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Sample records for grass species belonging

  1. Soil nitrogen mineralization not affected by grass species traits

    Science.gov (United States)

    Maged Ikram Nosshi; Jack Butler; M. J. Trlica

    2007-01-01

    Species N use traits was evaluated as a mechanism whereby Bromus inermis (Bromus), an established invasive, might alter soil N supply in a Northern mixed-grass prairie. We compared soils under stands of Bromus with those from three representative native grasses of different litter C/N: Andropogon...

  2. Grass pollen immunotherapy induces highly cross-reactive IgG antibodies to group V allergen from different grass species

    NARCIS (Netherlands)

    van Ree, R.; Brewczyński, P. Z.; Tan, K. Y.; Mulder-Willems, H. J.; Widjaja, P.; Stapel, S. O.; Aalberse, R. C.; Kroon, A. M.

    1995-01-01

    Sera from two groups of patients receiving grass pollen immunotherapy were tested on IgG reactivity with group V allergen from six different grass species. One group of patients was treated with a mixture of 10 grass species, and the other with a mixture of five. Only Lolium perenne, Dactylis

  3. Grass species selection patterns on rotationally-grazed Dohne ...

    African Journals Online (AJOL)

    Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

  4. Short Communication: Autelogical studies on grass species in ...

    African Journals Online (AJOL)

    A literature survey of autecological studies on southern African grass species was undertaken. Results revealed that there is a comparative lack of autecological versus community studies. Where autecological studies have been conducted, most of the attention was focused on 'pasture' or 'desirable' species with ...

  5. Adaptation of a decreaser and an increaser grass species to ...

    African Journals Online (AJOL)

    Grasses have developed through natural selection to deter, escape and tolerate herbivory, and to escape and tolerate fire. In the semi-arid grassveld of the Eastern Cape, the species Themeda triandra and Sporobolus fimbriatus have been classified as Decreaser and Increaser II plants respectively. Both species have ...

  6. Responses of three grass species to creosote during phytoremediation

    International Nuclear Information System (INIS)

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

    2004-01-01

    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

  7. Indirect effects of an invasive annual grass on seed fates of two native perennial grass species.

    Science.gov (United States)

    Meyer, Susan E; Merrill, Katherine T; Allen, Phil S; Beckstead, Julie; Norte, Anna S

    2014-04-01

    Invasive plants exhibit both direct and indirect negative effects on recruitment of natives following invasion. We examined indirect effects of the invader Bromus tectorum (cheatgrass) on seed fates of two native grass species, Elymus elymoides and Pseudoroegneria spicata, by removing B. tectorum and by adding inoculum of the shared seed pathogen Pyrenophora semeniperda in factorial experiments at xeric and mesic field sites. We also included a supplemental watering treatment to increase emergence and also the potential for pathogen escape. We recorded emergence and survival of native seedlings and also determined the fate of unemerged seeds. At the xeric site, Pyrenophora-caused mortality was high (34%), and effects of other pathogens and failed emergence of germinants were smaller. Cheatgrass removal negatively affected both emergence (35 vs. 25%) and spring survival (69 vs. 42%). Pyrenophora-caused seed mortality increased with inoculum augmentation for both species (22 vs. 47% overall), but emergence was negatively impacted only for P. spicata (20 vs. 34%). At the mesic site, Pyrenophora-caused mortality was low (6%). Cheatgrass removal doubled emergence (26 vs. 14%). Seed mortality increased significantly with inoculum augmentation for P. spicata (12 vs. 5%) but not E. elymoides, while emergence was not significantly affected in either species. A large fraction of seeds produced germinants that failed to emerge (37%), while another large fraction (35%) was killed by other pathogens. We conclude that facilitation by cheatgrass at the xeric site but interference at the mesic site was probably mediated through litter effects that could be ameliorative or suppressive. Apparent competition between cheatgrass and native grasses could occur through Pyrenophora, especially in a xeric environment, but effects were weak or absent at emergence. This was probably because Pyrenophora attacks the same slow-germinating fraction that is subject to pre-emergence mortality from

  8. Effect of grass species on NDF ruminal degradability and ...

    African Journals Online (AJOL)

    uzivatel

    Abstract. The objective of this study was to compare the ruminal degradability of neutral detergent fibre (NDF) .... Felina were evaluated in the present study. The grass was harvested from the primary growth of monocultured grasses on 19 and 26 May of 2004 and 27 May and 10 ...... Nutritional Ecology of the Ruminant.

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

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    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

  10. Optimal prescribed burn frequency to manage foundation California perennial grass species and enhance native flora

    Science.gov (United States)

    Grasslands can be diverse assemblages of grasses and forbs but not much is known how perennial grass species management affects native plant diversity except for in a few instances. We studied the use of late spring prescribed burns over a span of eleven years on experimental plots in which the pere...

  11. 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.

  12. Korean indigenous bacterial species with valid names belonging to the phylum Actinobacteria.

    Science.gov (United States)

    Bae, Kyung Sook; Kim, Mi Sun; Lee, Ji Hee; Kang, Joo Won; Kim, Dae In; Lee, Ji Hee; Seong, Chi Nam

    2016-12-01

    To understand the isolation and classification state of actinobacterial species with valid names for Korean indigenous isolates, isolation source, regional origin, and taxonomic affiliation of the isolates were studied. At the time of this writing, the phylum Actinobacteria consisted of only one class, Actinobacteria, including five subclasses, 10 orders, 56 families, and 330 genera. Moreover, new taxa of this phylum continue to be discovered. Korean actinobacterial species with a valid name has been reported from 1995 as Tsukamurella inchonensis isolated from a clinical specimen. In 1997, Streptomyces seoulensis was validated with the isolate from the natural Korean environment. Until Feb. 2016, 256 actinobacterial species with valid names originated from Korean territory were listed on LPSN. The species were affiliated with three subclasses (Acidimicrobidae, Actinobacteridae, and Rubrobacteridae), four orders (Acidimicrobiales, Actinomycetales, Bifidobacteriales, and Solirubrobacterales), 12 suborders, 36 families, and 93 genera. Most of the species belonged to the subclass Actinobacteridae, and almost of the members of this subclass were affiliated with the order Actinomycetales. A number of novel isolates belonged to the families Nocardioidaceae, Microbacteriaceae, Intrasporangiaceae, and Streptomycetaceae as well as the genera Nocardioides, Streptomyces, and Microbacterium. Twenty-six novel genera and one novel family, Motilibacteraceae, were created first with Korean indigenous isolates. Most of the Korean indigenous actionobacterial species were isolated from natural environments such as soil, seawater, tidal flat sediment, and fresh-water. A considerable number of species were isolated from artificial resources such as fermented foods, wastewater, compost, biofilm, and water-cooling systems or clinical specimens. Korean indigenous actinobacterial species were isolated from whole territory of Korea, and especially a large number of species were from Jeju

  13. Tuber aztecorum sp. nov., a truffle species from Mexico belonging to the Maculatum clade (Tuberaceae, Pezizales

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    Gonzalo Guevara-Guerrero

    2018-02-01

    Full Text Available A new species of truffle, T. aztecorum, is described from central Mexico. Tuber aztecorum can be distinguished from other related Tuber species synoptically by a combination of morphological features including ascospore size, pellis cells with irregular thickness, cystidia, ascoma colour and associated host (Abies religiosa an endemic Abies species from central Mexico; sequence variation on the ITS rDNA also distinguishes T. aztecorum from related species. A phylogenetic analysis of the ITS rDNA demonstrates that T. aztecorum belongs to the Maculatum clade and is unique from other similar small, white-cream coloured Tuber species distributed in north-eastern Mexico such as T. castilloi and T. guevarai.

  14. Four New Ladybug Species Belonging to Decadiomus Chapin (Coleoptera: Coccinellidae) from Puerto Rico.

    Science.gov (United States)

    Segarra-Carmona, A E; Otero, M

    2014-12-01

    While searching for native natural enemies attacking invasive insect pests in Puerto Rico, we found four undescribed ladybug species belonging to the Caribbean ladybug genus Decadiomus Chapin. In this article, we describe the following species from Puerto Rico: Decadiomus seini n. sp., Decadiomus ramosi n. sp., Decadiomus hayuyai n. sp., and Decadiomus martorelli n. sp. Illustrations of the dorsal habitus, shape of prosternal carinae, and drawings of male and female genitalia are presented. We also present a key for Diomini of Puerto Rico and discuss their importance as potential biocontrol agents.

  15. BOX-PCR-based identification of bacterial species belonging to Pseudomonas syringae: P. viridiflava group

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    Abi S.A. Marques

    2008-01-01

    Full Text Available The phenotypic characteristics and genetic fingerprints of a collection of 120 bacterial strains, belonging to Pseudomonas syringae sensu lato group, P. viridiflava and reference bacteria were evaluated, with the aim of species identification. The numerical analysis of 119 nutritional characteristics did not show patterns that would help with identification. Regarding the genetic fingerprinting, the results of the present study supported the observation that BOX-PCR seems to be able to identify bacterial strains at species level. After numerical analyses of the bar-codes, all pathovars belonging to each one of the nine described genomospecies were clustered together at a distance of 0.72, and could be separated at genomic species level. Two P. syringae strains of unknown pathovars (CFBP 3650 and CFBP 3662 and the three P. syringae pv. actinidiae strains were grouped in two extra clusters and might eventually constitute two new species. This genomic species clustering was particularly evident for genomospecies 4, which gathered P. syringae pvs. atropurpurea, coronafaciens, garçae, oryzae, porri, striafaciens, and zizaniae at a noticeably low distance.

  16. GeMprospector--online design of cross-species genetic marker candidates in legumes and grasses.

    Science.gov (United States)

    Fredslund, Jakob; Madsen, Lene H; Hougaard, Birgit K; Sandal, Niels; Stougaard, Jens; Bertioli, David; Schauser, Leif

    2006-07-01

    The web program GeMprospector (URL: http://cgi-www.daimi.au.dk/cgi-chili/GeMprospector/main) allows users to automatically design large sets of cross-species genetic marker candidates targeting either legumes or grasses. The user uploads a collection of ESTs from one or more legume or grass species, and they are compared with a database of clusters of homologous EST and genomic sequences from other legumes or grasses, respectively. Multiple sequence alignments between submitted ESTs and their homologues in the appropriate database form the basis of automated PCR primer design in conserved exons such that each primer set amplifies an intron. The only user input is a collection of ESTs, not necessarily from more than one species, and GeMprospector can boost the potential of such an EST collection by combining it with a large database to produce cross-species genetic marker candidates for legumes or grasses.

  17. Feed intake and milk production in dairy cows fed different grass and legume species: a meta-analysis

    DEFF Research Database (Denmark)

    Johansen, Marianne; Lund, Peter; Weisbjerg, Martin Riis

    2018-01-01

    The aim of this meta-analysis was to compare feed intake, milk production, milk composition and organic matter (OM) digestibility in dairy cows fed different grass and legume species. Data from the literature was collected and different data sets were made to compare families (grasses v. legumes...... tannins in birdsfoot trefoil. None of the included grass species differed in DMI, milk production, milk composition or OM digestibility, indicating that different grass species have the same value for milk production, if OM digestibility is comparable. However, the comparison of different grass species...

  18. Lectotypification of three Iberian endemic species belonging to monotypic genera described by Cosson

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    Buira, Antoni

    2015-12-01

    Full Text Available Three lectotypes are here designated for Euzomodendron bourgaeanum Coss., Guiraoa arvensis Coss. and Laserpitium scabrum Cav. (Guillonea scabra (Cav. Coss., whose genera are monospecific and endemic to the Iberian Peninsula. The selected types of the two former species are kept at P and belong to Cosson’s personal herbarium, whilst the last one is kept at MA and belongs to the historical herbarium of Cavanilles.Se designan los lectótipos de Euzomodendron bourgaeanum Coss., Guiraoa arvensis Coss. y Laserpitium scabrum Cav. (Guillonea scabra (Cav. Coss., cuyos géneros son monoespecíficos y endémicos de la Península Ibérica. Los tipos seleccionados para las dos primeras especies se encuentran en P y pertenecen al herbario personal de Cosson, mientras que el de la última se encuentra en MA y pertenece al herbario histórico de Cavanilles.

  19. A key to larvae of species belonging to the genus Diamesa from Alps and Apennines (Italy

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    Bruno Rossaro

    2015-07-01

    Full Text Available A key to species belonging to the genus Diamesa Meigen, 1835 (Diptera, Chironomidae from the Alps and Apennines (Italy is presented using characters observable in the fourth-instar larva. The larvae are separated on the basis of qualitative and quantitative characters. At present fifteen species from the Italian Alps are described in all three life stages, but only twelve species groups can be separated as larvae. The separation is based on the length and thickness of anal setae, antennal ratio, head capsule color and few other characters of the labrum and mentum. The shape of mental and mandibular teeth is still a valid taxonomic character, but unfortunately these characters can be rarely used because teeth are often excessively worn in samples collected in the field. Quantitative characters show variability within each species, differing according to the duration of larval development and must be used with caution. The species groups which can be separated in the larval stage are: the dampfi group, which includes D. dampfi and D. permacra, the latitarsis group including D. modesta and D. latitarsis, the zernyi group including D. zernyi and D. vaillanti. The species within each of these groups at present cannot be separated. D. starmachi, D. steinboecki, D. goetghebueri, D. bertrami, D. aberrata, D. incallida, D. cinerella, D. tonsa and D. insignipes can be separated from all the other known species in larval stage.

  20. Bacterial endophyte communities of three agricultural important grass species differ in their response towards management regimes

    Science.gov (United States)

    Wemheuer, Franziska; Kaiser, Kristin; Karlovsky, Petr; Daniel, Rolf; Vidal, Stefan; Wemheuer, Bernd

    2017-01-01

    Endophytic bacteria are critical for plant growth and health. However, compositional and functional responses of bacterial endophyte communities towards agricultural practices are still poorly understood. Hence, we analyzed the influence of fertilizer application and mowing frequency on bacterial endophytes in three agriculturally important grass species. For this purpose, we examined bacterial endophytic communities in aerial plant parts of Dactylis glomerata L., Festuca rubra L., and Lolium perenne L. by pyrotag sequencing of bacterial 16S rRNA genes over two consecutive years. Although management regimes influenced endophyte communities, observed responses were grass species-specific. This might be attributed to several bacteria specifically associated with a single grass species. We further predicted functional profiles from obtained 16S rRNA data. These profiles revealed that predicted abundances of genes involved in plant growth promotion or nitrogen metabolism differed between grass species and between management regimes. Moreover, structural and functional community patterns showed no correlation to each other indicating that plant species-specific selection of endophytes is driven by functional rather than phylogenetic traits. The unique combination of 16S rRNA data and functional profiles provided a holistic picture of compositional and functional responses of bacterial endophytes in agricultural relevant grass species towards management practices.

  1. 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.

  2. 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.

  3. Variability of Pyrrolizidine Alkaloid Occurrence in Species of the Grass Subfamily Pooideae (Poaceae)

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    Wesseling, Anne-Maria; Demetrowitsch, Tobias J.; Schwarz, Karin; Ober, Dietrich

    2017-01-01

    Pyrrolizidine alkaloids (PAs) are a class of secondary metabolites found in various unrelated angiosperm lineages including cool-season grasses (Poaceae, subfamily Pooideae). Thesinine conjugates, saturated forms of PA that are regarded as non-toxic, have been described to occur in the two grass species Lolium perenne and Festuca arundinacea (Poaceae, subfamily Pooideae). In a wider screen, we tested various species of the Pooideae lineage, grown under controlled conditions, for their ability to produce thesinine conjugates or related structures. Using an LC-MS based targeted metabolomics approach we were able to show that PA biosynthesis in grasses is limited to a group of very closely related Pooideae species that produce a limited diversity of PA structures. High variability in PA levels was observed even between individuals of the same species. These individual accumulation patterns are discussed with respect to a possible function and evolution of this type of alkaloid. PMID:29250094

  4. Variability of Pyrrolizidine Alkaloid Occurrence in Species of the Grass Subfamily Pooideae (Poaceae

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    Anne-Maria Wesseling

    2017-11-01

    Full Text Available Pyrrolizidine alkaloids (PAs are a class of secondary metabolites found in various unrelated angiosperm lineages including cool-season grasses (Poaceae, subfamily Pooideae. Thesinine conjugates, saturated forms of PA that are regarded as non-toxic, have been described to occur in the two grass species Lolium perenne and Festuca arundinacea (Poaceae, subfamily Pooideae. In a wider screen, we tested various species of the Pooideae lineage, grown under controlled conditions, for their ability to produce thesinine conjugates or related structures. Using an LC-MS based targeted metabolomics approach we were able to show that PA biosynthesis in grasses is limited to a group of very closely related Pooideae species that produce a limited diversity of PA structures. High variability in PA levels was observed even between individuals of the same species. These individual accumulation patterns are discussed with respect to a possible function and evolution of this type of alkaloid.

  5. 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.

  6. Endophytic Epichloë species and their grass hosts: from evolution to applications.

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    Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L

    2016-04-01

    The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.

  7. Phytotoxic activity against Bromus tectorum for secondary metabolites of a seed-pathogenic Fusarium strain belonging to the F. tricinctum species complex.

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    Masi, Marco; Meyer, Susan; Pescitelli, Gennaro; Cimmino, Alessio; Clement, Suzette; Peacock, Beth; Evidente, Antonio

    2017-12-01

    The winter annual grass Bromus tectorum (cheatgrass) has become highly invasive in semiarid ecosystems of western North America. In these areas, a natural phenomenon, complete cheatgrass stand failure ('die-off'), is apparently caused by a complex interaction among soilborne fungal pathogens. Several Fusarium strains belonging to the Fusarium tricinctum species complex were isolated from these soils and found to be pathogenic on B. tectorum seeds. One of these strains was produced in cheatgrass seed culture to evaluate its ability to produce phytotoxins. Six metabolites were isolated and identified by spectroscopic methods (essentially 1D and 2D NMR and ESIMS) as acuminatopyrone (1), blumenol A (2), chlamydosporol (3), isochlamydosporol (4), ergosterol (5) and 4-hydroxybenzaldehyde (6). Upon testing against B. tectorum in a seedling bioassay, (6) the coleoptile and radicle length of cheatgrass seedlings were significantly reduced. Compounds 1 and 2 showed moderate activity, while 3-5 were not significantly different from the control.

  8. 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 .

  9. Soil nutrient heterogeneity alters competition between two perennial grass species

    NARCIS (Netherlands)

    Fransen, B.; Kroon, de H.; Berendse, F.

    2001-01-01

    Differences in root foraging behavior between species have been well documented, but the effects of these differences on belowground competitive ability are only beginning to be studied. Here we report the results of a competition experiment in homogeneous and heterogeneous soils between two species

  10. MT and WY Tamarix soil properties influence germination and early growth of three native grass species

    Science.gov (United States)

    As a riparian invader, Tamarix spp. often leads to native species (e.g., plains cottonwood and willows, grasses) decline and lower habitat quality. Since Tamarix excretes excess salt and has high salt tolerance, negative soil feedback via high soil salinity may negatively affect native plants. Howev...

  11. Changes of biomass in some perennial grass species. | M.C. ...

    African Journals Online (AJOL)

    Patterns of seasonal herbaceous biomass change in a burned, ungrazed savanna woodland are reported. A standard clipping technique was used and material farmed in the current season was separated from that formed in the previous season for three perennial grass species: Brachiaria nigropedata, Andropogon ...

  12. Comparison of arsenic uptake ability of barnyard grass and rice species for arsenic phytoremediation.

    Science.gov (United States)

    Sultana, Razia; Kobayashi, Katsuichiro; Kim, Ki-Hyun

    2015-01-01

    In this research, the relative performance in arsenic (As) remediation was evaluated among some barnyard grass and rice species under hydroponic conditions. To this end, four barnyard grass varieties and two rice species were selected and tested for their remediation potential of arsenic. The plants were grown for 2 weeks in As-rich solutions up to 10 mg As L(-1) to measure their tolerance to As and their uptake capabilities. Among the varieties of plants tested in all treatment types, BR-29 rice absorbed the highest amount of As in the root, while Nipponbare translocated the maximum amount of As in the shoot. Himetainubie barnyard grass produced the highest biomass, irrespective of the quantity of As in the solution. In all As-treated solutions, the maximum uptake of As was found in BR-29 followed by Choto shama and Himetainubie. In contrast, while the bioaccumulation factor was found to be the highest in Nipponbare followed by BR-29 and Himetainubie. The results suggest that both Choto shama and Himetainubie barnyard grass varieties should exhibit a great potential for As removal, while BR-29 and Nipponbare rice species are the best option for arsenic phytoremediation.

  13. Management techniques for the control of Melinis minutiflora P. Beauv. (molasses grass: ten years of research on an invasive grass species in the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Carlos Romero Martins

    2017-09-01

    Full Text Available ABSTRACT The invasion of exotic species is considered to be a major threat to the preservation of biodiversity. In the Parque Nacional de Brasília (National Park of Brasília, the invasive Melinis minutiflora (molasses grass occupies more than 10 % of the area of the park. The present, long-term, study compared two treatments of exposure to molasses grass: 1 fire and 2 integrated management (fire + herbicide sprays + manual removal. The aerial biomass of molasses grass in the experimental area initially represented ca. 55 % of the total aerial biomass, a percentage that apparently did not influence native plant species richness at this site. Fire alone was not sufficient to control molasses grass, which attained its pre-treatment biomass values after two years. Integrated management reduced, and maintained, biomass to less than 1 % of its original value after ten years, and maintained this level throughout the study, demonstrating that it is a promising strategy for the recovery of areas invaded by molasses grass in the Cerrado. However, because of the recolonization by molasses grass, long-term monitoring efforts are targeting outbreaks, which would require immediate intervention in order to maintain the native biological diversity of the region.

  14. In vitro antifungal susceptibility of clinical species belonging to Aspergillus genus and Rhizopus oryzae.

    Science.gov (United States)

    Kachuei, R; Khodavaisy, S; Rezaie, S; Sharifynia, S

    2016-03-01

    Among filamentous fungal pathogens, Aspergillus spp. and zygomycetes account for highest rates of morbidity and mortality among immunocompromised patients. Recently developed antifungal drugs offer the potential to improve management and therapeutic outcomes of fungal infections. The aim of this study was to analyse the in vitro activities of voriconazole, itraconazole, amphotericin B and caspofungin against clinical isolates of Aspergillus spp. and Rhizopus oryzae. The in vitro antifungal susceptibility of 54 isolates belonging to different clinical isolates of Aspergillus spp. and R. oryzae was tested for four antifungal agents using a microdilution reference method (CLSI, M38-A2). All isolates were identified by typical colony and microscopic characteristics, and also characterized by molecular methods. Caspofungin (MEC range: 0.008-0.25 and MEC50: 0.0023μg/mL) was the most active drug in vitro against Aspergillus spp., followed by voriconazole (MIC range: 0.031-8 and MIC50: 0.5μg/mL), itraconazole (MIC range: 0.031-16 and MIC50: 0.25μg/mL), and amphotericin B (MIC range: 0.125-4 and MIC50: 0.5μg/mL), in order of decreasing activity. The caspofungin, voriconazole, and itraconazole demonstrated poor in vitro activity against R. oryzae isolates evaluated, followed by amphotericin B. This study demonstrates that caspofungin had good antifungal activity and azole agents had better activity than amphotericin B against Aspergillus species. Although, azole drugs are considered ineffective against R. oryzae. This result is just from a small scale in vitro susceptibility study and we did not take other factors into consideration. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Interactive effects of plant-available soil silicon and herbivory on competition between two grass species

    Science.gov (United States)

    Garbuzov, Mihail; Reidinger, Stefan; Hartley, Susan E.

    2011-01-01

    Background and Aims The herbivore defence system of true grasses (Poaceae) is predominantly based on silicon that is taken up from the soil and deposited in the leaves in the form of abrasive phytoliths. Silicon uptake mechanisms can be both passive and active, with the latter suggesting that there is an energetic cost to silicon uptake. This study assessed the effects of plant-available soil silicon and herbivory on the competitive interactions between the grasses Poa annua, a species that has previously been reported to accumulate only small amounts of silicon, and Lolium perenne, a high silicon accumulator. Methods Plants were grown in mono- and mixed cultures under greenhouse conditions. Plant-available soil silicon levels were manipulated by adding silicon to the soil in the form of sodium silicate. Subsets of mixed culture pots were exposed to above-ground herbivory by desert locusts (Schistocerca gregaria). Key Results In the absence of herbivory, silicon addition increased biomass of P. annua but decreased biomass of L. perenne. Silicon addition increased foliar silicon concentrations of both grass species >4-fold. Under low soil-silicon availability the herbivores removed more leaf biomass from L. perenne than from P. annua, whereas under high silicon availability the reverse was true. Consequently, herbivory shifted the competitive balance between the two grass species, with the outcome depending on the availability of soil silicon. Conclusions It is concluded that a complex interplay between herbivore abundance, growth–defence trade-offs and the availability of soil silicon in the grasses' local environment affects the outcome of inter-specific competition, and so has the potential to impact on plant community structure. PMID:21868406

  16. Complementary DNA cloning of the major allergen Phl p I from timothy grass (Phleum pratense); recombinant Phl p I inhibits IgE binding to group I allergens from eight different grass species

    NARCIS (Netherlands)

    Laffer, S.; Valenta, R.; Vrtala, S.; Susani, M.; van Ree, R.; Kraft, D.; Scheiner, O.; Duchêne, M.

    1994-01-01

    BACKGROUND: Grass pollens, such as pollen from timothy grass (Phleum pratense), represent a major cause of type I allergy. OBJECTIVE: In this report we attempted to determine how cross-reactive allergenic components of grass pollens from different species can be represented by a minimum number of

  17. Plastome Sequence Determination and Comparative Analysis for Members of the Lolium-Festuca Grass Species Complex

    OpenAIRE

    Hand, Melanie L.; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

    2013-01-01

    Chloroplast genome sequences are of broad significance in plant biology, due to frequent use in molecular phylogenetics, comparative genomics, population genetics, and genetic modification studies. The present study used a second-generation sequencing approach to determine and assemble the plastid genomes (plastomes) of four representatives from the agriculturally important Lolium-Festuca species complex of pasture grasses (Lolium multiflorum, Festuca pratensis, Festuca altissima, and Festuca...

  18. Plastome Sequence Determination and Comparative Analysis for Members of the Lolium-Festuca Grass Species Complex

    Science.gov (United States)

    Hand, Melanie L.; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

    2013-01-01

    Chloroplast genome sequences are of broad significance in plant biology, due to frequent use in molecular phylogenetics, comparative genomics, population genetics, and genetic modification studies. The present study used a second-generation sequencing approach to determine and assemble the plastid genomes (plastomes) of four representatives from the agriculturally important Lolium-Festuca species complex of pasture grasses (Lolium multiflorum, Festuca pratensis, Festuca altissima, and Festuca ovina). Total cellular DNA was extracted from either roots or leaves, was sequenced, and the output was filtered for plastome-related reads. A comparison between sources revealed fewer plastome-related reads from root-derived template but an increase in incidental bacterium-derived sequences. Plastome assembly and annotation indicated high levels of sequence identity and a conserved organization and gene content between species. However, frequent deletions within the F. ovina plastome appeared to contribute to a smaller plastid genome size. Comparative analysis with complete plastome sequences from other members of the Poaceae confirmed conservation of most grass-specific features. Detailed analysis of the rbcL–psaI intergenic region, however, revealed a “hot-spot” of variation characterized by independent deletion events. The evolutionary implications of this observation are discussed. The complete plastome sequences are anticipated to provide the basis for potential organelle-specific genetic modification of pasture grasses. PMID:23550121

  19. Efficacy of Biosolids in Assisted Phytostabilization of Metalliferous Acidic Sandy Soils with Five Grass Species

    Science.gov (United States)

    Kacprzak, Malgorzata; Grobelak, Anna; Grosser, Anna; Prasad, M. N. V.

    2013-01-01

    The role of sewage sludge as an immobilising agent in the phytostabilization of metal-contaminated soil was evaluated using five grass species viz., Dactylis glomerata L., Festuca arundinacea Schreb., F. rubra L., Lolium perenne L., L. westerwoldicum L. The function of metal immobilization was investigated by monitoring pH, Eh and Cd, Pb, and Zn levels in column experiment over a period of 5-months. Grasses grown on sewage sludge-amendments produced high biomass in comparison to controls. A significant reduction in metal uptake by plants was also observed as a result of sewage sludge application, which was attributed to decreased bioavailability through soil stabilisation. We have observed that the sludge amendment decreased metal bioavailability and concentrations in soil at a depth of 25 cm, in contrast to untreated columns, where metal concentrations in the soil solution were very high. PMID:24912245

  20. [A comparative study on seed germination of 15 grass species in Keeqin Sandyland].

    Science.gov (United States)

    Liu, Zhimin; Li, Xuehua; Li, Rongping; Jiang, Deming; Cao, Chengyou

    2003-09-01

    A laboratory study was made on the germination characteristics of freshly-collected seeds of grass species at the Wulanaodu area of Keeqin Sandyland in Eastern Inner-Mongolia. Of the 15 species examined, 8 species including Clinelymus dahuricus, Cleistogenes squarrosa, Pappophorum boreale, Spodiopogon sibiricus, Phragmites communis, Chloris virgata, Arundinella hirta, Pennisetum alopecuroides had a germination rate of over 80%, but 4 species including Echinochloa hispidula, Hemarthria compressa, Tragus berteronianus and Setaria viridis had a value of less than 10%. Spodiopogon sibiricus, Eragrostis pilosa, Phragmites communis, Chloris virgata, Clinelymus dahuricus, Pappophorum boreale, Digitaria cilliaris and Cleistogenes squrrosa began to germinate within 1-3 days after the test began, while Setaria viridis, Tragus berteronianus and Hemarthria compressa failed to germinate in a period of more than 10 days. For the species such as Digitaria cilliaris, Echinochloa hispidula, Phragmites communis, Eragrostis pilosa and Spodiopogon sibiricus, their germination period was less than 10 days, while Clinelymus dahuricus and Pappophorum boreale had a germination period of more than 20 days. The days required for half the final germination rate to be reached were: 2 days for Chloris virgata, 3 days for Phragmites communis, 4 days for Spodiopogon sibiricus, 5 days for Clinelymus dahuricus and Cleistogenes squarrosa, 7 days for Arundinella hirta and Pappophorum boreale, and 10 days for Pennisetum alopecuriodes. Compared with the Sheffield region in Britain, the Wulanaodu area of Kerqin Sandyland had a higher proportion of annul grasses with a low germination rate and a longer germination period, and the perennial grasses at the Wulanaodu area had an approximately same germination rate, but a longer germination period. During germination, ruderals showed the potential for risk-sharring, and thus, they had a relatively higher disturbance-resistance capacity.

  1. Oxygen isotope fractionations across individual leaf carbohydrates in grass and tree species.

    Science.gov (United States)

    Lehmann, Marco M; Gamarra, Bruno; Kahmen, Ansgar; Siegwolf, Rolf T W; Saurer, Matthias

    2017-08-01

    Almost no δ 18 O data are available for leaf carbohydrates, leaving a gap in the understanding of the δ 18 O relationship between leaf water and cellulose. We measured δ 18 O values of bulk leaf water (δ 18 O LW ) and individual leaf carbohydrates (e.g. fructose, glucose and sucrose) in grass and tree species and δ 18 O of leaf cellulose in grasses. The grasses were grown under two relative humidity (rH) conditions. Sucrose was generally 18 O-enriched compared with hexoses across all species with an apparent biosynthetic fractionation factor (ε bio ) of more than 27‰ relative to δ 18 O LW , which might be explained by isotopic leaf water and sucrose synthesis gradients. δ 18 O LW and δ 18 O values of carbohydrates and cellulose in grasses were strongly related, indicating that the leaf water signal in carbohydrates was transferred to cellulose (ε bio  = 25.1‰). Interestingly, damping factor p ex p x , which reflects oxygen isotope exchange with less enriched water during cellulose synthesis, responded to rH conditions if modelled from δ 18 O LW but not if modelled directly from δ 18 O of individual carbohydrates. We conclude that δ 18 O LW is not always a good substitute for δ 18 O of synthesis water due to isotopic leaf water gradients. Thus, compound-specific δ 18 O analyses of individual carbohydrates are helpful to better constrain (post-)photosynthetic isotope fractionation processes in plants. © 2017 John Wiley & Sons Ltd.

  2. 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.

  3. 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.

  4. 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.

  5. Soil modification by invasive plants: Effects on native and invasive species of mixed-grass prairies

    Science.gov (United States)

    Jordan, N.R.; Larson, D.L.; Huerd, S.C.

    2008-01-01

    Invasive plants are capable of modifying attributes of soil to facilitate further invasion by conspecifics and other invasive species. We assessed this capability in three important plant invaders of grasslands in the Great Plains region of North America: leafy spurge (Euphorbia esula), smooth brome (Bromus inermis) and crested wheatgrass (Agropyron cristatum). In a glasshouse, these three invasives or a group of native species were grown separately through three cycles of growth and soil conditioning in both steam-pasteurized and non-pasteurized soils, after which we assessed seedling growth in these soils. Two of the three invasive species, Bromus and Agropyron, exhibited significant self-facilitation via soil modification. Bromus and Agropyron also had significant facilitative effects on other invasives via soil modification, while Euphorbia had significant antagonistic effects on the other invasives. Both Agropyron and Euphorbia consistently suppressed growth of two of three native forbs, while three native grasses were generally less affected. Almost all intra- and interspecific effects of invasive soil conditioning were dependent upon presence of soil biota from field sites where these species were successful invaders. Overall, these results suggest that that invasive modification of soil microbiota can facilitate plant invasion directly or via 'cross-facilitation' of other invasive species, and moreover has potential to impede restoration of native communities after removal of an invasive species. However, certain native species that are relatively insensitive to altered soil biota (as we observed in the case of the forb Linum lewisii and the native grasses), may be valuable as 'nurse'species in restoration efforts. ?? 2007 Springer Science+Business Media B.V.

  6. Seed size and photoblastism in species belonging to tribe Cacteae (Cactaceae).

    Science.gov (United States)

    Rojas-Aréchiga, Mariana; Mandujano, María C; Golubov, Jordan K

    2013-05-01

    The response of seed germination towards light and the relationship to seed traits has been studied particularly well in tropical forests. Several authors have shown a clear adaptive response of seed size and photoblastism, however, the evolutionary significance of this relationship for species inhabiting arid environments has not been fully understood and only some studies have considered the response in a phylogenetic context. We collected seeds from 54 cacti species spread throughout the tribe Cacteae to test whether there was correlated evolution of photoblastism, seed traits and germination using a reconstructed phylogeny of the tribe. For each species we determined the photoblastic response under controlled conditions, and seed traits, and analyzed the results using phylogenetically independent contrasts. All studied species were positive photoblastic contrasting with the basal Pereskia suggesting an early evolution of this trait. Seeds from basal species were mostly medium-sized, diverging into two groups. Seeds tend to get smaller and lighter suggesting an evolution to smaller sizes. No evidence exists of a relationship between seed size and photoblastic response suggesting that the photoblastic response within members of this tribe is not adaptive though it is phylogenetically fixed and that is coupled with environmental cues that fine tune the germination response.

  7. N transfer in three species grass-clover mixtures with chicory, ribwort plantain or caraway

    DEFF Research Database (Denmark)

    Dhamala, Nawa Raj; Rasmussen, Jim; Carlsson, Georg

    2017-01-01

    Background and aimsThere is substantial evidence that legume-derived Nitrogen (N) is transferred to neighboring non-legumes in grassland mixtures. However, there is sparse information about how deep rooted non-legume forage herbs (forbs) influence N transfer in multi-species grasslands. Methodology......Red clover (Trifolium pretense L.) was grown together with perennial ryegrass (Lolium perenne L.) and one of three forb species: chicory (Cichorium intybus L.), ribwort plantain (Plantago lanceolata L.) or caraway (Carum carvi L.) in a field experiment. During the first year after the establishment, red...... clover leaves were labeled with 15N-urea to determine the N transfer from red clover to companion ryegrass and forbs. ResultsOn an annual basis, up to 15 % of red clover N was transferred to the companion ryegrass and forbs, but predominantly to the grass. The forb species did not differ in their ability...

  8. 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 composition...... and diversity on herbage yield, contents of N, neutral detergent fibre (NDF) and in vitro organic matter digestibility (IVOMD). Perennial ryegrass (PR, Lolium perenne) was sown alone and with each of four forage legumes: red clover (RC, Trifolium pratense), lucerne (LU, Medicago sativa), birdsfoot trefoil (BT......, Lotus corniculatus) and white clover (WC, Trifolium repens); WC was also sown with hybrid ryegrass (HR, Lolium × boucheanum), meadow fescue (MF, Festuca pratensis) and timothy (TI, Phleum pratense). Herbage productivity was lowest in pure PR followed by PR/BT, and highest in PR/RC; this mixture had...

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

    International Nuclear Information System (INIS)

    Entry, J.A.; Watrud, L.S.; Reeves, M.

    1999-01-01

    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 137 Cs and 90 Sr 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 137 Cs or 90 Sr 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 137 Cs and from 23.8 to 88.7% of the total amount of the 90 Sr 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 137 Cs or 90 Sr in plant tissue, % accumulation of 137 Cs or 90 Sr 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 137 Cs or 90 Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137 Cs and 90 Sr 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

  10. Tackling Contentious Invasive Plant Species: A Case Study of Buffel Grass in Australia

    Science.gov (United States)

    Grice, Anthony C.; Friedel, Margaret H.; Marshall, Nadine A.; van Klinken, Rieks D.

    2012-02-01

    Introduced plants that have both production values and negative impacts can be contentious. Generally they are either treated as weeds and their use prohibited; or unfettered exploitation is permitted and land managers must individually contend with any negative effects. Buffel grass ( Cenchrus ciliaris) is contentious in Australia and there has been no attempt to broadly and systematically address the issues surrounding it. However, recent research indicates that there is some mutual acceptance by proponents and opponents of each others' perspectives and we contend that this provides the basis for a national approach. It would require thorough and on-going consultation with stakeholders and development of realistic goals that are applicable across a range of scales and responsive to regional differences in costs, benefits and socio-economic and biophysical circumstances. It would be necessary to clearly allocate responsibilities and ascertain the most appropriate balance between legislative and non-legislative mechanisms. A national approach could involve avoiding the introduction of additional genetic material, countering proliferation in regions where the species is sparse, preventing incursion into conservation reserves where it is absent, containing strategically located populations and managing communities to prevent or reduce dominance by buffel grass. This approach could be applied to other contentious plant species.

  11. Redescriptions and reestablishments of some species belonging to the genus Prionospio (Polychaeta, Spionidae) and descriptions of three new species

    Science.gov (United States)

    Delgado-Blas, V. H.

    2014-03-01

    Available type material of Prionospio heterobranchia Moore, 1907, P. ( Prionospio) texana Hartman, 1951, P. spongicola Wesenberg-Lund, 1958 and P. ( P.) newportensis Reish, 1959, as well as newly collected material from the Southern Gulf of Mexico and Chetumal Bay in the Caribbean Sea, was examined. Several important differences were found between P. heterobranchia, P. ( Prionospio) texana, P. spongicola and P. ( P.) newportensis, and as a result, these three species are removed from synonymy with P. heterobranchia Moore, 1907, and redescribed and reinstated as valid species. In addition, three new species were identified and described: P. caribensis sp. nov., P. rosariae sp. nov. and P. jamaicensis sp. nov. A key to all species of Prionospio with five pairs of branchiae is provided.

  12. The Seed Semipermeable Layer and Its Relation to Seed Quality Assessment in Four Grass Species

    Directory of Open Access Journals (Sweden)

    Yan Y. Lv

    2017-07-01

    Full Text Available The existence of a semipermeable layer in grass seeds has been extensively reported, yet knowledge of its influence on tests for seed viability and vigor that depend upon measurement of electrical conductivity (EC is limited. This study determined the presence and location of the semipermeable layer, and its relation to seed viability and vigor assessment, in seeds of four important grass species-Elymus nutans Griseb., Lolium perenne L., Leymus chinensis (Trin. Tzvel., and Avena sativa L. Intact seeds of E. nutans, Lolium perenne, and Leymus chinensis exhibited little staining with triphenyl tetrazolium chloride (TTC, and there were no differences in EC between seeds with different germination percentage (GP (P > 0.05. After piercing the seed coat, however, all three species displayed positive staining with TTC, along with a significant negative correlation between EC and GP (E. nutans: R2 = 0.7708; Lolium perenne: R2= 0.8414; Leymus chinensis: R2 = 0.859; P < 0.01. In contrast, both intact and pierced seeds of A. sativa possessed a permeable seed coat that showed positive staining with TTC and EC values that were significantly negatively correlated with GP [R2 = 0.9071 (intact and 0.9597 (pierced; P < 0.01]. In commercial seed lots of A. sativa, a field emergence test indicated that EC showed a significant negative correlation with field emergence at two sowing dates (R2= 0.6069, P < 0.01 and 0.5316, P < 0.05. Analysis of seed coat permeability revealed the presence of a semipermeable layer located in the seed coat adjacent to the endosperm in E. nutans, Lolium perenne, and Leymus chinensis; however, no semipermeable layer was observed in A. sativa. This is the first report of the absence of a semipermeable layer in a grass species. The existence of a semipermeable layer is one of the most important factors affecting seed viability and vigor testing (based on EC measurement in E. nutans, Lolium perenne, and Leymus chinensis. Increasing the

  13. Influence of species and preservations on the quality and safety of grass silages

    Directory of Open Access Journals (Sweden)

    Jiří Skládanka

    2010-01-01

    Full Text Available The paper evaluates the quality of model silages made of wilted grass biomass and treated with silage additives. Grass species used for the production of silages were Lolium perenne, Festulolium pabulare and Festulolium braunii harvested in the first cut at the stage of earing. The assessed grass species were wilted after the cut for an identical time 36 hours (2008, resp. 24 hours (2009. The treatment was made either with a chemical preparation (formic acid, propionic acid, ammonium formate and/or with a bio­lo­gi­cal inoculant (Enterococcus faecium, Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus salivarius, cellulase, hemicellulase and amylase. The amount of the chemical ingredient was 4 l . t−1 and the amount of the biological additive was 10 g . t−1.The biomass was after wilting ensilaged in con­tai­ners whose diameter and height were 0.15 m and 0.64 m, respectively. After 60 days of ensilaging, the silages were assessed for pH, organic acids content, ethanol content and acidity of water extract (AWE; organic nutrients assessed in the silages were crude fibre (CF, neutral detergent fibre (NDF, acid detergent fibre (ADF, crude protein (CP and digestibility of organic matter (DOM. Hygienic safety was assessed from the contents of zearalenon, fumonisin and aflatoxin mycotoxins. The high (P < 0.05 dry matter (DM content in Festulolium pabulare silages indicates that the species tends to rapid wilting. The higher DM content reflected in lower biomass losses (P < 0.05. The lowest pH values (P < 0.05 were detected in silages made of Festulolium braunii. The fact relates to the higher content of lactic acid in the prepared microsilages. The use of ensiling additives affected the quality of extracts. Namely the application of the biological additive led to the increased content (P < 0.05 of not only lactic acid but acetic acid too. Titrable acidity was not affected by the ensiling additives. As to the

  14. Pathogenic Leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily

    Science.gov (United States)

    Matsunaga, James; Barocchi, Michele A.; Croda, Julio; Young, Tracy A.; Sanchez, Yolanda; Siqueira, Isadora; Bolin, Carole A.; Reis, Mitermayer G.; Riley, Lee W.; Haake, David A.; Ko, Albert I.

    2005-01-01

    Summary Proteins with bacterial immunoglobulin-like (Big) domains, such as the Yersinia pseudotuberculosis invasin and Escherichia coli intimin, are surface-expressed proteins that mediate host mammalian cell invasion or attachment. Here, we report the identification and characterization of a new family of Big domain proteins, referred to as Lig (leptospiral Ig-like) proteins, in pathogenic Leptospira. Screening of L. interrogans and L. kirschneri expression libraries with sera from leptospirosis patients identified 13 lambda phage clones that encode tandem repeats of the 90 amino acid Big domain. Two lig genes, designated ligA and ligB, and one pseudo-gene, ligC, were identified. The ligA and ligB genes encode amino-terminal lipoprotein signal peptides followed by 10 or 11 Big domain repeats and, in the case of ligB, a unique carboxy-terminal non-repeat domain. The organization of ligC is similar to that of ligB but contains mutations that disrupt the reading frame. The lig sequences are present in pathogenic but not saprophytic Leptospira species. LigA and LigB are expressed by a variety of virulent leptospiral strains. Loss of Lig protein and RNA transcript expression is correlated with the observed loss of virulence during culture attenuation of pathogenic strains. High-pressure freeze substitution followed by immunocytochemical electron microscopy confirmed that the Lig proteins were localized to the bacterial surface. Immunoblot studies with patient sera found that the Lig proteins are a major antigen recognized during the acute host infection. These observations demonstrate that the Lig proteins are a newly identified surface protein of pathogenic Leptospira, which by analogy to other bacterial immunoglobulin superfamily virulence factors, may play a role in host cell attachment and invasion during leptospiral pathogenesis. PMID:12890019

  15. Screening of Balansia epichloe-infected grass species for in situ ergot alkaloids using laser ablation electrospray ionization-mass spectrometry

    Science.gov (United States)

    The Balansia are clavicipitaceous symbiotic species associated with various species of tropical grasses. Laboratory culture procedures established that the Balansia species are often conspecific with grasses in tall fescue pastures that produced ergot alkaloids. However, any effects of hosts on the...

  16. Rhinusa Stephens: a taxonomic revision of the species belonging to the R. tetra and R. bipustulata groups (Coleoptera Curculionidae

    Directory of Open Access Journals (Sweden)

    Roberto Caldara

    2014-10-01

    Full Text Available The species of Rhinusa Stephens, 1829 (Curculionidae, Curculioninae, Mecinini belonging to the R. tetra and R. bipustulata groups are revised. Four of them from Middle East are new to science. The R. bipustulata group includes five species: R. bipustulata (Rossi, 1792; R. pelletieri sp. nov.; R. scrophulariae Caldara, 2009; R. algirica (Brisout de Barneville, 1862; R. emmrichi (Bajtenov, 1979, whereas the R. tetra group includes nine species: R. tetra (Fabricius, 1792; R. verbasci (Rosenschoeld, 1838; R. ensifer sp. nov.; R. moroderi (Reitter, 1906; R. weilli sp. nov.; R. comosa (Rosenschoeld, 1838; R. acifer sp. nov.; R asellus (Gravenhorst, 1807; R. tenuirostris (Stierlin, 1888. The following new synonym is proposed: Rhinusa bipustulata (Rossi, 1792 (= Gymnetron municipale Voss, 1960 syn. nov.. The neotype of Rhynchaenus asellus Gravenhorst, 1807 was designated. Moreover, the following lectotypes are designated: Cionus spilotus Germar, 1821; Gymnetron bipustulatum var. germari Faust, 1889; Gymnetron bodenheimeri Wagner, 1926; Gymnetron cylindrirostre Gyllenhal, 1838; Gymnetron nasutum Rosenschoeld, 1838; Gymnetron plagiatum Gyllenhal, 1838; Gymnetron polonicum Rosenschoeld, 1838; Gymnetron tenuirostre Stierlin, 1888. A key to the species, diagnoses of species groups, descriptions or redescriptions, notes on type specimens, synonymies, comparative notes, distribution, bionomics when available, photographs of habitus and drawings of rostra, terminalia and other useful characters for taxonomy are provided.

  17. A new Eastern Central Atlantic skate Raja parva sp. nov. (Rajoidei: Rajidae) belonging to the Raja miraletus species complex.

    Science.gov (United States)

    Last, Peter R; Séret, Bernard

    2016-08-05

    An investigation of combined CO1 and NADH2 data for rajid skates referable to Raja miraletus provided evidence that populations ranging from southern Africa to the North-East Atlantic and Mediterranean Sea, once considered to represent a cline, belong to a species complex consisting of at least four valid species. Raja miraletus appears to be confined to the Mediterranean Sea, and the North-East Atlantic from the Bay of Biscay south to Morocco and Madeira. The southernmost species, referable to the resurrected Raja ocellifera, occurs off southern Africa, off Namibia and from False Bay to Durban (South Africa). Two species occur off tropical West Africa, including Raja parva sp. nov. (Senegal, Liberia and Angola but is probably more widespread within the region), and another unidentified species needing further investigation. Raja cf. miraletus, confirmed from Mauritania and Senegal, appears to be a larger skate with a broader disc, more broadly pointed snout, larger spiracles, and a slightly longer and broader tail. Raja parva sp. nov. differs from nominal members of the complex in having an unusually long procaudal tail (exceeding 22% TL), as well as a combination of other external characters. Past investigators observed morphological and anatomical differences between these forms but these were thought to be due to intraspecific variability. They postulated that an upwelling at Cape Blanco (21°N) may have isolated the Mediterranean form (R. miraletus) from Mauritania-Senegal form (now known to be two species). Similarly, the Benguela Current and upwelling off Cape Frio (18°S) were thought to be responsible for separating the Angolan form (R. parva) and South African form (R. ocellifera).

  18. Coanatomical, developing and comparative analysis of 40 wood species belonging to two associations in colombian Andes highland forest

    International Nuclear Information System (INIS)

    Polanco Tapia Cesar; Grande Pulido Diana Carolina

    2009-01-01

    In this paper we conducted a relationship of the timber found with ecological aspects arising from an earlier study of the characterization, structure and floral composition practiced in the Carpatos Forest Reserve, bordering the site from which wood samples were obtained. This comparison shows a strong link between the microscopic anatomical characteristics of vegetal species with the type of association to which they belong. For example, characters such as the grouping form, the type of perforated and intervessel pits, height, number of cells wide, stratification and type of cells that make up the radio and type fiber, show a greater degree of change in the exclusive species of Ocotea callophylla-Weinmannietum pinnatae (OW) association, while the same characters show minor changes in the exclusive species of Clusia multiflorae - Weinmannietum balbisianae(CW) association. The evolution of the timber was identified through an index that suggests the research based on references like Carlquist (2001) and Leon (2001), and its relationship with the plant associations found in the study area is argued.

