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Sample records for afines poaceae pooideae

  1. 燕麦属系统学研究进展%Research Advances on Systematics of Avena (Pooideae, Poaceae)

    Institute of Scientific and Technical Information of China (English)

    刘青; 刘欢; 林磊

    2014-01-01

    Advances in taxonomy, systematics, and polyploid origins of Avena L. (Pooideae, Poaceae) were reviewed. The key issues in systematics studies of Avena included: the debate on phylogenetic position of Avena in the Avena group;the absence of conclusive evidence for the circumscription of Avena, especially for A. macrostachya Bal. ex Cass. & Dur.; the unresolved phylogenetic relationships of major lineages in Avena;the considerable controversy about the genomic origins of hexaploid cultivated oats (i.e., A. nuda L. and A. sativa L.);and the paucity of accurate estimation of divergence time of Avena. The controversies on the genomic origins of hexaploid cultivated oats are rooted in the absence of accurate understanding for the divergence of A, C, and D genomes. The comprehensive investigation of molecular phylogeny, cytogenetics, palaeogeology, and palaeoclimatology may provide compelling evidence for the polyploid origins and the divergence histories of Avena, and it is signiifcance for deeply utilizing the core germplasm resources of wild relatives of cereal crops.%对燕麦属(Avena L.)分类学、系统学、多倍体起源3个方面的研究进展进行了综述。燕麦属系统学研究存在的关键问题有:燕麦属的系统位置存在争议;燕麦属的范畴即大穗燕麦转隶归属问题缺少确证;燕麦属的系统发育关系尚未解决;六倍体栽培燕麦基因组起源备受争议;燕麦属分化时间尚未估测。六倍体栽培燕麦基因组起源争议的根源在于对A、C、D基因组间分化程度缺乏精准认识。总的来说,分子系统学、细胞遗传学、古地质学、古气候学的整合研究将为燕麦属多倍体起源和分化提供令人信服的新证据,对于深度利用谷类作物野生近缘种核心种质资源具有重要科学意义。

  2. A multi-locus analysis of phylogenetic relationships within grass subfamily Pooideae (Poaceae) inferred from sequences of nuclear single copy gene regions compared with plastid DNA.

    Science.gov (United States)

    Hochbach, Anne; Schneider, Julia; Röser, Martin

    2015-06-01

    To investigate phylogenetic relationships within the grass subfamily Pooideae we studied about 50 taxa covering all recognized tribes, using one plastid DNA (cpDNA) marker (matK gene-3'trnK exon) and for the first time four nuclear single copy gene loci. DNA sequence information from two parts of the nuclear genes topoisomerase 6 (Topo6) spanning the exons 8-13 and 17-19, the exons 9-13 encoding plastid acetyl-CoA-carboxylase (Acc1) and the partial exon 1 of phytochrome B (PhyB) were generated. Individual and nuclear combined data were evaluated using maximum parsimony, maximum likelihood and Bayesian methods. All of the phylogenetic results show Brachyelytrum and the tribe Nardeae as earliest diverging lineages within the subfamily. The 'core' Pooideae (Hordeeae and the Aveneae/Poeae tribe complex) are also strongly supported, as well as the monophyly of the tribes Brachypodieae, Meliceae and Stipeae (except PhyB). The beak grass tribe Diarrheneae and the tribe Duthieeae are not monophyletic in some of the analyses. However, the combined nuclear DNA (nDNA) tree yields the highest resolution and the best delimitation of the tribes, and provides the following evolutionary hypothesis for the tribes: Brachyelytrum, Nardeae, Duthieeae, Meliceae, Stipeae, Diarrheneae, Brachypodieae and the 'core' Pooideae. Within the individual datasets, the phylogenetic trees obtained from Topo6 exon 8-13 shows the most interesting results. The divergent positions of some clone sequences of Ampelodesmos mauritanicus and Trikeraia pappiformis, for instance, may indicate a hybrid origin of these stipoid taxa. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Distribution of the tryptophan pathway-derived defensive secondary metabolites gramine and benzoxazinones in Poaceae.

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    Kokubo, Yu; Nishizaka, Miho; Ube, Naoki; Yabuta, Yukinori; Tebayashi, Shin-Ichi; Ueno, Kotomi; Taketa, Shin; Ishihara, Atsushi

    2017-03-01

    The Poaceae is a large taxonomic group consisting of approximately 12,000 species and is classified into 12 subfamilies. Gramine and benzoxazinones (Bxs), which are biosynthesized from the tryptophan pathway, are well-known defensive secondary metabolites in the Poaceae. We analyzed the presence or absence of garamine and Bxs in 64 species in the Poaceae by LC-MS/MS. We found that Hordeum brachyantherum and Hakonechloa macra accumulated gramine, but the presence of gramine was limited to small groups of species. We also detected Bxs in four species in the Pooideae and six species in the Panicoideae. In particular, four species in the Paniceae tribe in Panicoideae accumulaed Bxs, indicating that this tribe is a center of the Bx distribution. Bxs were absent in the subfamilies other than Pooideae and Panicoideae. These findings provide an overview of biased distribution of gramine and Bxs in Poaceae species.

  4. Are diversification rates and chromosome evolution in the temperate grasses (Pooideae) associated with major environmental changes in the Oligocene-Miocene?

    Science.gov (United States)

    Pimentel, Manuel; Escudero, Marcial; Sahuquillo, Elvira; Minaya, Miguel Ángel; Catalán, Pilar

    2017-01-01

    The Pooideae are a highly diverse C3 grass subfamily that includes some of the most economically important crops, nested within the highly speciose core-pooid clade. Here, we build and explore the phylogeny of the Pooideae within a temporal framework, assessing its patterns of diversification and its chromosomal evolutionary changes in the light of past environmental transformations. We sequenced five plastid DNA loci, two coding (ndhF, matk) and three non-coding (trnH-psbA, trnT-L and trnL-F), in 163 Poaceae taxa, including representatives for all subfamilies of the grasses and all but four ingroup Pooideae tribes. Parsimony and Bayesian phylogenetic analyses were conducted and divergence times were inferred in BEAST using a relaxed molecular clock. Diversification rates were assessed using the MEDUSA approach, and chromosome evolution was analyzed using the chromEvol software. Diversification of the Pooideae started in the Late-Eocene and was especially intense during the Oligocene-Miocene. The background diversification rate increased significantly at the time of the origin of the Poodae + Triticodae clade. This shift in diversification occurred in a context of falling temperatures that potentially increased ecological opportunities for grasses adapted to open areas around the world. The base haploid chromosome number n = 7 has remained stable throughout the phylogenetic history of the core pooids and we found no link between chromosome transitions and major diversification events in the Pooideae.

  5. Late Cretaceous origin of the rice tribe provides evidence for early diversification in Poaceae.

    Science.gov (United States)

    Prasad, V; Strömberg, C A E; Leaché, A D; Samant, B; Patnaik, R; Tang, L; Mohabey, D M; Ge, S; Sahni, A

    2011-09-20

    Rice and its relatives are a focal point in agricultural and evolutionary science, but a paucity of fossils has obscured their deep-time history. Previously described cuticles with silica bodies (phytoliths) from the Late Cretaceous period (67-65 Ma) of India indicate that, by the latest Cretaceous, the grass family (Poaceae) consisted of members of the modern subclades PACMAD (Panicoideae-Aristidoideae-Chloridoideae-Micrairoideae-Arundinoideae-Danthonioideae) and BEP (Bambusoideae-Ehrhartoideae-Pooideae), including a taxon with proposed affinities to Ehrhartoideae. Here we describe additional fossils and show that, based on phylogenetic analyses that combine molecular genetic data and epidermal and phytolith features across Poaceae, these can be assigned to the rice tribe, Oryzeae, of grass subfamily Ehrhartoideae. The new Oryzeae fossils suggest substantial diversification within Ehrhartoideae by the Late Cretaceous, pushing back the time of origin of Poaceae as a whole. These results, therefore, necessitate a re-evaluation of current models for grass evolution and palaeobiogeography.

  6. Dated historical biogeography of the temperate Loliinae (Poaceae, Pooideae) grasses in the northern and southern hemispheres.

    Science.gov (United States)

    Inda, Luis A; Segarra-Moragues, José Gabriel; Müller, Jochen; Peterson, Paul M; Catalán, Pilar

    2008-03-01

    Divergence times and biogeographical analyses have been conducted within the Loliinae, one of the largest subtribes of temperate grasses. New sequence data from representatives of the almost unexplored New World, New Zealand, and Eastern Asian centres were added to those of the panMediterranean region and used to reconstruct the phylogeny of the group and to calculate the times of lineage-splitting using Bayesian approaches. The traditional separation between broad-leaved and fine-leaved Festuca species was still maintained, though several new broad-leaved lineages fell within the fine-leaved clade or were placed in an unsupported intermediate position. A strong biogeographical signal was detected for several Asian-American, American, Neozeylandic, and Macaronesian clades with different affinities to both the broad and the fine-leaved Festuca. Bayesian estimates of divergence and dispersal-vicariance analyses indicate that the broad-leaved and fine-leaved Loliinae likely originated in the Miocene (13My) in the panMediterranean-SW Asian region and then expanded towards C and E Asia from where they colonized the New World. Further expansions in America (10-3.8My) showed a predominant migratory route from North to South (N Americathe AndesPatagonia). This late Tertiary scenario of successive colonizations and secondary polyploid radiations in the southern hemisphere from the northern hemisphere was accompanied by occasional transcontinental long-distance dispersal events between South America and New Zealand. Multiple Pliocene dispersal events (3.6-2.5My) from the near SW European and NW African continents gave rise to the Macaronesian Loliinae flora, while a more recent Pleistocene origin (2-1My) is hypothesized for the high polyploid lineages that successfully colonized newly deglaciated areas in both hemispheres.

  7. SINOPSIS DE LAS ESPECIES AUSTRO-AMERICANAS DEL GÉNERO NASSELLA (POACEAE, POOIDEAE, STIPEAE

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    Ana M. Cialdella

    2013-01-01

    Full Text Available Nassella es un género americano que, de acuerdo a su actual circunscripción, incluye unas 116 especies, distribuidas desde Canadá hasta Argentina y Chile. Se caracteriza por sus antecios con la lema notablemente convoluta, con corona apical conspicua o inconspicua y la pálea menor que la lema; asimismo, la lema presenta un patrón epidérmico distintivo. El objetivo de este trabajo es realizar una sinopsis de las 99 especies de Nassella que crecen en la región austral de América del Sur, comprendiendo la Argentina, Bolivia, sur de Brasil, Chile, Paraguay y Uruguay. Se proporciona una clave para la identificación de las especies, sobre la base principalmente de caracteres del antecio. Para cada especie se brinda la sinonimia actualizada, distribución geográfica, datos fenológicos, observaciones e ilustraciones. Se acepta a Nassella barbinodis y Nassella linearifolia es un nuevo sinónimo de Nassella caespitosa. Se designan lectotipos para los siguientes taxones: Danthonia nardoides, Piptochaetium collinum, P. gibbum, P. laevissimum, Stipa arechavaletae, S. barbinodis, S. breviculmis, S. calchaquia, S. carettei, S. clarazii var. bulbosa, S. curicoana, S. debilis var. papillosa, S. duriuscula, S. hispida, S. hyalina, S. julietii, S. longiglumis, S. macrathera, S. manicata var. media, S. mendocina, S. pratensis, S. pseudopampagrandensis, S. rupestris, S. tenuis, S. trachysperma, S. trichocaulos y S. uspallatensis. Se designa un neotipo para S. filiculmis.

  8. Estructura de las inflorescencias en especies de Melica (Meliceae-Pooideae-Poaceae

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    Mariel G. Perreta

    2004-01-01

    Full Text Available Sinflorescencias de 17 especies del género Melica presentes en Argentina han sido estudiadas desde el punto de vista tipológico. Las inflorescencias son politélicas, presentan florescencia principal, no sufrieron procesos de homogeneización y/o truncamiento y muestran un patrón similar de desarrollo de la zona paracladial. Las principales variaciones se observan en el nivel del número de paracladios primarios, grado de ramificación de los paracladios primarios, reducción gradual o brusca de la longitud de los entrenudos del eje principal, disposición adpresa o divergente de los paracladios. El grado de ramificación del antotagma se amplifica por el desarrollo de paracladios en posición profilar. La mayoría de las especies (excepto M. sarmentosa carecen de paracladios largos con trofotagma

  9. Las Poáceas del Parque Nacional Yanachaga-Chemillén (Oxapampa, Perú. Parte II: Pooideae, Centothecoideae, Arundinoideae, Chloridoideae y Panicoideae

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    María I. La-Torre

    2013-06-01

    Full Text Available Se presenta la segunda parte de un estudio taxonómico de la Familia Poaceae del Parque Nacional Yanachaga-Chemillén y zonas aledañas (Oxapampa, Pasco, Perú. Se presentan 63 especies de Poáceas de las subfamilias Pooideae, Centothecoideae, Arundinoideae, Chloridoideae y Panicoideae, las cuales están incluidas en 37 géneros y 12 tribus. Se incluye una breve descripción de los géneros. Se ha elaborado claves para diferenciar los géneros y especies. Para cada especie se indica su ecología, distribución y el material estudiado.

  10. Evidence for adaptive evolution of low-temperature stress response genes in a Pooideae grass ancestor

    DEFF Research Database (Denmark)

    Vigeland, Magnus D; Spannagl, Manuel; Asp, Torben

    2013-01-01

    evolution of LTI pathway genes was important for Pooideae evolution. Substitution rates and signatures of positive selection were analyzed using 4330 gene trees including three warm climate-adapted species (maize (Zea mays), sorghum (Sorghum bicolor), and rice (Oryza sativa)) and five temperate Pooideae...

  11. Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses1[OPEN

    Science.gov (United States)

    McKeown, Meghan; Fjellheim, Siri

    2016-01-01

    The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones. Grasses of subfamily Pooideae, including several important crops, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and oats (Avena sativa), predominate in the northern temperate zone, and it is hypothesized that their radiation was facilitated by the early evolution of vernalization responsiveness. Predictions of this early origin hypothesis are that a response to vernalization is widespread within the subfamily and that the genetic basis of this trait is conserved. To test these predictions, we determined and reconstructed vernalization responsiveness across Pooideae and compared expression of wheat vernalization gene orthologs VERNALIZATION1 (VRN1) and VRN3 in phylogenetically representative taxa under cold and control conditions. Our results demonstrate that vernalization responsive Pooideae species are widespread, suggesting that this trait evolved early in the lineage and that at least part of the vernalization gene network is conserved throughout the subfamily. These results are consistent with the hypothesis that the evolution of vernalization responsiveness was important for the initial transition of Pooideae out of the tropics and into the temperate zone. PMID:27474116

  12. Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses.

    Science.gov (United States)

    McKeown, Meghan; Schubert, Marian; Marcussen, Thomas; Fjellheim, Siri; Preston, Jill C

    2016-09-01

    The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones. Grasses of subfamily Pooideae, including several important crops, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and oats (Avena sativa), predominate in the northern temperate zone, and it is hypothesized that their radiation was facilitated by the early evolution of vernalization responsiveness. Predictions of this early origin hypothesis are that a response to vernalization is widespread within the subfamily and that the genetic basis of this trait is conserved. To test these predictions, we determined and reconstructed vernalization responsiveness across Pooideae and compared expression of wheat vernalization gene orthologs VERNALIZATION1 (VRN1) and VRN3 in phylogenetically representative taxa under cold and control conditions. Our results demonstrate that vernalization responsive Pooideae species are widespread, suggesting that this trait evolved early in the lineage and that at least part of the vernalization gene network is conserved throughout the subfamily. These results are consistent with the hypothesis that the evolution of vernalization responsiveness was important for the initial transition of Pooideae out of the tropics and into the temperate zone.

  13. Comparative transcriptomics of three Poaceae species reveals patterns of gene expression evolution.

    Science.gov (United States)

    Davidson, Rebecca M; Gowda, Malali; Moghe, Gaurav; Lin, Haining; Vaillancourt, Brieanne; Shiu, Shin-Han; Jiang, Ning; Robin Buell, C

    2012-08-01

    The Poaceae family, also known as the grasses, includes agronomically important cereal crops such as rice, maize, sorghum, and wheat. Previous comparative studies have shown that much of the gene content is shared among the grasses; however, functional conservation of orthologous genes has yet to be explored. To gain an understanding of the genome-wide patterns of evolution of gene expression across reproductive tissues, we employed a sequence-based approach to compare analogous transcriptomes in species representing three Poaceae subgroups including the Pooideae (Brachypodium distachyon), the Panicoideae (sorghum), and the Ehrhartoideae (rice). Our transcriptome analyses reveal that only a fraction of orthologous genes exhibit conserved expression patterns. A high proportion of conserved orthologs include genes that are upregulated in physiologically similar tissues such as leaves, anther, pistil, and embryo, while orthologs that are highly expressed in seeds show the most diverged expression patterns. More generally, we show that evolution of gene expression profiles and coding sequences in the grasses may be linked. Genes that are highly and broadly expressed tend to be conserved at the coding sequence level while genes with narrow expression patterns show accelerated rates of sequence evolution. We further show that orthologs in syntenic genomic blocks are more likely to share correlated expression patterns compared with non-syntenic orthologs. These findings are important for agricultural improvement because sequence information is transferred from model species, such as Brachypodium, rice, and sorghum to crop plants without sequenced genomes. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  14. Early inflorescence development in the grasses (Poaceae).

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    Kellogg, Elizabeth A; Camara, Paulo E A S; Rudall, Paula J; Ladd, Philip; Malcomber, Simon T; Whipple, Clinton J; Doust, Andrew N

    2013-01-01

    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 180°, 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.

  15. Competição entre afinal e enfim

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    Ivanete Mileski

    2015-07-01

    Full Text Available O presente estudo concentra-se no uso dos marcadores discursivos afinal e enfim a partir de dados do Corpus do Português Davies-Ferreira. Primeiramente, faz-se uma breve apresentação sobre marcadores discursivos. Em um segundo momento, busca-se elencar os usos mais comuns de cada um dos marcadores em foco no estudo para, posteriormente, abordar seu desenvolvimento diacrônico. Segue-se a análise dos dados, cujo intuito é comparar o número de usos de afinal e enfim com o valor justificativo, uso que os dois marcadores partilham.A partir da análise, foi possível verificar, entre outros resultados, que: a a frequência de ambos os marcadores diminuiu do século 19 para o século 20; b o marcador enfim com valor justificativo, mais frequente que afinal com o mesmo valor no século 19, foi superado em frequência por afinal no século 20. A maior frequência de afinal justificativo em relação a enfim, no século 20, está de acordo com o Princípio de Contraste, postulado por Clark(1980.

  16. High-Throughput Sequencing of Six Bamboo Chloroplast Genomes: Phylogenetic Implications for Temperate Woody Bamboos (Poaceae: Bambusoideae)

    Science.gov (United States)

    Li, De-Zhu

    2011-01-01

    Background Bambusoideae is the only subfamily that contains woody members in the grass family, Poaceae. In phylogenetic analyses, Bambusoideae, Pooideae and Ehrhartoideae formed the BEP clade, yet the internal relationships of this clade are controversial. The distinctive life history (infrequent flowering and predominance of asexual reproduction) of woody bamboos makes them an interesting but taxonomically difficult group. Phylogenetic analyses based on large DNA fragments could only provide a moderate resolution of woody bamboo relationships, although a robust phylogenetic tree is needed to elucidate their evolutionary history. Phylogenomics is an alternative choice for resolving difficult phylogenies. Methodology/Principal Findings Here we present the complete nucleotide sequences of six woody bamboo chloroplast (cp) genomes using Illumina sequencing. These genomes are similar to those of other grasses and rather conservative in evolution. We constructed a phylogeny of Poaceae from 24 complete cp genomes including 21 grass species. Within the BEP clade, we found strong support for a sister relationship between Bambusoideae and Pooideae. In a substantial improvement over prior studies, all six nodes within Bambusoideae were supported with ≥0.95 posterior probability from Bayesian inference and 5/6 nodes resolved with 100% bootstrap support in maximum parsimony and maximum likelihood analyses. We found that repeats in the cp genome could provide phylogenetic information, while caution is needed when using indels in phylogenetic analyses based on few selected genes. We also identified relatively rapidly evolving cp genome regions that have the potential to be used for further phylogenetic study in Bambusoideae. Conclusions/Significance The cp genome of Bambusoideae evolved slowly, and phylogenomics based on whole cp genome could be used to resolve major relationships within the subfamily. The difficulty in resolving the diversification among three clades of

  17. High-throughput sequencing of six bamboo chloroplast genomes: phylogenetic implications for temperate woody bamboos (Poaceae: Bambusoideae.

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    Yun-Jie Zhang

    Full Text Available BACKGROUND: Bambusoideae is the only subfamily that contains woody members in the grass family, Poaceae. In phylogenetic analyses, Bambusoideae, Pooideae and Ehrhartoideae formed the BEP clade, yet the internal relationships of this clade are controversial. The distinctive life history (infrequent flowering and predominance of asexual reproduction of woody bamboos makes them an interesting but taxonomically difficult group. Phylogenetic analyses based on large DNA fragments could only provide a moderate resolution of woody bamboo relationships, although a robust phylogenetic tree is needed to elucidate their evolutionary history. Phylogenomics is an alternative choice for resolving difficult phylogenies. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the complete nucleotide sequences of six woody bamboo chloroplast (cp genomes using Illumina sequencing. These genomes are similar to those of other grasses and rather conservative in evolution. We constructed a phylogeny of Poaceae from 24 complete cp genomes including 21 grass species. Within the BEP clade, we found strong support for a sister relationship between Bambusoideae and Pooideae. In a substantial improvement over prior studies, all six nodes within Bambusoideae were supported with ≥0.95 posterior probability from Bayesian inference and 5/6 nodes resolved with 100% bootstrap support in maximum parsimony and maximum likelihood analyses. We found that repeats in the cp genome could provide phylogenetic information, while caution is needed when using indels in phylogenetic analyses based on few selected genes. We also identified relatively rapidly evolving cp genome regions that have the potential to be used for further phylogenetic study in Bambusoideae. CONCLUSIONS/SIGNIFICANCE: The cp genome of Bambusoideae evolved slowly, and phylogenomics based on whole cp genome could be used to resolve major relationships within the subfamily. The difficulty in resolving the diversification among

  18. CATÁLOGO DE LA FAMILIA POACEAE EN COLOMBIA

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    Diego Giraldo-Cañas

    2011-01-01

    distribución asociada con la altura sobre el nivel del mar y/o con la precipitación; así tenemos que las Panicoideae son más diversas en las tierras bajas y húmedas y en áreas abiertas de zonas subandinas, las Pooideae en las tierras alto-andinas (páramos, las Chloridoideae en las áreas secas, los bambúes herbáceos en la Región Amazónica y los bambúes leñosos en la Región Andina. Las Poaceae constituyen la sexta familia más rica en la flora de Colombia, después de las Orchidaceae, las Asteraceae, las Rubiaceae, las Fabaceae y las Melastomataceae.

