expressed in all twelve tissues (bladder, brain, liver, heart, gill, muscle, fin, eye, intestines, spleen, gonad and head kidney). The relative expression levels of Cathepsin D in gonad and liver were 26.58 and 24.95 times as much as those in fin, respectively. The expression level of Cathepsin D in muscle approximately 16-fold higher, in intestines and spleen were 12-fold higher. The cathepsin D expression showed an upward trend during embryonic development. After challenged with Aeromonas hydrophil, the expression of grass carp cathepsin D gene showed significant changes in the four test tissues (liver, head kidney, spleen and intestines). The fact that the bacterial infection can obviously improve the cathepsin D expression in immune-related organs, may suggest that cathepsin D plays an important role in the innate immune response of grass carp.

  13. Investigation of Desso GrassMaster® as application in hydraulic engineering

    NARCIS (Netherlands)

    Steeg, van der P.; Paulissen, M.P.C.P.; Roex, E.; Mommer, L.

    2015-01-01

    Dessa GrassMaster® is a reinforced grass system which is applied successfully on sports fields and enables to use a sports field more intensively than a normal grass field. In this report the possibility of an application of Dessa GrassMaster®in hydraulic conditions, with a focus on grass dikes, is

  14. Towards reconstructing herbaceous biome dynamics and associated precipitation in Africa: insights from the classification of grass morphological traits

    Science.gov (United States)

    Pasturel, Marine; Alexandre, Anne; Novello, Alice; Moctar Dieye, Amadou; Wele, Abdoulaye; Paradis, Laure; Hely, Christelle

    2014-05-01

    Inter-tropical herbaceous ecosystems occupy a 1/5th of terrestrial surface, a half of the African continent, and are expected to extend in the next decades. Dynamic of these ecosystems is simulated with poor accuracy by Dynamic Global Vegetation Models (DGVMs). One of the bias results from the fact that the diversity of the grass layer dominating these herbaceous ecosystems is poorly taken into account. Mean annual precipitation and the length of the dry season are the main constrains of the dynamics of these ecosystems. Conversely, changes in vegetation affect the water cycle. Inaccuracy in herbaceous ecosystem simulation thus impacts simulations of the water cycle (including precipitation) and vice versa. In order to increase our knowledge of the relationships between grass morphological traits, taxonomy, biomes and climatic niches in Western and South Africa, a 3-step methodology was followed: i) values of culm height, leaf length and width of dominant grass species from Senegal were gathered from flora and clustered using the Partition Around Medoids (PAM) method; ii) trait group ability to sign climatic domains and biomes was assessed using Kruskal-Wallis tests; iii) genericity and robustness of the trait groups were evaluated through their application to Chadian and South African botanical datasets. Results show that 8 grass trait groups are present either in Senegal, Chad or South Africa. These 8 trait groups are distributed along mean annual precipitation and dry season length gradients. The combination of three of them allow to discriminate mean annual precipitation domains (1000 mm) and herbaceous biomes (steppes, savannas, South African grasslands and Nama-Karoo). With these results in hand, grass Plant Functional Types (PFTs) of the DGMV LPJ-GUESS will be re-parameterized and particular attention will be given to the herbaceous biomass assigned to each grass trait group. Simultaneously, relationships between grass trait groups and phytolith vegetation

  15. Effects of ungulates and prairie dogs on seed banks and vegetation in a North American mixed-grass prairie

    Science.gov (United States)

    Fahnestock, J.T.; Larson, D.L.; Plumb, G.E.; Detling, J.K.

    2003-01-01

    The relationship between vegetation cover and soil seed banks was studied in five different ungulate herbivoreprairie dog treatment combinations at three northern mixed-grass prairie sites in Badlands National Park, South Dakota. There were distinct differences in both the seed bank composition and the aboveground vegetation between the off-prairie dog colony treatments and the on-colony treatments. The three on-colony treatments were similar to each other at all three sites with vegetation dominated by the forbs Dyssodia papposa, Hedeoma spp., Sphaeralcea coccinea, Conyza canadensis, and Plantago patagonica and seed banks dominated by the forbs Verbena bracteata and Dyssodia papposa. The two off-colony treatments were also similar to each other at all three sites. Vegetation at these sites was dominated by the grasses Pascopyrum smithii, Bromus tectorum and Bouteloua gracilis and the seed banks were dominated by several grasses including Bromus tectorum, Monroa squarrosa, Panicum capillare, Sporobolus cryptandra and Stipa viridula. A total of 146 seedlings representing 21 species germinated and emerged from off-colony treatments while 3069 seedlings comprising 33 species germinated from on-colony treatments. Fifteen of the forty species found in soil seed banks were not present in the vegetation, and 57 of the 82 species represented in the vegetation were not found in the seed banks. Few dominant species typical of mixed-grass prairie vegetation germinated and emerged from seed banks collected from prairie dog colony treatments suggesting that removal of prairie dogs will not result in the rapid reestablishment of representative mixed-grass prairie unless steps are taken to restore the soil seed bank.

  16. Upgrated fuel from reed canary grass

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    Results described in this presentation are from a large EU-project - Development of a new crop production system based on delayed harvesting and system for its combined processing to chemical pulp and biofuel powder. This is a project to develop the use of Reed Canary Grass (Phalaris Arundinaceae) both for pulp industry and energy production. The main contractor of the project is Swedish University of Agricultural Sciences (coordinator), task coordinators are United Milling Systems A/S from Denmark, and Jaakko Poeyry Oy and VTT Energy from Finland In addition, there are partners from several countries participating in the project

  17. Effects of Neotyphodium endophytes on seed germination of three grass species under different pH conditions%不同酸碱条件下内生真菌对三种禾草种子萌发的影响

    Institute of Scientific and Technical Information of China (English)

    彭清青; 李春杰; 宋梅玲; 梁莹; 南志标

    2011-01-01

    Neotyphodium endophytes may improve host grass competitive abilities by increasing seed germina tion success and enhancing host plant growth under water stress, salt and other environmental stress condi tions. To find if there were differences in germination between Neotyphodium endophyte infected (E+) and uninfected (E-) plants of three grass species (Achnatherum inebrians, Festuca sinensis and Hordeum bre visubulatum), eight pH levels (pH 4-11) were used. The results indicated that the germination energy of E+ A. inebrians seed were much higher than those of E- seed at pH 6 -11 (P<0. 05); the germination rate was significantly higher at pH 4 - 5; the shoot and radical growth of E+ were higher than those of E-, especially at pH 7 - 11 (P<0. 05); and there was much higher dry weight at pH 4 - 7. The percentage of abnormal ger mination of E+ seed at pH 4 and at pH 11 was significantly (P<0. 05) lower than that of E- seed. Similarly, E+ F. sinensis seed performed much better than E- seed in germination rate, germination energy, radical growth, shoot growth and dry weight. There were significant differences in germination energy at pH 6 - 10 (P<0. 05), germination rate at pH 4 and pH 8-11 (P<0. 05), shoot growth at pH 4 -11 (P<0. 05), radical growth at pH 10 (P<0. 05), and the dry weight of E+ seedlings was significantly greater at pH 4 - 6 (P< 0. 05). The percentage of abnormal germination was highest at pH 11 (P<0. 05). Compared with E- H. bre visubulatum, E+ seed had greater germination energy at pH 4 -11 (P<0. 05); the shoot and radical growth were significantly greater than those of E- seedlings at pH 9 - 11 and pH 8 - 11 (P<0. 05) as was the dry weight at pH 4 -11 (P<0. 05). The percentage of abnormal germination of E+ seed was significantly less than that of E- seed at pH 4. Overall, the optimal pH value for A. inebrians was 6 - 9; for F. sinensis was 6 - 7, and for H. brevisubulatum was 7 - 9.%内生真菌可以通过提高禾草种子在干旱、盐胁迫等

  18. Treatment of grass pollen allergy: focus on a standardized grass allergen extract – Grazax®

    Directory of Open Access Journals (Sweden)

    Moisés Calderón

    2008-11-01

    Full Text Available Moisés Calderón1, Tove Brandt21Section of Allergy and Clinical Immunology, Royal Brompton Hospital, Imperial College, NHLI, London, UK; 2Group Clinical Development, ALK-Abelló A/S, Hørsholm, DenmarkAbstract: Immunotherapy is the only treatment for allergy that has the potential to alter the natural course of the disease. Sublingual immunotherapy (SLIT for grass pollen-induced rhino-conjunctivitis has been developed to make immunotherapy available to a broader group of allergic patients. In the largest clinical programme ever conducted with allergen-specific immunotherapy, over 1,700 adults and 260 children have been exposed to Grazax®. Grazax is formulated as an oral lyophilisate (tablet for sublingual administration, containing 75,000 SQ-T standardized allergen extract of grass pollen from Phleum pratense. Grazax is indicated for treatment of grass pollen-induced rhinitis and conjunctivitis in adult patients with clinically relevant symptoms and diagnosed with a positive skin prick test and/or specific IgE test to grass pollen. In phase I trials doses from 2,500 to 1,000,000 SQ-T were tested. All doses were well tolerated and 75,000 SQ-T, with approximately 15 µg major allergen protein, was chosen as the optimal dose. Three phase III trials are ongoing, one being a long-term trial. Results from GT-08 trial first and second treatment years showed a reduction of 30% and 36%, respectively, in daily rhino-conjunctivitis symptom scores and a reduction of 38% and 46% of daily rhinoconjunctivitis medication scores compared with placebo over the entire grass pollen season. Subjects treated with Grazax also had an increased number of well days and improved quality of life, and more subjects experienced excellent rhino-conjunctivitis control. The most common adverse events related to Grazax are local reactions, such as pruritus, edema mouth, ear pruritus, throat irritation, and sneezing. We conclude that Grazax is efficacious and safe for treatment

  19. GWN-3189 B – A new selective herbicide based on Triallate for control of herbicide resistant grass weed in cereals

    Directory of Open Access Journals (Sweden)

    Mühlschlegel, Friedrich

    2014-02-01

    Full Text Available With substantial work on the formulation, Gowan offers a new herbicide (GWN-3189 B based on Triallate for use on winter wheat, winter barley, winter rye, winter triticale and spring barley. GWN-3189B will be applied from pre-emergence to early post-emergence of the crop and offers a broad spectrum against grass-weeds. GWN-3189 B is selective on all cereal species. As soil herbicide GWN-3189 B offers interesting alternatives in grass-weed resistance management. The efficacy on grass weed, especially on Alopecurus myosuroides (blackgrass, Apera spica venti (silky bentgrass and Lolium multiflorum (italian ryegrass is demonstrated with results of field trials performed in France, Great Britain and Germany.

  20. Storage of carbon in natural grasses high andean

    Directory of Open Access Journals (Sweden)

    Raúl Marino Yaranga Cano

    2013-12-01

    Full Text Available The aim of the study was to determine the capacity of storage of carbon in species of grasses natural of high andean, between January of 2012 and March of 2013. They were defined two sampling areas in the districts of Huasicancha and Chicche of the county of Huancayo, Junín. The first of the areas was located in the place Pumahuasi (18L 466456E 8628580N and the second in Vista Alegre (18L 464886E 8642964N, between 3 845 and 3 870 meters of altitude. 10 plants per species were collected at random, between April and May, considering the moment of maximum growth of the plants. The samples were washed and dried off to the atmosphere during 15 days, being completed the drying in a stove to 60 °C, during 48 hours. The determination of the percentage of dry matter of the samples was carried out by the difference between the initial and final weights. While that the determination of the percentage of carbon was carried out through the method of Walkley-Black. The results of the correlation of weight between air biomass and biomass radicular were highly significant r = 0.9856 ** and b = 3.4507. The percentage of the weight of the root regarding that of the air biomass oscillated between 27.93% and 30.20%, respectively. The content of carbon expressed as percentage varied according to the part of the plant and the origin place.

  1. Intrapopulation sex ratio variation in the salt grass Distichlis spicata.

    Science.gov (United States)

    Eppley, S M; Stanton, M L; Grosberg, R K

    1998-11-01

    ABSTRACT In many dioecious plant populations, males and females appear to be spatially segregated, a pattern that is difficult to explain given its potentially high costs. However, in asexually propagating species, spatial segregation of the sexes may be indistinguishable from superficially similar patterns generated by random establishment of a few genets followed by extensive clonal spread and by gender-specific differences in rates of clonal spread. In populations where a significant fraction of individuals are not flowering and gender cannot be assigned to this fraction, apparent spatial segregation of the sexes may be due to differential flowering between the sexes. We confirm reports that flowering ramets of the clonal, perennial grass Distichlis spicata are spatially segregated by sex. We extend these studies in two fundamental ways and demonstrate that this species exhibits true spatial segregation of the sexes. First, using RAPD markers, we estimated that at least 50% of ramets in patches with biased sex ratios represent distinct genotypes. Second, we identified a RAPD marker linked to female phenotype (eliminating the possibility that gender is environmentally determined) and used it to show that the majority of patches exhibit significantly biased sex ratios for both ramets and genets, regardless of flowering status.

  2. Application of DNA (RAPD and ultrastructure to detect the effect of cadmium stress in Egyptian clover and Sudan grass plantlets

    Directory of Open Access Journals (Sweden)

    Amina A. Aly

    2012-04-01

    Full Text Available BackgroundIn recent years, several plant species have been used as bioindicators to evaluate the toxicity of environmental contaminants on vegetal organisms. In this study, Egyptian clover and Sudan grass seedlings were grown in four cadmium (Cd concentration levels (0.0, 25, 50 and 100 µM in MS media to analyze growth responses, Cd accumulation in the shoots and roots of plantlets, proline contents, chlorophylls content and MDA levels of both plantlets. As well as RAPD analysis and leaves ultrastructure were detected.ResultsThe results showed that there was a significant decrease in root and shoot lengths, Chl a, Chl b, total Chl and carotenoids contents for both Egyptian clover and Sudan grass. However, there was a significant increase in Cd accumulation, proline and malondialdehyde (MDA levels. The genetic variation between Egyptian clover and Sudan grass were evaluated using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR markers to establish specific DNA markers associated with Cd stress. The results of transimssion electron microscopy (TEM showed a clear disorder in the Cd treated Egyptian clover and Sudan grass seedlings.ConclusionIn conclusion, biochemical, molecular and ultrastructure changes in Egyptian clover and Sudan grass could be used as a useful biomarker assay for the detection of genotoxic effects of Cd stress on plants. However, it is necessary to be further confirmed and optimized in the future research.

  3. Potential of grasses and rhizosphere bacteria for bioremediation of diesel-contaminated soils

    Directory of Open Access Journals (Sweden)

    Melissa Paola Mezzari

    2011-12-01

    Full Text Available The techniques available for the remediation of environmental accidents involving petroleum hydrocarbons are generally high-cost solutions. A cheaper, practical and ecologically relevant alternative is the association of plants with microorganisms that contribute to the degradation and removal of hydrocarbons from the soil. The growth of three tropical grass species (Brachiaria brizantha, Brachiaria decumbens and Paspalum notatum and the survival of root-associated bacterial communities was evaluated at different diesel oil concentrations. Seeds of three grass species were germinated in greenhouse and at different doses of diesel (0, 2.5, 5 and 10 g kg-1 soil. Plants were grown for 10 weeks with periodic assessment of germination, growth (fresh and dry weight, height, and number of bacteria in the soil (pots with or without plants. Growth and biomass of B. decumbens and P. notatum declined significantly when planted in diesel-oil contaminated soils. The presence of diesel fuel did not affect the growth of B. brizantha, which was highly tolerant to this pollutant. Bacterial growth was significant (p < 0.05 and the increase was directly proportional to the diesel dose. Bacteria growth in diesel-contaminated soils was stimulated up to 5-fold by the presence of grasses, demonstrating the positive interactions between rhizosphere and hydrocarbon-degrading bacteria in the remediation of diesel-contaminated soils.

  4. Seedling emergence of tall fescue and wheat grass under different climate conditions in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Behtari, B.; Luis, M. de

    2012-11-01

    Seedling emergence is one of the most important processes determining yield and the probability of crop failure. The ability to predict seedling emergence could enhance crop management by facilitating the implementation of more effective weed control strategies by optimizing the timing of weed control. The objective of the study was to select a seedling emergence thermal time model by comparing five different equations for tall fescue and wheat grass in two sites with different climate conditions (semiarid-temperate and humid-warm) in Iran. In addition, seedling emergence between two target species were studied. Among the five models compared, the Gompertz and Weibull models gave more successful results. In humid-warm conditions, the total emergence of wheat grass was higher than observed in tall fescue. In contrast, emergence was faster in tall fescue than wheat grass in both study sites. Given that early-emerging plants have been described as contributing more to crop yield than later-emerging ones, tall fescue is proposed as a more suitable specie for semiarid- temperate conditions in Iran. (Author) 31 refs.

  5. Isolation and Identification of Epiphytic Lactic Acid Bacteria from Guinea Grass (Panicum maximum

    Directory of Open Access Journals (Sweden)

    M. Pasebani

    2010-01-01

    Full Text Available Problem statement: Bacteria can perform a variety of beneficial functions, for example many lactic acid bacteria are responsible for fermentation of silage in the process of forage conservation. In the making of silage, epiphytic lactic acid bacteria are usually insufficient in numbers to promote efficient lactate fermentation. This study was conducted to identify the predominant indigenous bacteria, with emphasis on lactic acid bacteria, from Guinea grass (Panicum maximum. Approach: Two different condition of growth using nutrient and MRS agar were prepared for isolation of the bacteria. In total, 18 purified isolates were identified by BIOLOG identification system which comprised of 9 bacterial species. Standard plate count in the both conditions was considered. Results: Three bacterial species based on the first condition of growth were identified which were belonging to Flavimonas oryzihabitans, Enerobacter cloacae, Sphingomonas paucimobilis B. Lactic acid bacteria based on the second condition of growth were belonging to Weissella confusa, Weissella paramesenteroides, Leuconostoc mesenteroides ssp. dextranicum, Lactococcus lactis ssp. hordniae. Result of plate count showed that 8.3×103 CFU lactic acid bacteria are available per gram of fresh guinea grass. Conclusion: Three hetero-fermentative and one homo-fermentative lactic acid bacteria were identified which would be suggested to use as bacterial inoculants because of the insufficient amount of epiphytic lactic acid bacteria and the availability of pathogenic bacteria in the grass.

  6. Vetiver Grass: a potential tool for phytoremediation of iron ore mine site spoil dump

    Directory of Open Access Journals (Sweden)

    Anita Mukherjee

    2015-06-01

    Full Text Available The impact of mining has lead to the generation of a large amount of spoil dumps that has become dangerous to human health, wildlife and biodiversity. Thus it is essential that the post mining areas and waste land generated need to be rapidly vegetated. Vetiver grass (Chrysopogon zizanioides (L. Roberty is a tropical plant which grows naturally in various soil conditions and is well known for its ability to resist DNA damage while growing on typically polluted soil conditions. The spoil dumps from the iron mine site is unstable and inhospitable for plant growth due to presence of various toxic heavy metals like - Fe, Mn, Zn, Cu, Pb, Ni, Cr, Cd etc. Vetiver system is an efficient bio-engineering tool for reclaiming such spoil dumps. There are 12 known species of Vetiver grass, and many hundreds of different cultivars that are exploited by users depending on need. In the present study we selected the polyploid infertile variety of vetiver and carried pot experiments. Vetiver plants grown on the iron ore mine spoil dump show distinct differences in their growth with fewer numbers of tillers, reduced chlorophyll content, upregulation of antioxidant enzymes and increased proline content. To investigate the level of DNA damage incurred and change in the genetic stability Comet assay and RAPD analysis were performed. Results confirmed that Vetiver grass can serve as a model species for phytoremediating the iron ore mine spoil dumps.

  7. A greenhouse study of grass response on composite tailings discharged from Alberta oil sands mine

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shihong; Wang, Bing [Klohn Crippen Berger Ltd (Canada); Sego, David [Department of Civil and Environmental Engineering, University of Alberta (Canada); Naeth, Anne [Department of Renewable Resources, University of Alberta (Canada)

    2011-07-01

    This study presents an evaluation of the survival and growth of five plant species directly seeded using hydro seeding with mulch, modified broadcast seeding and fresh discharged composite tailings (CT) slurry seeding techniques. The study discusses a greenhouse experiment on grass response that was conducted on composite tailings discharged from an Alberta oil sands mine. The five grass species: bluejoint (Calamagrostis canadensis), creeping red fescue (Festuca rubra), hairy wild rye (Elymus innovatus beal), northern wheatgrass (Agropyron dasystachyum) and slender wheatgrass (Agropyron trachycaulum) were selected for the study based on plant growth and site climatic conditions. The CT mixture was paced in a 4L plastic pail with no drainage at the bottom to prevent water loss. The experimental results indicated broadcast seeding and hydro seeding with mulch and discharge of CT slurry containing seeds can be applied for seeding grass on vast CT deposits. The results also showed a substantial benefit from dewatering CT as a first step towards sustainable development and environmental protection.

  8. Relationships between milk fatty acid profiles and enteric methane production in dairy cattle fed grass- or grass silage-based diets

    NARCIS (Netherlands)

    Dijkstra, J.; Gastelen, van S.; Antunes Fernandes, E.C.; Warner, D.; Hatew, Bayissa; Klop, G.; Podesta, S.C.; Lingen, van H.J.; Hettinga, K.A.; Bannink, A.

    2016-01-01

    We quantified relationships between methane production and milk fatty acid (FA) profile in dairy cattle fed grass- or grass silage-based diets, and determined whether recent prediction equations for methane, based on a wide variety of diets, are applicable to grass- and grass silage-based diets. Dat

  9. Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Steve A. [University of California San Diego

    2013-05-02

    Several breakthroughs have been recently made in our understanding of plant growth and biomass accumulation. It was found that plant growth is rhythmically controlled throughout the day by the circadian clock through a complex interplay of light and phytohormone signaling pathways. While plants such as the C4 energy crop sorghum (Sorghum bicolor (L.) Moench) and possibly the C3 grass (Brachypodium distachyon) also exhibit daily rhythms in growth rate, the molecular details of its regulation remain to be explored. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to future strategies to optimize energy crop biomass yield. Here we propose to devise a systems approach to identify, in parallel, regulatory hubs associated with rhythmic growth in C3 and C4 plants. We propose to use rhythmicity in daily growth patterns to drive the discovery of regulatory network modules controlling biomass accumulation.

  10. Tracking the evolution of a cold stress associated gene family in cold tolerant grasses

    DEFF Research Database (Denmark)

    Sandve, Simen R; Rudi, Heidi; Asp, Torben;

    2008-01-01

    Background Grasses are adapted to a wide range of climatic conditions. Species of the subfamily Pooideae, which includes wheat, barley and important forage grasses, have evolved extreme frost tolerance. A class of ice binding proteins that inhibit ice re-crystallisation, specific to the Pooideae...... subfamily lineage, have been identified in perennial ryegrass and wheat, and these proteins are thought to have evolved from a leucine-rich repeat phytosulfokine receptor kinase (LRR-PSR)-like ancestor gene. Even though the ice re-crystallisation inhibition function of these proteins has been studied...... extensively in vitro, little is known about the evolution of these genes on the molecular level. Results We identified 15 putative novel ice re-crystallisation inhibition (IRI)-like protein coding genes in perennial ryegrass, barley, and wheat. Using synonymous divergence estimates we reconstructed...

  11. A novel test for host-symbiont codivergence indicates ancient origin of fungal endophytes in grasses

    CERN Document Server

    Schardl, Chris L; Lindstrom, Adam; Speakman, Skyler; Stromberg, Arnold; Yoshida, Ruriko

    2007-01-01

    Significant phylogenetic codivergence between plant or animal hosts ($H$) and their symbionts or parasites ($P$) indicate the importance of their interactions on evolutionary time scales. However, valid and realistic methods to test for codivergence are not fully developed. One of the systems where possible codivergence has been of interest involves the large subfamily of temperate grasses (Pooideae) and their endophytic fungi (epichloae). These widespread symbioses often help protect host plants from herbivory and stresses, and affect species diversity and food web structures. Here we introduce the MRCALink (most-recent-common-ancestor link) method and use it to investigate the possibility of grass-epichlo\\"e codivergence. MRCALink applied to ultrametric $H$ and $P$ trees identifies all corresponding nodes for pairwise comparisons of MRCA ages. The result is compared to the space of random $H$ and $P$ tree pairs estimated by a Monte Carlo method.

  12. Sunflower meal concentrations in Massai grass silage

    Directory of Open Access Journals (Sweden)

    Máikal S. Borja

    2012-08-01

    Full Text Available Objetive. This experiment was conducted to evaluate the best sunflower meal concentration in Massai grass silage. Materials and methods. The treatments were composed of 0, 8, 16, and 24% sunflower meal (natural matter basis during ensiling of Massai grass, with four repetitions. Results. The regression equation showed that the inclusion of sunflower meal between 2.14% and 13.91% obtained a silage dry matter between 25 and 35%, which are the values recommended for the production of high quality silage. The addition of sunflower meal showed a linear increase in crude protein, reaching 18% DM with the highest concentration of sunflower meal. The highest feed value index was obtained with the addition of 24% sunflower meal in the silage. The estimated total digestible nutrient of silage increased linearly with sunflower meal concentration. The silage pH values had a quadratic effect, reaching the lowest value (4.1 with 15% sunflower meal addition. Conclusions. Based on the chemical composition and forage quality, a concentration of 14% sunflower meal should be used for high-quality silage with good nutritional value.

  13. Elephant grass clones for silage production

    Directory of Open Access Journals (Sweden)

    Rerisson José Cipriano dos Santos

    2013-02-01

    Full Text Available Ensiling warm-season grasses often requires wilting due to their high moisture content, and the presence of low-soluble sugars in these grasses usually demands the use of additives during the ensiling process. This study evaluated the bromatological composition of the fodder and silage from five Pennisetum sp. clones (IPA HV 241, IPA/UFRPE Taiwan A-146 2.114, IPA/UFRPE Taiwan A-146 2.37, Elephant B, and Mott. The contents of 20 Polyvinyl chloride (PVC silos, which were opened after 90 days of storage, were used for the bromatological analysis and the evaluation of the pH, nitrogen, ammonia, buffer capacity, soluble carbohydrates, and fermentation coefficients. The effluent losses, gases and dry matter recovery were also calculated. Although differences were observed among the clones (p < 0.05 for the concentrations of dry matter, insoluble nitrogen in acid detergents, insoluble nitrogen in neutral detergents, soluble carbohydrates, fermentation coefficients, and in vitro digestibility in the forage before ensiling, no differences were observed for most of these variables after ensiling. All of the clones were efficient in the fermentation process. The IPA/UFRPE TAIWAN A-146 2.37 clone, however, presented a higher dry matter concentration and the best fermentation coefficient, resulting in a better silage quality, compared to the other clones.

  14. Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration

    Science.gov (United States)

    Yurkonis, Kathryn A.; Wilsey, Brian J.; Moloney, Kirk A.; Drobney, Pauline; Larson, Diane L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat-scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine-scale seed distribution. However, native warm-season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine-scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands.

  15. Fatty acid composition of forage herb species

    DEFF Research Database (Denmark)

    Warner, D.; Jensen, Søren Krogh; Cone, J.W.;

    2010-01-01

    The use of alternative forage species in grasslands for intensive livestock production is receiving renewed attention. Data on fatty acid composition of herbs are scarce, so four herbs (Plantago lanceolata, Achillea millefolium, Cichorium intybus, Pastinaca sativa) and one grass species (timothy...

  16. Wave overtopping resistance of grassed dike slopes in Vietnam

    NARCIS (Netherlands)

    Trung, L.H.; Van der Meer, J.W.; Luong, N.Q.; Verhagen, H.J.; Schiereck, G.J.

    2011-01-01

    The resistance of various grassed slopes against wave overtopping has been appraised by means of the Wave Overtopping Simulator in situ for a couple of years in Viet Nam. Destructive test results show that a dike slope covered with grass could suffer a certain overtopping discharge not smaller than

  17. Conceptual model for reinforced grass on inner dike slopes

    NARCIS (Netherlands)

    ComCoast

    2005-01-01

    A desk study has been carried out in order to develop a conceptual model for the erosion of inner dike slopes with reinforced grass cover. Based on the results the following can be concluded: The presence of a geosynthetic in a grass slope can be taken into account in the EPM method by increasing th

  18. Criteria of response of lawn grass to the environmental pollution

    OpenAIRE

    Y. V. Likholat

    2005-01-01

    Growth, physiological and biochemical criteria of reaction of the lawn grass on heavy metals influence are ascertained. Connection between levels of the heavy metals accumulation and changes of morphological parameters and activity of antioxidative protection enzymes of the plants is shown. Revealed specific features of lawn grasses stability to separate pollutants (heavy metals) action will be used for gardening industrial sites.