  19. 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

  20. The Effect of Different levels of Soil Moisture on Visual Quality, Morphological and Physiological Characteristics of Three Native Grass Species

    Directory of Open Access Journals (Sweden)

    ramin mahdavi

    2017-10-01

    Full Text Available Introduction: Over the last three decades, turfgrass breeders have put significant effort into breeding and developing turf species that have good drought resistance. As water conservation becomes an important issue, an interest is increasing in identifying grasses that require less water. Lack of water resources is most problems to increasing urban green spaces. Plants with good drought resistance are those that are able to survive stress by means of drought avoidance, drought tolerance at leaf water potentials, or both. The efficient use of water is made possible by understanding the effects of soil moisture water on crop development and yield. Drought affects the visual quality, growth rate and evapotranspiration. Researchers reported that turfgrass subjected to drought conditions for short periods could sustain a fairly good appearance by soil moisture about half of its consumptive use whenever soil moisture level falls to near permanent wilting point. Drought stress caused decrease in RWC and visual quality of many grass cultivars. In drought conditions resistance grass showed increase in proline content on their leaves. Therefore the use of native grasses with high-strength instead of imported grass with low-resistance is one way to increase landscape areas and reduce costs. The purpose of this study was to be compared native grasses with commercial grass cultivar “Super sport”. Materials and Methods: The objective of this study was to evaluate the effect of soil moisture stress levels included 85% (control, 65% and 45% of field capacity on native species Brumos tomentellus, Festuca rubra and F. arundinacea and commercial cultivars Super sport (control under greenhouse conditions. Plants were cultured in PVC containers measuring 9 cm in diameter and 60 cm deep. Soil was mixture of 70% loam soil, 20% pit mass and 10% sand. Greenhouse air temperature was maintained between 22 and 28 centigrade degree. All plants were maintained under

  1. THE PERSPECTIVE OF CULTIVATION AND UTILIZATION OF THE NEW LEGUMINOUS GRASSES SPECIES IN MOLDOVA

    Directory of Open Access Journals (Sweden)

    Alexandru TELEUŢĂ

    2015-10-01

    Full Text Available The development and modernization of our country’s agriculture is related to the revitalization of the animal breeding sector along with the implementation of new genotypes of animals and diversification of fodder production, balanced in terms of quantity and quality throughout the year, suitable for the physiological requirements of animals, and qualitative products as required in the market. Scientific research conducted in the Botanical Garden (Institute of the ASM over decades was aimed at mobilization, improvement and implementation of new non-traditional plant species that use efficiently photosynthetic active radiation and land resources to obtain fodder with a high level of vegetable protein, the fodder leguminous grasses (fam. Fabaceae Lindl. play an important role. We have studied the biological peculiarities, productivity, chemical composition and nutritional value of new fodder leguminous plant species Astragalus galegiformis, Onobrychis inermis and Medicago tianschanica of the collection of non-traditional fodder plants of the Botanical Garden (Institute of the ASM, the traditional forage crop alfalfa served as control variant. The nutritional value of fresh mass accounts: the Astragalus galegiformis - 0.27 nutritive units, 3.26 MJ metabolizable energy and 146g digestible protein/nutritive unit; Onobrychis inermis - 0.25 nutritive units, 2.56 MJ metabolizable energy and 154 g digestible protein/nutritive unit; Medicago tianschanica - 0.24 nutritive units, 2.86 MJ metabolizable energy and 173 g digestible protein/nutritive unit and alfalfa - 0.21 nutritive units, 2.28 MJ metabolizable energy and 164 g digestible protein/nutritive unit. Due to the productivity and high and stable quality of fodder, use of the plantation for a long period of time, capacity of fixing atmospheric nitrogen, the new fodder leguminous species Astragalus galegiformis, Onobrychis inermis and Medicago tianschanica can serve as initial material for enriching

  2. Interference competition as a mechanism of coexistence between two sympatric species of the grass shrimp Palaemonetes (Decapoda: Palaemonidae)

    Energy Technology Data Exchange (ETDEWEB)

    Thorp, J.H.

    1976-01-01

    Various theories have been developed to explain the puzzling coexistence of species which have broad niche overlap in critical resource utilization. The coexistence of two sympatric species of grass shrimp, Palaemonetes pugio Holthuis and p. vulgaris (Say), whose niches overlap with respect to space, food, and time, was examined in an experimental field and laboratory study. A seasonal fluctuation between sympatric and contiguous allopatric distribution of the two species of grass shrimp on natural shell, mud, and eelgrass substrata suggests that competition may be an important factor determining distribution of Palaemonetes. Field and laboratory experiments confirm that P. vulgaris can competitively displace P. pugio from the preferred shell substratum by interference competition but the tendency of grass shrimp to separate spatially in winter by bottom-depths (as in field enclosure cages) could have allowed both species to coexist on shell. Spatial separation by bottom-depth was not so evident in spring, since P. vulgaris apparently displaced P. pugio from shell to mud substratum. Occupancy of shell substratum is shown to be adaptive in that shell provides greater protection from predators than does mud. It is suggested that the spatial partitioning resulting from this interference competition promotes coexistence by reducing agonism while permitting efficient utilization of other common resources.

  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

  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. Five new species of grass cicadas in the genus Graminitigrina (Hemiptera: Cicadidae: Cicadettinae: Cicadettini) from Queensland and Northern Territory, Australia: comparative morphology, songs, behaviour and distributions.

    Science.gov (United States)

    Ewart, A; Popple, L W; Hill, K B R

    2017-02-07

    Five new species of small grass cicadas belonging to the genus Graminitigrina Ewart and Marques are described, together with detailed analyses of their calling songs. Four species occur in Queensland, G. aurora n. sp. from eastern central Queensland near Fairbairn Dam; G. flindensis n. sp. from central Queensland between Hughenden northwards for at least 108 km; G. einasleighi n. sp. from near The Lynd, Einasleigh River, northeastern Queensland; G. selwynensis n. sp. from the Selwyn Range, northwestern Queensland, at locations about 40 km east of Mount Isa and 25 km southwest of Cloncurry, this latter here transferred from G. bowensis Ewart and Marques; G. uluruensis n. sp. from Uluru and the Olgas in southwestern Northern Territory, extending northwards through Tennant Creek and apparently further north to near Larrimah, a linear distance of approximately 1190 km. These new species bring the known Graminitigrina species to ten, all superficially similar in colour and morphology. A key to male specimens is provided for the 10 species. Additional distribution records and additional aural song recordings are presented for G. bowensis, these requiring the transfer of populations previously identified as G. bowensis from Croydon and Georgetown, northern Gulf region, to G. karumbae Ewart and Marques. Detailed comparative analyses, including NMDS analyses, of the songs of all 10 species are provided, which show that the song parameters are appropriate to distinguish the species, although some partial overlap is noted in the waveform plots between the songs of G. uluruensis n. sp. and G. flindensis n. sp. Regional variations of song parameters are noted in the calling songs of most of the species described.

  6. Conceptualizing belonging.

    Science.gov (United States)

    Mahar, Alyson L; Cobigo, Virginie; Stuart, Heather

    2013-06-01

    To develop a transdisciplinary conceptualization of social belonging that could be used to guide measurement approaches aimed at evaluating the effectiveness of community-based programs for people with disabilities. We conducted a narrative, scoping review of peer reviewed English language literature published between 1990 and July 2011 using multiple databases, with "sense of belonging" as a key search term. The search engine ranked articles for relevance to the search strategy. Articles were searched in order until theoretical saturation was reached. We augmented this search strategy by reviewing reference lists of relevant papers. Theoretical saturation was reached after 40 articles; 22 of which were qualitative accounts. We identified five intersecting themes: subjectivity; groundedness to an external referent; reciprocity; dynamism and self-determination. We define a sense of belonging as a subjective feeling of value and respect derived from a reciprocal relationship to an external referent that is built on a foundation of shared experiences, beliefs or personal characteristics. These feelings of external connectedness are grounded to the context or referent group, to whom one chooses, wants and feels permission to belong. This dynamic phenomenon may be either hindered or promoted by complex interactions between environmental and personal factors.

  7. Two distinct Epichloë species symbiotic with Achnatherum inebrians, drunken horse grass.

    Science.gov (United States)

    Chen, Li; Li, Xiuzhang; Li, Chunjie; Swoboda, Ginger A; Young, Carolyn A; Sugawara, Koya; Leuchtmann, Adrian; Schardl, Christopher L

    2015-01-01

    Achnatherum inebrians, colloquially known as drunken horse grass, is associated with livestock toxicity in northern China. Epichloë gansuensis (Eg) was described from endophyte isolates from A. inebrians in Sunan County, Gansu Province, whereas a morphologically distinct variety, E. gansuensis var. inebrians (Ei), was described based on two isolates from A. inebrians seeds collected in Urumqi County, Xinjiang Province. Genome sequencing and alkaloid analyses also distinguish these taxa; the Ei isolates produce neurotropic lysergic acid amides (ergot alkaloids), and an Eg isolate produces paxilline (an indole-diterpene alkaloid). To better elucidate the taxonomic diversity of Epichloë spp. symbiotic with A. inebrians, we surveyed eight populations in Xinjiang, Gansu and Inner Mongolia provinces of China and analyzed their genotypes by multiplex PCR for alkaloid biosynthesis genes and mating-type genes. Genotypes consistent with Ei were present in all eight populations, of which they dominated seven. The Ei isolates were all mating type A and tested positive for the ergot alkaloid gene, dmaW. In contrast Eg isolates were all mating type B and had the indole-diterpene gene, idtG. The genome was sequenced from an Ei isolate from seeds collected in Xiahe County, Gansu, and compared to that of the varietal ex type isolate from Urumqi. Alkaloid genes and four different housekeeping genes were nearly identical between the two sequenced Ei isolates and were distinct from a sequenced Eg isolate. Phylogenetic analysis placed Ei, Eg and Epichloë sibirica into respective subclades of a clade that emanated from the base of the Epichloë phylogeny. Given its chemotypic, genotypic, morphological and phylogenetic distinctiveness, its widespread occurrence in rangelands of northern China, and its importance in livestock toxicity, we propose raising Ei to species rank as Epichloë inebrians. © 2015 by The Mycological Society of America.

  8. Differential belongings

    DEFF Research Database (Denmark)

    Oldrup, Helene

    2014-01-01

    This paper explores suburban middle-class residents’ narratives about housing choice, everyday life and belonging in residential areas of Greater Copenhagen, Denmark, to understand how residential processes of social differentiation are constituted. Using Savage et al.’s concepts of discursive...... and not only to the area itself. In addition, rather than seeing suburban residential areas as homogenous, greater attention should be paid to differences within such areas....

  9. New chloroplast microsatellite markers suitable for assessing genetic diversity of Lolium perenne and other related grass species.

    Science.gov (United States)

    Diekmann, Kerstin; Hodkinson, Trevor R; Barth, Susanne

    2012-11-01

    Lolium perenne (perennial ryegrass) is the most important forage grass species of temperate regions. We have previously released the chloroplast genome sequence of L. perenne 'Cashel'. Here nine chloroplast microsatellite markers are published, which were designed based on knowledge about genetically variable regions within the L. perenne chloroplast genome. These markers were successfully used for characterizing the genetic diversity in Lolium and different grass species. Chloroplast genomes of 14 Poaceae taxa were screened for mononucleotide microsatellite repeat regions and primers designed for their amplification from nine loci. The potential of these markers to assess genetic diversity was evaluated on a set of 16 Irish and 15 European L. perenne ecotypes, nine L. perenne cultivars, other Lolium taxa and other grass species. All analysed Poaceae chloroplast genomes contained more than 200 mononucleotide repeats (chloroplast simple sequence repeats, cpSSRs) of at least 7 bp in length, concentrated mainly in the large single copy region of the genome. Nucleotide composition varied considerably among subfamilies (with Pooideae biased towards poly A repeats). The nine new markers distinguish L. perenne from all non-Lolium taxa. TeaCpSSR28 was able to distinguish between all Lolium species and Lolium multiflorum due to an elongation of an A(8) mononucleotide repeat in L. multiflorum. TeaCpSSR31 detected a considerable degree of microsatellite length variation and single nucleotide polymorphism. TeaCpSSR27 revealed variation within some L. perenne accessions due to a 44-bp indel and was hence readily detected by simple agarose gel electrophoresis. Smaller insertion/deletion events or single nucleotide polymorphisms detected by these new markers could be visualized by polyacrylamide gel electrophoresis or DNA sequencing, respectively. The new markers are a valuable tool for plant breeding companies, seed testing agencies and the wider scientific community due to

  10. Ambiguous Belongings

    DEFF Research Database (Denmark)

    Pallesen, Cecil Marie

    and work in the new place and at the same time shallowly enough for them to be able to move on. Not least do they secure that ‘the crown’, which may signify ‘the culture’ or ‘Indianness’, is not buried underneath the soil. Fragarian practices allow the Indians to live transnationally while at the same time...... of ethnographic fieldwork in Moshi, Tanzania, and in London, UK, I explore and analyze intersections of local and transnational belonging, purity, citizenship strategies, networks, and claims for recognition as ‘good citizens’. Arguing that the uncertainty, which has been a fundamental condition for the Indians...

  11. The grasses (Poaceae) of the Colombian Guyana: analyses on their composition, richness, endemism, and invasion

    International Nuclear Information System (INIS)

    Giraldo Canas, Diego

    2010-01-01

    The checklist of grasses from Colombian Guyana is presented. In all, 152 species, 69 genera, and six subfamilies were recorded. Thus, in the Colombian Guyana is represented the 18.7 and 43.7% of the species and genera of Colombian grasses, respectively. The subfamilies with the highest number of species were Panicoideae (110 species/46 genera), Chloridoideae (21/9), and Bambusoideae (11/9). The most diverse genera were Paspalum (19 species), Panicum (16), Axonopus (14), Eragrostis (9), and Digitaria (8). Nineteen species are introduced and naturalized in the Colombian Guyana, which represent 12.5% of the agrostological flora for the Colombian Guyana. There were 8 endemic species (5.3% of Colombian Guayanan grasses). In addition, some species are reported for the first time for Colombian flora (belonging to Axonopus, Cyphonanthus, Gymnopogon, and Paspalum), and some species are new to science (belonging to Axonopus, Digitaria, Eragrostis, and Sacciolepis). On the other hand, some preliminary biogeographical aspect are analyzed.

  12. Sediment trapping with indigenous grass species showing differences in plant traits in northwest Ethiopia

    NARCIS (Netherlands)

    Mekonnen, Mulatie; Keesstra, Saskia D.; Ritsema, Coen J.; Stroosnijder, Leo; Baartman, Jantiene E.M.

    2016-01-01

    Soil loss from an 8% sloping Teff field in north-western Ethiopia is significant (~ 70 t ha− 1 yr− 1), and thus found to be an important source of sediment. Grass barriers showing sediment trapping efficacy (STE) are important measures in trapping sediment inside Teff fields

  13. Estimation of extractable protein in botanical fractions of legume and grass species

    DEFF Research Database (Denmark)

    Solati, Zeinab; Jørgensen, Uffe; Eriksen, Jørgen

    2018-01-01

    With a globally strong interest in bio-based products such as fuels and chemicals, a feasible source of protein for the industry with positive economic impacts could be from leaves. However, more knowledge is needed on how to improve the content of extractable protein. Grasses and legumes have a ...

  14. Study on the mineral extraction of legume and grass species from various soil types, by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Piasentin, R.M.; Armelin, M.J.A.; Cruvinel, P.E.

    1998-01-01

    Instrumental neutron activation analysis (INAA), followed by gamma-ray spectrometry, was used to determine the concentration of K, Ca, Mg, Na, Zn, Fe, Mn, Mo, Co, Cr, La, Eu and Th in six species of legumes and three species of grasses. Each species of forage was cultivated on two different oxisols, that is, a red yellow Latossol and a dark red Latossol, with the aim of comparing the influence of the soils in the mineral extraction. Besides, on each kind of soil, two different limestone concentrations were used in order to verify how the soil pH correction could influence the elemental absorption in each species, and at the same time; to search for an optimum value of limestone concentration for each soil. (author)

  15. 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.

  16. 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.

  17. Ecological niche differentiation of polyploidization is not supported by environmental differences among species in a cosmopolitan grass genus.

    Science.gov (United States)

    Visser, Vernon; Molofsky, Jane

    2015-01-01

    • Polyploidization frequently results in the creation of new plant species, the establishment of which is thought to often be facilitated by ecological niche differentiation from the diploid species. We tested this hypothesis using the cosmopolitan grass genus Phalaris (Poaceae), consisting of 19 species that range from diploid to tetraploid to hexaploid. Specifically, we tested whether (1) polyploids occupy more extreme environments and/or (2) have broader niche breadths and/or (3) whether the polyploid species' distributions indicate a niche shift from diploid species.• We employed a bootstrapping approach using distribution data for each species and eight environmental variables to investigate differences between species in the means, extremes, and breadths of each environmental variable. We used a kernel smoothing technique to quantify niche overlap between species.• Although we found some support for the three hypotheses for a few diploid-polyploid pairs and for specific environmental variables, none of these hypotheses were generally supported.• Our results suggest that these commonly held hypotheses about the effects of polyploidization on ecological distributions are not universally applicable. Correlative biogeographic studies like ours provide a necessary first step for suggesting specific hypotheses that require experimental verification. A combination of genetic, physiological, and ecological studies will be required to achieve a better understanding of the role of polyploidization in niche evolution. © 2015 Botanical Society of America, Inc.

  18. Grass and forb species for revegetation of mixed soil-lignite overburden in East Central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Skousen, J.G.; Call, C.A. (West Virginia University, Morgantown, WV (USA). Division of Plant and Soil Sciences)

    Ten grasses and seven forbs were seeded into mixed soil-lignite overburden in the Post Oak Savannah region of Texas and monitored for establishment and growth over a 3-year period without fertilization. Buffelgrass (Cenchrus ciliaris), green sprangletop (Leptochloa dubia), switchgrass (Panicum virgatum), and kleingrass (P. coloratum) developed monotypic stands with sufficent density, aerial cover, and aboveground biomass to stabilize the mixed soil-lignite overburden surface by the end of the first growing season. Plant mortality eliminated buffelgrass and green sprangletop stands by the end of the third growing season. Indiangrass (Sorghastrum nutans) developed a satisfactory stand by the end of the third growing season, while Oldworld bluestem (Bothriochloa X Dicanthium), yellow bluestem (Bothriochloa ischaemum), and sideoats grama (Bouteloua curtipendula) established at a slower rate. Cover and biomass measurements from an adjacent, unfertilized stand of Coastal bermudagrass (Cynodon dactylon) were compared with those of seeded grasses throughout the study. Partidge pea (Cassia fasciculata) established rapidly and had the greatest cover and biomass of all seeded forbs by the end of the first growing season. Sericea lespedeza (Lespedeza cuneata), Illinois bundleflower (Desmanthus illinoensis), and western indigo (Indigofera miniata) developed adequate stands for surface stabilization by the end of the third growing season, while faseanil indigo (Indigofera suffruticosa), virgata lespedeza (Lespedeza virgata), and awnless bushsunflower (Simsia calva) showed slower establishment. 27 refs., 3 tabs.

  19. The species of Aplysia belonging to the subgenus Tullia Pruvot-Fol, 1933: On a generic character in statu nascendi

    NARCIS (Netherlands)

    Engel, H.; Eales, Nellie B.

    1957-01-01

    Mme PRUVOT-FOL, 1933, p. 400, established the subgenus Tullia for Aplysia juliana QUOY et GAIMARD, and 1934, p. 41 added other species of Aplysia with a distinct sucking disk at the end of the foot. Living animals have been figured and their variation has been described by BABA 1937a, p. 211, and

  20. 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.

  1. Postembryonic development of hard jaws (trophi) in a species belonging to the Brachionus plicatilis complex (Rotifera, Monogononta): a morphometric analysis.

    Science.gov (United States)

    Fontaneto, Diego; Melone, Giulio

    2006-04-01

    The presence of hard jaws (trophi), with species-specific shape and size, is a taxonomic feature of Rotifera, a group of microscopic metazoans. Since trophi are used to discriminate among species, it is important to know whether these structures change in taxonomically important ways during postembryonic development. Using both SEM and optical images, we analyzed more than 100 individuals of a single clonal lineage of a monogonont rotifer, Brachionus plicatilis, in order to describe body and trophi development after hatching. Body size, expressed as lorica width and length, was isometrically related to age of the animals only during preadult stages. Trophi size, expressed as length of the different parts, was unrelated to either age or body size. Therefore, trophi elements do not grow after hatching in B. plicatilis. Despite the dimensional invariance with age, some differences in trophi size among individuals of the same clone were recorded. No difference in left-right asymmetry of the trophi was shown; the asymmetric elements of the trophi named rami consistently had the right ramus longer than the left. This constancy is in contrast to the reported trophi asymmetries in bdelloid rotifers, in which left-right asymmetries are not constant within clonal lineages. In conclusion, we suggest that also trophi size, constant within the analyzed clone, may be used as an additional taxonomic feature to help in the discrimination of taxa within the B. plicatilis complex of cryptic species. Copyright (c) 2006 Wiley-Liss, Inc.

  2. Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S. D.

    1998-12-01

    Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

  3. 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.

  4. Loss of native herbaceous species due to woody plant encroachment facilitates the establishment of an invasive grass.

    Science.gov (United States)

    Alofs, Karen M; Fowler, Norma L

    2013-03-01

    Although negative relationships between diversity (frequently measured as species richness) and invasibility at neighborhood or community scales have often been reported, realistic natural diversity gradients have rarely been studied at this scale. We recreated a naturally occurring gradient in species richness to test the effects of species richness on community invasibility. In central Texas savannas, as the proportion of woody plants increases (a process known as woody plant encroachment), herbaceous habitat is both lost and fragmented, and native herbaceous species richness declines. We examined the effects of these species losses on invasibility in situ by removing species that occur less frequently in herbaceous patches as woody plant encroachment advances. This realistic species removal was accompanied by a parallel and equivalent removal of biomass with no changes in species richness. Over two springs, the nonnative bunchgrass Bothriochloa ischaemum germinated significantly more often in the biomass-removal treatment than in unmanipulated control plots, suggesting an effect of native plant density independent of diversity. Additionally, significantly more germination occurred in the species-removal treatment than in the biomass-removal treatment. Changes in species richness had a stronger effect on B. ischaemum germination than changes in plant density, demonstrating that niche-related processes contributed more to biotic resistance in this system than did species-neutral competitive interactions. Similar treatment effects were found on transplant growth. Thus we show that woody plant encroachment indirectly facilitates the establishment of an invasive grass by reducing native diversity. Although we found a negative relationship between species richness and invasibility at the scale of plots with similar composition and environmental conditions, we found a positive relationship between species richness and invasibility at larger scales. This apparent

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

    Science.gov (United States)

    Ehlers, Bodil K

    2011-01-01

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

    Directory of Open Access Journals (Sweden)

    Bodil K Ehlers

    Full Text Available 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.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.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.

  7. Soil Microorganisms Alleviate the Allelochemical Effects of a Thyme Monoterpene on the Performance of an Associated Grass Species

    Science.gov (United States)

    Ehlers, Bodil K.

    2011-01-01

    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. PMID:22125596

  8. Metabolite fingerprinting, pathway analyses, and bioactivity correlations for plant species belonging to the Cornaceae, Fabaceae, and Rosaceae families.

    Science.gov (United States)

    Son, Su Young; Kim, Na Kyung; Lee, Sunmin; Singh, Digar; Kim, Ga Ryun; Lee, Jong Seok; Yang, Hee-Sun; Yeo, Joohong; Lee, Sarah; Lee, Choong Hwan

    2016-09-01

    A multi-parallel approach gauging the mass spectrometry-based metabolite fingerprinting coupled with bioactivity and pathway evaluations could serve as an efficacious tool for inferring plant taxonomic orders. Thirty-four species from three plant families, namely Cornaceae (7), Fabaceae (9), and Rosaceae (18) were subjected to metabolite profiling using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and ultrahigh performance liquid chromatography-linear trap quadrupole-ion trap-mass spectrometry (UHPLC-LTQ-IT-MS/MS), followed by multivariate analyses to determine the metabolites characteristic of these families. The partial least squares discriminant analysis (PLS-DA) revealed the distinct clustering pattern of metabolites for each family. The pathway analysis further highlighted the relatively higher proportions of flavonols and ellagitannins in the Cornaceae family than in the other two families. Higher levels of phenolic acids and flavan-3-ols were observed among species from the Rosaceae family, while amino acids, flavones, and isoflavones were more abundant among the Fabaceae family members. The antioxidant activities of plant extracts were measured using ABTS, DPPH, and FRAP assays, and indicated that extracts from the Rosaceae family had the highest activity, followed by those from Cornaceae and Fabaceae. The correlation map analysis positively links the proportional concentration of metabolites with their relative antioxidant activities, particularly in Cornaceae and Rosaceae. This work highlights the pre-eminence of the multi-parallel approach involving metabolite profiling and bioactivity evaluations coupled with metabolic pathways as an efficient methodology for the evaluation of plant phylogenies.

  9. In vitro antifungal activity against Candida species of Sri Lankan orthodox black tea (Camellia sinensis L. belonging to different agro-climatic elevations

    Directory of Open Access Journals (Sweden)

    Wanigasekara Daya Ratnasooriya

    2017-02-01

    Full Text Available Objective: To investigate the antifungal potential of different grades of Sri Lankan orthodox black tea [orange pekoe, broken orange pekoe fannings (BOPF and Dust No. 1] belonging to the three agro-climatic elevations (low, mid and high. Methods: Antifungal activity was assessed in vitro using methanolic extracts (300 µg/disc and agar disc diffusion bioassay technique against three Candida species, Candida albicans (C. albicans, Candida glabrata (C. glabrata, and Candida tropicalis. ketoconazole and itraconazole mixture was used as positive control (10 µg/disc and methanol was used as the negative control. The minimum inhibitory concentrations were also determined using standard protocols. Results: None of the extracts were effective against Candida tropicalis. Furthermore, orange pekoe grade tea belonging to all agro-climatic elevations did not induce any antifungal activity against C. albicans and C. glabrata as well. Conversely, Dust No. 1 belonging to all three agro-climatic elevations and low-grown BOPF showed moderate antifungal activity against C. albicans and C. glabrata. Interestingly, the severity of the antifungal effect varied with agroclimatic elevations. The minimum inhibitory concentrations ranged from 64.00–128.00 µg/mL against C. glabrata and 128.00-256.00 µg/mL against C. albicans. Conclusions: Sri Lankan Dust No. 1 and BOPF have marked antifungal activity in vitro and offer promise to be used as a supplementary beverage in prophylaxis and during drug treatment in candidiasis.

  10. Anaerobic mono-digestion of lucerne, grass and forbs – Influence of species and cutting frequency

    DEFF Research Database (Denmark)

    Wahid, Radziah; Feng, Lu; Cong, Wenfeng

    2018-01-01

    but it was not possible to ascertain whether this was due to organic overload alone or if high ammonia levels during Lu-4 digestion were contributing to the reduced performance. It was found that four cuts per year was suitable for a lab-scale mono-digestion system as the substrate was less fibrous and has lower dry......In the present study, biogas potentials of multispecies swards including grass, lucerne, caraway, ribwort plantain and chicory from two- and four-cut regimes (Mix-2 and Mix-4) for mono-digestion applying batch and continuous modes under lab-scale conditions were investigated. The gas yields...... confirmed with continuous experiments, during which the reactor digesting Mix-4 was stable throughout the experiment with low ammonia and volatile fatty acid (VFA) concentration. Meanwhile, mono-digestion of Lu-4 led to elevated VFA levels, even at a comparatively low organic loading rate of 1.76 g L−1 d−1...

  11. Coping with low nutrient availability and inundation: root growth responses of three halophytic grass species from different elevations along a flooding gradient

    NARCIS (Netherlands)

    Bouma, T.J.; Koutstaal, B.P.; Van Dongen, M.; Nielsen, K.F.

    2001-01-01

    We describe the responses of three halophytic grass species that dominate the low (Spartina anglica), middle (Puccinellia maritima) and high (Elymus pycnanthus) parts of a salt marsh, to soil conditions that are believed to favour contrasting root-growth strategies. Our hypotheses were: (1)

  12. Flavonoid concentrations in three grass species and a sedge grown in the field and under controlled environment conditions in response to enhanced UV-B radiation.

    NARCIS (Netherlands)

    van de Staaij, J.W.M.; Bakker, N.; Oosthoek, A.; Broekman, R.A.; van Beem, A.P.; Stroetenga, M.J.; Aerts, R.; Rozema, J.

    2002-01-01

    An investigation was carried out to find whether enhanced levels of UV-B radiation induce increased concentrations of flavonoids in the leaves of the grass species Deschampsia antarctica, Deschampsia borealis and Calamagrostis epigeios and the sedge Carex arenaria. Whether the enhanced levels of

  13. Revision of fleas of the genus Plocopsylla belonging to the 'angusticeps-lewisi' complex in the Andean biogeographic region, with the description of a new species.

    Science.gov (United States)

    Sanchez, J; Beaucournu, J-C; Lareschi, M

    2015-06-01

    In Argentina, the Andean biogeographic region accommodates the most diverse population of fleas in the country. The Craneopsyllinae (Siphonaptera: Stephanocircidae) represent one of the most commonly found subfamilies in this region and show some endemism and high diversity. Plocopsylla is the most diverse genus of Craneopsyllinae; it includes 10 species mainly distributed in the Patagonian subregion, which parasitize sigmodontine rodents (Rodentia: Cricetidae). We describe and illustrate the morphology of the aedeagus in species of Plocopsylla that belong to the 'angusticeps-lewisi' complex. This character is of diagnostic value in differentiating among species. A new species of this complex, Plocopsylla (Plocopsylla) linardii sp. n., is described and identified by the shape and chaetotaxy of the distal arm of sternite IX, as well as by the shape of the median dorsal lobe of the aedeagus. New host associations for this complex and range extensions for most of its species are reported. Plocopsylla (P.) silewi is recorded for the first time in Argentina. The southern limits of the distributions of Plocopsylla (P.) lewisi and Plocopsylla (P.) wilesi are extended to Santa Cruz Province. The angusticeps-lewisi complex is found for the first time in San Juan Province. The information may be useful in epidemiological studies of flea-borne diseases. © 2015 The Royal Entomological Society.

  14. 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.

  15. Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant

    International Nuclear Information System (INIS)

    Khan, Sumaira; Kazi, Tasneem Gul; Kolachi, Nida Fatima; Baig, Jameel Ahmed; Afridi, Hassan Imran; Shah, Abdul Qadir; Kumar, Sham; Shah, Faheem

    2011-01-01

    The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V 5+ species from soil, vegetable and grass samples using Na 2 CO 3 in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V 5+ and V 4+ determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 μg/g in test and control soil samples, respectively. The contents of V 5+ and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 μg/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P 5+ and V 4+ species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

  16. Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sumaira, E-mail: skhanzai@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kolachi, Nida Fatima, E-mail: nidafatima6@gmail.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Shah, Abdul Qadir, E-mail: aqshah07@yahoo.com [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kumar, Sham; Shah, Faheem [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-06-15

    The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V{sup 5+} species from soil, vegetable and grass samples using Na{sub 2}CO{sub 3} in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V{sup 5+} and V{sup 4+} determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 {mu}g/g in test and control soil samples, respectively. The contents of V{sup 5+} and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 {mu}g/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P < 0.01). Statistical evaluations indicate that the sum of concentrations of V{sup 5+} and V{sup 4+} species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

  17. Competition between two grass species with and without grazing over a productivity gradient

    NARCIS (Netherlands)

    Kuijper, D.P.J.; Dubbeld, J.; Bakker, J.P.

    2005-01-01

    Soil nutrient-level and herbivory are predicted to have opposing effects on the allocation pattern of the competitive dominant plant species. Lower stem and higher leaf allocation are favoured when plants are grazed, whereas a higher stem allocation is favoured at high nutrient levels. Grazing by

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

    OpenAIRE

    Halina Lipińska

    2012-01-01

    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 perfo...

  19. Tubulin-isotype analysis of two grass species-resistant to dinitroaniline herbicides.

    Science.gov (United States)

    Waldin, T R; Ellis, J R; Hussey, P J

    1992-09-01

    Trifluralin-resistant biotypes of Eleusine indica (L.) Gaertn. (goosegrass) and Setaria viridis (L.) Beauv. (green foxtail) exhibit cross-resistance to other dinitroaniline herbicides. Since microtubules are considered the primary target site for dinitroaniline herbicides we investigated whether the differential sensitivity of resistant and susceptible biotypes of these species results from modified tubulin polypeptides. One-dimensional and two-dimensional polyacrylamide gel electrophoresis combined with immunoblotting using well-characterised anti-tubulin monoclonal antibodies were used to display the family of tubulin isotypes in each species. Seedlings of E. indica exhibited four β-tubulin isotypes and one α-tubulin isotype, whereas those of S. viridis exhibited two β-tubulin and two α-tubulin isotypes. Comparison of the susceptible and resistant biotypes within each species revealed no differences in electrophoretic properties of the multiple tubulin isotypes. These results provide no evidence that resistance to dinitroaniline herbicides is associated with a modified tubulin polypeptide in these biotypes of E. indica or S. viridis.

  20. Two new genera and five new species of Mugadina-like small grass cicadas (Hemiptera: Cicadidae: Cicadettini) from Central and Eastern Australia: comparative morphology, songs, behaviour and distributions.

    Science.gov (United States)

    Ewart, A

    2018-04-20

    Moulds (2012) established the genus Mugadina for two small cicadas, M. marshalli (Distant) and M. emma (Goding and Froggatt), both grass inhabiting species known from Queensland and New South Wales. Both species are notable for their relatively simple 'ticking' songs. Moulds further noted that there were at least two superficially similar genera of cicadas, but each with different genitalia. This paper describes two new genera of small (9-15 mm body lengths) and distinctive grass cicadas with genitalia that are very similar to those of Mugadina, but possess clear morphological, colour and calling song differences. The new genera are: Heremusina n. gen. with two known species namely H. udeoecetes n. sp. and H. pipatio n. sp.; the second new genus is Xeropsalta n. gen., containing four known species, X. thomsoni n. sp., X. aridula n. sp., X. rattrayi n. sp., and X. festiva n. comb. Heremusina n. gen. species are described from the Alice Springs area of Northern Territory and the Cloncurry area of northwest Queensland, from arid to semi arid habitats. The Xeropsalta n. gen. species are described from western, southwest and central Queensland, and from the Simpson and Strzelecki Deserts in northeastern South Australia and northwestern New South Wales, respectively, all locations in very arid to arid habitats, but close to seasonal (often irregular) rivers and lakes. X. festiva n. comb. occurs in semi arid habitats in southern and southeastern Australia.        Detailed taxonomic descriptions are provided of the new species, together with distributions, habitats, and the calling songs. The Heremusina species emit songs with short repetitive buzzing echemes, the echeme durations differing between each species. The Xeropsalta songs are notable for their complexity, containing multiple elements with rapid changes of amplitudes and temporal structures, rather atypical of the songs of most small grass dwelling cicadas. Detailed song structures distinguishing each of

  1. Grass is not always greener: Rodenticide exposure of a threatened species near marijuana growing operations

    Science.gov (United States)

    Franklin, Alan B.; Carlson, Peter C.; Rex, Angela; Rockweit, Jeremy T.; Garza, David; Culhane, Emily; Volker, Steven F; Dusek, Robert J.; Shearn-Bochsler, Valerie I.; Gabriel, Mourad W.; Horak, Katherine E.

    2018-01-01

    ObjectiveMarijuana (Cannabis spp.) growing operations (MGO) in California have increased substantially since the mid-1990s. One environmental side-effect of MGOs is the extensive use of anticoagulant rodenticides (AR) to prevent damage to marijuana plants caused by wild rodents. In association with a long-term demographic study, we report on an observation of brodifacoum AR exposure in a threatened species, the northern spotted owl (Strix occidentalis caurina), found freshly dead within 669–1347 m of at least seven active MGOs.ResultsLiver and blood samples from the dead northern spotted owl were tested for 12 rodenticides. Brodifacoum was the only rodenticide detected in the liver (33.3–36.3 ng/g) and blood (0.48–0.54 ng/ml). Based on necropsy results, it was unclear what role brodifacoum had in the death of this bird. However, fatal AR poisoning has been previously reported in owls with relatively low levels of brodifacoum residues in the liver. One likely mechanism of AR transmission from MGOs to northern spotted owls in California is through ingestion of AR contaminated prey that frequent MGOs. The proliferation of MGOs with their use of ARs in forested landscapes used by northern spotted owls may pose an additional stressor for this threatened species.

  2. A comparison of stable caesium uptake by six grass species of contrasting growth strategy

    International Nuclear Information System (INIS)

    Willey, N.J.; Martin, M.H.

    1997-01-01

    Six plants in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mM, 0.15 mM, 0.3 mM, 1.0 mM and 3.0 mM concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil. (author)

  3. Grass survey of the Itremo Massif records endemic central highland ...

    African Journals Online (AJOL)

    Twenty species are endemic to the central highlands, and a further 1 4 species are restricted to Madagascar. Five ecological groups of grasses were identified in the Itremo Massif: shade species in gallery forests, open wet area species, fire grasses, anthropogenic disturbance associated grasses and rock-dwelling grasses.

  4. 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

    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...... found high N2-fixation of more than 300 kg N ha-1 from both red clover and alfalfa even when the two mixtures received 300 kg total-N ha-1 in cattle slurry. The addition of cattle slurry N fertilizer lowered N2-fixation for white clover and red clover as expected, but for bird's-foot trefoil and alfalfa...... no changes in the proportion of N derived from N2-fixation was observed. We conclude that the competition for available soil N from perennial ryegrass in mixture was an important factor for the proportion of N in alfalfa, white clover, and bird's-foot trefoil obtained from N2-fixation. White clover had...

  5. Comparative nutritional ecology of grass-feeding in a sub-Antarctic beetle: the impact of introduced species on Hydromedion sparsutum from South Georgia.

    Science.gov (United States)

    Chown, S L; Block, W

    1997-07-01

    South Georgia has many introduced plant and animal species, a consequence of its long history of human habitation. Introduced reindeer have a strong effect on the vegetation of the Stromness Bay area by causing the replacement of indigenous species by grazing-tolerant grasses such as the exotic Poa annua, and in certain circumstances, the indigenous Festuca contracta. Recently it has been argued that an introduced predatory carabid has contributed to declines in the abundance and an increase in the body size of adults of the indigenous perimylopid beetle Hydromedion sparsutum. However, it also appears that body size of these beetles is smaller in areas where exotic grasses predominate compared to undisturbed areas. Here we test the hypothesis that by causing the spread of poorer quality grasses, especially the exotic Poa annua, reindeer may be having an indirect effect on H. sparsutum. To do this we examined the nutritional ecology of H. sparsutum larvae on four grass species which form a major part of its diet, viz. the indigenous Parodiochloa flabellata, Phleum alpinum and Festuca contracta, and the exotic Poa annua. Larvae showed the highest growth rate on Parodiochloa flabellata, followed by Phleum alpinum, F. contracta and Poa annua. These differences are due to poorer absorption of the exotic grass, and poorer utilization of the absorbed material in the case of F. contracta. Poor growth of larvae on F. contracta appears to be due to its low water and nitrogen contents, whereas in the case of P. annua a combination of low water content and high nitrogen content may be responsible for low growth rates. Low growth rates associated with poor-quality food may lead either to a prolongation of the life cycle or of the length of feeding bouts of an insect. Neither option appears to be feasible for H. sparsutum, and this means that the outcome of feeding on poorer-quality foods would be a reduction in final adult size. This has fitness consequences for the beetle

  6. A molecular identification system for grasses: a novel technology for forensic botany.

    Science.gov (United States)

    Ward, J; Peakall, R; Gilmore, S R; Robertson, J

    2005-09-10

    Our present inability to rapidly, accurately and cost-effectively identify trace botanical evidence remains the major impediment to the routine application of forensic botany. Grasses are amongst the most likely plant species encountered as forensic trace evidence and have the potential to provide links between crime scenes and individuals or other vital crime scene information. We are designing a molecular DNA-based identification system for grasses consisting of several PCR assays that, like a traditional morphological taxonomic key, provide criteria that progressively identify an unknown grass sample to a given taxonomic rank. In a prior study of DNA sequences across 20 phylogenetically representative grass species, we identified a series of potentially informative indels in the grass mitochondrial genome. In this study we designed and tested five PCR assays spanning these indels and assessed the feasibility of these assays to aid identification of unknown grass samples. We confirmed that for our control set of 20 samples, on which the design of the PCR assays was based, the five primer combinations produced the expected results. Using these PCR assays in a 'blind test', we were able to identify 25 unknown grass samples with some restrictions. Species belonging to genera represented in our control set were all correctly identified to genus with one exception. Similarly, genera belonging to tribes in the control set were correctly identified to the tribal level. Finally, for those samples for which neither the tribal or genus specific PCR assays were designed, we could confidently exclude these samples from belonging to certain tribes and genera. The results confirmed the utility of the PCR assays and the feasibility of developing a robust full-scale usable grass identification system for forensic purposes.

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

    Science.gov (United States)

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

  8. The effect of hydraulic lift on organic matter decomposition, soil nitrogen cycling, and nitrogen acquisition by a grass species.

    Science.gov (United States)

    Armas, Cristina; Kim, John H; Bleby, Timothy M; Jackson, Robert B

    2012-01-01

    Hydraulic lift (HL) is the passive movement of water through plant roots, driven by gradients in water potential. The greater soil-water availability resulting from HL may in principle lead to higher plant nutrient uptake, but the evidence for this hypothesis is not universally supported by current experiments. We grew a grass species common in North America in two-layer pots with three treatments: (1) the lower layer watered, the upper one unwatered (HL), (2) both layers watered (W), and (3) the lower layer watered, the upper one unwatered, but with continuous light 24 h a day to limit HL (no-HL). We inserted ingrowth cores filled with enriched-nitrogen organic matter ((15)N-OM) in the upper layer and tested whether decomposition, mineralization and uptake of (15)N were higher in plants performing HL than in plants without HL. Soils in the upper layer were significantly wetter in the HL treatment than in the no-HL treatment. Decomposition rates were similar in the W and HL treatments and lower in no-HL. On average, the concentration of NH(4)(+)-N in ingrowth cores was highest in the W treatment, and NO(3)(-)-N concentrations were highest in the no-HL treatment, with HL having intermediate values for both, suggesting differential mineralization of organic N among treatments. Aboveground biomass, leaf (15)N contents and the (15)N uptake in aboveground tissues were higher in W and HL than in no-HL, indicating higher nutrient uptake and improved N status of plants performing HL. However, there were no differences in total root nitrogen content or (15)N uptake by roots, indicating that HL affected plant allocation of acquired N to photosynthetic tissues. Our evidence for the role of HL in organic matter decomposition and nutrient cycling suggests that HL could have positive effects on plant nutrient dynamics and nutrient turnover.

  9. Neglected grass species of Southern Africa: Nutritive value of conserved Hyperthelia dissoluta harvested at different growth stages

    Directory of Open Access Journals (Sweden)

    Jacob Gusha

    2016-09-01

    Full Text Available Native species like Hyperthelia dissoluta have great potential in livestock production but not much has been done to improve their contribution to that sector.  This study examined 2 conservation methods (drying and ensiling and 3 different growth stages, namely: elongation stage (January, early flowering (February and late flowering stage (March of H. dissoluta in terms of nutritional composition and digestibility.  The method of conservation had a significant effect (P<0.05 on nutritive value, with silage having more P and CP than hay.  Stage of growth had an effect (P<0.05 on all nutritional properties of both hay and silage:  Phosphorus, Ca and CP concentrations and digestibility of hay and silage decreased with maturity, while NDF and ADF concentrations increased.  Silage pH value was significantly higher at elongation (5.2 and late flowering growth stages (5.7 than at early flowering (4.4.  Dry matter digestibility of the conserved material reached levels as high as 82% for silage made at the elongation stage with all values at least 60%.  We conclude that H. dissoluta can be conserved as both silage and hay to produce a good quality feed.  Harvesting at the early flowering stage would seem to provide a good compromise between quantity (not measured in this study and quality of harvested forage.  Further studies seem warranted to determine the acceptability and intake of the material by livestock, the advantages of adding fermentable carbohydrates during ensiling and DM yields in different areas and a range of seasonal conditions. Keywords: Air drying, hay, perennial native grasses, plastic bag silo, quality silage.DOI: 10.17138/TGFT(4179-184

  10. 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...

  11. Transfer factors of 226Ra, 210Pb and 210Po from NORM-contaminated oil field soil to some Atriplex species, Alfalfa and Bermuda grass

    International Nuclear Information System (INIS)

    Al-Masria, M.S.; Mukalallati, H.; Al-Hamwi, A.

    2014-01-01

    Transfer factors of 226 Ra, 210 Pb and 210 Po from soil contaminated with naturally occurring radioactive materials (NORM) in oil fields to some grazing plants were determined using pot experiments. Contaminated soil was collected from a dry surface evaporation pit from a Syrian oil field in the Der Ezzor area. Five types of plants (Atriplex halimus L., Atriplex canescens, Atriplex Leucoclada Bioss, Alfalfa and Bermuda grass) were grown and harvested three times over two years. The results show that the mean transfer factors of 226 Ra from the contaminated soil to the studied plant species were 1.6 x 10 -3 for Atriplex halimus L., 2.1 x 10 -3 for Atriplex canescens, 2.5 x 10 -3 for Atriplex Leucoclada Bioss, 8.2 x 10 -3 for Bermuda grass, and the highest value was 1.7 x 10 -2 for Alfalfa. Transfer factors of 210 Pb and 210 Po were higher than 226 Ra TFs by one order of magnitude and reached 7 x 10 -3 , 1.1 x 10 -2 , 1.2 x 10 -2 , 3.2 x 10 -2 and 2.5 x 10 -2 for Atriplex halimus, Atriplex canescens, Atriplex Leucoclada Bioss, Bermuda grass and Alfalfa, respectively. The results can be considered as base values for transfer factors of 226 Ra, 210 Pb and 210 Po in semiarid regions. (authors)

  12. 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.

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

    International Nuclear Information System (INIS)

    Deram, Annabelle; Denayer, Franck-Olivier; Petit, Daniel; Van Haluwyn, Chantal

    2006-01-01

    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

  14. 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.

  15. Photosynthetic pathways and the geographical distribution of grasses in South West Africa/Namibia

    International Nuclear Information System (INIS)

    Ellis, R.P.; Vogel, J.C.; Fuls, A.

    1980-01-01

    Analysis of floristic lists for South West Africa/Namibia shows that, throughout the territory, more than 95% of the grass species occurring in any given area display the C 4 photosynthetic pathway. Exceptions are areas in the north-east and southwest where between 5% and 18% of the grass species are of the C 3 type. The south-western district of Luderitz falls within the winter rainfall area and it is only here that temperate C 3 genera are found. The C 3 species in the north-east belong to tropical groups. Most of the South West African C 3 grasses grow in specialized habitats and are either hydrophytes or sciophytes. Subdivision of the C 4 grasses into the three subtypes of the C 4 pathway reveals distinctive distributional trends. Malate formers or NADP-me species clearly become more abundant with increasing rainfall, whereas the aspartate formers show the opposite tendency. However, within the aspartate forming group the results show that it is specifically the NAD-me type of species which dominate in areas of very low precipitation, notably in the Namib and pre-Namib areas where rainfall is less than 200 mm/yr. The PEP-ck species form a group intermediate between the malate formers and the NAD-me grasses, especially as far as their water requirements are concerned [af

  16. Photosynthetic pathways and the geographical distribution of grasses in South West Africa/Namibia

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, R P [Department of Agriculture and Fisheries, Pretoria (South Africa). Botanical Research Institute; Vogel, J C; Fuls, A [Council for Scientific and Industrial Research, Pretoria (South Africa). National Physical Research Lab.

    1980-07-01

    Analysis of floristic lists for South West Africa/Namibia shows that, throughout the territory, more than 95% of the grass species occurring in any given area display the C/sub 4/ photosynthetic pathway. Exceptions are areas in the north-east and southwest where between 5% and 18% of the grass species are of the C/sub 3/ type. The south-western district of Luderitz falls within the winter rainfall area and it is only here that temperate C/sub 3/ genera are found. The C/sub 3/ species in the north-east belong to tropical groups. Most of the South West African C/sub 3/ grasses grow in specialized habitats and are either hydrophytes or sciophytes. Subdivision of the C/sub 4/ grasses into the three subtypes of the C/sub 4/ pathway reveals distinctive distributional trends. Malate formers or NADP-me species clearly become more abundant with increasing rainfall, whereas the aspartate formers show the opposite tendency. However, within the aspartate forming group the results show that it is specifically the NAD-me type of species which dominate in areas of very low precipitation, notably in the Namib and pre-Namib areas where rainfall is less than 200 mm/yr. The PEP-ck species form a group intermediate between the malate formers and the NAD-me grasses, especially as far as their water requirements are concerned.

  17. Relevance of Allergenic Sensitization to Cynodon dactylon and Phragmites communis: Cross-reactivity With Pooideae Grasses.