  19. IDENTIFIKASI TUMBUHAN SUKU POACEAE SEBAGAI SUPLEMEN MATAKULIAH KEANEKARAGAMAN TUMBUHAN

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    Desy Yanuarita Wulandari; Murni Sapta Sari; Susriyati Mahanal

    2017-01-01

    Poaceae known as plants used as food ingredients in Indonesian. One area thas has high level diversity of plants Poaceae is Tahura R. Soerjo. Morphological characterization Poaceae in that region are still rare. The Goal for this research are to identify Poaceae tribes, and make photography Poaceae data that can be used as a supplement on Diversity of Plants course. This study included descriptive exploratory study with free cruising method. The species Poaceae has identified are Bambusa mult...

  20. Early inflorescence development in the grasses (Poaceae

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    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. Phylogenetic study of Oryzoideae species and related taxa of the Poaceae based on atpB-rbcL and ndhF DNA sequences.

    Science.gov (United States)

    Zeng, Xu; Yuan, Zhengrong; Tong, Xin; Li, Qiushi; Gao, Weiwei; Qin, Minjian; Liu, Zhihua

    2012-05-01

    Oryzoideae (Poaceae) plants have economic and ecological value. However, the phylogenetic position of some plants is not clear, such as Hygroryza aristata (Retz.) Nees. and Porteresia coarctata (Roxb.) Tateoka (syn. Oryza coarctata). Comprehensive molecular phylogenetic studies have been carried out on many genera in the Poaceae. The different DNA sequences, including nuclear and chloroplast sequences, had been extensively employed to determine relationships at both higher and lower taxonomic levels in the Poaceae. Chloroplast DNA ndhF gene and atpB-rbcL spacer were used to construct phylogenetic trees and estimate the divergence time of Oryzoideae, Bambusoideae, Panicoideae, Pooideae and so on. Complete sequences of atpB-rbcL and ndhF were generated for 17 species representing six species of the Oryzoideae and related subfamilies. Nicotiana tabacum L. was the outgroup species. The two DNA datasets were analyzed, using Maximum Parsimony and Bayesian analysis methods. The molecular phylogeny revealed that H. aristata (Retz.) Nees was the sister to Chikusichloa aquatica Koidz. Moreover, P. coarctata (Roxb.) Tateoka was in the genus Oryza. Furthermore, the result of evolution analysis, which based on the ndhF marker, indicated that the time of origin of Oryzoideae might be 31 million years ago.

  2. Teologi Mustad’afin di Indonesia: Kajian atas Teologi Muhammadiyah

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    Sokhi Huda

    2015-02-01

    Full Text Available Mustad’afin Theology in Indonesia is the new face of  al-Ma’un theology initiated by the Ahmad Dahlan. It eventually accumulates with more extensive issues and involves partnerships with other parties in order to achieve its praxis strategy. The basic assumption of  this theology is that the practice of  worship must be directly related to social concerns, with a foundation of monotheism that manifests itself  into the realm of  praxis. This finally leads to the key words of “social unity” and “social rituals” which are then developed in the context of contemporary nationhood and statehood in Indonesia. Moreover, its epistemology primarily comes from: (1 Wahhabi-Salafi ideology of  Rashid Rida, (2 the idea of    education reform of  Muhammad ‘Abduh, and (3 theology of al-Ma’un of Ahmad  Dahlan. These three basic epistemologies are equipped with a significant adaptation to seven factors, in order to be accepted as a theology of  liberators movement in Indonesia. The performance of  Mustad’afin theology is a theology that does social defense for the following conditions: (1 oppression of faith, (2 retardation, (3 suffering of economic and social status, (4 moral suffering, and (5 the threat of theologies and the existence of Indonesia. Finally, it implies the necessity of  Mustad’afin Islamic Jurisprudence to regulate the conduct of  worship and social community. Furthermore, the exclusive part of  Wahhabi-Salafi Islamic jurisprudence is no longer posed.

  3. Manual Control de calidad en productos textiles y afines

    OpenAIRE

    Alonso Felipe, Jose Vicente

    2015-01-01

    El campo de los materiales textiles y afines no suele estar incluido dentro de la disciplina de Conocimiento de materiales o en ocasiones suele estar mínimamente contemplado dentro del área de materiales plásticos y polímeros; por lo cual en general suele ser muy desconocido en la formación de ingenieros y técnicos. Históricamente en las escuelas de ingenieros industriales se encontraba la especialización en industrias textiles, aunque con posterioridad pasó a formar una carrera propia como t...

  4. Poaceae: an overview with reference to Brazil

    OpenAIRE

    Longhi-Wagner,Hilda Maria

    2012-01-01

    A summary of the classification of Poaceae into subfamilies according to different proposals is provided, as well as data on morphology and chorology of grasses, especially those that occur in Brazil.

  5. Sixty million years in evolution of soft grain trait in grasses: emergence of the softness locus in the common ancestor of Pooideae and Ehrhartoideae, after their divergence from Panicoideae.

    Science.gov (United States)

    Charles, Mathieu; Tang, Haibao; Belcram, Harry; Paterson, Andrew; Gornicki, Piotr; Chalhoub, Boulos

    2009-07-01

    Together maize, Sorghum, rice, and wheat grass (Poaceae) species are the most important cereal crops in the world and exhibit different "grain endosperm texture." This trait has been studied extensively in wheat because of its pivotal role in determining quality of products obtained from wheat grain. Grain softness protein-1 and Puroindolines A and B (grain storage proteins), encoded by Ha-like genes: Gsp-1, Pina, and Pinb, of the Hardness (Ha) locus, are the main determinants of the grain softness/hardness trait in wheat. The origin and evolution of grain endosperm texture in grasses was addressed by comparing genomic sequences of the Ha orthologous region of wheat, Brachypodium, rice, and Sorghum. Results show that the Ha-like genes are present in wheat and Brachypodium but are absent from Sorghum bicolor. A truncated remnant of an Ha-like gene is present in rice. Synteny analysis of the genomes of these grass species shows that only one of the paralogous Ha regions, created 70 My by whole-genome duplication, contained Ha-like genes. The comparative genome analysis and evolutionary comparison with genes encoding grain reserve proteins of grasses suggest that an ancestral Ha-like gene emerged, as a new member of the prolamin gene family, in a common ancestor of the Pooideae (Triticeae and Brachypoidieae tribes) and Ehrhartoideae (rice), between 60 and 50 My, after their divergence from Panicoideae (Sorghum). It was subsequently lost in Ehrhartoideae. Recurring duplications, deletions, and/or truncations occurred independently and appear to characterize Ha-like gene evolution in the grass species. The Ha-like genes gained a new function in Triticeae, such as wheat, underlying the soft grain phenotype. Loss of these genes in some wheat species leads, in turn, to hard endosperm seeds.

  6. Allergen Microarray Indicates Pooideae Sensitization in Brazilian Grass Pollen Allergic Patients.

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    Priscila Ferreira de Sousa Moreira

    Full Text Available Grass pollen, in particular from Lolium multiflorum is a major allergen source in temperate climate zones of Southern Brazil. The IgE sensitization profile of Brazilian grass pollen allergic patients to individual allergen molecules has not been analyzed yet.To analyze the IgE sensitization profile of a Brazilian grass pollen allergic population using individual allergen molecules.We analyzed sera from 78 grass pollen allergic patients for the presence of IgE antibodies specific for 103 purified micro-arrayed natural and recombinant allergens by chip technology. IgE-ELISA inhibition experiments with Lolium multiflorum, Phleum pratense extracts and a recombinant fusion protein consisting of Phl p 1, Phl p 2, Phl p 5 and Phl p 6 were performed to investigate cross-reactivities.Within the Brazilian grass pollen allergic patients, the most frequently recognized allergens were Phl p 1 (95%, Phl p 5 (82%, Phl p 2 (76% followed by Phl p 4 (64%, Phl p 6 (45%, Phl p 11 (18% and Phl p 12 (18%. Most patients were sensitized only to grass pollen allergens but not to allergens from other sources. A high degree of IgE cross-reactivity between Phleum pratense, Lolium multiflorum and the recombinant timothy grass fusion protein was found.Component-resolved analysis of sera from Brazilian grass pollen allergic patients reveals an IgE recognition profile compatible with a typical Pooideae sensitization. The high degree of cross-reactivity between Phleum pratense and Lolium multiflorum allergens suggests that diagnosis and immunotherapy can be achieved with timothy grass pollen allergens in the studied population.

  7. diversity in the grasses (Poaceae

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    Elizabeth A. Kellogg

    2006-01-01

    Full Text Available La familia de las Gramíneas (Poaceae es bien conocida desde el punto de vista taxonómico, con más de 10.000 especies descriptas, caracterizadas y clasificadas de acuerdo con una variedad de caracteres morfológicos, en particular de la inflorescencia y de la espiguilla, como también por una gran cantidad de caracteres micromorfológicos y moleculares. Información abundante sobre esta familia es accesible electrónicamente. Las filogenias disponibles han identificado 12 linajes principales clasificados como subfamilias, dentro de cada una de ellas, y en particular dentro de la subfamilia Panicoideae, la filogenia se está revelando con creciente claridad. Los estudios de desarrollo se enfocan en la actividad y el destino de los meristemas de toda la planta, e ilustran cómo se origina la morfología adulta. Los análisis de loci de caracteres cuantitativos (QTL verifican que algunos caracteres taxonómicos son controlados por genes diferentes, apoyando el uso de estos caracteres en la taxonomía. Los estudios de expresión génica identifican varios genes, entre ellos LEAFY HULL STERILE1, RAMOSA1, y TEOSINTE BRANCHED1, que pueden haber contribuido a la diversificación de las gramíneas.

  8. Quantifiable differences between phytolith assemblages detected at species level: analysis of the leaves of nine Poa species (Poaceae

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    Zsuzsa Lisztes-Szabó

    2015-10-01

    Full Text Available The taxonomic value of phytolith assemblages and their degree of variability within different species of the same genus is still an undervalued issue in the botanical range of phytolith studies. However the understanding of grass phytolith variance and its implications to plant systematics is doubtless. In the present study phytoliths of the lateral shoots (leaves of nine, globally distributed Poa species (PooideaePoaceae are described. Phytoliths were recovered from Poa specimens by the dry ashing technique. Altogether 6223 disarticulated phytoliths were counted (approximately 500–700 phytoliths per species in 54 plant samples, which cover six shoots of nine species. Not only the relative frequency of each morphotype was calculated, but measurements were conducted to determine the biogenic silica content of Poa lateral shoots. A phytolith reference collection for the nine selected species of a worldwide importance was also compiled. The description of the most significant phytolith morphotypes and their taxonomic relationships are given here. Results suggest that the biogenic silica content of the Poa lateral shoots was determined to be relatively high within all nine species. Phytolith assemblage data was subjected to multivariate statistical analyses (e.g., CA and PCA in order to find differences and similarities among the nine Poa species. Results show that the two closely related Poa of the P. pratensis species group, namely the P. pratensis and P. angustifolia, only slightly differ from the other Poa species if we consider their rondel-trapeziform short cells (SC phytolith frequencies.

  9. Danzantes y afines. La Danza de los Cascabeleros de Alosno

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    Jiménez de Madariaga, Celeste

    2006-06-01

    Full Text Available Many traditional dances of a religious character are dedicated to certain devotions and concern local images of virgins and patron saints that are identified with their community. They are ritual, festive dances, generally serving as dominant symbolic elements, indispensable for the feast. The Dance of the Cascabeleros of Alosno is an extraordinary model of such a dance, the expression and interpretation of which is connected with the process of social identification. This dance establishes relations of afinity based on gender and on the common action of dancing by the community as a whole. The author draws from this case to argue for the importance of analyzing dances as a way of communicating messages about the collective imaginary as well as the social and cultural context in which they are performed.

    Muchas danzas tradicionales de carácter religioso se dedican a determinadas devociones, imágenes de vírgenes y santos patronos muy localizadas e identificadas con su comunidad. Son danzas festivo-rituales que generalmente actúan como elementos simbólicos dominantes e imprescindibles para la realización de la fiesta. La Danza de los Cascabeleros de Alosno es un extraordinario modelo de danza festivo ritual, cuya expresión e interpretación se vincula a los procesos de identificación social. Esta danza establece relaciones de afinidad basadas en el género y en la común acción de danzar que implican a toda la comunidad en conjunto. A partir de este ejemplo, la autora demuestra la importancia de analizar las danzas como manifestaciones que comunican mensajes sobre el imaginario colectivo y el contexto social y cultural donde se representan.

  10. Phylogenomic analyses of nuclear genes reveal the evolutionary relationships within the BEP clade and the evidence of positive selection in Poaceae.

    Science.gov (United States)

    Zhao, Lei; Zhang, Ning; Ma, Peng-Fei; Liu, Qi; Li, De-Zhu; Guo, Zhen-Hua

    2013-01-01

    BEP clade of the grass family (Poaceae) is composed of three subfamilies, i.e. Bambusoideae, Ehrhartoideae, and Pooideae. Controversies on the phylogenetic relationships among three subfamilies still persist in spite of great efforts. However, previous evidence was mainly provided from plastid genes with only a few nuclear genes utilized. Given different evolutionary histories recorded by plastid and nuclear genes, it is indispensable to uncover their relationships based on nuclear genes. Here, eleven species with whole-sequenced genome and six species with transcriptomic data were included in this study. A total of 121 one-to-one orthologous groups (OGs) were identified and phylogenetic trees were reconstructed by different tree-building methods. Genes which might have undergone positive selection and played important roles in adaptive evolution were also investigated from 314 and 173 one-to-one OGs in two bamboo species and 14 grass species, respectively. Our results support the ((B, P) E) topology with high supporting values. Besides, our findings also indicate that 24 and nine orthologs with statistically significant evidence of positive selection are mainly involved in abiotic and biotic stress response, reproduction and development, plant metabolism and enzyme etc. from two bamboo species and 14 grass species, respectively. In summary, this study demonstrates the power of phylogenomic approach to shed lights on the evolutionary relationships within the BEP clade, and offers valuable insights into adaptive evolution of the grass family.

  11. Phylogenomic analyses of nuclear genes reveal the evolutionary relationships within the BEP clade and the evidence of positive selection in Poaceae.

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    Full Text Available BEP clade of the grass family (Poaceae is composed of three subfamilies, i.e. Bambusoideae, Ehrhartoideae, and Pooideae. Controversies on the phylogenetic relationships among three subfamilies still persist in spite of great efforts. However, previous evidence was mainly provided from plastid genes with only a few nuclear genes utilized. Given different evolutionary histories recorded by plastid and nuclear genes, it is indispensable to uncover their relationships based on nuclear genes. Here, eleven species with whole-sequenced genome and six species with transcriptomic data were included in this study. A total of 121 one-to-one orthologous groups (OGs were identified and phylogenetic trees were reconstructed by different tree-building methods. Genes which might have undergone positive selection and played important roles in adaptive evolution were also investigated from 314 and 173 one-to-one OGs in two bamboo species and 14 grass species, respectively. Our results support the ((B, P E topology with high supporting values. Besides, our findings also indicate that 24 and nine orthologs with statistically significant evidence of positive selection are mainly involved in abiotic and biotic stress response, reproduction and development, plant metabolism and enzyme etc. from two bamboo species and 14 grass species, respectively. In summary, this study demonstrates the power of phylogenomic approach to shed lights on the evolutionary relationships within the BEP clade, and offers valuable insights into adaptive evolution of the grass family.

  12. LA TRADUCCIÓN EN LA ENSEÑANZA DE LAS LENGUAS AFINES

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    Lucia Toppino

    2012-12-01

    Full Text Available El siguiente artículo quiere ser una propuesta para revalorar la utilización de la traducción en la enseñanza de las lenguas extranjeras, sobretodo en el caso de lenguas afines como italiano y español.

  13. Synopsis of Leymus Hochst. (Triticeae: Poaceae)

    Institute of Scientific and Technical Information of China (English)

    Chi YEN; jun-Liang YANG; Bernard R. BAUM

    2009-01-01

    Leymus is a genus in the Triticeae tribe, Poaceae. The taxa of this genus are allopolyploid species which possess the Ns and Xm genomes. According to cytological, cytogenetic and molecular genetic analyses, some species of Hystrix and Elymus ought to be transferred to this genus. A world revision of the genus Leymus is needed. In this paper we summarize experimental results, provide a key to sections, species and varieties, and list all the taxa we recognize in Leymus with their synonyms. This synopsis is a new taxonomic system to be used for the revision of Leymus.

  14. Inside the CBF locus in Poaceae.

    Science.gov (United States)

    Tondelli, Alessandro; Francia, Enrico; Barabaschi, Delfina; Pasquariello, Marianna; Pecchioni, Nicola

    2011-01-01

    Several molecular evidences have been gathered in Poaceae that point out a central role of the CBF/DREB1 transcription factors in the signal transduction pathways leading to low-temperature tolerance, although to a quite different extent between crops originating from either temperate or tropical climates. A common feature of the CBF/DREB1 genes in Poaceae is their structural organization at the genome level in clusters of tandemly duplicated genes. In temperate cereals such as barley and wheat, expansion of specific multigene phylogenetic clades of CBFs that map at the Frost Resistance-2 locus has been exclusively observed. In addition, copy number variants of CBF genes between frost resistant and frost sensitive genotypes raise the question if multiple copies of the CBF/DREB1s are required to ensure freezing tolerance. On the other hand, in crops of tropical origin such as rice and maize, a smaller or less-responsive CBF regulon may have evolved, and different mechanisms might determine chilling tolerance. In this review, recent advances on the organization and diversity at the CBF cluster locus in the grasses are provided and discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Linealización entrada/salida de sistemas no lineales afines utilizando un filtro

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    Alberto Delgado

    2011-02-01

    Full Text Available La linealización Entrada/Salida (E/S, dentro del marco teórico del control geométrico, es una técnica madura para sistemas no lineales afines. Esta técnica cancela los términos no lineales de la planta, usando una retroalimentación de estado no lineal, y produce una dinámica E/S lineal para la planta. En este artículo se muestra que un filtro D(s puede utilizarse para Iinealizar sistemas no lineales afines en lugar de aplicar una retroalimentación de estado no lineal que requiere conocer las ecuaciones exactas de la planta, su grado relativo, y la medición completa del vector de estado. En este nuevo enfoque el único requisito es conocer el grado relativo del sistema no lineal afino.

  16. La rentabilidad del error en el aprendizaje de lenguas afines: italiano y español

    OpenAIRE

    Kovács, Renáta

    2014-01-01

    En el presente trabajo se trata de explicar el origen de los errores provenientes de los falsos amigos producidos por la interacción de dos lenguas afines, italiano y español, que pueden darse en diferentes situaciones comunicativas. Nuestra atención se centrará en aquellos falsos amigos con los que han de enfrentarse los hispanohablantes a la hora de aprender el italiano.

  17. Forma de crecimiento en Leptochloa Chloridiformis (Poaceae

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    Mariel G. Perreta

    2000-01-01

    Full Text Available Perreta, M. G., Tivano, J. C. & Vegetti, A. C. 2000. Forma de crecimiento en Leptochloachloridiformis (Poaceae. Darwiniana 38(3-4: 219-226.El objetivo de este trabajo fue analizar la forma de crecimiento de Leptochloa chloridiformis (Hack.Parodi. En esta especie perenne la ramificación ocurre principalmente a través de yemas axilarespresentes en la zona de innovación. Este sistema de ramificación genera una planta cespitosa, en la cual lasconexiones entre unidades estructurales son rizomas cortos. Dependiendo de su posición estas conexio-nes muestran diferentes tendencias en relación a la desarticulación estructural. En algunas plantas seobservó ramificación en la zona de entrenudos largos posiblemente debido a cambios ambientalesrelacionados con las distintas estaciones

  18. Fragments of the key flowering gene GIGANTEA are associated with helitron-type sequences in the Pooideae grass Lolium perenne

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    Langdon Tim

    2009-06-01

    Full Text Available Abstract Background Helitrons are a class of transposable elements which have been identified in a number of species of plants, animals and fungi. They are unique in their proposed rolling-circle mode of replication, have a highly variable copy-number and have been implicated in the restructuring of coding sequences both by their insertion into existing genes and by their incorporation of transcriptionally competent gene fragments. Helitron discovery depends on identifying associated DNA signature sequences and comprehensive evaluation of helitron contribution to a particular genome requires detailed computational analysis of whole genome sequence. Therefore, the role which helitrons have played in modelling non-model plant genomes is largely unknown. Results Cloning of the flowering gene GIGANTEA (GI from a BAC library of the Pooideae grass Lolium perenne (perennial ryegrass identified the target gene and several GI pseudogene fragments spanning the first five exons. Analysis of genomic sequence 5' and 3' of one these GI fragments revealed motifs consistent with helitron-type transposon insertion, specifically a putative 5'-A↓T-3' insertion site containing 5'-TC and CTAG-3' borders with a sub-terminal 16 bp hairpin. Screening of a BAC library of the closely related grass species Festuca pratensis (meadow fescue indicated similar helitron-associated GI fragments present in this genome, as well as non-helitron associated GI fragments derived from the same region of GI. In order to investigate the possible extent of ancestral helitron-activity in L. perenne, a methylation-filtered GeneThresher® genomic library developed from this species was screened for potential helitron 3' hairpin sequences associated with a 3'-CTRR motif. This identified 7 potential helitron hairpin-types present between at least 9 and 51 times within the L. perenne methylation-filtered library. Conclusion This represents evidence for a possible ancestral role for helitrons

  19. Retórica contrastiva y enseñanza del discurso formal en lenguas afines

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    Pilar Robles Garrote

    2014-08-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE El presente artículo trata de evidenciar la utilidad de la retórica contrastiva en la enseñanza del discurso formal en lenguas afines, aportando algunos datos empíricos obtenidos en un análisis lingüístico cuyo objetivo principal es determinar los puntos en común y divergencias encontradas en algunos recursos estilísticos propios del lenguaje formal en lengua española e italiana. Es un estudio de carácter exploratorio realizado a partir de un corpus oral de conferencias dictadas en lengua española e italiana por oradores nativos. Tras analizar y comparar los recursos estilísticos utilizados por los informantes (preguntas, ejemplos, citas y reiteraciones, los resultados revelan que, si bien los recursos del discurso oral formal encontrados en las conferencias analizadas poseen características análogas, existen divergencias entre estas dos lenguas afines que pueden confluir en una percepción distinta del aspecto pragmático.