  19. MACRO NUTRIENTS UPTAKE OF FORAGE GRASSES AT DIFFERENT SALINITY STRESSES

    Directory of Open Access Journals (Sweden)

    F. Kusmiyati

    2014-10-01

    Full Text Available The high concentration of sodium chloride (NaCl in saline soils has negative effects on the growth ofmost plants. The experiment was designed to evaluate macro nutrient uptake (Nitrogen, Phosphorus andPotassium of forage grasses at different NaCl concentrations in growth media. The experiment wasconducted in a greenhouse at Forage Crops Laboratory of Animal Agriculture Faculty, Diponegoro University.Split plot design was used to arrange the experiment. The main plot was forage grasses (Elephant grass(Pennisetum purpureum and King grass (Pennisetum hybrida. The sub plot was NaCl concentrationin growth media (0, 150, and 300 mM. The nitrogen (N, phosphorus (P and potassium (K uptake in shootand root of plant were measured. The result indicated increasing NaCl concentration in growth mediasignificantly decreased the N, P and K uptake in root and shoot of the elephant grass and king grass. Thepercentage reduction percentage of N, P and K uptake at 150 mM and 300 mM were high in elephant grassand king grass. It can be concluded that based on nitrogen, phosphorus and potassium uptake, elephantgrass and king grass are not tolerant to strong and very strong saline soil.

  20. Genome Sequencing and Analysis of the Model Grass Brachypodium Distachyon.

    Science.gov (United States)

    Three subfamilies of grasses, the Ehrhartoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the compl...

  1. Native Grass Community Management Plan for the Oak Ridge Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Ryon, Michael G [ORNL; Parr, Patricia Dreyer [ORNL; Cohen, Kari [ORNL

    2007-06-01

    Land managers at the Department of Energy's Oak Ridge National Laboratory in East Tennessee are restoring native warm-season grasses and wildflowers to various sites across the Oak Ridge Reservation (ORR). Some of the numerous benefits to planting native grasses and forbs include improved habitat quality for wildlife, improved aesthetic values, lower long-term maintenance costs, and compliance with Executive Order 13112 (Clinton 1999). Challenges to restoring native plants on the ORR include the need to gain experience in establishing and maintaining these communities and the potentially greater up-front costs of getting native grasses established. The goals of the native grass program are generally outlined on a fiscal-year basis. An overview of some of the issues associated with the successful and cost-effective establishment and maintenance of native grass and wildflower stands on the ORR is presented in this report.

  2. A comparative view of the evolution of grasses under domestication.

    Science.gov (United States)

    Glémin, Sylvain; Bataillon, Thomas

    2009-01-01

    Crop grasses were among the first plants to be domesticated c. 12,000 yr ago, and they still represent the main staple crops for humans. During domestication, as did many other crops, grasses went through dramatic genetic and phenotypic changes. The recent massive increase in genomic data has provided new tools to investigate the genetic basis and consequences of domestication. Beyond the genetics of domestication, many aspects of grass biology, including their phylogeny and developmental biology, are also increasingly well studied, offering a unique opportunity to analyse the domestication process in a comparative way. Taking such a comparative point of view, we review the history of domesticated grasses and how domestication affected their phenotypic and genomic diversity. Considering recent theoretical developments and the accumulation of genetic data, we revisit more specifically the role of mating systems in the domestication process. We close by suggesting future directions for the study of domestication in grasses.

  3. Methane emission from tropical savanna Trachypogon sp. grasses

    Directory of Open Access Journals (Sweden)

    E. Sanhueza

    2006-01-01

    Full Text Available Methane flux measurements from the soil-grass system were made during the wet season in unperturbed plots and plots where standing dry and green Trachypogon sp. grasses were clipped to just above the soil surface. Results support the surprising discovery that vegetation emits methane. The results of this work allows to infer that the savanna dry/green mixture of grasses produce methane at a rate of ~10 ng m−2 s−1, which is in agreement with early published soil-grass system fluxes. An extrapolation of this flux to the global savanna produces an annual emission much lower than the CH4 production recently suggested in the literature. On the other hand, during the wet season savanna soil consume CH4 at a rate of ~4.7 ng m−2 s−1. Therefore, the tropical savanna soil-grass system would make a modest contribution to the global budget of methane.

  4. An optimized chloroplast DNA extraction protocol for grasses (Poaceae proves suitable for whole plastid genome sequencing and SNP detection.

    Directory of Open Access Journals (Sweden)

    Kerstin Diekmann

    Full Text Available BACKGROUND: Obtaining chloroplast genome sequences is important to increase the knowledge about the fundamental biology of plastids, to understand evolutionary and ecological processes in the evolution of plants, to develop biotechnological applications (e.g. plastid engineering and to improve the efficiency of breeding schemes. Extraction of pure chloroplast DNA is required for efficient sequencing of chloroplast genomes. Unfortunately, most protocols for extracting chloroplast DNA were developed for eudicots and do not produce sufficiently pure yields for a shotgun sequencing approach of whole plastid genomes from the monocot grasses. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a simple and inexpensive method to obtain chloroplast DNA from grass species by modifying and extending protocols optimized for the use in eudicots. Many protocols for extracting chloroplast DNA require an ultracentrifugation step to efficiently separate chloroplast DNA from nuclear DNA. The developed method uses two more centrifugation steps than previously reported protocols and does not require an ultracentrifuge. CONCLUSIONS/SIGNIFICANCE: The described method delivered chloroplast DNA of very high quality from two grass species belonging to highly different taxonomic subfamilies within the grass family (Lolium perenne, Pooideae; Miscanthus x giganteus, Panicoideae. The DNA from Lolium perenne was used for whole chloroplast genome sequencing and detection of SNPs. The sequence is publicly available on EMBL/GenBank.

  5. Tracking the evolution of a cold stress associated gene family in cold tolerant grasses

    Directory of Open Access Journals (Sweden)

    Asp Torben

    2008-09-01

    Full Text Available Abstract Background Grasses are adapted to a wide range of climatic conditions. Species of the subfamily Pooideae, which includes wheat, barley and important forage grasses, have evolved extreme frost tolerance. A class of ice binding proteins that inhibit ice re-crystallisation, specific to the Pooideae subfamily lineage, have been identified in perennial ryegrass and wheat, and these proteins are thought to have evolved from a leucine-rich repeat phytosulfokine receptor kinase (LRR-PSR-like ancestor gene. Even though the ice re-crystallisation inhibition function of these proteins has been studied extensively in vitro, little is known about the evolution of these genes on the molecular level. Results We identified 15 putative novel ice re-crystallisation inhibition (IRI-like protein coding genes in perennial ryegrass, barley, and wheat. Using synonymous divergence estimates we reconstructed the evolution of the IRI-like gene family. We also explored the hypothesis that the IRI-domain has evolved through repeated motif expansion and investigated the evolutionary relationship between a LRR-domain containing IRI coding gene in carrot and the Pooideae IRI-like genes. Our analysis showed that the main expansion of the IRI-gene family happened ~36 million years ago (Mya. In addition to IRI-like paralogs, wheat contained several sequences that likely were products of polyploidisation events (homoeologs. Through sequence analysis we identified two short motifs in the rice LRR-PSR gene highly similar to the repeat motifs of the IRI-domain in cold tolerant grasses. Finally we show that the LRR-domain of carrot and grass IRI proteins both share homology to an Arabidopsis thaliana LRR-trans membrane protein kinase (LRR-TPK. Conclusion The diverse IRI-like genes identified in this study tell a tale of a complex evolutionary history including birth of an ice binding domain, a burst of gene duplication events after cold tolerant grasses radiated from rice

  6. Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics

    Directory of Open Access Journals (Sweden)

    BETTY MAULIYA BUSTAM

    2010-01-01

    Full Text Available Bustam BM (2010 Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics. Biodiversitas 11: 9-14. This research is one of many studies on stipoid grasses organized by the International Stipeae Working Group (ISWG. This research tested the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996 and tested how informative the micro morphological characters used. Data were collected from herbarium specimens of 36 species (33 species of Austrostipa, two species of Hesperostipa and one species of Anemanthele at Royal Botanic Gardens, Sydney. Twenty eight micro morphological characters were used. The data were collected from both adaxial and abaxial surfaces of leaves, and from the lemma epidermis using a scanning electron microscope (SEM. ISWG provided the molecular data. Parsimony analysis and a distance method (Unweighteic Pair Group with Arithmatic Mean: UPGMA were used to analyze mico morphological and molecular data separately. Only UPGMA analysis was used to analyze the combined data. The results support the monophyly of Austrostipa. However, there is a little support for the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996, other than for the consistent recognition of Falcatae. The characters for comparisons between genera are too homoplasious at this level and do not contain enough information for analyses at subgeneric level, a problem apparently shared with the DNA sequences.

  7. Vegetative hyphal fusion and subsequent nuclear behavior in Epichloe grass endophytes.

    Directory of Open Access Journals (Sweden)

    Jun-Ya Shoji

    Full Text Available Epichloë species (including the former genus Neotyphodium are fungal symbionts of many agronomically important forage grasses, and provide their grass hosts with protection from a wide range of biotic and abiotic stresses. Epichloë species include many interspecific hybrids with allodiploid-like genomes, which may provide the potential for combined traits or recombination to generate new traits. Though circumstantial evidence suggests that such interspecific hybrids might have arisen from nuclear fusion events following vegetative hyphal fusion between different Epichloë strains, this hypothesis has not been addressed empirically. Here, we investigated vegetative hyphal fusion and subsequent nuclear behavior in Epichloë species. A majority of Epichloë strains, especially those having a sexual stage, underwent self vegetative hyphal fusion. Vegetative fusion also occurred between two hyphae from different Epichloë strains. Though Epichloë spp. are uninucleate fungi, hyphal fusion resulted in two nuclei stably sharing the same cytoplasm, which might ultimately lead to nuclear fusion. In addition, protoplast fusion experiments gave rise to uninucleate putative hybrids, which apparently had two markers, one from each parent within the same nucleus. These results are consistent with the notion that interspecific hybrids arise from vegetative hyphal fusion. However, we also discuss additional factors, such as post-hybridization selection, that may be important to explain the recognized prevalence of hybrids in Epichloë species.

  8. Sustainable bioethanol production combining biorefinery principles using combined raw materials from wheat undersown with clover-grass.

    Science.gov (United States)

    Thomsen, Mette Hedegaard; Hauggaard-Nielsen, Henrik; Haugaard-Nielsen, Henrik

    2008-05-01

    To obtain the best possible net energy balance of the bioethanol production the biomass raw materials used need to be produced with limited use of non-renewable fossil fuels. Intercropping strategies are known to maximize growth and productivity by including more than one species in the crop stand, very often with legumes as one of the components. In the present study clover-grass is undersown in a traditional wheat crop. Thereby, it is possible to increase input of symbiotic fixation of atmospheric nitrogen into the cropping systems and reduce the need for fertilizer applications. Furthermore, when using such wheat and clover-grass mixtures as raw material, addition of urea and other fermentation nutrients produced from fossil fuels can be reduced in the whole ethanol manufacturing chain. Using second generation ethanol technology mixtures of relative proportions of wheat straw and clover-grass (15:85, 50:50, and 85:15) were pretreated by wet oxidation. The results showed that supplementing wheat straw with clover-grass had a positive effect on the ethanol yield in simultaneous saccharification and fermentation experiments, and the effect was more pronounced in inhibitory substrates. The highest ethanol yield (80% of theoretical) was obtained in the experiment with high fraction (85%) of clover-grass. In order to improve the sugar recovery of clover-grass, it should be separated into a green juice (containing free sugars, fructan, amino acids, vitamins and soluble minerals) for direct fermentation and a fibre pulp for pretreatment together with wheat straw. Based on the obtained results a decentralized biorefinery concept for production of biofuel is suggested emphasizing sustainability, localness, and recycling principles. PMID:18338188

  9. Extreme genetic diversity in asexual grass thrips populations.

    Science.gov (United States)

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations. PMID:26864612

  10. Seed defensins of barnyard grass Echinochloa crusgalli (L.) Beauv.

    Science.gov (United States)

    Odintsova, Tatyana I; Rogozhin, Eugene A; Baranov, Yurij; Musolyamov, Alexander Kh; Yalpani, Nasser; Egorov, Tsezi A; Grishin, Eugene V

    2008-01-01

    From the annual weed barnyard grass Echinochloa crusgalli (L.) Beauv., two novel defensins Ec-AMP-D1 and Ec-AMP-D2 that differ by a single amino acid substitution were isolated by a combination of different chromatographic procedures. Both defensins were active against several phytopathogenic fungi and the oomycete Phytophthora infestans at micromolar concentrations. The Ec-AMP-D1 showed higher activity against the oomycete than Ec-AMP-D2. The comparison of the amino acid sequences of the antifungal E. crusgalli defensins with those of earlier characterized T. kiharae defensins [T.I. Odintsova, Ts.A. Egorov, A.Kh. Musolyamov, M.S. Odintsova, V.A. Pukhalsky, E.V. Grishin, Seed defensins from T. kiharae and related species: genome localization of defensin-encoding genes, Biochimie, 89 (2007) 605-612.] that were devoid of substantial antifungal activity point to the C-terminal region of the molecule as the main determinant of the antifungal activity of E. crusgalli defensins.

  11. Potential Effects of the Loss of Native Grasses on Grassland Invertebrate Diversity in Southeastern Australia

    Directory of Open Access Journals (Sweden)

    Roger Edgcumbe Clay

    2014-01-01

    Full Text Available Reduction in area of the southeastern temperate grasslands of Australia since European settlement has been accompanied by degradation of remaining remnants by various factors, including the replacement of native plant species by introduced ones. There are suggestions that these replacements have had deleterious effects on the invertebrate grassland community, but there is little evidence to support these suggestions. In the eastern Adelaide Hills of South Australia, four grassland invertebrate sampling areas, in close proximity, were chosen to be as similar as possible except for the visible amount of native grass they contained. Sample areas were surveyed in four periods (summer, winter, spring, and a repeat summer using pitfall traps and sweep-netting. A vegetation cover survey was conducted in spring. Morphospecies richness and Fisher’s alpha were compared and showed significant differences between sample areas, mainly in the summer periods. Regression analyses between morphospecies richness and various features of the groundcover/surface showed a strong positive and logical association between native grass cover and morphospecies richness. Two other associations with richness were less strong and lacked a logical explanation. If the suggested direct effect of native grass cover on invertebrate diversity is true, it has serious implications for the conservation of invertebrate biodiversity.

  12. Plant growth and soil microbial community structure of legumes and grasses grown in monoculture or mixture

    Institute of Scientific and Technical Information of China (English)

    CHEN Meimei; CHEN Baodong; MARSCHNER Petra

    2008-01-01

    A greenhouse pot experiment was conducted to investigate the influence of soil moisture eontent on plant growth and the rhizospheremicrobial community structure of four plant species (white clover, alfalfa, sudan grass, tall fescue), grown individually or in a mixture.The soil moisture content was adjusted to 55% or 80% water holding capacity (WHC). The results indicated that the total plant biomassof one pot was lower at 55% WHC. At a given soil moisture, the total plant biomass of white clover and tall fescue in the mixture waslower than that in a monoculture, indicating their poor competitiveness. For leguminous plants, the decrease in soil moisture reducedthe total microbial biomass, bacterial biomass, fungal biomass, and fungal/baeterial ratio in soil as assessed by the phospholipid fattyacid analysis, whereas, lower soil moisture increased those parameters in the tall fescue. The microbial biomass in the soil with legumeswas higher than that in the soil with grasses and the two plant groups differed in soil microbial community composition. At high soilmoisture content, microbial communities of the plant mixture were similar to those of the legume monoculture, and the existenceof legumes in the mixture enhanced the bacterial and fungal biomass in the soil compared to the grasses grown in the monoculture,indicating that legumes played a dominant role in the soil microbial community changes in the plant mixture.

  13. An integrated physical, genetic and cytogenetic map of Brachypodium distachyon, a model system for grass research.

    Directory of Open Access Journals (Sweden)

    Melanie Febrer

    Full Text Available The pooid subfamily of grasses includes some of the most important crop, forage and turf species, such as wheat, barley and Lolium. Developing genomic resources, such as whole-genome physical maps, for analysing the large and complex genomes of these crops and for facilitating biological research in grasses is an important goal in plant biology. We describe a bacterial artificial chromosome (BAC-based physical map of the wild pooid grass Brachypodium distachyon and integrate this with whole genome shotgun sequence (WGS assemblies using BAC end sequences (BES. The resulting physical map contains 26 contigs spanning the 272 Mb genome. BES from the physical map were also used to integrate a genetic map. This provides an independent validation and confirmation of the published WGS assembly. Mapped BACs were used in Fluorescence In Situ Hybridisation (FISH experiments to align the integrated physical map and sequence assemblies to chromosomes with high resolution. The physical, genetic and cytogenetic maps, integrated with whole genome shotgun sequence assemblies, enhance the accuracy and durability of this important genome sequence and will directly facilitate gene isolation.

  14. The effect of timing of growing season drought on flowering of a dominant C4 grass.

    Science.gov (United States)

    Dietrich, John D; Smith, Melinda D

    2016-06-01

    Timing of precipitation is equally important as amount for determining ecosystem function, especially aboveground net primary productivity (ANPP), in a number of ecosystems. In tallgrass prairie of the Central Plains of North America, grass flowering stalks of dominant C4 grasses, such as Andropogon gerardii, can account for more than 70 % of ANPP, or almost none of it, as the number of flowering stalks produced is highly variable. Although growing season precipitation amount is important for driving variation in flowering stalk production, it remains unknown whether there are critical periods within the growing season in which sufficient rainfall must occur to allow for flowering. The effect of timing of rainfall deficit (drought) on flowering of A. gerardii, was tested by excluding rainfall during three periods within the growing season (starting in mid-April, mid-May and mid-June). Mid-summer drought (starting in mid-June) strongly reduced the flowering rate (e.g., density and biomass) of A. gerardii (e.g., as high as 94 % compared to the control), suggesting flowering is highly sensitive to precipitation at this time. This effect appeared to be related to plant water status at the time of flowering stalk initiation, rather than an indirect consequence of reduced C assimilation. Our results suggest that increased frequency of growing season drought forecast with climate change could reduce sexual reproduction in this dominant grass species, particularly if it coincides with timing of flowering stalk initiation, with important implications for ecosystem functioning. PMID:26886131

  15. Performances of legume-grass mixtures under different cutting managements in mediterranean environments

    Directory of Open Access Journals (Sweden)

    Pasquale Martiniello

    2011-02-01

    Full Text Available Annual forage crops have great importance for sustaining animal production in southern Italy. Knowledge of the performance of legume-grass associations under management similar to systems encountered in farm practice is essential for their effective exploitation of the available environmental resources. The purpose of this investigation was to estimate the effects of five cutting managements on the productivity and botanical composition of ten annual fodder crop mixtures in two Mediterranean environments. Ten ternary combinations of one grass (Avena sativa L., oat and Lolium multiflorum Lam., Italian ryegrass, one clover (Trifolium alexandrinum L., berseem; Trifolium incarnatum L., crimson and Trifolium squarrosum L., squarrosum or burr medic (Medicago polymorpha L. and common vetch (Vicia sativa L. were compared in a field trial (split-plot design, 3 replicates in two locations (Cagliari and Foggia, Italy during the 2000-2001 growing season. The cutting treatments included a winter grazing simulation (G, a cutting only regime at early (EF or late flowering (F of legumes and a combination of treatments (GEF and GF. Plant density (no. m-2 prior to cutting, dry matter yield (g m-2 and botanical composition (% were evaluated. Considerable differences were observed in the harvestable dry matter yields of mixtures among cutting treatments in both localities, with treatment F showing the higher values (787.1 and 415.7 g m-2 for Cagliari and Foggia, respectively. The forage species were able to compete and establish good growth during their initial phase in both localities. However, the botanical composition between the two sites differed considerably after the winter period. Particularly, at Foggia, grass dominance was a permanent feature of all treatments, and all the mixtures contained about 84% of grass. Italian ryegrass was the most representative species under all treatments in both sites. Mixtures with Italian ryegrass, crimson or berseem

  16. Grass carp in the Great Lakes region: establishment potential, expert perceptions, and re-evaluation of experimental evidence of ecological impact

    Science.gov (United States)

    Wittmann, Marion E.; Jerde, Christopher L.; Howeth, Jennifer G.; Maher, Sean P.; Deines, Andrew M.; Jenkins, Jill A.; Whitledge, Gregory W.; Burbank, Sarah B.; Chadderton, William L.; Mahon, Andrew R.; Tyson, Jeffrey T.; Gantz, Crysta A.; Keller, Reuben P.; Drake, John M.; Lodge, David M.

    2014-01-01

    Intentional introductions of nonindigenous fishes are increasing globally. While benefits of these introductions are easily quantified, assessments to understand the negative impacts to ecosystems are often difficult, incomplete, or absent. Grass carp (Ctenopharyngodon idella) was originally introduced to the United States as a biocontrol agent, and recent observations of wild, diploid individuals in the Great Lakes basin have spurred interest in re-evaluating its ecological risk. Here, we evaluate the ecological impact of grass carp using expert opinion and a suite of the most up-to-date analytical tools and data (ploidy assessment, eDNA surveillance, species distribution models (SDMs), and meta-analysis). The perceived ecological impact of grass carp by fisheries experts was variable, ranging from unknown to very high. Wild-caught triploid and diploid individuals occurred in multiple Great Lakes waterways, and eDNA surveillance suggests that grass carp are abundant in a major tributary of Lake Michigan. SDMs predicted suitable grass carp climate occurs in all Great Lakes. Meta-analysis showed that grass carp introductions impact both water quality and biota. Novel findings based on updated ecological impact assessment tools indicate that iterative risk assessment of introduced fishes may be warranted.

  17. Dormancy and germination of Johnson grass seed (Sorghum halepense (L. Pers.

    Directory of Open Access Journals (Sweden)

    Renata BALIČEVIĆ

    2016-09-01

    Full Text Available The aim of the research was to determine the effectiveness of various methods for breaking seed dormancy of weed species Johnson grass (Sorghum halepense (L. Pers. and their influence on germination and seedlings growth. Beside control treatment, eight treatments for breaking dormancy of seeds were applied: seed immersion in distilled water for 24 hours; seed immersion in water at 60 °C for 1 hour; immersion in a 0.2% solution of potassium nitrate for 24 hours; immersion in 2% solution of sodium hypochlorite for 8 hours; treatments with concentrated sulphuric acid for 5 and 10 minutes; treatment with concentrated sulphuric acid for 5 minutes and germination in darkness; and combined treatment of sulphuric acid (5 minutes and 1.5% potassium nitrate solution (2 hours. Average germination of Johnson grass seeds in control treatment was very low, only 2.8%. All dormancy breaking treatments increased seed germination and the highest germination was observed in treatment with combination of sulphuric acid and potassium nitrate (35.0% and treatment with 2% sodium hypochlorite (30.6%. However, sodium hypochlorite reduced root length of seedlings for 40.9% compared to control, while all treatments had a positive effect on Johnson grass shoot length. Total seedlings length was the highest when seeds were treated for 5 minutes with sulphuric acid. None of the treatments showed significant effect on Johnson grass seedlings fresh weight. Seed germinated fastest in treatment with a combination of sulphuric acid and potassium nitrate (4.58 days, and slowest when seeds were immersed in water (8.16 days and in the 2% solution of sodium hypochlorite (8.92 days.

  18. Field-Scale Partitioning of Ecosystem Respiration Components Suggests Carbon Stabilization in a Bioenergy Grass Ecosystem

    Science.gov (United States)

    Black, C. K.; Miller, J. N.; Masters, M. D.; Bernacchi, C.; DeLucia, E. H.

    2014-12-01

    Annually-harvested agroecosystems have the potential to be net carbon sinks only if their root systems allocate sufficient carbon belowground and if this carbon is then retained as stable soil organic matter. Soil respiration measurements are the most common approach to evaluate the stability of soil carbon at experimental time scales, but valid inferences require the partitioning of soil respiration into root-derived (current-year C) and heterotrophic (older C) components. This partitioning is challenging at the field scale because roots and soil are intricately mixed and physical separation in impossible without disturbing the fluxes to be measured. To partition soil flux and estimate the C sink potential of bioenergy crops, we used the carbon isotope difference between C3 and C4 plant species to quantify respiration from roots of three C4 grasses (maize, Miscanthus, and switchgrass) grown in a site with a mixed cropping history where respiration from the breakdown of old soil carbon has a mixed C3-C4 signature. We used a Keeling plot approach to partition fluxes both at the soil surface using soil chambers and from the whole field using continuous flow sampling of air within and above the canopy. Although soil respiration rates from perennial grasses were higher than those from maize, the isotopic signature of respired carbon indicated that the fraction of soil CO2 flux attributable to current-year vegetation was 1.5 (switchgrass) to 2 (Miscanthus) times greater in perennials than that from maize, indicating that soil CO2 flux came mostly from roots and turnover of soil organic matter was reduced in the perennial crops. This reduction in soil heterotrophic respiration, combined with the much greater quantities of C allocated belowground by perennial grasses compared to maize, suggests that perennial grasses grown as bioenergy crops may be able to provide an additional climate benefit by acting as carbon sinks in addition to reducing fossil fuel consumption.

  19. Endophyte isolate and host grass effects on Chaetocnema pulicaria (Coleoptera: Chrysomelidae) feeding.

    Science.gov (United States)

    Ball, Olivier J P; Gwinn, Kimberly D; Pless, Charles D; Popay, Alison J

    2011-04-01

    Endophytic fungi belonging to the genus Neotyphodium, confer resistance to infected host grasses against insect pests. The effect of host species, and endophtye species and strain, on feeding and survival of the corn flea beetle, Chaetocnema pulicaria Melsheimer (Coleoptera: Chrysomelidae) was investigated. The grass-endophyte associations included natural and artificially derived associations producing varying arrays of common endophyte-related alkaloids or alkaloid groups, peramine, lolitrem B, ergovaline, and the lolines. Preference and nonpreference tests showed that C. pulicaria feeding and survival were reduced by infection of tall fescue with the wild-type strain of N. coenophialum, the likely mechanism being antixenosis rather than antibiosis. In the preference tests, endophyte and host species effects were observed. Of the 10 different Neotyphodium strains tested in artificially derived tall fescue associations, eight strongly deterred feeding by C. pulicaria, whereas the remaining two strains had little or no effect on feeding. Infection of tall fescue with another fungal symbiont, p-endophyte, had no effect. Perennial ryegrass, Lolium perenne L., infected with six strains of endophyte, was moderately resistant to C. pulicaria compared with endophyte-free grass, but four additional strains were relatively inactive. Six Neotyphodium-meadow fescue, Festuca pratensis Huds., associations, including the wild-type N. uncinatum-meadow fescue combination, were resistant, whereas three associations were not effective. Loline alkaloids seemed to play a role in antixenosis to C. pulicaria. Effects not attributable to the lolines or any other of the alkaloids examined also were observed. This phenomenon also has been reported in tests with other insects, and indicates the presence of additional insect-active factors.

  20. Distinct physiological responses underlie defoliation tolerance in African lawn and bunch grasses

    NARCIS (Netherlands)

    Anderson, T.M.; Kumordzi, B.B.; Fokkema, W.; Valls Fox, H.; Olff, H.

    2013-01-01

    Premise of research. African grass communities are dominated by two distinct functional types: tall, caespitose bunch grasses and short, spreading lawn grasses. Functional type coexistence has been explained by differences in defoliation tolerance, because lawn grasses occur in intensively grazed ar

  1. Grass-Shrub Associations over a Precipitation Gradient and Their Implications for Restoration in the Great Basin, USA.

    Directory of Open Access Journals (Sweden)

    Maike F Holthuijzen

    Full Text Available As environmental stress increases positive (facilitative plant interactions often predominate. Plant-plant associations (or lack thereof can indicate whether certain plant species favor particular types of microsites (e.g., shrub canopies or plant-free interspaces and can provide valuable insights into whether "nurse plants" will contribute to seeding or planting success during ecological restoration. It can be difficult, however, to anticipate how relationships between nurse plants and plants used for restoration may change over large-ranging, regional stress gradients. We investigated associations between the shrub, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis, and three common native grasses (Poa secunda, Elymus elymoides, and Pseudoroegneria spicata, representing short-, medium-, and deep-rooted growth forms, respectively, across an annual rainfall gradient (220-350 mm in the Great Basin, USA. We hypothesized that positive shrub-grass relationships would become more frequent at lower rainfall levels, as indicated by greater cover of grasses in shrub canopies than vegetation-free interspaces. We sampled aerial cover, density, height, basal width, grazing status, and reproductive status of perennial grasses in canopies and interspaces of 25-33 sagebrush individuals at 32 sites along a rainfall gradient. We found that aerial cover of the shallow rooted grass, P. secunda, was higher in sagebrush canopy than interspace microsites at lower levels of rainfall. Cover and density of the medium-rooted grass, E. elymoides were higher in sagebrush canopies than interspaces at all but the highest rainfall levels. Neither annual rainfall nor sagebrush canopy microsite significantly affected P. spicata cover. E. elymoides and P. spicata plants were taller, narrower, and less likely to be grazed in shrub canopy microsites than interspaces. Our results suggest that exploring sagebrush canopy microsites for restoration of native perennial

  2. Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

    DEFF Research Database (Denmark)

    Pirhofer-Walzl, Karin; Høgh Jensen, Henning; Eriksen, Jørgen;

    2012-01-01

    Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red ...

  3. An Ecofeminist Approach to The Grass Is Singing

    Institute of Scientific and Technical Information of China (English)

    张娜

    2014-01-01

    The article intends to interpret The Grass Is Singing from the perspective of ecofeminism and analyze the unequal rela-tionships between man and nature, man and woman, the white race and the black race.

  4. Growing grass for a green biorefinery - an option for Ireland?

    NARCIS (Netherlands)

    O'Keeffe, S.; Schulte, R.P.O.; O'Kiely, P.; O'Donoghue, C.; Lalor, S.T.J.; Struik, P.C.