    Science.gov (United States)

    López-Matas, M A; Moya, R; Cardona, V; Valero, A; Gaig, P; Malet, A; Viñas, M; García-Moral, A; Labrador, M; Alcoceba, E; Ibero, M; Carnés, J

    The homologous group of sweet grasses belongs to the Pooideae subfamily, but grass pollen species from other subfamilies can also cause allergy, such as Cynodon dactylon (Chloridoideae) and Phragmites communis (Arundinoideae). C dactylon and P communis have not been included in the sweet grasses homologous group because of their low cross-reactivity with other grasses. The aims of this study were to investigate the profile of sensitization to C dactylon and P communis in patients sensitized to grasses and to analyze cross-reactivity between these 2 species and temperate grasses. Patients were skin prick tested with a grass mixture (GM). Specific IgE to GM, C dactylon, P communis, Cyn d 1, and Phl p 1 was measured by ImmunoCAP. A pool of sera was used for the immunoblot assays. Cross-reactivity was studied by ELISA and immunoblot inhibition. Thirty patients had sIgE to GM. Twenty-four (80%) had positive results for C dactylon, 27 (90%) for P communis, 22 (73.3%) for nCyn d 1, and 92.9% for rPhl p 1. Bands were detected in the 3 extracts by immunoblot. Inhibition of GM was not observed with C dactylon or P communis by immunoblot or ELISA inhibition. When C dactylon or P communis were used in the solid phase, GM produced almost complete inhibition. Eighty percent of patients sensitized to grasses were also sensitized to C dactylon and 90% were sensitized to P communis. Sensitization to these species seems to be induced by allergens different to those in sweet grasses.

  18. The grasses (Poaceae) of the Colombian guayana: analyses on their composition, richness, endemism, and invasion

    International Nuclear Information System (INIS)

    Canas, Diego Giraldo

    2010-01-01

    The checklist of grasses from Colombian Guayana is presented. In all, 152 species, 69 genera, and six subfamilies were recorded. Thus, in the Colombian Guayana is represented the 18.7 and 43.7% of the species and genera of Colombian grasses, respectively. The subfamilies with the highest number of species were Panicoideae (110 species/46 genera), Chloridoideae (21/9), and Bambusoideae (11/9). The most diverse genera were Paspalum (19 species), Panicum (16), Axonopus (14), Eragrostis (9), and Digitaria (8). Nineteen species are introduced and naturalized in the Colombian Guayana, which represent 12.5% of the agrostological flora for the Colombian Guayana. There were 8 endemic species (5.3% of Colombian Guayanan grasses). In addition, some species are reported for the first time for Colombian flora (belonging to Axonopus, Cyphonanthus, Gymnopogon, and Paspalum), and some species are new to science (belonging to Axonopus, Digitaria, Eragrostis, and Sacciolepis). On the other hand, some preliminary biogeographical aspect are analyzed Flora of Colombia,

  19. Phytoextraction and accumulation of mercury in three plant species: Indian mustard (Brassica juncea), beard grass (Polypogon monospeliensis), and Chinese brake fern (Pteris vittata).

    Science.gov (United States)

    Su, Yi; Han, Fengxiang X; Chen, Jian; Sridhar, B B Maruthi; Monts, David L

    2008-01-01

    The objective of this research was to screen and search for suitable plant species to phytoextract mercury-contaminated soil. Our effort focused on using some of the known metal-accumulating wild-type plants since no natural plant species with mercury-hyperaccumulat ing properties has yet been identified. Three plant species were evaluated for their uptake efficiency for mercury: Indian mustard (Brassica juncea), beard grass (Polypogon monospeliensis), and Chinese brake fern (Pteris vittata). Four sets of experiments were conducted to evaluate the phytoremediation potential of these three plant species: a pot study with potting mix where mercury was provided daily as HgCl2 solution; experiments with freshly mercury-spiked soil; and a study with aged soils contaminated with different mercury sources (HgCl2, Hg(NO3)2, and HgS). Homemade sunlit chambers were also used to study foliar uptake of Hg from ambient air. Among the three plant species, Chinese brake fern showed the least stress symptoms resulting from mercury exposure and had the highest mercury accumulation. Our results indicate that Chinese brake fern may be a potential candidate for mercury phytoextraction. We found that mercury contamination is biologically available for plant uptake and accumulation, even if the original and predominating mercury form is HgS, and also after multiple phytoremediation cycles.

  20. 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.

  1. Patogenicidade de Helminthosporium oryzae a algumas espécies de gramíneas Pathogenicity of Helminthosporium oryzae against some grass species

    Directory of Open Access Journals (Sweden)

    V.H. Artigiani Filho

    1995-04-01

    Full Text Available O fungo Helminthosporium oryzae é um patógeno do arroz. Devido a sua variabilidade patogênica, foi investigada a possibilidade deste fungo infectar outras gramíneas. Através de inoculação artificial, ficou demonstrada a capacidade deste patógeno provocar infecção em aveia, cana, centeio, sorgo, trigo, Brachiaria decumbens e Panicum maximum. Assim, estas espécies vegetais podem ser consideradas potenciais hospedeiros do fungo na natureza.Helminthosporium oryzae is a rice pathogen. Due to its variability in pathogenicity, the possibility of this fungus Infecting other grasses was investigated. The capacity of this pathogen was demonstrated to be able to infect oat, sugar-cane, rye, sorghum, wheat, Brachiaria decumbens and Panicum maximum through artificial inoculations. Therefore, those plant species can be considered potencial hosts for the fungus in nature.

  2. Trypanosoma teixeirae: A new species belonging to the T. cruzi clade causing trypanosomosis in an Australian little red flying fox (Pteropus scapulatus).

    Science.gov (United States)

    Barbosa, Amanda D; Mackie, John T; Stenner, Robyn; Gillett, Amber; Irwin, Peter; Ryan, Una

    2016-06-15

    Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Determining Optimal New Generation Satellite Derived Metrics for Accurate C3 and C4 Grass Species Aboveground Biomass Estimation in South Africa

    Directory of Open Access Journals (Sweden)

    Cletah Shoko

    2018-04-01

    Full Text Available While satellite data has proved to be a powerful tool in estimating C3 and C4 grass species Aboveground Biomass (AGB, finding an appropriate sensor that can accurately characterize the inherent variations remains a challenge. This limitation has hampered the remote sensing community from continuously and precisely monitoring their productivity. This study assessed the potential of a Sentinel 2 MultiSpectral Instrument, Landsat 8 Operational Land Imager, and WorldView-2 sensors, with improved earth imaging characteristics, in estimating C3 and C4 grasses AGB in the Cathedral Peak, South Africa. Overall, all sensors have shown considerable potential in estimating species AGB; with the use of different combinations of the derived spectral bands and vegetation indices producing better accuracies. However, WorldView-2 derived variables yielded better predictive accuracies (R2 ranging between 0.71 and 0.83; RMSEs between 6.92% and 9.84%, followed by Sentinel 2, with R2 between 0.60 and 0.79; and an RMSE 7.66% and 14.66%. Comparatively, Landsat 8 yielded weaker estimates, with R2 ranging between 0.52 and 0.71 and high RMSEs ranging between 9.07% and 19.88%. In addition, spectral bands located within the red edge (e.g., centered at 0.705 and 0.745 µm for Sentinel 2, SWIR, and NIR, as well as the derived indices, were found to be very important in predicting C3 and C4 AGB from the three sensors. The competence of these bands, especially of the free-available Landsat 8 and Sentinel 2 dataset, was also confirmed from the fusion of the datasets. Most importantly, the three sensors managed to capture and show the spatial variations in AGB for the target C3 and C4 grassland area. This work therefore provides a new horizon and a fundamental step towards C3 and C4 grass productivity monitoring for carbon accounting, forage mapping, and modelling the influence of environmental changes on their productivity.

  4. Establishment, Growth and Biomass yield of three Grass species on a degraded Ultisol and their effect on soil loss.

    Directory of Open Access Journals (Sweden)

    2016-11-01

    Full Text Available Erosion is a cause for concern; this is because of its effects on the soil used for both agricultural and non-agricultural purposes. Experiments were carried out to check the establishment, growth and biomass field of 3 tropical plants and their effects on soil loss during 2007 planting season. The treatments comprised 3 grasses viz. Azonopus compressus. Panicum maximum and Andropogon gayanus. The grasses were laid our in the field using a randomized complete block design replicated 4 times. Bare soil was used as the control. The parameters tested were plant height, leaf area index, root density, root establishment and the amount of soil loss using erosion pins. The result showed that Andropogon gayanus has an edge over Panicum maximum and Axonopus compressus with reference to plant height, root establishment, root density and leaf area index. Andropogon gayanus had a higher plant height from 3,6,9 and 12WAP with plant heights of 3.30cm, 3.63cm,3.93cm and 4.30cm representing 15.7%, 19.3% and 28.8% respectively. It was followed by P. maximum while A. compressus maintained the lowest plant height from 3,6,9 and 12 WAP with plant height of 2.83cm, 3.05cm, 3.20cm and 3.45cm respectively. In terms of root density, A. compressus did not have much root density which was 0.02t/ha, also at 12WAP, P. maximum did not have much root density which was 0.06t/ha though it was higher than A. compressus. The trend was the same for A. gayanus whose root density was 0.75t/ha. In terms of leaf area index (LAI, it was shown that at 3WAP and 6WAP, A. compressus had the lowest leaf area index of 58.25 and 65.75 respectively. Also at 9WAP and 12WAP A. compressus had 72.28 and 75.08t/ha respectively. At 3WAP and 6WAP P.maximum had a high leaf area index of 66.60 and 77.25 respectively. A. gayanus at 3WAP and 6WAP had 87.73 gayanus at 3WAP and 6WAP had 87.73 and 90.80 for 9WAP and 12WAP respectively. A. compressus protected the soil, reducing soil loss as a total of 9

  5. The ITS1-5.8S rRNA gene -ITS2 sequence variability during the divergence of sweet-grass species (gen us Glyceria R. Br.

    Directory of Open Access Journals (Sweden)

    Alexander V Rodionov

    2011-12-01

    Full Text Available Comparative analysis of the sequence ITS1-5.8S rRNA gene-ITS2 of the nuclear genome of 13 species of genus Glyceria, 4 species of Melica and a species of monotypic genus Pleuropogon showed that the species of the genus Glyceria have 3 haplotypes: 1 Haplotype A was found only in species of the subgenus Glyceria section Glyceria (G. septentrionalis, G. fluitans, G. declinata, G. occidentalis, G. notata, G. borealis, G. leptostachya and in Pleuropogon sabinii; 2 Haplotype C is characteristic of the subgenus Hydropoa, section Hydropoa (G. grandis, G. х amurensis, G. triflora, G. maxima and sect. Lithuanicae (G. leptolepis; 3 Haplotype B is found in the species of the subgenus Hydropoa sections Striatae (G. elata, G. striata, G. neogaea, G. canadensis, Scolochloiformes (G. alnasteretum, G. spiculosa and G. lithuanica of sect. Lithuanicae. Species carring haplotype B are located at the base of the phylogenetic tree of the genus Glyceria and/or clustered with low bootstrap indices. On the phylogenetic trees inferred by the analysis of the sequences ITS and 5.8S rDNA both sect. Glyceria and sect. Hydropoa represented two sister monophyly branches. The species Pleuropogon sabinii belong to the branch of subgenus Glyceria as a sister monotypic branch to the branch of the sect. Glyceria.

  6. Grass genomes

    OpenAIRE

    Bennetzen, Jeffrey L.; SanMiguel, Phillip; Chen, Mingsheng; Tikhonov, Alexander; Francki, Michael; Avramova, Zoya

    1998-01-01

    For the most part, studies of grass genome structure have been limited to the generation of whole-genome genetic maps or the fine structure and sequence analysis of single genes or gene clusters. We have investigated large contiguous segments of the genomes of maize, sorghum, and rice, primarily focusing on intergenic spaces. Our data indicate that much (>50%) of the maize genome is composed of interspersed repetitive DNAs, primarily nested retrotransposons that in...

  7. Ambiguity in urban belonging

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin; Simonsen, Kirsten

    2015-01-01

    mapping of life as an ethnic minority in the city. It revolves around three issues. First, it focuses on the narrators’ experiences of exclusions and blockages in everyday life. This is followed by a focus on urban belonging emphasizing its differential character. Finally, the ambiguity of experiences...

  8. Grass species influence on plant N uptake - Determination of atmospheric N deposition to a semi-natural peat bog site using a 15N labelling approach

    Science.gov (United States)

    Hurkuck, Miriam; Brümmer, Christian; Spott, Oliver; Flessa, Heinz; Kutsch, Werner L.

    2014-05-01

    Large areas of natural peat bogs in Northwestern Germany have been converted to arable land and were subjected to draining and peat cutting in the past. The few protected peatland areas remaining are affected by high nitrogen (N) deposition. Our study site - a moderately drained raised bog - is surrounded by highly fertilized agricultural land and livestock production. In this study, we used a 15N pool dilution technique called 'Integrated Total Nitrogen Input' (ITNI) to quantify annual deposition of atmospheric N into biomonitoring pots over a two-year period. Since it considers direct N uptake by plants, it was expected to result in higher N input than conventional methods for determination of N deposition (e.g. micrometeorological approaches, bulk N samplers). Using Lolium multiflorum and Eriophorum vaginatum as monitor plants and low, medium and high levels of fertilization, we aimed to simulate increasing N deposition to planted pots and to allocate airborne N after its uptake by the soil-plant system in aboveground biomass, roots and soil. Increasing N fertilization was positively correlated with biomass production of Eriophorum vaginatum, whereas atmospheric plant N uptake decreased and highest airborne N input of 899.8 ± 67.4 µg N d-1 pot-1 was found for low N fertilization. In contrast, Lolium multiflorum showed a clear dependency of N supply on plant N uptake and was highest (688.7 ± 41.4 µg N d-1 pot-1) for highly fertilized vegetation pots. Our results suggest that grass species respond differently to increasing N input. While crop grasses such as Lolium multiflorum take up N according to N availability, species adopted to nutrient-limited conditions like Eriophorum vaginatum show N saturation effects with increasing N supply. Total airborne N input ranged from about 24 to 66 kg N ha-1 yr-1 dependent on the used indicator plant and the amount of added fertilizer. Parallel determination of atmospheric N deposition using a micrometeorological approach

  9. Molecular Typing and Phylogenetic Analysis of Some Species Belonging to Phlebotomus (Larroussius and Phlebotomus (Adlerius Subgenera (Diptera: Psychodidae from Two Locations in Iran

    Directory of Open Access Journals (Sweden)

    P Parvizi

    2010-12-01

    Full Text Available Background: Haematophagous females of some phlebotomine sandflies are the only natural vectors of Leishmania species, the causative agents of leishmaniasis in many parts of the tropics and subtropics, including Iran.  We report the presence of Phlebotomus (Larroussius major and Phlebotomus (Adlerius halepensis in Tonekabon (Ma­zanderan Province and Phlebotomus (Larroussius tobbi in Pakdasht (Tehran Province. It is the first report of these species, known as potential vectors of zoonotic visceral leishmaniasis in Iran, are identified in these areas.Methods: In 2006-2007 individual wild-caught sandflies were characterized by both morphological features and sequence analysis of their mitochondrial genes (Cytochrome b.  The analyses were based on a fragment of  494 bp at the 3´ end of the Cyt b gene (Cyt b 3´ fragment and a fragment of  382 bp CB3 at the 5´ end of the Cyt b gene (Cyt b 5´ fragment. We also analysed the Cyt b Long fragment, which is located on the last 717 bp of the Cyt b gene, followed by 20 bp of intergenic spacer and the transfer RNA ser(TCN gene.Results: Twenty-seven P. halepensis and four P. major from Dohezar, Tonekabon, Mazanderan province and 8 P. tobbi from Packdasht, Tehran Province were identified by morphological and molecular characters. Cyt b 5´ and Cyt b 3´ fragment sequences were obtained from 15 and 9 flies, respectively. Cyt b long fragment sequences were ob­tained from 8 out of 27 P. halepensis.Conclusion: Parsimony analyses (using heuristic searches of the DNA sequences of Cyt b always showed mono­phyletic clades of subgenera and each species did form a monophyletic group.

  10. Molecular typing and phylogenetic analysis of some species belonging to phlebotomus (larroussius) and phlebotomus (adlerius) subgenera (Diptera: psychodidae) from two locations in iran.

    Science.gov (United States)

    Parvizi, P; Naddaf, S R; Alaeenovin, E

    2010-01-01

    Haematophagous females of some phlebotomine sandflies are the only natural vectors of Leishmania species, the causative agents of leishmaniasis in many parts of the tropics and subtropics, including Iran. We report the presence of Phlebotomus (Larroussius) major and Phlebotomus (Adlerius) halepensis in Tonekabon (Mazanderan Province) and Phlebotomus (Larroussius) tobbi in Pakdasht (Tehran Province). It is the first report of these species, known as potential vectors of zoonotic visceral leishmaniasis in Iran, are identified in these areas. In 2006-2007 individual wild-caught sandflies were characterized by both morphological features and sequence analysis of their mitochondrial genes (Cytochrome b). The analyses were based on a fragment of 494 bp at the 3' end of the Cyt b gene (Cyt b 3' fragment) and a fragment of 382 bp CB3 at the 5' end of the Cyt b gene (Cyt b 5' fragment). We also analysed the Cyt b Long fragment, which is located on the last 717 bp of the Cyt b gene, followed by 20 bp of intergenic spacer and the transfer RNA ser(TCN) gene. Twenty-seven P. halepensis and four P. major from Dohezar, Tonekabon, Mazanderan province and 8 P. tobbi from Packdasht, Tehran Province were identified by morphological and molecular characters. Cyt b 5' and Cyt b 3' fragment sequences were obtained from 15 and 9 flies, respectively. Cyt b long fragment sequences were obtained from 8 out of 27 P. halepensis. Parsimony analyses (using heuristic searches) of the DNA sequences of Cyt b always showed monophyletic clades of subgenera and each species did form a monophyletic group.

  11. Molecular Typing and Phylogenetic Analysis of Some Species Belonging to Phlebotomus (Larroussius and Phlebotomus (Adlerius Subgenera (Diptera: Psychodidae from Two Locations in Iran

    Directory of Open Access Journals (Sweden)

    E AlaeeNovin

    2010-12-01

    Full Text Available "nAbstract"nBackground: Haematophagous females of some phlebotomine sandflies are the only natural vectors of Leishmania species, the causative agents of leishmaniasis in many parts of the tropics and subtropics, including Iran.  We report the presence of Phlebotomus (Larroussius major and Phlebotomus (Adlerius halepensis in Tonekabon (Ma­zanderan Province and Phlebotomus (Larroussius tobbi in Pakdasht (Tehran Province. It is the first report of these species, known as potential vectors of zoonotic visceral leishmaniasis in Iran, are identified in these areas."nMethods: In 2006-2007 individual wild-caught sandflies were characterized by both morphological features and sequence analysis of their mitochondrial genes (Cytochrome b.  The analyses were based on a fragment of  494 bp at the 3´ end of the Cyt b gene (Cyt b 3´ fragment and a fragment of  382 bp CB3 at the 5´ end of the Cyt b gene (Cyt b 5´ fragment. We also analysed the Cyt b Long fragment, which is located on the last 717 bp of the Cyt b gene, followed by 20 bp of intergenic spacer and the transfer RNA ser(TCN gene."nResults: Twenty-seven P. halepensis and four P. major from Dohezar, Tonekabon, Mazanderan province and 8 P. tobbi from Packdasht, Tehran Province were identified by morphological and molecular characters. Cyt b 5´ and Cyt b 3´ fragment sequences were obtained from 15 and 9 flies, respectively. Cyt b long fragment sequences were ob­tained from 8 out of 27 P. halepensis."nConclusion: Parsimony analyses (using heuristic searches of the DNA sequences of Cyt b always showed mono­phyletic clades of subgenera and each species did form a monophyletic group. "nKeywords: Mitochondrial Cytochrome b, Phlebotomus (Larroussius major, Phlebotomus (Larroussius tobbi, Phlebotomus (Adlerius halepensis, Iran

  12. Unraveling the diversification history of grasshoppers belonging to the “Trimerotropis pallidipennis” (Oedipodinae: Acrididae species group: a hotspot of biodiversity in the Central Andes

    Directory of Open Access Journals (Sweden)

    Noelia Verónica Guzmán

    2017-09-01

    Full Text Available The Andean Mountain range has been recognized as one of the biodiversity hotspots of the world. The proposed mechanisms for such species diversification, among others, are due to the elevation processes occurring during the Miocene and the intensive glacial action during the Pleistocene. In this study we investigated the diversification history of the grasshopper Trimerotropis pallidipennis species complex which shows a particularly wide latitudinal and altitudinal distribution range across the northern, central and southern Andes in South America. Many genetic lineages of this complex have been so far discovered, making it an excellent model to investigate the role of the central Andes Mountains together with climatic fluctuations as drivers of speciation. Phylogenetics, biogeographic and molecular clock analyses using a multi-locus dataset revealed that in Peru there are at least two, and possibly four genetic lineages. Two different stocks originated from a common ancestor from North/Central America—would have dispersed toward southern latitudes favored by the closure of the Panama Isthmus giving rise to two lineages, the coastal and mountain lineages, which still coexist in Peru (i.e., T. pallidipennis and T. andeana. Subsequent vicariant and dispersal events continued the differentiation process, giving rise to three to six genetic lineages (i.e., clades detected in this study, which were geographically restricted to locations dispersed over the central Andes Mountains in South America. Our results provide another interesting example of “island diversification” motored by the topography plus unstable climatic conditions during the Pleistocene, pointing out the presence of a hotspot of diversification in the Andean region of Peru.

  13. Targeted genotyping-by-sequencing permits cost-effective identification and discrimination of pasture grass species and cultivars.

    Science.gov (United States)

    Pembleton, Luke W; Drayton, Michelle C; Bain, Melissa; Baillie, Rebecca C; Inch, Courtney; Spangenberg, German C; Wang, Junping; Forster, John W; Cogan, Noel O I

    2016-05-01

    A targeted amplicon-based genotyping-by-sequencing approach has permitted cost-effective and accurate discrimination between ryegrass species (perennial, Italian and inter-species hybrid), and identification of cultivars based on bulked samples. Perennial ryegrass and Italian ryegrass are the most important temperate forage species for global agriculture, and are represented in the commercial pasture seed market by numerous cultivars each composed of multiple highly heterozygous individuals. Previous studies have identified difficulties in the use of morphophysiological criteria to discriminate between these two closely related taxa. Recently, a highly multiplexed single nucleotide polymorphism (SNP)-based genotyping assay has been developed that permits accurate differentiation between both species and cultivars of ryegrasses at the genetic level. This assay has since been further developed into an amplicon-based genotyping-by-sequencing (GBS) approach implemented on a second-generation sequencing platform, allowing accelerated throughput and ca. sixfold reduction in cost. Using the GBS approach, 63 cultivars of perennial, Italian and interspecific hybrid ryegrasses, as well as intergeneric Festulolium hybrids, were genotyped. The genetic relationships between cultivars were interpreted in terms of known breeding histories and indistinct species boundaries within the Lolium genus, as well as suitability of current cultivar registration methodologies. An example of applicability to quality assurance and control (QA/QC) of seed purity is also described. Rapid, low-cost genotypic assays provide new opportunities for breeders to more fully explore genetic diversity within breeding programs, allowing the combination of novel unique genetic backgrounds. Such tools also offer the potential to more accurately define cultivar identities, allowing protection of varieties in the commercial market and supporting processes of cultivar accreditation and quality assurance.

  14. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... by agricultural practices as well as environmental factors, traits related to seed production reveal considerable genetic variation, prerequisite for improvement by direct or indirect selection. This chapter first reports on the biological and physiological basics of the grass reproduction system, then highlights...... 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....

  15. Variation in important pasture grasses: I. Morphological and ...

    African Journals Online (AJOL)

    Variation in important pasture grasses: I. Morphological and geographical variation. ... Seven species are important pasture grasses throughout the western Transvaal, Orange Free State, northern Cape and Natal. ... Language: English.

  16. Multi-locus sequence typing provides epidemiological insights for diseased sharks infected with fungi belonging to the Fusarium solani species complex.

    Science.gov (United States)

    Desoubeaux, Guillaume; Debourgogne, Anne; Wiederhold, Nathan P; Zaffino, Marie; Sutton, Deanna; Burns, Rachel E; Frasca, Salvatore; Hyatt, Michael W; Cray, Carolyn

    2018-07-01

    Fusarium spp. are saprobic moulds that are responsible for severe opportunistic infections in humans and animals. However, we need epidemiological tools to reliably trace the circulation of such fungal strains within medical or veterinary facilities, to recognize environmental contaminations that might lead to infection and to improve our understanding of factors responsible for the onset of outbreaks. In this study, we used molecular genotyping to investigate clustered cases of Fusarium solani species complex (FSSC) infection that occurred in eight Sphyrnidae sharks under managed care at a public aquarium. Genetic relationships between fungal strains were determined by multi-locus sequence typing (MLST) analysis based on DNA sequencing at five loci, followed by comparison with sequences of 50 epidemiologically unrelated FSSC strains. Our genotyping approach revealed that F. keratoplasticum and F. solani haplotype 9x were most commonly isolated. In one case, the infection proved to be with another Hypocrealian rare opportunistic pathogen Metarhizium robertsii. Twice, sharks proved to be infected with FSSC strains with the same MLST sequence type, supporting the hypothesis the hypothesis that common environmental populations of fungi existed for these sharks and would suggest the longtime persistence of the two clonal strains within the environment, perhaps in holding pools and life support systems of the aquarium. This study highlights how molecular tools like MLST can be used to investigate outbreaks of microbiological disease. This work reinforces the need for regular controls of water quality to reduce microbiological contamination due to waterborne microorganisms.

  17. Soil Microorganisms Alleviate the Allelochemical Effects of a Thyme Monoterpene on the Performance of an Associated Grass Species

    OpenAIRE

    Ehlers, Bodil K.

    2011-01-01

    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...

  18. Holocene re-colonisation, central-marginal distribution and habitat specialisation shape population genetic patterns within an Atlantic European grass species.

    Science.gov (United States)

    Harter, D E V; Jentsch, A; Durka, W

    2015-05-01

    Corynephorus canescens (L.) P.Beauv. is an outbreeding, short-lived and wind-dispersed grass species, highly specialised on scattered and disturbance-dependent habitats of open sandy sites. Its distribution ranges from the Iberian Peninsula over Atlantic regions of Western and Central Europe, but excludes the two other classical European glacial refuge regions on the Apennine and Balkan Peninsulas. To investigate genetic patterns of this uncommon combination of ecological and biogeographic species characteristics, we analysed AFLP variation among 49 populations throughout the European distribution range, expecting (i) patterns of SW European glacial refugia and post-glacial expansion to the NE; (ii) decreasing genetic diversity from central to marginal populations; and (iii) interacting effects of high gene flow and disturbance-driven genetic drift. Decreasing genetic diversity from SW to NE and distinct gene pool clustering imply refugia on the Iberian Peninsula and in western France, from where range expansion originated towards the NE. High genetic diversity within and moderate genetic differentiation among populations, and a significant pattern of isolation-by-distance indicate a gene flow drift equilibrium within C. canescens, probably due to its restriction to scattered and dynamic habitats and limited dispersal distances. These features, as well as the re-colonisation history, were found to affect genetic diversity gradients from central to marginal populations. Our study emphasises the need for including the specific ecology into analyses of species (re-)colonisation histories and range centre-margin analyses. To account for discontinuous distributions, new indices of marginality were tested for their suitability in studies of centre-periphery gradients. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Effect of nitrogen fertilization, grass species and cultivar on sod production on Valkeasuo peat bog - a case study

    Directory of Open Access Journals (Sweden)

    Perttu Virkajärvi

    1997-09-01

    Full Text Available As part of a research project concerning the agricultural utilization of cut-away peat bogs, a sod production experiment was conducted at Valkeasuo, Tohmajärvi, in 1990-1993. The aim of the experiment was to study the effect of nitrogen and choice of cultivar on sod production and sod quality on peat bogs. The N fertilization rates were 50, 100 and 150kg ha-1. The Poa pratensis cultivars were ‘Conni’, ‘Cynthia’, ‘Haga’ and ‘Julia’, the Festuca rubra cultivars were ‘Center’, ‘Juliska’, ‘Koket’ and ‘Näpsä’ and the Agrostis capillaris cultivar was ‘Rasti’. Two mixtures of P. pratensis/F. rubra and one of A. capillaris/F. rubra imitated commercial sod products. Increasing of N fertilization from 50 kg up to 150 kg ha-1 a had positive effect on general the quality of sod as well as on the green cover before and after transplanting. It increased the thatch formation. The positive effect of N on the number of tillers and green cover in the year following transplanting was dependent on the species and the cultivar. Species and cultivar affected all measured variables excluding thatch formation. Generally, the P. pratensis cultivars tested suited better for sod production than cultivars of F. rubra, but there were clear differences between cultivars within species as well. Although the soil was infertile, the contents of Ca, K, Mg, P, Cu, Fe, Mn, Mo and Zn in the herbage samples were within normal range. The botanical purity was high, which supports the hypothesis that the absence of seed bank of weeds on peat bogs immediately after harvesting the peat can be utilized.

  20. Performing Belonging, celebrating invisibility?

    DEFF Research Database (Denmark)

    Juul, Kristine

    2014-01-01

    Serbian migrants living transnational lives consciously or unconsciously move between visibility and invisibility in their performance of migrant success stories. A case in point are public festivals, performed to make visible migrants’ successful inclusion in Danish society, i.e. celebrating...... invisibility. Meanwhile, other celebrations are consciously relegated to the invisible confines of the Serbian homeland. This article analyses celebrations in Denmark and in Serbia and shows how visible displays of ethnicity and difference tend to turn into easily palatable heritage versions of Serbian culture...... when performed in a Danish context. In turn, the visibility acquired through celebrations of migrants’ belonging in their homeland is inclined to render invisible those who did not take part in the migration experience....

  1. Biosurfactant-producing microorganism Pseudomonas sp. SB assists the phytoremediation of DDT-contaminated soil by two grass species.

    Science.gov (United States)

    Wang, Beibei; Wang, Qingling; Liu, Wuxing; Liu, Xiaoyan; Hou, Jinyu; Teng, Ying; Luo, Yongming; Christie, Peter

    2017-09-01

    Phytoremediation together with microorganisms may confer the advantages of both phytoremediation and microbial remediation of soils containing organic contaminants. In this system biosurfactants produced by Pseudomonas sp. SB may effectively help to increase the bioavailability of organic pollutants and thereby enhance their microbial degradation in soil. Plants may enhance the rhizosphere environment for microorganisms and thus promote the bioremediation of contaminants. In the present pot experiment study, dichlorodiphenyltrichloroethane (DDT) residues underwent an apparent decline after soil bioremediation compared with the original soil. The removal efficiency of fertilizer + tall fescue, fertilizer + tall fescue + Pseudomonas, fertilizer + perennial ryegrass, and fertilizer + perennial ryegrass + Pseudomonas treatments were 59.4, 65.6, 69.0, and 65.9%, respectively, and were generally higher than that in the fertilizer control (40.3%). Principal coordinates analysis (PCoA) verifies that plant species greatly affected the soil bacterial community irrespective of inoculation with Pseudomonas sp. SB. Furthermore, community composition analysis shows that Proteobacteria, Acidobacteria and Actinobacteria were the three dominant phyla in all groups. In particular, the relative abundance of Pseudomonas for fertilizer + tall fescue + Pseudomonas (0.25%) was significantly greater than fertilizer + tall fescue and this was related to the DDT removal efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. SQ grass sublingual allergy immunotherapy tablet for disease-modifying treatment of grass pollen allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Dahl, Ronald; Roberts, Graham; de Blic, Jacques

    2016-01-01

    BACKGROUND: Allergy immunotherapy is a treatment option for allergic rhinoconjunctivitis (ARC). It is unique compared with pharmacotherapy in that it modifies the immunologic pathways that elicit an allergic response. The SQ Timothy grass sublingual immunotherapy (SLIT) tablet is approved in North...... America and throughout Europe for the treatment of adults and children (≥5 years old) with grass pollen-induced ARC. OBJECTIVE: The clinical evidence for the use of SQ grass SLIT-tablet as a disease-modifying treatment for grass pollen ARC is discussed in this review. METHODS: The review included...... the suitability of SQ grass SLIT-tablet for patients with clinically relevant symptoms to multiple Pooideae grass species, single-season efficacy, safety, adherence, coseasonal initiation, and cost-effectiveness. The data from the long-term SQ grass SLIT-tablet clinical trial that evaluated a clinical effect 2...

  3. Interspecific and intraspecific hybrid Epichloë species symbiotic with the North American native grass Poa alsodes.

    Science.gov (United States)

    Shymanovich, Tatsiana; Charlton, Nikki D; Musso, Ashleigh M; Scheerer, Jonathan; Cech, Nadja B; Faeth, Stanley H; Young, Carolyn A

    2017-01-01

    The endophyte presence and diversity in natural populations of Poa alsodes were evaluated along a latitudinal transect from the southern distribution range in North Carolina to New York. Two distinct Epichloë hybrid taxa were identified from 23 populations. Each taxon could easily be distinguished by polymerase chain reaction (PCR) genotyping with primers designed to mating type genes and alkaloid biosynthesis genes that encode key pathway steps for ergot alkaloids, indole-diterpenes, lolines, and peramine. The most commonly found Epichloë taxon, Poa alsodes Taxonomic Group-1 (PalTG-1), was detected in 22 populations at high infection frequencies (72-100%), with the exception of one population at high elevation (26% infection). The second taxon, PalTG-2, was observed only in five populations in Pennsylvania constituting 12% of infected samples. Phylogenetic analyses placed PalTG-1 as an interspecific hybrid of E. amarillans and E. typhina subsp. poae ancestors, and it is considered a new hybrid species, which the authors name Epichloë alsodes. PalTG-2 is an intraspecific hybrid of two E. typhina subsp. poae ancestors, similar to E. schardlii from the host Cinna arundinacea, which the authors propose as a new variety, Epichloë schardlii var. pennsylvanica. Epichloë alsodes isolates were all mating type MTA MTB and tested positive for dmaW, easC, perA, and some LOL genes, but only the alkaloid N-acetylnorloline was detected in E. alsodes-infected plant material. Epichloë schardlii var. pennsylvanica isolates were all mating type MTB MTB and tested positive for perA, but peramine was not produced. Both E. alsodes and E. schardlii var. pennsylvanica appeared to have complete perA genes, but point mutations were identified in E. alsodes that would render the encoded perA gene nonfunctional.

  4. The power of belonging

    Directory of Open Access Journals (Sweden)

    Gjøtterud Sigrid

    2017-12-01

    Full Text Available Coming from a Nordic environment, professionally working in teacher education, both authors engaged in developmental work and research in the Uluguru mountains in Tanzania. The research is carried out in a community-based organization for vulnerable youth, Mgeta Orphan Education Foundation (MOEF, which builds on principles of action learning and action research. We have followed and participated in the development of the organization since 2010, and this article builds on data gathered in 2016-17. We will show and discuss some of the transformations we have witnessed, mainly in the older members. The transformations seem to have an emergent character, and we examine further factors we have seen as crucial for transforming the lives of the young people in the orphan education project. Surprisingly, duty was a factor coming forth in the data. The youth perceived duty in a relational way, mainly caused by inner motivation nurtured by the example of their coordinator, Solomon, and by facing the continuous, emergent need for assistance in their local communities. Less surprisingly, belonging transpired as a fundamental factor. Previously, we have analyzed the transformational learning among the youngsters, and identified a set of transformational tools (Gjotterud, Krogh, Dyngeland, & Mwakasumba, 2015. Building on the transformational tools, we have derived a model for Relational Transformation. Transformative action research is the approach we follow, and one aim of this article is to contribute to the understanding of the reciprocity of transformative processes in transformative research.

  5. Names of Southern African grasses: Name changes and additional ...

    African Journals Online (AJOL)

    The main reasons for changes in botanical names are briefly reviewed, with examples from the lists. At this time, about 1040 grass species and subspecific taxa are recognized in the subcontinent. Keywords: botanical research; botanical research institute; botany; grass; grasses; identification; name change; nomenclature; ...

  6. Response of dominant grass and shrub species to water manipulation: an ecophysiological basis for shrub invasion in a Chihuahuan Desert grassland.

    Science.gov (United States)

    Throop, Heather L; Reichmann, Lara G; Sala, Osvaldo E; Archer, Steven R

    2012-06-01

    Increases in woody vegetation and declines in grasses in arid and semi-arid ecosystems have occurred globally since the 1800s, but the mechanisms driving this major land-cover change remain uncertain and controversial. Working in a shrub-encroached grassland in the northern Chihuahuan Desert where grasses and shrubs typically differ in leaf-level nitrogen allocation, photosynthetic pathway, and root distribution, we asked if differences in leaf-level ecophysiology could help explain shrub proliferation. We predicted that the relative performance of grasses and shrubs would vary with soil moisture due to the different morphological and physiological characteristics of the two life-forms. In a 2-year experiment with ambient, reduced, and enhanced precipitation during the monsoon season, respectively, the encroaching C(3) shrub (honey mesquite Prosopis glandulosa) consistently and substantially outperformed the historically dominant C(4) grass (black grama Bouteloua eriopoda) in terms of photosynthetic rates while also maintaining a more favorable leaf water status. These differences persisted across a wide range of soil moisture conditions, across which mesquite photosynthesis was decoupled from leaf water status and moisture in the upper 50 cm of the soil profile. Mesquite's ability to maintain physiologically active leaves for a greater fraction of the growing season than black grama potentially amplifies and extends the importance of physiological differences. These physiological and phenological differences may help account for grass displacement by shrubs in drylands. Furthermore, the greater sensitivity of the grass to low soil moisture suggests that grasslands may be increasingly susceptible to shrub encroachment in the face of the predicted increases in drought intensity and frequency in the desert of the southwestern USA.

  7. 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.

  8. Checklist of Serengeti Ecosystem Grasses

    Science.gov (United States)

    Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    Abstract We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761

  9. Checklist of Serengeti Ecosystem Grasses.

    Science.gov (United States)

    Williams, Emma Victoria; Elia Ntandu, John; Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution.

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

    CSIR Research Space (South Africa)

    Tjelele, J

    2015-02-01

    Full Text Available 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...

  11. How to Understand Custodial Belonging

    Directory of Open Access Journals (Sweden)

    Ann Game

    2013-08-01

    Full Text Available Debates about ecological responsibility are interested in different forms of belonging. This article develops an understanding of a custodial form of belonging based on the logic of relation, which we distinguish from a proprietorial form of belonging based on the logic of identity. Theorists working on questions of belonging use a language of custodianship when describing a sense of responsibility and care that arises through connection or relation. We argue, however, that the full significance of custodial belonging cannot be appreciated when understandings of connection are derived from within the terms of identity logic. In other words, when belonging is understood in terms of identity and identification, custodianship is inadvertently reduced to a proprietorial form of responsibility and care. We develop this argument by addressing Australian research on custodial belonging. Focusing on the influential work of Deborah Bird Rose, we argue that there are tensions between, on the one hand, her attempts to recognise connected forms of belonging, and, on the other, her conceptual reliance on the assumptions of identity logic. Our primary concern here is to indicate relational possibilities in her work precluded by the language of identity. In particular, we suggest that the concept of ecological being allows for a specificity and inclusiveness that are not recognised by Rose’s concept of the ‘ecologically emplaced self’.

  12. Pennisetum section Brevivalvula in West Africa : morphological and genetic variation in an agamic species complex

    NARCIS (Netherlands)

    Schmelzer, G.H.

    1998-01-01

    Section Brevivalvula is one of five sections in the large tropical grass genus Pennisetum . It belongs to the tertiary genepool of P. glaucum (L.) R. Br., pearl millet, and consists of six morphological species: P.

  13. Comparative and Evolutionary Analysis of Grass Pollen Allergens Using Brachypodium distachyon as a Model System.

    Directory of Open Access Journals (Sweden)

    Akanksha Sharma

    Full Text Available Comparative genomics have facilitated the mining of biological information from a genome sequence, through the detection of similarities and differences with genomes of closely or more distantly related species. By using such comparative approaches, knowledge can be transferred from the model to non-model organisms and insights can be gained in the structural and evolutionary patterns of specific genes. In the absence of sequenced genomes for allergenic grasses, this study was aimed at understanding the structure, organisation and expression profiles of grass pollen allergens using the genomic data from Brachypodium distachyon as it is phylogenetically related to the allergenic grasses. Combining genomic data with the anther RNA-Seq dataset revealed 24 pollen allergen genes belonging to eight allergen groups mapping on the five chromosomes in B. distachyon. High levels of anther-specific expression profiles were observed for the 24 identified putative allergen-encoding genes in Brachypodium. The genomic evidence suggests that gene encoding the group 5 allergen, the most potent trigger of hay fever and allergic asthma originated as a pollen specific orphan gene in a common grass ancestor of Brachypodium and Triticiae clades. Gene structure analysis showed that the putative allergen-encoding genes in Brachypodium either lack or contain reduced number of introns. Promoter analysis of the identified Brachypodium genes revealed the presence of specific cis-regulatory sequences likely responsible for high anther/pollen-specific expression. With the identification of putative allergen-encoding genes in Brachypodium, this study has also described some important plant gene families (e.g. expansin superfamily, EF-Hand family, profilins etc for the first time in the model plant Brachypodium. Altogether, the present study provides new insights into structural characterization and evolution of pollen allergens and will further serve as a base for their

  14. Grasses as invasive plants in South Africa revisited: Patterns, pathways and management

    Directory of Open Access Journals (Sweden)

    Vernon Visser

    2017-03-01

    Full Text Available Background: In many countries around the world, the most damaging invasive plant species are grasses. However, the status of grass invasions in South Africa has not been documented recently. Objectives: To update Sue Milton’s 2004 review of grasses as invasive alien plants in South Africa, provide the first detailed species level inventory of alien grasses in South Africa and assess the invasion dynamics and management of the group. Method: We compiled the most comprehensive inventory of alien grasses in South Africa to date using recorded occurrences of alien grasses in the country from various literature and database sources. Using historical literature, we reviewed past efforts to introduce alien grasses into South Africa. We sourced information on the origins, uses, distributions and minimum residence times to investigate pathways and patterns of spatial extent. We identified alien grasses in South Africa that are having environmental and economic impacts and determined whether management options have been identified, and legislation created, for these species. Results: There are at least 256 alien grass species in the country, 37 of which have become invasive. Alien grass species richness increased most dramatically from the late 1800s to about 1940. Alien grass species that are not naturalised or invasive have much shorter residence times than those that have naturalised or become invasive. Most grasses were probably introduced for forage purposes, and a large number of alien grass species were trialled at pasture research stations. A large number of alien grass species in South Africa are of Eurasian origin, although more recent introductions include species from elsewhere in Africa and from Australasia. Alien grasses are most prevalent in the south-west of the country, and the Fynbos Biome has the most alien grasses and the most widespread species. We identified 11 species that have recorded environmental and economic impacts in the

  15. Seasonal variation of soluble carbohydrates and starch in Echinolaena inflexa, a native grass species from the Brazilian savanna, and in the invasive grass Melinis minutiflora Variações sazonais de carboidratos solúveis e amido em Echinolaena inflexa, uma espécie nativa do cerrado, e na gramínea invasora Melinis minutiflora

    Directory of Open Access Journals (Sweden)

    A. Souza

    2010-05-01

    Full Text Available Echinolaena inflexa (Poir. Chase is an abundant C3 grass species with high biomass production in the Brazilian savanna (cerrado; Melinis minutiflora Beauv. is an African C4 forage grass widespread in cerrado and probably displacing some native herbaceous species. In the present work, we analysed seasonally the content and composition of soluble carbohydrates, the starch amounts and the above-ground biomass (phytomass of E. inflexa and M. minutiflora plants harvested in two transects at 5 and 130 m from the border in a restrict area of cerrado at the Biological Reserve and Experimental Station of Mogi-Guaçu (SP, Brazil. Results showed that water soluble carbohydrates and starch amounts from the shoots of both species varied according to the time of the year, whilst in the underground organs, variations were observed mainly in relation to the transects. Marked differences in the pattern of the above-ground biomass production between these two grasses relative to their location in the Reserve were also observed, with two peaks of the invasive species (July and January at the Reserve border. The differences in carbohydrate accumulation, partitioning and composition of individual sugars concerning time of the year and location in the Reserve were more related to the annual growth cycle of both grasses and possibly to specific physiological responses of M. minutiflora to disturbed environments in the Reserve border.Echinolaena inflexa (Poir. Chase é uma gramínea C3 muito abundante em áreas de cerrado e com alta produção de biomassa. Melinis minutiflora Beauv. é uma gramínea C4 de origem africana introduzida no Brasil para fins forrageiros, que se espalhou amplamente por áreas de cerrado, provavelmente deslocando espécies nativas. No presente trabalho, o conteúdo e a composição de carboidratos solúveis, o teor de amido e a biomassa aérea foram analisados sazonalmente em plantas de E. inflexa e M. minutiflora coletadas em dois transectos

  16. Quantification in mass units of group 1 grass allergens by a monoclonal antibody-based sandwich ELISA.

    Science.gov (United States)

    Arilla, M C; Ibarrola, I; Eraso, E; Aguirre, M; Martínez, A; Asturias, J A

    2001-08-01

    Grass pollen extracts currently used for allergy diagnosis and immunotherapy are a complex mixture of proteins of which only a few have allergenic activity. Lol p 1 is one of the most important allergens in grass pollen extracts. To develop a two-site enzyme-linked immunosorbent assay for the quantification of Lol p 1 and other group 1 allergens from grass species, and to assess its suitability for quantifying this group of allergens. Balb/c mice immunized with recombinant Lol p 1 were used for the production of monoclonal antibodies. Screening of hybridomas was performed by direct ELISA, and selected monoclonal antibodies were immobilized on ELISA plates and incubated with samples containing group 1 allergens. Bound allergens were detected by a combination of biotinylated Lol p 1-specific monoclonal antibody and peroxidase-streptavidin conjugate. The assay is based on three Lol p 1-specific monoclonal antibodies with different epitope specificities. The optimized ELISA measured Lol p 1 concentrations ranging from 125 to 1000 ng/mL and could quantify group 1 allergen from grass species belonging to the Pooidea subfamily. The assay does not depend on anti-sera production or availability of human sera and thus reactives can be produced in unlimited amounts. This sensitive and specific Lol p 1 assay will be helpful both for quantifying the group 1 allergen content of Pooideae pollen extracts intended for clinical use and for studying cross-reactivities among pollen extracts.

  17. Local community, mobility and belonging

    DEFF Research Database (Denmark)

    Jørgensen, Anja; Arp Fallov, Mia; Knudsen, Lisbeth B.

    2011-01-01

    ,recent developments in the understandings of mobility and local communities,and presents different theoretical views on local belonging.These questions highlight the necessity to discuss and investigate two overall narratives in social theory about the connection between space and social relations.Namely,1...

  18. resistance of napier grass clones to napier grass stunt disease

    African Journals Online (AJOL)

    ACSS

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease. (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  19. Resistance of Napier grass clones to Napier grass Stunt Disease ...

    African Journals Online (AJOL)

    Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD.

  20. A new species of Eimeria Schneider, 1875 from the Serra dos Órgãos National Park, Rio de Janeiro, Brazil, with notes on its endogenous development in the montane grass mouse, Akodon montensis Thomas, 1913 (Rodentia: Sigmodontinae).

    Science.gov (United States)

    de Santana Miglionico, Marcos Tobias; Viana, Lúcio André; Barbosa, Helene Santos; Mota, Ester Maria; da Costa Neto, Sócrates Fraga; Frazão-Teixeira, Edwards; D'Andrea, Paulo Sergio

    2018-02-01

    A total of 53 specimens of the montane grass mouse, Akodon montensis Thomas, 1913 were collected in the Serra dos Órgãos National Park (SONP) in November 2014 and July 2015. The fecal material was analyzed, and a prevalence of 7.5% was recorded for a new coccidian species of the genus Eimeria Schneider, 1875, with part of its endogenous development recorded in the small intestine. The oocysts of a new coccidian species of genus Eimeria are ellipsoidal to subspherical. The wall is bi-layered, c. 1.5 μm (1.3-1.6 μm) thick, outer layer rough. Oocyst (n = 126) mean length is 25.3 μm (21.0-28.0 μm), with a width of 20.2 μm (17.0-22.0 μm) and mean length/width (L:W) ratio of 1.3 (1.2-1.4). Polar granule is present, with the oocyst residuum as a large spherical to subspherical globule. Sporocyst shape (n = 126) is ellipsoidal, with a mean length of 11.8 μm (9.3-14.4 μm), width of 7.9 μm (6.7-9.3 μm), and mean L:W ratio of 1.5 (1.4-1.7). Sporocysts with nipple-like Stieda body and sub-Stieda body are absent. A sporocyst residuum formed by several globules, usually along the sporocyst wall. This is the first record of Eimeria in the montane grass mouse from Brazil.

  1. Seed production and establishment of western Oregon native grasses

    Science.gov (United States)

    Dale C. Darris

    2005-01-01

    It is well understood that native grasses are ecologically important and provide numerous benefits. However, unfavorable economics, low seed yields for some species, genetic issues, and a lack of experience behind the production and establishment of most western Oregon native grasses remain significant impediments for their expanded use. By necessity, adaptation of...

  2. Identification of grazed grasses using epidermal characters | R ...

    African Journals Online (AJOL)

    The use of anatomical features of the abaxial epidermis of grasses is discussed for the identification of fragments of epidermis present in samples of rumen. The reliability of this technique, and the variation of the epidermal characters in two widely distributed species of grass, is given. A "Key" to identity certain genera of ...

  3. Transnational Connections and Multiple Belongings

    DEFF Research Database (Denmark)

    Galal, Lise Paulsen; Sparre, Sara Cathrine Lei

    With the purpose of presenting DIMECCE key findings, we in this paper present different aspects, potentials and challenges related to the Middle Eastern Christians transnational connections and multiple belonging. We distinguish between individual transnational connections and practices, such as ......, such as family relations, churches as transnational – or global – institutions, and other organisations and associations established to support politically, socially or culturally connections and development in the country or region of origin....

  4. Evaluating grasses as a long-term energy resource

    Energy Technology Data Exchange (ETDEWEB)

    Christian, D.G.; Riche, A.B.