  20. Morphology of leaf epidermis of Calamagrostis s.l. (Poaceae: Pooideae) in China%禾本科广义拂子茅属的叶表皮形态研究

    Institute of Scientific and Technical Information of China (English)

    马海英; 彭华; 王跃华

    2006-01-01

    禾本科广义拂子茅属Calamagrostis Adans. s.l.是广布于全球温带和热带亚热带高山的一个大属, 常分为拂子茅属Calamagrostis Adans. s.s.和野青茅属Deyeuxia Beauv..对国产5种拂子茅属和26种、1变种野青茅属植物在光镜下进行了叶表皮特征的观察.发现广义拂子茅属植物的叶表皮特征为典型的狐茅型, 很多结构在种间有丰富的变异式样, 如脉间长细胞形状、大小和细胞壁的厚度与弯曲程度, 短细胞形状和分布式样, 硅质体形状和分布式样, 气孔形状和分布式样, 以及刺毛形态和分布式样等.在国产种类中首次发现微乳突结构, 在很多种类中发现刺毛硅质化现象.用UPGMA对15个叶表皮性状进行分析, 结果分为两大支: 具加厚的长细胞、密集分布的短细胞和(或)刺毛以及刺毛硅质化的种类聚为一支;具薄壁的长细胞、较稀疏的短细胞和(或)刺毛以及刺毛不发生硅质化的种类聚为另一支.这种分异与广义拂子茅属的属下系统相关性不大, 但与种的海拔分布有关.前一支的种类大多生长于高海拔(2600 m以上)地区, 而后一支的种类则大多生长在低海拔(2600 m以下)地区.%Calamagrostis Adans. s.l. is a genus with variable definition in which two genera are often recognized in China: Calamagrostis s.s. and Deyeuxia Beauv. In this study, the leaf epidermis of five species of Calamagrostis s.s. and 26 species and one variety of Deyeuxia was examined under light microscopy. Although all the species examined have a Festucoid type epidermis, a number of variations of some epidermal features exist at the species level. This includes variation in morphology and wall thickness of intercostal long cells, shape and distribution patterns of stomata, morphology and distribution patterns of short cells and silica bodies, morphology, silicification, and distribution of prickles, and presence of micropapillae. Fifteen qualitative characters of the leaf epidermis were used in a phenetic analysis. No sharp differences were found between Calamagrostis s.s. and Deyeuxia. However, there are two major clusters in the UPGMA tree. The first cluster includes species with thick-walled long cells, frequent short cells and/or prickles and silicified prickles. The second cluster includes species with thin-walled long cells, infrequent short cells and/or prickles and unsilicified prickles. The results show that leaf epidermal variation is related with environment, but not concordant with any of the infrageneric classifications of the genus. Species in the first cluster are usually distributed at an altitude above 2600 m, while those of the second cluster are generally distributed at an altitude below 2600 m.

  1. Infrageneric classification of the genus Helictochloa Romero Zarco (Poaceae)

    OpenAIRE

    Romero Zarco, Carlos

    2013-01-01

    An infrageneric classification of the genus Helictochloa Romero Zarco (Poaceae) is presented. Three sections are recognized and two new combinations are proposed Unión Europea (fondos FEDER) Ministerio de Economía y Competitividad Junta de Andalucía: Plan Andaluz de Investigación

  2. Taxonomic revision of Microstegium s.str. (Andropogoneae, Poaceae)

    NARCIS (Netherlands)

    Chen, C.-H.; Veldkamp, J.-F.; Kuoh, C.-S.

    2012-01-01

    Microstegium excl. Leptatherum (Andropogoneae, Poaceae) is revised. There are at least 16 species and one variety. By lack of type materials eight names could not be placed, while, moreover, another three were invalidly published. An identification key is provided, synonymy, descriptions, and notes

  3. A taxonomic revision of Germainia (Andropogoneae: Poaceae) in Thailand

    NARCIS (Netherlands)

    Teerawatananon, A.; Sungkaew, S.; Boontia, V.; Hodkinson, T.R.

    2012-01-01

    A taxonomic revision of the genus Germainia (Andropogoneae, Poaceae) in Thailand is presented based on herbarium and field studies, including evidence from morphology, habitats and geographical distribution. Six of the nine recognized Germainia species are found in Thailand. We include a key to the

  4. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

  5. A taxonomic revision of Germainia (Andropogoneae: Poaceae) in Thailand

    NARCIS (Netherlands)

    Teerawatananon, A.; Sungkaew, S.; Boontia, V.; Hodkinson, T.R.

    2012-01-01

    A taxonomic revision of the genus Germainia (Andropogoneae, Poaceae) in Thailand is presented based on herbarium and field studies, including evidence from morphology, habitats and geographical distribution. Six of the nine recognized Germainia species are found in Thailand. We include a key to the

  6. A taxonomic revision of Germainia (Andropogoneae: Poaceae) in Thailand

    OpenAIRE

    Teerawatananon, A.; Sungkaew, S.; Boontia, V.; Hodkinson, T.R.

    2012-01-01

    A taxonomic revision of the genus Germainia (Andropogoneae, Poaceae) in Thailand is presented based on herbarium and field studies, including evidence from morphology, habitats and geographical distribution. Six of the nine recognized Germainia species are found in Thailand. We include a key to the taxa that are currently known from Thailand or may be expected, lists of species synonymies, species descriptions and lists of representative specimens.

  7. PIGD: a database for intronless genes in the Poaceae.

    Science.gov (United States)

    Yan, Hanwei; Jiang, Cuiping; Li, Xiaoyu; Sheng, Lei; Dong, Qing; Peng, Xiaojian; Li, Qian; Zhao, Yang; Jiang, Haiyang; Cheng, Beijiu

    2014-10-01

    Intronless genes are a feature of prokaryotes; however, they are widespread and unequally distributed among eukaryotes and represent an important resource to study the evolution of gene architecture. Although many databases on exons and introns exist, there is currently no cohesive database that collects intronless genes in plants into a single database. In this study, we present the Poaceae Intronless Genes Database (PIGD), a user-friendly web interface to explore information on intronless genes from different plants. Five Poaceae species, Sorghum bicolor, Zea mays, Setaria italica, Panicum virgatum and Brachypodium distachyon, are included in the current release of PIGD. Gene annotations and sequence data were collected and integrated from different databases. The primary focus of this study was to provide gene descriptions and gene product records. In addition, functional annotations, subcellular localization prediction and taxonomic distribution are reported. PIGD allows users to readily browse, search and download data. BLAST and comparative analyses are also provided through this online database, which is available at http://pigd.ahau.edu.cn/. PIGD provides a solid platform for the collection, integration and analysis of intronless genes in the Poaceae. As such, this database will be useful for subsequent bio-computational analysis in comparative genomics and evolutionary studies.

  8. Poaceae Pollen from Southern Brazil: Distinguishing Grasslands (Campos) from Forests by Analyzing a Diverse Range of Poaceae Species

    Science.gov (United States)

    Radaeski, Jefferson N.; Bauermann, Soraia G.; Pereira, Antonio B.

    2016-01-01

    This aim of this study was to distinguish grasslands from forests in southern Brazil by analyzing Poaceae pollen grains. Through light microscopy analysis, we measured the size of the pollen grain, pore, and annulus from 68 species of Rio Grande do Sul. Measurements were recorded of 10 forest species and 58 grassland species, representing all tribes of the Poaceae in Rio Grande do Sul. We measured the polar, equatorial, pore, and annulus diameter. Results of statistical tests showed that arboreous forest species have larger pollen grain sizes than grassland and herbaceous forest species, and in particular there are strongly significant differences between arboreous and grassland species. Discriminant analysis identified three distinct groups representing each vegetation type. Through the pollen measurements we established three pollen types: larger grains (>46 μm), from the Bambuseae pollen type, medium-sized grains (46–22 μm), from herbaceous pollen type, and small grains (Poaceae pollen dataset may be applied to the fossil pollen of Quaternary sediments. PMID:27999585

  9. Poaceae Pollen From Southern Brazil: Distinguishing Grasslands (Campos From Forests by Analyzing a Diverse Range of Poaceae Species

    Directory of Open Access Journals (Sweden)

    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available This aim of this study was to distinguish grasslands from forests in southern Brazil by analyzing Poaceae pollen grains. Through light microscopy analysis, we measured the size of the pollen grain, pore, and annulus from 68 species of Rio Grande do Sul. Measurements were recorded of 10 forest species and 58 grassland species, representing all tribes of the Poaceae in Rio Grande do Sul. We measured the polar, equatorial, pore, and annulus diameter. Results of statistical tests showed that arboreous forest species have larger pollen grain sizes than grassland and herbaceous forest species, and in particular there are strongly significant differences between arboreous and grassland species. Discriminant analysis identified three distinct groups representing each vegetation type. Through the pollen measurements we established three pollen types: larger grains (>46 µm, from the Bambuseae pollen type, medium-sized grains (46–22µm, from herbaceous pollen type, and small grains (<22 µm, from grassland pollen type. The results of our compiled Poaceae pollen dataset may be applied to the fossil pollen of Quaternary sediments.

  10. Poaceae Pollen from Southern Brazil: Distinguishing Grasslands (Campos) from Forests by Analyzing a Diverse Range of Poaceae Species.

    Science.gov (United States)

    Radaeski, Jefferson N; Bauermann, Soraia G; Pereira, Antonio B

    2016-01-01

    This aim of this study was to distinguish grasslands from forests in southern Brazil by analyzing Poaceae pollen grains. Through light microscopy analysis, we measured the size of the pollen grain, pore, and annulus from 68 species of Rio Grande do Sul. Measurements were recorded of 10 forest species and 58 grassland species, representing all tribes of the Poaceae in Rio Grande do Sul. We measured the polar, equatorial, pore, and annulus diameter. Results of statistical tests showed that arboreous forest species have larger pollen grain sizes than grassland and herbaceous forest species, and in particular there are strongly significant differences between arboreous and grassland species. Discriminant analysis identified three distinct groups representing each vegetation type. Through the pollen measurements we established three pollen types: larger grains (>46 μm), from the Bambuseae pollen type, medium-sized grains (46-22 μm), from herbaceous pollen type, and small grains (Poaceae pollen dataset may be applied to the fossil pollen of Quaternary sediments.

  11. Noves poblacions d'Arundo micrantha Lam. (Poaceae) a la Comunitat Valenciana (Espanya)

    OpenAIRE

    Ferrer-Gallego, P. Pablo; Roselló Gimeno, Robert; Vázquez Mora, Juan Ramón; Laguna Lumbreras, Emilio

    2016-01-01

    Se citen noves poblacions d'Arundo micrantha Lam. (Poaceae) localitzades a les províncies de Castelló i València (Espanya). New records of Arundo micrantha Lam. (Poaceae) from Castellón and Valencia provinces are cited.

  12. Afinal, o que querem as mulheres? After all, what do women want?

    Directory of Open Access Journals (Sweden)

    Livia Barbosa

    2011-01-01

    Full Text Available No Brasil e no mundo, as mulheres avançaram consideravelmente em vários setores. Este avanço se deu sempre na busca pela igualdade. Entretanto, como sugerem as pesquisas, este avanço não se deu na medida desejada. Ainda que sejam tão empreendedoras quanto os homens (e em algumas modalidades até mais do que eles, possuam uma média de anos de estudo maior, trabalhem mais e estejam com autoestima elevada, as distâncias a serem vencidas ainda são consideráveis. Além disso, elas continuam almejando um ideal romântico de parceiro, casamento para toda a vida, filhos e família. Neste contexto, a pergunta título me parece deslocada, com as dificuldades encontrando-se justamente na resposta, já que os homens não legitimam estes "quereres", e nem se mostram preparados a ponto de escolherem uma parceira que lhes seja igual. Considerando a autonomia de nossos quereres, nascidos de dinâmicas internas ao gênero ao qual pertencemos e condicionados pela sociedade e pelas mudanças que nela ocorrem, talvez a indagação mais adequada seja: "Afinal o que nós, homens e mulheres, queremos hoje?".In Brazil and the world, women have advanced considerably in various sectors. This breakthrough came when in the pursuit of equality. However, research suggests, this advance and gave no's as you want. Although they are as entrepreneurial as men (and in some manner even more than them have an average years of schooling increased, more and work with self-esteem are high, the distances to be overcome are still considerable. Moreover, they are still aiming for an ideal romantic partner, marriage for life, children and family. In this context, the question title seems out of place, with the difficulty lies precisely in response, since it does not legitimize these men "want", and not prepared to show the point of choosing a partner who will be the same. Given the autonomy of our desires, born of internal dynamics of the genre to which we belong and conditioned

  13. Helechos y afines del santuario de fauna y flora de Iguaque, Boyacá. Colombia

    Directory of Open Access Journals (Sweden)

    Murillo María Teresa

    1996-06-01

    Full Text Available The altitudinal distribution of 31 genera and 62 species of fems and allied plants has been studied along three transects in the Carrizal, Chaina and San Pedro sections. The transects of the Carrizal and San Pedro sections rise to San Pedro
    de Iguaque lagoon trough westem and eastem slopes of the septentrional zone of Fauna and nora Sanctuary of Iguaque. The genera richest in species are polydium with 11 species, Asplenium, Elaphoglossum y Blechnum with 5 species. The typical genera of paramo are lamesonia, Lycopodium, Huperzia, Blechnum and Isoetes The distribution and number of species was compared in three sections: species number is highest in Carrizal section; in San Pedro section the number is low but there are sorne predominant species: Pleridium sguilinum (L. Kuhn, lycopodium thyodies Willd. and Cheílanthes lendigera (Cav. Sw. Of vegetation of Chaina section is a transition of montane low forests. of higher number in this section is probably due to location in the Iguaque or Cane bed river. Of taxa are concentrated between Andean forest and subparamo zones. Fem species seem limited in their distribution and are considered specífic
    in their ecological requirementa.
    Se reconocen 31 géneros y 62 especies de helechos y afines en tres transectos ubicados en los sectores Carrizal, Chaina y San Pedro. En los sectores Carrizal y San Pedro, los transectos ascienden por los flancos occidental y oriental de la parte septentrional del santuario hasta la laguna de Iguaque. Los géneros mejor representados son Polypodium con 11 especies, Aspleuinum, Elaphoglossum y Blechnum con 5 especies. Se encontraron géneros caracteristicos del páramo: lamesonia, lycopodium, huperzia,  Blechnum e Isoetes compara la distribución y el número de especies en los tres sectores: el mayor número de especies se observa en el sector Carrizal; en el sector San Pedro es menor pero se detecta predominio de las especies Pleridium aquiliun (L

  14. Diversidad de orbículas en Poaceae

    Directory of Open Access Journals (Sweden)

    Marcelo R Lovisolo

    2012-06-01

    Full Text Available Anteras de diez especies de Poaceae de la Provincia de Buenos Aires (Argentina fueron investigadas con microscopio electrónico de barrido y de transmisión. Las orbículas pueden ser definidas como corpúsculos de tamaño variable que muestran la misma electrodensidad, reacción a los colorantes, autofluorescencia y resistencia a la acetólisis que la exina del grano de polen. Las orbículas se encuentran revistiendo el interior del lóculo de la antera, a menudo adheridas a una membrana tapetal. En este estudio se identificaron cuatro tipos y cuatro subtipos diferentes de orbículas. Se concluye que los distintos tipos morfológicos de orbículas descriptos en este trabajo son representativos de cada una de las tribus estudiadas, por lo que se sugiere que la morfología de estos corpúsculos podría ser un carácter utilizado en estudios sistemáticos.Orbicules diversity in Poaceae. Anthers of ten species of Poaceae from the province of Buenos Aires (Argentina were investigated with scanning and transmission electron microscopes. The orbicules can be defined as corpuscles of variable size that show the same electron-density, reaction to the dyes, autofluorescence and resistance to acetolysis as pollen exine does. The orbicules are randomly dispersed on the inner anther locule and they are often attached to a tapetal membrane. In this study, four different types and four subtypes of orbicules were identified. We conclude that the different orbicules types described in this work are representative of the studied tribes, and we suggest that the orbicules morphology may be a useful character in systematic studies.

  15. Poaceae pollen in the air depending on the thermal conditions

    Science.gov (United States)

    Myszkowska, Dorota

    2014-07-01

    The relationship between the meteorological elements, especially the thermal conditions and the Poaceae pollen appearance in the air, were analysed as a basis to construct a useful model predicting the grass season start. Poaceae pollen concentrations were monitored in 1991-2012 in Kraków using the volumetric method. Cumulative temperature and effective cumulative temperature significantly influenced the season start in this period. The strongest correlation was seen as the sum of mean daily temperature amplitudes from April 1 to April 14, with mean daily temperature >15 °C and effective cumulative temperature >3 °C during that period. The proposed model, based on multiple regression, explained 57 % of variation of the Poaceae season starts in 1991-2010. When cumulative mean daily temperature increased by 10 °C, the season start was accelerated by 1 day. The input of the interaction between these two independent variables into the factor regression model caused the increase in goodness of model fitting. In 2011 the season started 5 days earlier in comparison with the predicted value, while in 2012 the season start was observed 2 days later compared to the predicted day. Depending on the value of mean daily temperature from March 18th to the 31st and the sum of mean daily temperature amplitudes from April 1st to the 14th, the grass pollen seasons were divided into five groups referring to the time of season start occurrence, whereby the early and moderate season starts were the most frequent in the studied period and they were especially related to mean daily temperature in the second half of March.

  16. Relation between Poaceae pollen concentrations and meteorological factors during 2000–2010 in Timisoara, Romania

    Directory of Open Access Journals (Sweden)

    Nicoleta Ianovici

    2015-12-01

    Full Text Available This paper presents the results of Poaceae pollen seasons from 2000–2010 in Timisoara, Romania. Airborne Poaceae pollen concentrations was high. An increasing trend in the annual totals was observed. The longest pollen season was recorded in the year 2000. The period in which the Poaceae pollen count exceeded the threshold value of 30 grains/m3 lasted from 9 to 46 days. The present study analyzed the dynamics of pollen seasons in relation to meteorological factors. On the basis of Spearman’s correlation test, the strongest positive correlation was found between the Poaceae pollen counts and temperature; and sunshine hours. Daily average relative humidity, atmospheric pressure and precipitation had a negative effect. A multiple regression analysis was applied to determine how much of the total variance in Poaceae pollen counts can be explained by meteorological parameters. The coefficient of determination ranged from 0.245 to 0.460. Our data illustrate the contrasting effects of temperature, wind, relative humidity and rainfall on the concentration of pollen in the air. The optimum conditions for Poaceae pollen release occur during late spring and early summer. The Poaceae pollen remains one of the major aeroallergens in Timisoara area.

  17. Identification and characterization of lineage-specific genes within the Poaceae.

    Science.gov (United States)

    Campbell, Matthew A; Zhu, Wei; Jiang, Ning; Lin, Haining; Ouyang, Shu; Childs, Kevin L; Haas, Brian J; Hamilton, John P; Buell, C Robin

    2007-12-01

    Using the rice (Oryza sativa) sp. japonica genome annotation, along with genomic sequence and clustered transcript assemblies from 184 species in the plant kingdom, we have identified a set of 861 rice genes that are evolutionarily conserved among six diverse species within the Poaceae yet lack significant sequence similarity with plant species outside the Poaceae. This set of evolutionarily conserved and lineage-specific rice genes is termed conserved Poaceae-specific genes (CPSGs) to reflect the presence of significant sequence similarity across three separate Poaceae subfamilies. The vast majority of rice CPSGs (86.6%) encode proteins with no putative function or functionally characterized protein domain. For the remaining CPSGs, 8.8% encode an F-box domain-containing protein and 4.5% encode a protein with a putative function. On average, the CPSGs have fewer exons, shorter total gene length, and elevated GC content when compared with genes annotated as either transposable elements (TEs) or those genes having significant sequence similarity in a species outside the Poaceae. Multiple sequence alignments of the CPSGs with sequences from other Poaceae species show conservation across a putative domain, a novel domain, or the entire coding length of the protein. At the genome level, syntenic alignments between sorghum (Sorghum bicolor) and 103 of the 861 rice CPSGs (12.0%) could be made, demonstrating an additional level of conservation for this set of genes within the Poaceae. The extensive sequence similarity in evolutionarily distinct species within the Poaceae family and an additional screen for TE-related structural characteristics and sequence discounts these CPSGs as being misannotated TEs. Collectively, these data confirm that we have identified a specific set of genes that are highly conserved within, as well as specific to, the Poaceae.