    2010-01-01

    Growing grass for a green biorefinery – an option for Ireland? Mind the gap: deciphering the gap between good intentions and healthy eating behaviour Halting biodiversity loss by 2020 – implications for agriculture A milk processing sector model for Ireland

  5. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Science.gov (United States)

    2010-01-01

    ... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat, wheat... family, Poaceae (Gramineae). Kinds of seed: Bentgrasses, bluegrasses, bluestems, bromes, cereals,...

  6. INFECTIVITY OF METARHIZIUM ANISOPLIAE IN GRASS SHRIMP EMBRYOS

    Science.gov (United States)

    Developing embryos of the estuarine grass shrimp, Palaemonetes pugio, were exposed to Metarhizium anisopliae conidiospores. Attachment of conidiospores was often followed by germination and outgrowth on embryo surface. Penetration of the embryonic envelopes by M. anisopliae allow...

  7. Photoinhibition of germination in grass seed--implications for prairie revegetation.

    Science.gov (United States)

    Mollard, Federico P O; Naeth, M Anne

    2014-09-01

    Germination photoinhibition is not a recognized cause of revegetation failure; yet prolonged sunlight exposure can inhibit germination of several grass species. This research addressed susceptibility to photoinhibition of selected native grass species used to restore Canadian prairies, and reclamation treatments to alter environmental conditions in order to release seeds from photoinhibition. Under laboratory conditions effects of photoinhibition were tested on the ability of seeds to germinate at low water potential and effects of daily alternating temperatures and nitrates to break photoinhibition. Whether surficial mulch can release seeds from photoinhibition was assessed in a field experiment. Germination photoinhibition was evident in Festuca hallii and Koeleria macrantha seeds even under very low irradiances. The prolonged exposure to light decreased germination rates and ability of seeds to germinate at low water potentials. Daily fluctuating temperatures released a fraction of Bromus carinatus and Elymus trachycaulus seeds from photoinhibition yet did not improve F. hallii or K. macrantha germinability. Nitrates failed to break seed photoinhibition in all species tested. In the field experiment, mulched F. hallii seeds (covered with an erosion control blanket) showed a tenfold increase in germination percentages relative to seeds exposed to direct sunlight, indicating the facilitative effects of mulching on attenuation of the light environment. We conclude that germination photoinhibition as a cause of emergence failures in land reclamation where seed is broadcast or shallow seeded should be recognized and germination photoinhibition included in the decision making process to select revegetation seeding techniques.

  8. Preference for different inorganic nitrogen forms among plant functional types and species of the Patagonian steppe.

    Science.gov (United States)

    Gherardi, Laureano A; Sala, Osvaldo E; Yahdjian, Laura

    2013-11-01

    We have explored species-specific preferences for nitrate (NO3(-)) and ammonium (NH4(+)) as an alternative niche separation in ecosystems where nitrogen (N) is present mostly in inorganic forms. The Patagonian steppe is dominated by shrubs and grasses. Shrubs absorb water and nutrients from deep soil layers, which are poor in N, while grasses have the opposite pattern, absorbing most of their water and nutrients from the upper layers of the soil. We hypothesized that the preferences of shrub and grass for inorganic N forms are different and that the rate of potential N uptake is greater in shrubs than in grasses. To test this hypothesis, we grew individuals of six dominant species in solutions of different NH4(+):NO3(-) concentration ratios. Nitrate uptake was found to be higher in shrubs, while ammonium uptake was similar between plant functional types. The NH4(+):NO3(-) uptake ratio was significantly lower for shrubs than grasses. Shrubs, which under field conditions have deeper rooting systems than grasses, showed a higher N absorption capacity than grasses and a preference for the more mobile N form, nitrate. Grasses, which had lower N uptake rates than shrubs, preferred ammonium over nitrate. These complementary patterns between grasses and shrubs suggest a more thorough exploitation of resources by diverse ecosystems than those dominated by just one functional type. The loss of one plant functional group or a significant change in its abundance would therefore represent a reduction in resource use efficiency and ecosystem functioning. PMID:23812108

  9. Investigation of the Interactions Among Grass, Chlorophenols and Microbes

    OpenAIRE

    Crane, Cynthia Elizabeth

    1999-01-01

    Studies were conducted to explore the interactions among rye grass, chlorophenols and microorganisms. The objectives were to examine some of the processes by which plants affect the fate of subsurface organic contaminants. The research was divided into three studies: interactions between live grasses and 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP); physico-chemical interactions between the three chlorophenols and root tissue; and effect of root exudate...

  10. Grass buffers for playas in agricultural landscapes: An annotated bibliography

    Science.gov (United States)

    Melcher, Cynthia P.; Skagen, Susan K.

    2005-01-01

    This bibliography and associated literature synthesis (Melcher and Skagen, 2005) was developed for the Playa Lakes Joint Venture (PLJV). The PLJV sought compilation and annotation of the literature on grass buffers for protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants. In addition, PLJV sought information regarding the extent to which buffers may attenuate the precipitation runoff needed to fill playas, and avian use of buffers. We emphasize grass buffers, but we also provide information on other buffer types.

  11. Biomethane production from grass silage: laboratory assessment to maximise yields

    OpenAIRE

    Wall, David M.

    2015-01-01

    On-farm biogas production is typically associated with forage maize as the biomass source. Digesters are designed and operated with the focus of optimising the conditions for this feedstock. Thus, such systems may not be ideally suited to the digestion of grass. Ireland has ca. 3.85 million ha of grassland. Annual excess grass, surplus to livestock requirements, could potentially fuel an anaerobic digestion industry. Biomethane associated with biomass from 1.1 % of grassland in Ireland, could...

  12. Signal Grass (Brachiaria decumbens) Toxicity in Grazing Ruminants

    OpenAIRE

    Susan G. Low

    2015-01-01

    Signal grass (Brachiaria decumbens) is a highly productive tropical grass that is widespread through South America, Australia, Indonesia, Vanuatu and Malaysia due to its adaptation to a wide range of soil types and environments. Animal production from these B. decumbens pastures is highly variable due to sporadic outbreaks of photosensitisation associated with low growth rates of young animals, anorexia and wasting. The identification of B. decumbens toxicity through clinical signs may gross...

  13. Morphophysiological characterization of giant missionary grass accessions

    Directory of Open Access Journals (Sweden)

    Cristiano Reschke Lajús

    2011-11-01

    Full Text Available In this study, the phenotypic diversity of five accessions of giant missionary grass (Axonopus jesuiticus × A. scoparius was evaluated by using morphophysiological traits. Accessions V 14337, V 14403, V 14404, V 14405 and V 14406 are hybrids derived from spontaneous crossing that occurred in Vale do Itajaí, Santa Catarina, Brazil. Plants were cultivated in greenhouse and evaluated at 60, 90, 120, 150, 180, 210 and 240 days of growth. Variation was observed for dry matter production, phenology and morphological traits, showing the possibility of selection. Flowering started at 210 days of growth and only in accessions V 14337 and V 14404. The Mahalanobis distance among accessions ranged from 35.64 (V 14403 and V 14405 to 183.38 (V 14337 and V 14405, and three groups were formed, based on 17 vegetative morphophysiological traits evaluated in plants with 180 days of growth: G1 (V 14403, V 14405, G2 (V 14406 and G3 (V 14337, V 14404. Group I presented the greatest dry matter production of stolon and aboveground, which were the traits with the largest relative contribution to genetic divergence, 38.67% and 38.31%, respectively. Accessions V 14403 and V 14405 are the most promising for agronomic evaluations that address their records as forage cultivars.

  14. Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses

    OpenAIRE

    Cardoso, Juan Andrés; Pineda, Marcela; Jiménez, Juan de la Cruz; Vergara, Manuel Fernando; Rao, Idupulapati M.

    2015-01-01

    Drought severely limits forage productivity of C4 grasses across the tropics. The avoidance of water deficit by increasing the capacity for water uptake or by controlling water loss are common responses in forage C4 grasses. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C4 grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to overcome wat...

  15. Differential expression of two C-type lectins in grass carp Ctenopharyngodon idella and their response to grass carp reovirus.

    Science.gov (United States)

    Ju, C S; He, L B; Pei, Y Y; Jiang, Y; Huang, R; Li, Y M; Liao, L J; Jang, S H; Wang, Y P

    2016-02-01

    The cDNAs of two C-type lectins in grass carp Ctenopharyngodon idella, galactose-binding lectin (galbl) and mannose-binding lectin (mbl), were cloned and analysed in this study. Both of them exhibited the highest expression level in liver, whereas their expression pattern differed in early phase of embryonic development. Following exposure to grass carp reovirus (GCRV), the mRNA expression level of galbl and mbl was significantly up-regulated in liver and intestine. PMID:26643267

  16. Plant-soil feedbacks promote negative frequency dependence in the coexistence of two aridland grasses.

    Science.gov (United States)

    Chung, Y Anny; Rudgers, Jennifer A

    2016-07-27

    Understanding the mechanisms of species coexistence is key to predicting patterns of species diversity. Historically, the ecological paradigm has been that species coexist by partitioning resources: as a species increases in abundance, self-limitation kicks in, because species-specific resources decline. However, determining coexistence mechanisms has been a particular puzzle for sedentary organisms with high overlap in their resource requirements, such as plants. Recent evidence suggests that plant-associated microbes could generate the stabilizing self-limitation (negative frequency dependence) that is required for species coexistence. Here, we test the key assumption that plant-microbe feedbacks cause such self-limitation. We used competition experiments and modelling to evaluate how two common groups of soil microbes (rhizospheric microbes and biological soil crusts) influenced the self-limitation of two competing desert grass species. Negative feedbacks between the dominant plant competitor and its rhizospheric microbes magnified self-limitation, whereas beneficial interactions between both plant species and biological soil crusts partly counteracted this stabilizing effect. Plant-microbe interactions have received relatively little attention as drivers of vegetation dynamics in dry land ecosystems. Our results suggest that microbial mechanisms can contribute to patterns of plant coexistence in arid grasslands. PMID:27466448

  17. The impact of drought stress on the yields and food value of selected forage grasses

    Directory of Open Access Journals (Sweden)

    Mariola Staniak

    2016-06-01

    Full Text Available The aim of the study was to compare yields and nutritional value of selected species and cultivars of forage grasses under the optimal moisture conditions and long-term drought stress. The regenerative capacity of plants after dehydration was also assessed. The pot experiment was conducted in years 2009–2010 in IUNG-PIB’s greenhouse in Puławy, Poland. Nine cultivars of four species: Dactylis glomerata (‘Amera’, ‘Minora’, Festuca pratensis (‘Skra’, ‘Fantazja’, Festulolium braunii (‘Felopa’, ‘Agula’, ‘Sulino’, and Lolium multiflorum (‘Gisel’, ‘Lotos’ were investigated in well-watered conditions (70% field water capacity – FWC and under a long-term drought stress (40% FWC. The study showed that stress caused by soil moisture deficiency significantly reduced yields of D. glomerata, F. pratensis, F. braunii, and L. multiflorum. The total yield of dry matter under stress conditions was about 31% lower, compared to the performance achieved on the optimally moisturized treatment. The smallest reduction in dry matter yield under the conditions of water deficit was recorded for D. glomerata, which makes it the most resistant to stress, followed by F. pratensis. The resistance of F. braunii and L. multiflorum to stress was similar and significantly lower. There was a various response of different grasses to the water stress. On the basis of the value of the DSI (drought susceptibility index, the tested cultivars were ranked depending on the sensitivity to drought, starting with the most resistant cultivar: ‘Minora’, ‘Skra’, ‘Fantazja’, ‘Amera’, ‘Sulino’, ‘Agula’, ‘Gisel’, ‘Lotos’, and ‘Felopa’. The digestibility of dry matter and nutrient value of the grasses depended on both the level of soil moisture and grass species. Under the water stress, the digestibility and protein value increased compared to the control objects. Lolium multiflorum and F. braunii had the best

  18. Vertical structure and diurnal variability of ammonia exchange potential within an intensively managed grass canopy

    Science.gov (United States)

    Herrmann, B.; Mattsson, M.; Jones, S. K.; Cellier, P.; Milford, C.; Sutton, M. A.; Schjoerring, J. K.; Neftel, A.

    2009-01-01

    Stomatal ammonia compensation points (χs) of grass species on a mixed fertilized grassland were determined by measurements of apoplastic [NH4+] and [H>+] in the field. Calculated χs values were compared with in-canopy atmospheric NH3 concentration (χa) measurements. Leaf apoplastic [NH4+] increased by a factor of two from the lowest level in the canopy to the top level. Bulk leaf [NH4+] and especially [NO3-] slightly increased at the bottom of the canopy and these concentrations were very high in senescent plant litter. Calculated χs values were below atmospheric χs at all canopy levels measured, indicating that the grassland was characterized by NH3 deposition before cutting. This was confirmed by the χa profile, showing the lowest χa close to the ground (15 cm above soil surface) and an increase in χa with canopy height. Neither χs nor χa could be measured close to the soil surface, however, the [NH4+] in the litter material indicated a high potential for NH3 emission. A diurnal course in apoplastic [NH4+] was seen in the regrowing grass growing after cutting, with highest concentration around noon. Both apoplastic and tissue [NH4+] increased in young grass compared to tall grass. Following cutting, in-canopy gradients of atmospheric χa showed NH3 emission but since calculated χs values of the cut grass were still lower than atmospheric NH3 concentrations, the emissions could not entirely be explained by stomatal NH3 loss. High tissue [NH4+] in the senescent plant material indicated that this fraction constituted an NH3 source. After fertilization, [NH4+] increased both in apoplast and leaf tissue with the most pronounced increase in the former compared to the latter. The diurnal pattern in apoplastic [NH4+] was even more pronounced after fertilization and calculated χs values were generally higher, but remained below atmospheric [NH3].

  19. Detection and characterization of fungal infections of Ammophila arenaria (marram grass) roots by denaturing gradient gel electrophoresis of specifically amplified 18S rDNA

    NARCIS (Netherlands)

    Kowalchuk, G.A.; Gerards, S.; Woldendorp, J.W.

    1997-01-01

    Marram grass (Ammophila arenaria L.), a sand stabilizing plant species in coastal dune areas, is affected by a specific pathosystem thought to include both plant-pathogenic fungi and nematodes, To study the fungal component of this pathosystem, we developed a method for the cultivation-independent d

  20. Physiological and Morphological Effects of High Water Tables on Early Growth of Giant Reed (Arundo donax), Elephant Grass (Pennisetum purpureum), Energycane and Sugarcane (Saccharum spp.)

    Science.gov (United States)

    Increasing demand for renewable energy sources has led to interest in high-biomass crops. Species that have been proposed as well-suited for biofuel production in the Everglades Agricultural Area (EAA) of Florida include Giant Reed (Arundo donax), Elephant Grass (Pennisetum purpureum), Energycane (S...

  1. Description of Pratylenchus dunensis sp. n. (Nematoda: Pratylenchidae), a root-lesion nematode associated with the dune grass Ammophila arenaria (L.) Link

    NARCIS (Netherlands)

    Peña, de la E.; Moens, M.; Aelst, van A.C.; Karssen, G.

    2006-01-01

    A root-lesion nematode, Pratylenchus dunensis sp. n., is described and illustrated from Ammophila arenaria (L.) Link, a grass occurring abundantly in coastal dunes of Atlantic Europe. The new species is characterised by medium sized (454-579 ¿ m) slender, vermiform, females and males having two lip

  2. The effect of reciprocal treatments with ozone and ultraviolet-B radiations on photosynthesis and growth of perennial grass Elymus athericus

    NARCIS (Netherlands)

    Staaij, van de J.W.M.; Tonneijck, A.E.G.; Rozema, J.

    1997-01-01

    The impact on plant growth of the simultaneously changing factors of the global climate, rising tropospheric O3 concentrations and increasing UV-B radiation fluxes, has been tested in a combined glasshouse and growth chamber experiment. The saltmarsh grass species Elymus athericus was sequentially f

  3. Upgraded fuel from reed canary grass

    Energy Technology Data Exchange (ETDEWEB)

    Heiskanen, V.P.

    1995-12-31

    The feasibility of RCG for commercial utilization depends primarily on its applicability for pulp production and its use in energy production will be based on the residue that will be available after extracting the pulp fraction of the RCG. Roughly 20 ..30% of the material will be available for energy production purposes. However, the percentage may be higher/lower depending on the quality standards of the pulp fiber material. The harvesting period has a significant effect on the fuel characteristics of RCG. For instance the contents of N, S, Cl, K are clearly lower if the RCG is harvested in the spring (delayed) instead of summer/autumn. These elements affect significantly overall emission formation and ash behaviour and its melting temperature. The combustion related research in this project has been focused on the spring-harvested RCG. The project aims to evaluate the feasibility of delayed harvested RCG for energy production. In order to reach this goal, the following combustion methods will be tested and studied: combustion of pelletized RCG; gasification; combustion of pulverized RCG. In addition, pelletizing, reactivity and NO conversion of pulverized RCG will be studied. The research described here is a part of `Reed Canary Grass` project (in AIR programme). The contractors of the project are Swedish University of Agricultural Sciences (coordinator), United Milling Systems from Denmark, Jaakko Poeyry Oy and VTT Energy. In addition, there are partners from several countries participating in the project. The project has been divided in five tasks, VTT Energy being responsible for combustion related task `Upgraded fuel` that includes the research topics discussed in this paper

  4. CONTROL OF GULLY EROSION USING STIFF GRASSES

    Institute of Scientific and Technical Information of China (English)

    F. D. SHIELDS, Jr.; S. M. DABNEY; E. J. LANGENDOEN; D. M. TEMPLE

    2005-01-01

    Concentrated flow can cause gully formation on sloping lands and in riparian zones. Current practice for riparian gully erosion control involves blocking the gully with a structure comprised of an earthen embankment and a metal or plastic pipe. Measures involving native vegetation would be more attractive for habitat recovery and economic reasons. To test the hypothesis that switchgrass (Panicum virgatum L.) hedges planted at 0.5-m vertical intervals within a gully would control erosion,a series of hedges was established in four concentrated flow channels. Two of the channels were previously eroded trapezoidal channels cut into compacted fill in an outdoor laboratory. The other two channels were natural gullies located at the edge of floodplain fields adjacent to an incised stream.While vegetation was dormant, artificial runoff events were created in the two laboratory gullies and one of the natural gullies using synthetic trapezoidal-shaped hydrographs with peak discharge rates of approximately 0.03, 0.07, and 0.16 m3/s. During these tests flow depth, velocity, turbidity, and soil pore water pressures were monitored. The fourth gully was subjected to a series of natural runoff events over a five-month period with peaks up to 0.09 m3/s. Flow depths in all tests were generally < 0.3 m, and flow velocities varied spatially and exceeded 2.0 m/s at the steepest points of the gullies.Erosion rates were negligible for controlled flow experiments, but natural flows in the fourth gully resulted in 1 m of thalweg degradation, destroying the central portions of the grass hedges, most likely due to the highly erodible nature of the soils at this site. Geotechnical modeling of soil steps reinforced with switchgrass roots showed factors of safety > 1 for step heights < 0.5 m, but instability was indicated for step heights > 1 m, consistent with the experimental observations.

  5. GRASS GIS: The first Open Source Temporal GIS

    Science.gov (United States)

    Gebbert, Sören; Leppelt, Thomas

    2015-04-01

    GRASS GIS is a full featured, general purpose Open Source geographic information system (GIS) with raster, 3D raster and vector processing support[1]. Recently, time was introduced as a new dimension that transformed GRASS GIS into the first Open Source temporal GIS with comprehensive spatio-temporal analysis, processing and visualization capabilities[2]. New spatio-temporal data types were introduced in GRASS GIS version 7, to manage raster, 3D raster and vector time series. These new data types are called space time datasets. They are designed to efficiently handle hundreds of thousands of time stamped raster, 3D raster and vector map layers of any size. Time stamps can be defined as time intervals or time instances in Gregorian calendar time or relative time. Space time datasets are simplifying the processing and analysis of large time series in GRASS GIS, since these new data types are used as input and output parameter in temporal modules. The handling of space time datasets is therefore equal to the handling of raster, 3D raster and vector map layers in GRASS GIS. A new dedicated Python library, the GRASS GIS Temporal Framework, was designed to implement the spatio-temporal data types and their management. The framework provides the functionality to efficiently handle hundreds of thousands of time stamped map layers and their spatio-temporal topological relations. The framework supports reasoning based on the temporal granularity of space time datasets as well as their temporal topology. It was designed in conjunction with the PyGRASS [3] library to support parallel processing of large datasets, that has a long tradition in GRASS GIS [4,5]. We will present a subset of more than 40 temporal modules that were implemented based on the GRASS GIS Temporal Framework, PyGRASS and the GRASS GIS Python scripting library. These modules provide a comprehensive temporal GIS tool set. The functionality range from space time dataset and time stamped map layer management

  6. Differential Impacts of Virus Diversity on Biomass Production of a Native and an Exotic Grass Host.

    Directory of Open Access Journals (Sweden)

    Erin A Mordecai

    Full Text Available Pathogens are common and diverse in natural communities and have been implicated in the success of host invasions. Yet few studies have experimentally measured how pathogens impact native versus exotic hosts, particularly when individual hosts are simultaneously coinfected by diverse pathogens. To estimate effects of interactions among multiple pathogens within host individuals on both transmission of pathogens and fitness consequences for hosts, we conducted a greenhouse experiment using California grassland species: the native perennial grass Nassella (Stipa pulchra, the exotic annual grass Bromus hordeaceus, and three virus species, Barley yellow dwarf virus-PAV, Barley yellow dwarf virus-MAV, and Cereal yellow dwarf virus-RPV. In terms of virus transmission, the native host was less susceptible than the exotic host to MAV. Coinfection of PAV and MAV did not occur in any of the 157 co-inoculated native host plants. In the exotic host, PAV infection most strongly reduced root and shoot biomass, and coinfections that included PAV severely reduced biomass. Infection with single or multiple viruses did not affect biomass in the native host. However, in this species the most potentially pathogenic coinfections (PAV + MAV and PAV + MAV + RPV did not occur. Together, these results suggest that interactions among multiple pathogens can have important consequences for host health, which may not be predictable from interactions between hosts and individual pathogens. This work addresses a key empirical gap in understanding the impact of multiple generalist pathogens on competing host species, with potential implications for population and community dynamics of native and exotic species. It also demonstrates how pathogens with relatively mild impacts independently can more substantially reduce host performance in coinfection.

  7. Breakdown of low-level total petroleum hydrocarbons (TPH) in contaminated soil using grasses and willows.

    Science.gov (United States)

    McIntosh, Patrick; Kuzovkina, Yulia A; Schulthess, Cristian P; Guillard, Karl

    2016-01-01

    A phytoremediation study targeting low-level total petroleum hydrocarbons (TPH) was conducted using cool- and warm-season grasses and willows (Salix species) grown in pots filled with contaminated sandy soil from the New Haven Rail Yard, CT. Efficiencies of the TPH degradation were assessed in a 90-day experiment using 20-8.7-16.6 N-P-K water-soluble fertilizer and fertilizer with molasses amendments to enhance phytoremediation. Plant biomass, TPH concentrations, and indigenous microbes quantified with colony-forming units (CFU), were assessed at the end of the study. Switchgrass grown with soil amendments produced the highest aboveground biomass. Bacterial CFU's were in orders of magnitude significantly higher in willows with soil amendments compared to vegetated treatments with no amendments. The greatest reduction in TPH occurred in all vegetated treatments with fertilizer (66-75%) and fertilizer/molasses (65-74%), followed sequentially by vegetated treatments without amendments, unvegetated treatments with amendments, and unvegetated treatments with no amendment. Phytoremediation of low-level TPH contamination was most efficient where fertilization was in combination with plant species. The same level of remediation was achievable through the addition of grasses and/or willow combinations without amendment, or by fertilization of sandy soil. PMID:26553847

  8. Sequence Analysis of SSR-Flanking Regions Identifies Genome Affinities between Pasture Grass Fungal Endophyte Taxa

    Directory of Open Access Journals (Sweden)

    Eline van Zijll de Jong

    2011-01-01

    Full Text Available Fungal species of the Neotyphodium and Epichloë genera are endophytes of pasture grasses showing complex differences of life-cycle and genetic architecture. Simple sequence repeat (SSR markers have been developed from endophyte-derived expressed sequence tag (EST collections. Although SSR array size polymorphisms are appropriate for phenetic analysis to distinguish between taxa, the capacity to resolve phylogenetic relationships is limited by both homoplasy and heteroploidy effects. In contrast, nonrepetitive sequence regions that flank SSRs have been effectively implemented in this study to demonstrate a common evolutionary origin of grass fungal endophytes. Consistent patterns of relationships between specific taxa were apparent across multiple target loci, confirming previous studies of genome evolution based on variation of individual genes. Evidence was obtained for the definition of endophyte taxa not only through genomic affinities but also by relative gene content. Results were compatible with the current view that some asexual Neotyphodium species arose following interspecific hybridisation between sexual Epichloë ancestors. Phylogenetic analysis of SSR-flanking regions, in combination with the results of previous studies with other EST-derived SSR markers, further permitted characterisation of Neotyphodium isolates that could not be assigned to known taxa on the basis of morphological characteristics.

  9. Natural geo-composites for grassing of eroded and degraded lands

    Directory of Open Access Journals (Sweden)

    Kroumov Victor

    2009-01-01

    Full Text Available Original, natural grass geocomposites (sods were developed on the basis of combination from unstuffy, needle-drive textile material, geo-net and soil-manure-peat or peat with grass cover from grass mixtures. The natural grass geocomposites have the next priorities: quickly grassing and reinforcing of eroded and degraded terrains; large uniformity and compactness of grass cove; long exploiting period; grassing of terrains with big slopes where the mechanization is difficult to use; the articles are with low mass, small thickness and high stability; they limit the growing of weed. The natural grass geocomposites are intend for control of soil erosion and reconstruction of natural landshaft. They can to reinforce ditches, grass collectors, side of the road slopes, as well as lay out lawn, parks, stadiums, ski racing tourist's beauty spot, etc.

  10. Agronomic Management under Organic Farming May Affect the Bioactive Compounds of Lentil (Lens culinaris L. and Grass Pea (Lathyrus communis L.?

    Directory of Open Access Journals (Sweden)

    Valeria Menga

    2014-02-01

    Full Text Available A two year field experiment was carried out to evaluate the effects of three row and eight row seeding on the total phenolic compound (TPC, total flavonoid content (TFC, hydrolyzed (HTC and condensed tannin (CTC, antioxidant activity (ABTS assay, protein content and soluble dietary fiber (SDF and insoluble dietary fiber (IDF in the extracts of lentil (Lens culinaris L. and grass pea (Lathyrus communis L. cultivated under organic farming. The aim of this study was to determine whether row spacing used for seeding in organic farming systems for lentil and grass pea is a suitable method to increase the accumulation of antioxidant compounds in these crops. Grass pea showed the highest mean SDF and protein while lentil varieties showed the greatest and significant content of all of the antioxidant compounds. In lentil, there were increases in TPC (52%, HTC (73%, TFC (85% and CTC (41%, passing from three rows to eight rows, while in grass pea, the increases were lower, and only significant for TFC and CTC (37%, 13% respectively. In both lentils and grass pea, the highest correlation coefficient was between TPC and HTC, which indicates that the HTC includes the predominant phenolic compounds in lentil as well as in grass pea (r = 0.98, 0.71 p < 0.001, respectively. Regardless of legume species, TPC, HTC, TFC and CTC showed significant (p < 0.001 and linear correlations with the ABTS assay. These data confirm the key role of row spacing for the improvement of the antioxidant properties of lentil in organic farming; moreover, they hint at the major responsiveness and adaptation of lentil to environmental stimulus with respect to grass pea.

  11. Climate variability has a stabilizing effect on the coexistence of prairie grasses.

    Science.gov (United States)

    Adler, Peter B; HilleRisLambers, Janneke; Kyriakidis, Phaedon C; Guan, Qingfeng; Levine, Jonathan M

    2006-08-22

    How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of "storage effect" theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. PMID:16908862

  12. A capillary pumping device utilizing super-hydrophobic silicon grass

    International Nuclear Information System (INIS)

    In this study, we show that a compact silicon grass surface can be generated by utilizing the induced coupled plasma method with suitably chosen fabrication parameters. This super-hydrophobic structure suspends deionized water on top of the grass and keeps the contact angle at around 153°. The silicon grass is used to improve the driving efficiency of a capillary pumping micro-duct (without sidewalls), which is completely defined by a bottom hydrophilic stripe (adjacent to a Teflon substrate) and a fully top-covered hydrophobic Teflon surface which is coated on a glass substrate. The channel has a height of 3 µm and a width of 100 µm. In this work, the Teflon substrate is replaced with the silicon grass surface. When the fluid is flowing through the micro-duct on the stripe, the interface between the silicon grass and the hydrophilic stripe forms a stable air cushion barrier to the fluid, thus effectively reducing the frictional force. By changing only the interface with this replacement, we demonstrate that the average measured velocities of the new design show improvements of 21% and 17% in the driving efficiency over the original design for transporting deionized water and human blood, respectively. It is also shown that the measured data of the present design are closer to the values predicted by a theoretical analysis which relates the flow velocity to the contact angles, surface tension and fluid viscosity

  13. [The textual research on the original plant of grass monkshood].