    2001-07-01

    The work reported here is part of an ongoing project that aims to evaluate the yields of three perennial rhizomatous grasses and determine their suitability as bio-energy crops. The work began in 1993, and the grasses have been monitored continuously since that time. This report covers the period 1999/2000, and includes: the performance of plots of the energy grasses Miscanthus grass, switchgrass and reed canary grass seven years after they were planted; assessment of the yield of 15 genotypes of Miscanthus planted in 1997; monitoring all the species throughout the growing period for the presence of pests, weeds and diseases; measurement of the amount of nitrate leached from below Miscanthus grass; investigating the occurrence of lodging in switchgrass. (Author)

  5. Grass Rooting the System

    Science.gov (United States)

    Perlman, Janice E.

    1976-01-01

    Suggests a taxonomy of the grass roots movement and gives a general descriptive over view of the 60 groups studied with respect to origin, constituency, size, funding, issues, and ideology. (Author/AM)

  6. The carbon fertilization effect over a century of anthropogenic CO2 emissions: higher intracellular CO2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest.

    Science.gov (United States)

    Drake, Brandon L; Hanson, David T; Lowrey, Timothy K; Sharp, Zachary D

    2017-02-01

    From 1890 to 2015, anthropogenic carbon dioxide emissions have increased atmospheric CO 2 concentrations from 270 to 400 mol mol -1 . The effect of increased carbon emissions on plant growth and reproduction has been the subject of study of free-air CO 2 enrichment (FACE) experiments. These experiments have found (i) an increase in internal CO 2 partial pressure (c i ) alongside acclimation of photosynthetic capacity, (ii) variable decreases in stomatal conductance, and (iii) that increases in yield do not increase commensurate with CO 2 concentrations. Our data set, which includes a 115-year-long selection of grasses collected in New Mexico since 1892, is consistent with an increased c i as a response to historical CO 2 increase in the atmosphere, with invasive species showing the largest increase. Comparison with Palmer Drought Sensitivity Index (PDSI) for New Mexico indicates a moderate correlation with Δ 13 C (r 2  = 0.32, P < 0.01) before 1950, with no correlation (r 2  = 0.00, P = 0.91) after 1950. These results indicate that increased c i may have conferred some drought resistance to these grasses through increased availability of CO 2 in the event of reduced stomatal conductance in response to short-term water shortage. Comparison with C 3 trees from arid environments (Pinus longaeva and Pinus edulis in the US Southwest) as well as from wetter environments (Bromus and Poa grasses in New Mexico) suggests differing responses based on environment; arid environments in New Mexico see increased intrinsic water use efficiency (WUE) in response to historic elevated CO 2 while wetter environments see increased c i . This study suggests that (i) the observed increases in c i in FACE experiments are consistent with historical CO 2 increases and (ii) the CO 2 increase influences plant sensitivity to water shortage, through either increased WUE or c i in arid and wet environments, respectively. © 2016 John Wiley & Sons Ltd.

  7. Homogenous stands of a wetland grass harbour diverse consortia of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Wirsel, Stefan G R

    2004-05-01

    A molecular approach was applied to investigate the colonisation of arbuscular mycorrhizal fungi (AMF) on the wetland grass Phragmites australis. A PCR assay targeting the traditional families of the Glomeromycota yielded products that were used to construct libraries of 18S rDNA. Five hundred and forty six clones were typed by restriction analysis and 76 representatives were sequenced. The majority corresponded to a wide range of taxa within Glomus group A, a few belonged to the "Diversisporaceae" and none to the genera Scutellospora or Acaulospora. Among these sequences, some were very similar to those reported earlier, e.g. Glomus mosseae and G. fasciculatum, other pointed to various new taxa. Although this wetland habitat harboured just one single plant species, phylogenetic analysis exhibited 21 AMF phylotypes, which is in the same range as reported for other natural ecosystems composed of more diverse host communities. Diversity indices supported the perception that the AMF mycoflora associated with this natural grass "monoculture" is not depauperate as it had been described for grasses of crop monocultures. Soil conditions determined the mycorrhizal state of the host, since AMF were not detected at the lakeward front of the reed belt, which is permanently waterlogged.

  8. Controlling grass weeds on hard surfaces

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2012-01-01

    An experiment was conducted on a specially designed hard surface to study the impact of time interval between flaming treatments on the regrowth and flower production of two grass weeds. The goal of this experiment was to optimize the control of annual bluegrass and perennial ryegrass, both species...... that are very difficult to control without herbicides. Aboveground biomass from 72 plants per treatment was harvested and dry weights were recorded at regular intervals to investigate how the plants responded to flaming. Regrowth of the grasses was measured by harvesting aboveground biomass 2 wk after......, as they did not increase the reduction of aboveground biomass compared with the 7-d treatment interval. Knowledge on the regrowth of grass weeds after flaming treatments provided by this study can help improve recommendations given to road keepers and park managers for management on these weeds. Nomenclature...

  9. Matrix-assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS) as a Reliable Tool to Identify Species of Catalase-negative Gram-positive Cocci not Belonging to the Streptococcus Genus.

    Science.gov (United States)

    Almuzara, Marisa; Barberis, Claudia; Velázquez, Viviana Rojas; Ramirez, Maria Soledad; Famiglietti, Angela; Vay, Carlos

    2016-01-01

    To evaluate the performance of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) by using 190 Catalase-negative Gram-Positive Cocci (GPC) clinical isolates. All isolates were identified by conventional phenotypic tests following the proposed scheme by Ruoff and Christensen and MALDI-TOF MS (Bruker Daltonics, BD, Bremen, Germany). Two different extraction methods (direct transfer formic acid method on spot and ethanol formic acid extraction method) and different cut-offs for genus/specie level identification were used. The score cut-offs recommended by the manufacturer (≥ 2.000 for species-level, 1.700 to 1.999 for genus level and genus level, ≥ 1.700 for species-level and score genus or species. MALDI-TOF MS identification was considered correct when the result obtained from MS database agreed with the phenotypic identification result. When both methods gave discordant results, the 16S rDNA or sodA genes sequencing was considered as the gold standard identification method. The results obtained by MS concordant with genes sequencing, although discordant with conventional phenotyping, were considered correct. MS results discordant with 16S or sod A identification were considered incorrect. Using the score cut-offs recommended by the manufacturer, 97.37% and 81.05% were correctly identified to genus and species level, respectively. On the other hand, using lower cut-off scores for identification, 97.89% and 94.21% isolates were correctly identified to genus and species level respectively by MALDI-TOF MS and no significant differences between the results obtained with two extraction methods were obtained. The results obtained suggest that MALDI-TOF MS has the potential of being an accurate tool for Catalase-negative GPC identification even for those species with difficult diagnosis as Helcococcus , Abiotrophia , Granulicatella , among others. Nevertheless, expansion of the library, especially including more strains with

  10. Brassinosteroid Mediated Cell Wall Remodeling in Grasses under Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Xiaolan Rao

    2017-05-01

    Full Text Available Unlike animals, plants, being sessile, cannot escape from exposure to severe abiotic stresses such as extreme temperature and water deficit. The dynamic structure of plant cell wall enables them to undergo compensatory changes, as well as maintain physical strength, with changing environments. Plant hormones known as brassinosteroids (BRs play a key role in determining cell wall expansion during stress responses. Cell wall deposition differs between grasses (Poaceae and dicots. Grass species include many important food, fiber, and biofuel crops. In this article, we focus on recent advances in BR-regulated cell wall biosynthesis and remodeling in response to stresses, comparing our understanding of the mechanisms in grass species with those in the more studied dicots. A more comprehensive understanding of BR-mediated changes in cell wall integrity in grass species will benefit the development of genetic tools to improve crop productivity, fiber quality and plant biomass recalcitrance.

  11. 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.

  12. The inventory of mollusc species and its potent on seagrass bed in Kei Kecil Islands, Southeast Moluccas

    Directory of Open Access Journals (Sweden)

    AGUS KUSNADI

    2008-10-01

    Full Text Available Inventory of mollusk species and its potential on sea grass bed in Kei Kecil islands, Southeast Moluccas have been conducted by using quadrate-transect line method. The study was carried out in February-August 2007. There were 103 species of mollusk observed, 80 species belong to gastropods and 23 belong to bivalves. From the total species, 72 of them were reported as the potential species and the others still unknown. Most of potential group was used as food resources (55 species and other species were potential as decoration, souvenir, ornament, and accessories (31 species. Some species were potential for building material, knife tool, barter tool and bioactive compounds. The top shells (Trochus niloticus, the giant clams (Tridacna spp. and Hippopus hippopus and the abalone (Haliotis spp. were the major trading commodities for shellfish fisheries.

  13. A new species of Stenodiplosis (Diptera: Cecidomyiidae) on Spartina grasses (Poaceae) with notes on its biology and its parasitoid Tetrastichus bromi (Hymenoptera: Eulophidae).

    Science.gov (United States)

    López, J Manuel Perilla; Johnson, Paul J; Gagné, Raymond J; Boe, Arvid

    2015-12-09

    Stenodiplosis spartinae Gagné new species (Diptera: Cecidomyiidae) is described from eastern South Dakota and coastal North Carolina, and compared with other American congeners. The known host plants are Spartina alterniflora and S. pectinata. The larva is a seed predator of the ovule and immature caryopsis of the host plant. Adult activity is from the early emergence of the host inflorescence through anthesis. Oviposition occurs in the floret with eggs laid under the edges of the palea and lemma. The larva apparently overwinters in dehisced spikelets in the soil among rhizomes of S. pectinata, with pupation in late spring. Laboratory emergence and field activity of the adults suggest a potentialsecond or third generation developing on late emerging inflorescences. Larval feeding does not induce external color or shape changes in the spikelet. Apparently all three instars are ectoparasitized by Tetrastichus bromi Kostyukov (Hymenoptera: Eulophidae) that was probably introduced to North America in the late 1800's and is inculcated into parasitoid guilds of several Stenodiplosis species. Resource partitioning appears to occur between the gall midge and early instars of Aethes spartinana Barnes and McDunnough (Lepidoptera: Tortricidae) that feed on maturing caryopses. The feeding of this gall midge and the moth probably account for most of the reduced seed production in both natural and agronomic populations of S. pectinata.

  14. Establishing native warm season grasses on Eastern Kentucky strip mines

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, T.G.; Larkin, J.L.; Arnett, M.B. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Forestry

    1998-12-31

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.

  15. Establishing native warm season grasses on Eastern Kentucky strip mines

    International Nuclear Information System (INIS)

    Barnes, T.G.; Larkin, J.L.; Arnett, M.B.

    1998-01-01

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat

  16. Identification of the sex-determining locus in grass puffer (Takifugu niphobles) provides evidence for sex-chromosome turnover in a subset of Takifugu species

    Science.gov (United States)

    Atsumi, Kazufumi; Kamiya, Takashi; Nozawa, Aoi; Aoki, Yuma; Tasumi, Satoshi; Koyama, Takashi; Nakamura, Osamu; Suzuki, Yuzuru

    2018-01-01

    There is increasing evidence for frequent turnover in sex chromosomes in vertebrates. Yet experimental systems suitable for tracing the detailed process of turnover are rare. In theory, homologous turnover is possible if the new sex-determining locus is established on the existing sex-chromosome. However, there is no empirical evidence for such an event. The genus Takifugu includes fugu (Takifugu rubripes) and its two closely-related species whose sex is most likely determined by a SNP at the Amhr2 locus. In these species, males are heterozygous, with G and C alleles at the SNP site, while females are homozygous for the C allele. To determine if a shift in the sex-determining locus occurred in another member of this genus, we used genetic mapping to characterize the sex-chromosome systems of Takifugu niphobles. We found that the G allele of Amhr2 is absent in T. niphobles. Nevertheless, our initial mapping suggests a linkage between the phenotypic sex and the chromosome 19, which harbors the Amhr2 locus. Subsequent high-resolution analysis using a sex-reversed fish demonstrated that the sex-determining locus maps to the proximal end of chromosome 19, far from the Amhr2 locus. Thus, it is likely that homologous turnover involving these species has occurred. The data also showed that there is a male-specific reduction of recombination around the sex-determining locus. Nevertheless, no evidence for sex-chromosome differentiation was detected: the reduced recombination depended on phenotypic sex rather than genotypic sex; no X- or Y-specific maker was obtained; the YY individual was viable. Furthermore, fine-scale mapping narrowed down the new sex-determining locus to the interval corresponding to approximately 300-kb of sequence in the fugu genome. Thus, T. niphobles is determined to have a young and small sex-determining region that is suitable for studying an early phase of sex-chromosome evolution and the mechanisms underlying turnover of sex chromosome. PMID

  17. Grass-on-grass competition along a catenal gradient in mesic ...

    African Journals Online (AJOL)

    Three aboveground treatments (full light competition, no light competition and clipping to simulate grazing), and two belowground treatments (full belowground competition and belowground competition excluded by a root tube), were used. On all soil depths the three grass species differed in mean mass, with E. racemosa ...

  18. 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.

  19. The effects of energy grass plantations on biodiversity

    International Nuclear Information System (INIS)

    Semere, T.; Slater, F.

    2005-01-01

    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

  20. BEHAVIOR ANALYSIS OF TREE LEGUME SPECIES INTRODUCED IN TROPICAL GRASS PASTURES ANÁLISE DO COMPORTAMENTO DE ESPÉCIES LEGUMINOSAS ARBÓREAS INTRODUZIDAS EM PASTAGENS DE GRAMÍNEAS TROPICAIS

    Directory of Open Access Journals (Sweden)

    Janaina Ribeiro Costa

    2007-09-01

    Full Text Available

    The objective of this study was to analyze the behavior of sixteen tree legume species introduced in tropical grass pastures, without seedling protection and in the presence of animals, in three municipalities of Rio de Janeiro State, Brazil. A multivariate factor analysis method was used with sixteen variables related to seven experimental units in the municipalities and ten variables related to leguminous species. The first rotative factor (F1, which explained the highest percentage of the observed variance (62.7%, showed that the Fazenda Santo Antônio experimental unit, in the Itatiaia municipality, presented the highest values for Ca+Mg, N, and Mg, and the lowest value for P (soil sample collected at the beginning of experimental period, while the opposite was observed for Sipa I unit, in the Seropédica municipality. The F1 factor also showed that the species Jurema branca (Mimosa artemisiana and Jurema preta (Mimosa tenuiflora presented the highest values for diameter growth rate of stem and crown, and the lowest percentage of pastured seedlings, while Leucena (Leucaena leucocephala showed the inverse behavior. Results indicate that M. artemisiana and M. tenuiflora present better potential for introduction in tropical grass pastures without seedling protection and without animal exclusion.

    KEY-WORDS: Tree seedling; factor analysis; communality, mimosa; Leucaena.

    O objetivo deste trabalho foi analisar o comportamento de dezesseis espécies leguminosas arbóreas introduzidas em pastagens de gramíneas tropicais, sem proteção das mudas e na presença de animais, em três municípios do estado do Rio de Janeiro. Para isso, utilizou-se a técnica multivariada da análise de fatores, considerando-se dezesseis variáveis relativas a sete unidades experimentais nos municípios e dez vari

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

    OpenAIRE

    Thomas Serensits; Matthew Cutulle; Jeffrey F. Derr

    2011-01-01

    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 di...

  2. Effects of feeding dairy cows different legume-grass silages on milk phytoestrogen concentration

    DEFF Research Database (Denmark)

    Höjer, A; Adler, S; Purup, Stig

    2012-01-01

    interval of legume-grass silage on phytoestrogen intake and milk phytoestrogen concentrations. In one experiment, 15 Swedish Red dairy cows were fed 2- or 3-cut red clover-grass silage, or 2-cut birdsfoot trefoil-grass silage. In a second experiment, 16 Norwegian Red dairy cows were fed short-term ley...... red clover-grass silage diet (1,494μg/kg of milk). Because of the metabolism of biochanin A, genistein, and prunetin, their concentrations in milk and the apparent recovery were low. Coumestrol was detected in only short-term and long-term ley silage mixtures, and its milk concentration was low....... Concentrations of secoisolariciresinol and matairesinol were higher in 2-cut birdsfoot trefoil-grass and long-term ley silage mixtures, those with legume species other than red clover, and the highest grass proportions. The 2-cut birdsfoot trefoil-grass silage diet also resulted in higher enterolactone...

  3. Evapotranspiration and water use efficiency of different grass ...

    African Journals Online (AJOL)

    Evapotranspiration (Et) and water use efficiency (WUE) were determined for each of seven grass species during the 1986/87 seasons. The highest and lowest mean daily Et of 2, 39 and 1, 66 mm were recorded respectively for Themeda triandra and Sporobolus fimbriatus. Between species, the average Et for the two ...

  4. A new grass frog from Namibia | Channing | African Zoology

    African Journals Online (AJOL)

    A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that ...

  5. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Ørby, Pia Viuf; Skjøth, Carsten Ambelas

    2014-01-01

    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......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...... 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...

  6. The Belonging to the University Scale

    Science.gov (United States)

    Karaman, Omer; Cirak, Yuksel

    2017-01-01

    The aim of the study is to develop a belonging to the university scale (BUS) in order to determine the level of fulfillment of the need to belong among university students at the higher education institutions they attend. The population of the investigation includes university students studying at the campus of Ordu University. A 5 point…

  7. Social Inclusion and Local Practices of Belonging

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2009-09-01

    Full Text Available Social inclusion has been conceptualised as having two key aspects: distributional aspects relating to access to resources including employment, and relational aspects which concern the connections between people and the wider society. While both are important, the emphasis in Australian social inclusion policy has been on distributional aspects. This paper focuses on the relational aspects of social inclusion, and argues that it is critically important to include relational considerations in social inclusion policy. Central to the relational aspects of social inclusion is achieving a sense of belonging, particularly at the everyday, local level. Belonging in this everyday sense can be thought of as an ongoing project achieved through everyday practices, rather than solely in terms of membership of a group. While many such practices, for example regularly engaging in team sports, are accepted ways of establishing and maintaining belonging, for others in a community practices of belonging may necessitate disrupting or at least broadening the established norms of how one belongs. To ground this discussion of inclusion and belonging, this paper draws on practices of belonging in a regional community. Established norms of belonging are examined through the idea of ‘being a local’, a way of belonging that appears to be based on membership. The paper then turns to two local projects which disrupt the exclusive bounds of local membership and establish new and inclusive practices of belonging. To conclude, parallels are drawn between the boundaries which define ‘the social’ in social inclusion and ‘the local community’ in being a local, to argue for the importance of including relational aspects of social inclusion within social inclusion policy debates and program formulation.

  8. 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...

  9. Comparative growth analysis of cool- and warm-season grasses in a cool-temperate environment

    International Nuclear Information System (INIS)

    Belesky, D.P.; Fedders, J.M.

    1995-01-01

    Using both cool-season (C3) and warm-season (C4) species is a viable means of optimizing herbage productivity over varying climatic conditions in temperate environments. Despite well-documented differences in water, N, and radiation use, no consistent evidence demonstrates productivity differences among C3 and C4 perennial grass species under identical management. A field study was conducted to determine relative growth rates (RGR), nitrogen productivity (NP), and mean radiation productivity (RP) (dry matter production as a function of incident radiation) of cool- and warm-season grasses managed identically. Results were used to identify management practices thd could lead to optimal productivity in combinations or mixtures of cool- and warm-season grasses. Dry matter yields of warm-season grasses equaled or surpassed those of cool-season grasses, despite a 40% shorter growth interval. Certain cool- and warm-season grasses appear to be suitable for use in mixtures, based on distribution of herbage production; however, actual compatibility may be altered by defoliation management. Relative growth rates varied among years and were about 40% lower for canopies clipped to a 10-cm residue height each time 20-cm of growth accumulated compared with other treatments. The RGR of warm-season grasses was twice that of cool-season grasses Nitrogen productivity (g DM g-1 N d -1) and mean radiation productivity (g DM MJ-1) for warm-season grasses was also more than twice that of cool-season grasses. Radiation productivity of cool-season grasses was dependent on N, while this was not always the case for warm-season grasses. The superior production capability of certain warm-season compared with cool-season grasses in a cool-temperate environment can be sustained under a range of defoliation treatments and demonstrates suitability for use in frequently defoliated situations

  10. Extending juvenility in grasses

    Energy Technology Data Exchange (ETDEWEB)

    Kaeppler, Shawn; de Leon Gatti, Natalia; Foerster, Jillian

    2017-04-11

    The present invention relates to compositions and methods for modulating the juvenile to adult developmental growth transition in plants, such as grasses (e.g. maize). In particular, the invention provides methods for enhancing agronomic properties in plants by modulating expression of GRMZM2G362718, GRMZM2G096016, or homologs thereof. Modulation of expression of one or more additional genes which affect juvenile to adult developmental growth transition such as Glossy15 or Cg1, in conjunction with such modulation of expression is also contemplated. Nucleic acid constructs for down-regulation of GRMZM2G362718 and/or GRMZM2G096016 are also contemplated, as are transgenic plants and products produced there from, that demonstrate altered, such as extended juvenile growth, and display associated phenotypes such as enhanced yield, improved digestibility, and increased disease resistance. Plants described herein may be used, for example, as improved forage or feed crops or in biofuel production.

  11. Changes in salt-marsh carabid assemblages after an invasion by the native grass Elymus athericus (Link Kerguélen

    Directory of Open Access Journals (Sweden)

    Anita Georges

    2011-05-01

    Full Text Available As a result of an invasion by the native grass Elymus athericus (Link Kerguélen (Poaceae in the last 10 years, a major change in vegetation cover has occurred in salt marshes of the Mont Saint-Michel bay, Western France. The impact of such an invasion on carabid assemblages, a dominant group of terrestrial arthropods in these habitats and containing several stenotopic species, is investigated here. In our study site, carabid data are available from 1983 and 1984, allowing a comparison of species distribution ranges in salt marshes before (1983–1984 and after (2002 the E. athericus invasion. A total of 16,867 adults belonging to 40 species were caught. By considering the presence-absence of species shared between studies, we show that the invasion by E. athericus promoted the progression of non-coastal species (mainly Pterostichus s.l. spp.. This did however not interfere with resident species distributions, finally resulting in higher carabid species richness in the entire area. The species composition and abundances of carabid assemblages were also compared between natural and invaded stations in 2002. The main result is that abundances of some halophilic species decreased in one invaded plot (in case of Pogonus chalceus (Marsham 1802 whereas the opposite pattern was observed for other species (e.g., Bembidion minimum (Fabricius 1792. Invaded habitats were characterized by lower percentages of halophilic species and higher total species richness.

  12. Dose-response relationship of a new Timothy grass pollen allergoid in comparison with a 6-grass pollen allergoid.

    Science.gov (United States)

    Pfaar, O; Hohlfeld, J M; Al-Kadah, B; Hauswald, B; Homey, B; Hunzelmann, N; Schliemann, S; Velling, P; Worm, M; Klimek, L

    2017-11-01

    Subcutaneous allergen immunotherapy with grass pollen allergoids has been proven to be effective and safe in the treatment of patients with allergic rhinoconjunctivitis. Based on the extensive cross-reactivity among Pooideae species, it has been suggested that grass pollen extracts could be prepared from a single species, rather than from a multiple species mixture. To find the optimal dose of a Phleum pratense (P. pratense) allergoid preparation and compare its efficacy and safety to a 6-grass pollen allergoid preparation. In this double-blind, placebo-controlled study (EudraCT: 2011-000674-58), three doses of P. pratense allergoid (1800 therapeutic units (TU), standard-dose 6000 TU and 18 000 TU) were compared with placebo and the marketed 6-grass pollen allergoid (6000 TU). In a pre-seasonal dosing regimen, 102 patients were randomized to five treatment groups and received nine subcutaneous injections. The primary efficacy endpoint was the change in weal size (late-phase reaction [LPR]) in response to the intracutaneous testing (ICT) before and after treatment, comparing the active allergoids to placebo. Secondary outcomes were the change in Total Nasal Symptom Score (TNSS) assessed in the allergen exposure chamber (AEC), the changes in P. pratense-serum-specific IgG 4 and the incidence of adverse events (AEs). All three doses of the P. pratense and the 6-grass pollen allergoid preparations were significantly superior to placebo for the primary outcome, whereas there were no significant differences in the change in TNSS. Compared to the standard-dose, the high-dose of P. pratense did not produce any additional significant benefit, but showed a slight increase in AEs. Yet this increase in AEs was lower than for the 6-grass pollen preparation. The standard-dose of the new P. pratense allergoid was comparable to the marketed 6-grass pollen preparation at equal dose for the parameters measured. © 2017 The Authors. Clinical & Experimental Allergy Published by John

  13. Taxonomic studies of grasses and their indigenous uses in the salt ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... countries like United States, the principal sources of meat ... Many species of native and introduced grasses are utilized in improved ... turning northwest to cross the river Indus near Kalabagh. (Ahmad and ... Key to the identification of grasses of Salt Range of Pakistan. S. No ...... Under shade of trees.

  14. Improved quality of beneath-canopy grass in South African savannas: Local and seasonal variation

    NARCIS (Netherlands)

    Treydte, A.C.; Looringh van Beeck, F.A.; Ludwig, F.; Heitkonig, I.M.A.

    2008-01-01

    Questions: Do large trees improve the nutrient content and the structure of the grass layer in savannas? Does the magnitude of this improvement differ with locality ( soil nutrients) and season ( water availability)? Are grass structure and species composition beneath tree canopies influenced by

  15. Effect of short-duration overnight cattle kraaling on grass production ...

    African Journals Online (AJOL)

    ... grass species, such as Urochloa mosambicensis and Panicum maximum, were more abundant in abandoned kraal sites than the surrounding vegetation. We conclude that shortduration overnight cattle kraaling improves grass quality and biomass. Keywords: biomass, crude protein, diversity, fibre, nutrient hotspots ...

  16. On the number of genes controlling the grass stage in longleaf pine

    Science.gov (United States)

    C. Dana Nelson; C. Weng; Thomas L. Kubisiak; M. Stine; C.L. Brown

    2003-01-01

    The grass stage is an inherent and distinctive developmental trait of longleaf pine (Pinus palustris), in which height growth in the first few years after germination is suppressed. In operational forestry practice the grass stage extends for nvo to several years and often plays a role in planting failures and decisions to plant alternative species....

  17. FUEL CONDITIONS ASSOCIATED WITH NATIVE AND EXOTIC GRASSES IN A SUBTROPICAL DRY FOREST IN PUERTO RICO

    Science.gov (United States)

    Jarrod M. Thaxton; Skip J. Van Bloem; Stefanie Whitmire

    2012-01-01

    Exotic grasses capable of increasing frequency and intensity of anthropogenic fire have invaded subtropical and tropical dry forests worldwide. Since many dry forest trees are susceptible to fire, this can result in decline of native species and loss of forest cover. While the contribution of exotic grasses to altered fire regimes has been well documented, the role of...

  18. Status and use of important native grasses adapted to sagebrush communities

    Science.gov (United States)

    Thomas A. Jones; Steven R. Larson

    2005-01-01

    Due to the emphasis on restoration, native cool-season grass species are increasing in importance in the commercial seed trade in the Western U.S. Cultivated seed production of these native grasses has often been hampered by seed dormancy, seed shattering, and pernicious awns that are advantageous outside of cultivation. Relatively low seed yields and poor seedling...

  19. Ensiling as pretreatment of grass for lignocellulosic biomass conversion

    DEFF Research Database (Denmark)

    Ambye-Jensen, Morten

    for subsequent enzymatic saccharification of cellulose and hemicellulose, by using the temperate grass Festulolium Hykor. The method was additionally combined with hydrothermal treatment, in order to decrease the required severity of an industrial applied pretreatment method. The first part of the project...... conditions providing the best possible pretreatment effect. The parameters were biomass composition, varied by ensiling of four seasonal cuts of grass, different dry matter (DM) content at ensiling, and an addition of different lactic acid bacteria species. First of all, the study confirmed that ensiling can...... act as a method of pretreatment and improve the enzymatic cellulose convertibility of grass. Furthermore, low DM ensiling was found to improve the effects of pretreatment due to a higher production of organic acids in the silage. The effect of applied lactic acid bacteria species was, however...

  20. Early inflorescence development in the grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Kellogg

    2013-07-01

    Full Text Available The shoot apical meristem of grasses produces the primary branches of the inflorescence, controlling inflorescence architecture and hence seed production. Whereas leaves are produced in a distichous pattern, with the primordia separated from each other by an angle of 180o, inflorescence branches are produced in a spiral in most species. The morphology and developmental genetics of the shift in phyllotaxis have been studied extensively in maize and rice. However, in wheat, Brachypodium, and oats, all in the grass subfamily Pooideae, the change in phyllotaxis does not occur; primary inflorescence branches are produced distichously. It is unknown whether the distichous inflorescence originated at the base of Pooideae, or whether it appeared several times independently. In this study, we show that Brachyelytrum, the genus sister to all other Pooideae has spiral phyllotaxis in the inflorescence, but that in the remaining 3000+ species of Pooideae, the phyllotaxis is two-ranked. These two-ranked inflorescences are not perfectly symmetrical, and have a clear front and back; this developmental axis has never been described in the literature and it is unclear what establishes its polarity. Strictly distichous inflorescences appear somewhat later in the evolution of the subfamily. Two-ranked inflorescences also appear in a few grass outgroups and sporadically elsewhere in the family, but unlike in Pooideae do not generally correlate with a major radiation of species. After production of branches, the inflorescence meristem may be converted to a spikelet meristem or may simply abort; this developmental decision appears to be independent of the branching pattern.

  1. 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.

  2. 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.

  3. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

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

    2012-01-01

    , 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...... 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...

  4. 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.

  5. DESIGN OF GRASS BRIQUETTE MACHINE

    African Journals Online (AJOL)

    user

    E-mail addresses: 1 mike.ajieh@gmail.com, 2 dracigboanugo@yahoo.com, ... machine design was considered for processing biomass of grass origin. The machine operations include pulverization, compaction and extrusion of the briquettes.

  6. 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 ...

  7. A novel method to characterize silica bodies in grasses.

    Science.gov (United States)

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

    2016-01-01

    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. We developed a method utilizing the autofluorescence of silica bodies to investigate their size and distribution, along with the number of carbon inclusions within the silica bodies of perennial grass species Koeleria macrantha. Fluorescence images were analyzed by image software Adobe Photoshop CS5 or ImageJ that remarkably facilitated the quantification of silica bodies in the dry ash. We observed three types of silica bodies or silica body related mineral structures. Silica bodies were detected on both abaxial and adaxial epidermis of K. macrantha leaves, although their sizes, density, and distribution patterns were different. No auto-fluorescence was detected from carbon inclusions. The combination of fluorescence microscopy and image processing software displayed efficient utilization in the identification and quantification of silica bodies in K. macrantha leaf tissues, which should applicable to biological, ecological and geological studies of grasses including forage, turf grasses and cereal crops.

  8. The parasites of cereal stem borers (Lepidoptera: Cossidae, Crambidae, Noctuidae, Pyralidae) in Africa, belonging to the family Braconidae (Hymenoptera: Ichneumonoidea)

    NARCIS (Netherlands)

    Achterberg, van C.; Polaszek, A.

    1996-01-01

    A review is given of the parasites (parasitoids) of the African cereal stem borers (including introduced species) belonging to the family Braconidae (Hymenoptera); 38 species belonging to 19 genera are keyed and treated. Three new species are described: Macrocentrus sesamivorus spec. nov. from

  9. High green fodder yielding new grass varieties

    OpenAIRE

    C. Babu, K. Iyanar and A. Kalamani

    2014-01-01

    Two high biomass yielding forage grass varieties one each in Cumbu Napier hybrid and Guinea grass have been evolved at the Department of Forage Crops, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore and identified for release at national (All India) level as Cumbu Napier hybrid grass CO (BN) 5 and Guinea grass CO (GG) 3 during 2012 and 2013 respectively. Cumbu Napier hybrid grass CO (BN) 5 secured first rank at all national level with reference to green ...

  10. Non-native grass removal and shade increase soil moisture and seedling performance during Hawaiian dry forest restoration

    Science.gov (United States)

    Jared M. Thaxton; Susan Cordell; Robert J. Cabin; Darren R. Sandquist

    2012-01-01

    Invasive non-native species can create especially problematic restoration barriers in subtropical and tropical dry forests. Native dry forests in Hawaii presently cover less than 10% of their original area. Many sites that historically supported dry forest are now completely dominated by non-native species, particularly grasses. Within a grass-dominated site in leeward...

  11. How far can we simplify in vitro diagnostics for grass pollen allergy?: A study with 17 whole pollen extracts and purified natural and recombinant major allergens

    NARCIS (Netherlands)

    van Ree, R.; van Leeuwen, W. A.; Aalberse, R. C.

    1998-01-01

    BACKGROUND: Current diagnostics for grass pollen allergy are composed of mixtures of pollen of different grass species. Their complex composition hampers accurate standardization. OBJECTIVE: The aim of the study was to investigate whether mixtures of grass pollen extracts can be replaced by a single

  12. Effects of soil microorganisms on uptake of 89Sr by ryegrass and bahia grass

    International Nuclear Information System (INIS)

    Zhong Weiliang; Liu Kexing

    2006-01-01

    In present study, 60 Co γ-rays was used to irradiate soil with doses of 3.0 kGy and 25.0 kGy, respectively, to discriminate between arbuscular mycorrhizal (AM) fungi and other soil microorganisms, while soil without irradiation was used as control to study the effects of soil microorganisms on uptake of 89 Sr by ryegrass and bahia grass. The results showed that the AM infection rates in ryegrass and bahia grass were 48.0% and 28.0% in the control soil, respectively which indicated that both grass species were prone to forming AM symbiosis with AM fungi. Although AM fungi and other soil microorganisms had no significant effect on above ground biomass in ryegrass and bahia grass, both AM fungi and other soil microorganisms decreased the uptake of 89 Sr in the two grass species, though to a more or less extant. (authors)

  13. Study of Plant Species Composition of Grasslands in Mugla Village Region (Western Rhodopes, South Bulgaria

    Directory of Open Access Journals (Sweden)

    Plamen S. Stoyanov

    2016-06-01

    Full Text Available The study presents data on the diversity of grass species in the region of the village of Mugla (the Western Rhodopes. One hundred forty-one species of higher plants belonging to 40families were registered. (Apiaceae, Aspleniaceae, Asteraceae, Boraginaceae, Brassicaceae,Campanulaceae, Caryophyllaceae, Cistaceae, Cyperaceae, Dipsacaceae, Equisetaceae, Ericaceae,Euphorbiaceae, Fabaceae, Gentianaceae, Geraniaceae, Gesneriaceae, Hypericaceae, Juncaceae,Lamiaceae, Lemnaceae, Liliaceae, Linaceae, Menyanthaceae, Oleacea, Onagraceae, Orchidaceae,Parnassiaceae, Plantaginaceae, Plumbaginaceae, Poaceae, Polygalaceae, Primulaceae,Ranunculaceae, Rosaceae, Rubiaceae, Saxifragaceae, Scrophulariaceae, Valerianaceae andViolaceae. Their conservation status was presented, as well as medicinal plants.

  14. Belonging and Unbelonging from an Intersectional Perspective

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte

    2009-01-01

    lives and local communities. The three levels are explained and illustrated with empirical examples from a Nordic context, all based on the perspective of intersectionality between gender, class, race, and ethnicity. Finally, the article discusses some challenges for further research on belonging...

  15. Refugee youth, belonging and community sport

    NARCIS (Netherlands)

    Spaaij, R.

    2015-01-01

    This article examines community sport as a site where refugee youth negotiate belonging, which is conceptualised as a dynamic dialectic of ‘seeking’ and ‘granting’. Drawing on three years of ethnographic fieldwork among Somali Australian youth at community football (soccer) clubs in Melbourne, the

  16. Evaluation of six candidate DNA barcode loci for identification of five important invasive grasses in eastern Australia.

    Directory of Open Access Journals (Sweden)

    Aisuo Wang

    Full Text Available Invasive grass weeds reduce farm productivity, threaten biodiversity, and increase weed control costs. Identification of invasive grasses from native grasses has generally relied on the morphological examination of grass floral material. DNA barcoding may provide an alternative means to identify co-occurring native and invasive grasses, particularly during early growth stages when floral characters are unavailable for analysis. However, there are no universal loci available for grass barcoding. We herein evaluated the utility of six candidate loci (atpF intron, matK, ndhK-ndhC, psbE-petL, ETS and ITS for barcode identification of several economically important invasive grass species frequently found among native grasses in eastern Australia. We evaluated these loci in 66 specimens representing five invasive grass species (Chloris gayana, Eragrostis curvula, Hyparrhenia hirta, Nassella neesiana, Nassella trichotoma and seven native grass species. Our results indicated that, while no single locus can be universally used as a DNA barcode for distinguishing the grass species examined in this study, two plastid loci (atpF and matK showed good distinguishing power to separate most of the taxa examined, and could be used as a dual locus to distinguish several of the invasive from the native species. Low PCR success rates were evidenced among two nuclear loci (ETS and ITS, and few species were amplified at these loci, however ETS was able to genetically distinguish the two important invasive Nassella species. Multiple loci analyses also suggested that ETS played a crucial role in allowing identification of the two Nassella species in the multiple loci combinations.

  17. Climate change and the invasion of California by grasses

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Dangremond, Emily

    2012-01-01

    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...

  18. Additions to the grasses (Poaceae of Telangana from Kawal Tiger Reserve, Adilabad District, India

    Directory of Open Access Journals (Sweden)

    Alok Chorghe

    2015-07-01

    Full Text Available Three species of grasses viz., Dimeria orissae, Iseilema holei and Spodiopogon rhizophorus are being reported for the first time as new distributional records to Telangana from the Kawal Tiger Reserve. Detailed description and illustrations are provided here.

  19. How much gas can we get from grass?

    International Nuclear Information System (INIS)

    Nizami, A.S.; Orozco, A.; Groom, E.; Dieterich, B.; Murphy, J.D.

    2012-01-01

    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 CH 4 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 CH 4 kg −1 VS added over a 50 day retention period. ► A two phase system achieved 341 L CH 4 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 CH 4 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 CH 4 kg −1 VS added over a 50 day retention period. The SLBR–UASB achieved 341 L CH 4 kg −1 VS added at a 30 day retention time.

  20. Anaerobic co-digestion of sewage sludge with shredded grass from public green spaces.

    Science.gov (United States)

    Hidaka, Taira; Arai, Sayuri; Okamoto, Seiichiro; Uchida, Tsutomu

    2013-02-01

    Adding greenery from public spaces to the co-digestion process with sewage sludge was evaluated by shredding experiments and laboratory-scale batch and continuous mesophilic anaerobic fermentation experiments. The ratio of the shredded grass with 20mm or less in length by a commercially available shredder was 93%. The methane production was around 0.2NL/gVS-grass in the batch experiment. The continuous experiment fed with sewage sludge and shredded grass was stably operated for 81days. The average methane production was 0.09NL/gVS-grass when the TS ratio of the sewage sludge and the grass was 10:1. This value was smaller than those of other reports using grass silage, but the grass species in this study were not managed, and the collected grass was just shredded and not ensiled before feeding to the reactor for simple operation. The addition of grass to a digester can improve the carbon/nitrogen ratio, methane production and dewaterability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Interrogating "Belonging" in Belonging, Being and Becoming: The Early Years Learning Framework for Australia

    Science.gov (United States)

    Sumsion, Jennifer; Wong, Sandie

    2011-01-01

    In this article, the authors interrogate the use of "belonging" in "Belonging, Being and Becoming: the Early Years Learning Framework for Australia" (EYLF), Australia's first national curriculum for early childhood education and care settings and, from the authors' interrogation, possibilities are offered for thinking about and…

  2. Sonoran Desert ecosystem transformation by a C4 grass without the grass/fire cycle

    Science.gov (United States)

    Olsson, Aaryn D.; Betancourt, Julio; McClaran, Mitchel P.; Marsh, Stuart E.

    2012-01-01

    Aim Biological invasions facilitate ecosystem transformation by altering the structure and function, diversity, dominance and disturbance regimes. A classic case is the grass–fire cycle in which grass invasion increases the frequency, scale and/or intensity of wildfires and promotes the continued invasion of invasive grasses. Despite wide acceptance of the grass–fire cycle, questions linger about the relative roles that interspecific plant competition and fire play in ecosystem transformations. Location Sonoran Desert Arizona Upland of the Santa Catalina Mountains, Arizona, USA. Methods We measured species cover, density and saguaro (Carnegiea gigantea) size structure along gradients of Pennisetum ciliare invasion at 10 unburned/ungrazed P. ciliare patches. Regression models quantified differences in diversity, cover and density with respect to P. ciliare cover, and residence time and a Fisher's exact test detected demographic changes in saguaro populations. Because P. ciliare may have initially invaded locations that were both more invasible and less diverse, we ran analyses with and without the plots in which initial infestations were located. Results Richness and diversity decreased with P. ciliare cover as did cover and density of most dominant species. Richness and diversity declined with increasing time since invasion, suggesting an ongoing transformation. The proportion of old-to-young Carnegiea gigantea was significantly lower in plots with dominant P. ciliare cover. Main conclusions Rich desert scrub (15–25 species per plot) was transformed into depauperate grassland (2–5 species per plot) within 20 years following P. ciliare invasion without changes to the fire regime. While the onset of a grass–fire cycle may drive ecosystem change in the later stages and larger scales of grass invasions of arid lands, competition by P. ciliare can drive small-scale transformations earlier in the invasion. Linking competition-induced transformation rates with

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

    OpenAIRE

    Techio, Vânia Helena; Davide, Lisete Chamma; Pereira, Antônio Vander

    2006-01-01

    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 proge...

  4. A proteomic style approach to characterize a grass mix product reveals potential immunotherapeutic benefit.

    Science.gov (United States)

    Bullimore, Alan; Swan, Nicola; Alawode, Wemimo; Skinner, Murray

    2011-09-01

    Grass allergy immunotherapies often consist of a mix of different grass extracts, each containing several proteins of different physiochemical properties; however, the subtle contributions of each protein are difficult to elucidate. This study aimed to identify and characterize the group 1 and 5 allergens in a 13 grass extract and to standardize the extraction method. The grass pollens were extracted in isolation and pooled and also in combination and analyzed using a variety of techniques including enzyme-linked immunosorbent assay, liquid chromatog-raphy-mass spectrometry, and sodium dodecyl sulfate-polyacrylam-ide gel electrophoresis. Gold-staining and IgE immunoblotting revealed a high degree of homology of protein bands between the 13 species and the presence of a densely stained doublet at 25-35 kD along with protein bands at approximately 12.5, 17, and 50 kD. The doublet from each grass species demonstrated a high level of group 1 and 5 interspecies homology. However, there were a number of bands unique to specific grasses consistent with evolutionary change and indicative that a grass mix immunotherapeutic could be considered broad spectrum. Sodium dodecyl sulfate-polyacrylamide gel electro-phoresis and IgE immunoblotting showed all 13 grasses share a high degree of homology, particularly in terms of group 1 and 5 allergens. IgE and IgG enzyme-linked immunosorbent assay potencies were shown to be independent of extraction method.

  5. Reversing land degradation through grasses: a systematic meta-analysis in the Indian tropics

    Science.gov (United States)

    Mandal, Debashis; Srivastava, Pankaj; Giri, Nishita; Kaushal, Rajesh; Cerda, Artemi; Meherul Alam, Nurnabi

    2017-02-01

    Although intensive agriculture is necessary to sustain the world's growing population, accelerated soil erosion contributes to a decrease in the environmental health of ecosystems at local, regional and global scales. Reversing the process of land degradation using vegetative measures is of utmost importance in such ecosystems. The present study critically analyzes the effect of grasses in reversing the process of land degradation using a systematic review. The collected information was segregated under three different land use and land management situations. Meta-analysis was applied to test the hypothesis that the use of grasses reduces runoff and soil erosion. The effect of grasses was deduced for grass strip and in combination with physical structures. Similarly, the effects of grasses were analyzed in degraded pasture lands. The overall result of the meta-analysis showed that infiltration capacity increased approximately 2-fold after planting grasses across the slopes in agricultural fields. Grazing land management through a cut-and-carry system increased conservation efficiencies by 42 and 63 % with respect to reduction in runoff and erosion, respectively. Considering the comprehensive performance index (CPI), it has been observed that hybrid Napier (Pennisetum purpureum) and sambuta (Saccharum munja) grass seem to posses the most desirable attributes as an effective grass barrier for the western Himalayas and Eastern Ghats, while natural grass (Dichanthium annulatum) and broom grass (Thysanolaena maxima) are found to be most promising grass species for the Konkan region of the Western Ghats and the northeastern Himalayan region, respectively. In addition to these benefits, it was also observed that soil carbon loss can be reduced by 83 % with the use of grasses. Overall, efficacy for erosion control of various grasses was more than 60 %; hence, their selection should be based on the production potential of these grasses under given edaphic and agro

  6. Bud-bank and tiller dynamics of co-occurring C3 caespitose grasses in mixed-grass prairie.

    Science.gov (United States)

    Ott, Jacqueline P; Hartnett, David C

    2015-09-01

    Tiller recruitment from the belowground bud bank of caespitose grasses influences their ability to monopolize local resources and, hence, their genet fitness. Differences in bud production and outgrowth among tiller types within a genet and among species may explain co-occurrence of caespitose grasses. This study aimed to characterize genet bud-bank and tiller production and dynamics in two co-occurring species and compare their vegetative reproductive strategies. Bud-bank and tiller dynamics of Hesperostipa comata and Nassella viridula, dominant C3 caespitose grasses in the northern mixed-grass prairie of North America, were assessed throughout an annual cycle. The two species showed similar strategies, maintaining polycyclic tillers and thus creating mixed-age genet bud banks comprising multiple bud cohorts produced in different years. Vegetative tillers produced the majority of buds, whereas flowering tillers contributed little to the bud bank. Buds lived for at least 2 yr and were maintained in multiple developmental stages throughout the year. Because bud longevity rarely exceeded tiller longevity, tiller longevity drove turnover within the bud bank. Tiller population dynamics, more than bud production per tiller, determined the differential contribution of tiller types to the bud bank. Nassella viridula had higher bud production per tiller, a consistent annual tiller recruitment density, and greater longevity of buds on senesced and flowering tillers than H. comata. Co-occurring C3 caespitose grasses had similar bud-bank and tiller dynamics contributing to genet persistence but differed in bud characteristics that could affect genet longevity and species coexistence. © 2015 Botanical Society of America.

  7. Spatiotemporal Variation in the Environmental Controls of C4-Grass Origin and Ecology: Insights from Grass-Pollen δ13C Data

    Science.gov (United States)

    Nelson, D. M.; Urban, M.; Hu, F.

    2014-12-01

    Understanding the environmental factors controlling the origin and shifting abundance of C4 grasses in Earth's history is useful for projecting the response of C4-grass dominated grasslands to future environmental change. Unfortunately, grass pollen is typically morphologically indistinct, making palynological analysis a blunt tool for studying C4-grasses in the paleorecord. δ13C of individual grass-pollen grains using a spooling wire microcombustion device interfaced with an isotope ratio mass spectrometer (Single Pollen Isotope Ratio AnaLysis, SPIRAL) overcomes this challenge and the potential biases of δ13C data from other substrates (e.g. leaf waxes). To assess the presence and relative abundance of C3- and C4-grass pollen in samples of unknown composition, we developed a hierarchical Bayesian model, trained with ~1,900 δ13C values from pollen grains of 31 grass species. Surface-sediment data from Africa, Australia, and North America demonstrate the reliability of this technique for quantifying C4-grass abundance on the landscape. To investigate the timing and control of the origin of C4-grasses we analyzed samples from the Oligocene-Miocene from Europe and from the Eocene from North America. Results indicate that C4 grasses appeared on the landscape of southwest Europe no later than the early Oligocene, implying that low atmospheric pCO2 may not have been the main driver and/or precondition for the development of C4 photosynthesis in the grass family. In contrast, we found no evidence for C4 grasses in the southeast United States before pCO2 fell. In application of SPIRAL to the late Quaternary, we found that shifts in pCO2 and moisture balance exerted key controls on the relative abundance of C3 and C4 grasses in Africa and Australia. Overall, our results imply that as in the past, future changes in the C3/C4 composition of grass-dominated ecosystems will likely exhibit striking spatiotemporal variability as a result of differing combinations of

  8. Status of exotic grasses and grass-like vegetation and potential impacts on wildlife in New England

    Science.gov (United States)

    DeStefano, Stephen

    2013-01-01

    The Northeastern section of the United States, known as New England, has seen vast changes in land cover and human population over the past 3 centuries. Much of the region is forested; grasslands and other open-land cover types are less common, but provide habitat for many species that are currently declining in abundance and distribution. New England also consists of some of the most densely populated and developed states in the country. The origin, distribution, and spread of exotic species are highly correlated with human development. As such, exotics are common throughout much of New England, including several species of graminoids (grasses and grass-like plants such as sedges and rushes). Several of the more invasive grass species can form expansive dense mats that exclude native plants, alter ecosystem structure and functions, and are perceived to provide little-to-no value as wildlife food or cover. Although little research has been conducted on direct impacts of exotic graminoids on wildlife populations in New England, several studies on the common reed (Phragmites australis) in salt marshes have shown this species to have variable effects as cover for birds and other wildlife, depending on the distribution of the plant (e.g., patches and borders of reeds are used more by wildlife than expansive densely growing stands). Direct impacts of other grasses on wildlife populations are largely unknown. However, many of the invasive graminoid species that are present in New England have the capability of outcompeting native plants and thereby potentially affecting associated fauna. Preservation, protection, and restoration of grassland and open-land cover types are complex but necessary challenges in the region to maintain biological and genetic diversity of grassland, wetland, and other open-land obligate species.

  9. The Need of Belonging and Sense of Belonging versus Effectiveness of Coping

    Directory of Open Access Journals (Sweden)

    Wilczyńska Agnieszka

    2015-03-01

    Full Text Available The aim of this research was to describe the dependence between the need for and sense of belonging and symptoms of depression vs. one’s capacity to cope effectively. Using path analysis of our data (N = 178, we found direct patterns, in which both depression symptoms and life satisfaction depend to a considerable degree on the sense of belonging. The belonging need influences, in a direct way, the coping focused on the search for social support. Undertaking active techniques of coping, including confrontation with a stressful situation and its negative controlling impact, depends on having a high level of the sense of belonging. In contrast, individuals who cope by means of taking psychoactive drugs show the symptoms of depression.