  18. Identification and Characterization of Lineage-Specific Genes within the Poaceae1[W][OA

    Science.gov (United States)

    Campbell, Matthew A.; Zhu, Wei; Jiang, Ning; Lin, Haining; Ouyang, Shu; Childs, Kevin L.; Haas, Brian J.; Hamilton, John P.; Buell, C. Robin

    2007-01-01

    Using the rice (Oryza sativa) sp. japonica genome annotation, along with genomic sequence and clustered transcript assemblies from 184 species in the plant kingdom, we have identified a set of 861 rice genes that are evolutionarily conserved among six diverse species within the Poaceae yet lack significant sequence similarity with plant species outside the Poaceae. This set of evolutionarily conserved and lineage-specific rice genes is termed conserved Poaceae-specific genes (CPSGs) to reflect the presence of significant sequence similarity across three separate Poaceae subfamilies. The vast majority of rice CPSGs (86.6%) encode proteins with no putative function or functionally characterized protein domain. For the remaining CPSGs, 8.8% encode an F-box domain-containing protein and 4.5% encode a protein with a putative function. On average, the CPSGs have fewer exons, shorter total gene length, and elevated GC content when compared with genes annotated as either transposable elements (TEs) or those genes having significant sequence similarity in a species outside the Poaceae. Multiple sequence alignments of the CPSGs with sequences from other Poaceae species show conservation across a putative domain, a novel domain, or the entire coding length of the protein. At the genome level, syntenic alignments between sorghum (Sorghum bicolor) and 103 of the 861 rice CPSGs (12.0%) could be made, demonstrating an additional level of conservation for this set of genes within the Poaceae. The extensive sequence similarity in evolutionarily distinct species within the Poaceae family and an additional screen for TE-related structural characteristics and sequence discounts these CPSGs as being misannotated TEs. Collectively, these data confirm that we have identified a specific set of genes that are highly conserved within, as well as specific to, the Poaceae. PMID:17951464

  19. Siervos y afines en Al-Andalus omeya a la luz de las inscripciones constructivas

    Directory of Open Access Journals (Sweden)

    Juan A. Souto

    2010-01-01

    Full Text Available Se denomina «siervos y afines» a una serie de individuos cuyo rasgo común es su dependencia personal y directa de otra persona. Las cualidades de esa dependencia no son fáciles de definir, y menos los vocablos con que se expresan. Los objetos de estudio de este trabajo son seres humanos cuyo carácter de abd o mawlà está expresamente documentado por las fuentes empleadas; así como otros que aparecen con calificativos de significado quizás menos claro y evidente: asır, fatà,g ulam ys. anıa, y aquellos cuyas vinculaciones vienen dadas por sus nasabs, sus nisbas o bien de forma indirecta, mediante la referencia a su sayyid. Se establece, en la medida de lo posible, el significado de unas y otras nomenclaturas y el papel de sus portadores. El espacio y el periodo cronológico escogidos son al-Andalus y la época de ejercicio efectivo del poder por la dinastía Omeya, es decir, de 711 a 1013, aunque las fuentes empleadas tienen una cronología más estrecha dentro de ese marco. Esas fuentes son las inscripciones constructivas. Entiendo por «inscripción constructiva» todo material escrito desplazando masa de su soporte y cuyo texto hace referencia a un edificio o parte de un edificio, sus autores o sus mecenas.We define «serfs and related characters» as a series of people whose shared feature was a personal and direct dependence on someone else. The characteristics of that dependence are not easy to define, and even less so are the terms they are explained with. The subject at hand in this work are human beings whose abd or mawlà nature is specifically documented by the sources used, as well as others that appear with expressions that may be less clear or obvious: asır, fatà,g ulam ys. anıa, and those whose links are given by their nasabs, their nisbas or indirectly, referring to their sayyid. As far as is possible, the meaning of some or other nomenclatures and the role of their bearers is established. The chronological period and

  20. TaFROG Encodes a Pooideae Orphan Protein That Interacts with SnRK1 and Enhances Resistance to the Mycotoxigenic Fungus Fusarium graminearum.

    Science.gov (United States)

    Perochon, Alexandre; Jianguang, Jia; Kahla, Amal; Arunachalam, Chanemougasoundharam; Scofield, Steven R; Bowden, Sarah; Wallington, Emma; Doohan, Fiona M

    2015-12-01

    All genomes encode taxonomically restricted orphan genes, and the vast majority are of unknown function. There is growing evidence that such genes play an important role in the environmental adaptation of taxa. We report the functional characterization of an orphan gene (Triticum aestivum Fusarium Resistance Orphan Gene [TaFROG]) as a component of resistance to the globally important wheat (T. aestivum) disease, Fusarium head blight. TaFROG is taxonomically restricted to the grass subfamily Pooideae. Gene expression studies showed that it is a component of the early wheat response to the mycotoxin deoxynivalenol (DON), which is a virulence factor produced by the causal fungal agent of Fusarium head blight, Fusarium graminearum. The temporal induction of TaFROG by F. graminearum in wheat spikelets correlated with the activation of the defense Triticum aestivum Pathogenesis-Related-1 (TaPR1) gene. But unlike TaPR1, TaFROG induction by F. graminearum was toxin dependent, as determined via comparative analysis of the effects of wild-type fungus and a DON minus mutant derivative. Using virus-induced gene silencing and overexpressing transgenic wheat lines, we present evidence that TaFROG contributes to host resistance to both DON and F. graminearum. TaFROG is an intrinsically disordered protein, and it localized to the nucleus. A wheat alpha subunit of the Sucrose Non-Fermenting1-Related Kinase1 was identified as a TaFROG-interacting protein based on a yeast two-hybrid study. In planta bimolecular fluorescence complementation assays confirmed the interaction. Thus, we conclude that TaFROG encodes a new Sucrose Non-Fermenting1-Related Kinase1-interacting protein and enhances biotic stress resistance.

  1. Mas, afinal, o que é Educação Física?: um exemplo do simplismo intelectual

    OpenAIRE

    Taffarel,Celi Nelza Zulke; Ortega Escobar, Micheli

    1994-01-01

    O trabalho expõe uma crítica às concepções idealistas que se constituem em referências para o autor do artigo "Mas, afinal, o que é educação física?" e procura responder aos problemas, de ordem filosófica, epistemológica, metodológica e política, levantados pela pergunta. As contribuições das autoras surgem da radicalização da crítica a partir do marco teórico e metodológico materialista-histórico-dialético.

  2. Xi congreso nacional de ingeniería agrícola y áreas afines- conferencias magistrales

    OpenAIRE

    Facultad Nacional de Agronomía, Universidad Nacional de Colombia

    2013-01-01

    En este artículo podemos encontrar las conferencias magistrales de XI Congreso Nacional de Ingeniería Agrícola y Áreas Afines en el que se pueden encontrar las siguientes: Automatización en la industria azucarera de Brasil. Este texto presenta una historia resumida del desarrollo de la industria azucarera en Brasil, con énfasis en la producción de alcohol. Se muestra también, la composición de la matriz energética brasilera y la contribución de la energía proveniente de la biomasa, en especia...

  3. Xi congreso nacional de ingeniería agrícola y áreas afines- conferencias magistrales

    OpenAIRE

    Facultad Nacional de Agronomía, Universidad Nacional de Colombia

    2013-01-01

    En este artículo podemos encontrar las conferencias magistrales de XI Congreso Nacional de Ingeniería Agrícola y Áreas Afines en el que se pueden encontrar las siguientes: Automatización en la industria azucarera de Brasil. Este texto presenta una historia resumida del desarrollo de la industria azucarera en Brasil, con énfasis en la producción de alcohol. Se muestra también, la composición de la matriz energética brasilera y la contribución de la energía proveniente de la biomasa, en especia...

  4. Chemotaxonomy as a tool for interpreting the cryptic diversity of Poaceae pollen

    NARCIS (Netherlands)

    Julier, A.C.M.; Jardine, P.E.; Coe, A.L.; Gosling, W.D.; Lomax, B.H.; Fraser, W.T.

    2016-01-01

    The uniform morphology of different species of Poaceae (grass) pollen means that identification to below family level using light microscopy is extremely challenging. Poor taxonomic resolution reduces recoverable information from the grass pollen record, for example, species diversity and

  5. Poaceae pollen grain size as a tool to distinguish past grasslands in South America: a new methodological approach

    OpenAIRE

    Schüler, Lisa; Behling, Hermann

    2010-01-01

    Despite the dominance of grasslands during the last glacial period, especially in South America, the highly uniform morphology of Poaceae pollen grains has so far allowed only very few palynological studies based on Poaceae pollen. In our study we compare two methods of distinguishing between South American grassland ecosystems based on quantitative morphology of Poaceae pollen grains. We investigated data sets from Páramo in southern Ecuador, Campos de Altitude and Campos in south-eastern an...

  6. Cercosporoid fungi (Mycosphaerellaceae) 3. Species on monocots (Poaceae, true grasses).

    Science.gov (United States)

    Braun, Uwe; Crous, Pedro W; Nakashima, Chiharu

    2015-06-01

    The third part of a series of monographic treatments of cercosporoid fungi (formerly Cercospora s. lat., Mycosphaerellaceae, Ascomycota) continues with a treatment of taxa on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), covering asexual and holomorph species with mycosphaerella-like sexual morphs on true grasses (Poaceae), which were excluded from the second part. The species concerned are keyed out, alphabetically listed, described, illustrated and supplemented by references to previously published descriptions, illustrations, and exsiccatae. A key to the recognised genera and a discussion of taxonomically relevant characters was published in the first part of this series. Several species are lecto- or neotypified. The following taxonomic novelties are introduced: Cercospora barretoana comb. nov., C. cymbopogonicola nom. nov., Cladosporium elymi comb. nov., Passalora agrostidicola sp. nov., P. brachyelytri comb. nov., and P. dichanthii-annulati comb. nov.

  7. Arquivos Brasileiros de Psiquiatria, Neurologia e Ciências Afins: uma fonte com muita história Arquivos Brasileiros de Psiquiatria, Neurologia e Ciências Afins: a source rich in history

    Directory of Open Access Journals (Sweden)

    Cristiana Facchinetti

    2010-12-01

    Full Text Available Surgido em 1905, o Arquivos Brasileiros de Psiquiatria, Neurologia e Ciências Afins foi o primeiro periódico brasileiro especializado na área. Com o nome de Arquivos Brasileiros de Psiquiatria, Neurologia e Medicina Legal, tornou-se, em 1908, veículo de divulgação da Sociedade com o mesmo nome. A partir de 1919 foi publicado como Arquivos Brasileiros de Neuriatria e Psiquiatria. O periódico traz as propostas para a psiquiatria brasileira lideradas por Juliano Moreira, diretor do Hospício Nacional e da Assistência a Alienados do Distrito Federal. Por veicular trabalhos de profissionais do Hospício Nacional, é fonte fundamental para a investigação dos processos diagnósticos e das práticas clínicas e terapêuticas do período. Apresenta-se aqui uma seleção de artigos publicados na revista entre 1905 e 1930, ano da aposentadoria de Moreira.Launched in 1905, the Arquivos Brasileiros de Psiquiatria, Neurologia e Ciências Afins was the first Brazilian periodical specialized in psychiatry, neurology, and related sciences. In 1908, under the new name of Arquivos Brasileiros de Psiquiatria, Neurologia e Medicina Legal, it became the journal of the Society of Psychiatry, Neurology, and Forensic Medicine. Starting in 1919, it was published under the title Arquivos Brasileiros de Neuriatria e Psiquiatria. The periodical presents proposals put forward for this field in Brazil, under the leadership of Juliano Moreira, director of both the National Asylum and of Federal District Assistance for the Insane (Assistência a Alienados do Distrito Federal. Because the journal published articles by healthcare providers from the National Asylum, it is a vital source for researchers of the era's diagnostic processes and clinical and therapeutic practices. This selection of texts was published in its pages between 1905 and 1930, the year Moreira retired.

  8. NIVEL DE APRENDIZAJE DE LA "ESTÁTICA" EN INGENIERIA MECÁNICA Y CARRERAS AFINES EN MEDELLÍN

    Directory of Open Access Journals (Sweden)

    JORGE IVÁN GÓMEZ G

    2011-01-01

    Full Text Available Se evaluó el nivel de aprendizaje de la asignatura Estática dictada en las carreras de Ingeniería Mecánica y afines en la ciudad de Medellín. Para ello se desarrolló una prueba escrita, tipo selección múltiple con única respuesta. La prueba fue respondida por 42 estudiantes muestreados entre quienes habían aprobado la asignatura en el primer semestre de los años 2007 y 2008, en 6 instituciones universitarias de esta ciudad. Los resultados de la prueba, considerando los promedios, muestran como el proceso enseñanza-aprendizaje no satisface el mínimo exigido para aprobar una asignatura, según el sistema de calificación seguido en los pregrados en Colombia.

  9. Dispositivo para generar funciones multivariables afines a tramos con computación on-line del árbol de búsqueda

    OpenAIRE

    2012-01-01

    Método para generar funciones multivariables afines a tramos, en donde se realiza la computación on-line del árbol de búsqueda para la localización del valor de entrada en los politopos de la partición, y la posterior generación de la correspondiente función afín. Asimismo se propone un dispositivo configurable y programable para generar funciones multivariables afines a tramos compuesto por una arquitectura con cuatro bloques funcionales siendo éstos: un bloque uni...

  10. Genome-wide distribution comparative and composition analysis of the SSRs in Poaceae.

    Science.gov (United States)

    Wang, Yi; Yang, Chao; Jin, Qiaojun; Zhou, Dongjie; Wang, Shuangshuang; Yu, Yuanjie; Yang, Long

    2015-02-15

    The Poaceae family is of great importance to human beings since it comprises the cereal grasses which are the main sources for human food and animal feed. With the rapid growth of genomic data from Poaceae members, comparative genomics becomes a convinent method to study genetics of diffierent species. The SSRs (Simple Sequence Repeats) are widely used markers in the studies of Poaceae for their high abundance and stability. In this study, using the genomic sequences of 9 Poaceae species, we detected 11,993,943 SSR loci and developed 6,799,910 SSR primer pairs. The results show that SSRs are distributed on all the genomic elements in grass. Hexamer is the most frequent motif and AT/TA is the most frequent motif in dimer. The abundance of the SSRs has a positive linear relationship with the recombination rate. SSR sequences in the coding regions involve a higher GC content in the Poaceae than that in the other species. SSRs of 70-80 bp in length showed the highest AT/GC base ratio among all of these loci. The result shows the highest polymorphism rate belongs to the SSRs ranged from 30 bp to 40 bp. Using all the SSR primers of Japonica, nineteen universal primers were selected and located on the genome of the grass family. The information of SSR loci, the SSR primers and the tools of mining and analyzing SSR are provided in the PSSRD (Poaceae SSR Database, http://biodb.sdau.edu.cn/pssrd/). Our study and the PSSRD database provide a foundation for the comparative study in the Poaceae and it will accelerate the study on markers application, gene mapping and molecular breeding.

  11. Species groups in the genus Ehrharta (Poaceae in southern Africa

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    G. E. Gibbs Russell

    1987-12-01

    Full Text Available Ehrharta Thunb. is a genus of Gondwanaland distribution with its centre of diversity in the winter rainfall Fynbos Biome of southern Africa. In recent subfamily treatments Ehrharta has proved difficult to place satisfactorily, and during the past five years it has been moved between Bambusoideae and Arundinoideae. However, most previous systematic studies using cryptic characters have covered only four taxa out of about 35. The present study includes all African taxa, and demarcates seven species groups on the basis of both spikelet morphology and leaf blade anatomy. Parallelism and/or convergence in vegetative macromorphology within and between the species groups is widespread, and is similar, in some cases, to adaptations found in other plant families in the Fynbos Biome. However, these macromorphological trends are not reflected in the leaf anatomy. Leaf anatomy is generally consistent with the spikelet morphology. Some anatomical differences between the species groups in Ehrharta appear to be as great as differences between taxa of much higher ranks elsewhere in the Poaceae. This wide range of variability may be related to an early divergence of Ehrharteae from other grasses, as suggested by the Gondwanaland distribution, and may explain the difficulty of placing this fascinating yet baffling genus in a subfamily.

  12. Salt glands in flowering culms of Eriochloa species (Poaceae

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    M. O. Arriaga

    1992-12-01

    Full Text Available Salt glands were found in Eriochloa (Paniceae-Poaceae:  E. monte\\idensis, E. pseudoacrotricha and E. punctata.  They occur on the culms, rachises and secondary ramifications of the inflorescence. The glands are bicellular structures with endodermal tissue at the base. They consist of a basal cell and an apical cell, which is a collecting chamber with a large pore at the top. It is proposed to conserve the term salt gland to designate excretory structures associated with endodermal collecting tissue. The elements present in the glands (detected by the use of X-ray micro-analysis are: Na. Mg. P. S. Cl. K with an increase of the elements from the endodermal tissue to the cap cell. Because of energy needed to transport and excrete salts, salt glands are situated at the base of the inflorescence, which is the zone of maximal development of Kranz structure. It is inferred that  Eriochloa is a facultative halophytic genus, derived recently from a halophytic ancestor.

  13. Genome dynamics explain the evolution of flowering time CCT domain gene families in the Poaceae.

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    James Cockram

    Full Text Available Numerous CCT domain genes are known to control flowering in plants. They belong to the CONSTANS-like (COL and PREUDORESPONSE REGULATOR (PRR gene families, which in addition to a CCT domain possess B-box or response-regulator domains, respectively. Ghd7 is the most recently identified COL gene to have a proven role in the control of flowering time in the Poaceae. However, as it lacks B-box domains, its inclusion within the COL gene family, technically, is incorrect. Here, we show Ghd7 belongs to a larger family of previously uncharacterized Poaceae genes which possess just a single CCT domain, termed here CCT MOTIF FAMILY (CMF genes. We molecularly describe the CMF (and related COL and PRR gene families in four sequenced Poaceae species, as well as in the draft genome assembly of barley (Hordeum vulgare. Genetic mapping of the ten barley CMF genes identified, as well as twelve previously unmapped HvCOL and HvPRR genes, finds the majority map to colinear positions relative to their Poaceae orthologues. Combined inter-/intra-species comparative and phylogenetic analysis of CMF, COL and PRR gene families indicates they evolved prior to the monocot/dicot divergence ∼200 mya, with Poaceae CMF evolution described as the interplay between whole genome duplication in the ancestral cereal, and subsequent clade-specific mutation, deletion and duplication events. Given the proven role of CMF genes in the modulation of cereals flowering, the molecular, phylogenetic and comparative analysis of the Poaceae CMF, COL and PRR gene families presented here provides the foundation from which functional investigation can be undertaken.

  14. Genome dynamics explain the evolution of flowering time CCT domain gene families in the Poaceae.

    Science.gov (United States)

    Cockram, James; Thiel, Thomas; Steuernagel, Burkhard; Stein, Nils; Taudien, Stefan; Bailey, Paul C; O'Sullivan, Donal M

    2012-01-01

    Numerous CCT domain genes are known to control flowering in plants. They belong to the CONSTANS-like (COL) and PREUDORESPONSE REGULATOR (PRR) gene families, which in addition to a CCT domain possess B-box or response-regulator domains, respectively. Ghd7 is the most recently identified COL gene to have a proven role in the control of flowering time in the Poaceae. However, as it lacks B-box domains, its inclusion within the COL gene family, technically, is incorrect. Here, we show Ghd7 belongs to a larger family of previously uncharacterized Poaceae genes which possess just a single CCT domain, termed here CCT MOTIF FAMILY (CMF) genes. We molecularly describe the CMF (and related COL and PRR) gene families in four sequenced Poaceae species, as well as in the draft genome assembly of barley (Hordeum vulgare). Genetic mapping of the ten barley CMF genes identified, as well as twelve previously unmapped HvCOL and HvPRR genes, finds the majority map to colinear positions relative to their Poaceae orthologues. Combined inter-/intra-species comparative and phylogenetic analysis of CMF, COL and PRR gene families indicates they evolved prior to the monocot/dicot divergence ∼200 mya, with Poaceae CMF evolution described as the interplay between whole genome duplication in the ancestral cereal, and subsequent clade-specific mutation, deletion and duplication events. Given the proven role of CMF genes in the modulation of cereals flowering, the molecular, phylogenetic and comparative analysis of the Poaceae CMF, COL and PRR gene families presented here provides the foundation from which functional investigation can be undertaken.

  15. Implications of the plastid genome sequence of typha (typhaceae, poales) for understanding genome evolution in poaceae.

    Science.gov (United States)

    Guisinger, Mary M; Chumley, Timothy W; Kuehl, Jennifer V; Boore, Jeffrey L; Jansen, Robert K

    2010-02-01

    Plastid genomes of the grasses (Poaceae) are unusual in their organization and rates of sequence evolution. There has been a recent surge in the availability of grass plastid genome sequences, but a comprehensive comparative analysis of genome evolution has not been performed that includes any related families in the Poales. We report on the plastid genome of Typha latifolia, the first non-grass Poales sequenced to date, and we present comparisons of genome organization and sequence evolution within Poales. Our results confirm that grass plastid genomes exhibit acceleration in both genomic rearrangements and nucleotide substitutions. Poaceae have multiple structural rearrangements, including three inversions, three genes losses (accD, ycf1, ycf2), intron losses in two genes (clpP, rpoC1), and expansion of the inverted repeat (IR) into both large and small single-copy regions. These rearrangements are restricted to the Poaceae, and IR expansion into the small single-copy region correlates with the phylogeny of the family. Comparisons of 73 protein-coding genes for 47 angiosperms including nine Poaceae genera confirm that the branch leading to Poaceae has significantly accelerated rates of change relative to other monocots and angiosperms. Furthermore, rates of sequence evolution within grasses are lower, indicating a deceleration during diversification of the family. Overall there is a strong correlation between accelerated rates of genomic rearrangements and nucleotide substitutions in Poaceae, a phenomenon that has been noted recently throughout angiosperms. The cause of the correlation is unknown, but faulty DNA repair has been suggested in other systems including bacterial and animal mitochondrial genomes.

  16. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic.

    Science.gov (United States)

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Samatadze, Tatiana E; Twardovska, Maryana O; Zoshchuk, Svyatoslav A; Andreev, Igor O; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  17. Comparative molecular cytogenetic characterization of seven Deschampsia (Poaceae) species.

    Science.gov (United States)

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Zoshchuk, Svyatoslav A; Twardovska, Maryana O; Yurkevich, Olga Yu; Andreev, Igor O; Samatadze, Tatiana E; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2017-01-01

    The genus Deschampsia P. Beauv (Poaceae) involves a group of widespread polymorphic species. Some of them are highly tolerant to stressful and variable environmental conditions, and D. antarctica is one of the only two vascular plants growing in Antarctic. This species is a source of useful for selection traits and a valuable model for studying an environmental stress tolerance in plants. Genome diversity and comparative chromosomal phylogeny within the genus have not been studied yet as karyotypes of most Deschampsia species are poorly investigated. We firstly conducted a comparative molecular cytogenetic analysis of D. antarctica (Antarctic Peninsula) and related species from various localities (D. cespitosa, D. danthonioides, D. elongata, D. flexuosa (= Avenella flexuosa), D. parvula and D. sukatschewii by fluorescence in situ hybridization with 45S and 5S rDNA, DAPI-banding and sequential rapid in situ hybridization with genomic DNA of D. antarctica, D. cespitosa, and D. flexuosa. Based on patterns of distribution of the examined markers, chromosomes of the studied species were identified. Within these species, common features as well as species peculiarities in their karyotypic structure and chromosomal distribution of molecular cytogenetic markers were characterized. Different chromosomal rearrangements were detected in D. antarctica, D. flexuosa, D. elongata and D. sukatschewii. In karyotypes of D. antarctica, D. cespitosa, D. elongata and D. sukatschewii, 0-3 B chromosomes possessed distinct DAPI-bands were observed. Our findings suggest that the genome evolution of the genus Deschampsia involved polyploidy and also different chromosomal rearrangements. The obtained results will help clarify the relationships within the genus Deschampsia, and can be a basis for the further genetic and biotechnological studies as well as for selection of plants tolerant to extreme habitats.