    Science.gov (United States)

    Xie, Jin; Wang, De-Qun

    2012-05-01

    According to the literature review and field investigation, the traditional production areas of the herb grass monkshood are East China, Sichuan and its surroundings. The protophytes of grass monkshood in the east China area are mainly the Huangshan monkshood variant and truppelianum; but in the Sichuan area they are mainly aconite and aconitum hemsleyanum. The above belong to the aconitum of aconitum suby and tendril monkshood. They are the closest genetic relatives and the most evolutive groups as well as the most toxic groups. Local aconite was used as grass monkshood medicine in folk medicine but this happened only in part of the region and for a period of time. There were few records in literature in past dynasties and they would not have been able to be included in mainstream history. It is obviously different from the aconitum kusnezoffii which is stipulated in the pharmacopoeia in past ages. It is not in accordance with history to take kusnezoffii as certified quality grass monkshood and it also has some particular influence on the clinical use of grass monkshood. PMID:22883380

  14. Mismatch in aeroallergens and airborne grass pollen concentrations

    Science.gov (United States)

    Plaza, M. P.; Alcázar, P.; Hernández-Ceballos, M. A.; Galán, C.

    2016-11-01

    An accurate estimation of the allergen concentration in the atmosphere is essential for allergy sufferers. The major cause of pollinosis all over Europe is due to grass pollen and Phl p 5 has the highest rates of sensitization (>50%) in patients with grass pollen-induced allergy. However, recent research has shown that airborne pollen does not always offer a clear indicator of exposure to aeroallergens. This study aims to evaluate relations between airborne grass pollen and Phl p 5 concentrations in Córdoba (southern Spain) and to study how meteorological parameters influence these atmospheric records. Monitoring was carried out from 2012 to 2014. Hirst-type volumetric spore trap was used for pollen collection, following the protocol recommended by the Spanish Aerobiology Network (REA). Aeroallergen sampling was performed using a low-volume cyclone sampler, and allergenic particles were quantified by ELISA assay. Besides, the influence of main meteorological factors on local airborne pollen and allergen concentrations was surveyed. A significant correlation was observed between grass pollen and Phl p 5 allergen concentrations during the pollen season, but with some sporadic discrepancy episodes. The cumulative annual Pollen Index also varied considerably. A significant correlation has been obtained between airborne pollen and minimum temperature, relative humidity and precipitation, during the three studied years. However, there is no clear relationship between allergens and weather variables. Our findings suggest that the correlation between grass pollen and aeroallergen Phl p 5 concentrations varies from year-to-year probably related to a complex interplay of meteorological variables.

  15. The Building of Grass-roots Agricultural Technology Extension System

    Institute of Scientific and Technical Information of China (English)

    Wen; YANG; Jian; HUANG

    2013-01-01

    Based on the survey of 154 farmers in Guiyang City, we analyze the basic situation of building of grass-roots agricultural technology extension system in Guiyang City. Then we point out some problems in the building of grass-roots agricultural technology extension system in Guiyang City: the function of grass-roots agricultural technology extension center weakens; the content of agricultural technology extension is difficult to adapt to farmers’ needs for technology; the extension mode of agricultural technology departments does not adapt to the needs of modern agriculture. In order to perfect the building of grass-roots agricultural technology extension system, the countermeasures and recommendations are put forth as follows: strengthening the input of funds, and ensuring that the basic work of public welfare agricultural technology extension is smoothly carried out; innovating upon the system, and improving the function of grass-roots agricultural technology extension center; implementing management on agricultural technology extension personnel’s performance, and promoting the extension efficiency; strengthening the building of extension team in rural areas, and cultivating high-quality agricultural technology extension personnel; exploring the advanced service mode to meet farmers’ needs.

  16. Een door Nematoden veroorzaakte misvorming van Parapholis strigosa

    NARCIS (Netherlands)

    Polderman, P.J.G.

    1973-01-01

    Specimens of Parapholis strigosa (Dum.) Hubb. collected in a salt-marsh on the Frisian island of Vlieland appeared to be infected by a nematod worm, probably Anguina agrostis (Steinb.). This parasite causes swelling of the ovaries of grasses. No earlier records of Anguina agrostis on Parapholis stri

  17. Growth responses of maritime sand dune plant species to arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Mariusz Tadych

    2014-08-01

    Full Text Available In a pot experiment conducted in a greenhouse, the response of 6 plant species dominating in the succession of vegetation of a deflation hollow of the Łeba Bar to inoculation with arbuscular mycorrhizal fungi (AMF was investigated. The inoculum was a mixture of soil, roots and spores of 5 species of AMF with the dominant species Glomus aggregatum. Except for Corynephorus canescens and Festuca rubra subsp. arenaria, both the growth and the dry matter of above-ground parts of plants of Agrostis stolonifera, Ammophila arenaria, Corynephorus canescens, Juncus articulatus and J. balticus inoculated with AMF were higher than those growing in soils lacking infection propagules of these fungi. Inoculation with AMF decreased the dry matter of root: shoot ratios in 5 plant species. This property was not determined in Festuca rubra subsp. arenaria due to the death of all control plants. The level of mycorrhizal infection was low and did not correlate with the growth responses found. The high growth reaction of Juncus spp. to AMF found in this study suggests that the opinion of non-mycotrophy or low dependence of plants of Juncaceae on AMF was based on results of investigations of plants growing in wet sites known to inhibit the formation of mycorrhizae.

  18. Analysis of two heterologous flowering genes in ¤Brachypodium distachyon¤ demonstrates its potential as a grass model plant

    DEFF Research Database (Denmark)

    Olsen, P.; Lenk, I.; Jensen, Christian S.;

    2006-01-01

    date up to 10 weeks in plants of the T, generation. Furthermore, a positive correlation between Terminal Flower 1 expression level and delay in heading date was apparent for most of the lines. The short life cycle and fast transformation system of B. distachyon allowed heading date analyses in the T-1......Despite the great contribution of model organisms, such as Arabidopsis and rice to understand biological processes in plants, these models are less valuable for functional studies of particular genes from temperate grass crop species. Therefore a new model plant is required, displaying features...... including close phylogenetic relationship to the temperate grasses, vernalisation requirement, high transformation efficiency, small genome size and a rapid life cycle. These requirements are all fulfilled by the small annual grass Brachypodium distachyon. As a first step towards implementing this plant as...

  19. EFFECT OF DROUGHT STRESS AND ADDITION OF ARBUSCULA MYCORRHIZAL FUNGI (AMF ON GROWTH AND PRODUCTIVITY OF TROPICAL GRASSES (Chloris gayana, Paspalum dilatatum, and Paspalum notatum

    Directory of Open Access Journals (Sweden)

    Pebriansyah A

    2014-06-01

    Full Text Available Grasses productivity is affected by soil water availability. Arbuscular Mycorrhizal Fungi (AMF was innoculated to support plant to overcome drought stress during its growth. The aim of this study was to understand the role of  Arbuscular Mycorrhizal Fungi (AMF to support growth and the production of grasses in drought stress condition. Three species of tropical grasses : Chloris    gayana,    Paspalum    notatum,    and  Paspalum dilatatum were used. The research used completely randomized design with 4 treatments consisting of M0S0 = without AMF and daily watering, M0S1 = without AMF and without watering; M1S0 = with mycorrhiza and daily watering; M1S1 = with AMF and without watering. and 5 replications. The four treatments research were as follows; Each type of grasses were obsereved in a separate study. The result showed that AMF played significant role in improving growth and root dry weight biomass of Chloris    gayana in drought condition. Paspalum notatum is the most adaptive grass in the drought condition. Chloris gayana has the growth and a better production than Paspalum dilatatum.

  20. Enchytraeids as indicator of soil quality in temporary organic grass-clover leys under contrasting management

    DEFF Research Database (Denmark)

    Maraldo, Kristine; Schmelz, Rüdiger; Larsen, Thomas;

    2015-01-01

    interactions among soil physical, chemical and biological properties suggest that enchytraeid abundance is not a feasible stand-alone indicator of management impacts on soil quality in temporary grass-clover leys but may candidate as one of several biological key parameters in more comprehensive soil quality...... subject to contrasting management regimes (cutting, slurry injection, grazing). Enchytraeid density, biomass and species composition was determined in 0–18 cm soil sampled in October, and again in March and May before and after slurry application, respectively. For soils retrieved in October, ley age had...... than in the spring, regardless of management regime. Compared with leys used for cutting, grazed leys had consistently lower enchytraeid density and biomass. This was ascribed to soil compaction induced by heifer trampling. The number of species ranged from 11 to 18 in the autumn and from 7 to 13...

  1. Genetic and cytogenetic structure of wild lemon grass (Elionurus muticus populations

    Directory of Open Access Journals (Sweden)

    Thanise Nogueira Füller

    2015-12-01

    Full Text Available Elionurus muticus is a native aromatic grass from the Pampa biome that produces an essential oil that is rich in citral. Despite the importance of citral, few studies have examined this species. The aims of this work were to evaluate the genetic structure and to characterize cytogenetically natural populations collected from Brazil. Genetic characterization was performed using AFLP markers, and cytogenetics assessed the chromosome number, karyotype and meiosis. The studied populations had genetic variability, especially within populations, indicating the possibility of selecting plants with relevant characters. High variability also suggests the preferential occurrence of outcrossing in natural populations. Regular meiosis was observed in the cytogenetic analysis with chromosome number 2n=20. The karyotype of the species is presented for the first time, with the karyotype formula 3sm + 4a + 1saSAT.

  2. Isolation and Characterization of Microsatellite Loci for a Bioenergy Grass, Miscanthus sacchariflorus (Poaceae

    Directory of Open Access Journals (Sweden)

    Hai-Fei Zhou

    2013-01-01

    Full Text Available Premise of the study: Microsatellite loci were developed for the biomass C4 grass, Miscanthus sacchariflorus, and proved to be suitable markers for population genetic studies and germplasm management of this species. Methods and Results: Twenty-three polymorphic microsatellite loci were identified from an enriched genomic library of M. sacchariflorus. The polymorphism was assessed in 50 individuals from two populations in China. The number of alleles per locus varied from two to 18, with a mean of 8.13. The observed and expected heterozygosities ranged from 0.2 to 1.0 and from 0.198 to 0.898, respectively. Conclusions: These new markers will be useful for further investigation of genetic diversity and population genetic structure as well as molecular breeding of Miscanthus species.

  3. Elevated atmospheric CO2 triggers compensatory feeding by root herbivores on a C3 but not a C4 grass.

    Directory of Open Access Journals (Sweden)

    Scott N Johnson

    Full Text Available Predicted increases in atmospheric carbon dioxide (CO2 concentrations often reduce nutritional quality for herbivores by increasing the C:N ratio of plant tissue. This frequently triggers compensatory feeding by aboveground herbivores, whereby they consume more shoot material in an attempt to meet their nutritional needs. Little, however, is known about how root herbivores respond to such changes. Grasslands are particularly vulnerable to root herbivores, which can collectively exceed the mass of mammals grazing aboveground. Here we provide novel evidence for compensatory feeding by a grass root herbivore, Sericesthis nigrolineata, under elevated atmospheric CO2 (600 µmol mol(-1 on a C3 (Microlaena stipoides but not a C4 (Cymbopogon refractus grass species. At ambient CO2 (400 µmol mol(-1 M. stipoides roots were 44% higher in nitrogen (N and 7% lower in carbon (C concentrations than C. refractus, with insects performing better on M. stipoides. Elevated CO2 decreased N and increased C:N in M. stipoides roots, but had no impact on C. refractus roots. Root-feeders displayed compensatory feeding on M. stipoides at elevated CO2, consuming 118% more tissue than at ambient atmospheric CO2. Despite this, root feeder biomass remained depressed by 24%. These results suggest that compensatory feeding under elevated atmospheric CO2 may make some grass species particularly vulnerable to attack, potentially leading to future shifts in the community composition of grasslands.

  4. The complete chloroplast genome sequence of Brachypodium distachyon: sequence comparison and phylogenetic analysis of eight grass plastomes

    Directory of Open Access Journals (Sweden)

    Anderson Olin D

    2008-07-01

    Full Text Available Abstract Background Wheat, barley, and rye, of tribe Triticeae in the Poaceae, are among the most important crops worldwide but they present many challenges to genomics-aided crop improvement. Brachypodium distachyon, a close relative of those cereals has recently emerged as a model for grass functional genomics. Sequencing of the nuclear and organelle genomes of Brachypodium is one of the first steps towards making this species available as a tool for researchers interested in cereals biology. Findings The chloroplast genome of Brachypodium distachyon was sequenced by a combinational approach using BAC end and shotgun sequences derived from a selected BAC containing the entire chloroplast genome. Comparative analysis indicated that the chloroplast genome is conserved in gene number and organization with respect to those of other cereals. However, several Brachypodium genes evolve at a faster rate than those in other grasses. Sequence analysis reveals that rice and wheat have a ~2.1 kb deletion in their plastid genomes and this deletion must have occurred independently in both species. Conclusion We demonstrate that BAC libraries can be used to sequence plastid, and likely other organellar, genomes. As expected, the Brachypodium chloroplast genome is very similar to those of other sequenced grasses. The phylogenetic analyses and the pattern of insertions and deletions in the chloroplast genome confirmed that Brachypodium is a close relative of the tribe Triticeae. Nevertheless, we show that some large indels can arise multiple times and may confound phylogenetic reconstruction.

  5. Lemon grass oil for improvement of oral health

    Directory of Open Access Journals (Sweden)

    Ruckmani Rajesvari

    2013-01-01

    Full Text Available Lemon grass essential oil has been used for decades to treat respiratory infections, sinusitis, bladder infections, high cholesterol, digestive problem, varicose veins and also for regeneration of connective tissue. It has anti spasmodic, anti-pyretic, anti-fungal, anti-bacterial, anti-inflammatory, anti-septic, insect repellent, sedative, vasodilator and flavoring properties. In china, it has been used traditionally as a remedy for stomach and liver diseases and also to treat rheumatism. Since lemon grass oil possess various pharmacological actions, it is also quite useful in dentistry. Hence, the objective of this article is to highlight various uses of lemon grass oil in the dental field and in the medical field in order to aid the professionals for future research.

  6. Grasses – a potential sustainable resource for biocrude production

    DEFF Research Database (Denmark)

    Grigoras, Ionela; Rosendahl, Lasse Aistrup; Toor, Saqib Sohail;

    /ha) are mapped as function of the type of grassland area (permanent, roadside, grass sown in crop rotation systems) using 2012 databases made available by Jordbrugs Analyser Portal and Danmarks Miljøportal. Grasses have become a promising lignocellulosic biomass for biofuels production due to the low cost...... factor and lack of competition with food crops. They can be used as whole input, or as a residue after protein extraction. In order to determine the production potential of biofuels based on HtL conversion and to establish at the same time the optimum conditions for the HtL process that could lead to a......This study aims to map the spatial distribution of different types of grasses available in Denmark using a GIS (Geographical Information System) based approach and to supplement these with biofuel potential maps based on HtL conversion. Biomass yields (t/ha) and biofuel energy equivalent (GJ...

  7. Forage supply in thinned Caatinga enriched with buffel grass (Cenchrus ciliaris L. grazed by goats and sheep - doi: 10.4025/actascianimsci.v34i2.12548

    Directory of Open Access Journals (Sweden)

    Diogo da Costa Soares

    2012-03-01

    Full Text Available Forage supply from herbs was assessed in a thinned Caatinga enriched with buffel grass (Cenchrus ciliaris L. exposed to goat and sheep grazing. The 2.4 ha experimental area, located at the Experimental Station of the Federal University of Campina Grande, in Santa Terezinha, Paraíba State, Brazil, was divided into four 0.6 ha paddocks, which were further subdivided into two 0.3 ha experimental plots. Twelve F1 (Boer x SRD goats and 12 Santa Inês sheep were divided in four groups of six animals of the same species. The herbaceous vegetation was separated into buffel grass (Cenchrus ciliaris L., dicotyledons and other grass species. Treatments were randomized to plots according to a completely random design with two treatments, four replications, with measures repeated in time (July/1, Aug/1, Sept/1 and Oct/1. Buffel grass dry mater (DM availability was higher in the sheep grazed than in the goat-grazed area. Buffel grass DM supply did not change from July to September, while dicotyledons DM supply decreased. Grazing affected availability, accumulation rate and supply of the forage produced (DM basis by dicotyledonous herbs. Buffel grass forage availability was not affected during the experimental period.

  8. INFLUENCE OF SEWAGE SLUDGE ON THE CHOSEN SOIL PROPERTIES AND MICROBIOLOGICAL PARAMETERS OF URBAN GRASS MIXTURES RHIZOSPHERE

    Directory of Open Access Journals (Sweden)

    Urszula Wydro

    2014-12-01

    Full Text Available The aim of this study was to analyse the influence of municipal sewage sludge on selected microbiological parameters in the rhizosphere of lawn grass mixtures. Four experiments on the lawns along the main roads of Bialystok were founded. The factors in the experiment were three doses of sewage sludge (0 – control; 7.5 and 15 kg·m-2 and two grass mixtures (Eko and Roadside. The studied parameters were monitored twice during 2011 vegetation season by determining the total number of soil microorganisms, the total number of Gram-negative bacteria, the number of bacteria of Pseudomonas fluorescens species, the number of amylolytic and proteolytic bacteria. Sewage sludge amended to soil resulted in a change of physical-chemical properties of soil. The sewage sludge application to soil influenced significantly the number of proteolytic and Gram-negative bacteria.

  9. Variations of Roughness Coefficients with Flow Depth of Grassed Swale

    Science.gov (United States)

    Mustaffa, N.; Ahmad, N. A.; Razi, M. A. M.

    2016-07-01

    Grassed swales are the best management practice (BMP), which has been widely used to reduce the peak flow, reduce water pollution through vegetated filtration, and improve the groundwater recharge. Universiti Tun Hussein Onn Malaysia (UTHM) is using the approach of grassed swales recommended by the Department of Irrigation and Drainage Malaysia (DID) for reducing the risk of flooding and controlling the water pollution. This paper investigates the variations of roughness coefficients with the flow depth of grassed swales in the campus of UTHM. Fieldwork was carried out on the grassed swale to collect the hydraulic data, which including the levelling work, measuring the flow depth and flow velocity of the swale. The flow depth of swale was taken at three points divided along the width of swale and the flow velocity is captured three times at each of the point. The variations of roughness coefficients of grassed swales are presented in Manning's equation, and the results reveal that the n value increases with the increasing of flow depth. Manning's coefficient value found in this study is in the range of 0.110 to 0.756, which are higher than the value proposed by the Urban Stormwater Management Manual for Malaysia (MSMA). The relationships of flow depth and velocity at each section of the swale are portrayed in graphs, which show that the velocity increases with the decreasing of flow depth. The outcomes of this study can be concluded that the variation of Manning's coefficient value is influenced by the swale profile, flow depth, flow velocity, and as well as the vegetation used in the grassed swale concerned.

  10. Interspecific sex in grass smuts and the genetic diversity of their pheromone-receptor system.

    Directory of Open Access Journals (Sweden)

    Ronny Kellner

    2011-12-01

    Full Text Available The grass smuts comprise a speciose group of biotrophic plant parasites, so-called Ustilaginaceae, which are specifically adapted to hosts of sweet grasses, the Poaceae family. Mating takes a central role in their life cycle, as it initiates parasitism by a morphological and physiological transition from saprobic yeast cells to pathogenic filaments. As in other fungi, sexual identity is determined by specific genomic regions encoding allelic variants of a pheromone-receptor (PR system and heterodimerising transcription factors. Both operate in a biphasic mating process that starts with PR-triggered recognition, directed growth of conjugation hyphae, and plasmogamy of compatible mating partners. So far, studies on the PR system of grass smuts revealed diverse interspecific compatibility and mating type determination. However, many questions concerning the specificity and evolutionary origin of the PR system remain unanswered. Combining comparative genetics and biological approaches, we report on the specificity of the PR system and its genetic diversity in 10 species spanning about 100 million years of mating type evolution. We show that three highly syntenic PR alleles are prevalent among members of the Ustilaginaceae, favouring a triallelic determination as the plesiomorphic characteristic of this group. Furthermore, the analysis of PR loci revealed increased genetic diversity of single PR locus genes compared to genes of flanking regions. Performing interspecies sex tests, we detected a high potential for hybridisation that is directly linked to pheromone signalling as known from intraspecies sex. Although the PR system seems to be optimised for intraspecific compatibility, the observed functional plasticity of the PR system increases the potential for interspecific sex, which might allow the hybrid-based genesis of newly combined host specificities.

  11. Functional characterization of a plasma membrane Na+/H+ antiporter from alkali grass (Puccinellia tenuiflora).

    Science.gov (United States)

    Wang, Xin; Yang, Ru; Wang, Baichen; Liu, Guifeng; Yang, Chuanping; Cheng, Yuxiang

    2011-10-01

    We have cloned a Na(+)/H(+) antiporter gene (GenBank accession no EF440291, PtNHA1) from Puccinellia tenuiflora (so-called alkali grass in Chinese) roots under NaCl salt stress. Its cDNA is 3775 bp and contains a 3414 bp open reading frame. The amino acid sequences of PtNHA1 show high identities with a putative plasma membrane Na(+)/H(+) antiporter from wheat. PtNHA1 was predicted to contain 11 hypothetical transmembrane domains in the N-terminal part and to localize in the plasma membrane. Genomic DNA gel blot analysis shows that PtNHA1 is a single-copy gene in the alkali grass genome. PtNHA1 is highly expressed in leaves, roots and shoots by RNA gel blot analysis. Furthermore, PtNHA1 gene expression of alkali grass was clearly up-regulated by NaCl salt stress. Overexpression of PtNHA1 in Arabidopsis resulted in enhanced tolerance of transgenic plants to NaCl stress. The ion contents analysis shows that, compared with the wild-type (WT), less Na(+) and more K(+) were accumulated in transgenic plants under NaCl stress. The results indicate that PtNHA1 play an important role in NaCl salt stress. Additionally, compared with the WT, total activities of ascorbate peroxidase (APX) and catalase (CAT), two key reactive oxygen species (ROS) detoxifying enzymes were high in transgenic plants under salt stress, respectively. The transcript levels of two APX genes (Apx1, s/mApx) and two CAT genes (Cat1, Cat2) in transgenic plants were higher than those in WT. This suggests that overexpression of PtNHA1 results in enhanced ROS-scavenging enzymes of transgenic plants under NaCl salt stress.

  12. The Emergence of Grass Root Chemical Ecology

    Science.gov (United States)

    This paper is an invited commentary on a paper to be published in this journal on the discovery of m-tyrosine as a potent allelochemical. Allelochemicals are natural herbicides produced by one type of plant to better compete with other plant species. In my commentary, I discuss the significance of...

  13. Production of N2O in grass-clover pastures

    OpenAIRE

    Thyme, Mette; Ambus, Per

    2002-01-01

    In organic as well as conventional dairy farming, grass-clover pastures is an important component of the cropping system. This is because grass-clover is an excellent cattle fodder, and because clover has the ability of fixing atmospheric N2. When budgets for N2O emissions are made accord-ing to the IPCC guidelines it is assumed that 1.25 % of added nitrogen is emitted as N2O. This emission factor is used for all nitrogen inputs although the factor relies on experiments with fertilizer and ma...

  14. Gasification of corn and clover grass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Pedro D' Jesus; Nikolaos Boukis; Bettina Kraushaar-Czarnetzki; Eckhard Dinjus [Chemisch-Physikalische Verfahren (ITC-CPV), Forschungszentrum Karlsruhe (Germany). Institut fuer Technische Chemie

    2006-05-15

    The influence of pressure, temperature, residence time, and alkali addition on the gasification of corn starch, clover grass and corn silage in supercritical water was investigated. Changing the pressure did not alter the gasification yield. An increase in the temperature notably improved the conversion of biomass. Residence time variations revealed that with longer residence time, gasification yield was improved until a maximum was reached. Gas composition changed with residence time and temperature. Potassium addition affected the gasification yield of corn starch, but did not influence the gasification yield of the potassium-containing natural products of clover grass and corn silage. 22 refs., 5 figs., 3 tabs.

  15. Production of N2O in grass-clover pastures

    OpenAIRE

    Carter, Mette S.

    2005-01-01

    Agricultural soils are known to be a considerable source of the strong greenhouse gas nitrous oxide (N2O), and in soil N2O is mainly produced by nitrifying and denitrifying bacteria. In Denmark, grass-clover pastures are an important component of the cropping system in organic as well as conventional dairy farming, and on a European scale grass-clover mixtures represent a large part of the grazed grasslands. Biological dinitrogen (N2) fixation in clover provides a major N input to these syste...

  16. Effect of toasting field beans and of grass-clover

    DEFF Research Database (Denmark)

    Mogensen, Lisbeth; Vestergaard, Jannie Steensig; Fretté, Xavier;

    2010-01-01

    The effect of toasting field beans and of grass-clover: maize silage ratio on milk production, milk composition and the sensory quality of the milk was investigated in a 2   2 factorial experiment. Toasting of field beans resulted in lower milk contents of both fat (44.2 versus 46.1 g/kg, P = 0...... sensory characteristics. Increasing the proportion of maize silage at the expense of grass-clover silage did not affect milk production, but decreased the milk content of long-chain fatty acids, as well as the content of carotenes...

  17. Weed species diversity in organic and integrated farming systems

    Directory of Open Access Journals (Sweden)

    Magdalena Jastrzębska

    2013-10-01

    Full Text Available Phytosociological data were collected in 1994–1996 in plots (relevés at the Research Station for Organic Farming and Conservation Breeding of the Polish Academy of Sciences in Popielno included in a large-area experiment conducted according to the concept and method proposed by Prof. S. Nawrocki. In a four-field crop rotation (root crops – spring barley undersown with red clover and grasses – red clover/grass mixture – winter triticale, each field was divided into two management units, organic and integrated. Data were collected in relevés by the Braun-Blanquet method, each year at the peak of the growing season. Weed abundance (% cover in cultivated fields and the number of weed species (species richness in crops were determined, which provided a basis for calculating the Shannon-Wiener indices of species diversity and evenness, and the Rényi profiles. The qualitative (species and quantitative structure of weed communities was compared using the Sørensen index. A total of 115 weed taxa (species, subspecies and varieties were identified in the examined agro-phytocenoses. Echinochloa crus-galli, Chenopodium album, Matricaria maritima subsp. inodora, Capsella bursa-pastoris, Thlaspi arvense and Stellaria media were the most abundant. Weed infestation was slightly higher in the organic farming system than in the integrated system. Organic farming contributed to higher weed species diversity in root crops, red clover/grass mixtures and winter triticale. Weed species richness was reduced in red clover/grass stands, while root crops and – to a lesser degree – spring barley undersown with red clover and grasses decreased weed species diversity. The species composition and in particular the quantitative structure of weeds were affected by crop species and cultivation regime rather than by the farming system. Weed communities of crops grown under organic and integrated farming systems were more similar with regard to species composition

  18. Leaf cold acclimation and freezing injury in C3 and C4 grasses of the Mongolian Plateau.

    Science.gov (United States)

    Liu, Mei-Zhen; Osborne, Colin P

    2008-01-01

    The scarcity of C4 plants in cool climates is usually attributed to their lower photosynthetic efficiency than C3 species at low temperatures. However, a lower freezing resistance may also decrease the competitive advantage of C4 plants by reducing canopy duration, especially in continental steppe grasslands, where a short, hot growing season is bracketed by frost events. This paper reports an experimental test of the hypothesis that cold acclimation is negligible in C4 grasses, leading to greater frost damage than in C3 species. The experiments exposed six C3 and three C4 Mongolian steppe grasses to 20 d chilling or control pre-treatments, followed by a high-light freezing event. Leaf resistance to freezing injury was independent of photosynthetic type. Three C3 species showed constitutive freezing resistance characterized by 95% leaf mortality after the freezing event. However, three C3 and two C4 species displayed a cold acclimation response, showing significant decreases in osmotic potential and photosynthesis after exposure to chilling, and a 30-72% reduction of leaf freezing injury. This result suggested that down-regulation of osmotic potential may be involved in the cold acclimation process, and demonstrated that there is no inherent barrier to the development of cold acclimation in C4 species from this ecosystem. Cold acclimation via osmoregulation represents a previously undescribed mechanism to explain the persistence of C4 plants in cool climates. PMID:18980952

  19. Soil C storage and greenhouse gas emission perennial grasses managed for bio energy feedstock

    Science.gov (United States)

    Perennial grasses like switchgrass or big bluestem when managed as bioenergy feedstock require nitrogenous inputs. Nitrogen fertilizer frequently cause nitrous oxide emission. Therefore, managing grasses as feedstock may reduce the greenhouse gas (GHG) mitigation potential expected from perennial. ...

  20. Compatibility, Yield, and Quality of Matua Prairie Grass, Bromus Willdenowii (Kunth), With Legumes.

    OpenAIRE

    Guay, Jennifer Fincham

    2001-01-01

    Matua prairie grass has a potential to extend the grazing season in Virginia due to its higher early spring and fall production. However, little is known about the compatibility of Matua prairie grass with legumes or the effects of legumes on the yield and quality of Matua prairie grass/legume mixtures. An experiment was conducted in 1998 and 1999 to investigate the botanical composition, yield, and chemical composition of Matua prairie grass grown with legumes. Legume treatments consistin...