  10. 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.)

  11. Swine wastewater treatment using vertical subsurface flow constructed wetland planted with Napier grass

    Directory of Open Access Journals (Sweden)

    Pantip Klomjek

    2016-09-01

    Full Text Available This research aims to investigate the pollutant removal efficiencies in swine wastewater using a vertical subsurface flow constructed wetland (VSF CW planted with two species of Napier grass. The grass productivities were also cultivated and compared in order to provide information for species selection. Twelve treatment units were set up with the VSF CWs planted with Giant Napier grass (Pennisetum purpureum cv. King grass and Dwarf Napier grass (Pennisetum purpureum cv. Mott. with 2 and 5 cm d−1 of hydraulic loading rates (HLR. Comparisons of removal efficiency and grass productivity were analyzed using Duncan's Multiple Range Test and t-test at the significant level 0.05. Both species of Napier grass performed more than 70% of removal efficiency of BOD and TKN. The VSF CW planted with Giant Napier grass at 5 cm d−1 HLR performed the highest BOD removal efficiency of 94 ± 1%, while the 2 cm d−1 HLR removed COD with efficiency of 64 ± 6%. The results also showed the effluent from all treatment units contained averages of BOD, COD, TSS, TKN and pH that followed Thailand's swine wastewater quality standard. Average fresh yields and dry yields were between 4.6 ± 0.4 to 15.2 ± 1.2 and 0.5 ± 0.1 to 2.2 ± 0.1 kg m−2, respectively. The dry yields obtained from four cutting cycles in five months of CW system operation were higher than the ones planted with a traditional method, but declined continuously after each cutting cycle. Both species of Napier grass indicated their suitability to be used in the VSF CW for swine wastewater treatment.

  12. The perennial ryegrass GenomeZipper: targeted use of genome resources for comparative grass genomics.

    Science.gov (United States)

    Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F X; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

    2013-02-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species.

  13. 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...

  14. Phylogenetic analysis reveals multiple introductions of Cynodon species in Australia.

    Science.gov (United States)

    Jewell, M; Frère, C H; Harris-Shultz, K; Anderson, W F; Godwin, I D; Lambrides, C J

    2012-11-01

    The distinction between native and introduced flora within isolated land masses presents unique challenges. The geological and colonisation history of Australia, the world's largest island, makes it a valuable system for studying species endemism, introduction, and phylogeny. Using this strategy we investigated Australian cosmopolitan grasses belonging to the genus Cynodon. While it is believed that seven species of Cynodon are present in Australia, no genetic analyses have investigated the origin, diversity and phylogenetic history of Cynodon within Australia. To address this gap, 147 samples (92 from across Australia and 55 representing global distribution) were sequenced for a total of 3336bp of chloroplast DNA spanning six genes. Data showed the presence of at least six putatively introduced Cynodon species (C. transvaalensis, C. incompletus, C. hirsutus, C. radiatus, C. plectostachyus and C. dactylon) in Australia and suggested multiple recent introductions. C. plectostachyus, a species often confused with C. nlemfuensis, was not previously considered to be present in Australia. Most significantly, we identified two common haplotypes that formed a monophyletic clade diverging from previously identified Cynodon species. We hypothesise that these two haplotypes may represent a previously undescribed species of Cynodon. We provide further evidence that two Australian native species, Brachyachne tenella and B. convergens belong in the genus Cynodon and, therefore, argue for the taxonomic revision of the genus Cynodon. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A Conceptual Shift in Studies of Belonging and the Politics of Belonging

    Directory of Open Access Journals (Sweden)

    Eva Youkhana

    2015-07-01

    Full Text Available The study of belonging, its underlying notions, and the politics of belonging shows that social, political, and territorial demarcations are still based on essentialist conceptions of the collective. These are often applied and reproduced in the social sciences as a result of methodological nationalism. Space-sensitive studies of migration and globalization and a return to the material have recently challenged social constructivist lines of argumentation and have provoked a conceptual shift from analytical categories with inherent spatiality, territoriality, and boundary marking to concepts based on movement and flow. In this paper the analysis of belonging and the related politics of belonging in migration studies incorporates space as an analytical category that cross-cuts established categorizations such as race, class, gender, and stage in the life cycle, and integrates a material semiotic perspective more systematically into the study of social relations at the intersection of the social categories mentioned. A new concept of belonging is defined which reflects the complex relations that individuals have with other people, circulating objects, artefacts, and changing social, political, and cultural landscapes, thus mirroring both the material conditions and the underlying power relations. Such an understanding of belonging proceeds from social naturalizations and fixations to the multiplicity and situatedness of individual attachments, which entangle social, imagined, and sensual-material relations that are constantly re-articulated and re-negotiated by actors in their day-to-day practices. In such a reading, belonging comes into being as a result of individual life stories, versatile contexts, and situated experiences and acts. In times of constant exchange through travel, mass media, and communication technologies, the conceptualization of belonging questions established sociocultural and political demarcations, indicates the

  16. NITROGEN CONTENT AND DRY-MATTER DIGESTIBILITY OF GUINEA AND SABI GRASSES AS INFLUENCED BY TREE LEGUME CANOPY

    Directory of Open Access Journals (Sweden)

    Andi Lagaligo Amar

    2012-08-01

    Full Text Available A research study was undertaken to study the grass layer across a mini landscape dominated by tree legume Albizia lebbeck to explore the nutritional differences of two introduced grasses, guinea grass (Panicum maximum and sabi grass (Urochloa mosambicensis, paying particular attention to the presence or absence of tree legume canopy of Albizia lebbeck. The two grass species showed a tendency to replace the native spear grass (Heteropogon contortus; their dominance was more or less complete under tree canopies but was increasing in open areas between trees. Nutritional differences were examined by nitrogen concentration and dry matter digestibility. For comparison, Heteropogon contortus, a native species only found in the open, was included in the nutritional determination using the same methods as the guinea and sabi grasses. The quality parameters of the pasture species were statistically compared (LSD, P=0.05. The quality of herbage was different between the species. Urochloa mosambicensis was better than Panicum maximum. In the open, sabi grass has higher N content (0.62% than guinea grass (0.55%, but they were similar when grown under the canopy (0.69% and 0.72%, respectively. Sabi grass has consistently higher dry matter digestibility (41.39% and 36.83%, respectively under the canopy and in the open, than guinea grass (27.78% and 24.77%. These two species are much higher in both N concentration and dry matter digestibility than the native spear grass. The native species has contained 0.28% N, and 17.65% digestible dry matter. The feeding values of herbage were influenced by the canopy factor. Both guinea and sabi grasses have better quality when grown under the tree canopies than in between canopies. Nitrogen concentration and dry matter digestibility of the guinea grass under canopy were, 0.72% and 27.78%, respectively, significantly higher than those from the open area, 0.55% and 24.77%. Similarly, herbage of sabi grass under canopy has 0

  17. Host status of false brome grass to the leaf rust fungus Puccinia brachypodii and the stripe rust fungus P. Striiformis

    NARCIS (Netherlands)

    Barbieri, M.; Marcel, T.C.; Niks, R.E.

    2011-01-01

    Purple false brome grass (Brachypodium distachyon) has recently emerged as a model system for temperate grasses and is also a potential model plant to investigate plant interactions with economically important pathogens such as rust fungi. We determined the host status of five Brachypodium species

  18. Feasibility of Invasive Grass Detection in a Desertscrub Community Using Hyperspectral Field Measurements and Landsat TM Imagery

    OpenAIRE

    Olsson, Aaryn D.; Leeuwen, Willem J.D. van; Marsh, Stuart E.

    2011-01-01

    Invasive species’ phenologies often contrast with those of native species, representing opportunities for detection of invasive species with multi-temporal remote sensing. Detection is especially critical for ecosystem-transforming species that facilitate changes in disturbance regimes. The African C4 grass, Pennisetum ciliare, is transforming ecosystems on three continents and a number of neotropical islands by introducing a grass-fire cycle. However, previous attempts at discriminating P. c...

  19. 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

  20. Sox genes in grass carp (Ctenopharyngodon idella with their implications for genome duplication and evolution

    Directory of Open Access Journals (Sweden)

    Tong Jingou

    2006-11-01

    Full Text Available Abstract The Sox gene family is found in a broad range of animal taxa and encodes important gene regulatory proteins involved in a variety of developmental processes. We have obtained clones representing the HMG boxes of twelve Sox genes from grass carp (Ctenopharyngodon idella, one of the four major domestic carps in China. The cloned Sox genes belong to group B1, B2 and C. Our analyses show that whereas the human genome contains a single copy of Sox4, Sox11 and Sox14, each of these genes has two co-orthologs in grass carp, and the duplication of Sox4 and Sox11 occurred before the divergence of grass carp and zebrafish, which support the "fish-specific whole-genome duplication" theory. An estimation for the origin of grass carp based on the molecular clock using Sox1, Sox3 and Sox11 genes as markers indicates that grass carp (subfamily Leuciscinae and zebrafish (subfamily Danioninae diverged approximately 60 million years ago. The potential uses of Sox genes as markers in revealing the evolutionary history of grass carp are discussed.

  1. Health and nomadism: territory and belonging

    Directory of Open Access Journals (Sweden)

    Betina Hillesheim

    2017-11-01

    Full Text Available This article discusses how territory and linking notions articulate with the health field in Brazil, in view of the relations that are established between health staff and certain social groups who see in the movement a logic of life, survival and resistance: the nomads. The concept of territory is an important organizer of Brazilian’s public policies, and is closely related to inclusion. The data were collected through participant observation of the daily work of two teams of Family Health Strategy, in a medium-sized city located in the state of Rio Grande do Sul. For these services, nomadism is seen as a nuisance. On the other hand, include not only acquires a sense of attachment and population control, but the demarcation of belonging territories, from the investment of the relation of users with health services.

  2. THE PREVALENCE OF LERNAEID ECTOPARASITES IN GRASS CARP (CTENOPHARYNGODON IDELLA

    Directory of Open Access Journals (Sweden)

    Z. TASAWAR, S. ZAFAR, M. H. LASHARI AND C. S. HAYAT1

    2009-05-01

    Full Text Available The present study was conducted to investigate the prevalence of lernaeid ectoparasites in grass carp (Ctenopharyngodon idella. For this purpose, 597 fishes (Ctenopharyngodon idella were examined for lernaeid ectoparasites at a private fish farm located in Multan, Pakistan. Four species of the genus Lernaea i.e. L. cyprinacea, L. polymorpha, L. oryzophila, and L. lophiara were recorded. It was observed that L. polymorpha had the highest (P20 cm.

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

    OpenAIRE

    A.O. Idris; C. Kijora; A.M. Salih; I. Bushara; H.A.A. Elbukhary

    2012-01-01

    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 differe...

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

    OpenAIRE

    Clair Jorge Olivo; Carlos Alberto Agnolin; Priscila Flôres Aguirre; Cláudia Marques de Bem; Tiago Luís da Ros de Araújo; Michelle Schalemberg Diehl; Gilmar Roberto Meinerz

    2014-01-01

    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 gra...

  5. The Neutral Detergent Fiber Digestibility of Some Tropical Grasses at Different Stage of Maturity

    Directory of Open Access Journals (Sweden)

    P Mahyuddin

    2009-09-01

    Full Text Available The digestibility of neutral detergent fiber (IVNDFD was determined by Telly and Terry methods in vitro on 5 tropical grasses species, Sorghum, Themeda, Iseilema, Brachyacne and Dicanthium. Stem and leaf samples were harvested at different maturity stages, started from early flowering stage to the stage when the grasses were dried. In general, IVNDFD ranged from 22% to 41%. Stages of maturity affected IVNDFD in 4 species; IVNDFD was higher in the stems than in the leaves for 2 species out of 5 species of grasses; the rest was similar. There was no correlation between NDF and IVNDFD, showing that NDF degradability in the rumen was vary. Digestibility potential of NDF (PDNDF varied from 21% to 44% and has negative correlation with IVNDFD (r=0.75. Growth affected PDNDF in 2 species; and 3 out 5 species observed showed PDNDF in the leaves was higher than that in the stems. Negative correlation was exist between dry matter digestibility (IVDMD, water soluble extract (WSE and protein with PDNDF. Grasses with stated PDNDF values have relatively high NDF retention in the rumen, which will cause low NDF or dry matter consumption. (Animal Production 11(3: 189-195 (2009Key Words: NDF digestibility, tropical grasses, stem, leaves, maturity stage

  6. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Science.gov (United States)

    Talukder, Shyamal K.; Saha, Malay C.

    2017-01-01

    Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS) are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs). Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder. PMID:28798766

  7. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Shyamal K. Talukder

    2017-07-01

    Full Text Available Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs. Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder.

  8. Using multi-date satellite imagery to monitor invasive grass species distribution in post-wildfire landscapes: An iterative, adaptable approach that employs open-source data and software

    Science.gov (United States)

    West, Amanda M.; Evangelista, Paul H.; Jarnevich, Catherine S.; Kumar, Sunil; Swallow, Aaron; Luizza, Matthew; Chignell, Steve

    2017-01-01

    Among the most pressing concerns of land managers in post-wildfire landscapes are the establishment and spread of invasive species. Land managers need accurate maps of invasive species cover for targeted management post-disturbance that are easily transferable across space and time. In this study, we sought to develop an iterative, replicable methodology based on limited invasive species occurrence data, freely available remotely sensed data, and open source software to predict the distribution of Bromus tectorum (cheatgrass) in a post-wildfire landscape. We developed four species distribution models using eight spectral indices derived from five months of Landsat 8 Operational Land Imager (OLI) data in 2014. These months corresponded to both cheatgrass growing period and time of field data collection in the study area. The four models were improved using an iterative approach in which a threshold for cover was established, and all models had high sensitivity values when tested on an independent dataset. We also quantified the area at highest risk for invasion in future seasons given 2014 distribution, topographic covariates, and seed dispersal limitations. These models demonstrate the effectiveness of using derived multi-date spectral indices as proxies for species occurrence on the landscape, the importance of selecting thresholds for invasive species cover to evaluate ecological risk in species distribution models, and the applicability of Landsat 8 OLI and the Software for Assisted Habitat Modeling for targeted invasive species management.

  9. A genomic approach to elucidating grass flower development

    Directory of Open Access Journals (Sweden)

    Dornelas Marcelo C.

    2001-01-01

    Full Text Available In sugarcane (Saccharum sp as with other species of grass, at a certain moment of its life cycle the vegetative meristem is converted into an inflorescence meristem which has at least two distinct inflorescence branching steps before the spikelet meristem terminates in the production of a flower (floret. In model dicotyledonous species such successive conversions of meristem identities and the concentric arrangement of floral organs in specific whorls have both been shown to be genetically controlled. Using data from the Sugarcane Expressed Sequence Tag (EST Project (SUCEST database, we have identified all sugarcane proteins and genes putatively involved in reproductive meristem and flower development. Sequence comparisons of known flower-related genes have uncovered conserved evolutionary pathways of flower development and flower pattern formation between dicotyledons and monocotyledons, such as some grass species. We have paid special attention to the analysis of the MADS-box multigene family of transcription factors that together with the APETALA2 (AP2 family are the key elements of the transcriptional networks controlling plant reproductive development. Considerations on the evolutionary developmental genetics of grass flowers and their relation to the ABC homeotic gene activity model of flower development are also presented.

  10. Morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania

    OpenAIRE

    Špakaitė, Ina

    2014-01-01

    The aim of the study was to investigate the morphology, ecology and phylogeny of cyanobacteria belonging to genera Nostoc and Desmonostoc in Lithuania. The detailed research of freshwater and terrestrial Nostoc and Desmonostoc species provided new data on taxonomy, biology and ecology of these cyanobacteria and the overall diversity of algae in Lithuania. 20 Nostoc species and two intraspecific taxa, and 18 taxa to the Nostoc genus level were identified. Twelve Nostoc species and intraspecifi...

  11. Dynamika przyrostu masy i produktywność stokłosy bezostnej i stokłosy uniolowatej przy zróżnieowanym nawożeniu azotem w doświadczeniu polowym. Cz. II. Jakość plonu [Dynamics of mass increase and productivity of smooth brome grass and rescue grass with different nitrogen fertilization in field experiments. Part II. Quality of yield

    Directory of Open Access Journals (Sweden)

    Henryk Skrabka

    2015-06-01

    Full Text Available The contents of protein, amino acids, reducing sugars, fibre (ADF, lignin (ADL and mineral components in tissues of smooth brome grass – Bromus inermis and rescue grass – Bromus unioloides were determined. The purpose of this investigation was to compare the nutritive value of either species of grass.

  12. Morphological characteristics of the interspecies hybrid between Sorghum and Sudan grass under intensive nitrogen nutrition

    Directory of Open Access Journals (Sweden)

    Ikanović Jela

    2013-01-01

    Full Text Available The object of this study was a two-year trial (2009 and 2010 regarding variability of morphological characteristics of species belonging to Sorghum genus, more specifically interspecies hybrid between sorghum and Sudan grass Siloking as affected by different applications of nitrogen. The following morphological characteristics were analysed: plant height, number of leaves, leaf ratio, stem ratio, and number of shoots. Samples were taken from the first cut when the effect of the applied nitrogen doses was the strongest. The results showed that increasing nitrogen quantities significantly affected the tested morphological characteristics, especially the intensity of tillering (increased number of secondary stems, number of the formed leaves, and ratio of leaf weight in the total above-ground biomass. The effect of applied nitrogen depended on the weather conditions, i.e. distribution of precipitation, so that plants reached maximum height when 105 kg N ha-1 was applied in the dry year and 180 kg N ha-1 in the wet year. [Projekat Ministarstva nauke Republike Srbije, br. TR 31078 i br. TR 31022

  13. 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

  14. Differentiation of plant age in grasses using remote sensing

    Science.gov (United States)

    Knox, Nichola M.; Skidmore, Andrew K.; van der Werff, Harald M. A.; Groen, Thomas A.; de Boer, Willem F.; Prins, Herbert H. T.; Kohi, Edward; Peel, Mike

    2013-10-01

    Phenological or plant age classification across a landscape allows for examination of micro-topographical effects on plant growth, improvement in the accuracy of species discrimination, and will improve our understanding of the spatial variation in plant growth. In this paper six vegetation indices used in phenological studies (including the newly proposed PhIX index) were analysed for their ability to statistically differentiate grasses of different ages in the sequence of their development. Spectra of grasses of different ages were collected from a greenhouse study. These were used to determine if NDVI, NDWI, CAI, EVI, EVI2 and the newly proposed PhIX index could sequentially discriminate grasses of different ages, and subsequently classify grasses into their respective age category. The PhIX index was defined as: (AVNIRn+log(ASWIR2n))/(AVNIRn-log(ASWIR2n)), where AVNIRn and ASWIR2n are the respective normalised areas under the continuum removed reflectance curve within the VNIR (500-800 nm) and SWIR2 (2000-2210 nm) regions. The PhIX index was found to produce the highest phenological classification accuracy (Overall Accuracy: 79%, and Kappa Accuracy: 75%) and similar to the NDVI, EVI and EVI2 indices it statistically sequentially separates out the developmental age classes. Discrimination between seedling and dormant age classes and the adult and flowering classes was problematic for most of the tested indices. Combining information from the visible near infrared (VNIR) and shortwave infrared region (SWIR) region into a single phenological index captures the phenological changes associated with plant pigments and the ligno-cellulose absorption feature, providing a robust method to discriminate the age classes of grasses. This work provides a valuable contribution into mapping spatial variation and monitoring plant growth across savanna and grassland ecosystems.

  15. Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna.

    Science.gov (United States)

    Priyadarshini, K V R; Prins, Herbert H T; de Bie, Steven; Heitkönig, Ignas M A; Woodborne, Stephan; Gort, Gerrit; Kirkman, Kevin; Fry, Brian; de Kroon, Hans

    2014-04-01

    A key question in savanna ecology is how trees and grasses coexist under N limitation. We used N stable isotopes and N content to study N source partitioning across seasons from trees and associated grasses in a semi-arid savanna. We also used (15)N tracer additions to investigate possible redistribution of N by trees to grasses. Foliar stable N isotope ratio (δ(15)N) values were consistent with trees and grasses using mycorrhiza-supplied N in all seasons except in the wet season when they switched to microbially fixed N. The dependence of trees and grasses on mineralized soil N seemed highly unlikely based on seasonal variation in mineralization rates in the Kruger Park region. Remarkably, foliar δ(15)N values were similar for all three tree species differing in the potential for N fixation through nodulation. The tracer experiment showed that N was redistributed by trees to understory grasses in all seasons. Our results suggest that the redistribution of N from trees to grasses and uptake of N was independent of water redistribution. Although there is overlap of N sources between trees and grasses, dependence on biological sources of N coupled with redistribution of subsoil N by trees may contribute to the coexistence of trees and grasses in semi-arid savannas.

  16. Ecology, genetics, and biological control of invasive annual grasses in the Great Basin

    Science.gov (United States)

    Several annual grass species native to Eurasia, including cheatgrass (Bromus tectorum), red brome (B. rubens), and medusahead (Taeniatherum caput-medusae) have become invasive in the western USA. These invasive species degrade rangelands by compromising forage, outcompeting native flora, and exacerb...

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

    International Nuclear Information System (INIS)

    Oehlenschlaeger, M.; Gissel-Nielsen, G.

    1989-11-01

    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 137 Cs and 134 Cs. 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. 137 Cs was added to the clay-loam. The organic soil, which was contaminated with 137 Cs from the Chernobyl accident, was supplied with 134 Cs. Sila barley and Italian rye-grass were identified among the species tested as plants with a relative high uptake of radio-caesium. (author)

  18. Monoclonal antibodies to the major Lolium perenne (rye grass) pollen allergen Lol p I (Rye I).

    Science.gov (United States)

    Kahn, C R; Marsh, D G

    1986-12-01

    Thirteen monoclonal antibodies (MAbs) were produced against Lol p I (Rye I), the major Lolium perenne (rye grass) pollen allergen. Spleen cells from A/J and SJL mice immunized with highly purified Lol p I (Lol I) were allowed to fuse with cells from the non-secreting Sp2/0-Ag14 myeloma cell line. Each MAb was analyzed for antigenic specificity by radioimmunoassay (RIA) using 125I-Lol I. The epitope specificities of seven of the MAbs were examined by competitive binding against a labelled standard MAb for the Lol I antigen (Ag). The dissociation constant, Kd, of one MAb (No. 3.2) that was studied most extensively was determined by double Ab RIA to be 3.5 X 10(-6) L/M. This MAb recognized the related 27,000-30,000 Group I glycoproteins found in the pollens of nine other species of grass pollens tested, including weak binding to Bermuda grass Group I (Cyn d I), which by conventional analysis using polyclonal anti-Lol I serum shows no detectable binding. Monoclonal antibody No. 3.2 was coupled covalently to Sepharose 4B and used to prepare highly purified Lol I from a partially purified rye pollen extract. Finally, an RIA was developed which permitted the analysis of the Group I components in rye grass and nine other grass pollen species. The latter assay is likely to prove useful in the standardization of grass pollen extracts according to their Group I contents.

  19. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben

    2013-01-01

    (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold......Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass...... to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous...

  20. Invasive Andropogon gayanus (gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna.

    Science.gov (United States)

    Rossiter-Rachor, N A; Setterfield, S A; Douglas, M M; Hutley, L B; Cook, G D; Schmidt, S

    2009-09-01

    Invasion by the African grass Andropogon gayanus is drastically altering the understory structure of oligotrophic savannas in tropical Australia. We compared nitrogen (N) relations and phenology of A. gayanus and native grasses to examine the impact of invasion on N cycling and to determine possible reasons for invasiveness of A. gayanus. Andropogon gayanus produced up to 10 and four times more shoot phytomass and root biomass, with up to seven and 2.5 times greater shoot and root N pools than native grass understory. These pronounced differences in phytomass and N pools between A. gayanus and native grasses were associated with an altered N cycle. Most growth occurs in the wet season when, compared with native grasses, dominance of A. gayanus was associated with significantly lower total soil N pools, lower nitrification rates, up to three times lower soil nitrate availability, and up to three times higher soil ammonium availability. Uptake kinetics for different N sources were studied with excised roots of three grass species ex situ. Excised roots of A. gayanus had an over six times higher-uptake rate of ammonium than roots of native grasses, while native grass Eriachne triseta had a three times higher uptake rate of nitrate than A. gayanus. We hypothesize that A. gayanus stimulates ammonification but inhibits nitrification, as was shown to occur in its native range in Africa, and that this modification of the soil N cycle is linked to the species' preference for ammonium as an N source. This mechanism could result in altered soil N relations and could enhance the competitive superiority and persistence of A. gayanus in Australian savannas.

  1. Enhancing GRASS data communication with videographic technology

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, R.G. [Argonne National Lab., IL (United States); Gerdes, D.; Youngs, D. [Army Construction Engineering Research Lab., Champaign, IL (United States)

    1992-07-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  2. Enhancing GRASS data communication with videographic technology

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, R.G. (Argonne National Lab., IL (United States)); Gerdes, D.; Youngs, D. (Army Construction Engineering Research Lab., Champaign, IL (United States))

    1992-01-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  3. Thermogravimetric analysis of forest understory grasses

    Science.gov (United States)

    Thomas Elder; John S. Kush; Sharon M. Hermann

    2011-01-01

    Forest understory grasses are of significance in the initiation, establishment and maintenance of fire, whether used as a management tool or when occurring as wildfire. The fundamental thermal properties of such grasses are critical to their behavior in fire situations and have been investigated in the current work by the application of thermogravimetric analysis (TGA...

  4. The Perennial Ryegrass GenomeZipper: Targeted Use of Genome Resources for Comparative Grass Genomics1[C][W

    Science.gov (United States)

    Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F.X.; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

    2013-01-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species. PMID:23184232

  5. 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

  6. DEPENDENCE OF GRASS COVER TAXONOMIC AND ECOLOGICAL STRUCTURE ON THE ANTHROPOGENIC IMPACT IN FOREST ECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    N. V. Miroshnik

    2016-01-01

    Full Text Available Pine forests Chigirinsky Bor grow on fresh sod-podzolic soils formed on ancient alluvial deposits. Pine forests are characterized by stringent moisture regimes and constantly suffer from lack of productive moisture in soil.  Industrial development of Cherkasy in 60th years of ХХ century leaded air pollution and emissions of SO2, NOx, NH3, and dust. This contributed to significant negative influence on the surrounding forest ecosystems from enterprises of  Cherkassy industrial agglomeration. The grass cover in pine stands of Chigirinsky Bor transforms into xerophytic grasses and ruderal communities under the impact of negative biotic and abiotic factors. They are namely the anthropogenic violation of forest conditions, stands decline, recreational and industrial tree crowns understocking, xerophytic and heliophytic transformations of forest conditions. All the above mentioned caused strong ruderal and adventive transformation of grass cover. We registered the changes in nitrophilous plant spread regards the Cherkasy industrial agglomeration approaching which emits toxic with nitrogen-containing gases. Adventive and other non-forest species displace ferns and mosses, the ratio of ecomorfs is also changes due to increase of the quantity and development activation of annuals, xerophytic, ruderal, and nitrofil plants. The Asteraceae/Brassicaceae 3:1 ratio indicates significant anthropogenic violations in the region. We fixed the xerophytic, ruderal, and adventive transformation of grass cover in forest ecosystems. It is also founded the tendency of expanding the fraction of mesophilic plant species due to alterations in water regime (creation of Kremenchug reservoir and draining of floodplain Tyasmyn. When approaching the Cherkasy industrial agglomeration the grass cover degradation is clearly observed on the environmental profile. All this causes the forest ecosystem degradation and gradual loss of forest vegetation typical characteristics. We

  7. Notes on the genus Digitaria, with descriptions of new species

    NARCIS (Netherlands)

    Henrard, J.Th.

    1934-01-01

    Some years ago I had the opportunity to study more extensively a very interesting group of grasses, belonging to what is now accepted as a distinct genus, the genus Digitaria, formerly belonging as a subgenus to the genus Panicum. As to living plants of this group I was familiar with two european

  8. Molecular cloning, characterization and expression analysis of coagulation factor VII gene in grass carp (Ctenopharyngodon idella).

    Science.gov (United States)

    Liu, Qiaolin; Xu, Baohong; Xiao, Tiaoyi; Su, Jianming; Zhong, Lei

    2013-08-01

    Coagulation factor VII has been studied in several species but, to date, not in grass carp (Ctenopharyngodon idella), a commercially important freshwater fish found in China. In this study, the full-length cDNA of grass carp coagulation factor VII (GcCFVII) was cloned using a RACE-Ready cDNA Kit, grass carp were challenged with a hemorrhagic virus, and temporal expression profiles of GcCFVII in the thymus, gills, liver, spleen, and head kidney were examined at 0 h, 24 h, 48 h, 72 h, 96 h, and 138 h using fluorescence quantitative PCR. The results showed the 1480 bp GcCFVII to contain three conservative motifs: Gla, EGF-CA, and Tryp-SPc, similar to other species. Phylogenetic analysis showed the evolution of GcCFVII gene to be consistent with the evolution of the species. After viral challenge, GcCFVII expression in five tissues of grass carp showed different patterns of fluctuation. These results provide a solid basis for further investigation of GcCFVII and its relationship with grass carp hemorrhage. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Clement, Stephen L; Hu, Jinguo; Stewart, Alan V; Wang, Bingrui; Elberson, Leslie R

    2011-01-01

    Seed-borne Epichloë/Neotyphodium Glenn, Bacon, Hanlin (Ascomycota: Hypocreales: Clavicipitaceae) fungal endophytes in temperate grasses can provide protection against insect attack with the degree of host resistance related to the grass-endophyte symbiotum and the insect species involved in an interaction. Few experimental studies with wild grass-endophyte symbiota, compared to endophyte-infected agricultural grasses, have tested for anti-insect benefits, let alone for resistance against more than one insect species. This study quantified the preference and performance of the bird cherry oat-aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae) and the cereal leaf beetle, Oulema melanopus (L.) (Coleoptera: Chrysomelidae), two important pests of forage and cereal grasses, on Neotyphodium-infected (E+) and uninfected (E-) plants of the wild grass Alpine timothy, Phleum alpinum L. (Poales: Poaceae). The experiments tested for both constitutive and wound-induced resistance in E+ plants to characterize possible plasticity of defense responses by a wild E+ grass. The aphid, R. padi preferred E- over E+ test plants in choice experiments and E+ undamaged test plants constitutively expressed antibiosis resistance to this aphid by suppressing population growth. Prior damage of E+ test plants did not induce higher levels of resistance to R. padi. By contrast, the beetle, O. melanopus showed no preference for E+ or E- test plants and endophyte infection did not adversely affect the survival and development of larvae. These results extend the phenomenon of variable effects of E+ wild grasses on the preference and performance of phytophagous insects. The wild grass- Neotyphodium symbiotum in this study broadens the number of wild E+ grasses available for expanded explorations into the effects of endophyte metabolites on insect herbivory.

  10. Effects of a copper-tolerant grass (Agrostis capillaris) on the ecosystem of a copper-contaminated arable soil

    Energy Technology Data Exchange (ETDEWEB)

    Boon, G.T. [State Univ. Groningen (Netherlands); Bouwman, L.A.; Bloem, J.; Roemkens, P.F.A.M. [Research Inst. for Agrobiology and Soil Fertility, Haren (Netherlands)

    1998-10-01

    To test how a dysfunctioning ecosystem of a severely metal-polluted soil responds to renewed plant growth, a pot experiment was conducted with soil from an experimental arable field with pH and copper gradients imposed 13 years ago. In this experiment, four pH/copper combinations from this field were either planted with a pH- and copper-resistant grass cultivar or remained fallow. During a 10-week period, the dynamics of the microbial activity and of the abundances of bacteria, protozoa. and nematodes were measured, as were the dynamics of several chemical soil parameters. After 13 years of copper, which had resulted in severely reduced crop growth, no effects were observed on bacterial numbers, respiration, or protozoan numbers, but bacterial growth was strongly reduced in the low pH plots, and even more so in low pH plots enriched with copper. Of the organisms, only nematodes were negatively affected under conditions of high copper load at low pH. In these plots, numbers belonging to all feeding categories were strongly reduced. Planting of a copper-tolerant grass variety, Agrostis capillaris L. var. Parys Mountain, resulted within 10 weeks in faster bacterial growth and more protozoa and bacterivorous nematodes in comparison with fallow controls; these effects were markedly strongest in the acidic, copper-enriched soils. During incubation, fungivorous nematodes increased in all treatments, in fallow and in planted pots and in the pots with high-copper, low-pH soil. The results of this experiment suggest that introduction of plant growth is one of the major causes of increased biological activity in acidic contaminated soils. Planting such soils with metal-tolerant plant species can reestablish the necessary food base to support soil organism growth, and this can lead to numerous positive effects, reversing the loss of soil functions due to the high copper levels under acidic conditions.

  11. Production of tropical forage grasses under different shading levels

    Directory of Open Access Journals (Sweden)

    Francisco Eduardo Torres

    2017-12-01

    Full Text Available This study aimed to evaluate the forage production of three tropical forage grasses under different shading levels. The experiment was conducted in a greenhouse at Universidade Estadual de Mato Grosso do Sul, University Unit of Aquidauana (UEMS/UUA, in a soil classified as Ultisol sandy loam texture. The treatments consisted of three grasses species combinations (B. brizantha cv. Marandu, B. decumbens cv. Basilisck and Panicum maximum cv. Tanzania, submitted to four shading levels (0, 30, 50 and 75%, arranged in a completely randomized blocks design in a factorial 3 x 4, with eight replications. After harvest, the plants were separated into shoot and roots for determination of shoot fresh mass (SFM, shoot dry mass (SDM and roots dry mass production. After analysis of variance, the qualitative factor was subjected to comparison of averages by Tukey’s test, and the quantitative factor to analysis of polynomial regression, being interactions appropriately unfolded. It was verified that B. decumbens, by its linearly increasing production of forage and less decrease of root formation, is the most recommended for shading conditions compared to grasses Tanzania and Marandu.

  12. 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

  13. Grass leaves as potential hominin dietary resources.

    Science.gov (United States)

    Paine, Oliver C C; Koppa, Abigale; Henry, Amanda G; Leichliter, Jennifer N; Codron, Daryl; Codron, Jacqueline; Lambert, Joanna E; Sponheimer, Matt

    2018-04-01

    Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C 4 component in the diets of most taxa, and grass leaves are the single most abundant C 4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of grass leaves with the plants growing alongside them in African savanna habitats. We also compare grass leaves to the leaves consumed by other hominoids and demonstrate that many, though by no means all, compare favorably with the nutritional and mechanical properties of known primate foods. Our data reveal that grass leaves exhibit tremendous variation and suggest that future reconstructions of hominin dietary ecology take a more nuanced approach when considering grass leaves as a potential hominin dietary resource. Copyright © 2017. Published by Elsevier Ltd.

  14. 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.

  15. Morphological description of Cosmocerca sp. (Nematoda: Cosmocerdidae) from the Mascarene grass frog Ptychadena cf. mascareniensis (Amphibia: Ptychadenidae). A light and scanning electron microscopic studies.

    Science.gov (United States)

    Abdel-Gaber, Rewaida; Abdel-Ghaffar, Fathy; Kamel, Reem; Maher, Sherein; El Deeb, Nashwa; Al Quraishy, Saleh; Mehlhorn, Heinz

    2017-06-01

    The Mascarene grass frog Ptychadena cf. mascareniensis is a species of frog with a vast area of distribution in Africa. A total of 300 frog specimens were collected from different localities at El-Giza province, Egypt; then dissected and examined for the presence of parasitic infection. Only eighty six (28.66%) specimens were found to be naturally infected with nematode parasite. Seasonally, the prevalence of infection was reached its maximum value of 74.66% during summer and minimum values of 26.66% (20/75), 13.33% (10/75) during spring and autumn, respectively; while no records were observed during winter season. The morphology of the recovered parasite was studied by using light and scanning electron microscopy. The adult worm characterized by anterior extremity with small mouth opening being surrounded by three lips provided with four sub-median cephalic papillae and one pair of lateral amphids. Body measurements showed that male worms were smaller than females measuring 1.22-2.43 (2.21 ± 0.1) mm in length and 0.21-0.34 (0.29 ± 0.01) mm in width. Females measured 1.9-3.7 (2.8 ± 0.1) mm in length and 0.24-0.42 (0.38 ± 0.01) mm in width. Comparing the present parasite with other species of the same genus described previously, several similarities were observed. However, peculiar new characteristics such as the arrangement of plectanes and somatic papillae, the presence of gubernaculum, the position of nerve ring, excretory pore, and vulval opening make it reasonable belongs to the family Cosmocercidae and identified as Cosmocerca sp. In addition, the present study was the first report for occurrence of cosmocercid species from the Mascarene grass frog in Egypt.

  16. Plant litter effects on soil nutrient availability and vegetation dynamics: changes that occur when annual grasses invade shrub-steppe communities

    Science.gov (United States)

    Sheel Bansal; Roger L. Sheley; Bob Blank; Edward A. Vasquez

    2014-01-01

    Changes in the quantity and quality of plant litter occur in many ecosystems as they are invaded by exotic species, which impact soil nutrient cycling and plant community composition. Such changes in sagebrush-steppe communities are occurring with invasion of annual grasses (AG) into a perennial grass (PG) dominated system. We conducted a 5-year litter manipulation...

  17. Friends, family and social belonging as we age

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Aims: This study investigated if perceptions of social belonging in late adulthood are differentiated by the quality of family and friend relationships. Method:  The study consisted of two phases.  In Phase 1, 260 university staff and students, aged 18 to 75, completed an online survey investigating the quality of family and friend relationships and their association with social belonging.  In Phase 2, 88 older adults completed a refined print version of the survey.   Results:  Multiple regression was used to analyse the predictive ability of family and friend relationships on social belonging. In Phase 1, significant associations were found between both family and friend relationships and social belonging, with friendship yielding the strongest relationship.  Interestingly, in Phase 2 the association between quality of family and friend relationships and social belonging was mediated by age. Those aged 65 to 74 reported a significant relationship between friends and social belonging, which contrasted with those aged over 75.  A significant association between social belonging and family relationships was also found for the entire cohort aged over 65, while high quality friend relationships enhanced social belonging when family relationships were not strong. Conclusions: These results are tentative, but suggest that future research should consider the role that both friendships and family play in promoting social belonging in older adults.

  18. 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.

  19. Distribution, Diversity, and Long-Term Retention of Grass Short Interspersed Nuclear Elements (SINEs).

    Science.gov (United States)

    Mao, Hongliang; Wang, Hao

    2017-08-01

    Instances of highly conserved plant short interspersed nuclear element (SINE) families and their enrichment near genes have been well documented, but little is known about the general patterns of such conservation and enrichment and underlying mechanisms. Here, we perform a comprehensive investigation of the structure, distribution, and evolution of SINEs in the grass family by analyzing 14 grass and 5 other flowering plant genomes using comparative genomics methods. We identify 61 SINE families composed of 29,572 copies, in which 46 families are first described. We find that comparing with other grass TEs, grass SINEs show much higher level of conservation in terms of genomic retention: The origin of at least 26% families can be traced to early grass diversification and these families are among most abundant SINE families in 86% species. We find that these families show much higher level of enrichment near protein coding genes than families of relatively recent origin (51%:28%), and that 40% of all grass SINEs are near gene and the percentage is higher than other types of grass TEs. The pattern of enrichment suggests that differential removal of SINE copies in gene-poor regions plays an important role in shaping the genomic distribution of these elements. We also identify a sequence motif located at 3' SINE end which is shared in 17 families. In short, this study provides insights into structure and evolution of SINEs in the grass family. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. Predicting Dry Matter Composition of Clover Grass Leys Using Data Simulation and Camera-based Segmentation of Field Canopies into White Clover, Red Clover, Grass and Weeds

    DEFF Research Database (Denmark)

    Skovsen, Søren; Dyrmann, Mads; Eriksen, Jørgen

    2018-01-01

    species in the biomass. In our setup, we exploit the top-down canopy view of the clover grass ley to estimate the volumetric composition of the yield, and predict the composition of the dry matter of the forage. Using a deep learning approach, the canopy image is automatically pixel-wise segmented....... The biggest hindrance to training a fully convolutional deep neural network is the requirement of labeled data. Due to the complexity, the high number of leaves and high levels of occlusions in clover grass canopies, hand labeling the data requires roughly 20 hours of manual labor per image. The need...... for hundreds or thousands labeled training images renders this approach unfeasible. We have shown that implementation of image simulation of distinct clover grass fields can reduce the labeling task significantly. Investing less than 20 hours of labor, thousands of simulated images and corresponding labels can...

  1. Grass Biomethane for Agriculture and Energy

    DEFF Research Database (Denmark)

    Korres, N.E.; Thamsiriroj, T.; Smith, B.

    2011-01-01

    have advanced the role of grassland as a renewable source of energy in grass biomethane production with various environmental and socio-economic benefits. It is underlined that the essential question whether the gaseous biofuel meets the EU sustainability criteria of 60% greenhouse gas emission savings...... by 2020 can be met since savings up to 89.4% under various scenarios can be achieved. Grass biomethane production compared to other liquid biofuels either when these are produced by indigenous of imported feedstocks is very promising. Grass biomethane, given the mature and well known technology...

  2. 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.

  3. The second immunoglobulin class is commonly present in cartilaginous fish belonging to the order Rajiformes.

    Science.gov (United States)

    Kobayashi, K; Tomonaga, S

    1988-02-01

    Six species of cartilaginous fish distributed into four orders, Rajiformes (skates and guitarfishes), Myliobatiformes (rays), Heterodontiformes (sharks) and Carcharhiniformes (sharks), were investigated for the possible presence of a second class of immunoglobulin (Ig) other than IgM. Among those orders, fish belonging to the order Rajiformes were found to have a second Ig (IgR) with a non-covalently associated dimeric structure in which the H chain was different from that of IgM in mol. wt and antigenicity. Cartilaginous fish belonging to the other orders investigated had only one class of IgM.

  4. 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

  5. Use of ionizing radiation in grass breeding. I

    International Nuclear Information System (INIS)

    Indruch, I.; Svetlik, V.; Ligocki, J.

    1980-01-01

    Two subspecies of F. rubra occurring in natural localities of north-east Moravia (CSSR) in the Beskydy Mts. were used. In Festuca rubra L. ssp. genuina grandiflora (Hack.) 2n=8x=56, F. rubra represented a model species used for testing the effects of both acute and chronic gamma irradiation. In Festuca rubra L. ssp. vulgaris (Gaud.) Hay 2n=6x=42, new breeding was realized with success. The effects on important features of grasses were identical in both cases. The extension of combining abilities is especially important because it allows the production of forms less frequent in natural populations. (author)

  6. Phenology largely explains taller grass at successful nests in greater sage-grouse.

    Science.gov (United States)

    Smith, Joseph T; Tack, Jason D; Doherty, Kevin E; Allred, Brady W; Maestas, Jeremy D; Berkeley, Lorelle I; Dettenmaier, Seth J; Messmer, Terry A; Naugle, David E

    2018-01-01

    Much interest lies in the identification of manageable habitat variables that affect key vital rates for species of concern. For ground-nesting birds, vegetation surrounding the nest may play an important role in mediating nest success by providing concealment from predators. Height of grasses surrounding the nest is thought to be a driver of nest survival in greater sage-grouse ( Centrocercus urophasianus ; sage-grouse), a species that has experienced widespread population declines throughout their range. However, a growing body of the literature has found that widely used field methods can produce misleading inference on the relationship between grass height and nest success. Specifically, it has been demonstrated that measuring concealment following nest fate (failure or hatch) introduces a temporal bias whereby successful nests are measured later in the season, on average, than failed nests. This sampling bias can produce inference suggesting a positive effect of grass height on nest survival, though the relationship arises due to the confounding effect of plant phenology, not an effect on predation risk. To test the generality of this finding for sage-grouse, we reanalyzed existing datasets comprising >800 sage-grouse nests from three independent studies across the range where there was a positive relationship found between grass height and nest survival, including two using methods now known to be biased. Correcting for phenology produced equivocal relationships between grass height and sage-grouse nest survival. Viewed in total, evidence for a ubiquitous biological effect of grass height on sage-grouse nest success across time and space is lacking. In light of these findings, a reevaluation of land management guidelines emphasizing specific grass height targets to promote nest success may be merited.

  7. Improving our understanding of environmental controls on the distribution of C3 and C4 grasses.

    Science.gov (United States)

    Pau, Stephanie; Edwards, Erika J; Still, Christopher J

    2013-01-01

    A number of studies have demonstrated the ecological sorting of C3 and C4 grasses along temperature and moisture gradients. However, previous studies of C3 and C4 grass biogeography have often inadvertently compared species in different and relatively unrelated lineages, which are associated with different environmental settings and distinct adaptive traits. Such confounded comparisons of C3 and C4 grasses may bias our understanding of ecological sorting imposed strictly by photosynthetic pathway. Here, we used MaxEnt species distribution modeling in combination with satellite data to understand the functional diversity of C3 and C4 grasses by comparing both large clades and closely related sister taxa. Similar to previous work, we found that C4 grasses showed a preference for regions with higher temperatures and lower precipitation compared with grasses using the C3 pathway. However, air temperature differences were smaller (2 °C vs. 4 °C) and precipitation and % tree cover differences were larger (1783 mm vs. 755 mm, 21.3% vs. 7.7%, respectively) when comparing C3 and C4 grasses within the same clade vs. comparing all C4 and all C3 grasses (i.e., ignoring phylogenetic structure). These results were due to important differences in the environmental preferences of C3 BEP and PACMAD clades (the two main grass clades). Winter precipitation was found to be more important for understanding the distribution and environmental niche of C3 PACMADs in comparison with both C3 BEPs and C4 taxa, for which temperature was much more important. Results comparing closely related C3 -C4 sister taxa supported the patterns derived from our modeling of the larger clade groupings. Our findings, which are novel in comparing the distribution and niches of clades, demonstrate that the evolutionary history of taxa is important for understanding the functional diversity of C3 and C4 grasses, and should have implications for how grasslands will respond to global change. © 2012

  8. Pampas Grass - Orange Co. [ds351

    Data.gov (United States)

    California Natural Resource Agency — 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...

  9. Tree-grass interactions in savannas

    CSIR Research Space (South Africa)

    Scholes, RJ

    1997-01-01

    Full Text Available Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody and gramineous plants interact by many mechanisms, some negative (competition) and some positive (facilitation). The strength and sign...

  10. POTENTIALS OF AGRICULTURAL WASTE AND GRASSES IN ...

    African Journals Online (AJOL)

    Shima

    Potentials of some agricultural waste and grasses were investigated. ... to education, printing, publishing and ... technical form, paper is an aqueous deposit ..... Period of. Soaking. Overnight. Overnight. Overnight. Overnight. Overnight.

  11. Grasses for energy production: hydrological guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.L.

    2003-07-01

    This report provides hydrological guidelines for growers, land and water resource managers, environmental groups and other parties interested in utilising grasses for energy production. The aim of the report is to help interested parties decide if a location is suitable for planting energy grasses by considering whether potential hydrological impacts will have an adverse effect on crop productivity and yield. The guidelines consider: the water use of energy grasses compared with other crops; the factors governing water use; the water requirements for a productive crop; and the likely impacts on the availability and quantity of water. The report points out that there are still gaps in our knowledge of the processes controlling the water use and growth of energy grasses and notes that, in some situations, there will be considerable uncertainty in predictions of water use and the magnitude of the associated hydrological impacts.

  12. Imaging spectroscopy for characterisation of grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.

    2003-01-01

    Keywords: Imaging spectroscopy, imaging spectrometry, remote sensing, reflection, reflectance, grass sward, white clover, recognition, characterisation, ground cover, growth monitoring, stress detection, heterogeneity quantification

    The potential of imaging spectroscopy as a tool for

  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. Acculturative Stress and School Belonging among Latino Youth

    Science.gov (United States)

    Roche, Cathy; Kuperminc, Gabriel P.

    2012-01-01

    Dimensions of acculturative stress and their implications for school belonging and achievement were examined among 199 Latino middle-school students. The proposed model hypothesized that school belonging would mediate the association between acculturative stress dimensions and low school achievement. Eighty percent youth of the sample were…

  15. Migrant Rap in the Periphery: Performing Politics of Belonging

    Science.gov (United States)

    Leppänen, Sirpa; Westinen, Elina

    2017-01-01

    Focusing on a YouTube performance by an emergent Finnish Somali rapper and the audience responses it has generated, this paper looks at ways in which rap music engages with the issue of belonging. Drawing on recent theorizations of belonging as a multi-dimensional, contingent and fluid process, along with sociolinguistic work on globalization and…

  16. Belonging as a Guiding Principle in the Education of Adolescents

    Science.gov (United States)

    Allen, Kelly A.; Bowles, Terence

    2012-01-01

    Belonging has been shown to have a significant impact on a range of factors associated with wellbeing. These areas include life satisfaction, general wellbeing, clinical depression, cognitive performance, academic outcomes, and physical health. Belonging is an important aspect of psychological functioning. Schools offer unique opportunities for…

  17. Multiple Religious Belonging: Hermeneutical Challenges for Theology of Religions

    Directory of Open Access Journals (Sweden)

    Oostveen Daan F.

    2017-01-01

    Full Text Available The phenomenon of multiple religious belonging is studied from different perspectives, each of which reveals a different understanding of religion, religious diversity and religious belonging. This shows that the phenomenon of multiple religious belonging is challenging the applicability of these central notions in academic enquiry about religion. In this article, I present the different perspectives on multiple religious belonging in theology of religions and show how the understanding of some central scholarly notions is different. In Christian theology, the debate on multiple religious belonging is conducted between particularists, who focus on the uniqueness of religious traditions, and pluralists, who focus on the shared religious core of religious traditions. Both positions are criticized by feminist and post-colonial theologians. They believe that both particularists and pluralists focus too strongly on religious traditions and the boundaries between them. I argue that the hermeneutic study of multiple religious belonging could benefit from a more open understanding of religious traditions and religious boundaries, as proposed by these feminist and post-colonial scholars. In order to achieve this goal we could also benefit from a more intercultural approach to multiple religious belonging in order to understand religious belonging in a nonexclusive way.