  18. Evaluation of candidate barcoding markers in Orinus (Poaceae).

    Science.gov (United States)

    Su, X; Liu, Y P; Chen, Z; Chen, K L

    2016-04-26

    Orinus is an alpine endemic genus of Poaceae. Because of the imperfect specimens, high level of intraspecific morphological variability, and homoplasies of morphological characters, it is relatively difficult to delimitate species of Orinus by using morphology alone. To this end, the DNA barcoding has shown great potential in identifying species. The present study is the first attempt to test the feasibility of four proposed DNA barcoding markers (matK, rbcL, trnH-psbA, and ITS) in identifying four currently revised species of Orinus from the Qinghai-Tibetan Plateau (QTP). Among all the single-barcode candidates, the differentiation power was the highest for the nuclear internal transcribed spacer (ITS), while the chloroplast barcodes matK (M), rbcL (R), and trnH-psbA (H) could not identify the species. Meanwhile, the differentiation efficiency of the nuclear ITS (I) was also higher than any two- or three-locus combination of chloroplast barcodes, or even a combination of ITS and any chloroplast barcode except H + I and R + I. All the combinations of chloroplast barcodes plus the nuclear ITS, H + I, and R + I differentiated the highest portion of species. The highest differentiation rate for the barcodes or barcode combinations examined here was 100% (H + I and R + I). In summary, this case study showed that the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions in differentiating Orinus species from the QTP. Moreover, combining the ITS region with chloroplast regions may improve the barcoding success rate.

  19. The Mediterranean: the cradle of Anthoxanthum (Poaceae) diploid diversity.

    Science.gov (United States)

    Chumová, Zuzana; Záveská, Eliška; Mandáková, Terezie; Krak, Karol; Trávnícek, Pavel

    2017-08-01

    Knowledge of diploid phylogeny and ecogeography provide a foundation for understanding plant evolutionary history, diversification patterns and taxonomy. The genus Anthoxanthum (vernal grasses, Poaceae) represents a taxonomically intricate polyploid complex with large phenotypic variation and poorly resolved evolutionary relationships. The aims of the study were to reveal: (1) evolutionary lineages of the diploid taxa and their genetic differentiation; (2) the past distribution of the rediscovered 'Mediterranean diploid'; and (3) possible migration routes of diploids in the Mediterranean. A combined approach involving sequencing of two plastid regions ( trnL-trnF and rpl32-trnL ), nrDNA ITS, rDNA FISH analyses, climatic niche characterization and spatio-temporal modelling was used. Among the examined diploid species, only two well-differentiated evolutionary lineages were recognized: Anthoxanthum gracile and A. alpinum . The other taxa - A. aristatum, A. ovatum, A. maderense and the 'Mediterranean diploid' - form a rather intermixed group based on the examined molecular data. In situ rDNA localization enabled identification of the ancestral Anthoxanthum karyotype, shared by A. gracile and two taxa from the crown group. For the studied taxa, ancestral location probabilities for six discrete geographical regions in the Mediterranean were proposed and likely scenarios of gradual expansion from them were suggested. Modelling past and present distributions shows that the 'Mediterranean diploid' has already been occurring in the same localities for 120 000 years. Highly congruent results were obtained and dated the origin and first diversification of Anthoxanthum to the Miocene. The later divergence probably took place in the Pleistocene and started polyploid evolution within the genus. The most recent diversification event is still occurring, and incomplete lineage sorting prevents full diversification of taxa at the molecular level, despite clear separation based on

  20. Auto-ecology of Guadua aff. paraguayana (Poaceae Autoecologia de Guadua aff. paraguayana Döll (Poaceae

    Directory of Open Access Journals (Sweden)

    Franklin Galvão

    2010-02-01

    Full Text Available

    Bamboos are agents of natural remediation, but its outbreak in an already established landscape may
    have an intense repercussion, completely changing the flora of the area. A study to determine the effects of the presence of Guadua aff. paraguayana Döll  (Poaceae found in the last remnants of the riparian forest in the areas of permanent preservation of the Wildlife Refuge of Rio Tibagi - a conservation unit in process of stablishment on the Parana’s second plateau, has been developed. This aggressive and opportunistic woody species develops vigorous tussocks in consequence of its pachymorph rhizome system a form of “short neck”; and gets established only on the higher portions of the degraded flood plain. The tussocks have an average size of 2.79 meters, with 11 stems/ m². The shooting season lasts, on average, four months and occurs between spring and summer. The culms have an average length of 13 m, with an increment of 18 cm/day during the stretch period. The average diameter at breast height is 4.25 cm. The tussocks are formed from only one stem that expands from extremely robust sprouts. When it shoots up over the canopy and receives direct sunlight, it forms a kind of braided branches and leaves capable of hardly increase the shade levels and suppress the established vegetation, changing the local succession patterns.

    doi: 10.4336/2009.pfb.58.05

    Bambus são agentes de remediação natural, mas sua irrupção numa paisagem já estabelecida pode ter repercussão intensa, alterando completamente a florística da área. Para estabelecer os efeitos da presença de Guadua aff. paraguayana Döll (Poaceae – um dos pouco conhecidos bambus maciços do planeta – sobre os últimos remanescentes da Floresta Ombrófila Mista Aluvial, nas áreas de preservação permanente do Refúgio de Vida Silvestre do Rio Tibagi, unidade de conservação em processo de criação no Segundo Planalto Paranaense, est

  1. Register of names and types : a comparison between Mesembryanthemaceae and Poaceae

    Directory of Open Access Journals (Sweden)

    G. E. Gibbs Russell

    1984-12-01

    Full Text Available A register of names and types for southern Africa would make possible a more rapid completion of the Flora of Southern Africa. Registers for Mesembryanthemaceae and Poaceae, families which are similar in number of species and names, but different in distribution and importance, are compared, to give guidelines for an efficient approach to extending the register to include other families.

  2. Development of single-nucleotide polymorphism markers for Bromus tectorum (Poaceae) from a partially sequenced transcriptome

    Science.gov (United States)

    Keith R. Merrill; Craig E. Coleman; Susan E. Meyer; Elizabeth A. Leger; Katherine A. Collins

    2016-01-01

    Premise of the study: Bromus tectorum (Poaceae) is an annual grass species that is invasive in many areas of the world but most especially in the U.S. Intermountain West. Single-nucleotide polymorphism (SNP) markers were developed for use in investigating the geospatial and ecological diversity of B. tectorum in the Intermountain West to better understand the...

  3. Segregation of Leptatherum from Microstegium (Andropogoneae, Poaceae) confirmed by Internal Transcribed Spacer DNA sequences

    NARCIS (Netherlands)

    Chen, C.-H.; Veldkamp, J.F.; Kuoh, C.-S.; Tsai, C.-C.; Chiang, Y.-C.

    2009-01-01

    Phylogenetic analyses of Microstegium (Andropogoneae, Poaceae) and some other Andropogoneae species were conducted inferred from the ITS/5.8S sequences. As a result of this study, Microstegium is polyphyletic. There are two rather distant monophyletic clades, one with Microstegium nudum (type of

  4. Surface properties correlate to the digestibility of hydrothermally pretreated lignocellulosic Poaceae biomass feedstocks

    DEFF Research Database (Denmark)

    Tristan Djajadi, Demi; Hansen, Aleksander R.; Jensen, Anders

    2017-01-01

    and surface content of hemicellulose, lignin, and waxas assessed by ATR-FTIR rather than bulk biomass chemical composition correlated to the recalcitrance of the testedbiomass types. The data provide new insight into how hydrothermal pretreatment severity affects surface propertiesof key Poaceae...

  5. Seteria viridis as a model for pathogen resistance in the Poaceae

    Science.gov (United States)

    Seteria viridis is an effective model system for functional genetics in the C4 Poaceae grasses, which include important crops like maize, sorghum, and sugar cane. The small genome size, short stature, rapid life cycle, and the availability of genetic transformation protocols, make Seteria an attract...

  6. Effects of two citrus-based commercial herbicides on giant reed, Arundo donax L. (Poaceae)

    Science.gov (United States)

    The giant reed, Arundo donax L. (Poaceae), is an invasive weed pest in the United States and other parts of the world, particularly in riparian habitats where it can hinder the flow of water and choke out indigenous vegetation. Conventional approaches to controlling A. donax have not been particular...

  7. 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...

  8. A Comparative Analysis of the Mechanical Role of Leaf Sheaths of Poaceae, Juncaceae, and Cyperaceae

    Directory of Open Access Journals (Sweden)

    Andreas Kempe

    2013-01-01

    Full Text Available Similarities in structural organization of the culm in Poaceae, Juncaceae, and Cyperaceae such as leaf sheaths and the presence of intercalary meristems at every node suggest the same mechanical properties and, accordingly, the same functionality. Meristems are zones of tissue formation, which constitute areas of weakness along the entire culm and provide the basis for rapid shoot elongation. Leaf sheaths clasp the culm preventing the shoot from breaking, ensuring the rigidity to grow erectly and to avoid damage of the meristematic tissue. The mechanical influence of leaf sheaths was investigated in members of Poaceae, Juncaceae, and Cyperaceae in the flowering stage. Mechanical properties of Poa araratica, Bromus erectus, Arrhenatherum elatius (Poaceae, Luzula nivea (Juncaceae, and Carex arctata (Cyperaceae were determined in three-point bending before and after the removal of leaf sheaths. The presence of leaf sheaths results in smoothing the distribution of flexural rigidity and therefore avoids stress peaks. The achieved maxima of relative contribution of leaf sheaths to entire flexural rigidity ranged from 55% up to 81% for Poaceae, 72% for C. arctata, and 40% for L. nivea. Across the investigated families, the mechanical role of leaf sheaths could be verified as essential for culm stability during development and beyond.

  9. Effect of meteorological parameters on Poaceae pollen in the atmosphere of Tetouan (NW Morocco)

    Science.gov (United States)

    Aboulaich, Nadia; Achmakh, Lamiaa; Bouziane, Hassan; Trigo, M. Mar; Recio, Marta; Kadiri, Mohamed; Cabezudo, Baltasar; Riadi, Hassane; Kazzaz, Mohamed

    2013-03-01

    Poaceae pollen is one of the most prevalent aeroallergens causing allergenic reactions. The aim of this study was to characterise the grass pollen season in Tetouan during the years 2008-2010, to analyse the effect of some meteorological parameters on the incidence of the airborne Poaceae pollen, and to establish forecasting variables for daily pollen concentrations. Aerobiological sampling was undertaken over three seasons using the volumetric method. The pollen season started in April and showed the highest pollen index in May and June, when the maximum temperature ranged from 23 to 27 °C, respectively. The annual pollen score recorded varied from year to year between 2,588 and 5,404. The main pollen season lasted 114-173 days, with peak days occurring mainly in May; the highest concentration reached 308 pollen grains/m3. Air temperature was the most important meteorological parameter and correlated positively to daily pollen concentration increase. An increase in relative humidity and precipitation was usually related to a decrease in airborne pollen content. External validation of the models performed using data from 2011 showed that Poaceae pollen concentration can be highly predicted (64.2-78.6 %) from the maximum temperature, its mean concentration for the same day in other years, and its concentration recorded on the previous day. Sensitive patients suffering allergy to Poaceae pollen are at moderate to highest risk of manifesting allergic symptoms to grass pollen over 33-42 days. The results obtained provide new information on the quantitative contribution of the Poaceae pollen to the airborne pollen of Tetouan and on its temporal distribution. Airborne pollen can be surveyed and forecast in order to warn the atopic population.

  10. Desenvolvimento pós-seminal de espécies de Poaceae (Poales Post-seminal development of Poaceae species (Poales

    Directory of Open Access Journals (Sweden)

    Adriana Tiemi Nakamura

    2009-03-01

    Full Text Available O presente estudo objetivou verificar a existência de um padrão do desenvolvimento pós-seminal em Poaceae. Para tanto, foram estudadas as seguintes espécies: Olyra humilis Nees (Bambusoideae; Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae; Chloris elata Nees e Eragrostis solida Desv. (Chloridoideae. Procurou-se também comparar as estruturas da plântula de Poaceae com as demais monocotiledôneas. As espécies estudadas são plantas perenes, rizomatosas, cespitosas e apresentam cariopses de tamanhos diferentes. Apresentam sementes albuminosas; embrião lateral, diferenciado, com raiz endógena (adventícia; cotilédone dividido em hiperfilo (escutelo, bainha reduzida e hipofilo (coleóptilo; coleorriza (raiz primária reduzida e mesocótilo (eixo localizado entre o escutelo e coleóptilo. A presença de epiblasto (folha embrionária foi observada em Olyra humilis, Chloris elata e Eragrostis solida. O desenvolvimento pós-seminal é semelhante nas espécies estudadas e forma um padrão em Poaceae. Primeiramente, observa-se a emissão da coleorriza, que cresce no sentido geotrópico positivo, seguida do coleóptilo e plúmula que crescem em sentido contrário, a partir do desenvolvimento do mesocótilo. As primeiras folhas são semelhantes às folhas definitivas (metafilos das espécies, exceto em Olyra humilis, que são modificadas em catafilos e podem ser interpretadas como caráter basal em Bambusoideae. Raiz primária reduzida (coleorriza e hipofilo modificado em coleóptilo são considerados caracteres derivados em Poaceae, quando comparados com as demais monocotiledôneas.This work has aimed to verify the existence of a pattern of the post-seminal development in Poaceae. Thus, Olyra humilis Nees (Bambusoideae; Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae; Chloris elata Nees e Eragrostis solida Desv. (Chloridoideae have been studied. Besides, it was compared the structures of

  11. Chloroplast DNA inversions and the origin of the grass family (Poaceae).

    OpenAIRE

    Doyle, J.J.; Davis, J I; Soreng, R J; Garvin, D; Anderson, M J

    1992-01-01

    The phylogenetic affinities of the grass family (Poaceae) have long been debated. The chloroplast genomes of at least some grasses have been known to possess three inversions relative to the typical gene arrangement found in most flowering plants. We have surveyed for the presence of these inversions in grasses and other monocots by polymerase chain reaction amplification with primers constructed from sequences flanking the inversion end points. Amplification phenotypes diagnostic for the lar...

  12. Chemotaxonomy as a tool for interpreting the cryptic diversity of Poaceae pollen

    OpenAIRE

    Julier, Adele C.M.; Jardine, Phillip E.; Coe, Angela L.; William D Gosling; Lomax, Barry H.; Fraser, Wesley T.

    2016-01-01

    The uniform morphology of different species of Poaceae (grass) pollen means that identification to below family level using light microscopy is extremely challenging. Poor taxonomic resolution reduces recoverable information from the grass pollen record, for example, species diversity and environmental preferences cannot be extracted. Recent research suggests Fourier Transform Infra-red Spectroscopy (FTIR) can be used to identify pollen grains based on their chemical composition. Here, we pre...

  13. Taxonomic Significance of Glume Morphology and Leaf Epidermal Characteristics in some Taxa of Tribe Aveneae (Poaceae)

    OpenAIRE

    Adel EL-GAZZAR; Monier El-GHANI; Lamiaa SHALABI

    2013-01-01

    The numerical classification of tribe Aveneae (Poaceae) is discussed regarding the glume morphology and silica skeleton morphologies. The present study dealt with 18 species belonging to 10 genera of the tribe to cover as many groups as possible within Aveneae. The total of 31 structural characters and 71 character states were scored comparatively. The resulted data matrix was analyzed under a combination of Euclidean distance measure and Ward’s clustering method included in the program packa...

  14. Bailini, Sonia (2016. La interlengua de lenguas afines. El español de los italianos, el italiano de los españoles. Milano: LED.

    Directory of Open Access Journals (Sweden)

    Floriana di Gesù

    2017-07-01

    Full Text Available El volumen del que se ofrece una reseña analiza el fenómeno de la interlengua de lenguas afines: el español de los aprendientes italianos y el italiano de los aprendientes españoles. El objetivo principal del volumen es el análisis cuantitativo y cualitativo de la interlengua de estas dos tipologías de aprendientes, a través del estudio de dos corpus paralelos y longitudinales.

  15. The chloroplast genome of the hexaploid Spartina maritima (Poaceae, Chloridoideae): Comparative analyses and molecular dating.

    Science.gov (United States)

    Rousseau-Gueutin, M; Bellot, S; Martin, G E; Boutte, J; Chelaifa, H; Lima, O; Michon-Coudouel, S; Naquin, D; Salmon, A; Ainouche, K; Ainouche, M

    2015-12-01

    The history of many plant lineages is complicated by reticulate evolution with cases of hybridization often followed by genome duplication (allopolyploidy). In such a context, the inference of phylogenetic relationships and biogeographic scenarios based on molecular data is easier using haploid markers like chloroplast genome sequences. Hybridization and polyploidization occurred recurrently in the genus Spartina (Poaceae, Chloridoideae), as illustrated by the recent formation of the invasive allododecaploid S. anglica during the 19th century in Europe. Until now, only a few plastid markers were available to explore the history of this genus and their low variability limited the resolution of species relationships. We sequenced the complete chloroplast genome (plastome) of S. maritima, the native European parent of S. anglica, and compared it to the plastomes of other Poaceae. Our analysis revealed the presence of fast-evolving regions of potential taxonomic, phylogeographic and phylogenetic utility at various levels within the Poaceae family. Using secondary calibrations, we show that the tetraploid and hexaploid lineages of Spartina diverged 6-10 my ago, and that the two parents of the invasive allopolyploid S. anglica separated 2-4 my ago via long distance dispersal of the ancestor of S. maritima over the Atlantic Ocean. Finally, we discuss the meaning of divergence times between chloroplast genomes in the context of reticulate evolution. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Plants remember past weather: a study for atmospheric pollen concentrations of Ambrosia, Poaceae and Populus

    Science.gov (United States)

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Sümeghy, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Tusnády, Gábor

    2015-10-01

    After extreme dry (wet) summers or years, pollen production of different taxa may decrease (increase) substantially. Accordingly, studying effects of current and past meteorological conditions on current pollen concentrations for different taxa have of major importance. The purpose of this study is separating the weight of current and past weather conditions influencing current pollen productions of three taxa. Two procedures, namely multiple correlations and factor analysis with special transformation are used. The 11-year (1997-2007) data sets include daily pollen counts of Ambrosia (ragweed), Poaceae (grasses) and Populus (poplar), as well as daily values of four climate variables (temperature, relative humidity, global solar flux and precipitation). Multiple correlations of daily pollen counts with simultaneous values of daily meteorological variables do not show annual course for Ambrosia, but do show definite trends for Populus and Poaceae. Results received using the two methods revealed characteristic similarities. For all the three taxa, the continental rainfall peak and additional local showers in the growing season can strengthen the weight of the current meteorological elements. However, due to the precipitation, big amount of water can be stored in the soil contributing to the effect of the past climate elements during dry periods. Higher climate sensitivity (especially water sensitivity) of the herbaceous taxa ( Ambrosia and Poaceae) can be definitely established compared to the arboreal Populus. Separation of the weight of the current and past weather conditions for different taxa involves practical importance both for health care and agricultural production.

  17. Development of universal genetic markers based on single-copy orthologous (COSII) genes in Poaceae.

    Science.gov (United States)

    Liu, Hailan; Guo, Xiaoqin; Wu, Jiasheng; Chen, Guo-Bo; Ying, Yeqing

    2013-03-01

    KEY MESSAGE : We develop a set of universal genetic markers based on single-copy orthologous (COSII) genes in Poaceae. Being evolutionary conserved, single-copy orthologous (COSII) genes are particularly useful in comparative mapping and phylogenetic investigation among species. In this study, we identified 2,684 COSII genes based on five sequenced Poaceae genomes including rice, maize, sorghum, foxtail millet, and brachypodium, and then developed 1,072 COSII markers whose transferability and polymorphism among five bamboo species were further evaluated with 46 pairs of randomly selected primers. 91.3 % of the 46 primers obtained clear amplification in at least one bamboo species, and 65.2 % of them produced polymorphism in more than one species. We also used 42 of them to construct the phylogeny for the five bamboo species, and it might reflect more precise evolutionary relationship than the one based on the vegetative morphology. The results indicated a promising prospect of applying these markers to the investigation of genetic diversity and the classification of Poaceae. To ease and facilitate access of the information of common interest to readers, a web-based database of the COSII markers is provided ( http://www.sicau.edu.cn/web/yms/PCOSWeb/PCOS.html ).

  18. Salt tolerance and osmotic adjustment of Spartina alterniflora (Poaceae) and the invasive M haplotype of Phragmites australis (Poaceae) along a salinity gradient

    Science.gov (United States)

    Vasquez, Edward A.; Glenn, Edward P.; Guntenspergen, Glenn R.; Brown, J. Jed; Nelson, Stephen G.

    2006-01-01

    An invasive variety of Phragmites australis (Poaceae, common reed), the M haplotype, has been implicated in the spread of this species into North American salt marshes that are normally dominated by the salt marsh grass Spartina alterniflora (Poaceae, smooth cordgrass). In some European marshes, on the other hand, Spartina spp. derived from S. alterniflora have spread into brackish P. australis marshes. In both cases, the non-native grass is thought to degrade the habitat value of the marsh for wildlife, and it is important to understand the physiological processes that lead to these species replacements. We compared the growth, salt tolerance, and osmotic adjustment of M haplotype P. australis and S. alterniflora along a salinity gradient in greenhouse experiments. Spartina alterniflora produced new biomass up to 0.6 M NaCl, whereas P. australis did not grow well above 0.2 M NaCl. The greater salt tolerance of S. alterniflora compared with P. australis was due to its ability to use Na+ for osmotic adjustment in the shoots. On the other hand, at low salinities P. australis produced more shoots per gram of rhizome tissue than did S. alterniflora. This study illustrates how ecophysiological differences can shift the competitive advantage from one species to another along a stress gradient. Phragmites australis is spreading into North American coastal marshes that are experiencing reduced salinities, while Spartina spp. are spreading into northern European brackish marshes that are experiencing increased salinities as land use patterns change on the two continents.