  1. Rehabilitation with forage grasses of an area degraded by urban solid waste deposits

    OpenAIRE

    Vanessa Soares Miranda; Karina Guimarães Ribeiro; Alexandre Christófaro Silva; Rosana Cristina Pereira; Odilon Gomes Pereira; Pablo Vidal Torrado; José Sebastião Cunha Fernandes; Maxwel Coura Oliveira

    2012-01-01

    Dry matter yield and chemical composition of forage grasses harvested from an area degraded by urban solid waste deposits were evaluated. A split-plot scheme in a randomized block design with four replicates was used, with five grasses in the plots and three harvests in the subplots. The mineral content and extraction and heavy metal concentration were evaluated in the second cut, using a randomized block design with five grasses and four replicates. The grasses were Brachiaria decumbens cv. ...

  2. Neurotoxicity of mycotoxins produced in vitro by Penicillium roqueforti isolated from maize and grass silage.

    Science.gov (United States)

    Malekinejad, H; Aghazadeh-Attari, J; Rezabakhsh, A; Sattari, M; Ghasemsoltani-Momtaz, B

    2015-10-01

    Fungal growth in human foods and animal feeds causes profound damage indicating a general spoilage, nutritional losses, and the formation of mycotoxins. Thirty apparently contaminated maize and grass silage samples were analyzed for the presence of total fungi. Penicillium roqueforti were isolated from all (100%) moldy silage samples on general and selective culture media. Furthermore, P. roqueforti-positive samples culture media subjected to the toxin extraction and toxins of patulin, penicillic acid, mycophenolic acid, and roquefortin-C (ROQ-C) were identified by means of high-performance liquid chromatography method. Cytotoxicity of identified toxins was investigated on neuro-2a cells. Alamar blue reduction, neutral red uptake, and intracellular adenosine triphosphate (ATP) content assays indicated that patulin and ROQ-C exert the strongest and weakest toxicity, respectively. Reactive oxygen species (ROS) generation by the toxins-exposed cells was measured, and the results supported the mitochondrial and lysosomal dysfunction and ATP depletion in exposed cells. Our data suggest that P. roqueforti is the widely present mold in analyzed maize and grass silage samples, which is able to produce toxins that cause neurotoxicity. This finding may explain in part some neuronal disorders in animals, which are fed contaminated feedstuffs with mentioned fungus. Moreover, mitochondrial and lysosomal dysfunction, intracellular ATP depletion, and the excessive ROS generation were found as the mechanisms of cytotoxicity for P. roqueforti-produced toxins.

  3. Grasses suppress shoot-borne roots to conserve water during drought.

    Science.gov (United States)

    Sebastian, Jose; Yee, Muh-Ching; Goudinho Viana, Willian; Rellán-Álvarez, Rubén; Feldman, Max; Priest, Henry D; Trontin, Charlotte; Lee, Tak; Jiang, Hui; Baxter, Ivan; Mockler, Todd C; Hochholdinger, Frank; Brutnell, Thomas P; Dinneny, José R

    2016-08-01

    Many important crops are members of the Poaceae family, which develop root systems characterized by a high degree of root initiation from the belowground basal nodes of the shoot, termed the crown. Although this postembryonic shoot-borne root system represents the major conduit for water uptake, little is known about the effect of water availability on its development. Here we demonstrate that in the model C4 grass Setaria viridis, the crown locally senses water availability and suppresses postemergence crown root growth under a water deficit. This response was observed in field and growth room environments and in all grass species tested. Luminescence-based imaging of root systems grown in soil-like media revealed a shift in root growth from crown-derived to primary root-derived branches, suggesting that primary root-dominated architecture can be induced in S. viridis under certain stress conditions. Crown roots of Zea mays and Setaria italica, domesticated relatives of teosinte and S. viridis, respectively, show reduced sensitivity to water deficit, suggesting that this response might have been influenced by human selection. Enhanced water status of maize mutants lacking crown roots suggests that under a water deficit, stronger suppression of crown roots actually may benefit crop productivity. PMID:27422554

  4. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Directory of Open Access Journals (Sweden)

    Michael A Steinwand

    Full Text Available Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines.

  5. Brachypodium sylvaticum, a model for perennial grasses: transformation and inbred line development.

    Science.gov (United States)

    Steinwand, Michael A; Young, Hugh A; Bragg, Jennifer N; Tobias, Christian M; Vogel, John P

    2013-01-01

    Perennial species offer significant advantages as crops including reduced soil erosion, lower energy inputs after the first year, deeper root systems that access more soil moisture, and decreased fertilizer inputs due to the remobilization of nutrients at the end of the growing season. These advantages are particularly relevant for emerging biomass crops and it is projected that perennial grasses will be among the most important dedicated biomass crops. The advantages offered by perennial crops could also prove favorable for incorporation into annual grain crops like wheat, rice, sorghum and barley, especially under the dryer and more variable climate conditions projected for many grain-producing regions. Thus, it would be useful to have a perennial model system to test biotechnological approaches to crop improvement and for fundamental research. The perennial grass Brachypodiumsylvaticum is a candidate for such a model because it is diploid, has a small genome, is self-fertile, has a modest stature, and short generation time. Its close relationship to the annual model Brachypodiumdistachyon will facilitate comparative studies and allow researchers to leverage the resources developed for B. distachyon. Here we report on the development of two keystone resources that are essential for a model plant: high-efficiency transformation and inbred lines. Using Agrobacterium tumefaciens-mediated transformation we achieved an average transformation efficiency of 67%. We also surveyed the genetic diversity of 19 accessions from the National Plant Germplasm System using SSR markers and created 15 inbred lines. PMID:24073248

  6. Evolution of the defensin-like gene family in grass genomes

    Indian Academy of Sciences (India)

    Jiandong Wu; Xiaolei Jin; Yang Zhao; Qing Dong; Haiyang Jiang; Qing Ma

    2016-03-01

    Plant defensins are small, diverse, cysteine-rich peptides, belonging to a group of pathogenesis-related defense mechanism proteins, which can provide a barrier against a broad range of pathogens. In this study, 51 defensin-like (DEFL) genes in Gramineae, including brachypodium, rice, maize and sorghum were identified based on bioinformatics methods. Using the synteny analysis method, we found that 21 DEFL genes formed 30 pairs of duplicated blocks that have undergone large-scale duplication events, mostly occurring between species. In particular, some chromosomal regions are highly conserved in the four grasses. Using mean s values, we estimated the approximate time of divergence for each pair of duplicated regions and found that these regions generally diverged more than 40 million years ago (Mya). Selection pressure analysis showed that the DEFL gene family is subjected to purifying selection. However, sliding window analysis detected partial regions of duplicated genes under positive selection. The evolutionary patterns within DEFL gene families among grasses can be used to explore the subsequent functional divergence of duplicated genes and to further analyse the antimicrobial effects of defensins during plant development.

  7. Digestion and nitrogen metabolism of grass fed dairy cows.

    NARCIS (Netherlands)

    Vuuren, van A.M.

    1993-01-01

    Until recently, young, highly digestible grass was considered an ideal feed for dairy cows. However, research during the last decades has shown that the nutrient supply of grazing animals is insufficient for milk productions above c. 29 kg per day. Experiments in England and New Zealand have shown t

  8. Snakes in the Grass: Weaving Success for Everyone.

    Science.gov (United States)

    Ide, Janet L.

    2000-01-01

    Describes "Snakes in the Grass," a weaving project used with special needs students. Discusses the preliminary skill-building activities used, the process for creating the students' individual snakes, and the preparation and process for how the students wove the snakes. (CMK)

  9. Theoretical versus Grass-Roots Development of a Community Partnership

    Science.gov (United States)

    Escandon, Socorro

    2010-01-01

    The purpose of this qualitative study was to examine Bracht, Kingbury, and Rissel's five-stage community development model as applied to a grass-roots community action group. The sample consisted of low-income, predominantly Hispanic women in a community action group in a Southwestern barrio, some of whom were experiencing domestic violence. The…

  10. Wave overtopping resistance of grassed slopes in Viet Nam

    NARCIS (Netherlands)

    Trung, L.H.; Verhagen, H.J.; Van der Meer, J.W.

    2011-01-01

    The Simulator was applied to test the resistance against wave overtopping of grass covered dike slopes in Viet Nam. Observation and measurement during destructive tests were performed to investigate the development process of damage induced by overtopping flow. Damages were likely to be initiated at

  11. The potential of C4 grasses for cellulosic biofuel production

    NARCIS (Netherlands)

    Weijde, van der R.T.; Alvim Kamei, C.L.; Torres Salvador, A.F.; Vermerris, W.; Dolstra, O.; Visser, R.G.F.; Trindade, L.M.

    2013-01-01

    With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potent

  12. Sewage treatment with constructed wetland using panicum maximum forage grass

    Directory of Open Access Journals (Sweden)

    B. L. Chavan

    2012-10-01

    Full Text Available Panicum maximum Jacq (Guinea grass is an important multicut forage grass with ease of propagation, fast growth available at local level and high quality forage for livestock. This grass is a biotic resource, due to its several properties grass. It is used for wastewater treatment by Phytoremediation (Root Zone technology through constructed wetland. In the present investigation, Panicum maximum was used for the treatment of sewage, because of its highest growth near sewage disposal areas. Designed Angular Horizontal Subsurface type constructed wetland for the treatment of sewage was used for recycling and reuses. The samples of sewage with different dilutions viz. 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% were tested for the treatment. Results reveal that pH range was changed from 6.79 to 7.10, maximum reduction of E.C was 25.14 % at 80%, TSS by 48.70%, TDS by 55.73 %, TS by 54.31 %, COD by 61.05 %, BOD by 59.25 %, NO3 by 69.32%, PO4 by 48.10% and SO4 by 41.48% respectively. The colour and odour were removed resulting into clear water.

  13. Colonization of torrefied grass fibers by plant beneficial microorganisms

    NARCIS (Netherlands)

    Trifonova, R.D.; Babini, V.; Postma, J.; Ketelaars, J.J.M.H.; Elsas, van J.D.

    2009-01-01

    This study aimed to assess the colonization of thermally treated (i.e. torrefied) grass fibers (TGFs), a new prospective ingredient of potting soil. Eleven bacterial strains and one fungus, Coniochaeta ligniaria F/TGF15, all isolated from TGF or its extract after inoculation with a soil microbial co

  14. Colonization of torrefied grass fibers by plant-beneficial microorganisms

    NARCIS (Netherlands)

    Trifonova, R.; Babini, V.; Postma, J.; Ketelaars, J.J.M.H.; van Elsas, J.D.

    2009-01-01

    This study aimed to assess the colonization of thermally treated (i.e. torrefied) grass fibers (TGFs), a new prospective ingredient of potting soil. Eleven bacterial strains and one fungus, Coniochaeta ligniaria F/TGF15, all isolated from TGF or its extract after inoculation with a soil microbial co

  15. The Sorghum bicolor genome and the diversification of grasses

    Science.gov (United States)

    Sorghum, an African grass related to sugar cane and maize, is grown for food, feed, fiber and fuel. We present an initial analysis of the 730-megabase Sorghum bicolor (L.) Moench genome, placing 98% of genes in their chromosomal context using whole-genome shotgun sequence validated by genetic, phy...

  16. Rainbows in the grass. II. Arbitrary diagonal incidence.

    Science.gov (United States)

    Adler, Charles L; Lock, James A; Fleet, Richard W

    2008-12-01

    We consider external reflection rainbow caustics due to the reflection of light from a pendant droplet where the light rays are at an arbitrary angle with respect to the horizontal. We compare this theory to observation of glare spots from pendant drops on grass; we also consider the potential application of this theory to the determination of liquid surface tension. PMID:19037345

  17. Translational Biology: From Arabidopsis Flowers to Grass Inflorescence Architecture

    Science.gov (United States)

    One of the key events in plant development is the initiation of lateral organs from the flanks of the meristem. In grasses, the inflorescence meristem (IM) reiteratively initiates a series of lateral meristems with slightly different fates. Our understanding of the genes and networks that regulate g...

  18. Grass Roots: African Origins of an American Art

    OpenAIRE

    E. N. Anderson

    2010-01-01

    Review of Grass Roots: African Origins of an American Art. Dale Rosengarten, Theodore Rosengarten, and Enid Schildkrout, eds. 2008. Museum for African Art, New York. Distributed by University of Washington Press, Seattle. Pp. 269, copiously illustrated in black-and-white and color. ISBN (cloth) 978-0-945802-50-1, (paper) 978-0-945802-51-8.

  19. Weed-suppressive bacteria to reduce annual grass weeds

    Science.gov (United States)

    Cheatgrass (Bromus tectorum L.), medusahead (Taeniatherum caput-medusae [L.] Nevski) and jointed goatgrass (Aegilops cylindrica L.) are exotic, annual grasses that negatively affect cereal production in cropland; reduce protein-rich forage for cattle; choke out native plants in the shrub-steppe habi...

  20. Bringing Scientific Inquiry Alive Using Real Grass Shrimp Research

    Science.gov (United States)

    Aultman, Terry; Curran, Mary Carla; Partridge, Michael

    2010-01-01

    This lesson was developed for middle school students using actual research on grass shrimp ("Palaemonetes pugio") to illustrate the process of a scientific investigation. The research was conducted at Savannah State University and funded by the National Oceanic and Atmospheric Administration (NOAA) Office of Education through the Living Marine…

  1. Hygrothermal Properties and Performance of Sea Grass Insulation

    DEFF Research Database (Denmark)

    Eriksen, Marlene Stenberg Hagen; Laursen, Theresa Back; Rode, Carsten;

    2008-01-01

    In the attempt to obtain knowledge of the hygrothermal properties of sea grass as thermal insulation, experiments have been carried out in the laboratory to determine the thermal conductivity, sorption properties and the water vapour permeability of the material. In order to investigate...

  2. Nitrogen use efficiency in six perennial grasses from contrasting habitats.

    NARCIS (Netherlands)

    Vazquez de Aldana, B.R.; Berendse, F.

    1997-01-01

    1. We studied the nitrogen-use efficiency (NUE) in six perennial grasses adapted to a wide range of nutrient availability. The glasshouse experiment was carried out in pots containing nutrient solution, with two fertility treatments. Nitrogen-use efficiency was considered as the product of nitrogen

  3. Effect of machinery wheel load on grass yield

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian;

    2010-01-01

    Effect of machinery wheel load on grass   Ole Green1, Rasmus N. Jørgensen2, Kristian Kristensen3, René Gislum3, Dionysis Bochtis1, & Claus G. Sørensen1   1University of Aarhus, Dept. of Agricultural Engineering 2University of Southern Denmark, Inst. of Chemical Eng., Biotechnology and Environmental...

  4. C4 bioenergy crops for cool climates, with special emphasis on perennial C4 grasses.

    Science.gov (United States)

    Sage, Rowan F; de Melo Peixoto, Murilo; Friesen, Patrick; Deen, Bill

    2015-07-01

    There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates--Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)--all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to temperatures below -3 °C to -7 °C will kill overwintering rhizomes, while for upland switchgrass and cordgrass, rhizomes survive exposure to temperatures above -20 °C to -24 °C. Cordgrass emerges earlier than switchgrass and M. giganteus genotypes, but lacks the Miscanthus growth potential once warmer days of late spring arrive. To enable C4-based bioenergy production in colder climates, breeding priorities should emphasize improved cold tolerance of M.×giganteus, and enhanced productivity of switchgrass and cordgrass. This should be feasible in the near future, because wild populations of each species exhibit a diverse range of cold tolerance and growth capabilities.

  5. Structure of the natural transgene PgiC2 in the common grass Festuca ovina.

    Directory of Open Access Journals (Sweden)

    Pernilla Vallenback

    Full Text Available BACKGROUND: A horizontal gene transfer has brought an active nuclear gene, PgiC2, from a polyploid Poa species (P. palustris or a close relative into the common grass sheep's fescue (Festuca ovina. The donor and the receptor species are strictly reproductively separated, and PgiC2 occurs in a polymorphic state within F. ovina. The active gene copy is normally closely linked to a very similar pseudogene. METHODOLOGY/PRINCIPAL FINDINGS: By genome walking we have obtained the up- and downstream sequences of PgiC2 and of corresponding genes in the donor and recipient species. Comparisons of these sequences show that the complete upstream region necessary for the gene's expression is included in the transferred segment. About 1 kb upstream of PgiC2 a fragment with transposition associated properties has been found (TAF. It is present in P. palustris and its polyploid relatives, though not at the homologous position, and is absent from many other grasses, including non-transgenic F. ovina plants. It is possible that it is a part of a transposing element involved in getting the gene into a transferring agent and/or into the recipient chromosome. CONCLUSIONS/SIGNIFICANCE: The close similarity of the up- and downstream regions with the corresponding regions in P. palustris excludes all suggestions that PgiC2 is not a HGT but the result of a duplication within the F. ovina lineage. The small size of the genetic material transferred, the complex nature of the PgiC2 locus, and the associated fragment with transposition associated properties suggest that the horizontal transfer occurred via a vector and not via illegitimate pollination.

  6. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as...

  7. From the Lab Bench: Differences in annual and perennial grasses in meeting cattle production goals

    Science.gov (United States)

    A column was written that provided the advantages and disadvantages of annual warm- and cool-season grasses. Warm-season annual grasses can increase the supply of forage during the summer slump in cool-season perennial grass growth. Utilization of toxic endophyte-infected tall fescue pastures can ...

  8. Data on litter quality of host grass plants with and without fungal endophytes

    Directory of Open Access Journals (Sweden)

    P.E. Gundel

    2016-06-01

    Full Text Available Certain Pooideae species form persistent symbiosis with fungal endophytes of Epichloë genus. Although endophytes are known to impact the ecology and evolution of host species, their effects on parameters related with quality of plant biomass has been elusive. This article provides information about parameters related with the quality of plant litter biomass of two important grass species (Schedonorus phoenix and Schedonorus pratensis affected by the symbiosis with fungal endophytes (Epichloë coenophiala and Epichloë uncinata, respectively. Four population origins of S. phoenix and one of S. pratensis were included. Mineral, biochemical and structural parameters were obtained from three samples per factors combination [species (and population origin×endophyte]. This data can be potentially used in other studies which, by means of ‘data reanalyzing’ or meta-analysis, attempt to find generalizations about endophyte effects on host plant litter biomass. The present data is associated with the research article “Role of foliar fungal endophytes on litter decomposition among species and population origins” (Gundel et al., In preparation [1].

  9. Data on litter quality of host grass plants with and without fungal endophytes.

    Science.gov (United States)

    Gundel, P E; Helander, M; Garibaldi, L A; Vázquez-de-Aldana, B R; Zabalgogeazcoa, I; Saikkonen, K

    2016-06-01

    Certain Pooideae species form persistent symbiosis with fungal endophytes of Epichloë genus. Although endophytes are known to impact the ecology and evolution of host species, their effects on parameters related with quality of plant biomass has been elusive. This article provides information about parameters related with the quality of plant litter biomass of two important grass species (Schedonorus phoenix and Schedonorus pratensis) affected by the symbiosis with fungal endophytes (Epichloë coenophiala and Epichloë uncinata, respectively). Four population origins of S. phoenix and one of S. pratensis were included. Mineral, biochemical and structural parameters were obtained from three samples per factors combination [species (and population origin)×endophyte]. This data can be potentially used in other studies which, by means of 'data reanalyzing' or meta-analysis, attempt to find generalizations about endophyte effects on host plant litter biomass. The present data is associated with the research article "Role of foliar fungal endophytes on litter decomposition among species and population origins" (Gundel et al., In preparation) [1]. PMID:27182541

  10. Nitrogen inputs promote the spread of an invasive marsh grass.

    Science.gov (United States)

    Tyler, Anna Christina; Lambrinos, John G; Grosholz, Edwin D

    2007-10-01

    Excess nutrient loading and large-scale invasion by nonnatives are two of the most pervasive and damaging threats to the biotic and economic integrity of our estuaries. Individually, these are potent forces, but it is important to consider their interactive impacts as well. In this study we investigated the potential limitation of a nonnative intertidal grass, Spartina alterniflora, by nitrogen (N) in estuaries of the western United States. Nitrogen fertilization experiments were conducted in three mud-flat habitats invaded by S. alterniflora in Willapa Bay, Washington, USA, that differed in sediment N. We carried out parallel experiments in San Francisco Bay, California, USA, in three habitats invaded by hybrid Spartina (S. alterniflora x S. foliosa), in previously unvegetated mud flat, and in native S. foliosa or Salicornia virginica marshes. We found similar aboveground biomass and growth rates between habitats and estuaries, but end-of-season belowground biomass was nearly five times greater in San Francisco Bay than in Willapa Bay. In Willapa Bay, aboveground biomass was significantly correlated with sediment N content. Addition of N significantly increased aboveground biomass, stem density, and the rate of spread into uninvaded habitat (as new stems per day) in virtually all habitats in both estuaries. Belowground biomass increased in Willapa Bay only, suggesting that belowground biomass is not N limited in San Francisco Bay due to species differences, N availability, or a latitudinal difference in the response of Spartina to N additions. The relative impact of added N was greater in Willapa Bay, the estuary with lower N inputs from the watershed, than in San Francisco Bay, a highly eutrophic estuary. Nitrogen fertilization also altered the competitive interaction between hybrid Spartina and Salicornia virginica in San Francisco Bay by increasing the density and biomass of the invader and decreasing the density of the native. There was no significant effect

  11. Fungi colonising the above-ground parts of fodder galega (Galega orientalis Lam. cultivated in pure sowing and mixed with smooth brome-grass (Bromus inermis Leyss.

    Directory of Open Access Journals (Sweden)

    Bożena Cwalina-Ambroziak

    2012-12-01

    Full Text Available Field experiments were carried out in 1999-2001 in the experimental field in Knopin near Dobre Miasto to determine the intensity of fodder galega diseases cultivated in pure sowing and mixed with smooth brome-grass (the Hillstrand and Auld' s modified scale, 1982. The fungi colonising the phyllosphere of fodder galega were analysed in a laboratory (Chruoeciak , 1974. The following symptoms were observed in fodder galega: ascochyta blight (Ascochyta sp., gray mould (Botrytis cinerea and plant wilting (Fusarium oxysporum.. The climatic conditions had an effect on the development of diseases. The greatest intensity of gray mould (Ii = 24.3% and plant wilting (17.9% of plants with the disease symptoms were observed in 2001. Ascochyta blight occurred with the lowest intensity and the highest infection index in 1999 in the cultivation of fodder galega mixed with smooth brome-grass was only 12.1%. The type of cultivation also modified fodder galega disease intensity. Gray mould and plant wilting developed better in pure sowing than in mixed sowing with smooth brome-grass. Throughout the entire experiment period the average infection index was 22.8% and 15.9% of plants with the wilt symptoms. Ascochyta blight found better conditions for development in plants cultivated in a mix with smooth brome-grass (average infection index - 10.0%. The fodder galega phyllosphere provided 4149 fungal isolates represented by 17 species and yeast-like fungi. Yeast-like fungi dominated (75.6% of the total isolates. The following species were less numerous: Botrytis cinerea, Humicola brevis, Acremonium strictum and Cladosporium cladosporioides. From the leaves of fodder galega cultivated in pure sowing, 3.8% more fungi were obtained than from the leaves of plants cultivated with a mix of smooth brome-grass, including more frequently isolated pathogenic fungi representing the genera of Fusarium and the species of Botrytis cinerea.

  12. Characterization of grass carp spleen transcriptome during GCRV infection.

    Science.gov (United States)

    Xu, B H; Zhong, L; Liu, Q L; Xiao, T Y; Su, J M; Chen, K J; Wang, H Q; Dai, Y J; Chen, J

    2016-01-01

    The aim of the study was to investigate the grass carp hemorrhagic infection pathway and its key-related genes. Grass carp reovirus (GCRV) might cause hemorrhagic disease in grass carps. Healthy grass carp fingerlings (N = 60) were divided into control and infected groups. Fish in the control group were intraperitoneally (ip) injected with 0.6% fish physiological saline; the infected group received 5,000,000 50% tissue culture infective doses of GCRV 873 standard strain, a double-stranded RNA (dsRNA) virus strain, ip, in 0.5 mL. Illumina HiSeqTM 2000 was used for transcriptome sequencing, and real-time polymerase chain reaction (PCR) used to detect complement factors II (C2), III (C3), and V (C5); profibrinolysin (PLG); and coagulation factor II (F2) expression. A total of 2,722,223 reads were detected in the control group, and 2,751,111 in the infected group. Among 11,023 unigenes obtained after transcriptome assembly, 10,021 unigenes were significantly differentially expressed. Gene ontology and KEGG analysis, a collection of databases dealing with genomes and biological pathways, were performed to classify unigenes into functional categories, to understand gene function and identify regulatory pathways. Real-time PCR analysis showed that C2, C3, C5, PLG, and F2 expression levels were down-regulated, confirming results of pathway-enrichment analysis. This is the first application of high-throughput sequencing technology to investigate the in vivo effects of GCRV, on genes and pathways involved in the immune response to infection in grass carp. PMID:27173223

  13. Lead phytoremediation potential of Vetiver grass: a hydroponic study

    Science.gov (United States)

    Pachanoor, D. S.; Andra, S. P.; Datta, R.; Sarkar, D.

    2006-05-01

    Lead (Pb) is a toxic heavy metal that is released into the environment from a variety of sources. Sources of Pb contamination in soils can be divided into three broad categories: industrial activities, such as mining and smelting processes, agricultural activities, such as application of insecticide and municipal sewage sludge, and urban activities, such as use of Pb in gasoline, paints, and other materials. Severe Pb contamination of soils may cause a variety of environmental problems, including loss of vegetation, groundwater contamination and Pb toxicity in plants, animals and humans. The use of plants to remove toxic metals from soils (phytoremediation) is fast emerging as an acceptable strategy for cost-effective and environmentally sound remediation of contaminated soils. The objective of this study was to gain insight into the lead uptake potential and biochemical stress response mechanism in vetiver grass (Vetiveria zizanioides L.) upon exposure to Pb in contaminated soils. We investigated the effect of increasing concentrations of Pb on vetiver grass grown in a hydroponic system. Plant response to the addition of phosphate in the presence of Pb was also studied. Biochemical stress response was studied by monitoring the activities of Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes. The results indicated that exposure to Pb in the range of 0 ppm -1200 ppm had no significant negative effects on the growth of vetiver grass. There was no considerable decrease in vetiver biomass, implying the potential of this grass for Pb phytoremediation. The translocation of Pb from the root to the shoot was up to 20%. The SOD activity was in positive correlation with Pb concentrations in the solution, but no such trend was observed with GPx. In systems containing phosphate fertilizer, lead precipitated out immediately, thereby decreasing the soluble concentration of lead, resulting in less availability of Pb to the grass.

  14. Abscisic acid metabolite profiling as indicators of plastic responses to drought in grasses from arid Patagonian Monte (Argentina).