  18. Social inhibition sense of belonging and vulnerability to internalizing problems

    NARCIS (Netherlands)

    de Moor, E.L.; Denollet, J.; Laceulle, O.M.

    2018-01-01

    Background The aim of this study was to provide a conceptual test of how social inhibition, sense of belonging and internalizing problems are related, and whether sense of belonging moderates or mediates the relation between social inhibition and internalizing problems. Methods Data were used from

  19. How the Host Nation's Boundary Drawing Affects Immigrants' Belonging

    DEFF Research Database (Denmark)

    Simonsen, Kristina Bakkær

    2016-01-01

    Across Western democracies, the place for newcomers in the host society is debated, involving often a questioning of immigrants’ belonging to their new nation. This article argues that immigrants’ feeling of host national belonging depends on how the host nation imagines its community and its...

  20. Social Class and Belonging: Implications for Graduate Students' Career Aspirations

    Science.gov (United States)

    Ostrove, Joan M.; Stewart, Abigail J.; Curtin, Nicola L.

    2011-01-01

    We examined the role that social class background plays in graduate students' career goals. Class background was significantly related to the extent to which students struggled financially in graduate school, which related to their sense of belonging in graduate school. Sense of belonging related to academic self-concept, which predicted students'…

  1. Hybrid Citizenship: Latina Youth and the Politics of Belonging

    Science.gov (United States)

    Bondy, Jennifer M.

    2015-01-01

    Drawing from interview data collected from high school students in Broward County, Florida, this article explores how eight adolescent Latinas understand citizenship and belonging vis-à-vis circulating images and discourses on Latina/o immigration, immigrant, and Latina. The author examines Latina youths' citizenship identities and belonging using…

  2. Detrimental and Neutral Effects of a Wild Grass-Fungal Endophyte Symbiotum on Insect Preference and Performance

    OpenAIRE

    Clement, Stephen L.; Hu, Jinguo; Stewart, Alan V.; Wang, Bingrui; Elberson, Leslie R.

    2011-01-01

    Seed-borne Epichloë/Neotyphodium Glenn, Bacon, Hanlin (Ascomycota: Hypocreales: Clavicipitaceae) fungal endophytes in temperate grasses can provide protection against insect attack with the degree of host resistance related to the grass—endophyte symbiotum and the insect species involved in an interaction. Few experimental studies with wild grass—endophyte symbiota, compared to endophyte-infected agricultural grasses, have tested for anti-insect benefits, let alone for resistance against more...

  3. 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.

  4. Interacting effects of grass height and herbivores on the establishment of an encroaching savanna shrub

    NARCIS (Netherlands)

    Hagenah, N.; Munkert, H.; Gerhardt, K.; Olff, H.

    2009-01-01

    Shrub encroachment is a widely observed problem in Southern African savannas. Although the effects of herbivory and grass height on woody species recruitment have been studied individually, little information exists about how these factors interact. In this study seeds and seedlings of the

  5. Earthworm activity and decomposition of 14C-labelled grass root systems

    NARCIS (Netherlands)

    Uyl, A.; Didden, W.A.M.; Marinussen, J.

    2002-01-01

    Decomposition of 14C-labelled root systems of the grass species Holcus lanatus and Festuca ovina, representative of mesotrophic and oligotrophic situations, respectively, was monitored during 14 months under field conditions in the presence or absence of earthworms (Lumbricus rubellus). During the

  6. Community structure affects annual grass weed invasion during restoration of a shrub-steppe ecosystem

    Science.gov (United States)

    Phil S. Allen; Susan E. Meyer

    2014-01-01

    Ecological restoration of shrub-steppe communities in the western United States is often hampered by invasion of exotic annual grasses during the process. An important question is how to create restored communities that can better resist reinvasion by these weeds. One hypothesis is that communities comprised of species that are functionally similar to the invader will...

  7. Leaf silicification in grasses - a review. | P.J. | African Journal of ...

    African Journals Online (AJOL)

    Silica is absorbed from the soil by many grasses in an active or passive manner depending upon depending upon the species involved. It is carried upwards in the transpiration stream and deposited throughout the plant where it polymerizes to form amorphous silica gel. Deposition appears to be a passive process but ...

  8. 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

  9. It Feels Good to Learn Where I Belong: School Belonging, Academic Emotions, and Academic Achievement in Adolescents

    Science.gov (United States)

    Lam, Un Fong; Chen, Wei-Wen; Zhang, Jingqi; Liang, Ting

    2015-01-01

    This study examined the relationships between school belonging, academic emotions, and academic achievement in Macau adolescents. A survey of 406 junior high school students in Macau was used to collect information on the extent to which these students felt accepted and respected in their schools (school belonging), the emotions they experienced…

  10. Treatment with grass allergen peptides improves symptoms of grass pollen-induced allergic rhinoconjunctivitis.

    Science.gov (United States)

    Ellis, Anne K; Frankish, Charles W; O'Hehir, Robyn E; Armstrong, Kristen; Steacy, Lisa; Larché, Mark; Hafner, Roderick P

    2017-08-01

    Synthetic peptide immunoregulatory epitopes are a new class of immunotherapy to treat allergic rhinoconjunctivitis (ARC). Grass allergen peptides, comprising 7 synthetic T-cell epitopes derived from Cyn d 1, Lol p 5, Dac g 5, Hol l 5, and Phl p 5, is investigated for treatment of grass pollen-induced ARC. We sought to evaluate the efficacy, safety, and tolerability of intradermally administered grass allergen peptides. A multicenter, randomized, double-blind, placebo-controlled study evaluated 3 regimens of grass allergen peptides versus placebo in patients with grass pollen-induced allergy (18-65 years). After a 4-day baseline challenge to rye grass in the environmental exposure unit (EEU), subjects were randomized to receive grass allergen peptides at 6 nmol at 2-week intervals for a total of 8 doses (8x6Q2W), grass allergen peptides at 12 nmol at 4-week intervals for a total of 4 doses (4x12Q4W), or grass allergen peptides at 12 nmol at 2-week intervals for a total of 8 doses (8x12Q2W) or placebo and treated before the grass pollen season. The primary efficacy end point was change from baseline in total rhinoconjunctivitis symptom score across days 2 to 4 of a 4-day posttreatment challenge (PTC) in the EEU after the grass pollen season. Secondary efficacy end points and safety were also assessed. Two hundred eighty-two subjects were randomized. Significantly greater improvement (reduction of total rhinoconjunctivitis symptom score from baseline to PTC) occurred across days 2 to 4 with grass allergen peptide 8x6Q2W versus placebo (-5.4 vs -3.8, respectively; P = .0346). Greater improvement at PTC also occurred for grass allergen peptide 8x6Q2W versus placebo (P = .0403) in patients with more symptomatic ARC. No safety signals were detected. Grass allergen peptide 8x6Q2W significantly improved ARC symptoms after rye grass allergen challenge in an EEU with an acceptable safety profile. Copyright © 2017 American Academy of Allergy, Asthma & Immunology

  11. Effect of grazing system and the grass species on the pasture infestation and on the nematode gastrointestinal parasitism in beef cattle Efeito de sistema de pastejo e de espécies forrageiras na contaminação da pastagem e no parasitismo por nematóides gastrintestinais em bovinos de corte

    Directory of Open Access Journals (Sweden)

    Ivo Bianchin

    2007-12-01

    Full Text Available During two years, the infestation of infecting larvae on grazing grass and the level of gastrointestinal nematodes in beef cattle, in the region of the Brazilian Cerrado, were monitored. In the first study, parasitological variables were investigated on pasture of Panicum maximum cv Mombaça, under continuous or rotational grazing, with four (36 resting days and 12 occupation days and ten paddocks (36 resting days and 4 occupation days. In the second study, these variables were evaluated with different forage species (Panicum maximum cv Mombaça, Braquiaria brizantha cv Marandu and Cynodon spp. (Tifton 85, under rotational grazing on eight paddocks (28 resting days and 4 occupation days. In the first study, and only in the first year, the infestation of pasture with infecting larvae was lower (P<0.05 in the rotation system with ten divisions. For the remaining observations of both studies, there were no significant effects of grazing systems and grass species on the fecal egg count and the number of infecting larvae in the pasture. These results indicated that, in the conditions the studies were carried out, the pasture resting for 36 days was insufficient to decrease the EPF and the infestation of pasture.Durante dois anos, acompanhou-se a infestação das pastagens por larvas infectantes e o nível de parasitismo por nematódeos gastrintestinais em bovinos de corte, na região do Cerrado. No primeiro estudo as variáveis parasitológicas foram acompanhadas em pastagens de Panicum maximum cv Mombaça, submetidas ao pastejo continuo e ao rotacionado, com 4 (36 dias de descanso e 12 dias de ocupação e 10 piquetes (36 dias de descanso e 4 dias de ocupação. No segundo estudo, essas variáveis foram avaliadas com diferentes espécies forrageiras (Panicum maximum cv Mombaça, Braquiaria brizantha cv Marandu e Cynodon spp (Tifton 85, sob pastejo rotacionado em 8 piquetes (28 dias de descanso e 4 dias de ocupação. No primeiro estudo, e apenas no

  12. Disentangling Memories. Complex (Be)longings and Social Categories

    DEFF Research Database (Denmark)

    Pedersen, Chistina Hee; Frølunde, Lisbeth

    2013-01-01

    This presentation analyses the complex workings of social categories in constructions of (be)longing in memories of young university students in Bolivia and Peru. In a methodology course the participants explored how socio economic and socio cultural differences had affected the lives...... belonging to a specific social or racial group. (Be)longing to a specific gendered and radicalised body constitutes in the analysis of these stories an excellent “location,” from which to analyse how socio/cultural and socio/economic categories like class, nationality and age intersect with one another...... to produce insights and consciousness about the socio-cultural impact of sense making processes....

  13. Nutritional value of cabbage and kikuyu grass as food for grass carp ...

    African Journals Online (AJOL)

    and digestibility coefficients were obtained for the protein, fibre, ash and fat contents of both ... Cabbage is a superior feed compared to grass for raising grass carp and a suitable low-cost alternative ... Materials and Methods ... from jumping out and was fitted with an air lift under- .... In: Aquatic weeds in South East Asia.

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

    Directory of Open Access Journals (Sweden)

    Ermeng Yu

    2014-01-01

    Full Text Available 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 carp. Gene ontology (GO analysis revealed 30 GOs of differentially expressed genes in crisp grass carp. And strong correlation with muscle firmness increase of crisp grass carp was found for these genes from differentiation of muscle fibers and deposition of ECM, and also glycolysis/gluconeogenesis pathway and calcium metabolism may contribute to muscle firmness increase. In addition, a number of genes with unknown functions may be related to muscle firmness, and these genes are still further explored. Overall, these results had been demonstrated to play important roles in clarifying the molecular mechanism of muscle firmness increase in crisp grass carp.

  15. Different techniques to study rumen fermentation characteristics of maturing grass and grass silage

    NARCIS (Netherlands)

    Cone, J.W.; Gelder, van A.H.; Soliman, I.A.; Visser, de H.; Vuuren, van A.M.

    1999-01-01

    Grass samples were harvested during the 1993 growing season after a precut on April 27, 1993 and were stored frozen or left to ensile in 30-L buckets. Effects on chemical composition and fermentation kinetics of the maturation of the grass and of ensiling were investigated. Chemical composition and

  16. 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

  17. Post-ruminal digestibility of crude protein from grass and grass silages in cows

    NARCIS (Netherlands)

    Cone, J.W.; Gelder, van A.H.; Mathijssen-Kamman, A.A.; Hindle, V.A.

    2006-01-01

    Grass samples were grown on a clay or sandy soil, fertilised with 150 or 300 kg N/ha per year, and harvested on different days during two consecutive growing seasons. The grass samples were stored frozen or ensiled after wilting to approximately 250 or 450 g DM/kg. The recoveries of crude protein

  18. Confronting species distribution model predictions with species functional traits.

    Science.gov (United States)

    Wittmann, Marion E; Barnes, Matthew A; Jerde, Christopher L; Jones, Lisa A; Lodge, David M

    2016-02-01

    Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day(-1). Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = -0.26, 95% CI (-0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.

  19. Germination sensitivities to water potential among co-existing C3 and C4 grasses of cool semi-arid prairie grasslands.

    Science.gov (United States)

    Mollard, F P O; Naeth, M A

    2015-03-01

    An untested theory states that C4 grass seeds could germinate under lower water potentials (Ψ) than C3 grass seeds. We used hydrotime modelling to study seed water relations of C4 and C3 Canadian prairie grasses to address Ψ divergent sensitivities and germination strategies along a risk-spreading continuum of responses to limited water. C4 grasses were Bouteloua gracilis, Calamovilfa longifolia and Schizachyrium scoparium; C3 grasses were Bromus carinatus, Elymus trachycaulus, Festuca hallii and Koeleria macrantha. Hydrotime parameters were obtained after incubation of non-dormant seeds under different Ψ PEG 6000 solutions. A t-test between C3 and C4 grasses did not find statistical differences in population mean base Ψ (Ψb (50)). We found idiosyncratic responses of C4 grasses along the risk-spreading continuum. B. gracilis showed a risk-taker strategy of a species able to quickly germinate in a dry soil due to its low Ψb (50) and hydrotime (θH ). The high Ψb (50) of S. scoparium indicates it follows the risk-averse strategy so it can only germinate in wet soils. C. longifolia showed an intermediate strategy: the lowest Ψb (50) yet the highest θH . K. macrantha, a C3 grass which thrives in dry habitats, had the highest Ψb (50), suggesting a risk-averse strategy for a C3 species. Other C3 species showed intermediate germination patterns in response to Ψ relative to C4 species. Our results indicate that grasses display germination sensitivities to Ψ across the risk-spreading continuum of responses. Thus seed water relations may be poor predictors to explain differential recruitment and distribution of C3 and C4 grasses in the Canadian prairies. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. 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.

  1. 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.

  2. Herbaceous Legume Encroachment Reduces Grass Productivity and Density in Arid Rangelands.

    Directory of Open Access Journals (Sweden)

    Thomas C Wagner

    Full Text Available Worldwide savannas and arid grasslands are mainly used for livestock grazing, providing livelihood to over a billion people. While normally dominated by perennial C4 grasses, these rangelands are increasingly affected by the massive spread of native, mainly woody legumes. The consequences are often a repression of grass cover and productivity, leading to a reduced carrying capacity. While such encroachment by woody plants has been extensively researched, studies on similar processes involving herbaceous species are rare. We studied the impact of a sustained and massive spread of the native herbaceous legume Crotalaria podocarpa in Namibia's escarpment region on the locally dominant fodder grasses Stipagrostis ciliata and Stipagrostis uniplumis. We measured tussock densities, biomass production of individual tussocks and tussock dormancy state of Stipagrostis on ten 10 m x 10 m plots affected and ten similarly-sized plots unaffected by C. podocarpa over eight consecutive years and under different seasonal rainfalls and estimated the potential relative productivity of the land. We found the percentage of active Stipagrostis tussocks and the biomass production of individual tussocks to increase asymptotically with higher seasonal rainfall reaching a maximum around 300 mm while the land's relative productivity under average local rainfall conditions reached only 40% of its potential. Crotalaria podocarpa encroachment had no effect on the proportion of productive grass tussocks, but reduced he productivity of individual Stipagrostis tussocks by a third. This effect of C. podocarpa on grass productivity was immediate and direct and was not compensated for by above-average rainfall. Besides this immediate effect, over time, the density of grass tussocks declined by more than 50% in areas encroached by C. podocarpa further and lastingly reducing the lands carrying capacity. The effects of C. podocarpa on grass productivity hereby resemble those of woody

  3. Identification of Recent Bats belonging to the Rhinolophidae by the Humeral Characters

    OpenAIRE

    Yoon, Myung Hee; Uchida, Teruaki; 内田, 照章

    1983-01-01

    Humeral characters of eleven recent species and one subspecies belonging to three genera of the Rhinolophidae including two subfamilies were described. A key provides for their identification as well as the identification of the fossil bats found on the Akiyoshi-dai Plateau. Further, we discussed differences in the adaptability for flight of the bats not only within each taxon of the family but also between the phylogenetically less advanced Rhinolophidae and the more advanced Vespertilionida...

  4. Critical Taxonomic Appraisal of Some Taxa of Pedicularis from Indian Himalayas Belonging to Section Siphonanthae

    Directory of Open Access Journals (Sweden)

    Arti Garg

    2009-06-01

    Full Text Available The existing confusion on the taxonomic status of five taxa of Pedicularis viz. P. punctata Decne, P. siphonantha D. Don, P. hookeriana Wall. ex Benth., P. megalantha D. Don and P. hoffmeisteri Kl. ex Kl. & Garcke is resolved on the basis of critical morphological study. These taxa belong to section Siphonanthae, subgenus Longirostres. Pennell’s view of segregating these taxa into distinct species is defended and upheld.

  5. Weather and plant age affect the levels of steroidal saponin and Pithomyces chartarum spores in Brachiaria grass

    Science.gov (United States)

    Brachiaria species are cultivated worldwide in tropical and subtropical climates as the main forage source for ruminants. Numerous tropical and warm-season grasses cause hepatogenous photosensitization, among them several species of Brachiaria. Steroidal saponins present in these plants may be respo...

  6. Common garden comparisons of reproductive, forage and weed suppression potential of rangeland rehabilitation grasses of the Great Basin

    Science.gov (United States)

    Common garden experiments are a means to remove environmental effects. Using 8 species of perennial rangeland grasses, we established a common garden (3 reps x28 plants = 84 plants/species). We found that ‘Hycrest’ crested wheatgrass (Agropyron cristatum) and bluebunch wheatgrass (Pseudoroegneria sp...

  7. New Claviceps species from warm-season grasses

    Czech Academy of Sciences Publication Activity Database

    Pažoutová, Sylvie; Odvody, G.; Frederickson, D.E.; Chudíčková, Milada; Olšovská, Jana; Kolařík, Miroslav

    2011-01-01

    Roč. 49, č. 1 (2011), s. 145-165 ISSN 1560-2745 R&D Projects: GA ČR GA206/97/0611 Institutional research plan: CEZ:AV0Z50200510 Keywords : Ascomycota * Taxonomy * Phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 4.769, year: 2011

  8. Plant Growth and Phosphorus Uptake of Three Riparian Grass Species

    Science.gov (United States)

    Riparian buffers can significantly reduce sediment-bound phosphorus (P) entering surface water, but control of dissolved P inputs is more challenging. Because plant roots remove P from soil solution, it follows that plant uptake will reduce dissolved P losses. We evaluated P uptake of smooth bromegr...

  9. An African grassland responds similarly to long-term fertilization to the Park Grass experiment.

    Directory of Open Access Journals (Sweden)

    David Ward

    Full Text Available We compared the results of a long-term (65 years experiment in a South African grassland with the world's longest-running ecological experiment, the Park Grass study at Rothamsted, U.K. The climate is warm and humid in South Africa and cool and temperate in England. The African grassland has been fertilized with two forms of nitrogen applied at four levels, phosphorus and lime in a crossed design in 96 plots. In 1951, about 84% of plant cover consisted of Themeda triandra, Tristachya leucothrix and Setaria nigrirostris. Currently, the dominant species are Panicum maximum, Setaria sphacelata and Eragrostis curvula, making up 71% of total biomass. As in the Park Grass experiment, we found a significant (additive interaction effect on ANPP of nitrogen and phosphorus, and a (marginally significant negative correlation between ANPP and species richness. Unlike the Park Grass experiment, there was no correlation between ANPP and species richness when pH was included as a covariate. There was also a significant negative effect of nitrogen amount and nitrogen form and a positive effect of lime on species richness and species diversity. Soil pH had an important effect on species richness. Liming was insufficient to balance the negative effects on species richness of nitrogen fertilization. There was a significant effect of pH on biomass of three abundant species. There were also significant effects of light on the biomass of four species, with only Panicum maximum having a negative response to light. In all of the abundant species, adding total species richness and ANPP to the model increased the amount of variance explained. The biomass of Eragrostis curvula and P. maximum were negatively correlated with species richness while three other abundant species increased with species richness, suggesting that competition and facilitation were active. Consistent with the results from the Park Grass and other long-term fertilization experiments of grasslands

  10. 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.

  11. Immunochemical Analysis of Paxilline and Ergot Alkaloid Mycotoxins in Grass Seeds and Plants.

    Science.gov (United States)

    Bauer, Julia I; Gross, Madeleine; Cramer, Benedikt; Humpf, Hans-Ulrich; Hamscher, Gerd; Usleber, Ewald

    2018-01-10

    Limited availability of toxin standards for lolitrem B and ergovaline impedes routine control of grasses for endophyte toxins. This study aimed at assessing the applicability of an enzyme immunoassay (EIA) for the indole-diterpene mycotoxin paxilline, in combination with a generic EIA for ergot alkaloids, as alternative parameters for screening purposes. Analysis of grass seeds and model pastures of four different grass species showed that both EIAs yielded highly positive results for paxilline and ergot alkaloids in perennial ryegrass seeds. Furthermore, evidence for natural occurrence of paxilline in grass in Germany was obtained. High performance liquid chromatography-tandem mass spectrometry analysis qualitatively confirmed the paxilline EIA results but showed that paxilline analogues 1'-O-acetylpaxilline and 13-desoxypaxilline were the predominant compounds in seeds and grass. In the absence of easily accessible reference standards for specific analysis of some major endophyte toxins, analysis of paxilline and ergot alkaloids by EIA may be suitable substitute parameters. The major advantage of this approach is its ease of use and speed, providing an analytical tool which could enhance routine screening for endophyte toxins in pasture.

  12. Current Models for Transcriptional Regulation of Secondary Cell Wall Biosynthesis in Grasses

    Directory of Open Access Journals (Sweden)

    Xiaolan Rao

    2018-04-01

    Full Text Available Secondary cell walls mediate many crucial biological processes in plants including mechanical support, water and nutrient transport and stress management. They also provide an abundant resource of renewable feed, fiber, and fuel. The grass family contains the most important food, forage, and biofuel crops. Understanding the regulatory mechanism of secondary wall formation in grasses is necessary for exploiting these plants for agriculture and industry. Previous research has established a detailed model of the secondary wall regulatory network in the dicot model species Arabidopsis thaliana. Grasses, branching off from the dicot ancestor 140–150 million years ago, display distinct cell wall morphology and composition, suggesting potential for a different secondary wall regulation program from that established for dicots. Recently, combined application of molecular, genetic and bioinformatics approaches have revealed more transcription factors involved in secondary cell wall biosynthesis in grasses. Compared with the dicots, grasses exhibit a relatively conserved but nevertheless divergent transcriptional regulatory program to activate their secondary cell wall development and to coordinate secondary wall biosynthesis with other physiological processes.

  13. 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, Si-Fa

    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.

  14. 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.

  15. Potential of grass seed production for new lawns

    Directory of Open Access Journals (Sweden)

    Josiane Vargas de Oliveira Maximino

    2017-07-01

    Full Text Available The Paspalum and Axonopus genera are among the main warm season grasses used for lawns. The seed propagation contributes to the decrease of the cost of establishment, besides maintaining the exact characteristics of the mother plant genotype, because they are apomictic species. The objective of this work was to evaluate the seed production potential of seventeen grass accesses of the species Paspalum notatum, P. lepton, P. lividum and Axonopus parodii. The experiment was conducted at Capão do Leão, Rio Grande do Sul State, Brazil, in a randomized block design, with four replications. The evaluated variables were: number of inflorescences per area, number of florets per inflorescence and seed production potential (SPP. In order to measure the seed production potential of the accesses, the equation proposed is: SPP = number of florets per inflorescence x number of inflorescences per m2 . There were year, access and interaction between years and accesses effect for the traits number of inflorescences per area and seed production potential. For the number of florets per inflorescence, there was no year effect. Potential production for the 2013/2014 harvest, ranged from 19,152.00 to 135,062.70 seeds m- ², with PN 09 of the P. notatum species standing out. In the 2014/2015 harvest, the seed production potential ranged from 9,973.75 to 81,536.75 seeds m- ², highlighting the access PN 11 of the species P. notatum. The accesses PN 11, PN 09, PN 10 and AP 01 were in the top third of the seed production potential ranking in the two harvests, and “grama-batatais” was in the lower third. There is genotype-environment interaction for all characteristics evaluated. However, there are accesses that show seed production potential consistently superior to the “grama-batatais” control, and have a greater potential for exploitation in the establishment of lawns by seeds.

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

    Directory of Open Access Journals (Sweden)

    Carolina Bremm

    Full Text Available 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.

  17. Dynamics of a grassland ecosystem: botanical equilibrium in the Park Grass Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Silvertown, J

    1980-01-01

    The published results of the Park Grass Experiment (PGE), begun in 1856, provide up to 30 yr of annual data which may be used to determine whether the botanical composition of these grasslands was at equilibrium. Data covering a period exceeding 80 yr are available to test for relationships between hay yield (biomass), species diversity, species number and time. Species diversity and species number show negative relationships with plot biomass and with pH. These relationships were constant over time. The effects of biomass and pH on species number and species diversity were additive. Analysis of the flora of nine plots, each divided into grasses, legumes and a miscellaneous component showed that these components were at equilibrium. The effect of various endogenous factors on this botanical equilibrium was examined. No regular or irregular cycles of component biomass operating between years were detected and it is inferred that populations were regulated by processes operating within individual years. The biomasses of all three components were positively correlated within an unfertilized plot but the floristic components of plots receiving a fertilizer treatment showed few within-plot correlations. By contrast between-plot correlations of components were common for all plots with the exception of those receiving nitrogen fertilizer. The mechanisms of population regulation which maintained the park grass ecosystem at equilibrium are discussed and tests for these are proposed.

  18. Genetic resources of perennial forage grasses in Serbia: Current state, broadening and evaluation

    Directory of Open Access Journals (Sweden)

    Sokolović Dejan

    2017-01-01

    Full Text Available Due to historical background of vegetation development, geographical position, climate and relief, Serbia represents one of the 158 world biodiversity centres, based upon the number of plant species and territory size (biodiversity index 0.72. Large areas in Serbia are under natural grasslands and pastures, composed of forage grass species, and important as source of natural plant genetic diversity and germplasm for breeding. These eco-systems represent basic prerequisites for sustainable forage production, but very low potential of them is utilized and genetic resources are not protected. Family Poaceae is present in Serbia flora with 70 genera and among them from the aspect of forage production and quality, the most important are perennial Festuca, Lolium, Dactylis, Phleum, Bromus, Arrhenatherum, Poa and Agrostis species. Most of these grasses have been bred in Serbia and lot of cultivars were released. These cultivars contain autochthonous Serbian material and represent great and important resource of genetic variability. Therefore, collecting of new samples which are acclimatised to local eco-geographical conditions and including them in plant ex situ gene bank is of exceptional importance for further utilization in different plant breeding programmes as well as genetic resources protection. These autochthonous populations have natural variability and very often have satisfactory yielding performance in comparison with introduced cultivars, which referred them for direct phenotypic selection for cultivars release. Broadening of forage grasses genotypes collection is permanent objective of Serbian scientists. Collected accessions are being characterized and evaluated for important phenological, morphological and agronomical traits. In this paper genetic resources of forage grass species, their diversity and potentials, state of the grasses gene banks, as well as possibility for breeding of new cultivars has been analysed.

  19. 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.

  20. Biogas and Methane Yield from Rye Grass

    Directory of Open Access Journals (Sweden)

    Tomáš Vítěz

    2015-01-01

    Full Text Available Biogas production in the Czech Republic has expanded substantially, including marginal regions for maize cultivation. Therefore, there are increasingly sought materials that could partially replace maize silage, as a basic feedstock, while secure both biogas production and its quality.Two samples of rye grass (Lolium multiflorum var. westerwoldicum silage with different solids content 21% and 15% were measured for biogas and methane yield. Rye grass silage with solid content of 15% reached an average specific biogas yield 0.431 m3·kg−1 of organic dry matter and an average specific methane yield 0.249 m3·kg−1 of organic dry matter. Rye grass silage with solid content 21% reached an average specific biogas yield 0.654 m3·kg−1 of organic dry matter and an average specific methane yield 0.399 m3·kg−1 of organic dry matter.

  1. Rehabilitation experiment by phytoremediation using lawn grass

    International Nuclear Information System (INIS)

    2012-08-01

    Measures against environmental contamination by radioactive materials originated from the Fukushima Nuclear Accident (May, 2011), are being conducted in Fukushima and surrounding prefectures. Regarding to the measures, a phytoremediation experiment with several types of lawn grasses in a field scale have been carried out. Lawn grasses are generally characterized by shallow rhizosphere, high density and root mat formation. Decontamination effectiveness of radioactive cesium by plant uptake and by sod removing was investigated. As a result, the range of decontamination factors by plant uptake was below than 1% because of low transfer rate form soil to plant. On the other hand, maximum decontamination factor by sod removing reached about 100%. Decontamination activities with various methods will be implemented according to the national decontamination policy and related plans in each municipality. The phytoremediation method with lawn grass would be applicable in limited circumstances. (author)

  2. Relationship between the Al resistance of grasses and their adaptation to an infertile habitat.

    Science.gov (United States)

    Poozesh, Vahid; Cruz, Pablo; Choler, Philippe; Bertoni, Georges

    2007-05-01

    Original data on Al resistance, relative growth rate and leaf traits of five European grasses as well as literature data on Al resistance, habitat preference and traits of grasses were considered to determine whether (a) Al resistance is correlated to a growth conservative strategy and (b) species occurrence could be useful to assess Al toxicity in meadows on acid soils. The Al resistance of 15 species was represented by the Al activity in nutrient solution that resulted in a 50 % decrease in root length, [Al(3+)](50), or, for published values, in root or plant biomass. The correlations between Al resistance and acidity or nitrogen indices and the correlation between Al resistance and selected traits (relative growth rate, leaf dry matter content, specific leaf area and leaf thickness) were calculated. Principal component analysis was used for the characterization of the relationships between Al resistance and measured traits. The [Al(3+)](50) values of the resistant species Molinia caerulea and Sieglingia decumbens were 13 and 26 microm [Al(3+)](50), respectively. The known Al resistance of 15 species that were mainly of the intermediate strategy competitor-stress tolerator-ruderal (C-S-R) type and of the S type was correlated with Ellenberg's nitrogen and acidity indices. For the whole set of species, the correlation between Al resistance and traits was not significant. The Al resistance of the C-S-R species was variable and independent of their traits. S-type species, adapted to acid soils and with traits of conservative strategy, displayed Al resistance. The large difference in Al resistance between grasses may help assess Al soil toxicity by using the abundance of grasses.

  3. Genetic sorting of subordinate species in grassland modulated by intraspecific variation in dominant species.

    Directory of Open Access Journals (Sweden)

    Danny J Gustafson

    Full Text Available Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (Sorghastrum nutans and two subordinate species (Chamaecrista fasciculata, Silphium integrifolium, during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of S. nutans, C. fasciculata, and S. integrifolium and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.

  4. Sox genes in grass carp (Ctenopharyngodon idella) with their implications for genome duplication and evolution

    OpenAIRE

    Zhong , Lei; Yu , Xiaomu; Tong , Jingou

    2006-01-01

    Abstract The Sox gene family is found in a broad range of animal taxa and encodes important gene regulatory proteins involved in a variety of developmental processes. We have obtained clones representing the HMG boxes of twelve Sox genes from grass carp (Ctenopharyngodon idella), one of the four major domestic carps in China. The cloned Sox genes belong to group B1, B2 and C. Our analyses show that whereas the human genome contains a single copy of Sox4, Sox11 and Sox14, each of these genes h...

  5. Assessment of some macromineral concentration of a grass/ legume ...

    African Journals Online (AJOL)

    Assessment of some macromineral concentration of a grass/ legume sward in ... Bulletin of Animal Health and Production in Africa ... The study aimed to determine the concentration of some macromineral elements in the grass/legume pasture ...

  6. Modelling of excess noise attnuation by grass and forest | Onuu ...

    African Journals Online (AJOL)

    , guinea grass (panicum maximum) and forest which comprises iroko (milicia ezcelea) and white afara (terminalia superba) trees in the ratio of 2:1 approximately. Excess noise attenuation spectra have been plotted for the grass and forest for ...

  7. Photosynthetic light response of the C4 grasses Brachiaria brizantha and B. humidicola under shade

    Directory of Open Access Journals (Sweden)

    Dias-Filho Moacyr Bernardino

    2002-01-01

    Full Text Available Forage grasses in tropical pastures can be subjected to considerable diurnal and seasonal reductions in available light. To evaluate the physiological behavior of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola to low light, the photosynthetic light response and chlorophyll contents of these species were compared for plants grown outdoors, on natural soil, in pots, in full sunlight and those shaded to 30 % of full sunlight, over a 30-day period. Both species showed the ability to adjust their photosynthetic behavior in response to shade. Photosynthetic capacity and light compensation point were lower for shade plants of both species, while apparent quantum yield was unaffected by the light regime. Dark respiration and chlorophyll a:b ratio were significantly reduced by shading only in B. humidicola. B. humidicola could be relatively more adapted to succeed, at least temporarily, in light-limited environments.

  8. 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.

  9. 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

    2013-11-07

    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.

  10. 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.

  11. Nitrogen washing from C3 and C4 cover grasses residues by rain

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2010-12-01

    Full Text Available Crop species with the C4 photosynthetic pathway are more efficient in assimilating N than C3 plants, which results in different N amounts prone to be washed from its straw by rain water. Such differences may affect N recycling in agricultural systems where these species are grown as cover crops. In this experiment, phytomass production and N leaching from the straw of grasses with different photosynthetic pathways were studied in response to N application. Pearl millet (Pennisetum glaucum and congo grass (Brachiaria ruziziensis with the C4 photosynthetic pathway, and black oat (Avena Strigosa and triticale (X Triticosecale, with the C3 photosynthetic pathway, were grown for 47 days. After determining dry matter yields and N and C contents, a 30 mm rainfall was simulated over 8 t ha-1 of dry matter of each plant residue and the leached amounts of ammonium and nitrate were determined. C4 grasses responded to higher fertilizer rates, whereas N contents in plant tissue were lower. The amount of N leached from C4 grass residues was lower, probably because the C/N ratio is higher and N is more tightly bound to organic compounds. When planning a crop rotation system it is important to take into account the difference in N release of different plant residues which may affect N nutrition of the subsequent crop.

  12. Homegrown religious radicalization and the quest for belonging

    DEFF Research Database (Denmark)

    Khawaja, Iram

    this seemingly religious radicalization, from the point of view of the youngsters, by drawing on a study of young Muslims in religious communities in Copenhagen and combining it with existing blogs, twitter profiles etc. of youngsters sympathizing with Islamic radicalized movements. What are the youngsters...... framework based on a focus on belonging, self-construction and the sense of community will be proposed. The framework will be utilized in an analysis of narratives from youngsters who have chosen a radicalized path in life. The paper will shed light on how the sense of and yearning for belonging...

  13. Notes on Alien Bromus Grasses in Taiwan

    Directory of Open Access Journals (Sweden)

    Ming-Jer Jung

    2006-06-01

    Full Text Available Bromus carinatus Hook. & Arn., Bromus hordeaceus L., Bromus pubescens Muhl. ex Willd. and Bromus secalinus L. were recently found at middle elevations of southern and central Taiwan, respectively. We present taxonomic treatments, distribution map, and line-drawings of these introduced alien brome grasses.

  14. Notes on the nomenclature of some grasses

    NARCIS (Netherlands)

    Henrard, J.Th.

    1941-01-01

    In a former article 1) many new combinations and critical observations were published on various grasses all over the world. New investigations in critical genera together with the study of the existing literature made it necessary to accept various other arrangements in this important family. The

  15. Grass Pollen Pollution from Biofuels Farming

    Czech Academy of Sciences Publication Activity Database

    Ratajová, A.; Tříska, Jan; Vrchotová, Naděžda; Kolář, L.; Kužel, S.

    2013-01-01

    Roč. 26, č. 4 (2013), s. 199-203 ISSN 2151-321X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : grass pollen pollution * biofuels farming * temperate climate * PK-fertilization * N-fertilization * phenolic Subject RIV: EH - Ecology, Behaviour Impact factor: 0.556, year: 2013

  16. Global grass (Poaceae) success underpinned by traits facilitating colonization, persistence and habitat transformation.

    Science.gov (United States)

    Linder, H P; Lehmann, Caroline E R; Archibald, Sally; Osborne, Colin P; Richardson, David M

    2018-05-01

    Poaceae (the grasses) is arguably the most successful plant family, in terms of its global occurrence in (almost) all ecosystems with angiosperms, its ecological dominance in many ecosystems, and high species richness. We suggest that the success of grasses is best understood in context of their capacity to colonize, persist, and transform environments (the "Viking syndrome"). This results from combining effective long-distance dispersal, efficacious establishment biology, ecological flexibility, resilience to disturbance and the capacity to modify environments by changing the nature of fire and mammalian herbivory. We identify a diverse set of functional traits linked to dispersal, establishment and competitive abilities. Enhanced long-distance dispersal is determined by anemochory, epizoochory and endozoochory and is facilitated via the spikelet (and especially the awned lemma) which functions as the dispersal unit. Establishment success could be a consequence of the precocious embryo and large starch reserves, which may underpin the extremely short generation times in grasses. Post-establishment genetic bottlenecks may be mitigated by wind pollination and the widespread occurrence of polyploidy, in combination with gametic self-incompatibility. The ecological competitiveness of grasses is corroborated by their dominance across the range of environmental extremes tolerated by angiosperms, facilitated by both C 3 and C 4 photosynthesis, well-developed frost tolerance in several clades, and a sympodial growth form that enabled the evolution of both annual and long-lived life forms. Finally, absence of investment in wood (except in bamboos), and the presence of persistent buds at or below ground level, provides tolerance of repeated defoliation (whether by fire, frost, drought or herbivores). Biotic modification of environments via feedbacks with herbivory or fire reinforce grass dominance leading to open ecosystems. Grasses can be both palatable and productive

  17. Germination of Themeda triandra (Kangaroo grass) as affected by ...

    African Journals Online (AJOL)

    Low rainfall in range areas restricts germination, growth and development of majority of range grasses. However, germination and establishment potential of forage grasses vary and depends on environmental conditions. Themeda triandra is an excellent known grass to grow under different environmental conditions.

  18. Convex relationships in ecosystems containing mixtures of trees and grass

    CSIR Research Space (South Africa)

    Scholes, RJ

    2003-12-01

    Full Text Available The relationship between grass production and the quantity of trees in mixed tree-grass ecosystems (savannas) is convex for all or most of its range. In other words, the grass production declines more steeply per unit increase in tree quantity...

  19. Effects of an invasive grass on the demography of the Caribbean cactus Harrisia portoricensis: Implications for cacti conservation

    Science.gov (United States)

    Rojas-Sandoval, Julissa; Meléndez-Ackerman, Elvia

    2012-05-01

    The impact of exotic species around the world is among the primary threats to the conservation and management of rare and endangered species. In this work we asked whether or not the presence of the African grass Megathyrsus maximus on Mona Island was associated with negative impacts on the demography of the endangered Caribbean cactus Harrisia portoricensis. To address this question we performed field observations where we compared demographic data collected at un-manipulated areas invaded by Megathyrsus with un-manipulated areas non-invaded by this exotic grass. Additionally, demographic data were also collected in areas in which we removed the exotic grass biomass using two alternative treatments: complete and partial grass removal. Results demonstrated that the presence of Megathyrsus has negative effects on demographic parameters of Harrisia at various stages throughout its life cycle. In general, the survival, growth, and reproduction of Harrisia plants were depressed under the presence of Megathyrsus. Growth and survival of seedlings and juveniles of Harrisia were more impacted by the presence of Megathyrsus than adult performance and seedling recruitment only occurred in areas with grass absence. Our combined results suggest that modifications of the micro-environment by the presence of Megathyrsus may add an additional level of vulnerability to the persistence of Harrisia, and as such this factor must be considered when designing conservation strategies for this endangered species. This study highlights the need for a greater emphasis on understanding the interactions between invasive grass species and native cacti, and the importance of such information in designing conservation strategies for cacti species elsewhere.

  20. 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.

  1. Multiculturalism, Mauritian Style : Cultural Diversity, Belonging, and a Secular State

    NARCIS (Netherlands)

    Ng Tseung-Wong, Caroline; Verkuijten, Maykel

    2015-01-01

    Multiculturalism is on the retreat in many Western countries. As an ideology, it is criticized for failing to engender national belonging and social cohesion and thereby to encourage groups of citizens to have parallel lives. In this article, we present the case of Mauritius that is often viewed as

  2. Experiences of School Belonging for Young Children with Refugee Backgrounds

    Science.gov (United States)

    Due, Clemence; Riggs, Damien W.; Augoustinos, Martha

    2016-01-01

    Previous research with adolescents with refugee backgrounds living in countries of resettlement has found that school belonging has an impact on a range of well-being and developmental outcomes, including mental health, peer relationships, self-esteem and self-efficacy, and academic achievement. However, very little research has explored school…

  3. Relentless Verity: Education for Being-Becoming-Belonging.

    Science.gov (United States)

    Kidd, James Robbins

    The dynamic relationship of the concepts of being, becoming, and belonging is and must be the heart and central goal of adult education. The concept can be understood most readily by examination of the writings of humanist psychologists such as Carl Rogers, Fritz Perls, Gordon Allport, and Abraham Maslow. Some characteristics or dimensions of an…

  4. Discrimination and Sleep: The Protective Role of School Belonging

    Science.gov (United States)

    Huynh, Virginia W.; Gillen-O'Neel, Cari

    2016-01-01

    Ethnic minority adolescents experience certain sleep problems, yet factors that affect their sleep are poorly understood. This study examined the association between ethnic discrimination and sleep during adolescence and the extent to which perceived stress mediated these associations. This study also examined whether school belonging can protect…

  5. Major Decisions: Motivations for Selecting a Major, Satisfaction, and Belonging

    Science.gov (United States)

    Soria, Krista M.; Stebleton, Michael

    2013-01-01

    In this paper, we analyzed the relationship between students' motivations for choosing academic majors and their satisfaction and sense of belonging on campus. Based on a multi-institutional survey of students who attended large, public, research universities in 2009, the results suggest that external extrinsic motivations for selecting a major…

  6. Examining belonging at the interface of ethnicity, social status and ...

    African Journals Online (AJOL)

    Examining belonging at the interface of ethnicity, social status and masculinities in transnational space among foreign African male students at the University of ... finance and production as well as the on going processes of political and economic integration has led to an unprecedented increase in international migration.

  7. The politics of identity, belonging and the integration of African ...

    African Journals Online (AJOL)

    This article will be looking at the political and institutional structures in place, which either facilitate or constrain a sense of belonging and integration of professional migrants of African origin into the new democratic state of South Africa. Discussions in this article are based on a qualitative in-depth study conducted among ...

  8. DNA Methylation of T1R1 Gene in the Vegetarian Adaptation of Grass Carp Ctenopharyngodon idella.

    Science.gov (United States)

    Cai, Wenjing; He, Shan; Liang, Xu-Fang; Yuan, Xiaochen

    2018-05-02

    Although previous studies have indicated importance of taste receptors in food habits formation in mammals, little is known about those in fish. Grass carp is an excellent model for studying vegetarian adaptation, as it shows food habit transition from carnivore to herbivore. In the present study, pseudogenization or frameshift mutations of the umami receptors that hypothesized related to dietary switch in vertebrates, were not found in grass carp, suggesting other mechanisms for vegetarian adaptation in grass carp. T1R1 and T1R3 strongly responded to L-Arg and L-Lys, differing from those of zebrafish and medaka, contributing to high species specificity in amino acid preferences and diet selection of grass carp. After food habit transition of grass carp, DNA methylation levels were higher in CPG1 and CPG3 islands of upstream control region of T1R1 gene. Luciferase activity assay of upstream regulatory region of T1R1 (-2500-0 bp) without CPG1 or CPG3 indicated that CPG1 and CPG3 might be involved in transcriptional regulation of T1R1 gene. Subsequently, high DNA methylation decreased expression of T1R1 in intestinal tract. It could be a new mechanism to explain, at least partially, the vegetarian adaptation of grass carp by regulation of expression of umami receptor via epigenetic modification.

  9. Belongings: Oral History, Objects and an Online Exhibition

    Directory of Open Access Journals (Sweden)

    Janis Wilton

    2009-11-01

    Full Text Available The New South Wales Migration Heritage Centre was established in 1998. Since 2003 its physical presence has been located within Sydney’s Powerhouse Museum and it has had the strategic brief to record the memories of ageing migrants before their stories are lost. The Centre is, however, a museum without a collection; a heritage authority without heritage sites; a cultural institution whose main presence is in cyberspace. Among its high profile projects is one entitled Objects through time and another Belongings. Both focus on the ways in which objects can convey aspects of the migration experience. Belongings, the focus of this article, presents the remembered experiences of people who migrated to Australia after World War II, and seeks to highlight significant features of their experiences through asking them to share their memories and to nominate and talk about significant objects. As a project it grew out of movable heritage policy work within state government agencies, and its initiators – John Petersen, Kylie Winkworth and Meredith Walker – were central players in this development. It was also inspired by the National Quilt Register of the Pioneer Women’s Hut at Tumbarumba. With its object-centred approach and accompanying edited interview transcripts, Belongings provides a focus for exploring the messages and emphases that emerge when oral history interviews concerned with migration have the specific brief to ask about material culture and its significance. Belongings also enables an exploration of the layering of those messages that emerges when object captions are located back in the context of the oral history interviews from which they were extracted. As a virtual exhibition, Belongings also provides the opportunity to consider the challenges for museums (virtual and real when they need to condense the richness of migrant oral histories and life stories to captioned objects that can be put on display.

  10. Cross-species amplification of 105 Lolium perenne SSR loci in 23 species within the Poaceae

    DEFF Research Database (Denmark)

    Jensen, Louise Bach; Holm, Preben Bach; Lübberstedt, Thomas

    2007-01-01

    Amplification of 105 Lolium perenne SSR markers was studied in 23 grass species representing seven tribes from three subfamilies of Poaceae. Twelve of the SSR markers are published for the first time. Between 2% and 96% of the SSR markers could be amplified within a given species. A subset of eight...... SSR markers was evaluated for polymorphism across nine of the 23 grass species. Four to seven of the markers were polymorphic within each species, with an average detection of 2.4 alleles per species....

  11. Functional immunoglobulin E cross-reactivity between Pas n 1 of Bahia grass pollen and other group 1 grass pollen allergens.

    Science.gov (United States)

    Davies, J M; Dang, T D; Voskamp, A; Drew, A C; Biondo, M; Phung, M; Upham, J W; Rolland, J M; O'Hehir, R E

    2011-02-01

    Grass pollens are major triggers of allergic rhinitis and asthma, but the immunological relationships between pollen allergens of the subtropical Bahia grass, Paspalum notatum, and temperate grasses are unresolved. To assess serum IgE cross-reactivity between subtropical P. notatum and temperate Lolium perenne (Ryegrass) pollen allergens. Serum IgE reactivities of grass pollen-allergic patients with P. notatum, L. perenne and Cynodon dactylon (Bermuda grass) pollen extracts and their respective purified group 1 allergens, Pas n 1, Lol p 1 and Cyn d 1, were compared by immunoblotting, ELISA and basophil activation. In a cohort of 51 patients from a temperate region, a high frequency of IgE reactivity with each grass pollen was detected, but reactivity with L. perenne pollen was substantially greater than with P. notatum and C. dactylon pollen. Similarly, serum IgE reactivity with Lol p 1 was greater than with Pas n 1 or Cyn d 1. For seven of eight sera studied in detail, asymmetric serum IgE cross-reactivity was observed; L. perenne pollen inhibited IgE reactivity with P. notatum pollen but not the converse, and IgE reactivity with Pas n 1 was inhibited by Lol p 1 but IgE reactivity with Lol p 1 was not inhibited by Pas n 1 or Cyn d 1. Importantly, P. notatum pollen and Pas n 1 activated basophils in grass pollen-allergic patients from a temperate region, although stimulation was greater by pollen of L. perenne than P. notatum or C. dactylon, and by Lol p 1 than Pas n 1 or Cyn d 1. In contrast, a cohort of 47 patients from a subtropical region showed similar IgE reactivity with P. notatum and L. perenne pollen, and reciprocal cross-inhibition of IgE reactivity between L. perenne and P. notatum. Pollen allergens of the subtropical P. notatum, including Pas n 1, show clinically relevant IgE cross-reactivity with pollen allergens of L. perenne but also species-specific IgE reactivity. © 2011 Blackwell Publishing Ltd.

  12. Ectoparasites of dogs belonging to people in resource-poor communities in North West Province, South Africa

    Directory of Open Access Journals (Sweden)

    N.R. Bryson

    2000-07-01

    Full Text Available A total of 344 dogs belonging to people in resource-poor communities in North West Province, South Africa, was examined for ectoparasites, and all visible arthropods were collected from the left side of each dog. By doubling these numbers it was estimated that the dogs harboured 14 724 ixodid ticks, belonging to 6 species, 1028 fleas, belonging to 2 species, and 26 lice. Haemaphysalis leachi accounted for 420 and Rhipicephalus sanguineus for 14 226 of the ticks. Pure infestations of H. leachi were present on 14 dogs and of R. sanguineus on 172 dogs. Small numbers of Amblyomma hebraeum, R. appendiculatus, R. evertsi evertsi and R. simus were also collected. The predominance of R. sanguineus accounts for the high prevalence of canine ehrlichiosis (Ehrlichia canis within the survey region, compared to canine babesiosis (Babesia canis, which is transmitted by H. leachi, and is a much rarer disease.

  13. 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.

  14. Warm season grass establishment (in one year without the weeds)

    International Nuclear Information System (INIS)

    Downing, D.