  19. Scanning electron microscopy of the leaf epidermis of Merostachys Spreng. (Poaceae: Bambusoideae Microscopia eletrônica de varredura da epiderme foliar de Merostachys Spreng. (Poaceae: Bambusoideae

    Directory of Open Access Journals (Sweden)

    Doria Maria Saiter Gomes

    2009-06-01

    Full Text Available This study presents data on leaf micromorphology of 13 species of Merostachys Spreng. (Poaceae: Bambusoideae, a neotropical genus with numerous endemic species. Greatest species richness is found in Central and Southern Brazil, with 41 of the 46 species described. Species were collected in the field at the localities: Itatiaia National Park and Tijuca National Park, Rio de Janeiro State; Fontes do Ipiranga State Park, São Paulo state; Santa Teresa, Espírito Santo State and Rio Doce State Park, Minas Gerais State. Dried plant material came from the herbarium at the São Paulo Botany Institute. The presence of prickles, silica bodies and macro hairs may be especially useful in delimiting species.São apresentados dados relativos à micromorfologia foliar de 13 espécies de Merostachys Spreng. (Poaceae:Bambusoideae, um gênero neotropical, com numerosas espécies endêmicas, que tem sua maior diversidade nas regiões central e sul do Brasil, onde ocorrem 41 das 46 espécies descritas. O material coletado foi obtido nas seguintes localidades: Parque Nacional do Itatiaia e Parque Nacional da Tijuca (RJ; Parque Estadual das Fontes do Ipiranga (SP; Propriedade dos Irmãos Martinelli, Vargem Alta, Santa Teresa (ES e Parque Estadual do Rio Doce (MG. As espécies herborizadas são provenientes do herbário do Instituto de Botânica de São Paulo (SP. Atenção especial é dada à presença de cerdas, corpúsculos silicosos e macropêlos, características que podem ser úteis na delimitação das espécies.

  20. Poaceae vs. Abiotic Stress: Focus on Drought and Salt Stress, Recent Insights and Perspectives

    Directory of Open Access Journals (Sweden)

    Simone Landi

    2017-07-01

    Full Text Available Poaceae represent the most important group of crops susceptible to abiotic stress. This large family of monocotyledonous plants, commonly known as grasses, counts several important cultivated species, namely wheat (Triticum aestivum, rice (Oryza sativa, maize (Zea mays, and barley (Hordeum vulgare. These crops, notably, show different behaviors under abiotic stress conditions: wheat and rice are considered sensitive, showing serious yield reduction upon water scarcity and soil salinity, while barley presents a natural drought and salt tolerance. During the green revolution (1940–1960, cereal breeding was very successful in developing high-yield crops varieties; however, these cultivars were maximized for highest yield under optimal conditions, and did not present suitable traits for tolerance under unfavorable conditions. The improvement of crop abiotic stress tolerance requires a deep knowledge of the phenomena underlying tolerance, to devise novel approaches and decipher the key components of agricultural production systems. Approaches to improve food production combining both enhanced water use efficiency (WUE and acceptable yields are critical to create a sustainable agriculture in the future. This paper analyzes the latest results on abiotic stress tolerance in Poaceae. In particular, the focus will be directed toward various aspects of water deprivation and salinity response efficiency in Poaceae. Aspects related to cell wall metabolism will be covered, given the importance of the plant cell wall in sensing environmental constraints and in mediating a response; the role of silicon (Si, an important element for monocots' normal growth and development, will also be discussed, since it activates a broad-spectrum response to different exogenous stresses. Perspectives valorizing studies on landraces conclude the survey, as they help identify key traits for breeding purposes.

  1. Poaceae vs. Abiotic Stress: Focus on Drought and Salt Stress, Recent Insights and Perspectives.

    Science.gov (United States)

    Landi, Simone; Hausman, Jean-Francois; Guerriero, Gea; Esposito, Sergio

    2017-01-01

    Poaceae represent the most important group of crops susceptible to abiotic stress. This large family of monocotyledonous plants, commonly known as grasses, counts several important cultivated species, namely wheat (Triticum aestivum), rice (Oryza sativa), maize (Zea mays), and barley (Hordeum vulgare). These crops, notably, show different behaviors under abiotic stress conditions: wheat and rice are considered sensitive, showing serious yield reduction upon water scarcity and soil salinity, while barley presents a natural drought and salt tolerance. During the green revolution (1940-1960), cereal breeding was very successful in developing high-yield crops varieties; however, these cultivars were maximized for highest yield under optimal conditions, and did not present suitable traits for tolerance under unfavorable conditions. The improvement of crop abiotic stress tolerance requires a deep knowledge of the phenomena underlying tolerance, to devise novel approaches and decipher the key components of agricultural production systems. Approaches to improve food production combining both enhanced water use efficiency (WUE) and acceptable yields are critical to create a sustainable agriculture in the future. This paper analyzes the latest results on abiotic stress tolerance in Poaceae. In particular, the focus will be directed toward various aspects of water deprivation and salinity response efficiency in Poaceae. Aspects related to cell wall metabolism will be covered, given the importance of the plant cell wall in sensing environmental constraints and in mediating a response; the role of silicon (Si), an important element for monocots' normal growth and development, will also be discussed, since it activates a broad-spectrum response to different exogenous stresses. Perspectives valorizing studies on landraces conclude the survey, as they help identify key traits for breeding purposes.

  2. Evolution of heteromeric nitrilase complexes in Poaceae with new functions in nitrile metabolism

    Science.gov (United States)

    Jenrich, Roland; Trompetter, Inga; Bak, Søren; Olsen, Carl Erik; Møller, Birger Lindberg; Piotrowski, Markus

    2007-01-01

    Members of the nitrilase 4 (NIT4) family of higher plants catalyze the conversion of β-cyanoalanine to aspartic acid and asparagine, a key step in cyanide detoxification. Grasses (Poaceae) possess two different NIT4 homologs (NIT4A and NIT4B), but none of the recombinant Poaceae enzymes analyzed showed activity with β-cyanoalanine, whereas protein extracts of the same plants clearly posses this activity. Sorghum bicolor contains three NIT4 isoforms SbNIT4A, SbNIT4B1, and SbNIT4B2. Individually, each isoform does not possess enzymatic activity whereas the heteromeric complexes SbNIT4A/B1 and SbNIT4A/B2 hydrolyze β-cyanoalanine with high activity. In addition, the SbNIT4A/B2 complex accepts additional substrates, the best being 4-hydroxyphenylacetonitrile. Corresponding NIT4A and NIT4B isoforms from other Poaceae species can functionally complement the sorghum isoforms in these complexes. Site-specific mutagenesis of the active site cysteine residue demonstrates that hydrolysis of β-cyanoalanine is catalyzed by the NIT4A isoform in both complexes whereas hydrolysis of 4-hydroxyphenylacetonitrile occurs at the NIT4B2 isoform. 4-Hydroxyphenylacetonitrile was shown to be an in vitro breakdown product of the cyanogenic glycoside dhurrin, a main constituent in S. bicolor. The results indicate that the SbNIT4A/B2 heterocomplex plays a key role in an endogenous turnover of dhurrin proceeding via 4-hydroxyphenylacetonitrile and thereby avoiding release of toxic hydrogen cyanide. The operation of this pathway would enable plants to use cyanogenic glycosides as transportable and remobilizable nitrogenous storage compounds. Through combinatorial biochemistry and neofunctionalizations, the small family of nitrilases has gained diverse biological functions in nitrile metabolism. PMID:18003897

  3. Xi congreso nacional de ingeniería agrícola y áreas afines- resúmenes de presentaciones orales y pósters

    OpenAIRE

    Facultad Nacional de Agronomía, Universidad Nacional de Colombia

    2013-01-01

    En este artículo tenemos los resúmenes de las presentaciones orales y posters del XI Congreso Nacional de Ingeniería Agrícola y Áreas Afines donde se pueden encontrar estos artículos:Dispositivo de bajo costo para la medición de la velocidad del viento.Diseño construcción y calibración de un pluviómetro de cazoletas de bajo costo usando interruptores magnéticos. Diseño, construcción y calibración de un lisímetro usando el efecto moiré.Dispositivo de bajo costo para la medición de radiación.De...

  4. Xi congreso nacional de ingeniería agrícola y áreas afines- resúmenes de presentaciones orales y pósters

    OpenAIRE

    Facultad Nacional de Agronomía, Universidad Nacional de Colombia

    2013-01-01

    En este artículo tenemos los resúmenes de las presentaciones orales y posters del XI Congreso Nacional de Ingeniería Agrícola y Áreas Afines donde se pueden encontrar estos artículos:Dispositivo de bajo costo para la medición de la velocidad del viento.Diseño construcción y calibración de un pluviómetro de cazoletas de bajo costo usando interruptores magnéticos. Diseño, construcción y calibración de un lisímetro usando el efecto moiré.Dispositivo de bajo costo para la medición de radiación.De...

  5. Species of the Poaceae-associated genus Bamboosiella (Thysanoptera, Phlaeothripidae) from China, with three new species.

    Science.gov (United States)

    Dang, Li-Hong; Qiao, Ge-Xia

    2016-11-07

    In the Poaceae-associated genus Bamboosiella Ananthakrishnan, eleven species are here recognized from China, including antennatus sp.n. and longisetis sp.n. from Yunnan, and magnus sp.n. from Hainan. Four species are newly recorded from China, bicoloripes Ananthakrishnan, fasciata Okajima, flavescens Okajima and semiflava Okajima. One species from Zhejiang, Bamboosiella brevibristla Sha, Guo, Feng & Duan is placed as a new synonym of B. exastis (Ananthakrishnan & Kudo). An illustrated identification key is provided to the eleven Bamboosiella species now recognised from China.

  6. A morphological and anatomical study of an annual grass Eremopyrum (Poaceae) in Iran.

    Science.gov (United States)

    Keshavarzi, Maryam; Seifali, Mahvash; Babaii, Khadijeh

    2007-01-01

    Eremopyrum (Poaceae) is distributed in various habitats in Iran. This genus is an Irano touranian floristic element and is represented by five species in Iran. In the morphological study 55 quantitative and qualitative characters were evaluated in 26 populations. It was observed that length of lowermost and uppermost glumes and its awn, spike length and lodicules lengths are diagnostic characters. In anatomical studies, the cross sections of the leaf blade and dorsal epidermis were examined and the stomata index was calculated. Characters as frequency of short and silica cells, number of macro hairs, prickles, subsidiaries, shape and number of vascular bundles are diagnostic. Inter- and intra- specific variation in Eremopyrum is evaluated.

  7. Phalaris canariensis L. (Poaceae: A new alien plant record for Kashmir Himalaya, India

    Directory of Open Access Journals (Sweden)

    Shugufta Rasheed

    2016-03-01

    Full Text Available The correct taxonomic identification assumes first and foremost priority in the scientific documentation of biodiversity. The Kashmir Himalaya, located in the north-western side of the Himalayan biodiversity hotspot, is well-known for its diverse flora which merits immediate scientific documentation. In this context, the present study reports Phalaris canariensis L. (Poaceae as a new alien plant record to the flora of Kashmir Himalaya, India. In this paper, a detailed description, photographs, and comparison of diagnostic characters with allied species are provided to scientifically validate this alien plant record for this Himalayan region.

  8. A new species of Rhopalosiphum (Hemiptera, Aphididae on Chusquea tomentosa (Poaceae, Bambusoideae from Costa Rica

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    Nicolás Pérez-Hidalgo

    2012-01-01

    Full Text Available The new species Rhopalosiphum chusqueae Pérez Hidalgo & Villalobos Muller, is described from apterous viviparous females caught on Chusquea tomentosa in Cerro de la Muerte (Costa Rica. The identity of the species is supported both by the morphological features and by a molecular phylogenetic analysis based on a fragment of the mitochondrial DNA containing the 5’ region of the cytochrome c oxidase 1 (COI and on the nuclear gene coding for the Elongation factor-1 alpha (EF1α. The taxonomic position of the new species is discussed. An identification key to the Aphidinae species living on plants of Bambusoideae (Poaceae is presented.

  9. A new species of Rhopalosiphum (Hemiptera, Aphididae) on Chusquea tomentosa (Poaceae, Bambusoideae) from Costa Rica

    Science.gov (United States)

    Hidalgo, Nicolás Pérez; Martínez-Torres, David; Collantes-Alegre, Jorge Mariano; Muller, William Villalobos; Nafría, Juan M. Nieto

    2012-01-01

    Abstract The new species Rhopalosiphum chusqueae Pérez Hidalgo & Villalobos Muller, is described from apterous viviparous females caught on Chusquea tomentosa in Cerro de la Muerte (Costa Rica). The identity of the species is supported both by the morphological features and by a molecular phylogenetic analysis based on a fragment of the mitochondrial DNA containing the 5’ region of the cytochrome c oxidase 1 (COI) and on the nuclear gene coding for the Elongation factor-1 alpha (EF1α). The taxonomic position of the new species is discussed. An identification key to the Aphidinae species living on plants of Bambusoideae (Poaceae) is presented. PMID:22328859

  10. A new species of Rhopalosiphum (Hemiptera, Aphididae) on Chusquea tomentosa (Poaceae, Bambusoideae) from Costa Rica.

    Science.gov (United States)

    Hidalgo, Nicolás Pérez; Martínez-Torres, David; Collantes-Alegre, Jorge Mariano; Muller, William Villalobos; Nafría, Juan M Nieto

    2012-01-01

    The new species Rhopalosiphum chusqueae Pérez Hidalgo & Villalobos Muller, is described from apterous viviparous females caught on Chusquea tomentosa in Cerro de la Muerte (Costa Rica). The identity of the species is supported both by the morphological features and by a molecular phylogenetic analysis based on a fragment of the mitochondrial DNA containing the 5' region of the cytochrome c oxidase 1 (COI) and on the nuclear gene coding for the Elongation factor-1 alpha (EF1α). The taxonomic position of the new species is discussed. An identification key to the Aphidinae species living on plants of Bambusoideae (Poaceae) is presented.

  11. Complete plastid genome sequence of goosegrass (Eleusine indica) and comparison with other Poaceae.

    Science.gov (United States)

    Zhang, Hui; Hall, Nathan; McElroy, J Scott; Lowe, Elijah K; Goertzen, Leslie R

    2017-02-05

    Eleusine indica, also known as goosegrass, is a serious weed in at least 42 countries. In this paper we report the complete plastid genome sequence of goosegrass obtained by de novo assembly of paired-end and mate-paired reads generated by Illumina sequencing of total genomic DNA. The goosegrass plastome is a circular molecule of 135,151bp in length, consisting of two single-copy regions separated by a pair of inverted repeats (IRs) of 20,919 bases. The large (LSC) and the small (SSC) single-copy regions span 80,667 bases and 12,646 bases, respectively. The plastome of goosegrass has 38.19% GC content and includes 108 unique genes, of which 76 are protein-coding, 28 are transfer RNA, and 4 are ribosomal RNA. The goosegrass plastome sequence was compared to eight other species of Poaceae. Although generally conserved with respect to Poaceae, this genomic resource will be useful for evolutionary studies within this weed species and the genus Eleusine. Copyright © 2016. Published by Elsevier B.V.

  12. Root microbiome relates to plant host evolution in maize and other Poaceae.

    Science.gov (United States)

    Bouffaud, Marie-Lara; Poirier, Marie-Andrée; Muller, Daniel; Moënne-Loccoz, Yvan

    2014-09-01

    Prokaryote-eukaryote interactions are primordial, but host selection of its bacterial community remains poorly understood. Because eukaryote evolution affects numerous traits shaping the ecology of their microbiome, we can expect that many evolutionary changes in the former will have the potential to impact on the composition of the latter. Consequently, the more phylogenetically distant the eukaryotic hosts, the more distinct their associated bacterial communities should be. We tested this with plants, by comparing the bacterial communities associated with maize genotypes or other Poaceae. 16S rRNA taxonomic microarray analysis showed that the genetic distance between rhizobacterial communities correlated significantly with the phylogenetic distance (derived from chloroplastic sequences) between Poaceae genotypes. This correlation was also significant when considering specific bacterial populations from all main bacterial divisions, instead of the whole rhizobacterial community. These results indicate that eukaryotic host's evolutionary history can be a significant factor shaping directly the assembly and composition of its associated bacterial compartment. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Identification of positive selection in disease response genes within members of the Poaceae.

    Science.gov (United States)

    Rech, Gabriel E; Vargas, Walter A; Sukno, Serenella A; Thon, Michael R

    2012-12-01

    Millions of years of coevolution between plants and pathogens can leave footprints on their genomes and genes involved on this interaction are expected to show patterns of positive selection in which novel, beneficial alleles are rapidly fixed within the population. Using information about upregulated genes in maize during Colletotrichum graminicola infection and resources available in the Phytozome database, we looked for evidence of positive selection in the Poaceae lineage, acting on protein coding sequences related with plant defense. We found six genes with evidence of positive selection and another eight with sites showing episodic selection. Some of them have already been described as evolving under positive selection, but others are reported here for the first time including genes encoding isocitrate lyase, dehydrogenases, a multidrug transporter, a protein containing a putative leucine-rich repeat and other proteins with unknown functions. Mapping positively selected residues onto the predicted 3-D structure of proteins showed that most of them are located on the surface, where proteins are in contact with other molecules. We present here a set of Poaceae genes that are likely to be involved in plant defense mechanisms and have evidence of positive selection. These genes are excellent candidates for future functional validation.

  14. Reconstructing the Evolutionary History of Paralogous APETALA1/FRUITFULL-Like Genes in Grasses (Poaceae)

    Science.gov (United States)

    Preston, Jill C.; Kellogg, Elizabeth A.

    2006-01-01

    Gene duplication is an important mechanism for the generation of evolutionary novelty. Paralogous genes that are not silenced may evolve new functions (neofunctionalization) that will alter the developmental outcome of preexisting genetic pathways, partition ancestral functions (subfunctionalization) into divergent developmental modules, or function redundantly. Functional divergence can occur by changes in the spatio-temporal patterns of gene expression and/or by changes in the activities of their protein products. We reconstructed the evolutionary history of two paralogous monocot MADS-box transcription factors, FUL1 and FUL2, and determined the evolution of sequence and gene expression in grass AP1/FUL-like genes. Monocot AP1/FUL-like genes duplicated at the base of Poaceae and codon substitutions occurred under relaxed selection mostly along the branch leading to FUL2. Following the duplication, FUL1 was apparently lost from early diverging taxa, a pattern consistent with major changes in grass floral morphology. Overlapping gene expression patterns in leaves and spikelets indicate that FUL1 and FUL2 probably share some redundant functions, but that FUL2 may have become temporally restricted under partial subfunctionalization to particular stages of floret development. These data have allowed us to reconstruct the history of AP1/FUL-like genes in Poaceae and to hypothesize a role for this gene duplication in the evolution of the grass spikelet. PMID:16816429

  15. Larvicidal and repellent activity of Vetiveria zizaniodes (Poaceae) essential oil against the malaria vector Anopheles stephensi (Liston) (Diptera: Culicidae)

    Science.gov (United States)

    Essential oil extracted by steam distillation of Vetiveria zizanioides (L.) Nash (Poaceae) was evaluated for larvicidal and adult repellent activity against the malaria vector Anopheles stephensi (Liston). Median lethal concentrations (LC50) at 24 h post treatment for instars 1-4 were, respectively,...

  16. Development of novel chloroplast microsatellite markers to identify species in the Agrostis complex (Poaceae) and related genera.

    Science.gov (United States)

    Maria L. Zapiola; Richard C. Cronn; Carol A. Mallory-Smith

    2010-01-01

    We needed a reliable way to identify species and confirm potential interspecific and intergeneric hybrids in a landscape-level study of gene flow from transgenic gylphosate-resistant Agrostis stolonifera (Poaceae) to compatible relatives. We developed 12 new polymorphic chloroplast microsatellite markers to aid in identifying species recipient of...

  17. Potential biological control agents for management of cogongrass [Imperata cylindrica 15 (Cyperales: Poaceae)] in the southeastern USA

    Science.gov (United States)

    Cogongrass, Imperata cylindrica (L.) Palisot de Beauvois (Cyperales: Poaceae), is a noxious invasive weed in the southeastern USA. Surveys for potential biological control agents of cogongrass were conducted in Asia and East Africa from 2013 to 2016. Several insect herbivores were found that may hav...

  18. Inclusion of Visually Impaired in the School Programme Scheduled Visit of the Museu de Astronomia e Ciências Afins (MAST). (Breton Title: Inclusão de Deficientes Visuais no Programa de Visita Escolar Programada do Museu de Astronomia e Ciências Afins (MAST).) Inclusión de Discapacitados Visuales en el Programa Escolar Programado del Museo de Astronomía y Ciencias Afines (MAST)

    Science.gov (United States)

    de Oliveira Gonçalves, Carla; da Conceição Barbosa-Lima, Maria

    2013-07-01

    Inclusive Education in Brazil, contemplated in the 1988 Constitution and in the Law of Guidelines and Bases of National Education (9.394/96) highlights the importance and urgency of promoting inclusive education as a formative element of nationality. Inclusive Education refers to all people who are struggling in school. Inclusion should be in all educational institutions (formal and informal). Our goal in the graduation final task was to report the experience of mediation to visually impaired students of the Instituto Benjamin Constant (IBC) at the Museu de Astronomia e Ciências Afins (MAST), and also suggest some modifications and present new proposals for the School Visit Program (VEP) through a specially constructed apparatus, where the sky can be sensed near the latitude of Rio de Janeiro. A educação inclusiva no Brasil, contemplada na Constituição de 1988 e a Lei de Diretrizes e Bases da Educação Nacional (9.394/96), destaca a importância e urgência de se promover a inclusão escolar como elemento formador da nacionalidade. A educação inclusiva diz respeito a todas as pessoas que enfrentam dificuldades na escola. A inclusão deve estar em todas as instituições educacionais (formais e não formais). Nosso objetivo, no trabalho de final de curso de licenciatura, foi apresentar o relato de experiência de mediação aos alunos deficientes visuais do Instituto Benjamin Constant (IBC) no Museu de Astronomia e Ciências Afins (MAST), as modificações e novas propostas para o Programa de Visita Escolar Programada (VEP) através de um aparelho especialmente construído onde se pode perceber o céu na latitude próxima a do Rio de Janeiro. La educación inclusiva en el Brasil, contemplada en la Constitución de 1988 y en la Ley de Directrices y Bases de la Educación Nacional (9.394/96), destaca la importancia y la urgencia de promover la inclusión escolar como elemento formador de la nacionalidad. La educación inclusiva se refiere a todas las personas

  19. Rapid and recent world-wide diversification of bluegrasses (Poa, Poaceae and related genera.

    Directory of Open Access Journals (Sweden)

    Matthias H Hoffmann

    Full Text Available Rapid species diversifications provide fascinating insight into the development of biodiversity in time and space. Most biological radiations studied to date, for example that of cichlid fishes or Andean lupines, are confined to isolated geographical areas like lakes, islands or island-like regions. Using DNA sequence data of the ribosomal internal transcribed spacer (ITS for many species of the Poa alliance, a group comprising about 775 C3 grass species, revealed rapid and parallel diversifications in various parts of the world. Some of these radiations are restricted to isolated areas like the Andes, whereas others are typical of the lowlands of mainly the northern hemisphere. These radiations thus are not restricted to island-like areas and are seemingly actively ongoing. The ages of the diversifying clades are estimated to be 2.5-0.23 million years (Myr. Conservative diversification rates in the Poa alliance amount to 0.89-3.14 species per Myr, thus are in the order of, or even exceeding, other instances of well-known radiations. The grass radiations of the mainly cold-adapted Poa alliance coincide with the Late Tertiary global cooling, which resulted in the retreat of forests and the subsequent formation of cold-adapted grasslands especially in the northern, but also in parts of the southern hemisphere. The cold tolerance, suggested to be one of the ecological key innovations, may have been acquired during the early diversification of the subfamily Pooideae, but became significant millions of years later during the Pliocene/Pleistocene radiation of the Poa alliance.