    Science.gov (United States)

    Cenzano, Ana M; Masciarelli, O; Luna, M Virginia

    2014-10-01

    The identification of hormonal and biochemical traits that play functional roles in the adaptation to drought is necessary for the conservation and planning of rangeland management. The aim of this study was to evaluate the effects of drought on i) the water content (WC) of different plant organs, ii) the endogenous level of abscisic acid (ABA) and metabolites (phaseic acid-PA, dihydrophaseic acid-DPA and abscisic acid conjugated with glucose ester-ABA-GE), iii) the total carotenoid concentration and iv) to compare the traits of two desert perennial grasses (Pappostipa speciosa and Poa ligularis) with contrasting morphological and functional drought resistance traits and life-history strategies. Both species were subjected to two levels of gravimetric soil moisture (the highest near field capacity during autumn-winter and the lowest corresponding to summer drought). Drought significantly increased the ABA and DPA levels in the green leaves of P. speciosa and P. ligularis. Drought decreased ABA in the roots of P. speciosa while it increased ABA in the roots of P. ligularis. P. ligularis had the highest ABA level and WC in green leaves. While P. speciosa had the highest DPA levels in leaves. In conclusion, we found the highest ABA level in the mesophytic species P. ligularis and the lowest ABA level in the xerophytic species P. speciosa, revealing that the ABA metabolite profile in each grass species is a plastic response to drought resistance. PMID:25245790

  15. Effect of mixing low palatable grasses of heteropogon contortus with ipil ipil leaves on digestibility in goats

    International Nuclear Information System (INIS)

    The study was conducted at the National Agricultural Research Centre, Islamabad, Pakistan during 2012 to find out the effect of mixing low palatable grasses of Heteropogon contortus (HC), with tree leaves of Leucaena leucocephala (Ipil ipil, II) in the ratio of 75:25, 50:50, 25:75, along with sole species on their digestibility in small ruminants. Goats fed II/sub 100%/, HC/sub 25%/ II/sub 75%/, HC/sub 50%/ II/sub 50%/, HC/sub 75%/ II/sub 25%/ and HC/sub 100%/ had similar dry matter (DM), crude protein (CP) and crude fibre (CF) consumption among all the treatments. The digestibility percentage of dry matter intake (DMI) varied among the treatments ranging from 68.25% to 41.66%. Mixtures of low palatable grass and Ipil ipil were in general more digestible with more than 65% dry matter digestibility. The lowest digestibility of dry matter (41.66%) was observed in HC/sub 100%/. A similar trend was noted for CP digestibility. However, reverse trend was observed in digestibility of CF where highest digestibility was recorded in HC100% and lowest in II100%. It can be concluded that grass and ipil ipil leaf mixture are better regarding forage quality and nutrient digestibility and can be recommended as animal feed. (author)

  16. The contribution of the pineal gland on daily rhythms and masking in diurnal grass rats, Arvicanthis niloticus.

    Science.gov (United States)

    Shuboni, Dorela D; Agha, Amna A; Groves, Thomas K H; Gall, Andrew J

    2016-07-01

    Melatonin is a hormone rhythmically secreted at night by the pineal gland in vertebrates. In diurnal mammals, melatonin is present during the inactive phase of the rest/activity cycle, and in primates it directly facilitates sleep and decreases body temperature. However, the role of the pineal gland for the promotion of sleep at night has not yet been studied in non-primate diurnal mammalian species. Here, the authors directly examined the hypothesis that the pineal gland contributes to diurnality in Nile grass rats by decreasing activity and increasing sleep at night, and that this could occur via effects on circadian mechanisms or masking, or both. Removing the pineal gland had no effect on the hourly distribution of activity across a 12:12 light-dark (LD) cycle or on the patterns of sleep-like behavior at night. Masking effects of light at night on activity were also not significantly different in pinealectomized and control grass rats, as 1h pulses of light stimulated increases in activity of sham and pinealectomized animals to a similar extent. In addition, the circadian regulation of activity was unaffected by the surgical condition of the animals. Our results suggest that the pineal gland does not contribute to diurnality in the grass rat, thus highlighting the complexity of temporal niche transitions. The current data raise interesting questions about how and why genetic and neural mechanisms linking melatonin to sleep regulatory systems might vary among mammals that reached a diurnal niche via parallel and independent pathways. PMID:27038859

  17. Assessment of Cytotoxic Activity of Three Plants of Pigweed, Bermuda grass and Burdock via Artemia Salina Test

    Directory of Open Access Journals (Sweden)

    parisa sadighara

    2010-01-01

    Full Text Available Introduction: Pigweed is a weed which grows in the pastures of Iran. Local people use the plant leaves to cook traditional food. Bermuda grass with its rapid growth and distribution is regarded a real threat to prairies and it can lead to tremors syndrome in cattle and sheep. Burdock which also grows in many parts of Iran is used as a medicinal herb. In this study, the cytotoxicity potential of the three plants was assessed via Artemia Salina test. Methods: Pigweed, Bermuda grass and burdock were collected from Ghaemshahr in the North of Iran. The leaves were dried and the essence of the three plants was extracted. The larvaes were hatched from cysts of Artemia salina at 26˚C in filtered seawater. The plant extracts with different concentration (10,100 and 1000ppm were added to the solution larvaes. Results: The LC50 values (the concentration which needed to die half the larvaes were measured for pigweed, Bermuda grass and burdock at 1640, 990, and 840 ppm, respectively. Conclusion: The results indicate that compared to the two other species, there is more priority for burdock to be studied in further studies for identification and assessment of toxicity

  18. DEVELOPMENT OF MOLECULAR MONITORING TECHNOLOGIES TO MEASURE TRANSGENE FLOW AND INTROGRESSION IN CROP AND NON-CROP PLANT SPECIES

    Science.gov (United States)

    The Gene Flow Project at the US Environmental Protection Agency, Western Ecology Division is developing methodologies for ecological risk assessments of transgene flow using Agrostis and Brassica engineered with CP4 EPSPS genes that confer resistance to glyphosate herbicide. In ...

  19. Analysis of phytochelatin complexes in the lead tolerant vetiver grass [Vetiveria zizanioides (L.)] using liquid chromatography and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Andra, Syam S., E-mail: syam.andra@gmail.co [Environmental Geochemistry Laboratory, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX (United States); Datta, Rupali [Biological Sciences, Michigan Technological University, Houghton, MI (United States); Sarkar, Dibyendu [Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ (United States); Saminathan, Sumathi K.M. [Environmental Geochemistry Laboratory, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX (United States); Mullens, Conor P.; Bach, Stephan B.H. [Department of Chemistry, University of Texas at San Antonio, San Antonio, TX (United States)

    2009-07-15

    Ethylenediamene tetraacetic acid (EDTA) has been used to mobilize soil lead (Pb) and enhance plant uptake for phytoremediation. Chelant bound Pb is considered less toxic compared to free Pb ions and hence might induce less stress on plants. Characterization of possible Pb complexes with phytochelatins (PC{sub n}, metal-binding peptides) and EDTA in plant tissues will enhance our understanding of Pb tolerance mechanisms. In a previous study, we showed that vetiver grass (Vetiveria zizanioides L.) can accumulate up to 19,800 and 3350 mg Pb kg{sup -1} dry weight in root and shoot tissues, respectively; in a hydroponics set-up. Following the basic incubation study, a greenhouse experiment was conducted to elucidate the efficiency of vetiver grass (with or without EDTA) in remediating Pb-contaminated soils from actual residential sites where Pb-based paints were used. The levels of total thiols, PC{sub n}, and catalase (an antioxidant enzyme) were measured in vetiver root and shoot following chelant-assisted phytostabilization. In the presence of 15 mM kg {sup -1} EDTA, vetiver accumulated 4460 and 480 mg Pb kg{sup -1} dry root and shoot tissue, respectively; that are 15- and 24-fold higher compared to those in untreated controls. Despite higher Pb concentrations in the plant tissues, the amount of total thiols and catalase activity in EDTA treated vetiver tissues was comparable to chelant unamended controls, indicating lowered Pb toxicity by chelation with EDTA. The identification of glutathione (referred as PC{sub 1}) (m/z 308.2), along with chelated complexes like Pb-EDTA (m/z 498.8) and PC{sub 1}-Pb-EDTA (m/z 805.3) in vetiver root tissue using electrospray tandem mass spectrometry (ES-MS) highlights the possible role of such species towards Pb tolerance in vetiver grass. - Chelated lead in conjunction with phytochelatins synthesis and complexation reduces stress in the lead tolerant vetiver grass.

  20. Evidence for adaptive evolution of low-temperature stress response genes in a Pooideae grass ancestor

    DEFF Research Database (Denmark)

    Vigeland, Magnus D; Spannagl, Manuel; Asp, Torben;

    2013-01-01

    Adaptation to temperate environments is common in the grass subfamily Pooideae, suggesting an ancestral origin of cold climate adaptation. Here, we investigated substitution rates of genes involved in low-temperature-induced (LTI) stress responses to test the hypothesis that adaptive molecular...... evolution of LTI pathway genes was important for Pooideae evolution. Substitution rates and signatures of positive selection were analyzed using 4330 gene trees including three warm climate-adapted species (maize (Zea mays), sorghum (Sorghum bicolor), and rice (Oryza sativa)) and five temperate Pooideae...... evidence for a link between adaptation to cold habitats and adaptive evolution of LTI stress responses in early Pooideae evolution and shed light on a poorly understood chapter in the evolutionary history of some of the world's most important temperate crops...

  1. Memory of the Vernalized State in Plants including the Model Grass Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Daniel P Woods

    2014-03-01

    Full Text Available Plant species that have a vernalization requirement exhibit variation in the ability to remember winter—i.e., variation in the stability of the vernalized state. Studies in Arabidopsis have demonstrated that molecular memory involves changes in the chromatin state and expression of the flowering repressor FLOWERING LOCUS C, and have revealed that single-gene differences can have large effects on the stability of the vernalized state. In the perennial Arabidopsis relative Arabis alpina, the lack of memory of winter is critical for its perennial life history. Our studies of flowering behavior in the model grass Brachypodium distachyon reveal extensive variation in the vernalization requirement, and studies of a particular Brachypodium accession that has a qualitative requirement for both cold exposure and inductive daylength reveals that Brachypodium can exhibit a highly stable vernalized state.

  2. Interrelationships among plant biomass, plant surface area and the interception of particulate deposition by grasses

    International Nuclear Information System (INIS)

    The interrelationships among plant biomass, plant surface area and interception fraction were determined for the interception by corn of 238Pu-bearing particles released to the atmosphere from the H-Area nuclear fuels chemical separations facility on the U.S. Department of Energy's Savannah River Plant in Barnwell County, South Carolina. The relationship between interception fraction and corn biomass was accurately approximated by a filtration model with an absorption coefficient of 3.60 m2 kg-1. A filtration model with an absorption coefficient of 2.91 m2 kg-1 accurately approximated the relationship between biomass and interception fraction for data compiled from the literature for a variety of grass species. A linear regression model accurately approximated the relationship between interception fraction and surface area, but was not a better predictor of interception fraction than the filtration model for biomass

  3. DNA transposon activity is associated with increased mutation rates in genes of rice and other grasses.

    Science.gov (United States)

    Wicker, Thomas; Yu, Yeisoo; Haberer, Georg; Mayer, Klaus F X; Marri, Pradeep Reddy; Rounsley, Steve; Chen, Mingsheng; Zuccolo, Andrea; Panaud, Olivier; Wing, Rod A; Roffler, Stefan

    2016-01-01

    DNA (class 2) transposons are mobile genetic elements which move within their 'host' genome through excising and re-inserting elsewhere. Although the rice genome contains tens of thousands of such elements, their actual role in evolution is still unclear. Analysing over 650 transposon polymorphisms in the rice species Oryza sativa and Oryza glaberrima, we find that DNA repair following transposon excisions is associated with an increased number of mutations in the sequences neighbouring the transposon. Indeed, the 3,000 bp flanking the excised transposons can contain over 10 times more mutations than the genome-wide average. Since DNA transposons preferably insert near genes, this is correlated with increases in mutation rates in coding sequences and regulatory regions. Most importantly, we find this phenomenon also in maize, wheat and barley. Thus, these findings suggest that DNA transposon activity is a major evolutionary force in grasses which provide the basis of most food consumed by humankind. PMID:27599761

  4. The Effect of Orobanche crenata Infection Severity in Faba Bean, Field Pea, and Grass Pea Productivity

    Science.gov (United States)

    Fernández-Aparicio, Mónica; Flores, Fernando; Rubiales, Diego

    2016-01-01

    Broomrape weeds (Orobanche and Phelipanche spp.) are root holoparasites that feed off a wide range of important crops. Among them, Orobanche crenata attacks legumes complicating their inclusion in cropping systems along the Mediterranean area and West Asia. The detrimental effect of broomrape parasitism in crop yield can reach up to 100% depending on infection severity and the broomrape-crop association. This work provides field data of the consequences of O. crenata infection severity in three legume crops, i.e., faba bean, field pea, and grass pea. Regression functions modeled productivity losses and revealed trends in dry matter allocation in relation to infection severity. The host species differentially limits parasitic sink strength indicating different levels of broomrape tolerance at equivalent infection severities. Reductions in host aboveground biomass were observed starting at low infection severity and half maximal inhibitory performance was predicted as 4.5, 8.2, and 1.5 parasites per faba bean, field pea, and grass pea plant, respectively. Reductions in host biomass occurred in both vegetative and reproductive organs, the latter resulting more affected. The increase of resources allocated within the parasite was concomitant to reduction of host seed yield indicating that parasite growth and host reproduction compete directly for resources within a host plant. However, the parasitic sink activity does not fully explain the total host biomass reduction because combined biomass of host–parasite complex was lower than the biomass of uninfected plants. In grass pea, the seed yield was negligible at severities higher than four parasites per plant. In contrast, faba bean and field pea sustained low but significant seed production at the highest infection severity. Data on seed yield and seed number indicated that the sensitivity of field pea to O. crenata limited the production of grain yield by reducing seed number but maintaining seed size. In contrast

  5. A comparison of canopy evapotranspiration between perennial rhizomatous grasses and Zea mays

    Science.gov (United States)

    Hickman, G.; Bernacchi, C.; Dohleman, F.

    2008-12-01

    Perennial rhizomatous C4 grasses are currently considered one of the most promising vegetation types to accommodate a cellulosic feedstock based liquid fuel economy. The current focus on using these vegetation types as a source of renewable fuel has sparked numerous concerns associated with environmental impacts. Of particular interest is the impact that altering the composition of vegetation at the landscape scale would have on local and regional hydrological cycles. We hypothesize that evapotranspiration, ET, will be higher for perennial grasses relative to maize as a result higher leaf area, higher above-ground biomass and prolonged growing seasons. To test this hypothesis, a technique in which ET is estimated as the residual in the energy balance equation from measurements of net radiation and sensible and latent heat fluxes was employed. Measurements were made during the 2007 growing season for three replicate plots of the perennial rhizomatous grasses Miscanthus giganteus and Panicum virgatum, as well as for Zea mays planted at the University of Illinois South Farms. When averaged across the entire growing season, ET for M. giganteus was double relative to Z. mays, and 130% of P. virgatum ET. When compared over the periods in which all three species experienced mature and closed canopies (from day of year 200 to 250), M. giganteus still showed higher rates of ET compared with Z. mays, however, the increase was only ~15%. We conclude that ET associated with perennial alternative energy crops are higher relative to annual row crop; with most ET disparity, particularly for P. virgatum, being driven by phenology, quicker canopy closure and a prolonged growing season. Physiological rates of ET were highest for M. giganteus, followed by Z. mays, followed P. virgatum. Differences in phenology were more important than those of physiology for ET overshadowing effects from increased biomass associated with M. giganteus and/or a physiological difference between these

  6. Grasses and legumes in mixture: an energy intercropping system intended for anaerobic digestion

    Directory of Open Access Journals (Sweden)

    Giuseppe Gatta

    2013-03-01

    Full Text Available Batch testing of biomethanization was conducted on organic matrices from a mixture of grasses (triticale and barley and legumes (field bean - Vicia faba L. var. minor. These tests were performed in mesophylic conditions (35°C on previously chopped and ensiled biomass. The three crops have been cultivated in Southern Italy (Puglia region, both as single-crops and intercropping between triticale or barley and field bean, in different mixture combinations, during the season 2009-2010. Emphasis was placed on the determination of the chemical composition of feedstock from the three single species and their different intercropping ratios, mowed at two subsequent stages (milk and dough development of grasses, also assessing their consequent biogas and methane potential yields after silage. Seven overall treatments have been compared: the three species in monoculture (triticale, barley and field bean, respectively; two mixtures between triticale and field bean (with triticale at 70 and 50%, respectively; two mixtures between barley and field bean (again with barley at 70 and 50%, respectively. Immediately after cutting and for the next 90 days, biomass samples were closed into plastic mini-silos, each having a 5-L capacity, in order to simulate the silage process. Thereafter, the batch testing was performed and biogas and methane production have been determined, with respect to the main chemical characteristics of the chopped and ensiled biomass samples, able to affect biogas and methane yield. Considering the single-crop treatments the highest biogas per hectare production has been found with respect to triticale (8737.1 nm3 ha-1 and barley (8837.6 nm3 ha-1, at the first and second harvesting stage, respectively. Concerning grass-legume intercropping, the highest biogas yield (8635.0 nm3 ha-1 was observed with reference to the 70:30 mixing ratio, specifically on barley mowed at the milk development stage. The methane content in the biogas ranged from

  7. Linking phenology and biomass productivity in South Dakota mixed-grass prairie

    Science.gov (United States)

    Rigge, Matthew; Smart, Alexander; Wylie, Bruce; Gilmanov, Tagir; Johnson, Patricia

    2013-01-01

    Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe plant community condition; the phenology of production can provide inferences on species composition, successional stage, and grazing impacts. We evaluate the productivity and phenology of western South Dakota mixed-grass prairie using 2000 to 2008 Moderate Resolution Imaging Spectrometer (MODIS) normalized difference vegetation index (NDVI) satellite imagery at 250 m spatial resolution. Growing season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool (C3) and warm (C4) season species. Additionally, a variety of phenological indicators including cool season percentage of TIN were derived from the seasonal profiles of NDVI. Cool season percentage and TIN were combined to generate vegetation classes, which served as proxies of plant community condition. TIN decreased with precipitation from east to west across the study area. Alternatively, cool season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of mid-summer precipitation. Cool season TIN averaged 76.8% of total. Seasonal accumulation of TIN corresponded closely (R2 > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to the TIN and cool season percentage products. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool/warm season composition, and vegetation classes can improve the efficiency of land management by adjusting stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and

  8. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  9. Dry matter yields and hydrological properties of three perennial grasses of a semi-arid environment in East Africa

    NARCIS (Netherlands)

    Mganga, K.Z.; Musimba, N.K.R.; Nyariki, D.M.; Nyangito, M.M.; Mwangombe, A.W.; Ekaya, W.N.; Clavel, D.; Francis, J.; Kaufmann, Von R.; Verhagen, J.; Muiri, W.M.

    2010-01-01

    Enteropogon macrostachyus (Bush rye), Cenchrus ciliaris L. (African foxtail grass) and Eragrostis superba Peyr (Maasai love grass) are important perennial rangeland grasses in Kenya. They provide an important source of forage for domestic livestock and wild ungulates. These grasses have been used ex

  10. Estimating the content of clover and grass in the sward using a consumer camera and image processing

    DEFF Research Database (Denmark)

    Mortensen, Anders Krogh; Karstoft, Henrik; Søegaard, Karen;

    the dry matter ratio of clover and grass in clover grass fields from sparse close up images. First, the light conditions is determined, which is used for selecting model parameters to estimate the coverage of both clover and grass. Next, the clover and grass coverage are transformed to give the dry matter...

  11. Lipid composition of grains from wild grasses

    Directory of Open Access Journals (Sweden)

    Zydgalo, J. A.

    1995-02-01

    Full Text Available Physicochemical characteristics, fatty acid and sterol composition were studied in grains of Agropyron elongatum, Bromus catharticus, Festuca arundinacea, Stipa hyaline and Panicum maximum. The highest protein level was found in A. elongatum. Linoleic and palmitic acids were the predominant fatty acids in all species, β-sitosterol was by far the most prominent sterol component in all samples, while Δ7-stigmasterol was detected in only trace amounts.

    Se estudió las características físico-químicas, la composición de ácidos grasos y esteroles de Agropyron elongatum, Bromus catharticus, Festuca arundinacea, Stipa hialina y Panicum maximum. Los niveles más altos de proteínas fueron encontrados en A. elongatum. Dentro de los ácidos grasos el linoleico y el palmítico fueron los predominantes. En todas las muestras el β-sitosterol fue el esterol que se presentó en mayor cantidad, mientras que el Δ7-estigmasterol fue detectado en cantidades trazas.

  12. Recovery of Trichostrongylus colubriformis infective larvae from three grass species contaminated in the autumn Recuperação de larvas infectantes de Trichostrongylus colubriformis em três espécies de gramíneas contaminadas no outono

    Directory of Open Access Journals (Sweden)

    Raquel Abdallah da Rocha

    2012-12-01

    Full Text Available This experiment aimed to assess the recovery of infective larvae (L3 of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm. TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM, recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.O experimento teve como objetivo avaliar a recuperação de larvas infectantes (L3 de Trichostrongylus colubriformis em Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross e Panicum maximum cv. Aruana. Foram utilizados módulos experimentais constituídos por seis canteiros, perfazendo dois canteiros por espécie forrageira. A sobrevivência larval foi avaliada do outono até o inverno, sob o efeito de duas alturas de poda (5 e 30 cm. A poda foi realizada imediatamente antes da deposição das fezes contaminadas com ovos de T. colubriformis. A colheita das fezes e da forragem foi realizada uma, duas, quatro, oito, 12 e 16 semanas após a deposição das fezes nos canteiros experimentais. De

  13. Enzymes from Fungal and Plant Origin Required for Chemical Diversification of Insecticidal Loline Alkaloids in Grass-Epichloë Symbiota

    OpenAIRE

    Juan Pan; Minakshi Bhardwaj; Padmaja Nagabhyru; Grossman, Robert B.; Schardl, Christopher L

    2014-01-01

    The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for...

  14. Sustainable bioethanol production combining biorefinery principles using combined raw materials from wheat undersown with clover-grass

    OpenAIRE

    Thomsen, Mette Hedegaard; Hauggaard-Nielsen, Henrik

    2008-01-01

    To obtain the best possible net energy balance of the bioethanol production the biomass raw materials used need to be produced with limited use of non-renewable fossil fuels. Intercropping strategies are known to maximize growth and productivity by including more than one species in the crop stand, very often with legumes as one of the components. In the present study clover-grass is undersown in a traditional wheat crop. Thereby, it is possible to increase input of symbiotic fixation of atmo...

  15. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    Science.gov (United States)

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. PMID:27367811

  16. In situ spectral reflectance studies of tidal wetland grasses

    Science.gov (United States)

    Bartlett, D. S.; Klemas, V.

    1981-01-01

    Field measurements of wetland spectral canopy reflectance in the Landsat-MSS wavebands were correlated with biotic factors. The highest single band correlations were observed between visible (MSS Band 4: 0.5 to 0.6 micron and Band 5: 0.6 to 0.7 micron) canopy reflectance and the percentage, by weight, of live (green) vegetation in the canopies of Spartina alterniflora (salt marsh cordgrass), Spartina patens (salt meadow grass), and Distichlis spicata (spike grass). Infrared canopy reflectance displayed significant but weaker dependence on canopy parameters such as live and total biomass and canopy height. The Band 7 (0.8 to 1.1 microns)/Band 5 (0.6 to 0.7 micron) reflectance ratio was found to be highly correlated with green biomass for S. alterniflora. Highest spectral separability between the 'low marsh' S. alterniflora and the 'high marsh' Salt Hay (S. patens and D. spicata) communities in Delaware occurs during December.

  17. Do urban canyons influence street level grass pollen concentrations?

    DEFF Research Database (Denmark)

    Peel, Robert George; Kennedy, Roy; Smith, Matt;

    2014-01-01

    to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local......In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre...... street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found...

  18. The determination of radionuclides in grass ecosystem samples

    International Nuclear Information System (INIS)

    The radioactive debris cloud from the Chernobyl reactor accident resulted in some deposition over essentially all of the Northern Hemisphere. Shortly after the accident invitations were sent out by the IAEA to Member States to collect grass samples according to specific instructions so that the ratio of the various radionuclides in the fallout debris could be established over a wide area of Europe. In response to this request, 20 grass samples were provided by Member States. To establish a protocol for analysis of these valuable samples and to recommend a protocol for future sample collection, a Consultants Meeting was called by the IAEA for 23-25 September 1986. This document contains the considerations and recommendations of the consultants

  19. Changes in seagrass species composition in northwestern Gulf of Mexico estuaries: effects on associated seagrass fauna.

    Directory of Open Access Journals (Sweden)

    Brandon R Ray

    Full Text Available The objective of this study was to measure the communities associated with different seagrass species to predict how shifts in seagrass species composition may affect associated fauna. In the northwestern Gulf of Mexico, coverage of the historically dominant shoal grass (Halodule wrightii is decreasing, while coverage of manatee grass (Syringodium filiforme and turtle grass (Thalassia testudinum is increasing. We conducted a survey of fishes, crabs, and shrimp in monospecific beds of shoal, manatee, and turtle grass habitats of South Texas, USA to assess how changes in sea grass species composition would affect associated fauna. We measured seagrass parameters including shoot density, above ground biomass, epiphyte type, and epiphyte abundance to investigate relationships between faunal abundance and these seagrass parameters. We observed significant differences in communities among three seagrass species, even though these organisms are highly motile and could easily travel among the different seagrasses. Results showed species specific relationships among several different characteristics of the seagrass community and individual species abundance. More work is needed to discern the drivers of the complex relationships between individual seagrass species and their associated fauna.

  20. Fatty Acids, α-Tocopherol, β-Carotene and Lutein Contents in Forage Legumes, Forbs and a Grass-Clover Mixture

    DEFF Research Database (Denmark)

    Elgersma, A.; Søegaard, Karen; Jensen, Søren Krogh

    2013-01-01

    Fresh forages are an important natural source of vitamins and fatty acids in ruminant diets, and their concentrations in forage species are important for the quality of animal-derived foods such as dairy and meat products. The aims of this study were to obtain novel information on vitamins...... and fatty acids (FA) in a variety of forage legumes and non-legume forb species compared to a grass-clover mixture and to explore implications for animal-derived products. Seven dicotyledons [four forbs (salad burnet ( Sanguisorba minor ), caraway ( Carum carvi ), chicory ( Cichorium intybus ), and ribwort...... (33.7-35.7 g 100 g(-1) FA) proportions of n-3 FA. This study demonstrated higher vitamin concentrations in some forbs compared with major forages such as lucerne and grass-clover, more total FA in salad burnet, caraway, and birdsfoot trefoil than in lucerne, and higher n-3 FA concentrations in all...

  1. Stable Isotope Mapping of Alaskan Grasses and Marijuana

    Science.gov (United States)

    Booth, A. L.; Wooller, M. J.

    2008-12-01

    The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing

  2. Grass plants bind, retain, uptake and transport infectious prions

    OpenAIRE

    Sandra Pritzkow; Rodrigo Morales; Fabio Moda; Uffaf Khan; Glenn C. Telling; Edward Hoover; Claudio Soto

    2015-01-01

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-...

  3. EFFECT OF AQUEOUS PRETREATMENT ON PYROLYSIS CHARACTERISTICS OF NAPIER GRASS

    OpenAIRE

    ISAH YAKUB MOHAMMED; YOUSIF ABDALLA ABAKR; FEROZ KABIR; SUZANA YUSUP

    2015-01-01

    Effect of non-catalytic aqueous pretretment on pyrolysis characteristics of Napier grass was investigated using thermogravimetric analyser. Increasing pretreatment severity (0.0-2.0) improved pyrolysis process. The residual mass at the end of pyrolysis for the pretreated sample was about 50% less compared to the untreated sample. Kinetics of the process was evaluated using order based model and both pretreated and untreated samples followed first order reaction. The activation energy of the p...

  4. Digestion and nitrogen metabolism of grass fed dairy cows.

    OpenAIRE

    Vuuren, van, W Wim

    1993-01-01

    Until recently, young, highly digestible grass was considered an ideal feed for dairy cows. However, research during the last decades has shown that the nutrient supply of grazing animals is insufficient for milk productions above c. 29 kg per day. Experiments in England and New Zealand have shown that the efficiency of protein utilization is relatively low and consequently, a high proportion of ingested nitrogen is excreted in urine and faeces. This reports the effects of grassland managemen...

  5. Terpenes in lamb fat to trace animal grass feeding

    Directory of Open Access Journals (Sweden)

    A. Priolo

    2011-03-01

    Full Text Available Several efforts have been done in the last years to trace grass feeding directly in the herbivore products and different methods, based on carotenoid pigments (Priolo et al., 2002; Prache et al., 2003 have been proposed. Some volatile compounds, such as 2,3-octanedione or 3-methylindole (skatole have been indicated as excellent indicators of pasture diets (Young et al., 1997...

  6. Phytoextraction of lead from firing range soil by Vetiver grass.

    Science.gov (United States)

    Wilde, E W; Brigmon, R L; Dunn, D L; Heitkamp, M A; Dagnan, D C

    2005-12-01

    Phytoextraction techniques utilizing a sterile strain of Vetiver grass (Vetiveria zizanoides) along with soil amendments were evaluated for removing lead and other elements such as Zn, Cu, and Fe from the soil of a 50-year old active firing range at the Savannah River Site (SRS). Lead-contaminated soil (300-4500 ppm/kg) was collected, dried, placed in pots, fertilized, and used as a medium for growing transplanted Vetiver grass plants in a greenhouse. The uptake of metals by the plants was evaluated in response to various fertilization and pre-harvest treatment schemes. Baseline metal concentrations in the soil of all pots were measured prior to planting and when the plants were harvested. Plants grew better when fertilized with Osmocote fertilizer in comparison to plants fertilized with 10-10-10 (NPK) fertilizer. Application of a chelating agent, EDTA, one week prior to harvest significantly increased the amount of lead that was phytoextracted. Lead concentrations of up to 1390-1450 ppm/kg in tissue samples were detected. Maximum Pb levels were observed in root tissues. The addition of non-lethal doses of a slow-release herbicide in combination with EDTA did not appear to further enhance phytoextraction or the translocation of Pb into shoots. The study indicated that the use of Vetiver grass coupled with the use of chelating soil amendments has considerable potential for use as a remedial strategy for lead-contaminated soils such as those associated with firing ranges. PMID:15964059

  7. Phytoremediation potential of vetiver grass [Chrysopogon zizanioides (L.)] for tetracycline.

    Science.gov (United States)

    Datta, Rupali; Das, Padmini; Smith, Stephanie; Punamiya, Pravin; Ramanathan, Dil M; Reddy, Ramana; Sarkar, Dibyendu

    2013-01-01

    The presence of veterinary and human antibiotics in soil and surface water is an emerging environmental concern. The current study was aimed at evaluating the potential of using vetiver grass as a phytoremediation agent in removing Tetracycline (TC) from aqueous media. The study determined uptake, translocation, and transformation of TC in vetiver grass as function of initial antibiotic concentrations and exposure time. Vetiver plants were grown for 60 days in a greenhouse in TC contaminated hydroponic system. Preliminary results show that complete removal of tetracycline occurred within 40 days in all TC treatments. Initial concentrations of TC had significant effect (p < 0.0001) on the kinetics of removaL Tetracycline was detected in the root as well as shoot tissues, confirming uptake and root-to-shoot translocation. Liquid-chromatography-tandem-mass-spectrometry analysis of plant tissue samples suggest presence of metabolites of TC in both root and shoot tissues of vetiver grass. The current data is encouraging and is expected to aid in developing a cost-effective, in-situ phytoremediation technique to remove TC group of antibiotics from wastewater. PMID:23488000

  8. Additives in ensiling palisade grass managed under grazing intensities

    Directory of Open Access Journals (Sweden)

    Felipe Barros Macedo

    2015-10-01

    Full Text Available Conservation of summer forage excess represents a management strategy to meet animals' needs for dry matter in the shortage period, but has been poorly studied. Silage can be used for this purpose. This study analyzed the production of palisade grass silage from pasture subjected to different grazing intensities with and without additive, determining losses by gases and effluents and chemical composition of silage. The experiment was a 4 x 3 factorial completely randomized design, with four replications. The factors were: 1st – herbage allowance of 5% (5 kg dry matter 100 kg-1 of animal weight day-1, 10, 15 and 20%. The pasture was managed under rotational stocking with 35-day grazing cycles (7 days of occupation and 28 days of rest and 2nd - additives: a control; b citrus pulp pellets; c biological inoculant for grass silage. The forage of palisade grass harvested from pastures subjected to low-intensity grazing showed quantitative and qualitative characteristics for ensiling. However, high humidity and low fermentable carbohydrate require the use of additive, favor the fermentation process and increase the nutritional quality of silage.