    1998-01-01

    Native warm season grasses, big bluestem and indian, were established by the broadcast method on a relatively large area (130 acres) of reclaimed coal surface-mined land in Perry County, Illinois. Existing vegetation was controlled using two quarts of Round-Up and 12 ounces of Plateau per acre the first week of May. Five pounds of pure live seed of both species were applied by airflow using 100 pounds per acre of 0-46-0 and 100 pounds per acre of 0-0-60, primarily to carry the seed. The surface was cultipacked to insure good seed to soil contact. Planting was initiated and completed the last week of June. An estimated 95% to 100% ground cover was evident by mid to late August. By mid September, numerous big blue stem flower/seed stalks were noticeable

  15. Factors influencing the grass carp gut microbiome and its effect on metabolism.

    Science.gov (United States)

    Ni, Jiajia; Yan, Qingyun; Yu, Yuhe; Zhang, Tanglin

    2014-03-01

    Gut microbiota have attracted extensive attention recently because of their important role in host metabolism, immunity and health maintenance. The present study focused on factors affecting the gut microbiome of grass carp (Ctenopharyngodon idella) and further explored the potential effect of the gut microbiome on metabolism. Totally, 43.39 Gb of screened metagenomic sequences obtained from 24 gut samples were fully analysed. We detected 1228 phylotypes (116 Archaea and 1112 Bacteria), most of which belonged to the phyla Firmicutes, Proteobacteria and Fusobacteria. Totally, 41335 of the detected open reading frames (ORFs) were matched to Kyoto Encyclopedia of Genes and Genomes pathways, and carbohydrate and amino acid metabolism was the main matched pathway deduced from the annotated ORFs. Redundancy analysis based on the phylogenetic composition and gene composition of the gut microbiome indicated that gut fullness and feeding (i.e. ryegrass vs. commercial feed, and pond-cultured vs. wild) were significantly related to the gut microbiome. Moreover, many biosynthesis and metabolism pathways of carbohydrates, amino acids and lipids were significantly enhanced by the gut microbiome in ryegrass-fed grass carp. These findings suggest that the metabolic role played by the gut microbiome in grass carp can be affected by feeding. These findings contribute to the field of fish gut microbial ecology and also provide a basis for follow-up functional studies. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  16. Initial Investigation on the Diet of Eastern Grass Owl (Tyto longimembris in Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Loung Lin

    2007-03-01

    Full Text Available This investigation, undertaken in the two regions of Nanshi and Yujing in Tainan County over the period of 2001 to 2003, included three nests belonging to the Eastern Grass Owl (Tyto longimembris. From these, we collected a total of 157 owl pellets. Analysis and examination of the pellets revealed 329 prey items. More in-depth investigation determined that 95.1% of the Eastern Grass Owl pellets collected consisted of mammal remains, while the remaining 4.9% were made up of bird remains. Of the various types of mammals consumed, rats made up the highest proportion, with a total of 285 rats, accounting for 86.6%. This was followed by 27 shrews and moles, accounting for 8.2%. Hares and birds were seldom caught and consumed. The findings suggested that rats are the main food source of the Eastern Grass Owl, with the Spinus Country-rat (Rattus losea comprising the majority with 136 counted (41.3%, followed by the Formosan Mouse (Mus caroli with 96 counted (29.2%. Regarding biomass, the reversion method was used to calculate that owls at the three nests consumed approximately 22,987 grams of mammal and 480 grams of bird, accounting for 98.0% and 2.0%, respectively. The biomass consumed for each pellet was approximately 149.5 g.

  17. 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)

    Thorhaug, Anitra; Berlyn, Graeme P.; Poulos, Helen M.; Goodale, Uromi M.

    2015-01-01

    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

  18. The diversity of polyprenol pattern in leaves of fruit trees belonging to Rosaceae and Cornaceae.

    Science.gov (United States)

    Wanke, M; Chojnacki, T; Swiezewska, E

    1998-01-01

    The polyprenol pattern in leaves of fruit trees belonging to the Rosaceae (genera: Prunus, Malus) and Cornaceae (genus: Cornus) families is presented. The content of polyprenyl acetates varied within plant species between 10-50 mg per gram of dry weight. In genus Prunus, Cornus and in representatives of species Malus domestica, a mixture of polyprenols composed of 18, 19, 20, 21 isoprene units was found. In six species of genus Prunus (sour-cherry): P. serrulata-spontanea, P. yedoensis, P. fruticosa. P. kurilensis, P. subhirtella and P. incisa the presence of a second polyprenol family, i.e. the group of prenologues consisting of prenol -35, -36, -37, etc. up to -42 was detected.

  19. 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) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  20. Reducing tillage intensity affects the cumulative emergence dynamics of annual grass weeds in winter cereals

    DEFF Research Database (Denmark)

    Scherner, A; Melander, B; Jensen, P K

    2017-01-01

    Annual grass weeds such as Apera spica-venti and Vulpia myuros are promoted in non-inversion tillage systems and winter cereal-based crop rotations. Unsatisfactory weed control in these conditions is often associated with a poor understanding of the emergence pattern of these weed species. The aim...... with a higher total emergence seen under direct drilling, followed by pre-sowing tine cultivation and ploughing. The emergence patterns of all species were differently influenced by the tillage systems, suggesting that under direct drilling, in which these species occur simultaneously, management interventions...

  1. Natural lactic acid bacteria population of tropical grasses and their fermentation factor analysis of silage prepared with cellulase and inoculant.

    Science.gov (United States)

    Khota, Waroon; Pholsen, Suradej; Higgs, David; Cai, Yimin

    2016-12-01

    Natural lactic acid bacteria (LAB) populations in tropical grasses and their fermentation characteristics on silage prepared with cellulase enzyme and LAB inoculants were studied. A commercial inoculant Lactobacillus plantarum Chikuso 1 (CH), a local selected strain Lactobacillus casei TH14 (TH14), and 2 cellulases, Acremonium cellulase (AC) and Maicelase (MC; Meiji Seika Pharma Co. Ltd., Tokyo, Japan), were used as additives to silage preparation with fresh and wilted (6 h) Guinea grass and Napier grass. Silage was prepared using a laboratory-scale fermentation system. Treatments were CH, TH14, AC at 0.01% fresh matter, AC 0.1%, MC 0.01%, MC 0.1%, CH+AC 0.01%, CH+AC 0.1%, CH+MC 0.01%, CH+MC 0.1%, TH14+AC 0.1%, TH14+AC 0.01%, TH14+MC 0.1%, and TH14+MC 0.01%. Microorganism counts of Guinea grass and Napier grass before ensiling were 10 2 LAB and 10 6 aerobic bacteria; these increased during wilting. Based on morphological and biochemical characteristics, and 16S rRNA gene sequence analysis, natural strains from both grasses were identified as L. plantarum, L. casei, Lactobacillus acidipiscis, Leuconostoc pseudomesenteroides, Leuconostoc garlicum, Weissella confusa, and Lactococcus lactis. Lactobacillus plantarum and L. casei are the dominant species and could grow at lower pH and produce more lactic acid than the other isolates. Crude protein and neutral detergent fiber were 5.8 and 83.7% of dry matter (DM) for Guinea grass, and 7.5 and 77.1% of DM for Napier grass. Guinea grass had a low level of water-soluble carbohydrates (0.39% of DM). Guinea grass silage treated with cellulase had a lower pH and higher lactic acid content than control and LAB treatments. The 0.1% AC and MC treatments had the best result for fermentation quality. All high water-soluble carbohydrate (2.38% DM) Napier grass silages showed good fermentation quality. Compared with control and LAB-inoculated silage, the cellulase-treated silages had significantly higher crude protein content and

  2. 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

    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...

  3. Expression, purification, crystallization and preliminary X-ray diffraction analysis of grass carp β2-microglobulin

    International Nuclear Information System (INIS)

    Chen, Weihong; Chu, Fuliang; Peng, Hao; Zhang, Jianhua; Qi, Jianxun; Jiang, Fan; Xia, Chun; Gao, Feng

    2008-01-01

    Grass carp β 2 -microglobulin was expressed in E. coli, purified to homogeneity and crystallized using the hanging-drop vapour-diffusion method with PEG 2K as precipitant. The crystals obtained belong to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 38.72, b = 40.65, c = 71.12 Å. β 2 -Microglobulin (β 2 m) is an essential subunit of MHC I molecules; it stabilizes the structure of MHC I and plays a pivotal role in coreceptor recognition. To date, structures of β 2 m have been solved for three different mammals: human, mouse and cattle. In order to illuminate the molecular evolutionary origin of β2m, an understanding of its structure in lower vertebrates becomes important. Here, grass carp (Ctenopharyngodon idellus) β 2 m (Ctid-β 2 m) was expressed, purified and crystallized. Diffraction data were collected to a resolution of 2.5 Å. The crystal belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 38.72, b = 40.65, c = 71.12 Å. The Matthews coefficient and the solvent content were calculated to be 2.56 Å Da −1 and 52.07%, respectively, for one molecule per asymmetric unit. The structure has been solved by molecular replacement using monomeric human β 2 m as a model

  4. Cosmopolitanism, geographical imaginaries and belonging in North London.

    Science.gov (United States)

    Devadason, Ranji

    2010-01-01

    Cosmopolitanism has been described as the cultural habitus of globalisation. It is therefore, albeit defined somewhat loosely, often associated with ethnically diverse, global cities. This paper considers the extent to which London engenders cosmopolitan values amongst its residents. It draws on survey data from the LOCAL MULTIDEM study of minorities' political participation to address these themes. The analysis examines perceptions of respect, belonging and geographical imaginaries - amongst established minorities and the ethnic majority - in north London. It is argued that cosmopolitan ethics are transformative and dialectical and, critically, cannot remain the preserve of the privileged in multi-ethnic neighbourhoods. The analysis presented demonstrates that a sense of belonging and cosmopolitan imaginaries are not evenly accessed by different ethnic groups; notably, that Bangladeshi Londoners who are born and bred in the city are less likely to appropriate these discourses than Caribbean, Indian or White residents.

  5. Creating a hybrid sense of belonging in Copenhagen

    DEFF Research Database (Denmark)

    Monka, Malene

    to local products and culturally by enacting the competition (Coupland 2014). Yet, I argue that the participants do not create a copy of the activity as it is played out in its original setting, rather it is ascribed a certain urban coolness, which might be a way of demonstrating hybrid senses of belonging...... the first event, a Facebook-community was set up to organize and promote succeeding events. By analyzing empirical data from Facebook I point to how the participants draw on a range of ‘languagecultural practices’ (Cornips & de Rooij in press) to re-contextualize the rural tradition to an urban setting. I...... discuss whether and how the two dimensions of ‘belonging’ (Antonsich 2010), i.e. place-belongingness and politics of belonging, are made relevant by the participants. The connection to Southern Jutland is pointed to in several ways: linguistically by using dialect orthography, materially by pointing...

  6. KINSHIP ANALYSIS OF GRASS JELLY IN REGENCY OF GIANYAR, TABANAN AND BADUNG BASED ON MORPHOLOGICAL AND ANATOMICAL CHARACTERISTIC

    Directory of Open Access Journals (Sweden)

    Eka Budi Mursa fitri

    2016-12-01

    Full Text Available Grass jelly is one of the plants that has considerable potential as medicine and drinks. This study was conducted to determine how kinship plant species Grass jelly from three districts. The Exploration of Grass jelly plants conducted in Gianyar, Tabanan and Badung, Bali province. Making preparations in the Structures Laboratory of Plant Development (SPT Faculty Udayana University and the Center of Veterinary (BBVet. This research was carried out from September 2015-January 2016. This research method using the technique of embedding and fresh slices, FAA fixative (formaldehyde: glacial acetic acid: alcohol 70% = 1: 1: 9, 1% safranin staining in 70% alcohol. For the analysis of kinship qualitative and quantitative data were suspended leaf anatomical characters to create table Taxonomy Operation Unit (OTU. The results are used OTU table into mini-tab program version 14.The result showed that four species of grass jelly plants are Cyclea barbata, Stephania japonica, Stephania capitata and Cocculus orbiculatus. Leaf form is like shields and ellipse. Kinship four types of plant grass jelly from three districts are very much based on morphological and anatomical characters (level 15.64% similarity.

  7. When the mosque goes Beethoven: Expressing religious belongings through music

    Directory of Open Access Journals (Sweden)

    Monika Salzbrunn

    2016-06-01

    Full Text Available The present article will provide insight on music as a vector of religious belonging: a female choir at a mosque in the Lake Geneva Metropolitan Region has reinterpreted Beethoven’s Ode to Joy with new text about the glory of the Messenger, and a regional political and religious event which has united music from Syria, Kosovo and Tunisia in order to put on stage the cosmopolitan characteristics of Swiss Muslims. Religious and national belonging as well as cultural references can be expressed in different ways through ritual practices (prayer, celebrations, food or clothing. These practices, influenced by gender and age, are highly diverse. Celebrations that are performed in public also depend on the local and global political context, the specific social situation and the specific place (location, public, legal framework etc.. As part of a broader research project on “(Invisible Islam in the city,” a research team directed by Monika Salzbrunn has observed various forms of celebration – both religious and secular festive events – in which Muslim citizens are involved. At what audience are these musical performances directed? Can we really separate an analysis of religious belongings from an analysis of political and/or cultural performances?

  8. The use of less common grass varieties as a factor of increasing forage lands productivity

    Directory of Open Access Journals (Sweden)

    В. Д. Бугайов

    2017-03-01

    Full Text Available Purpose. To assess introduced samples of drought-resistant species of perennial grasses, select a promising parent material and create on its base high-yielding varie­ ies with economic characters. Methods. Field experiment, laboratory testing. Results. The results of studies on introduction and breeding were given aimed to improve drought tolerance of non-traditional perennial grasses under the conditions of the Right-Bank Forest-Steppe zone of Ukraine. Based on the selected parent material, varieties were created by the use of hybridization and ecotype breeding methods and then entered into the State Register of plant varieties suitable for dissemination in Ukraine, among them: intermediate wheatgrass (Elytrigia intermedia (Host Nevski – ‘Hors’, crested wheatgrass (Agropyron cristatum (L. Gaertn. – ‘Petrivskyi’; meadow brome (Bromus riparia Rehm. – ‘Boian’; slender wheatgrass (Roegneria trachycaulon (Link Nevski – ‘Co­umb’. As compared with conventional, relatively drought-tolerant species of smooth brome (Bromopsis inermis (Leyss. Holub – ‘Mars’, increment of dry matter content of these species in the extreme drought conditions of 2011 was increased by 1,52–3,73 t/ha. Under more sufficient moistening conditions of 2012, slender wheatgrass ‘Columb’ was at the level of the сheck variety in terms of this indicator. Other varieties exceeded it by 1.44–3.22 t/ha. The data was given including seed productivity and sowing quality indicators, after-ripening duration and economic fitness of seeds. Conclusions. The use of the recommended varieties of drought-resistant species of perennial grasses as part of grass mixtures will increase significantly the productivity of grasslands and pastures in the current context of climate change.

  9. Phyto-therapeutic claims about euphorbeaceous plants belonging to pakistan; an ethnomedicinal review

    International Nuclear Information System (INIS)

    Khalil, A.T.; Shinwari, ZK.

    2014-01-01

    Ethnobotany has attracted many researchers in the modern era in order to find novel and cheaper approaches to alleviate the human sufferings. Since ancient times, plants are used traditionally for cure. In the last few years herbal practices have attained global relevance. Among the different important plant families, the spurge family (Euphorbiaceae) is well known for its therapeutic potential. Different plants are used in folk medicinal practices in different forms to treat several diseases. Plants belonging to Euphorbiaceae are common in Pakistan and used for different purposes. The present communication deals with the different ethnomedicinal uses reported in the peer reviewed articles of the various species present in Pakistan. (author)

  10. Lead-210 and polonium-210 in grass

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C R

    1960-07-16

    It appears that an important contribution to the observed ..cap alpha..-activity of grass may be provided by a process of natural fall-out in which lead-210 resulting from decay of atmospheric radon, together with a fraction of the equilibrium amount of its descendant polonium-210 are deposited by rainfall directly on to foliage. Metabolic uptake of part of this activity by sheep is indicated by the presence in the kidney of polonium-210. 6 references, 1 figure, 2 tables.

  11. Phylogenetic analysis of the expansion of the MATH-BTB gene family in the grasses.

    Science.gov (United States)

    Juranić, Martina; Dresselhaus, Thomas

    2014-01-01

    MATH-BTB proteins are known to act as substrate-specific adaptors of cullin3 (CUL3)-based ubiquitin E3 ligases to target protein for ubiquitination. In a previous study we reported the presence of 31 MATH-BTB genes in the maize genome and determined the regulatory role of the MATH-BTB protein MAB1 during meiosis to mitosis transition. In contrast to maize, there are only 6 homologous genes in the model plant Arabidopsis, while this family has largely expanded in grasses. Here, we report a phylogenetic analysis of the MATH-BTB gene family in 9 land plant species including various mosses, eudicots, and grasses. We extend a previous classification of the plant MATH-BTB family and additionally arrange the expanded group into 5 grass-specific clades. Synteny studies indicate that expansion occurred to a large extent due to local gene duplications. Expression studies of 3 closely related MATH-BTB genes in maize (MAB1-3) indicate highly specific expression pattern. In summary, this work provides a solid base for further studies comparing genetic and functional information of the MATH-BTB family especially in the grasses.

  12. Effects of processing phases on the quality of massai grass seeds

    Directory of Open Access Journals (Sweden)

    Lilian Faria de Melo

    Full Text Available ABSTRACT Massai grass is an important tropical forage grass. The harvested seeds upon being received by the company, are found to be contaminated with impurities which are removable by processing machines. This procedure is necessary to produce seeds of a quality level within standards established for commercialization and sowing purposes. The objective of this project was to evaluate the effects of processing phases on the physical and physiological quality of massai grass (Panicum maximum x P. infestum, cv. Massai seeds for commercialization purposes. Seeds were sampled before processing and after leaving the air and screen machine (upper and intermediary screens and bottom; first gravity table (drift, upper and intermediate spouts; treating machine; and second gravity table (upper, intermediate, and lower spouts. Seeds were evaluated as to water content, physical (purity and 1,000 seeds weight and physiological quality (germination, first count of germination, seedling vigor classification, accelerated aging, seedling emergence in the field, speed of emergence index, and primary root length, shoot length. Massai grass seeds had their physical and physiological qualities improved when they were processed by an air and screen machine and a gravity table. Seeds from the intermediate discharge spout of the first gravity table, after going through the air and screen machine, are those of with highest physiological potential. The seeds of this species do not need to be processed to fit the germination and purity standards when the national market is the goal.

  13. Molecular features of grass allergens and development of biotechnological approaches for allergy prevention.

    Science.gov (United States)

    Devis, Deborah L; Davies, Janet M; Zhang, Dabing

    2017-09-01

    Allergic diseases are characterized by elevated allergen-specific IgE and excessive inflammatory cell responses. Among the reported plant allergens, grass pollen and grain allergens, derived from agriculturally important members of the Poaceae family such as rice, wheat and barley, are the most dominant and difficult to prevent. Although many allergen homologs have been predicted from species such as wheat and timothy grass, fundamental aspects such as the evolution and function of plant pollen allergens remain largely unclear. With the development of genetic engineering and genomics, more primary sequences, functions and structures of plant allergens have been uncovered, and molecular component-based allergen-specific immunotherapies are being developed. In this review, we aim to provide an update on (i) the distribution and importance of pollen and grain allergens of the Poaceae family, (ii) the origin and evolution, and functional aspects of plant pollen allergens, (iii) developments of allergen-specific immunotherapy for pollen allergy using biotechnology and (iv) development of less allergenic plants using gene engineering techniques. We also discuss future trends in revealing fundamental aspects of grass pollen allergens and possible biotechnological approaches to reduce the amount of pollen allergens in grasses. Copyright © 2017. Published by Elsevier Inc.

  14. Role of grass-legume communities in revegetation of a subalpine mine site in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, K

    1982-01-01

    This study describes an investigation of the potential for pioneer grass-legume communities to stabilize and ameliorate geologically-fresh soil leading to the establishment of a self-sustaining, progressive plant succession on a surface-mined subalpine site. The study area is located 2000 m above sea level in the Canadian Rocky Mountains. Field studies revealed chronological trends in grass-legume communities at four sites revegetated during 1974-1978 including: species composition, legumes (Trifolium repens L., T. hybridum L. and Medicago sativa L.) performing increasingly poorly on the older sites; biomass changes, a shoot to root ratio (S/R) decreasing from 2.3 to 0.2 as the communities aged; and litter accumulation which continued even on the oldest site. Fertilizer (13-16-10) operationally applied at 150-391 kg/ha enhanced the growth of Dactylis gomerata L. and litter degradation, and acidified the soil. Nitrogen fertilization was also associated with two clear inverse relationships identified between D. glomerata and Festuca rubra L. biomass, and between soil pH and phosphorus levels. In greenhouse tests grasses were revealed to be more efficient soil nitrogen consumers than were legumes and nitrogen fixation decreased significantly (P < 0.01) and linearly with increasing grass seeding rates.

  15. Production cost of biomasses from eucalyptus and elefant grass for energy

    Directory of Open Access Journals (Sweden)

    Laurent Marie Roger Quéno

    2011-09-01

    Full Text Available This work established the unit energy cost generated from biomass of eucalyptus (Eucalyptus sp. and elephant grass (Pennisetum sp. and applied a sensitivity analysis to verify the influences of factors such as the silviculture of eucalyptus, production volume of each species, the cost of land and the interest rate. It was shown that the treatment of eucalyptus in very short rotation of 2 years with reform of stand every 6 years has a average cost of production higher than the traditional treatment of short rotation of 6 years with reform only at the age of 18. It was also observed that eucalyptus has a Production Cost on average of R$ 4,41 /Gj, lower than the elephant grass which is on average of R$ 5,44/Gj, which however has a higher annual capacity of dry matter production. The elephant grass has the possibility to compete with eucalyptus when a set of conditions is met: discount rate higher than or equal to 8%, High price of land, and elephant grass high volume production, greater than or equal to 35 tonnes of dry matter per hectare and year.

  16. Utilization of grasses for potential biofuel production and phytoremediation of heavy metal contaminated soils.

    Science.gov (United States)

    Balsamo, Ronald A; Kelly, William J; Satrio, Justinus A; Ruiz-Felix, M Nydia; Fetterman, Marisa; Wynn, Rodd; Hagel, Kristen

    2015-01-01

    This research focuses on investigating the use of common biofuel grasses to assess their potential as agents of long-term remediation of contaminated soils using lead as a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy grass may be potentially useful for long-term phytoremediation of heavy metal contaminated soils and describe novel techniques to track and remove contaminants from inception to useful product. Enzymatic digestion and thermochemical approaches are being used to convert this lignocellulosic feedstock into useful product (sugars, ethanol, biocrude oil+biochar). Preliminary studies on enzymatic hydrolysis and fast pyrolysis of the Switchgrass materials that were grown in heavy metal contaminated soil and non-contaminated soils show that the presence of lead in the Switchgrass material feedstock does not adversely affect the outcomes of the conversion processes. These results indicate that the modest levels of contaminant uptake allow these grass species to serve as phytoremediation agents as well as feedstocks for biofuel production in areas degraded by industrial pollution.

  17. The relative importance of different grass components in controlling runoff and erosion on a hillslope under simulated rainfall

    Science.gov (United States)

    Li, Changjia; Pan, Chengzhong

    2018-03-01

    The effects of vegetation cover on overland flow and erosion processes on hillslopes vary with vegetation type and spatial distribution and the different vegetation components, including the above- and below-ground biomass. However, few attempts have been made to quantify how these factors affect erosion processes. Field experimental plots (5 m × 2 m) with a slope of approximately 25° were constructed and simulated rainfall (60 mm hr-1) (Rainfall) and simulated rainfall combined with upslope overland flow (20 L min-1) (Rainfall + Flow) were applied. Three grass species were planted, specifically Astragalus adsurgens (A. adsurgens), Medicago sativa (M. sativa) and Cosmos bipinnatus (C. bipinnatus). To isolate and quantify the relative contributions of the above-ground grass parts (stems, litter cover and leaves) and the roots to reducing surface runoff and erosion, each of the three grass species was subjected to three treatments: intact grass control (IG), no litter or leaves (only the grass stems and roots were reserved) (NLL), and only roots remaining (OR). The results showed that planting grass significantly reduced overland flow rate and velocity and sediment yield, and the mean reductions were 21.8%, 29.1% and 67.1%, respectively. M. sativa performed the best in controlling water and soil losses due to its thick canopy and dense, fine roots. Grasses reduced soil erosion mainly during the early stage of overland flow generation. The above-ground grass parts primarily contributed to reducing overland flow rate and velocity, with mean relative contributions of 64% and 86%, respectively. The roots played a predominant role in reducing soil erosion, with mean contribution of 84%. Due to the impact of upslope inflow, overland flow rate and velocity and sediment yield increased under the Rainfall + Flow conditions. The results suggest that grass species on downslope parts of semi-arid hillslopes performed better in reducing water and soil losses. This study is

  18. 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.

  19. Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

    Directory of Open Access Journals (Sweden)

    Richard G. Silcock

    2015-01-01

    Full Text Available Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production.  Accessions sown at a site were determined by prior experience with them on a range of soils.  High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp.  Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana.  The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species.  While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises.  Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities.Keywords: Herbicide tolerance, persistence, forage yield, establishment ease, commercialization, seed production.DOI: 10.17138/TGFT(315-26

  20. Flora and fauna associated with prairie dog colonies and adjacent ungrazed mixed-grass prairie in western South Dakota

    Science.gov (United States)

    William Agnew; Daniel W. Uresk; Richard M. Hansen

    1986-01-01

    Vegetation, small rodents, and birds were sampled during the growing seasons of 2 years on prairie dog (Cynomys ludovicianus) colonies and adjacent mixed-grass prairie in western South Dakota. Prairie dog grazing decreased mulch cover, maximum height of vegetation, plant species richness, and tended to decrease live plant canopy cover compared to...

  1. Evaluating poverty grass (Danthonia spicata L.) for use in tees, fairways, or rough areas in golf courses in the midwest

    Science.gov (United States)

    Nadia E. Navarrete-Tindall; Brad Fresenburg; J.W. Van Sambeek

    2007-01-01

    Poverty grass (Danthonia spicata L.), a native, cool-season perennial bunchgrass with wide distribution in the United States, is being evaluated for its suitability for use on golf courses. The goal is to identify practices to improve seed germination and successfully establish field plots as monocultures or with other native species to mimic natural...

  2. Strong genetic differentiation in the invasive annual grass Bromus tectorum across the Mojave-Great Basin ecological transition zone

    Science.gov (United States)

    Susan E. Meyer; Elizabeth A. Leger; Desiree R. Eldon; Craig E. Coleman

    2016-01-01

    Bromus tectorum, an inbreeding annual grass, is a dominant invader in sagebrush steppe habitat in North America. It is also common in warm and salt deserts, displaying a larger environmental tolerance than most native species. We tested the hypothesis that a suite of habitat-specific B. tectorum lineages dominates warm desert habitats. We sampled 30 B....

  3. Effect of an Invasive Grass on Ambient Rates of Decomposition and Microbial Community Structure: A Search for Causality

    Science.gov (United States)

    In sutu decomposition of above and below ground plant biomass of the native grass species Andropogon glmoeratus (Walt.) B.S.P and exotic Imperata cylindrica (L.) Beauv. (cogongrass) was investigated using litter bags over the course of a 12 month period. The above and below ground biomass of the inv...

  4. Ploidy determination of buffel grass accessions in the USDA National Plant Germplasm System collection by flow cytometry

    Science.gov (United States)

    Buffelgrass [Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.] is an important forage and range grass in many of the semi-arid tropical and subtropical regions of the world. The species reproduces primarily by apomixis but it is highly diverse because a wide array of different apomictic ecoty...

  5. Genome Sequence of Bivens Arm Virus, a Tibrovirus Belonging to the Species Tibrogargan virus (Mononegavirales: Rhabdoviridae).

    OpenAIRE

    Chiu, Charles; Lauck, M; Yú, SQ; Caì, Y; Hensley, LE; Chiu, CY; O'Connor, DH; Kuhn, JH

    2015-01-01

    The new rhabdoviral genus Tibrovirus currently has two members, Coastal Plains virus and Tibrogargan virus. Here, we report the coding-complete genome sequence of a putative member of this genus, Bivens Arm virus. A genomic comparison reveals Bivens Arm vi

  6. Genome Sequence of Bivens Arm Virus, a Tibrovirus Belonging to the Species Tibrogargan virus (Mononegavirales: Rhabdoviridae).

    Science.gov (United States)

    Lauck, Michael; Yú, Shu Qìng; Caì, Yíngyún; Hensley, Lisa E; Chiu, Charles Y; O'Connor, David H; Kuhn, Jens H

    2015-03-19

    The new rhabdoviral genus Tibrovirus currently has two members, Coastal Plains virus and Tibrogargan virus. Here, we report the coding-complete genome sequence of a putative member of this genus, Bivens Arm virus. A genomic comparison reveals Bivens Arm virus to be closely related to, but distinct from, Tibrogargan virus. Copyright © 2015 Lauck et al.

  7. Diversity in Production of Xylan-Degrading Enzymes Among Species Belonging to the Trichoderma Section Longibrachiatum

    NARCIS (Netherlands)

    Toth, K.; Gool, van M.P.; Schols, H.A.; Samuels, G.J.; Gruppen, H.; Szakacs, G.

    2013-01-01

    Xylan is an important part of plant biomass and represents a renewable raw material for biorefineries. Contrary to cellulose, the structure of hemicellulose is quite complex. Therefore, the biodegradation of xylan needs the cooperation of many enzymes. For industrial production of xylanase

  8. On a new Longicorn genus and species, belonging to the Agniidae

    NARCIS (Netherlands)

    Neervoort van de Poll, J.R.H.

    1886-01-01

    Caput mediocre, supra angustius; tuberibus antenniferis validis, breviusculis; oculorum lobi inferiores magni, subconvexi. — Frons trapeziformis, subconvexa; mandibulae robustae oblique prominentes. — Antennae ♂ longissimae, scapo, cylindrico, elongato, cicatricoso, articulo tertio longiore,

  9. Diversity in production of xyaln-degrading enzymes among species belonging to the Trichoderma section Longibrachiatum

    Science.gov (United States)

    Xylan is an important part of plant biomass and represents a renewable raw material for biorefineries. Contrary to cellulose, the structure of hemicellulose is quite complex. Therefore, the biodegradation of xylan needs the cooperation of many enzymes. For industrial production of xylanase multienzy...

  10. Spore germination of fungi belonging to Aspergillus species under deep-sea conditions

    Digital Repository Service at National Institute of Oceanography (India)

    Damare, S.R.; Nagarajan, M.; Raghukumar, C.

    Culture Collection (Chandigarh, India) were used. 2.2. Media Sediment extract (SE) was prepared using sediments collected from the Central Indian Basin. Sediment (30% (w/v)) was suspended in sterile seawater containing antibiotics (penicillin— 40,000U... extract was used as one of the growth media. Malt extract broth (MEB, HiMedia Laboratories, India) prepared in seawater was used for the comparative studies. 2.3. Fungal spore suspension The cultures were inoculated onto malt extract agar (MEA) plates...

  11. Ribosomal DNA variation in finger millet and wild species of Eleusine (Poaceae).

    Science.gov (United States)

    Hilu, K W; Johnson, J L

    1992-04-01

    Finger millet is an important cereal crop in the semi-arid regions of Africa and India. The crop belongs to the grass genus Eleusine, which includes nine annual and perennial species native to Africa except for the New World species E. tristachya. Ribosomal DNA (rDNA) variation in finger millet and related wild species was used to provide information on the origin of the genomes of this tetraploid crop and point out genetic relationships of the crop to other species in the genus. The restriction endonucleases used revealed a lack of variability in the rDNA spacer region in domesticated finger millet. All the rDNA variants of the crop were found in the proposed direct tetraploid ancestor, E. coracana subsp. africana. Wild and domesticated finger millet displayed the phenotypes found in diploid E. indica. Diploid Eleusine tristachya showed some similarity to the crop in some restriction sites. The remaining species were quite distinct in rDNA fragment patterns. The study supports the direct origin of finger millet from subspecies africana shows E. indica to be one of the genome donors of the crop, and demonstrates that none of the other species examined could have donated the second genome of the crop. The rDNA data raise the possibility that wild and domesticated finger millet could have originated as infraspecific polyploid hybrids from different varieties of E. indica.

  12. 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

  13. 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

  14. Biological availability of 238U, 234U and 226Ra for wild berries and meadow grasses in natural ecosystems of Belarus

    International Nuclear Information System (INIS)

    Sokolik, G.A.; Ovsiannikova, S.V.; Voinikava, K.V.; Ivanova, T.G.; Papenia, M.V.

    2014-01-01

    This work is devoted to investigation of behavior of 234 U, 238 U and 226 Ra by determining the soil to plant transfer under different natural conditions such as forest or swamped areas and meadow lands with different soil types. The paper summarizes the data on investigation of uranium and radium uptake by wild berries and natural meadow grasses in the typical conditions of Belarus. Parameters characterizing the biological availability of 234 U, 238 U and 226 Ra for bilberry (Vaccinium myrtillus), lingonberry (Vaccinium viti-idaea), blueberry (Vaccinium iliginosum) and cranberry (Vaccinium oxycoccus palustris) as well as for widely occurring mixed meadow vegetation, which belongs to the sedge-grass or grass-sedge associations and forbs, have been established. In the sites under investigation, the deposition levels of 238+239+240 Pu were less than 0.37 kBq m −2 and 137 Cs deposition ranged between less than 0.37 and 37 kBq m −2 . It was found that activity concentrations of radionuclides in berries varied in the ranges of 0.037–0.11 for 234 U, 0.036–0.10 for 238 U and 0.11–0.43 Bq kg −1 for 226 Ra, but in the mixed meadow grasses they were 0.32–4.4, 0.24–3.9 and 0.14–6.9 Bq kg −1 accordingly. The 234 U/ 238 U activity ratios were 1.02 ± 0.01 for wild berries, 1.20 ± 0.09 for underground meadow grasses and 1.02 ± 0.02 for proper soils. The concentration ratios (CRs, dry weight basis) of 234 U and 238 U for mixed meadow grasses were 0.036–0.42 and 0.041–0.46 respectively. The correspondent geometric means (GM) were 0.13 and 0.15 with geometric standard deviations (GSD) of 2.4. The CRs of 226 Ra for meadow grasses were 0.031–1.0 with GM 0.20 and GSD 2.6. The CRs of 234 U, 238 U and 226 Ra for wild berries ranged within 0.0018–0.008 (GM is 0.0034, GSD is 1.8), 0.0018–0.008 (GM is 0.0035, GSD is 1.8) and 0.005–0.033 (GM is 0.016, GSD is 2.1) accordingly. The highest CR values of uranium for mixed meadow grasses were found in the sites

  15. The study of desiccation-tolerance in drying leaves of the desiccation-tolerant grass Sporobolus elongatus and the desiccation-sensitive grass Sporobolus pyramidalis.

    Science.gov (United States)

    Ghasempour, Hamid Reza; Kianian, Jahanbakheshe

    2007-03-01

    Hydrated leaves of the resurrection grass Sporobolus elongatus are not desiccation tolerant (DT), but moderate to severe drought stress can induce their DT with the leaves remain attach to drying intact plants. In vivo protein synthesis was studied with SDS-page of extracts of leaves of intact drying plants of S. elongatus (a desiccation-Tolerant grass (DT)) and S. pyramidalis (a desiccation-sensitive species (DS)). Free proline increased in drying leaves. Soluble sugar contents also increased with drying but were less than fully hydrated leaves at 8% RWC. Total protein also showed an increase with an exception at 8% RWC which showed a decrease. SDS-page of extracts of drying leaves of both DT and DS plants were studied as relative water contents (RWC) decreased. In first phase, DT species at 58% RWC (80-51% RWC range), two proteins increased in contents. In the second phase, at 8% (35-4% RWC range) two new bands increased and two bands decreased. In leaves of DS species some bands decreased as drying progressed. Also, as drying advanced free proline increased in DT species. Total protein increased as drying increased but at 8% RWC decreased. All data of results are consistent with current views about studied factors and their roles during drying and induction of desiccation tolerance in DT plants.

  16. Queer families: valuing stories of adversity, diversity and belonging.

    Science.gov (United States)

    Newman, Christy E

    2018-05-31

    The 2017 Australian Marriage Law Postal Survey provided an unwelcome reminder that the concepts of queer sexuality and family life continue to be viewed as incompatible by many. However, campaigns in support of marriage equality also provide opportunities to document and disseminate stories of queer belonging within families. This commentary proposes three new ways of understanding and valuing accounts of what family means to LGBTQ communities, based on emerging findings from social research studies. It argues that in post-marriage equality contexts, it is time to learn to accept and to celebrate the differences that exist within every community, including within the diverse forms of families that are made.

  17. Patterns of species discovery in the Western Ghats, a megadiversity ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Species discovery patterns have been under study since the past ... frogs, tiger beetles, grasses, asters, ferns and orchids – in the Western Ghats, a megadiversity centre in India. Our .... This analysis is an alternative to logistic regression; it.

  18. The importance of cross-reactivity in grass pollen allergy

    Directory of Open Access Journals (Sweden)

    Aleksić Ivana

    2014-01-01

    Full Text Available According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions. [Projekat Ministarstva nauke Republike Srbije, br. 172049 i br. 172024

  19. Effect of sulfur levels on four tropical grasses in cerrado soils of mato grosso do sul, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Casagrande, J.; Correa De Souza, O.

    1982-01-01

    A greenhouse experiment was conducted to evaluate responses of four tropical grasses, Melinis minutiflora cv. Cabelo de Negro Hyparrhenia rufa, Brachiaria decumbens australian type and Setaria anceps cv. kazungula to five levels of sulfur (0, 15, 30, 45 and 60 kg/ha) in two cerrado Oxisols and one Entisol. Cuttings were done at 50, 95 and 150 days after plant exposure. Besides dry matter production, visible symptoms of sulfur deficiency were observed. Greater responses were associated with sulfur rates up to 30 kg/ha. Molasses grass and brachiaria were the most responsive species.

  20. Accelerated development in Johnsongrass seedlings (Sorghum halepense) suppresses the growth of native grasses through size-asymmetric competition.

    Science.gov (United States)

    Schwinning, Susanne; Meckel, Heather; Reichmann, Lara G; Polley, H Wayne; Fay, Philip A

    2017-01-01

    Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparius) and switchgrass (Panicum virgatum). We predicted that a) the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b) competitive effect and response would be negatively correlated and c) soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding) ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass critical mechanism by which exotic invasive species displace functionally similar native species and alter the functional dynamics of native communities.

  1. Marandu palisade grass intercropped with densely spaced teak in silvopastoral system

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Avelino Cabral

    2017-08-01

    Full Text Available This study was conducted to evaluate two systems of production: integration between teak and forage (silvopastoral system and forage only (monoculture. The forage species used was Marandu palisade grass (Urochloa brizantha cv. Marandu. In January 2009, part of the pasture was desiccated and the teak (Tectona grandis was implemented in a 3 × 4 m spacing arrangement, and at every five rows, a space between rows of 6 m was established, providing a population of 750 trees per hectare. Alongside the development of the trees, the Marandu palisade grass pasture was reestablished. In February 2015, the animals were removed from the experimental area and, in March, the pasture degradation, the density and the mass of tillers was assessed. The following variables were evaluated: sward height; forage mass, percentage of leaf blade, stem+sheath and senescent material; leaf blade:stem+sheath ratio; and live:dead material ratio. The experimental design was completely randomized, with 12 replicates. Treatments consisted of two systems (silvopastoral and monoculture. The total forage accumulation was higher in the monoculture system. The sward height and the percentage of stem+sheath were higher in the integrated system, while the percentage of leaf blade and the leaf blade:stem+sheath ratio were higher in the system exclusively with forage. In conclusion, Marandu palisade grass tolerates shading in a high density spacing silvopastoral system, but the degradation process is more intense compared to grass in monoculture, and the use of Marandu palisade grass in silvopastoral systems changes the forage mass and the structure of the produced forage.

  2. Determining the regional potential for a grass biomethane industry

    International Nuclear Information System (INIS)

    Smyth, Beatrice M.; Smyth, Henry; Murphy, Jerry D.

    2011-01-01

    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.

  3. 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

  4. 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

  5. ANATOMIC STRUCTURE OF CAMPANULA ROTUNDIFOLIA L. GRASS

    Directory of Open Access Journals (Sweden)

    V. N. Bubenchikova

    2017-01-01

    Full Text Available The article present results of the study for a anatomic structure of Campanula rotundifolia grass from Campanulaceae family. Despite its dispersion and application in folk medicine, there are no data about its anatomic structure, therefore to estimate the indices of authenticity and quality of raw materials it is necessary to develop microdiagnostical features in the first place, which could help introducing of thisplant in a medical practice. The purpose of this work is to study anatomical structureof Campanula rotundifolia grass to determine its diagnostic features. Methods. Thestudy for anatomic structure was carried out in accordance with the requirements of State Pharmacopoeia, edition XIII. Micromed laboratory microscope with digital adjutage was used to create microphotoes, Photoshop CC was used for their processing. Result. We have established that stalk epidermis is prosenchymal, slightly winding with straight of splayed end cells. After study for the epidermis cells we established that upper epidermis cells had straight walls and are slightly winding. The cells of lower epidermishave more winding walls with prolong wrinkled cuticule. Presence of simple one-cell, thin wall, rough papillose hair on leaf and stalk epidermis. Cells of epidermis in fauces of corolla are prosenchymal, with winding walls, straight or winding walls in a cup. Papillary excrescences can be found along the cup edges. Stomatal apparatus is anomocytic. Conclusion. As the result of the study we have carried out the research for Campanula rotundifolia grass anatomic structure, and determined microdiagnostic features for determination of raw materials authenticity, which included presence of simple, one-cell, thin-walled, rough papillose hair on both epidermises of a leaf, along the veins, leaf edge, and stalk epidermis, as well as the presence of epidermis cells with papillary excrescences along the edges of leaves and cups. Intercellular canals are situatedalong the

  6. Post-harvest treatments in smooth-stalked meadow grass (Poa pratensis L.) - effect on carbohydrates and tiller development

    DEFF Research Database (Denmark)

    Boelt, Birte

    2007-01-01

    Temperate grass species require a period of short days/low temperature to respond to flower induction stimuli. The same environmental conditions stimulate the increase in carbohydrate concentration in aboveground biomass and the accumulation of reserve carbohydrates in the basal plant parts....... The present investigation was initiated to investigate the effect of post-harvest treatments on dry matter production in autumn, carbohydrate content, the number of reproductive tillers and seed yield in a turf-type cultivar ‘Conni' of smooth-stalked meadow grass. The results show that post-harvest treatments...... harvest and all residues removed. The results from plant samples in autumn indicate that decreasing aboveground biomass production leads to a higher carbohydrate concentration which may stimulate the reproductive development in smooth-stalked meadow grass....

  7. Changes in nutritive value and herbage yield during extended growth intervals in grass-legume mixtures

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2018-01-01

    . Perennial ryegrass was sown with each of four legumes: red clover, white clover, lucerne and birdsfoot trefoil, and white clover was sown with hybrid ryegrass, meadow fescue and timothy. Effects of species composition on herbage yield, contents of N, neutral detergent fibre (NDF), acid detergent fibre (ADF...... in quality parameters differed among species and functional groups, i.e., grasses and legumes. Results are discussed in the context of quantifying the impact of delaying the harvest date of grass–legume mixtures and relationships between productivity and components of feed quality....

  8. 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

  9. An integral projection model with YY-males and application to evaluating grass carp control

    Science.gov (United States)

    Erickson, Richard A.; Eager, Eric A.; Brey, Marybeth; Hansen, Michael J.; Kocovsky, Patrick

    2017-01-01

    Invasive fish species disrupt ecosystems and cause economic damage. Several methods have been discussed to control populations of invasive fish including the release of YY-males. YY-males are fish that have 2 male chromosomes compared to a XY-male. When YY-males mate, they only produce male (XY) offspring. This decreases the female proportion of the population and can, in theory, eradicate local populations by biasing the sex-ratio. YY-males have been used as a population control tool for brook trout in montane streams and lakes in Idaho, USA. The YY-male control method has been discussed for grass carp in Lake Erie, North America. We developed and presented an integral projection model for grass carp to model the use of YY-males as a control method for populations in this lake. Using only the YY-male control method, we found that high levels of YY-males would need to be release annually to control the species. Specifically, these levels were the same order of magnitude as the baseline adult population (e.g., 1000 YY-males needed to be released annual for 20 years to control a baseline adult population of 2500 grass carp). These levels may not be reasonable or obtainable for fisheries managers given the impacts of YY-males on aquatic vegetation and other constraints of natural resource management.

  10. 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.

  11. Diversification of C(4) grasses (Poaceae) does not coincide with their ecological dominance.

    Science.gov (United States)

    Bouchenak-Khelladi, Yanis; Slingsby, Jasper A; Verboom, G Anthony; Bond, William J

    2014-02-01

    The radiation of a lineage and its rise to ecological dominance are distinct phenomena and driven by different processes. For example, paleoecological data has been used to show that the Cretaceous angiosperm radiation did not coincide with their rise to dominance. Using a phylogenetic approach, we here explored the evolution of C4 grasses and evaluated whether the diversification of this group and its rise to ecological dominance in the late Miocene were decoupled. We assembled a matrix including 675 grass species of the PACMAD clade and 2784 characters (ITS and ndhF) to run a molecular dating analysis using three fossils as reference calibrations. We coded species as C3 vs. C4 and reconstructed ancestral states under maximum likelihood. We used the program BiSSE to test whether rates of diversification are correlated with photosynthetic pathway and whether the radiation of C4 lineages preceded or coincided with their rise to ecological dominance from ∼10 Ma. C4 grass lineages first originated around 35 Ma at the time of the Eocene-Oligocene transition. Accelerated diversification of C4 lineages did not coincide with their rise to ecological dominance. C4-dominated grasslands have expanded only since the Late Miocene and Pliocene. The initial diversification of their biotic elements can be tracked back as far as the Eocene-Oligocene transition. We suggest that shifts in taxonomic diversification and ecological dominance were stimulated by different factors, as in the case of the early angiosperms in the Cretaceous.

  12. Forage production in mixed grazing systems of elephant grass with arrowleaf clover or forage peanut

    Directory of Open Access Journals (Sweden)

    Daiane Cristine Seibt

    Full Text Available ABSTRACT Most dairy production systems are pasture-based, usually consisting of sole grass species. This system facilitates pasture management, but results in high production costs, mainly because of nitrogen fertilizers. An alternative to making forage systems more sustainable is to introduce legumes into the pasture. Mixed pastures allow better forage distribution over time and reduce fertilization costs. Thus, the objective of this study was to evaluate, throughout the year, three forage systems (FS: FS1 (control - elephant grass (EG, ryegrass (RG, and spontaneous species (SS; FS2 - EG + RG + SS + arrowleaf clover; and FS3 - EG + RG + SS + forage peanut. Elephant grass was planted in rows spaced 4 m apart. Ryegrass was sown between the EG lines, in the winter. Arrowleaf clover was sown according to the respective treatments and forage peanut was preserved. Evaluation was carried out using Holstein cows. The experiment was arranged in a completely randomized design, with three treatments (FS, and three repetitions (paddocks with repeated measurements (grazing cycles. Forage mass achieved 3.46, 3.80, and 3.91 t ha-1 for the treatments FS1, FS2 and FS3, respectively. The forage systems intercropped with legumes produced the best results.

  13. 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.

  14. Grass-legume mixtures sustain strong yield advantage over monocultures under cool maritime growing conditions over a period of 5 years.

    Science.gov (United States)

    Helgadóttir, Áslaug; Suter, Matthias; Gylfadóttir, Thórey Ó; Kristjánsdóttir, Thórdís A; Lüscher, Andreas

    2018-05-22

    Grassland-based livestock systems in cool maritime regions are commonly dominated by grass monocultures receiving relatively high levels of fertilizer. The current study investigated whether grass-legume mixtures can improve the productivity, resource efficiency and robustness of yield persistence of cultivated grassland under extreme growing conditions over a period of 5 years. Monocultures and mixtures of two grasses (Phleum pratense and Festuca pratensis) and two legumes (Trifolium pratense and Trifolium repens), one of which was fast establishing and the other temporally persistent, were sown in a field trial. Relative abundance of the four species in the mixtures was systematically varied at sowing. The plots were maintained under three N levels (20, 70 and 220 kg N ha-1 year-1) and harvested twice a year for five consecutive years. Yields of individual species and interactions between all species present were modelled to estimate the species diversity effects. Significant positive diversity effects in all individual years and averaged across the 5 years were observed. Across years, the four-species equi-proportional mixture was 71 % (N20: 20 kg N ha-1 year-1) and 51 % (N70: 70 kg N ha-1 year-1) more productive than the average of monocultures, and the highest yielding mixture was 36 % (N20) and 39 % (N70) more productive than the highest yielding monoculture. Importantly, diversity effects were also evident at low relative abundances of either species group, grasses or legumes in the mixture. Mixtures suppressed weeds significantly better than monocultures consistently during the course of the experiment at all N levels. The results show that even in the less productive agricultural systems in the cool maritime regions grass-legume mixtures can contribute substantially and persistently to a more sustainable agriculture. Positive grass-legume interactions suggest that symbiotic N2 fixation is maintained even under these marginal conditions, provided that

  15. Herbicide spring treatments for the control of brome grasses (Bromus spp. in winter cereals

    Directory of Open Access Journals (Sweden)

    Gehring, Klaus

    2014-02-01

    Full Text Available The efficacy of different ALS-inhibiting herbicides for the control of brome species (Bromus spp. was tested in three field trials in the year 2010 – 2012 in the region of North-West-Bavaria Franken. As a result of the trials the standard herbicide Attribut (Propoxycarbazone was confirmed for the control of brome. In case of infestation with brome and black grass the herbicide Broadway (Pyroxsulam offers a certain control of both problematic grass weeds. This illustrates the high dependency of sufficient brome control in winter cereals on the effectiveness of specific ALS-Inhibitor herbicides. Because of the high risk of herbicide resistance to ACCaseand ALS-inhibiting herbicides in brome, integrated weed management is essential for the sustainable control of brome in winter cereals, respectively winter wheat.