  20. Evaluación del rechazo hacia la homosexualidad en estudiantes de medicina y psicología con base en tres escalas conceptualmente afines

    Directory of Open Access Journals (Sweden)

    José Moral de la Rubia

    2013-01-01

    Full Text Available El objetivo de este artículo fue describir el nivel de rechazo hacia la homosexualidad en estudiantes de medicina y psicología del noreste de México con base en tres conceptos afines: actitud, homofobia y homonegatividad internalizada. Las escalas de actitud hacia mujeres lesbianas y hombres homosexuales ( ATLG , homonegatividad internalizada ( HNI-16 y homofobia ( HF-8 fueron aplicadas a una muestra no probabilística de 231 participantes (121 mujeres y 103 hombres. Según las puntuaciones totales, los porcentajes de rechazo hacia la homosexualidad variaron del 12 al 38 % según el instrumento de evaluación ( HF -8 y HNI -16, respectivamente y los porcentajes de rechazo extremo (homofóbico oscilaron entre 1 ( ATLG y HF -8 y 3 % ( HNI -16. Se observaron las medias más altas en las escalas y factores que evalúan rechazo sutil, más rechazo hacia los hombres homosexuales que hacia las mujeres lesbianas y mayor rechazo hacia la homosexualidad en el propio sexo en las mujeres. Se concluye que el nivel de homofobia es bajo, pero una actitud de rechazo sutil persiste en un porcentaje importante de casos. Se sugiere trabajar el rechazo sutil en talleres de diversidad sexual para concienciar sobre el mismo, generar empatía hacia quienes lo sufren y resistencia a su activación en situaciones clínicas.

  1. Identification and analysis of unitary loss of long-established protein-coding genes in Poaceae shows evidences for biased gene loss and putatively functional transcription of relics.

    Science.gov (United States)

    Zhao, Yi; Tang, Liang; Li, Zhe; Jin, Jinpu; Luo, Jingchu; Gao, Ge

    2015-04-18

    Long-established protein-coding genes may lose their coding potential during evolution ("unitary gene loss"). Members of the Poaceae family are a major food source and represent an ideal model clade for plant evolution research. However, the global pattern of unitary gene loss in Poaceae genomes as well as the evolutionary fate of lost genes are still less-investigated and remain largely elusive. Using a locally developed pipeline, we identified 129 unitary gene loss events for long-established protein-coding genes from four representative species of Poaceae, i.e. brachypodium, rice, sorghum and maize. Functional annotation suggested that the lost genes in all or most of Poaceae species are enriched for genes involved in development and response to endogenous stimulus. We also found that 44 mutated genomic loci of lost genes, which we referred as relics, were still actively transcribed, and of which 84% (37 of 44) showed significantly differential expression across different tissues. More interestingly, we found that there were totally five expressed relics may function as competitive endogenous RNA in brachypodium, rice and sorghum genome. Based on comparative genomics and transcriptome data, we firstly compiled a comprehensive catalogue of unitary gene loss events in Poaceae species and characterized a statistically significant functional preference for these lost genes as well showed the potential of relics functioning as competitive endogenous RNAs in Poaceae genomes.

  2. E/Z-Thesinine-O-4'-alpha-rhamnoside, pyrrolizidine conjugates produced by grasses (Poaceae).

    Science.gov (United States)

    Koulman, Albert; Seeliger, Claudine; Edwards, Patrick J B; Fraser, Karl; Simpson, Wayne; Johnson, Linda; Cao, Mingshu; Rasmussen, Susanne; Lane, Geoffrey A

    2008-06-01

    Based on direct infusion mass spectrometry we identified a novel alkaloid as a major component of perennial ryegrass (Lolium perenne). Initial mass spectral data suggested it to be a pyrrolizidine conjugate. As this class of alkaloids has not been described before from grasses, we isolated it to elucidate its structure. The isolated alkaloid proved to be a mixture of two stereoisomers. The structures of the two compounds as determined by 1D and 2D NMR spectroscopy, were E-thesinine-O-4'-alpha-rhamnoside (1) and Z-thesinine-O-4'-alpha-rhamnoside (2). These identifications were supported by the characterisation by GC-MS and optical rotation of (+)-isoretronecanol as the necine base released on alkaline hydrolysis of these alkaloids. 1 and 2 together with the aglycone and a hexoside were also detected in tall fescue (Festuca arundinacea). This is the first report of pyrrolizidine alkaloids produced by grasses (Poaceae).

  3. Development of Polymorphic Microsatellite Markers for Phyllostachys edulis (Poaceae, an Important Bamboo Species in China

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    Wei-Xin Jiang

    2013-06-01

    Full Text Available Premise of the study: Polymorphic microsatellite markers were developed for Phyllostachys edulis (Poaceae, an ecologically and economically important bamboo species in China, to evaluate the genetic diversity and population genetic structure of P. edulis and other Phyllostachys species. Methods and Results: Twenty microsatellite markers were developed and their polymorphisms were tested on 71 samples from three geographically disparate populations. Each locus exhibited between two and 10 alleles with an average of five alleles. Excluding monomorphic loci, observed and expected heterozygosity ranged from zero to one and from 0.041 to 0.676, respectively. Conclusions: These 20 polymorphic microsatellite loci will be useful for studies on the molecular ecology, population genetics, and conservation of P. edulis.

  4. Predicting the Poaceae pollen season: six month-ahead forecasting and identification of relevant features

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    Navares, Ricardo; Aznarte, José Luis

    2017-04-01

    In this paper, we approach the problem of predicting the concentrations of Poaceae pollen which define the main pollination season in the city of Madrid. A classification-based approach, based on a computational intelligence model (random forests), is applied to forecast the dates in which risk concentration levels are to be observed. Unlike previous works, the proposal extends the range of forecasting horizons up to 6 months ahead. Furthermore, the proposed model allows to determine the most influential factors for each horizon, making no assumptions about the significance of the weather features. The performace of the proposed model proves it as a successful tool for allergy patients in preventing and minimizing the exposure to risky pollen concentrations and for researchers to gain a deeper insight on the factors driving the pollination season.

  5. Taxonomic Significance of Glume Morphology and Leaf Epidermal Characteristics in some Taxa of Tribe Aveneae (Poaceae

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    Adel EL-GAZZAR

    2013-05-01

    Full Text Available The numerical classification of tribe Aveneae (Poaceae is discussed regarding the glume morphology and silica skeleton morphologies. The present study dealt with 18 species belonging to 10 genera of the tribe to cover as many groups as possible within Aveneae. The total of 31 structural characters and 71 character states were scored comparatively. The resulted data matrix was analyzed under a combination of Euclidean distance measure and Ward’s clustering method included in the program package PC-ORD version 5. The resulted dendrogram separated the tribe into five basic sub-ordinate groups created from three major groups A, B and C. The taxonomic significance of these results was discussed. The results showed congruence between the clustering and PCA method, in suggesting three major groups and 5 sub-ordinate groups.

  6. La familia Poaceae del distrito de Arahuay (Canta, Lima, Perú

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    Paúl Gonzáles

    2011-08-01

    Full Text Available Se reportan para el distrito de Arahuay (Canta, Lima, Perú (zona baja y media un total de 49 especies de la familia Poaceae agrupadas en 28 géneros, 14 tribus y 4 subfamilias. El género Poa es el más diverso con cinco especies, seguido por Eragrostis y Nassella con cuatro especies cada una. Las especies Calamagrostis spiciformis Hack. ex Stuck., Chloris halophila Parodi, Lamprothyrsus peruvianus Hitchc., Festuca glyceriantha Pilg., Lolium multiflorum Lam. y Poa supina Schrad. son nuevos reportes para el departamento de Lima. Se presentan claves dicotómicas para la determinación de los géneros y para las especies en los casos pertinentes. Para cada especie se incluye datos sobre su hábitat, distribución y el material estudiado.

  7. Predicting the Poaceae pollen season: six month-ahead forecasting and identification of relevant features

    Science.gov (United States)

    Navares, Ricardo; Aznarte, José Luis

    2016-09-01

    In this paper, we approach the problem of predicting the concentrations of Poaceae pollen which define the main pollination season in the city of Madrid. A classification-based approach, based on a computational intelligence model (random forests), is applied to forecast the dates in which risk concentration levels are to be observed. Unlike previous works, the proposal extends the range of forecasting horizons up to 6 months ahead. Furthermore, the proposed model allows to determine the most influential factors for each horizon, making no assumptions about the significance of the weather features. The performace of the proposed model proves it as a successful tool for allergy patients in preventing and minimizing the exposure to risky pollen concentrations and for researchers to gain a deeper insight on the factors driving the pollination season.

  8. Register of names and types in Poaceae: a computerized index for southern Africa

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    G. E. Gibbs Russell

    1983-12-01

    Full Text Available For each name based on or applied to southern African grasses the following data is recorded: name, author, place and date of publication, basionym, cross-reference to other genera, and type specimens. The data is entered into a computer file for sorting in the following ways: by name alphabetically, by place of publication, by genus or by collector of the type specimen. The lists thus produced are directly useful for taxonomic study, and will also be the basis for efforts by staff of the Botanical Research Institute, Pretoria, to acquire copies of all original descriptions and photographs of all type specimens. The methods for compiling the Register worked out for Poaceae can be applied to registers of names in other plant families.

  9. Impact of polyploidy on fertility variation of Mediterranean Arundo L. (Poaceae).

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    Hardion, Laurent; Verlaque, Régine; Rosato, Marcela; Rosselló, Josep A; Vila, Bruno

    2015-05-01

    Failure of seed production in the genus Arundo L. (Poaceae) is often attributed to polyploidy. This study tested the impact of two ploidy levels (2n=12 and 18x) on the fertility of four Mediterranean Arundo. Viable pollen was screened from its production to its germination, and seed occurrence was monitored in admixture or isolated conditions. In addition, insights on restructuration of polyploid genomes were analysed using molecular cytogenetics. Our results show that high ploidy levels do not automatically induce failure of sexual reproduction. The two ploidy levels are able to produce viable pollen and seed set depending on species and cultural conditions. The sterility of A. micrantha (2n=12x) and A. donax (2n=18x) is due to the early failures of gametogenesis steps. For 18x cytotypes of A. donaciformis and A. plinii, seed absence for isolated genotype vs. seed production in admixed culture support their auto-incompatibility.

  10. Phylogenomics of the benzoxazinoid biosynthetic pathway of Poaceae: gene duplications and origin of the Bx cluster

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    Dutartre Leslie

    2012-05-01

    Full Text Available Abstract Background The benzoxazinoids 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA and 2,4-dihydroxy-7- methoxy-1,4-benzoxazin-3-one (DIMBOA, are key defense compounds present in major agricultural crops such as maize and wheat. Their biosynthesis involves nine enzymes thought to form a linear pathway leading to the storage of DI(MBOA as glucoside conjugates. Seven of the genes (Bx1-Bx6 and Bx8 form a cluster at the tip of the short arm of maize chromosome 4 that includes four P450 genes (Bx2-5 belonging to the same CYP71C subfamily. The origin of this cluster is unknown. Results We show that the pathway appeared following several duplications of the TSA gene (α-subunit of tryptophan synthase and of a Bx2-like ancestral CYP71C gene and the recruitment of Bx8 before the radiation of Poaceae. The origins of Bx6 and Bx7 remain unclear. We demonstrate that the Bx2-like CYP71C ancestor was not committed to the benzoxazinoid pathway and that after duplications the Bx2-Bx5 genes were under positive selection on a few sites and underwent functional divergence, leading to the current specific biochemical properties of the enzymes. The absence of synteny between available Poaceae genomes involving the Bx gene regions is in contrast with the conserved synteny in the TSA gene region. Conclusions These results demonstrate that rearrangements following duplications of an IGL/TSA gene and of a CYP71C gene probably resulted in the clustering of the new copies (Bx1 and Bx2 at the tip of a chromosome in an ancestor of grasses. Clustering favored cosegregation and tip chromosomal location favored gene rearrangements that allowed the further recruitment of genes to the pathway. These events, a founding event and elongation events, may have been the key to the subsequent evolution of the benzoxazinoid biosynthetic cluster.

  11. Phylogenomics of the benzoxazinoid biosynthetic pathway of Poaceae: gene duplications and origin of the Bx cluster.

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    Dutartre, Leslie; Hilliou, Frédérique; Feyereisen, René

    2012-05-11

    The benzoxazinoids 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7- methoxy-1,4-benzoxazin-3-one (DIMBOA), are key defense compounds present in major agricultural crops such as maize and wheat. Their biosynthesis involves nine enzymes thought to form a linear pathway leading to the storage of DI(M)BOA as glucoside conjugates. Seven of the genes (Bx1-Bx6 and Bx8) form a cluster at the tip of the short arm of maize chromosome 4 that includes four P450 genes (Bx2-5) belonging to the same CYP71C subfamily. The origin of this cluster is unknown. We show that the pathway appeared following several duplications of the TSA gene (α-subunit of tryptophan synthase) and of a Bx2-like ancestral CYP71C gene and the recruitment of Bx8 before the radiation of Poaceae. The origins of Bx6 and Bx7 remain unclear. We demonstrate that the Bx2-like CYP71C ancestor was not committed to the benzoxazinoid pathway and that after duplications the Bx2-Bx5 genes were under positive selection on a few sites and underwent functional divergence, leading to the current specific biochemical properties of the enzymes. The absence of synteny between available Poaceae genomes involving the Bx gene regions is in contrast with the conserved synteny in the TSA gene region. These results demonstrate that rearrangements following duplications of an IGL/TSA gene and of a CYP71C gene probably resulted in the clustering of the new copies (Bx1 and Bx2) at the tip of a chromosome in an ancestor of grasses. Clustering favored cosegregation and tip chromosomal location favored gene rearrangements that allowed the further recruitment of genes to the pathway. These events, a founding event and elongation events, may have been the key to the subsequent evolution of the benzoxazinoid biosynthetic cluster.

  12. Contrasting evolutionary patterns of the Rp1 resistance gene family in different species of Poaceae.

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    Luo, Sha; Peng, Junhua; Li, Kunpeng; Wang, Min; Kuang, Hanhui

    2011-01-01

    Disease-resistance genes (R-genes) in plants show complex evolutionary patterns. We investigated the evolution of the Rp1 R-gene family in Poaceae, and 409 Rp1 fragments were sequenced from 21 species. Our data showed that the common ancestor of Poaceae had two Rp1 loci, but the number of Rp1 locus in extant species varies from one to five. Some wheat and Zea genotypes have dozens of Rp1 homologues in striking contrast to one or two copies in Brachypodium distachyon. The large number of diverse Rp1 homologues in Zea was the result of duplications followed by extensive sequence exchanges among paralogues, and all genes in maize have evolved in a pattern of Type I R-genes. The high frequency of sequence exchanges did not cause concerted evolution in Zea species, but concerted evolution was obvious between Rp1 homologues from genera Zea and Sorghum. Differentiation of Type I and Type II Rp1 homologues was observed in Oryza species, likely occurred in their common ancestor. One member (Type II R-gene) in the Oryza Rp1 cluster did not change sequences with its paralogues, whereas the other paralogues (Type I R-genes) had frequent sequence exchanges. The functional Pi37 resistance gene in rice was generated through an unequal crossover between two neighboring paralogues followed by four point mutations. The Rp1 homologues in wheat and barley were most divergent, probably due to lack of sequence exchanges among them. Our results shed more light on R-gene evolution, particularly on the differentiation of Type I and Type II R-genes.

  13. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

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    Thaisa S Michelan

    Full Text Available The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment, and we then manipulated the densities of the same native species in a second experiment (density experiment. When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect. Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  14. Native macrophyte density and richness affect the invasiveness of a tropical poaceae species.

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    Michelan, Thaisa S; Thomaz, Sidinei M; Bini, Luis M

    2013-01-01

    The role of the native species richness and density in ecosystem invasibility is a matter of concern for both ecologists and managers. We tested the hypothesis that the invasiveness of Urochloa arrecta (non-native in the Neotropics) is negatively affected by the species richness and abundance of native aquatic macrophytes in freshwater ecosystems. We first created four levels of macrophyte richness in a greenhouse (richness experiment), and we then manipulated the densities of the same native species in a second experiment (density experiment). When the native macrophytes were adults, fragments of U. arrecta were added, and their growth was assessed. Our results from the richness experiment corroborated the hypothesis of a negative relationship between the native species richness and the growth of U. arrecta, as measured by sprout length and root biomass. However, the resistance to invasion was not attributed to the presence of a particular native species with a greater competitive ability. In the density experiment, U. arrecta growth decreased significantly with an increased density of all five of the native species. Density strongly affected the performance of the Poaceae in a negative manner, suggesting that patches that are densely colonized by native macrophytes and less subject to disturbances will be more resistant to invasion than those that are poorly colonized and more commonly subjected to disturbances. Our density experiment also showed that some species exhibit a higher competitive ability than others (sampling effect). Although native richness and abundance clearly limit the colonization and establishment of U. arrecta, these factors cannot completely prevent the invasion of aquatic ecosystems by this Poaceae species.

  15. Complete chloroplast genome sequence of common bermudagrass (Cynodon dactylon (L.) Pers.) and comparative analysis within the family Poaceae.

    Science.gov (United States)

    Huang, Ya-Yi; Cho, Shu-Ting; Haryono, Mindia; Kuo, Chih-Horng

    2017-01-01

    Common bermudagrass (Cynodon dactylon (L.) Pers.) belongs to the subfamily Chloridoideae of the Poaceae family, one of the most important plant families ecologically and economically. This grass has a long connection with human culture but its systematics is relatively understudied. In this study, we sequenced and investigated the chloroplast genome of common bermudagrass, which is 134,297 bp in length with two single copy regions (LSC: 79,732 bp; SSC: 12,521 bp) and a pair of inverted repeat (IR) regions (21,022 bp). The annotation contains a total of 128 predicted genes, including 82 protein-coding, 38 tRNA, and 8 rRNA genes. Additionally, our in silico analyses identified 10 sets of repeats longer than 20 bp and predicted the presence of 36 RNA editing sites. Overall, the chloroplast genome of common bermudagrass resembles those from other Poaceae lineages. Compared to most angiosperms, the accD gene and the introns of both clpP and rpoC1 genes are missing. Additionally, the ycf1, ycf2, ycf15, and ycf68 genes are pseudogenized and two genome rearrangements exist. Our phylogenetic analysis based on 47 chloroplast protein-coding genes supported the placement of common bermudagrass within Chloridoideae. Our phylogenetic character mapping based on the parsimony principle further indicated that the loss of the accD gene and clpP introns, the pseudogenization of four ycf genes, and the two rearrangements occurred only once after the most recent common ancestor of the Poaceae diverged from other monocots, which could explain the unusual long branch leading to the Poaceae when phylogeny is inferred based on chloroplast sequences.

  16. Molecular, phylogenetic and comparative genomic analysis of the cytokinin oxidase/dehydrogenase gene family in the Poaceae.

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    Mameaux, Sabine; Cockram, James; Thiel, Thomas; Steuernagel, Burkhard; Stein, Nils; Taudien, Stefan; Jack, Peter; Werner, Peter; Gray, John C; Greenland, Andy J; Powell, Wayne

    2012-01-01

    The genomes of cereals such as wheat (Triticum aestivum) and barley (Hordeum vulgare) are large and therefore problematic for the map-based cloning of agronomicaly important traits. However, comparative approaches within the Poaceae permit transfer of molecular knowledge between species, despite their divergence from a common ancestor sixty million years ago. The finding that null variants of the rice gene cytokinin oxidase/dehydrogenase 2 (OsCKX2) result in large yield increases provides an opportunity to explore whether similar gains could be achieved in other Poaceae members. Here, phylogenetic, molecular and comparative analyses of CKX families in the sequenced grass species rice, brachypodium, sorghum, maize and foxtail millet, as well as members identified from the transcriptomes/genomes of wheat and barley, are presented. Phylogenetic analyses define four Poaceae CKX clades. Comparative analyses showed that CKX phylogenetic groupings can largely be explained by a combination of local gene duplication, and the whole-genome duplication event that predates their speciation. Full-length OsCKX2 homologues in barley (HvCKX2.1, HvCKX2.2) and wheat (TaCKX2.3, TaCKX2.4, TaCKX2.5) are characterized, with comparative analysis at the DNA, protein and genetic/physical map levels suggesting that true CKX2 orthologs have been identified. Furthermore, our analysis shows CKX2 genes in barley and wheat have undergone a Triticeae-specific gene-duplication event. Finally, by identifying ten of the eleven CKX genes predicted to be present in barley by comparative analyses, we show that next-generation sequencing approaches can efficiently determine the gene space of large-genome crops. Together, this work provides the foundation for future functional investigation of CKX family members within the Poaceae. © 2011 National Institute of Agricultural Botany (NIAB). Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell

  17. Gramíneas (Poaceae bambusiformes del Río de Los Amigos, Madre de Dios, Perú

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    Jean Olivier

    2013-03-01

    Full Text Available La presente nota da a conocer las especies de Poaceae (Gramineae bambusiformes presentes en y alrededor de la concesión para conservación del Rió de Los Amigos en la cuenca del Madre de Dios, sur de la Amazonia peruana. Proporciona claves y material grafico para la identificación de los taxones presentes en la zona.