  9. Development of a sublingual allergy vaccine for grass pollinosis

    Directory of Open Access Journals (Sweden)

    Franco Frati

    2010-06-01

    Full Text Available Franco Frati1,2, Silvia Scurati1, Paola Puccinelli1, Marie David3, Cecile Hilaire4, Maurizio Capecce4, Francesco Marcucci2, Cristoforo Incorvaia51Medical and Scientific Department, Stallergenes, Milan, Italy; 2University Department of Medical and Surgical Specialties and Public Health, Perugia, Italy; 3Laboratoire Stallergenes, Antony, France; 4Marketing Department, Stallergenes, Milan, Italy; 5Allergy/Pulmonary Rehabilitation Unit, ICP Hospital, Milan, ItalyAbstract: Grass pollen is a very common cause of allergic rhinitis and asthma. The only treatment targeting the underlying causes of allergy is immunotherapy (IT. Sublingual immunotherapy (SLIT has been introduced to solve the problem of systemic reactions to subcutaneous IT (SCIT. This article evaluates the characteristics of the allergen extract, Staloral, in terms of practical administration, effectiveness, safety, and mechanism of action. Efficacy data were obtained from double-blind, placebo-controlled studies using Staloral in patients sensitized to grass pollen, while practical administration, cost-effectiveness, and mechanism of action data were provided by well designed studies. The efficacy and safety of Staloral, as demonstrated by review of published studies which used doses up to 1125 times those administered with SCIT, shows that this allergen extract has optimal characteristics for treating patients with seasonal allergies due to grass pollens. The main mechanism of action is the interaction between dendritic cells of the oral mucosa and the subsequent tolerance induced in T-cells.Keywords: allergen extracts, high-dose, efficacy, safety, sublingual immunotherapy

  10. Tolerable Time-Varying Overflow on Grass-Covered Slopes

    Directory of Open Access Journals (Sweden)

    Steven A. Hughes

    2015-03-01

    Full Text Available Engineers require estimates of tolerable overtopping limits for grass-covered levees, dikes, and embankments that might experience steady overflow. Realistic tolerance estimates can be used for both resilient design and risk assessment. A simple framework is developed for estimating tolerable overtopping on grass-covered slopes caused by slowly-varying (in time overtopping discharge (e.g., events like storm surges or river flood waves. The framework adapts the well-known Hewlett curves of tolerable limiting velocity as a function of overflow duration. It has been hypothesized that the form of the Hewlett curves suggests that the grass erosion process is governed by the flow work on the slope above a critical threshold velocity (referred to as excess work, and the tolerable erosional limit is reached when the cumulative excess work exceeds a given value determined from the time-dependent Hewlett curves. The cumulative excess work is expressed in terms of overflow discharge above a critical discharge that slowly varies in time, similar to a discharge hydrograph. The methodology is easily applied using forecast storm surge hydrographs at specific locations where wave action is minimal. For preliminary planning purposes, when storm surge hydrographs are unavailable, hypothetical equations for the water level and overflow discharge hydrographs are proposed in terms of the values at maximum overflow and the total duration of overflow. An example application is given to illustrate use of the methodology.

  11. Detection of grass carp reovirus (GCRV) with monoclonal antibodies.

    Science.gov (United States)

    Hongli, Jing; Lifeng, Zhang; Zhenzhen, Fang; Lipu, Xu; Min, Zhang; Na, Wang; Yulin, Jiang; Xiangmei, Lin

    2014-04-01

    Grass carp reovirus (GCRV) is a pathogen that causes hemorrhagic disease of grass carp. It is the most serious infectious disease of carp and causes serious losses of fingerlings of grass carp and black carp. In this study, a recombinant VP4, one of the viral core proteins, was constructed with a histidine tag and expressed at a high level in E. coli, and the expressed protein was mainly found in the form of inclusion bodies. The expressed VP4 protein was recognized by an anti-His-tag monoclonal antibody and goat anti-GCRV serum. Four monoclonal antibodies (16B7, 39E12, 13C3 and 14D1) against the recombinant VP4 protein were produced. These MAbs did not react with any of the tested viruses or fish cells lines in the ELISA tests except GCRV. In western blotting analysis, a protein band was observed when the recombinant VP4 protein of GCRV was used as an antigen, but a 68-kDa band was observed when natural capsid proteins of GCRV were used as antigens. Furthermore, a sandwich ELISA was developed for detection of GCRV. The detection limit of the test was 105 TCID50 of GCRV per mL. PMID:24122108

  12. Green grasses as light harvesters in dye sensitized solar cells

    Science.gov (United States)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-01

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  13. Pygrass: An Object Oriented Python Application Programming Interface (API) for Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS)

    OpenAIRE

    Marco Ciolli; Sören Gebbert; Pietro Zambelli

    2013-01-01

    PyGRASS is an object-oriented Python Application Programming Interface (API) for Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS), a powerful open source GIS widely used in academia, commercial settings and governmental agencies. We present the architecture of the PyGRASS library, covering interfaces to GRASS modules, vector and raster data, with a focus on the new capabilities that it provides to GRASS users and developers. Our design concept of the mo...

  14. An Integrated Multi-Omics Approach Reveals the Effects of Supplementing Grass or Grass Hay with Vitamin E on the Rumen Microbiome and Its Function.

    Science.gov (United States)

    Belanche, Alejandro; Kingston-Smith, Alison H; Newbold, Charles J

    2016-01-01

    in feed degradability (+8%), possibly as a result of its antioxidant properties which led to higher bacterial and protozoal levels. Vitamin E supplementation also modified the levels of some methanogen species indicating that they may be particularly sensitive to oxidative stresses. Our findings suggested that when possible, grass should be fed instead of grass hay, in order to improve rumen function and to decrease the environmental impact of livestock agriculture. PMID:27375609

  15. An Integrated Multi-Omics Approach Reveals the Effects of Supplementing Grass or Grass Hay with Vitamin E on the Rumen Microbiome and Its Function

    Science.gov (United States)

    Belanche, Alejandro; Kingston-Smith, Alison H.; Newbold, Charles J.

    2016-01-01

    in feed degradability (+8%), possibly as a result of its antioxidant properties which led to higher bacterial and protozoal levels. Vitamin E supplementation also modified the levels of some methanogen species indicating that they may be particularly sensitive to oxidative stresses. Our findings suggested that when possible, grass should be fed instead of grass hay, in order to improve rumen function and to decrease the environmental impact of livestock agriculture. PMID:27375609

  16. Facilitation or competition? Tree effects on grass biomass across a precipitation gradient.

    Directory of Open Access Journals (Sweden)

    Aristides Moustakas

    Full Text Available Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm, with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm, grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients.

  17. Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses.

    Science.gov (United States)

    Cardoso, Juan Andrés; Pineda, Marcela; Jiménez, Juan de la Cruz; Vergara, Manuel Fernando; Rao, Idupulapati M

    2015-01-01

    Drought severely limits forage productivity of C4 grasses across the tropics. The avoidance of water deficit by increasing the capacity for water uptake or by controlling water loss are common responses in forage C4 grasses. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C4 grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to overcome water-limited conditions. Therefore, assessments of cumulative transpired water, shoot growth, leaf rolling, leaf gas exchange, dry mass production and a number of morpho-physiological traits were recorded over a period of 21 days under well-watered or drought conditions. Drought reduced shoot dry mass of both grasses by 35 %, yet each grass exhibited contrasting strategies to cope with water shortage. Napier grass transpired most available water by the end of the drought treatment, whereas a significant amount of water was still available for Mulato II. Napier grass maintained carbon assimilation until the soil was fairly dry, whereas Mulato II restricted water loss by early stomatal closure at relatively wet soil conditions. Our results suggest that Napier grass exhibits a 'water-spending' behaviour that might be targeted to areas with intermittent drought stress, whereas Mulato II displays a 'water-saving' nature that could be directed to areas with longer dry periods. PMID:26333827

  18. Predicting potential global distributions of two Miscanthus grasses: implications for horticulture, biofuel production, and biological invasions.

    Directory of Open Access Journals (Sweden)

    Heather A Hager

    Full Text Available In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk.

  19. Differential freezing resistance and photoprotection in C3 and C4 eudicots and grasses.

    Science.gov (United States)

    Liu, Mei-Zhen; Osborne, Colin P

    2013-05-01

    Globally, C4 plants dominate hot, open environments, but this general pattern is underpinned by important differences in the biogeography of C4 lineages. In particular, the species richness of C4 Poaceae (grasses) increases strongly with increasing temperature, whereas that of the major C4 eudicot group Chenopodiaceae correlates positively with aridity. Freezing tolerance is a crucial determinant of biogeographical relationships with temperature and is mediated by photodamage and cellular disruption by desiccation, but little is known about differences between C4 families. This study hypothesized that there is a greater risk of freezing damage via these mechanisms in C4 Poaceae than Chenopodiaceae, that freezing protection differs between the taxonomic groups, and that freezing tolerance of species is linked to arid habitat preference. Chlorophyll fluorescence, water relations, and freezing injury were compared in four C3 and six C4 species of Poaceae and Chenopodiaceae from the same Mongolian flora. Contrary to expectations, freezing-induced leaf mortality and photodamage were lower in Poaceae than Chenopodiaceae species, and unrelated to photosynthetic pathway. The freezing resistance of Poaceae species resulted from constitutive protection and cold acclimation and an ability to protect the photosynthetic apparatus from photodamage. Freezing protection was associated with low osmotic potential and low tissue elasticity, and freezing damage was accompanied by electrolyte leakage, consistent with cell-membrane disruption by ice. Both Chenopodiaceae and Poaceae had the potential to develop cold acclimation and withstand freezing during the growing season, which conflicted with the hypothesis. Instead, freezing tolerance was more closely associated with life history and ecological preference in these Mongolian species. PMID:23599273

  20. Allelopathic Potential of Invasive Plantago virginica on Four Lawn Species.

    Science.gov (United States)

    Wang, Huatian; Zhou, Yumei; Chen, Yang; Wang, Quanxi; Jiang, Lifen; Luo, Yiqi

    2015-01-01

    Plantago virginica L. has invaded many lawn ecosystems in the Eastern part of China. The invasion has incurred an economic cost to remove them. In order to prevent the invasion, it is critical to understand the invasive mechanisms of this species. However, few studies have been conducted on the allelopathic mechanisms of its invasion. In this study, we examined allelopathic effects of P. virginica on germination of seeds and growth of seedlings of four widely used lawn species. We found extensive allelopathic potential of P. virginica on other lawn species, which varied with species and developmental stage. While most effects of the extracts of P. virginica were inhibitory, some variables in some species were promoted by the addition of the extracts. The extracts of P. virginica significantly inhibited seed germination of Agrostis matsumurae. While the overall differences in seed germination rate of Poa annua were significant among treatments, difference between control and any of the treatments was not significant. The height of seedlings of A. matsumurae and Cynodon dactylon was significantly lower under the treatments of adding extracts of P. virginica. In contrast, growth of seedlings of Festuca elata and P. annua did not show significant differences among treatments. The root length of A. matsumurae, C. dactylon and P. annua was suppressed by the extracts of P. virginica whereas root length of F. elata was not affected. Aboveground biomass of A. matsumurae and F. elata was significantly higher than control, except for F. elata at the concentration of 50mg/mL, whereas aboveground biomass of C. dactylon and P. annua was reduced at higher concentrations of the extracts. Except for A. matsumurae, root biomass of the other three lawn species declined under the treatments with the extracts of P. virginica. Our results revealed that P. virginica had allelopathic potential on four lawn species and supported the theory of "novel weapons hypothesis". Invasion by P

  1. Study advance on primary productivity of sea-grass%海草生产力研究进展

    Institute of Scientific and Technical Information of China (English)

    李森; 范航清; 邱广龙; 石雅君; 周如琼

    2011-01-01

    海草是生活在热带和温带海域浅水中的单子叶植物,具有较高的生产力,在全球的C、N、P循环中发挥着重要作用.作者对国内外海草生产力的研究进展和研究方法进行了综述,并分析了海草生产力的影响因素.海草地上部分生产力主要采用改进的Zieman标记法(如针孔法),地下部分采用末端标记法.影响海草生产力的因素包括海草种类、光照、无机碳源、温度、盐度、污染物及底质类型等.最后,作者指出了海草生产力研究存在的问题.%The sea-grass is the monocotyledon and lives in the neritic region of the tropical and temperate zones. The sea-grasses have high primary production, and play an important role in the cycle of carbon, nitrogen and phosphorus in the global scale. In this paper, the research advances and methods on the sea-grass'primary productivity at home and abroad reviewed. The influence factors of the sea-grass'primary productivity are discussed. The Modified Zieman's methods, for example, hole-punch method ,is the main method for above-ground primary productivity of the sea-grass, and marking rhizome terminals method is for under-ground. The variations of the seagrass primary productivity are determined by the various factors such as different seagrass species, irradiance level, inorgarnic carbon supply, water temperature, salinity, pollutants, sediment and so on. The deficiencies of the seagrass primary productivity study are also prospected.

  2. The effect of plant species on soil nitrogen mineralization

    NARCIS (Netherlands)

    Krift, van der A.J.; Berendse, F.

    2001-01-01

    1. To ascertain the influence of different plant species on nitrogen (N) cycling, we performed a long-term garden experiment with six grasses and five dicots with different potential growth rates, that are adapted to habitats with different nutrient supplies. We measured in situ N mineralization and

  3. Construction and Characterization of Grass Carp(Ctenopharyngodon idellus)Fosmid Library

    Institute of Scientific and Technical Information of China (English)

    JIA Zhen-hu; LIN Chang-you; YANG Tian-yao; JIANG Yi-nan; XIA Chun

    2010-01-01

    Grass carp(Ctenopharyngodon idellus)genomic fosmid library cotaining 129014 clones was constructed and characterized from one diploid grass carp.The average insert size of the fosmid library was determined to be 35 kb by pulsed field gel electrophoresis,which is 4.1-fold coverage of the grass carp genome.To demonstrate the probability of picking the functional genes from the library,eleven functional genes were screened by three-dimensional PCR technique.The number of positive clones of these genes was from 1 to 6.So,this library may screen any useful genes from grass carp.This grass carp genome fosmid library will be integrated in the presently ongoing efforts to determine the sequence of the grass carp genome.

  4. Senescing grass crops as regional sources of reactive volatile organic compounds

    Science.gov (United States)

    Karl, T.; Harren, F.; Warneke, C.; de Gouw, J.; Grayless, C.; Fall, R.

    2005-08-01

    Grass crop species, rice and sorghum, that are widely grown in the southeastern Texas region were analyzed for release of biogenic volatile organic compounds (VOCs) in simulated leaf-drying/senescence experiments. VOC release was measured by both online proton transfer reaction mass spectrometry (PTR-MS) and proton transfer ion trap mass spectrometry (PIT-MS) methods, and it was demonstrated that these two grass crops release a large variety of oxygenated VOCs upon drying under laboratory conditions primarily from leaves and not from stems. VOC release from paddy rice varieties was much greater than from sorghum, and major VOCs identified by gas chromatography PTR-MS included methanol, acetaldehyde, acetone, n-pentanal, methyl propanal, hexenol, hexanal, cis-3-hexenal, and trans-2-hexenal. The latter four VOCs, all C6 compounds known to be formed in wounded leaves, were the major volatiles released from drying rice leaves; smaller but substantial amounts of acetaldehyde were observed in all drying experiments. Online detection of VOCs using PIT-MS gave results comparable to those obtained with PTR-MS, and use of PIT-MS with collision-induced dissociation of trapped ions allowed unambiguous determination of the ratios of cis- and trans-hexenals during different phases of drying. As rice is one of the largest harvested crops on a global scale, it is conceivable that during rice senescence releases of biogenic VOCs, especially the reactive C6 wound VOCs, may contribute to an imbalance in regional atmospheric oxidant formation during peak summer/fall ozone formation periods. A county-by-county estimate of the integrated emissions of reactive biogenic VOCs from sorghum and rice production in Texas suggests that these releases are orders of magnitude lower than anthropogenic VOCs in urban areas but also that VOC emissions from rice in southeastern coastal Texas may need to be included in regional air quality assessments during periods of extensive harvesting.

  5. The use of reed canary grass and giant miscanthus in the phytoremediation of municipal sewage sludge.

    Science.gov (United States)

    Antonkiewicz, Jacek; Kołodziej, Barbara; Bielińska, Elżbieta Jolanta

    2016-05-01

    The application of municipal sewage sludge on energy crops is an alternative form of recycling nutrients, food materials, and organic matter from waste. Municipal sewage sludge constitutes a potential source of heavy metals in soil, which can be partially removed by the cultivation of energy crops. The aim of the research was to assess the effect of municipal sewage sludge on the uptake of heavy metals by monocotyledonous energy crops. Sewage sludge was applied at doses of 0, 10, 20, 40, and 60 Mg DM · ha(-1) once, before the sowing of plants. In a 6-year field experiment, the effect of four levels of fertilisation with sewage sludge on the uptake of heavy metals by two species of energy crops, reed canary grass (Phalaris arundinacea L.) of 'Bamse' cultivar and giant miscanthus (Miscanthus × giganteus GREEF et DEU), was analysed. It was established that the increasing doses of sewage sludge had a considerable effect on the increase in biomass yield from the tested plants. Due to the increasing doses of sewage sludge, a significant increase in heavy metals content in the energy crops was recorded. The heavy metal uptake with the miscanthus yield was the highest at a dose of 20 Mg DM · ha(-1), and at a dose of 40 Mg DM · ha(-1) in the case of reed canary grass. Research results indicate that on account of higher yields, higher bioaccumulation, and higher heavy metal uptake, miscanthus can be selected for the remediation of sewage sludge. PMID:26841773

  6. Usability value and heavy metals accumulation in forage grasses grown on power station ash deposit

    OpenAIRE

    Simić Aleksandar S.; Dželetović Željko S.; Vučković Savo M.; Sokolović Dejan R.; Delić Dušica I.; Mandić Violeta T.; Anđelković Bojan S.

    2015-01-01

    The study of five forage grasses (Lolium multiflorum, Festuca rubra, Festuca arundinacea, Arrhenatherum elatius and Dactylis glomerata) was conducted on an uncontaminated cultivated land, of leached chernozem type, and on “Nikola Tesla A” (TENT A) thermal power station ash deposit. The concentrations of: As, Pb, Cd, Zn, Ni, Fe i Cu in grasses grown on two media were compared. Grass samples have been collected in tillering stage, when they were in full devel...

  7. Preference for C4 shade grasses increases hatchling performance in the butterfly, Bicyclus safitza.

    Science.gov (United States)

    Nokelainen, Ossi; Ripley, Brad S; van Bergen, Erik; Osborne, Colin P; Brakefield, Paul M

    2016-08-01

    The Miocene radiation of C4 grasses under high-temperature and low ambient CO 2 levels occurred alongside the transformation of a largely forested landscape into savanna. This inevitably changed the host plant regime of herbivores, and the simultaneous diversification of many consumer lineages, including Bicyclus butterflies in Africa, suggests that the radiations of grasses and grazers may be evolutionary linked. We examined mechanisms for this plant-herbivore interaction with the grass-feeding Bicyclus safitza in South Africa. In a controlled environment, we tested oviposition preference and hatchling performance on local grasses with C3 or C4 photosynthetic pathways that grow either in open or shaded habitats. We predicted preference for C3 plants due to a hypothesized lower processing cost and higher palatability to herbivores. In contrast, we found that females preferred C4 shade grasses rather than either C4 grasses from open habitats or C3 grasses. The oviposition preference broadly followed hatchling performance, although hatchling survival was equally good on C4 or C3 shade grasses. This finding was explained by leaf toughness; shade grasses were softer than grasses from open habitats. Field monitoring revealed a preference of adults for shaded habitats, and stable isotope analysis of field-sampled individuals confirmed their preference for C4 grasses as host plants. Our findings suggest that plant-herbivore interactions can influence the direction of selection in a grass-feeding butterfly. Based on this work, we postulate future research to test whether these interactions more generally contribute to radiations in herbivorous insects via expansions into new, unexploited ecological niches. PMID:27551380

  8. Morphogenetic characteristics in Tanzania grass conhsorted with Stylosanthes Campo Grande or fertilized with nitrogen under grazing

    OpenAIRE

    Túlio Otávio Jardim D'Almeida Lins; Ulysses Cecato; Alyson Andrade Pinheiro; Bruno Shigueo Iwamoto; Alexandre Krutzmann; Tatiane Beloni; Robério Rodrigues Silva

    2015-01-01

    This study aimed to study morphogenic and structural characteristics of Tanzania grass (Panicum maximum cv. Tanzania) intercropped with Estilosantes Campo Grande (Stylosanthes capitata and Stylosanthes macrocephala) or fertilized with nitrogen. The pasture was managed under continuous stocking and variable stocking rate. Were used a randomized complete blocks with split plots and three replications. The treatments were: Tanzania grass + Stylosanthes; Tanzania grass + 75 Kg N.ha. year-1; Tanza...

  9. Use of wastewater and compost extracts as nutrient sources for growing nursery and turfgrass species.

    Science.gov (United States)

    Michitsch, Robert C; Chong, Calvin; Holbein, Bruce E; Voroney, R Paul; Liu, Hua-Wu

    2007-01-01

    Nutrient salts present in liquid by-products following waste treatment are lost resources if not effectively recycled, and can cause environmental problems if improperly disposed. This research compared the growth response and mineral nutrient status of two nursery and two turfgrass species, hydroponically supplied with nutritive by-product extracts derived from anaerobically digested municipal solid waste (MSW) and aerobically composted organic wastes from the mushroom and MSW industries. Forsythia (Forsythia x intermedia 'Lynwood') and weigela (Weigela florida 'Red Prince'), and creeping bentgrass (Agrostis palustris Huds.) and Kentucky bluegrass (Poa pratensis L.), were grown in nutrient solutions/extracts prepared from: (i) half-strength Hoagland's #2 solution (HH; control), (ii) Plant Products liquid fertilizer (PP; g kg(-1): 180 N; 39 P; 224 K), (iii) spent mushroom compost (SMC), (iv) MSW compost (GMC), and (v) intra-process wastewater from the anaerobic digestion of MSW (ADW). Additional nutrient solutions (SMC-A, GMC-A, and ADW-A) were prepared by amending the original solutions with N, P, and/or K to concentrations in HH (mg L(-1): 105 N; 15 P; 118 K). Plants receiving the SMC-A extract grew best or at least as well as those in HH, PP, and the amended GMC-A and ADW-A solutions. This study indicated that, with proper amendments of N, P, K and other nutrients, water-soluble constituents derived from organic waste treatment have potential for use as supplemental nutrient sources for plant production. PMID:17526882

  10. C3-C4 intermediacy in grasses: organelle enrichment and distribution, glycine decarboxylase expression, and the rise of C2 photosynthesis.

    Science.gov (United States)

    Khoshravesh, Roxana; Stinson, Corey R; Stata, Matt; Busch, Florian A; Sage, Rowan F; Ludwig, Martha; Sage, Tammy L

    2016-05-01

    Photorespiratory glycine shuttling and decarboxylation in bundle sheath (BS) cells exhibited by C2 species is proposed to be the evolutionary bridge to C4 photosynthesis in eudicots. To evaluate this in grasses, we compare anatomy, cellular localization of glycine decarboxylase (GDC), and photosynthetic physiology of a suspected C2 grass, Homolepis aturensis, with these traits in known C2 grasses, Neurachne minor and Steinchisma hians, and C3 S laxum that is sister to S hians We also use publicly available genome and RNA-sequencing data to examine the evolution of GDC subunits and enhance our understanding of the evolution of BS-specific GDC expression in C2 and C4 grasses. Our results confirm the identity of H aturensis as a C2 species; GDC is confined predominantly to the organelle-enriched BS cells in H aturensis and S hians and to mestome sheath cells of N minor Phylogenetic analyses and data obtained from immunodetection of the P-subunit of GDC are consistent with the hypothesis that the BS dominant levels of GDC in C2 and C4 species are due to changes in expression of a single GLDP gene in M and BS cells. All BS mitochondria and peroxisomes and most chloroplasts in H aturensis and S hians are situated centripetally in a pattern identical to C2 eudicots. In S laxum, which has C3-like gas exchange patterns, mitochondria and peroxisomes are positioned centripetally as they are in S hians This subcellular phenotype, also present in eudicots, is posited to initiate a facilitation cascade leading to C2 and C4 photosynthesis.

  11. Cervus elaphus Foraging Impacts on Plants and Soils at an Ungrazed Desert Grass/Shrubland in Northwestern New Mexico, USA

    Directory of Open Access Journals (Sweden)

    Louis C. Bender

    2015-01-01

    Full Text Available We evaluated Cervus elaphus herbivory and trampling impacts on plants and soils on Chaco Culture National Historical Park (Chaco, a desert grass/shrubland in northwestern New Mexico, USA, most (63% of which has been protected from grazing by domestic livestock since 1948. We conducted grazing, browse, and water infiltration surveys in areas which received different amounts of C. elaphus use (use and control, 2004–2007. Browse utilization was <32% on monitored species and Odocoileus hemionus use accounted for the majority of browsing. Live plant cover was greater on areas receiving more C. elaphus use, and no grass species were used above recommended levels. Stubble heights of Bouteloua spp. were positively related to relative C. elaphus use on some areas, suggesting possible stimulation of grassland productivity by C. elaphus grazing. Water infiltration rates either did not differ among use or control sites or were faster in use sites, indicating no impacts of C. elaphus use on soil compaction. At current C. elaphus densities (0.2–0.4/km2, negative impacts to plants and soils were not seen on Chaco, and some evidence suggests that light grazing is optimizing desert grasslands of Chaco.

  12. Genomics-Based Exploration of Virulence Determinants and Host-Specific Adaptations of Pseudomonas syringae Strains Isolated from Grasses

    Directory of Open Access Journals (Sweden)

    Alexey Dudnik

    2014-01-01

    Full Text Available The Pseudomonas syringae species complex has recently been named the number one plant pathogen, due to its economic and environmental impacts, as well as for its role in scientific research. The bacterium has been repeatedly reported to cause outbreaks on bean, cucumber, stone fruit, kiwi and olive tree, as well as on other crop and non-crop plants. It also serves as a model organism for research on the Type III secretion system (T3SS and plant-pathogen interactions. While most of the current work on this pathogen is either carried out on one of three model strains found on dicot plants with completely sequenced genomes or on isolates obtained from recent outbreaks, not much is known about strains isolated from grasses (Poaceae. Here, we use comparative genomics in order to identify putative virulence-associated genes and other Poaceae-specific adaptations in several newly available genome sequences of strains isolated from grass species. All strains possess only a small number of known Type III effectors, therefore pointing to the importance of non-Type III secreted virulence factors. The implications of this finding are discussed.

  13. Ecosystem Change in California Grasslands: Impacts of Species Invasion

    Science.gov (United States)

    Koteen, L. E.; Harte, J.; Baldocchi, D. D.

    2009-12-01

    Grassland ecosystems of California have undergone dramatic changes, resulting in the almost complete replacement of native perennial grasses by non-native annuals across millions of hectares of grassland habitat. Our research investigates the effects of this community shift on carbon, water and energy cycles at two sites in northern coastal California. Our goal was to understand how changes to California’s grasslands have affected climate through 1. shifting the balance of carbon storage between terrestrial stocks and the atmosphere, and 2. altering the water and energy regimes that heat or cool the earth's surface. To compare the processes that govern material exchange before and after annual grass invasion, we made use of sites where native vegetation is found adjacent to locations that have undergone non-native invasion. In plots of each vegetation type, we monitored whole plant productivity, root and litter decay rates and soil respiration, as well as soil climatic controls on these processes. At one site, we also measured surface albedo and the components of the surface energy balance in each grass community, using the surface renewal method. Although seemingly subtle, the shift in California grassland communities from native perennial to non-native annual grass dominance has had profound consequences for ecosystem biogeochemical, radiative and hydrological cycles. Soil carbon storage was found to be significantly greater in native perennial grass communities. Across both study sites, we found that non-native grass invasion has resulted in the transfer of from 3 to 6 tons of carbon per hectare from the soil to the atmosphere, dependent on site and species. A soil density fractionation and a radiocarbon analysis also revealed the carbon to be more recalcitrant in native grass dominated locations. The primary plant traits that help explain why soil carbon losses follow annual grass invasion are: 1. differences between annual and perennial grasses in above

  14. Reduction in clover-grass yield caused by different traffic intensities

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian;

    Different traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16...... different traffic intensities with 35 replicates and 1 traffic free treatment with 245 replicates, totalling 17 treatments randomized in a framework of 840 net parcels. The aim of this paper is to present the initial results concerning the impact on clover-grass yield caused by traffic intensities...