  16. cDNA cloning and immunological characterization of the rye grass allergen Lol p I.

    Science.gov (United States)

    Perez, M; Ishioka, G Y; Walker, L E; Chesnut, R W

    1990-09-25

    The complete amino acid sequence of two "isoallergenic" forms of Lol p I, the major rye grass (Lolium perenne) pollen allergen, was deduced from cDNA sequence analysis. cDNA clones isolated from a Lolium perenne pollen library contained an open reading frame coding for a 240-amino acid protein. Comparison of the nucleotide and deduced amino acid sequence of two of these clones revealed four changes at the amino acid level and numerous nucleotide differences. Both clones contained one possible asparagine-linked glycosylation site. Northern blot analysis shows one RNA species of 1.2 kilobases. Based on the complete amino acid sequence of Lol p I, overlapping peptides covering the entire molecule were synthesized. Utilizing these peptides we have identified a determinant within the Lol p I molecule that is recognized by human leukocyte antigen class II-restricted T cells obtained from persons allergic to rye grass pollen.

  17. The Genetics of Biofuel Traits in Panicum Grasses: Developing a Model System with Diploid Panicum Hallii

    Energy Technology Data Exchange (ETDEWEB)

    Juenger, Thomas [Univ. of Texas, Austin, TX (United States). Dept. of Integrative Biology; Wolfrum, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-07-31

    Our DOE funded project focused on characterizing natural variation in C4 perennial grasses including switchgrass (Panicum virgatum) and Hall’s panicgrass (Panicum hallii). The main theme of our project was to better understand traits linked with plant performance and that impact the utility of plant biomass as a biofuel feedstock. In addition, our project developed tools and resources for studying genetic variation in Panicum hallii. Our project successfully screened both Panicum virgatum and Panicum hallii diverse natural collections for a host of phenotypes, developed genetic mapping populations for both species, completed genetic mapping for biofuel related traits, and helped in the development of genomic resources of Panicum hallii. Together, these studies have improved our understanding of the role of genetic and environmental factors in impacting plant performance. This information, along with new tools, will help foster the improvement of perennial grasses for feedstock applications.

  18. New species of Pseudagrion ( Odonata: Zygoptera) with descriptions of the larvae of five other species belonging to the genus

    CSIR Research Space (South Africa)

    Chutter, FM

    1962-01-01

    Full Text Available certaiaes conversions et sur Ia dimension de l?erreur de copie chez I?Ascobolus immersus. e outros trabalhos prometidos, mas que ainda n?o entraram para publica?ao. EDITORES C. CHAGAS A. DE B. MACHADO INSTITUT() BE BlO-EISICA MUSEU DO DUNDO AVENIDA...

  19. Identity and Belonging as Positionality. An Approach from Intersectionality

    Directory of Open Access Journals (Sweden)

    Claudia Arce-Cuadros

    2016-07-01

    Full Text Available In this article terms we may use to refer to identities and the meanings of belonging in a multicultural context are considered. For this purpose, we study Stuart Hall’s concept of vernacular cosmopolitism, which recognizes identities as points of suture between discourses and practices; that is, alignments between two scopes: a constitutive outside, and interiority produced by the self. On the other hand, we study the intersectionality approach, which considers that axes of social stratification are mutually organized and interconnected; therefore, identities are not built in relation to fixed groups such as class, ethnic group, nation, but as social positionalities letting the representation of multiple identities to operate simultaneously as possible.

  20. The need to belong can motivate belief in God.

    Science.gov (United States)

    Gebauer, Jochen E; Maio, Gregory R

    2012-04-01

    The need to belong can motivate belief in God. In Study 1, 40 undergraduates read bogus astrophysics articles "proving" God's existence or not offering proof. Participants in the proof-for-God condition reported higher belief in God (compared to control) when they chronically imagined God as accepting but lower belief in God when they imagined God as rejecting. Additionally, in Study 2 (72 undergraduates), these effects did not occur when participants' belongingness need was satisfied by priming close others. Study 3 manipulated 79 Internet participants' image of God. Chronic believers in the God-is-rejecting condition reported lower religious behavioral intentions than chronic believers in the God-is-accepting condition, and this effect was mediated by lower desires for closeness with God. In Study 4 (106 Internet participants), chronic believers with an accepting image of God reported that their belief in God is motivated by belongingness needs. © 2011 The Authors. Journal of Personality © 2012, Wiley Periodicals, Inc.

  1. Acetogenic and Sulfate-Reducing Bacteria Inhabiting the Rhizoplane and Deep Cortex Cells of the Sea Grass Halodule wrightii†

    Science.gov (United States)

    Küsel, Kirsten; Pinkart, Holly C.; Drake, Harold L.; Devereux, Richard

    1999-01-01

    Recent declines in sea grass distribution underscore the importance of understanding microbial community structure-function relationships in sea grass rhizospheres that might affect the viability of these plants. Phospholipid fatty acid analyses showed that sulfate-reducing bacteria and clostridia were enriched in sediments colonized by the sea grasses Halodule wrightii and Thalassia testudinum compared to an adjacent unvegetated sediment. Most-probable-number analyses found that in contrast to butyrate-producing clostridia, acetogens and acetate-utilizing sulfate reducers were enriched by an order of magnitude in rhizosphere sediments. Although sea grass roots are oxygenated in the daytime, colorimetric root incubation studies demonstrated that acetogenic O-demethylation and sulfidogenic iron precipitation activities were tightly associated with washed, sediment-free H. wrightii roots. This suggests that the associated anaerobes are able to tolerate exposure to oxygen. To localize and quantify the anaerobic microbial colonization, root thin sections were hybridized with newly developed 33P-labeled probes that targeted (i) low-G+C-content gram-positive bacteria, (ii) cluster I species of clostridia, (iii) species of Acetobacterium, and (iv) species of Desulfovibrio. Microautoradiography revealed intercellular colonization of the roots by Acetobacterium and Desulfovibrio species. Acetogenic bacteria occurred mostly in the rhizoplane and outermost cortex cell layers, and high numbers of sulfate reducers were detected on all epidermal cells and inward, colonizing some 60% of the deepest cortex cells. Approximately 30% of epidermal cells were colonized by bacteria that hybridized with an archaeal probe, strongly suggesting the presence of methanogens. Obligate anaerobes within the roots might contribute to the vitality of sea grasses and other aquatic plants and to the biogeochemistry of the surrounding sediment. PMID:10543830

  2. From pasture grass to cattle milk

    International Nuclear Information System (INIS)

    Miyamoto, Susumu

    1979-01-01

    Iodine-131 is one of the important fission products since it is selectively accumulated in the thyroid gland of man. The transfer of this isotope from contaminated grass to cows' milk is therefore of particular importance since milk is a major constituent of the diet especially for infants. The purpose of this paper is to discuss the transfer rate of this isotope from grass to milk of lactuating cows and its distribution in milk. It is said that the orally administered iodide is rapidly absorbed through the rumen wall and excreted mainly to urine. The absorbed iodine is accumulated highly in the thyroid gland and the considerable amount is secreted to milk. Garner et al. showed that about 5% of a dose of 131 I was found in the milk within 7 days. The extremes were 1.43 to 16.4%. Present author obtained that 18 - 30% of the dosed 131 I was secreted into milk within 7 days, indicating somewhat higher transfer rate than that of Garner et al. It was reported that more than 90% of 131 I was found in milk serum in the ionic form. The countermeasures for diminishing 131 I in milk were also presented. (author)

  3. 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.

  4. Using expansive grasses for monitoring heavy metal pollution in the vicinity of roads.

    Science.gov (United States)

    Vachová, Pavla; Vach, Marek; Najnarová, Eva

    2017-10-01

    We propose a method for monitoring heavy metal deposition in the vicinity of roads using the leaf surfaces of two expansive grass species which are greatly abundant. A principle of the proposed procedure is to minimize the number of operations in collecting and preparing samples for analysis. The monitored elements are extracted from the leaf surfaces using dilute nitric acid directly in the sample-collection bottle. The ensuing steps, then, are only to filter the extraction solution and the elemental analysis itself. The verification results indicate that the selected grasses Calamagrostis epigejos and Arrhenatherum elatius are well suited to the proposed procedure. Selected heavy metals (Zn, Cu, Pb, Ni, Cr, and Cd) in concentrations appropriate for direct determination using methods of elemental analysis can be extracted from the surface of leaves of these species collected in the vicinity of roads with medium traffic loads. Comparing the two species showed that each had a different relationship between the amounts of deposited heavy metals and distance from the road. This disparity can be explained by specific morphological properties of the two species' leaf surfaces. Due to the abundant occurrence of the two species and the method's general simplicity and ready availability, we regard the proposed approach to constitute a broadly usable and repeatable one for producing reproducible results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Are biodiversity indices of spontaneous grass covers in olive orchards good indicators of soil degradation?

    Science.gov (United States)

    Taguas, E. V.; Arroyo, C.; Lora, A.; Guzmán, G.; Vanderlinden, K.; Gómez, J. A.

    2015-03-01

    Spontaneous grass covers are an inexpensive soil erosion control measure in olive orchards. Olive farmers allow grass to grow on sloping terrain to comply with the basic environmental standards derived from the Common Agricultural Policy (CAP). However, to date there are very few studies assessing the environmental quality and extent of such covers. In this study, we described and compared the biodiversity indicators associated to herbaceous vegetation in two contrasting olive orchards in order to evaluate its relevance and quality. In addition, biodiversity patterns and their relationships with environmental factors such as soil type and properties, precipitation, topography and soil management were analyzed. Different grass cover biodiversity indices were evaluated in two olive orchard catchments under conventional tillage and no tillage with grass cover, during 3 hydrological years (2011-2013). Seasonal samples of vegetal material and pictures in a permanent grid (4 samples ha-1) were taken to characterize the temporal variations of the number of species, frequency, diversity and transformed Shannon's and Pielou's indices. Sorensen's index obtained in the two olive orchard catchments showed notable differences in composition, probably linked with the different site conditions. The catchment with the best site conditions (deeper soil and higher precipitation), with average annual soil losses over 10 t ha-1 and a more intense management, presented the highest biodiversity indices. In absolute terms, the diversity indices were reasonably high in both catchments, despite the fact that agricultural activity usually severely limits the landscape and the variety of species. Finally, a significantly higher content of organic matter in the first 10 cm of soil was found in the catchment with the worst site conditions, average annual soil losses of 2 t ha-1 and the least intense management. Therefore, the biodiversity indicators associated to weeds were not found to be

  6. Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

    Science.gov (United States)

    Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.

    2018-01-01

    Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production

  7. Perennial Grass Bioenergy Cropping on Wet Marginal Land

    NARCIS (Netherlands)

    Das, Srabani; Teuffer, Karin; Stoof, Cathelijne R.; Walter, Michael F.; Walter, M.T.; Steenhuis, Tammo S.; Richards, Brian K.

    2018-01-01

    The control of soil moisture, vegetation type, and prior land use on soil health parameters of perennial grass cropping systems on marginal lands is not well known. A fallow wetness-prone marginal site in New York (USA) was converted to perennial grass bioenergy feedstock production. Quadruplicate

  8. No positive feedback between fire and a nonnative perennial grass

    Science.gov (United States)

    Erika L. Geiger; Guy R. McPherson

    2005-01-01

    Semi-desert grasslands flank the “Sky Island” mountains in southern Arizona and Northern Mexico. Many of these grasslands are dominated by nonnative grasses, which potentially alter native biotic communities. One specific concern is the potential for a predicted feedback between nonnative grasses and fire. In a large-scale experiment in southern Arizona we investigated...

  9. Analysis of Fusarium causing dermal toxicosis in marram grass planters

    NARCIS (Netherlands)

    Snijders, CHA; Samson, RA; Hoekstra, ES; Ouellet, T; Miller, JD; deRooijvanderGoes, PCEM; Baar, AJM; Dubois, AEJ; Kauffman, HF

    1996-01-01

    In the European coastal dunes, marram grass (Ammophila arenaria) is planted in order to control sand erosion. In the years 1986 to 1991, workers on the Wadden islands in the Netherlands planting marram grass showed lesions of skin and mucous membranes, suggesting a toxic reaction. Fusarium culmorum

  10. Conceptual model for reinforced grass on inner dike slopes

    NARCIS (Netherlands)

    Verhagen, H.J.; 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

  11. Grass defoliation affecting survival and growth of seedlings of ...

    African Journals Online (AJOL)

    Two experiments were conducted, one in the field and the other in the greenhouse, to investigate the effects of the intensity and frequency of grass defoliation on the survival and growth of Acacia karroo seedlings. In the greenhouse, seedlings growing with heavily clipped grasses had higher biomass production than those ...

  12. Defoliation effects of perennial grasses – continuing confusion | DL ...

    African Journals Online (AJOL)

    Although an adequate knowledge of growth patterns and defoliation effects in perennial grasses is a prerequisite for the rational use of veld and pastures for animal production, our knowledge of this subject is far from adequate. The results of various physiological and clipping studies on tropical and sub-tropical grasses are ...

  13. 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.

  14. EBIPM | Finding the Tools to Manage Invasive Annual Grasses

    Science.gov (United States)

    management decisions for a given landscape based on ecological principles. Take a look at our video " Grass Management How much could prevention save you? Guidelines to Implement EBIPM Weed Prevention Areas Grass Facts/ID The EBIPM Model Crooked River Weed Management Area Guide Tools for Educators EBIPM High

  15. Lessons learned in managing alfalfa-grass mixtures

    Science.gov (United States)

    Grass-alfalfa mixtures have a number of benefits that make them attractive to producers. However, they can be problematic to establish and maintain. Research programs have made progress in understanding the benefits and challenges of alfalfa-grass mixtures. Mixtures may have greater winter survival ...

  16. Agricultural field reclamation utilizing native grass crop production

    Science.gov (United States)

    J. Cure

    2013-01-01

    Developing a method of agricultural field reclamation to native grasses in the Lower San Pedro Watershed could prove to be a valuable tool for educational and practical purposes. Agricultural field reclamation utilizing native grass crop production will address water table depletion, soil degradation and the economic viability of the communities within the watershed....

  17. Analysis of Some Heavy Metals in Grass ( Paspalum Orbiculare ...

    African Journals Online (AJOL)

    The increased deposition of trace metals from vehicle exhausts on plants has raised concerns about the risks of the quality of food consumed by humans since the heavy metals emitted through the exhaust by vehicles can enter food chain through deposition on grass grazed by animals. Grass (Paspalum Orbiculare) and ...

  18. Invasive grasses change landscape structure and fire behavior in Hawaii

    Science.gov (United States)

    Lisa M. Ellsworth; Creighton M. Litton; Alexander P. Dale; Tomoaki Miura

    2014-01-01

    How does potential fire behavior differ in grass-invaded non-native forests vs open grasslands? How has land cover changed from 1950–2011 along two grassland/forest ecotones in Hawaii with repeated fires? A study on non-native forest with invasive grass understory and invasive grassland (Megathyrsus maximus) ecosystems on Oahu, Hawaii, USA was...

  19. ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF PLANTS BELONGING TO LAMIACEAE JUSS. FAMILY

    Directory of Open Access Journals (Sweden)

    Shanayda M.I.

    2015-12-01

    Full Text Available Introduction. One of the important sources of therapeutic and prophylactic agents of modern medicines are essential oils of medicinal plants. Essential oils are the main group of biologically active substances of a number of plants belonging to Lamiaceae Juss. Family. Antibacterial activity of medicinal plants belonging to Lamiaceae Family many scientists associated with containing of essential oils. In this regard, considerable interest presents the comparative analysis of the antimicrobial properties of essential oils of Lamiaceae Family representatives. Material and methods.The antimicrobial activity of essential oils of investigated plants was studied with using in vitro condition. The essential oils derived from the aerial parts of cultivated plants of Ocimum, Hyssopus, Dracocephalum, Lophanthus, Monarda and Satureja genus harvested during flowering period (in terms of Ternopil region. The antimicrobial activity of essential oils studied plants was studied by serial dilution method and disk diffusion assay. It has been applied on standard microorganism test strains: Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 885-653. Results and discussion. It was conducted a comparative study of the influence of some essential oils of cultivated plants belonging to Lamiaceae family on microorganisms in conditions in vitro. It was found that essential oils of the studied plants were most effective in the maximum concentration (1:10. Gram-positive cocci S. aureus and yeast C. albicans were the most sensitive to influence of investigated essential oils. It was analyzed the relationship of the biological activity with the component composition of essential oils of plants. Essential oils of L. anisatus, M. fistulosa and S. hortensis characterized by the dominance of aromatic compounds and had shown stronger antimicrobial activity than essential oils of

  20. 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.

  1. Rumen escape protein in grass and grass silage deterimened with a nylon bag and an enzymatic technique

    NARCIS (Netherlands)

    Cone, J.W.; Gelder, van A.H.; Mathijssen-Kamman, A.A.; Hindle, V.A.

    2004-01-01

    Rumen escape protein (REP) was determined for six grasses and 16 grass silages using a nylon bag technique and an in vitro technique using a proteolytic enzyme preparation of Streptomyces griseus. In vitro, the samples were incubated for 0, 1, 6 and 24 h. The highest correlation observed between

  2. EroGRASS : Failure of grass cover layers at seaward and shoreward dike slopes. design, construction and performance

    NARCIS (Netherlands)

    Verhagen, H.J.; Verheij, H.J.; Cao, T.M.; Dassanayake, D.; Roelvink, D.; Piontkowitz, T.

    2009-01-01

    A large number of the dikes in the North Sea and Baltic Sea regions are covered with grass that is exposed to hydraulic loading from waves and currents during storm surges. During previous storm surges the grass cover layers often showed large strength and remained undamaged. A clear physical

  3. Established native perennial grasses out-compete an invasive annual grass regardless of soil water and nutrient availability

    Science.gov (United States)

    Christopher M. McGlone; Carolyn Hull Sieg; Thomas E. Kolb; Ty Nietupsky

    2012-01-01

    Competition and resource availability influence invasions into native perennial grasslands by nonnative annual grasses such as Bromus tectorum. In two greenhouse experiments we examined the influence of competition, water availability, and elevated nitrogen (N) and phosphorus (P) availability on growth and reproduction of the invasive annual grass B. tectorum and two...

  4. Genome sequencing and comparative genomics analysis revealed pathogenic potential in Penicillium capsulatum as a novel fungal pathogen belonging to Eurotiales

    Directory of Open Access Journals (Sweden)

    Ying Yang

    2016-10-01

    Full Text Available Penicillium capsulatum is a rare Penicillium species used in paper manufacturing, but recently it has been reported to cause invasive infection. To research the pathogenicity of the clinical Penicillium strain, we sequenced the genomes and transcriptome of the clinical and environmental strains of P. capsulatum. Comparative analyses of these two P. capsulatum strains and close related strains belonging to Eurotiales were performed. The assembled genome sizes of P. capsulatum are approximately 34.4 Mbp in length and encode 11,080 predicted genes. The different isolates of P. capsulatum are highly similar, with the exception of several unique genes, INDELs or SNP in the genes coding for glycosyl hydrolases, amino acid transporters and circumsporozoite protein. A phylogenomic analysis was performed based on the whole genome data of 38 strains belonging to Eurotiales. By comparing the whole genome sequences and the virulence-related genes from 20 important related species, including fungal pathogens and non-human pathogens belonging to Eurotiales, we found meaningful pathogenicity characteristics between P. capsulatum and its closely related species. Our research indicated that P. capsulatum may be a neglected opportunistic pathogen. This study is beneficial for mycologists, geneticists and epidemiologists to achieve a deeper understanding of the genetic basis of the role of P. capsulatum as a newly reported fungal pathogen.

  5. Cercosporoid fungi (Mycosphaerellaceae) 2. Species on monocots (Acoraceae to Xyridaceae, excluding Poaceae).

    Science.gov (United States)

    Braun, Uwe; Crous, Pedro W; Nakashima, Chiharu

    2014-12-01

    Cercosporoid fungi (formerly Cercospora s. lat.) represent one of the largest groups of hyphomycetes belonging to the Mycosphaerellaceae (Ascomycota). They include asexual morphs, asexual holomorphs, or species with mycosphaerella-like sexual morphs. Most of them are leaf-spotting plant pathogens with special phytopathological relevance. In the first part of a new monographic work, cercosporoid hyphomycetes occurring on other fungi (fungicolous species), on ferns (pteridophytes) and gymnosperms were treated. This second part deals with cercosporoid fungi on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), which covers species occurring on host plants belonging to families arranged in alphabetical order from Acoraceae to Xyridaceae, excluding Poaceae (cereals and grasses) which requires a separate treatment. The species are described and illustrated in alphabetical order under the particular cercosporoid genera, supplemented by keys to the species concerned. A detailed introduction, a survey of currently recognised cercosporoid genera, a key to the genera concerned, and a discussion of taxonomically relevant characters were published in the first part of this series. Neopseudocercospora, an additional recently introduced cercosporoid genus, is briefly discussed. The following taxonomic novelties are introduced: Cercospora alpiniigena sp. nov., C. neomaricae sp. nov., Corynespora palmicola comb. nov., Exosporium miyakei comb. nov., E. petersii comb. nov., Neopseudocercospora zambiensis comb. nov., Passalora caladiicola comb. nov., P. streptopi comb. nov., P. togashiana comb. nov., P. tranzschelii var. chinensis var. nov., Pseudocercospora beaucarneae comb. nov., P. constrictoflexuosa comb. et stat. nov., P. curcumicola sp. nov., P. dispori comb. nov., P. smilacicola sp. nov., P. urariigena nom. nov., Zasmidium agavicola comb. nov., Z. cercestidis-afzelii comb. nov., Z. citri-griseum comb. nov., Z. cyrtopodii comb. nov., Z. gahnae comb. nov., Z. indicum

  6. A review on mesopelagic fishes belonging to family Myctophidae

    Digital Repository Service at National Institute of Oceanography (India)

    Catul, V.; Gauns, M.; Karuppasamy, P.K.

    Jr (1991) Life histories of three species of lanternfishes (Pisces: Myctophidae) from the eastern Gulf of Mexico. II- Age and growth patterns. Mar Biol 111:21-27 Gjөsæter J (1984) Mesopelagic fish, a large potential resource in the Arabian Sea. Deep...

  7. On an undescribed Cetoniid belonging to the genus Chalcothea, Burm

    NARCIS (Netherlands)

    Ritsema Cz., C.

    1882-01-01

    Amongst the specimens of Chalcothea smaragdina G. & P. ¹) of the Leyden Museum, I lately found a female specimen from Sumatra of a distinct although nearly allied species, which, as I am informed by Mr. van Lansberge, bears in several, especially french collections the name of Chalcothea affinis

  8. Urban foraging and the relational ecologies of belonging

    Science.gov (United States)

    Melissa R. Poe; Joyce LeCompte; Rebecca McLain; Patrick T. Hurley

    2014-01-01

    Through a discussion of urban foraging in Seattle, Washington, USA, we examine how people’s plant and mushroom harvesting practices in cities are linked to relationships with species, spaces, and ecologies. Bringing a relational approach to political ecology, we discuss the ways that these particular nature–society relationships are formed, legitimated, and mobilized...

  9. Biogeography of thermophilic phototrophic bacteria belonging to Roseiflexus genus.

    Science.gov (United States)

    Gaisin, Vasil A; Grouzdev, Denis S; Namsaraev, Zorigto B; Sukhacheva, Marina V; Gorlenko, Vladimir M; Kuznetsov, Boris B

    2016-03-01

    Isolated environments such as hot springs are particularly interesting for studying the microbial biogeography. These environments create an 'island effect' leading to genetic divergence. We studied the phylogeographic pattern of thermophilic anoxygenic phototrophic bacteria, belonging to the Roseiflexus genus. The main characteristic of the observed pattern was geographic and geochronologic fidelity to the hot springs within Circum-Pacific and Alpine-Himalayan-Indonesian orogenic belts. Mantel test revealed a correlation between genetic divergence and geographic distance among the phylotypes. Cluster analysis revealed a regional differentiation of the global phylogenetic pattern. The phylogeographic pattern is in correlation with geochronologic events during the break up of Pangaea that led to the modern configuration of continents. To our knowledge this is the first geochronological scenario of intercontinental prokaryotic taxon divergence. The existence of the modern phylogeographic pattern contradicts with the existence of the ancient evolutionary history of the Roseiflexus group proposed on the basis of its deep-branching phylogenetic position. These facts indicate that evolutionary rates in Roseiflexus varied over a wide range. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. 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.

  11. Vegetative hyphal fusion and subsequent nuclear behavior in Epichloë grass endophytes.

    Science.gov (United States)

    Shoji, Jun-Ya; Charlton, Nikki D; Yi, Mihwa; 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 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.

  12. Perrenial Grasses for Sustainable European Protein Production

    DEFF Research Database (Denmark)

    Jørgensen, Uffe; Lærke, Poul Erik

    2016-01-01

    reduction goals for agriculture. Denmark has an especially vulnerable aquatic environment due to sandy soils, a long coast line, and high precipitation. Thus, fulfilling the WFD means some areas must halve their nitrate leaching, and radical changes are required to reduce losses while maintaining profitable...... crop production. National scenarios show that up to ten million tonnes of additional biomass can be sourced in Denmark without reducing food production or increasing the area under cultivation if a biorefinery industry is established. In one of the scenarios optimized for additional environmental...... in the “environment” scenario. This scenario was achieved by converting approx. 9 % of agricultural land from annual crops into perennial grass. New experimental results support the anticipated increase in total biomass yield and reduction in nitrate leaching, when converting land currently used for grain crop...

  13. Accelerated development in Johnsongrass seedlings (Sorghum halepense suppresses the growth of native grasses through size-asymmetric competition.

    Directory of Open Access Journals (Sweden)

    Susanne Schwinning

    Full Text Available Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense, big bluestem (Andropogon gerardii, little bluestem (Schizachyrium scoparius and switchgrass (Panicum virgatum. We predicted that a the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b competitive effect and response would be negatively correlated and c soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass < big bluestem < little bluestem/switchgrass, while Johnsongrass responded more strongly to competition from Johnsongrass than from native species. At final harvest, native plants growing with Johnsongrass attained between 2-5% of their single-plant non-root biomass, while Johnsongrass growing with native species attained 89% of single-plant non-root biomass. Fertilization enhanced Johnsongrass' competitive effects on native species, but added little to the already severe competitive suppression. Accelerated early growth of Johnsongrass seedlings relative to native seedlings appeared to enable subsequent resource pre-emption. Size-asymmetric competition and resource

  14. Cool-Season Turfgrass Species and Cultivars: Response to Simulated Traffic in Central Italy

    Directory of Open Access Journals (Sweden)

    Carlo F. Cereti

    2010-03-01

    Full Text Available Turfgrass species differ greatly in their ability to withstand the abrasion and compaction of traffic. Wear tolerance of turfgrass species and cultivars has been evaluated abroad by many researchers, while only few and partial studies have been conducted in Italy. Field experiment was carried out in Viterbo in 2001, 2002 and 2003 to evaluate the effect of the simulated traffic on 110 varieties belonging to four turfgrass cool-season species: tall fescue (Festuca arundinacea Schreb., fine fescues (Festuca rubra L. ssp. rubra Gaud., ssp. commutata Gaud., ssp. tricophylla Gaud., perennial ryegrass (Lolium perenne L. and Kentucky bluegrass (Poa pratensis L.. Shoot density, visual turfgrass quality and thatch thickness were the major characters recorded to estimate wear tolerance. Traffic was simulated using a device containing three rollers pulled by a small tractor. The traffic simulator weighed 564 kg and applied a pressure of about 3 MPa. Results indicated that perennial ryegrass and tall fescue had high wear tolerance and low statistical variation among cultivars. Kentucky bluegrass showed an average wear tolerance owing to its shoot density and good recovery potential. In spite of their high shoot density, fine fescues exhibited poor wear tolerance because of their scarce resistance to high temperatures which are typical of the Mediterranean climate in late spring and summer. This study enabled a preliminary selection of the most suitable cool-season grasses and cultivars for trafficked and non-trafficked areas in Central Italy and highlighted that different turfgrass species have different wear tolerance mechanisms.

  15. Autopolyploids in fodder grass breeding: induction and field performance

    Energy Technology Data Exchange (ETDEWEB)

    Dabkevičienė, G.; Kemešytė, V.; Statkevičiūtė, G.; Lemežienė, N.; Brazauskas, G.

    2017-07-01

    Doubling of chromosome set directly affects plant performance through increase of organ size, higher feeding value and increased resistance to adverse environmental factors. Therefore efficient methods of polyploid induction are needed in order to develop new varieties of naturally diploid fodder grass species. The efficiency of antimitotic agents as colchicine, amiprophos-methyl, trifluralin and oryzalin was compared in a series of tetraploid induction experiments in Lolium multiflorum, L. perenne and Festuca pratensis, while newly developed tetraploid plants were compared to standard tetraploid varieties in the field trials. Colchicine treatment proved to be the most efficient method for in vitro cultured embryos in comparison with the other agents. Induced tetraploids of F. pratensis produced higher dry matter and seed yield and could be used for the development of new varieties. Induced tetraploid plants of Lolium spp. were equal to the standard varieties in field trials, therefore they could be used as parental genotypes in crosses. Induced tetraploids of F. pratensis produced higher dry matter and seed yield and could be used for development of new variety.

  16. Application of wood chips for soil mulching in the cultivation of ornamental grasses

    Directory of Open Access Journals (Sweden)

    Henschke Monika

    2016-12-01

    Full Text Available A mulch is a layer of material applied to the surface of the soil. Mulching plays an important role in the maintenance of green spaces. Organic materials are still sought for the preparation of mulches. Recently interest in wood chips has grown. The aim of the study was to determine the effect of mulching with pine and birch chips on the contents of phenolic compounds in the soil, as well as on the growth and flowering of ornamental grasses – Bouteloua gracilis (Kunth. Lag. ex Griffiths, Panicum virgatum L. and Pennisetum alopecuroides L. The content of phenolic compounds in the soil steadily increased from spring to autumn. Mulching led to a substantial increase in the level of phenolic compounds. In the first year of cultivation more phenolic compounds were released by chips of pine than birch, while in the second year this difference did not occur. Mulching had a negative impact on the growth and flowering of ornamental grasses, especially in the first year of cultivation. Ornamental grass sensitivity to the substances released from mulches decreased with the age of the plants and was dependent on the species – Bouteloua gracilis was found to be particularly sensitive.

  17. Setaria viridis and Setaria italica, model genetic systems for the Panicoid grasses.

    Science.gov (United States)

    Li, Pinghua; Brutnell, Thomas P

    2011-05-01

    Setaria italica and its wild ancestor Setaria viridis are diploid C(4) grasses with small genomes of ∼515 Mb. Both species have attributes that make them attractive as model systems. Setaria italica is a grain crop widely grown in Northern China and India that is closely related to the major food and feed crops maize and sorghum. A large collection of S. italica accessions are available and thus opportunities exist for association mapping and allele mining for novel variants that will have direct application in agriculture. Setaria viridis is the weedy relative of S. italica with many attributes suitable for genetic analyses including a small stature, rapid life cycle, and prolific seed production. Setaria sp. are morphologically similar to most of the Panicoideae grasses, including major biofuel feedstocks, switchgrass (Panicum virgatum) and Miscanthus (Miscanthus giganteus). They are broadly distributed geographically and occupy diverse ecological niches. The cross-compatibility of S. italica and S. viridis also suggests that gene flow is likely between wild and domesticated accessions. In addition to serving as excellent models for C(4) photosynthesis, these grasses provide novel opportunities to study abiotic stress tolerance and as models for bioenergy feedstocks.

  18. Uptake of C14-atrazine by prairie grasses in a phytoremediation setting.

    Science.gov (United States)

    Khrunyk, Yuliya; Schiewer, Silke; Carstens, Keri L; Hu, Dingfei; Coats, Joel R

    2017-02-01

    Agrochemicals significantly contribute to environmental pollution. In the USA, atrazine is a widely used pesticide and commonly found in rivers, water systems, and rural wells. Phytoremediation can be a cost-effective means of removing pesticides from soil. The objective of this project was to investigate the ability of prairie grasses to remove atrazine. 14 C-labeled atrazine was added to sterilized sand and water/nutrient cultures, and the analysis was performed after 21 days. Switchgrass and big bluestem were promising species for phytoremediation, taking up about 40% of the applied [ 14 C] in liquid hydroponic cultures, and between 20% and 33% in sand cultures. Yellow Indiangrass showed low resistance to atrazine toxicity and low uptake of [ 14 C] atrazine in liquid hydroponic cultures. Atrazine degradation increased progressively from sand to roots and leaves. Most atrazine taken up by prairie grasses from sand culture was degraded to metabolites, which accounted for 60-80% of [ 14 C] detected in leaves. Deisopropylatrazine (DIA) was the main metabolite detected in sand and roots, whereas in leaves further metabolism took place, forming increased amounts of didealkylatrazine (DDA) and an unidentified metabolite. In conclusion, prairie grasses achieved high atrazine removal and degradation, showing a high potential for phytoremediation.

  19. 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

  20. 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.

  1. Feasibility of Invasive Grass Detection in a Desertscrub Community Using Hyperspectral Field Measurements and Landsat TM Imagery

    Directory of Open Access Journals (Sweden)

    Stuart E. Marsh

    2011-10-01

    Full Text Available Invasive species’ phenologies often contrast with those of native species, representing opportunities for detection of invasive species with multi-temporal remote sensing. Detection is especially critical for ecosystem-transforming species that facilitate changes in disturbance regimes. The African C4 grass, Pennisetum ciliare, is transforming ecosystems on three continents and a number of neotropical islands by introducing a grass-fire cycle. However, previous attempts at discriminating P. ciliare in North America using multi-spectral imagery have been unsuccessful. In this paper, we integrate field measurements of hyperspectral plant species signatures and canopy cover with multi-temporal spectral analysis to identify opportunities for detection using moderate-resolution multi-spectral imagery. By applying these results to Landsat TM imagery, we show that multi-spectral discrimination of P. ciliare in heterogeneous mixed desert scrub is feasible, but only at high abundance levels that may have limited value to land managers seeking to control invasion. Much higher discriminability is possible with hyperspectral shortwave infrared imagery because of differences in non-photosynthetic vegetation in uninvaded and invaded landscapes during dormant seasons but these spectra are unavailable in multispectral sensors. Therefore, we recommend hyperspectral imagery for distinguishing invasive grass-dominated landscapes from uninvaded desert scrub.

  2. Environmental performance assessment of Napier grass for bioenergy production

    DEFF Research Database (Denmark)

    Nimmanterdwong, Prathana; Chalermsinsuwan, Benjapon; Østergård, Hanne

    2017-01-01

    equivalence. This idea provides the quantitative indicators involving the resource use and the percent renewability of the systems. For the proposed biorefinery model, Napier grass (Pennisetum purpureum) grown in Thailand was used as lignocellulosic feedstock. An emergy assessment was performed in two parts...... cultivation and biorefinery stages. For Napier grass cultivation, most of the emergy support came from local resources in term of evapotranspiration of Napier grass (33%) and the diesel consumption during the cultivation process (21%). The emergy sustainability indicator of the cultivation was 0...

  3. Biohydrogenation of Fatty Acids Is Dependent on Plant Species and Feeding Regimen of Dairy Cows

    DEFF Research Database (Denmark)

    Petersen, Majbritt Bonefeld; Jensen, Søren Krogh

    2014-01-01

    and LA between single plant species and feeding regimens. Rumen fluid was collected from cows fed either total mixed ration (TMR), species-rich silage (HERB), or grass silage (GRASS). Five single species (alfalfa, birdsfoot trefoil, chicory, English plantain, and salad burnet) and a grass–clover mixture...... (white clover and ryegrass) were incubated in three replicas up to 30 h and subsequently analyzed for fatty acid content. Michaelis–Menten kinetics was applied for quantifying the BH rate. BH proceeded at the lowest rate in alfalfa and salad burnet (P ... was lower in HERB and GRASS compared to TMR (P

  4. Diversity and incidence of plant-parasitic nematodes in Belgian turf grass

    NARCIS (Netherlands)

    Vandenbossche, B.; Viaene, N.; Sutter, de N.; Maes, M.; Karssen, G.; Bert, W.

    2011-01-01

    Eleven golf courses and eight football pitches, located in Belgium, were surveyed for plant-parasitic nematodes. This revealed a remarkably high diversity: 52 different species/taxa were identified morphologically, belonging to 23 genera and nine families. Among the most prevalent nematodes on both

  5. Aquatic Nuisance Species Locator

    Science.gov (United States)

    Data in this map has been collected by the United States Geological Survey's Nonindigenous Aquatic Species program located in Gainesville, Florida (http://nas.er.usgs.gov/default.aspx). This dataset may have some inaccuracies and is only current to June 15, 2012. The species identified in this dataset are not inclusive of all aquatic nuisance species, but rather a subset identified to be at risk for transport by recreational activities such as boating and angling. Additionally, the locations where organisims have been identified are also not inclusive and should be treated as a guide. Organisms are limited to the following: American bullfrog, Asian clam, Asian shore crab, Asian tunicate, Australian spotted jellyfish, Chinese mitten crab, New Zealand mudsnail, Colonial sea squirt, Alewife, Bighead carp, Black carp, Flathead catfish, Grass carp, Green crab, Lionfish, Northern snakehead, Quagga mussel, Round Goby, Ruffe, Rusty crayfish, Sea lamprey, Silver carp, Spiny water flea, Veined rapa whelk, Zebra mussel

  6. Testing efficacy of distance and tree-based methods for DNA barcoding of grasses (Poaceae tribe Poeae) in Australia.

    Science.gov (United States)

    Birch, Joanne L; Walsh, Neville G; Cantrill, David J; Holmes, Gareth D; Murphy, Daniel J

    2017-01-01

    In Australia, Poaceae tribe Poeae are represented by 19 genera and 99 species, including economically and environmentally important native and introduced pasture grasses [e.g. Poa (Tussock-grasses) and Lolium (Ryegrasses)]. We used this tribe, which are well characterised in regards to morphological diversity and evolutionary relationships, to test the efficacy of DNA barcoding methods. A reference library was generated that included 93.9% of species in Australia (408 individuals, [Formula: see text] = 3.7 individuals per species). Molecular data were generated for official plant barcoding markers (rbcL, matK) and the nuclear ribosomal internal transcribed spacer (ITS) region. We investigated accuracy of specimen identifications using distance- (nearest neighbour, best-close match, and threshold identification) and tree-based (maximum likelihood, Bayesian inference) methods and applied species discovery methods (automatic barcode gap discovery, Poisson tree processes) based on molecular data to assess congruence with recognised species. Across all methods, success rate for specimen identification of genera was high (87.5-99.5%) and of species was low (25.6-44.6%). Distance- and tree-based methods were equally ineffective in providing accurate identifications for specimens to species rank (26.1-44.6% and 25.6-31.3%, respectively). The ITS marker achieved the highest success rate for specimen identification at both generic and species ranks across the majority of methods. For distance-based analyses the best-close match method provided the greatest accuracy for identification of individuals with a high percentage of "correct" (97.6%) and a low percentage of "incorrect" (0.3%) generic identifications, based on the ITS marker. For tribe Poeae, and likely for other grass lineages, sequence data in the standard DNA barcode markers are not variable enough for accurate identification of specimens to species rank. For recently diverged grass species similar challenges are

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Steve A. [Scripps Research Inst., La Jolla, CA (United States); Hazen, Samuel [Scripps Research Inst., San Diego, CA (United States); Mullet, John [Texas A & M Univ., College Station, TX (United States)

    2017-11-22

    Critical to the development of renewable energy sources from biofuels is the improvement of biomass from energy feedstocks, such as sorghum and maize. The specific goals of this project include 1) characterize the growth and gene expression patterns under diurnal and circadian conditions, 2) select transcription factors associated with growth and build a cis-regulatory network in yeast, and 3) perturb these transcription factors in planta using transgenic Brachypodium and sorghum, and characterize the phenotypic outcomes as they relate to biomass accumulation. 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.

  9. Competition for phosphorus: differential uptake from dual-isotope-labeled soil interspaces between shrub and grass

    International Nuclear Information System (INIS)

    Caldwell, M.M.; Eissenstat, D.M.; Richards, J.H.; Allen, M.F.

    1985-01-01

    Two species of Agropyron grass differed strikingly in their capacity to compete for phosphate in soil interspaces shared with a common competitor, the sagebrush Artemisia tridentata. Of the total phosphorus-32 and -33 absorbed by Artemisia, 86% was from the interspace shared with Agropyron spicatum and only 14% from that shared with Agropyron desertorum. Actively absorbing mycorrhizal roots of Agropyron and Artemisia were present in both interspaces, where competition for the labeled phosphate occurred. The results have important implications about the way in which plants compete for resources below ground in both natural plant communities and agricultural intercropping systems

  10. Spreaders, igniters, and burning shrubs: plant flammability explains novel fire dynamics in grass-invaded deserts.

    Science.gov (United States)

    Fuentes-Ramirez, Andres; Veldman, Joseph W; Holzapfel, Claus; Moloney, Kirk A

    2016-10-01

    Novel fire regimes are an important cause and consequence of global environmental change that involve interactions among biotic, climatic, and human components of ecosystems. Plant flammability is key to these interactions, yet few studies directly measure flammability or consider how multiple species with different flammabilities interact to produce novel fire regimes. Deserts of the southwestern United States are an ideal system for exploring how novel fire regimes can emerge when fire-promoting species invade ecosystems comprised of species that did not evolve with fire. In these deserts, exotic annual grasses provide fuel continuity across landscapes that did not historically burn. These fires often ignite a keystone desert shrub, the fire-intolerant creosote bush, Larrea tridentata (DC.) Coville. Ignition of Larrea is likely catalyzed by fuels produced by native plants that grow beneath the shrubs. We hypothesize that invasive and native species exhibit distinct flammability characteristics that in combination determine spatial patterns of fire spread and intensity. We measured flammability metrics of Larrea, two invasive grasses, Schismus arabicus and Bromus madritensis, and two native plants, the sub-shrub Ambrosia dumosa and the annual herb Amsinckia menziesii. Results of laboratory experiments show that the grasses carry fire quickly (1.32 cm/s), but burn for short duration (0.5 min) at low temperatures. In contrast, native plants spread fire slowly (0.12 cm/s), but burn up to eight times longer (4 min) and produced hotter fires. Additional experiments on the ignition requirements of Larrea suggest that native plants burn with sufficient temperature and duration to ignite dead Larrea branches (time to ignition, 2 min; temperature at ignition 692°C). Once burning, these dead branches ignite living branches in the upper portions of the shrub. Our study provides support for a conceptual model in which exotic grasses are "spreaders" of fire and native

  11. Do I Belong? Factors Contributing to the Development of Social Belonging of Children Who Are Homeless in Southeastern United States Shelters: A Multi-Case Study

    Science.gov (United States)

    Ott, Corilyn Mae

    2012-01-01

    This qualitative multiple case study explored the factors that contribute to the development of social belonging in the classroom for children who are homeless age's five to seven. Previous empirical research has shown the importance of children who are homeless developing belonging in the classroom and other research has shown the negative…

  12. Integrated production of warm season grasses and agroforestry for biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Samson, R.; Omielan, J. [Resource Efficient Agricultural Production-Canada, Ste, Anne de Bellevue, Quebec (Canada); Girouard, P.; Henning, J. [McGill Univ., Ste. Anne de Bellevue, Quebec (Canada)

    1993-12-31

    Increased research on C{sub 3} and C{sub 4} perennial biomass crops is generating a significant amount of information on the potential of these crops to produce large quantities of low cost biomass. In many parts of North America it appears that both C{sub 3} and C{sub 4} species are limited by water availability particularly on marginal soils. In much of North America, rainfall is exceeded by evaporation. High transpiration rates by fast growing trees and rainfall interception by the canopy appear to indicate that this can further exacerbate the problem of water availability. C{sub 4} perennial grasses appear to have distinct advantages over C{sub 3} species planted in monoculture systems particularly on marginal soils. C{sub 4} grasses historically predominated over much of the land that is now available for biomass production because of their adaptation to low humidity environments and periods of low soil moisture. The planting of short rotation forestry (SRF) species in an energy agroforestry system is proposed as an alternative production strategy which could potentially alleviate many of the problems associated with SRF monocultures. Energy agroforestry would be complementary to both production of conventional farm crops and C{sub 4} perennial biomass crops because of beneficial microclimatic effects.

  13. Multiple photosynthetic transitions, polyploidy, and lateral gene transfer in the grass subtribe Neurachninae.

    Science.gov (United States)

    Christin, Pascal-Antoine; Wallace, Mark J; Clayton, Harmony; Edwards, Erika J; Furbank, Robert T; Hattersley, Paul W; Sage, Rowan F; Macfarlane, Terry D; Ludwig, Martha

    2012-10-01

    The Neurachninae is the only grass lineage known to contain C(3), C(4), and C(3)-C(4) intermediate species, and as such has been suggested as a model system for studies of photosynthetic pathway evolution in the Poaceae; however, a lack of a robust phylogenetic framework has hindered this possibility. In this study, plastid and nuclear markers were used to reconstruct evolutionary relationships among Neurachninae species. In addition, photosynthetic types were determined with carbon isotope ratios, and genome sizes with flow cytometry. A high frequency of autopolyploidy was found in the Neurachninae, including in Neurachne munroi F.Muell. and Paraneurachne muelleri S.T.Blake, which independently evolved C(4) photosynthesis. Phylogenetic analyses also showed that following their separate C(4) origins, these two taxa exchanged a gene encoding the C(4) form of phosphoenolpyruvate carboxylase. The C(3)-C(4) intermediate Neurachne minor S.T.Blake is phylogenetically distinct from the two C(4) lineages, indicating that intermediacy in this species evolved separately from transitional stages preceding C(4) origins. The Neurachninae shows a substantial capacity to evolve new photosynthetic pathways repeatedly. Enablers of these transitions might include anatomical pre-conditions in the C(3) ancestor, and frequent autopolyploidization. Transfer of key C(4) genetic elements between independently evolved C(4) taxa may have also facilitated a rapid adaptation of photosynthesis in these grasses that had to survive in the harsh climate appearing during the late Pliocene in Australia.

  14. Energy evaluation of fresh grass in the diets of lactating dairy cows

    NARCIS (Netherlands)

    Bruinenberg, M.H.; Zom, R.L.G.; Valk, H.

    2002-01-01

    The discrepancy between the estimated feeding value of fresh grass and the output per kg grass in terms of milk and maintenance was studied by evaluating 12 experiments with grass-fed dairy cows. The percentage grass in the diets varied between 40 and 90. Intake and milk production were recorded

  15. Transgenesis and genomics in molecular breeding of pasture grasses and legumes for forage quality and other traits

    International Nuclear Information System (INIS)

    Spangenberg, G.

    2005-01-01

    Significant advances in the establishment of the methodologies required for the molecular breeding of temperate forage grasses (Lolium and Festuca species) and legumes (Trifolium and Medicago species) are reviewed. Examples of current products and approaches for the application of these methodologies to forage grass and legume improvement are outlined. The plethora of new technologies and tools now available for high-throughput gene discovery and genome-wide expression analysis have opened up opportunities for innovative applications in the identification, functional characterization and use of genes of value in forage production systems and beyond. Selected examples of current work in pasture plant genomics, xenogenomics, symbiogenomics and micro-array-based molecular phenotyping are discussed. (author)

  16. Young Children in Day and Night Care: Negotiating and Constructing Belonging during Daily Arrivals

    Science.gov (United States)

    Salonen, Eija; Laakso, Marja-Leena; Sevón, Eija

    2016-01-01

    The paper aims at understanding the processes related to young children's belonging during daily arrivals at day and night care. Two aspects of a child's belonging are considered: membership and sense of belonging. Data were gathered by ethnographic observation of 8 children aged from 20 to 36 months in two Finnish day care centres offering day…

  17. Fostering School Belonging in Secondary Schools Using a Socio-Ecological Framework

    Science.gov (United States)

    Allen, Kelly-Ann; Vella-Brodrick, Dianne; Waters, Lea

    2016-01-01

    The benefits of belonging and feeling connected to school for adolescent mental health and wellbeing are well documented, but how belonging is fostered is less understood. The present article puts forward a new conceptual framework of school belonging based on Bronfenbrenner's (1979) sociological model of human development, using evidence from a…

  18. What Schools Need to Know about Fostering School Belonging: A Meta-Analysis

    Science.gov (United States)

    Allen, Kelly; Kern, Margaret L.; Vella-Brodrick, Dianne; Hattie, John; Waters, Lea

    2018-01-01

    Belonging is an essential aspect of psychological functioning. Schools offer unique opportunities to improve belonging for school-aged children. Research on school belonging, however, has been fragmented and diluted by inconsistency in the use of terminology. To resolve some of these inconsistencies, the current study uses meta-analysis of…

  19. Management of Florida Scrub for Threatened and Endangered Species

    Science.gov (United States)

    1998-12-01

    for Florida scrub: 1. The exotic species, cogon grass ( Imperata cylindrica), may become common in degraded scrubs. This is an aggressive, invasive...34Cogongrass, Imperata cylindrica (L.) Beauv.: A good grass gone bad!" Botany Circular No. 28, Florida Dept. Agric. & Consumer Services, Division of Plant...Industry, Gainesville, FL. Colvin, D.L., Gaffney, J., and Shilling, D. G. 1994. "Cogongrass ( Imperata cylindrica (L.) Beauv.) Biology, ecology and

  20. 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...... 3University of Aarhus, Dept. of Genetics and Biotechnology   Corresponding author: Ole Green Address & e-mail: Research Centre Foulum, Blichers Allé 20, 8830 Tjele. Ole.Green@agrsci.dk     Abstract   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...