  15. Impact on Clover-Grass Yield from Wheel Load and Tyre Pressure

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Sørensen, Claus Aage Grøn

    2009-01-01

    Traffic intensities have been shown to have a negative influence on the yield of grass and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffic...... intensities with 35 replicates and 1 traffic free treatment with 245 replicates, totaling 17 treatments randomized in a framework of 840 net parcels. Significant results show that the wheel load affects the grass yield negatively and more than the tire pressure...

  16. Structural, productive and bromatologic characteristcs of Tifton 85 and Jiggs grasses fertilized with some macronutrients

    Directory of Open Access Journals (Sweden)

    Adauton Vilela de Rezende

    2015-06-01

    Full Text Available The aim this study was to evaluate the effect of fertilization of Tifton 85 and Jiggs grasses with some macronutrients on the structural, productive and bromatologic characteristics. Were evaluated two grasses (Cynodon dactylon cv. Tifton 85 and C. dactylon cv. Jiggs and five sources of fertilizer (three formulations NPK: 08-28-16, 30-00-20 and 20-10-10, and two sources nitrogen: urea and super N in a factorial scheme 2 x 5, distributed in a completely randomized design with four replications. The planting of grasses without fertilization was performed to simulate a pasture located in low natural fertility. The highest yields (P = 0.009 and ratios of leaves (P < 0.001 were observed in Tifton 85 grass, resulting in a lower proportion of stems when compared to Jiggs grass. The sources of fertilizers used changed the weight and the proportion of leaves and stems, as well as the leaf/stem ratio, number of tillers and mass production of Tifton 85 and Jiggs grasses. There was a significative interaction between the study factors (grass and fertilizer for concentrations of DM (P = 0.024, ADF (P = 0.012, hemicellulose (P = 0.007, DMD (P = 0.012, TDN (P = 0.012, DE (p = 0.012 and ME (P = 0.012 leaves and the protein content (p = 0.016 of the stem. In general, the application of 30-00-20 fertilizer resulted in lower ADF content in the leaves of Tifton 85 grass and higher DM, with higher energy content also, and providing super N implied lower ADF content and higher DM digestibility of Jiggs grass leaves. In the whole plant, the Jiggs grass had higher NDF (P = 0.017 compared to Tifton 85 grass, however, the concentration of ADF that grass was lower (P < 0.001 than Tifton 85 grass, which resulted in higher DM (P < 0.001 and energy intake (P < 0.001. The application of super N decreased the ADF content (P = 0.026 of grasses, mainly from Jiggs, implying an increase in the digestibility of DM (P = 0.026 and energy content (P = 0.026. Although there are

  17. Deriving Hydrological Response Units (HRUs) using a Web Processing Service implementation based on GRASS GIS

    OpenAIRE

    Christian Schwartze

    2009-01-01

    QGIS releases equal to or newer than 0.7 can easily connected to GRASS GIS by means of a toolbox that provides a wide range of standard GRASS modules you can launch – albeit only on data coming from GRASS. This QGIS plugin is expandable through XML configurations describing the assignment of options and inputs for a certain module. But how about embedding a precise workflow where the several processes don’t consist of a single GRASS module by force? Especially for a sequence of dependent task...

  18. Effect of Mercury Deposition on Mercury Content and Distribution in Rye Grass

    Institute of Scientific and Technical Information of China (English)

    WEISHIQIANG; J.SOMMAR; 等

    1997-01-01

    A grass(Italian rye grass)experiment with complete desing of three factos(Hg,grass and exposure)and two levels(with and withou the factor tested)was carried out in Goeteborg,Sweden from May to September,1995,toward understanding the effect of mercury deposition on plant Hg content and its distribution.It has been found that besides the two general pathways of Hg absorption,i.e.root uptake and foliar absorption,mercury deposition can aslo signifcantly incease Hg content and total load in grass.Such effects seem to be confined only within the above-ground parts of grass plant.Estimate has been made to make clear of the contributions of different pathways to Hg Content and total Hg load in the upper part of grass.Results showed that the contribution of Hg deposition accounted for 27%-32%,of Hg content in the above-ground parts of grass plant without adding Hg to the soil.decreasing with the increase of soil and/or air Hg concentrations.The increment of Hg load in the upper part of grass plant caused by Hg deposition during an interval of two weeks varied between 0.01-0.07μg pt-1,contributing to 17%-48% of the total Hg load in grass plant exposed.

  19. Identifying urban sources as cause of elevated grass pollen concentrations using GIS and remote sensing

    DEFF Research Database (Denmark)

    Skjøth, Carsten Ambelas; Ørby, Pia Viuf; Becker, Thomas;

    2013-01-01

    We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres of this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three...... available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations...

  20. Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM).

    Science.gov (United States)

    Yu, Kailiang; Foster, Adrianna

    2016-04-01

    Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

  1. Daily intake of lactating crossbred cows grazing elephant grass rotationally

    OpenAIRE

    Aroeira Luiz Januário Magalhães; Lopes Fernando César Ferraz; Soares João Paulo Guimarães; Deresz Fermino; Verneque Rui da Silva; Arcuri Pedro Braga; Matos Leovegildo Lopes de

    2001-01-01

    The goal of this trial was to estimate the total dry matter (TDMI) and daily pasture dry matter intakes (PDMI) by lactating crossbred Holstein - Zebu cows grazing elephant grass (Pennisetum purpureum Schum.) paddocks submitted to different rest periods. Three groups of 24 cows were used during two years. The paddocks were grazed during three days at the stocking rate of 4.5 cows/ha. Treatments consisted of resting periods of 30 days without concentrate and resting periods of 30, 37.5 and 45 d...

  2. Torrefaction of pellets from reed canary grass and softwood

    Energy Technology Data Exchange (ETDEWEB)

    Oerberg, Haakan [Swedish Univ. of Agricultural Science, Unit for Biomass Technology and Chemistry, Umeaa (Sweden); Pommer, Linda; Nordwaeger, Martin; Olofsson, Ingemar [Umeaa Univ., Dept. of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry, Umeaa (Sweden)

    2012-11-01

    In this work an energy crop, Reed Canary Grass (RCG) has been studied in comparison with Norway Spruce (NS ) when treated in a torrefaction process. In the torrefaction process biomass is heated in an inert atmosphere (250-340 deg C) and physical and chemical characteristics are then enhanced and the product becomes more similar to coal. Co-firing of torrefied biomass with coal in existing CHP plants, and gasification of torrefied biomass has recently been demonstrated in industrial scale with positive results.

  3. Men are grass: Bateson, Erickson, utilization and metaphor.

    Science.gov (United States)

    Roffman, Andrew E

    2008-01-01

    The relationship between metaphor and the practice of utilization in therapy and hypnosis can be seen as dependent on metaphor's role in structuring experience. The work of Gregory Bateson and others is used to illustrate how metaphor functions. Bateson's comparison of two forms of syllogistic logic provides a background for distinguishing between the experiential effects of metaphor in contrast to the categorical thinking inherent in simile and analogy. Clinical examples are given to demonstrate how utilization is structured by metaphor, particularly as Bateson has described it in his analysis of the Syllogism in Grass.

  4. 水分胁迫对混播草坪生理生态特性的影响%Influence of Water Stress on Physical Ecology Characteristics of Mixed Lawn Grass

    Institute of Scientific and Technical Information of China (English)

    李楠; 李海梅

    2014-01-01

    The resistance to water stress of three kinds of lawns were studied by pot experiment and field experiment.The T1 lawn as control contained single species Poa pretensis,the T2 lawn consisted of P.pretensis, Festuca arundinacea and Lolium perenne with the mixed ratio of 6∶2∶2,and the T3 lawn consisted of P.pretensis, F.rubra and Agrostis tenuis with the mixed ratio of 5∶4∶1 .The results were as following:along with the enhance-ment of water stress,the appearance quality comprehensive evaluation was in the order of T1 >T2 >T3 .T1 had the lowest decline of soil water content,leaf relative water content and root activity,followed by T2 ,and then T3 .The chlorophyll content in leaves followed the order of T1 >T2 >T3 .The resistance of these lawns to water stress were T1 >T2 >T3 .These lawns had different optimum soil water content,which the percentage of soil water content to field water capacity was 84.5%-94.8% for T1 ,80.4%-91 .8% for T2,and 77.5%-90.7% for T3.%为了研究混播草坪抗水分胁迫能力,采用盆栽试验与大田试验相结合的方法,以草地早熟禾(Poa pretensis)单播草坪(简称T1)为对照,以草地早熟禾、高羊茅(Festuca arundinacea)、多年生黑麦草(Loli-um perenne)混播草坪(简称T2,混播比例为6∶2∶2)和草地早熟禾、紫羊茅(F.rubra)、细弱翦股颖(Agrostis tenuis)混播草坪(简称T3,混播比例为5∶4∶1)为研究对象,分析水分胁迫对混播草坪生理生态特性的影响。结果表明,随着水分胁迫增加,3种草坪的外观质量综合评价表现为T1>T2>T3;单播草坪土壤含水量、叶片相对含水量及根系活力下降幅度均低于混播草坪,变幅表现为T3>T2>T1;而叶片叶绿素含量均值表现为T1>T2>T3。3种供试草坪抗水分胁迫能力表现为T1>T2>T3,T1适宜的土壤含水量占田间持水量百分比范围为84.5%~94.8%,T2为80.4%~91.8%,T3为77

  5. Evaluating nurse plants for restoring native woody species to degraded subtropical woodlands.

    Science.gov (United States)

    Yelenik, Stephanie G; DiManno, Nicole; D'Antonio, Carla M

    2015-01-01

    Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability. PMID:25709807

  6. Evolutionary implications of C3 -C4 intermediates in the grass Alloteropsis semialata.

    Science.gov (United States)

    Lundgren, Marjorie R; Christin, Pascal-Antoine; Escobar, Emmanuel Gonzalez; Ripley, Brad S; Besnard, Guillaume; Long, Christine M; Hattersley, Paul W; Ellis, Roger P; Leegood, Richard C; Osborne, Colin P

    2016-09-01

    C4 photosynthesis is a complex trait resulting from a series of anatomical and biochemical modifications to the ancestral C3 pathway. It is thought to evolve in a stepwise manner, creating intermediates with different combinations of C4 -like components. Determining the adaptive value of these components is key to understanding how C4 photosynthesis can gradually assemble through natural selection. Here, we decompose the photosynthetic phenotypes of numerous individuals of the grass Alloteropsis semialata, the only species known to include both C3 and C4 genotypes. Analyses of δ(13) C, physiology and leaf anatomy demonstrate for the first time the existence of physiological C3 -C4 intermediate individuals in the species. Based on previous phylogenetic analyses, the C3 -C4 individuals are not hybrids between the C3 and C4 genotypes analysed, but instead belong to a distinct genetic lineage, and might have given rise to C4 descendants. C3 A. semialata, present in colder climates, likely represents a reversal from a C3 -C4 intermediate state, indicating that, unlike C4 photosynthesis, evolution of the C3 -C4 phenotype is not irreversible. PMID:26524631

  7. Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses.

    Science.gov (United States)

    McKeown, Meghan; Schubert, Marian; Marcussen, Thomas; Fjellheim, Siri; Preston, Jill C

    2016-09-01

    The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones. Grasses of subfamily Pooideae, including several important crops, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and oats (Avena sativa), predominate in the northern temperate zone, and it is hypothesized that their radiation was facilitated by the early evolution of vernalization responsiveness. Predictions of this early origin hypothesis are that a response to vernalization is widespread within the subfamily and that the genetic basis of this trait is conserved. To test these predictions, we determined and reconstructed vernalization responsiveness across Pooideae and compared expression of wheat vernalization gene orthologs VERNALIZATION1 (VRN1) and VRN3 in phylogenetically representative taxa under cold and control conditions. Our results demonstrate that vernalization responsive Pooideae species are widespread, suggesting that this trait evolved early in the lineage and that at least part of the vernalization gene network is conserved throughout the subfamily. These results are consistent with the hypothesis that the evolution of vernalization responsiveness was important for the initial transition of Pooideae out of the tropics and into the temperate zone.

  8. Sexual size dimorphism and female reproduction in the white-striped grass lizard Takydromus wolteri

    Institute of Scientific and Technical Information of China (English)

    Laigao LUO; Yilian WU; Zhuyuan ZHANG; Xuefeng XU

    2012-01-01

    Sexual size dimorphism (SSD) has long attracted the attention of biologists,and life-history variation is thought to play an important role in the evolution of SSD.Here we quantified SSD and female reproductive traits to identify potential associations between SSD and female reproduction in the white-striped grass lizard Takydromus wolteri.In a population from Chuzhou,China,the largest male and female were 53.0 mm and 57.5 mm in snout-vent length (SVL),respectively.Females were larger in SVL and abdomen length,whereas males were larger in head size and tail length.Females produced up to five clutches of eggs during the breeding season,with large females producing more clutches and more eggs per clutch than small ones.As a result,large females had a higher annual fecundity and reproductive output.Egg size was positively correlated with maternal SVL in the first clutch,but not in subsequent clutches.These results suggest that T.wolteri is a species with female-biased SSD,and that fecundity selection,in which large females have higher fecundity due to their higher capacity for laying eggs,is likely correlated with the evolution of SSD in this species [Current Zoology 58 (2):236-243,2012].

  9. Testing assumptions of the enemy release hypothesis: generalist versus specialist enemies of the grass Brachypodium sylvaticum.

    Science.gov (United States)

    Halbritter, Aud H; Carroll, George C; Güsewell, Sabine; Roy, Bitty A

    2012-01-01

    The enemy release hypothesis (ERH) suggests greater success of species in an invaded range due to release from natural enemies. The ERH assumes there will be more specialist enemies in the native range and that generalists will have an equal effect in both ranges. We tested these assumptions with the grass Brachypodium sylvaticum in the native range (Switzerland) and invaded range (Oregon, USA). We assessed all the kinds of damage present (caused by fungi, insects, mollusk and deer) on both leaves and seeds at 10 sites in each range and correlated damage with host fitness. Only two of the 20 fungi found on leaves were specialist pathogens, and these were more frequent in the native range. Conversely there was more insect herbivory on leaves in the invaded range. All fungi and insects found on seeds were generalists. More species of fungi were found on seeds in the native range, and a higher proportion of them were pathogenic than in the invaded range. There were more kinds of enemies in the native range, where the plants had lower fitness, in accordance with the ERH. However, contrary to assumptions of the ERH, generalists appear to be equally or more important than specialists in reducing host fitness.

  10. Population regulation by enemies of the grass Brachypodium sylvaticum: demography in native and invaded ranges.

    Science.gov (United States)

    Roy, Bitty A; Coulson, Tim; Blaser, Wilma; Policha, Tobias; Stewart, Julie L; Blaisdell, G Kai; Güsewell, Sabine

    2011-03-01

    The enemy-release hypothesis (ERH) states that species become more successful in their introduced range than in their native range because they leave behind natural enemies in their native range and are thus "released" from enemy pressures in their introduced range. The ERH is popularly cited to explain the invasive properties of many species and is the underpinning of biological control. We tested the prediction that plant populations are more strongly regulated by natural enemies (herbivores and pathogens) in their native range than in their introduced range with enemy-removal experiments using pesticides. These experiments were replicated at multiple sites in both the native and invaded ranges of the grass Brachypodium sylvaticum. In support of the ERH, enemies consistently regulated populations in the native range. There were more tillers and more seeds produced in treated vs. untreated plots in the native range, and few seedlings survived in the native range. Contrary to the ERH, total measured leaf damage was similar in both ranges, though the enemies that caused it differed. There was more damage by generalist mollusks and pathogens in the native range, and more damage by generalist insect herbivores in the invaded range. Demographic analysis showed that population growth rates were lower in the native range than in the invaded range, and that sexually produced seedlings constituted a smaller fraction of the total in the native range. Our removal experiment showed that enemies regulate plant populations in their native range and suggest that generalist enemies, not just specialists, are important for population regulation.

  11. Females make tough neighbors: sex-specific competitive effects in seedlings of a dioecious grass.

    Science.gov (United States)

    Eppley, Sarah M

    2006-01-01

    If males and females of a species differ in their effect on intraspecific competition then this can have significant ecological and evolutionary consequences because it can lead to size and mortality disparities between the sexes, and thus cause biased population sex ratios. If the degree of sexual dimorphism of competitive effect varies across environments then this variation can generate sex ratio variation within and between populations. In a California population of Distichlis spicata, a dioecious grass species exhibiting extreme within-population sex ratio variation (spatial segregation of the sexes), I evaluated the intraspecific competitive effects of male and female D. spicata seedlings in three soil types. The sex of seedlings was determined using a RAPD-PCR marker co-segregating with female phenotype. Distichlis spicata seedlings, regardless of sex, were six times larger when grown with male versus female conspecific seedlings in soil from microsites where the majority of D. spicata plants are female, and this sexual dimorphism of competitive effect was weaker or did not occur in other soil types. This study suggests that it is not just the higher costs of female versus male reproduction itself that cause spatial segregation of the sexes in D. spicata, but that differences in competitive abilities between the sexes--which occur as early as the seedling stage--can generate sex ratio variation.

  12. Water Supply Changes N and P Conservation in a Perennial Grass Leymus chinensis

    Institute of Scientific and Technical Information of China (English)

    Ju-Ying Huang; Hai-Long Yu; Ling-Hao Li; Zhi-You Yuan; Samuel Bartels

    2009-01-01

    Changes in precipitation can influence soil water and nutrient availability, and thus affect plant nutrient conservation strategies. Better understanding of how nutrient conservation changes with variations in water availability is crucial for predicting the potential influence of global climate change on plant nutrient-use strategy. Here, green-leaf nitrogen (N) and phosphorus (P) concentrations, N- and P-resorption proficiency (the terminal N and P concentration in senescent leaves,NRP and PRP, respectively), and N- and P-resorption efficiency (the proportional N and P withdrawn from senescent leaves prior to abscission, NRE and PRE, respectively) of Leymus chinensis (Trin.) Tzvel., a typical perennial grass species in northern China, were examined along a water supply gradient to explore how plant nutrient conservation responds to water change. Increasing water supply at low levels ( 9000 mL/year). These results indicated that changes in water availability at low levels could affect leaf-level nutrient characteristics, especially for the species in semiarid ecosystems. Therefore, global changes in precipitation may pose effects on plant nutrient economy, and thus on nutrient cycling in the plant-soil systems.

  13. The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution.

    Science.gov (United States)

    Estep, M C; DeBarry, J D; Bennetzen, J L

    2013-02-01

    Sample sequence analysis was employed to investigate the repetitive DNAs that were most responsible for the evolved variation in genome content across seven panicoid grasses with >5-fold variation in genome size and different histories of polyploidy. In all cases, the most abundant repeats were LTR retrotransposons, but the particular families that had become dominant were found to be different in the Pennisetum, Saccharum, Sorghum and Zea lineages. One element family, Huck, has been very active in all of the studied species over the last few million years. This suggests the transmittal of an active or quiescent autonomous set of Huck elements to this lineage at the founding of the panicoids. Similarly, independent recent activity of Ji and Opie elements in Zea and of Leviathan elements in Sorghum and Saccharum species suggests that members of these families with exceptional activation potential were present in the genome(s) of the founders of these lineages. In a detailed analysis of the Zea lineage, the combined action of several families of LTR retrotransposons were observed to have approximately doubled the genome size of Zea luxurians relative to Zea mays and Zea diploperennis in just the last few million years. One of the LTR retrotransposon amplification bursts in Zea may have been initiated by polyploidy, but the great majority of transposable element activations are not. Instead, the results suggest random activation of a few or many LTR retrotransposons families in particular lineages over evolutionary time, with some families especially prone to future activation and hyper-amplification.

  14. Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses1[OPEN

    Science.gov (United States)

    McKeown, Meghan; Fjellheim, Siri

    2016-01-01

    The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones. Grasses of subfamily Pooideae, including several important crops, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and oats (Avena sativa), predominate in the northern temperate zone, and it is hypothesized that their radiation was facilitated by the early evolution of vernalization responsiveness. Predictions of this early origin hypothesis are that a response to vernalization is widespread within the subfamily and that the genetic basis of this trait is conserved. To test these predictions, we determined and reconstructed vernalization responsiveness across Pooideae and compared expression of wheat vernalization gene orthologs VERNALIZATION1 (VRN1) and VRN3 in phylogenetically representative taxa under cold and control conditions. Our results demonstrate that vernalization responsive Pooideae species are widespread, suggesting that this trait evolved early in the lineage and that at least part of the vernalization gene network is conserved throughout the subfamily. These results are consistent with the hypothesis that the evolution of vernalization responsiveness was important for the initial transition of Pooideae out of the tropics and into the temperate zone. PMID:27474116

  15. Dietary pantothenic acid deficiency and excess depress the growth, intestinal mucosal immune and physical functions by regulating NF-κB, TOR, Nrf2 and MLCK signaling pathways in grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Li, Li; Feng, Lin; Jiang, Wei-Dan; Jiang, Jun; Wu, Pei; Kuang, Sheng-Yao; Tang, Ling; Tang, Wu-Neng; Zhang, Yong-An; Zhou, Xiao-Qiu; Liu, Yang

    2015-08-01

    This study investigated the effects of dietary pantothenic acid (PA) on the growth, intestinal mucosal immune and physical barrier, and relative mRNA levels of signaling molecules in the intestine of grass carp (Ctenopharyngodon idella). A total of 540 grass carp (253.44 ± 0.69 g) were fed six diets with graded levels of PA (PA1, PA15, PA30, PA45, PA60 and PA75 diets) for 8 weeks. The results indicated that compared with PA deficiency (PA1 diet) and excess (PA75 diet) groups, optimal PA supplementation increased (P TOR) mRNA expression levels in some intestinal segments; (2) reactive oxygen species, malondialdehyde and protein carbonyl contents, and Kelch-like ECH-associating protein 1a, Kelch-like ECH-associating protein 1b in the intestine; (3) Claudin 12, Claudin 15a and myosin light-chain kinase (MLCK) mRNA levels in some intestinal segments of grass carp. In conclusion, optimum PA promoted growth, intestinal mucosal immune and physical function, as well as regulated mRNA levels of signaling molecules NF-κB P65, TOR, Nrf2 and MLCK in grass carp intestine. Based on the quadratic regression analysis of PWG and intestinal lysozyme activity, the optimal PA levels in grass carp (253.44-745.25 g) were estimated to be 37.73 mg/kg and 41.38 mg/kg diet, respectively.

  16. Testing framework for GRASS GIS: ensuring reproducibility of scientific geospatial computing

    Science.gov (United States)

    Petras, V.; Gebbert, S.

    2014-12-01

    GRASS GIS, a free and open source GIS, is used by many scientists directly or through other projects such as R or QGIS to perform geoprocessing tasks. Thus, a large number of scientific geospatial computations depend on quality and correct functionality of GRASS GIS. Automatic functionality testing is therefore necessary to ensure software reliability. Here we present a testing framework for GRASS GIS which addresses different needs of GRASS GIS and geospatial software in general. It allows to test GRASS tools (referred to as GRASS modules) and examine outputs including large raster and vector maps as well as temporal datasets. Furthermore, it enables to test all levels of GRASS GIS architecture including C and Python application programming interface and GRASS modules invoked as subprocesses. Since GRASS GIS is used as a platform for development of geospatial algorithms and models, the testing framework allows not only to test GRASS GIS core functionality but also tools developed by scientists as a part of their research. Using testing framework we can test GRASS GIS and related tools automatically and repetitively and thus detect errors caused by code changes and new developments. Tools and code are then easier to maintain which results in preserving reproducibility of scientific results over time. Similarly to open source code, the test results are publicly accessible, so that all current and potential users can see them. The usage of testing framework will be presented on an example of a test suite for r.slope.aspect module, a tool for computation of terrain slope, aspect, curvatures and other terrain characteristics.

  17. Long-term ecological consequences of herbicide treatment to control the invasive grass, Spartina anglica, in an Australian saltmarsh

    Science.gov (United States)

    Shimeta, Jeff; Saint, Lynnette; Verspaandonk, Emily R.; Nugegoda, Dayanthi; Howe, Steffan

    2016-07-01

    Invasive plants acting as habitat modifiers in coastal wetlands can have extensive ecological impacts. Control of invasive plants often relies on herbicides, although little is known about subsequent environmental impacts. Studying effects of herbicides on non-target species and long-term cascading consequences may yield insights into the ecology of invasive species by revealing interactions with native species. We conducted a long-term field experiment measuring effects of treating the invasive saltmarsh grass, Spartina anglica, with the herbicide Fusilade Forte®. No changes in sedimentary macrofaunal abundances or species richness, diversity, or assemblages were detected 1-2 months after spraying, despite known toxicity of Fusilade Forte® to fauna. This lack of impact may have been due to low exposure, since the herbicide was taken up primarily by plant leaves, with the small amount that reached the sediment hydrolyzing rapidly. Six months after spraying, however, total macrofauna in treated plots was more than four times more abundant than in unsprayed control plots, due to a fifteen-fold increase in annelids. This population growth correlated with increased sedimentary organic matter in treated plots, likely due to decomposition of dead S. anglica leaves serving as food for annelids. After another year, no differences in macrofauna or organic matter remained between treatments. The indirect effect on annelid populations from herbicide treatment could benefit management efforts by providing greater food resources for wading birds, in addition to improving birds' access to sediments by reducing plant cover. This study shows that an invasive grass can have a significant impact on native fauna through food-web interactions, influenced by herbicide usage.

  18. Fragments of the key flowering gene GIGANTEA are associated with helitron-type sequences in the Pooideae grass Lolium perenne

    Directory of Open Access Journals (Sweden)

    Langdon Tim

    2009-06-01

    Full Text Available Abstract Background Helitrons are a class of transposable elements which have been identified in a number of species of plants, animals and fungi. They are unique in their proposed rolling-circle mode of replication, have a highly variable copy-number and have been implicated in the restructuring of coding sequences both by their insertion into existing genes and by their incorporation of transcriptionally competent gene fragments. Helitron discovery depends on identifying associated DNA signature sequences and comprehensive evaluation of helitron contribution to a particular genome requires detailed computational analysis of whole genome sequence. Therefore, the role which helitrons have played in modelling non-model plant genomes is largely unknown. Results Cloning of the flowering gene GIGANTEA (GI from a BAC library of the Pooideae grass Lolium perenne (perennial ryegrass identified the target gene and several GI pseudogene fragments spanning the first five exons. Analysis of genomic sequence 5' and 3' of one these GI fragments revealed motifs consistent with helitron-type transposon insertion, specifically a putative 5'-A↓T-3' insertion site containing 5'-TC and CTAG-3' borders with a sub-terminal 16 bp hairpin. Screening of a BAC library of the closely related grass species Festuca pratensis (meadow fescue indicated similar helitron-associated GI fragments present in this genome, as well as non-helitron associated GI fragments derived from the same region of GI. In order to investigate the possible extent of ancestral helitron-activity in L. perenne, a methylation-filtered GeneThresher® genomic library developed from this species was screened for potential helitron 3' hairpin sequences associated with a 3'-CTRR motif. This identified 7 potential helitron hairpin-types present between at least 9 and 51 times within the L. perenne methylation-filtered library. Conclusion This represents evidence for a possible ancestral role for helitrons

  19. Composition and architecture of the cell walls of grasses and the mechanisms of synthesis of cell wall polysaccharides. Final report for period September 1, 1988 - April 30, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas C.

    2001-10-18

    This program was devoted toward complete understanding of the polysaccharide structure and architecture of the primary cell walls grasses and cereals, and the biosynthesis of the mixed-linkage beta-glucane, a cellulose interacting polymer that is synthesized uniquely by grass species and close relatives. With these studies as focal point, the support from DOE was instrumental in the development of new analytical means that enabled us to characterize carbohydrate structure, to reveal new features of cell wall dynamics during cell growth, and to apply these techniques in other model organisms. The support by DOE in these basic studies was acknowledged on numerous occasions in review articles covering current knowledge of cell wall structure, architecture, dynamics, biosynthesis, and in all genes related to cell wall biogenesis.

  20. Biogas from grass silage - Measurements and modeling with ADM1.

    Science.gov (United States)

    Koch, Konrad; Lübken, Manfred; Gehring, Tito; Wichern, Marc; Horn, Harald

    2010-11-01

    Mono fermentation of grass silage without the addition of manure was performed over a period of 345days under mesophilic conditions (38 degrees C). A simulation study based on the IWA Anaerobic Digestion Model No. 1 (ADM1) was done in order to show its applicability to lignocellulosic biomass. Therefore, the influent was fractioned by established fodder analysis (Weender analysis and van Soest method). ADM1 was modified with a separate compound of inert decay products similar to the approach of Activated Sludge Model No. 1 (ASM1). Furthermore, a function, which described the influence of solids on the process of hydrolysis, has been integrated to reproduce reliable ammonium concentrations. The model was calibrated by using the modified Nash-Sutcliffe coefficient to evaluate simulation quality. It was possible to fit observed data by changing only hydrogen inhibition constants and the maximum acetate uptake rate. The extended ADM1 model showed good agreement with measurements and was suitable for modeling anaerobic digestion of grass silage.