  18. Modelling the root system architecture of Poaceae. Can we simulate integrated traits from morphological parameters of growth and branching?

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    Pagès, Loïc; Picon-Cochard, Catherine

    2014-10-01

    Our objective was to calibrate a model of the root system architecture on several Poaceae species and to assess its value to simulate several 'integrated' traits measured at the root system level: specific root length (SRL), maximum root depth and root mass. We used the model ArchiSimple, made up of sub-models that represent and combine the basic developmental processes, and an experiment on 13 perennial grassland Poaceae species grown in 1.5-m-deep containers and sampled at two different dates after planting (80 and 120 d). Model parameters were estimated almost independently using small samples of the root systems taken at both dates. The relationships obtained for calibration validated the sub-models, and showed species effects on the parameter values. The simulations of integrated traits were relatively correct for SRL and were good for root depth and root mass at the two dates. We obtained some systematic discrepancies that were related to the slight decline of root growth in the last period of the experiment. Because the model allowed correct predictions on a large set of Poaceae species without global fitting, we consider that it is a suitable tool for linking root traits at different organisation levels. © 2014 INRA. New Phytologist © 2014 New Phytologist Trust.

  19. Seed storage protein gene promoters contain conserved DNA motifs in Brassicaceae, Fabaceae and Poaceae

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    Fauteux François

    2009-10-01

    Full Text Available Abstract Background Accurate computational identification of cis-regulatory motifs is difficult, particularly in eukaryotic promoters, which typically contain multiple short and degenerate DNA sequences bound by several interacting factors. Enrichment in combinations of rare motifs in the promoter sequence of functionally or evolutionarily related genes among several species is an indicator of conserved transcriptional regulatory mechanisms. This provides a basis for the computational identification of cis-regulatory motifs. Results We have used a discriminative seeding DNA motif discovery algorithm for an in-depth analysis of 54 seed storage protein (SSP gene promoters from three plant families, namely Brassicaceae (mustards, Fabaceae (legumes and Poaceae (grasses using backgrounds based on complete sets of promoters from a representative species in each family, namely Arabidopsis (Arabidopsis thaliana (L. Heynh., soybean (Glycine max (L. Merr. and rice (Oryza sativa L. respectively. We have identified three conserved motifs (two RY-like and one ACGT-like in Brassicaceae and Fabaceae SSP gene promoters that are similar to experimentally characterized seed-specific cis-regulatory elements. Fabaceae SSP gene promoter sequences are also enriched in a novel, seed-specific E2Fb-like motif. Conserved motifs identified in Poaceae SSP gene promoters include a GCN4-like motif, two prolamin-box-like motifs and an Skn-1-like motif. Evidence of the presence of a variant of the TATA-box is found in the SSP gene promoters from the three plant families. Motifs discovered in SSP gene promoters were used to score whole-genome sets of promoters from Arabidopsis, soybean and rice. The highest-scoring promoters are associated with genes coding for different subunits or precursors of seed storage proteins. Conclusion Seed storage protein gene promoter motifs are conserved in diverse species, and different plant families are characterized by a distinct combination

  20. Seed storage protein gene promoters contain conserved DNA motifs in Brassicaceae, Fabaceae and Poaceae

    Science.gov (United States)

    Fauteux, François; Strömvik, Martina V

    2009-01-01

    Background Accurate computational identification of cis-regulatory motifs is difficult, particularly in eukaryotic promoters, which typically contain multiple short and degenerate DNA sequences bound by several interacting factors. Enrichment in combinations of rare motifs in the promoter sequence of functionally or evolutionarily related genes among several species is an indicator of conserved transcriptional regulatory mechanisms. This provides a basis for the computational identification of cis-regulatory motifs. Results We have used a discriminative seeding DNA motif discovery algorithm for an in-depth analysis of 54 seed storage protein (SSP) gene promoters from three plant families, namely Brassicaceae (mustards), Fabaceae (legumes) and Poaceae (grasses) using backgrounds based on complete sets of promoters from a representative species in each family, namely Arabidopsis (Arabidopsis thaliana (L.) Heynh.), soybean (Glycine max (L.) Merr.) and rice (Oryza sativa L.) respectively. We have identified three conserved motifs (two RY-like and one ACGT-like) in Brassicaceae and Fabaceae SSP gene promoters that are similar to experimentally characterized seed-specific cis-regulatory elements. Fabaceae SSP gene promoter sequences are also enriched in a novel, seed-specific E2Fb-like motif. Conserved motifs identified in Poaceae SSP gene promoters include a GCN4-like motif, two prolamin-box-like motifs and an Skn-1-like motif. Evidence of the presence of a variant of the TATA-box is found in the SSP gene promoters from the three plant families. Motifs discovered in SSP gene promoters were used to score whole-genome sets of promoters from Arabidopsis, soybean and rice. The highest-scoring promoters are associated with genes coding for different subunits or precursors of seed storage proteins. Conclusion Seed storage protein gene promoter motifs are conserved in diverse species, and different plant families are characterized by a distinct combination of conserved motifs

  1. Updated taxonomic descriptions, iconography, and habitat preferences of Brachypodium distachyon, B. stacei, and B. hybridum (Poaceae

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    Catalán, Pilar

    2016-06-01

    Full Text Available We present an updated morphological revision of the three annual species of the genus Brachypodium (Poaceae: B. distachyon, B. tacei, and B. hybridum, which were recently segregated as independent species from the single-species complex B. distachyon s.l. These three species have been proposed as a model system for grass polyploid speciation, and their genomes have been sequenced. However, despite the increasing number of genomic and population-genetic studies conducted for each of these species, no taxonomic updating has been done on them since their original descriptions. B. stacei, the rarest species of the complex, has a protologue based only on the study of specimens from its type locality in Torrent (Formentera, Spain. In this study we update the taxonomic descriptions of the three species using morphoanatomical data from specimens collected throughout their respective native circum-Mediterranean distributions as well as in other localities where they are non-autochthonous. We also provide icons for each species and information about their habitat preferences and geographic distributions.Presentamos una revisión morfológica actualizada de las tres especies anuales del género Brachypodium (Poaceae, B. distachyon, B. stacei y B. ybridum. Estas dos últimas han sido recientemente segregadas como especies independientes dentro del complejo B. distachyon s.l. Las tres especies han sido propuestas como grupo modelo de especiación poliploide en gramíneas y sus genomas han sido secuenciados. Sin embargo, pese al incremento de estudios genómicos y genético-poblacionales desarrollados en poblaciones de estas especies, no se ha llevado a cabo todavía ninguna actualización taxonómica para las mismas desde que se describieron. El protólogo de B. stacei, la especie más rara del complejo, está basado únicamente en el estudio de especímenes de su localidad clásica en Torrent (Formentera, España. En este estudio actualizamos las

  2. Ultrasound influence on coleoptile length at Poaceae seedlings as valuable criteria in prebreeding and breeding processes

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    Kratovalieva Suzana

    2012-01-01

    Full Text Available The study includes research on the effect of ultrasound on the ability of seed germination and coleoptile development of cereal landraces (fam. Poaceae: oat (Avena sativa L. brodski, rye (Secale cereale L. rakotinska, Triticale svetinikolsko and soft wheat (Triticum aestivum L. govrlevska. The experiment with ultrasound was carried out at frequency of 30-40 kHz on the thermostatic ultrasonic bath. Seeds were sonicated at a constant temperature (25ºC for 15 min. Ultrasound effect is reflected in the length of the coleoptyl and mesocotyl, although in a good deal is genetically predetermined. Coleoptile length was the longest in Triticale (3.3-5.5 cm and approximately the same lengths are evident in rye (3.0-6.1 cm. Concerning the mesocotyl the longest one (5.525 cm ± 0.697 is recorded at rye, even significantly longer than control of oat and Triticale. Longer coleoptile of sonicated seeds indicates faster seedling development, good water supply and rapid development and emergence of first leaves. Correlation coefficient showed very high (0.821 and high R2 (67,472% dependence among variables both, in length of coleoptiles (as dependent variable and mesocotyl (as independent with low standard error (0.225. With the simple use of ultrasound the germination period could be shorten, water supply more efficient, the sowing periods will be shorten and good yields even under conditions of climate change with increased temperatures could be achieved.

  3. Canary grasses (Phalaris, Poaceae): biogeography, molecular dating and the role of floret structure in dispersal.

    Science.gov (United States)

    Voshell, Stephanie M; Hilu, Khidir W

    2014-01-01

    Canary grasses (Phalaris, Poaceae) include 21 species, widely spread throughout the temperate and subtropical regions of the world with two centres of diversity: the Mediterranean Basin and western North America. The genus contains annual and perennial, endemic, cosmopolitan, wild, and invasive species with diploid, tetraploid and hexaploid cytotypes. As such, Phalaris presents an ideal platform to study diversification via historic hybridization and polyploidy events, and geographical dispersal in grasses. We present the first empirical phylogeographic study for Phalaris testing current, intuitive hypotheses on the centres of origin, historic dispersal events and diversification within a geological timeframe. Bayesian methods (beast, version 1.6.2) were used to establish divergence dates, and dispersal-vicariance analyses (rasp, version 2.1b) were implemented for ancestral node reconstructions. Our phylogeographic results indicate that the genus emerged during the Miocene epoch [20.6-8.4 Ma (million years ago)] in the Mediterranean basin followed by dispersal and vicariance events to Africa, Asia and the Americas. We propose that a diploid ancestor of P. arundinacea migrated to western North America via the Bering Strait, where further diversification emerged in the New World. It appears that polyploidy played a major role in the evolution of the genus in the Old World, while diversification in the New World followed a primarily diploid pathway. Dispersal to various parts of the Americas followed different routes. Fertile florets with hairy protruding sterile lemmas showed significant correlation with wider geographical distribution.

  4. Influence of plant silicon in Busseola fusca (Lepidoptera: Noctuidae) larvae - Poaceae interactions.

    Science.gov (United States)

    Juma, G; Ahuya, P O; Ong'amo, G; Le Ru, B; Magoma, G; Silvain, J-F; Calatayud, P-A

    2015-04-01

    The noctuid stem borer Busseola fusca is an important pest of maize and sorghum in Sub-Saharan Africa. The presence of this species occurred mostly on cultivated than on wild habitats. Busseola fusca is oligophagous having a narrow range of a wild grass species. This might be due, in part, to differences in silicon (Si) content in plant tissues between cultivated and wild grasses. In the present study, we have tested this hypothesis by studying the survival and the relative growth rate (RGR) expressed as daily weight gains of B. fusca larvae on maize and six wild host plants, mostly present in the natural habitat where B. fusca occurred, and correlated with their Si contents. Survival and RGR of B. fusca larvae were considerably higher on maize and wild sorghum than on the other grass species, and they were negatively related to plant Si content. This was corroborated with results on RGR from artificial diets amended with increasing levels of Si. In addition, if Si was added to maize growing substrate B. fusca larval growth was significantly reduced confirming the involvement of Si in B. fusca larvae - Poaceae interactions. The results provide insight into the possible mechanisms of oligophagy of B. fusca and provide a correlative support for a physical role of plant endogenous Si in impeding feeding of B. fusca larvae.

  5. Evolution of the bamboos (Bambusoideae; Poaceae): a full plastome phylogenomic analysis.

    Science.gov (United States)

    Wysocki, William P; Clark, Lynn G; Attigala, Lakshmi; Ruiz-Sanchez, Eduardo; Duvall, Melvin R

    2015-03-18

    Bambusoideae (Poaceae) comprise three distinct and well-supported lineages: tropical woody bamboos (Bambuseae), temperate woody bamboos (Arundinarieae) and herbaceous bamboos (Olyreae). Phylogenetic studies using chloroplast markers have generally supported a sister relationship between Bambuseae and Olyreae. This suggests either at least two origins of the woody bamboo syndrome in this subfamily or its loss in Olyreae. Here a full chloroplast genome (plastome) phylogenomic study is presented using the coding and noncoding regions of 13 complete plastomes from the Bambuseae, eight from Olyreae and 10 from Arundinarieae. Trees generated using full plastome sequences support the previously recovered monophyletic relationship between Bambuseae and Olyreae. In addition to these relationships, several unique plastome features are uncovered including the first mitogenome-to-plastome horizontal gene transfer observed in monocots. Phylogenomic agreement with previous published phylogenies reinforces the validity of these studies. Additionally, this study presents the first published plastomes from Neotropical woody bamboos and the first full plastome phylogenomic study performed within the herbaceous bamboos. Although the phylogenomic tree presented in this study is largely robust, additional studies using nuclear genes support monophyly in woody bamboos as well as hybridization among previous woody bamboo lineages. The evolutionary history of the Bambusoideae could be further clarified using transcriptomic techniques to increase sampling among nuclear orthologues and investigate the molecular genetics underlying the development of woody and floral tissues.

  6. Evolutionary relationships in Panicoid grasses based on plastome phylogenomics (Panicoideae; Poaceae).

    Science.gov (United States)

    Burke, Sean V; Wysocki, William P; Zuloaga, Fernando O; Craine, Joseph M; Pires, J Chris; Edger, Patrick P; Mayfield-Jones, Dustin; Clark, Lynn G; Kelchner, Scot A; Duvall, Melvin R

    2016-06-18

    Panicoideae are the second largest subfamily in Poaceae (grass family), with 212 genera and approximately 3316 species. Previous studies have begun to reveal relationships within the subfamily, but largely lack resolution and/or robust support for certain tribal and subtribal groups. This study aims to resolve these relationships, as well as characterize a putative mitochondrial insert in one linage. 35 newly sequenced Panicoideae plastomes were combined in a phylogenomic study with 37 other species: 15 Panicoideae and 22 from outgroups. A robust Panicoideae topology largely congruent with previous studies was obtained, but with some incongruences with previously reported subtribal relationships. A mitochondrial DNA (mtDNA) to plastid DNA (ptDNA) transfer was discovered in the Paspalum lineage. The phylogenomic analysis returned a topology that largely supports previous studies. Five previously recognized subtribes appear on the topology to be non-monophyletic. Additionally, evidence for mtDNA to ptDNA transfer was identified in both Paspalum fimbriatum and P. dilatatum, and suggests a single rare event that took place in a common progenitor. Finally, the framework from this study can guide larger whole plastome sampling to discern the relationships in Cyperochloeae, Steyermarkochloeae, Gynerieae, and other incertae sedis taxa that are weakly supported or unresolved.

  7. High-performance computational analysis and peptide screening from databases of cyclotides from poaceae.

    Science.gov (United States)

    Porto, William F; Miranda, Vivian J; Pinto, Michelle F S; Dohms, Stephan M; Franco, Octavio L

    2016-01-01

    Cyclotides are a family of head-to-tail cyclized peptides containing three conserved disulfide bonds, in a structural scaffold also known as a cyclic cysteine knot. Due to the high degree of cysteine conservation, novel members from this peptide family can be identified in protein databases through a search through regular expression (REGEX). In this work, six novel cyclotide-like precursors from the Poaceae were identified from NCBI's non-redundant protein database by the use of REGEX. Two out of six sequences (named Zea mays L and M) showed an Asp residue in the C-terminal, which indicated that they could be cyclic. Gene expression in maize tissues was investigated, showing that the previously described cyclotide-like Z. mays J is expressed in the roots. According to molecular dynamics, the structure of Z. mays J seems to be stable, despite the putative absence of cyclization. As regards cyclotide evolution, it was hypothesized that this is an outcome from convergent evolution and/or horizontal gene transfer. The results showed that peptide screening from databases should be performed periodically in order to include novel sequences, which are deposited as the databases grow. Indeed, the advances in computational and experimental methods will together help to answer key questions and reach new horizons in defense-related peptide identification. © 2015 Wiley Periodicals, Inc.

  8. Homologies of the flower and inflorescence in the early-divergent grass Anomochloa (Poaceae).

    Science.gov (United States)

    Sajo, M Graça; Pabón-Mora, Natalia; Jardim, Jomar; Stevenson, Dennis W; Rudall, Paula J

    2012-04-01

    The grass subfamily Anomochlooideae is phylogenetically significant as the sister group to all other grasses. Thus, comparison of their structure with that of other grasses could provide clues to the evolutionary origin of these characters. We describe the structure, embryology, and development of the flower and partial inflorescence of the monotypic Brazilian grass Anomochloa marantoidea. We compare these features with those of other early-divergent grasses such as Pharus and Streptochaeta and closely related Poales such as Ecdeiocolea. Anomochloa possesses several features that are characteristic of Poaceae, notably a scutellum, a solid style, reduced stamen number, and an ovary with a single ovule that develops into a single indehiscent fruit. Interpretation of floral patterning in Anomochloa is problematic because the ramification pattern of the florets places the bracts and axes in unusual positions relative to the primary inflorescence axis. Our study indicates that there is a single abaxial carpel in Anomochloa, probably due to a cryptic type of pseudomonomery in Anomochloa that resembles the pseudomonomery of other grasses. On the other hand, the Anomochloa flower differs from the "typical" grass flower in lacking lodicules and possessing four stamens, in contrast with the tristaminate condition that characterizes many other grasses. Using the median part of the innermost bract as a locator, we tentatively homologize the inner bract of the Anomochloa partial inflorescence with the palea of other grasses. In this interpretation, the pattern of monosymmetry due to stamen suppression differs from that of Ecdeiocolea.

  9. Intergenomic Rearrangements after Polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae) Affected by Environmental Factors

    Science.gov (United States)

    Wang, Qiuxia; Liu, Huitao; Gao, Ainong; Yang, Xinming; Liu, Weihua; Li, Xiuquan; Li, Lihui

    2012-01-01

    Polyploidization is a major evolutionary process. Approximately 70–75% species of Triticeae (Poaceae) are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng) J.L.Yang et al. (2n = 6x = 42, StStPPYY), collected from different environments, were studied using genome in situ hybridization (GISH). We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15%) and Y (22.22%), in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05). The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01). Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution. PMID:22363542

  10. Morphology and anatomy of the diaspores and seedling of Paspalum (Poaceae, Poales).

    Science.gov (United States)

    Eichemberg, Mayra T; Scatena, Vera L

    2013-01-01

    The knowledge regarding of the diaspore and post-seminal development of Paspalum L. is important for grassland biodiversity conservation, based on their representativeness and genetic improvement of forage. The morphology of the diaspore and the post-seminal development of Paspalum dilatatum Poir. (rhizomatous), P. mandiocanum Trin. var. subaequiglume Barreto (stoloniferous), P. pumilum Nees. (decumbent caespitose) and P. urvillei Steud. (erect caespitose) was described to distinguish species with different growth forms and to survey the characters useful for taxonomy. P. dilatatum differs by presenting oval diaspores larger than the others, with five prominent nerves and trichomes; P. urvillei presents diaspores with one central nerve that is more developed than the two lateral nerves and trichomes; P. mandiocanum var. subaequiglume presents diaspores with trichomes only in the margin; and P. pumilum differs by presenting glabrous diaspores. The caryopsis involves the seed that presents the differentiated embryo and disposed laterally, an elliptical hilum in all of the studied species and a rostellum in P. dilatatum and P. mandiocanum var. subaequiglume. The post-seminal development is similar in the four species and begins with germination that is marked by the emergence of the coleorhiza, followed by the coleoptile. These characteristics are common to other Poaceae previously studied, indicating a pattern to the family and do not distinguish the growth forms.

  11. Morphology and anatomy of the diaspores and seedling of Paspalum (Poaceae, Poales

    Directory of Open Access Journals (Sweden)

    MAYRA T. EICHEMBERG

    2013-09-01

    Full Text Available ABSTRACT The knowledge regarding of the diaspore and post-seminal development of Paspalum L. is important for grassland biodiversity conservation, based on their representativeness and genetic improvement of forage. The morphology of the diaspore and the post-seminal development of Paspalum dilatatum Poir. (rhizomatous, P. mandiocanum Trin. var. subaequiglume Barreto (stoloniferous, P. pumilum Nees. (decumbent caespitose and P. urvillei Steud. (erect caespitose was described to distinguish species with different growth forms and to survey the characters useful for taxonomy. P. dilatatum differs by presenting oval diaspores larger than the others, with five prominent nerves and trichomes; P. urvillei presents diaspores with one central nerve that is more developed than the two lateral nerves and trichomes; P. mandiocanum var. subaequiglume presents diaspores with trichomes only in the margin; and P. pumilum differs by presenting glabrous diaspores. The caryopsis involves the seed that presents the differentiated embryo and disposed laterally, an elliptical hilum in all of the studied species and a rostellum in P. dilatatum and P. mandiocanum var. subaequiglume. The post-seminal development is similar in the four species and begins with germination that is marked by the emergence of the coleorhiza, followed by the coleoptile. These characteristics are common to other Poaceae previously studied, indicating a pattern to the family and do not distinguish the growth forms.

  12. Structural features of the salt glands of the leaf of Distichlis spicata 'Yensen 4a' (Poaceae).

    Science.gov (United States)

    Semenova, Galina A; Fomina, Irina R; Biel, Karl Y

    2010-04-01

    The epidermal salt glands of the leaf of Distichlis spicata 'Yensen 4a' (Poaceae) have a direct contact with one or two water-storing parenchyma cells, which act as collecting cells. A vacuole occupying almost the whole volume of the collecting cell has a direct exit into the extracellular space (apoplast) through the invaginations of the parietal layer of the cytoplasm, which is interrupted in some areas so that the vacuolar-apoplastic continuum is separated only by a single thin membrane, which looks as a valve. On the basis of ultrastructural morphological data (two shapes of the extracellular channels, narrow and extended, are found in basal cells), the hypothesis on the mechanical nature of the salt pump in the basal cell of Distichlis leaf salt gland is proposed. According to the hypothesis, a driving force giving ordered motion to salt solution from the vacuole of the collecting cell through the basal cell of the salt gland to cap cell arises from the impulses of a mechanical compression-expansion of plasma membrane, which penetrates the basal cell in the form of extracellular channels. The acts of compression-expansion of these extracellular channels can be realized by numerous microtubules present in the basal cell cytoplasm.

  13. IMPROVING WHEAT TRITICUM AESTIVUM L. BY INTERSPECIFIC AND INTERGENERIC HYBRIDIZATION WITH POACEAE FAMILY SPECIES

    Directory of Open Access Journals (Sweden)

    Czaplicki A.Z.

    2012-08-01

    Full Text Available The related species of the family Poaceae (Triticeae are the source of unprecedented new genes that allow the extension of genetic variation of common wheat Triticum aestivum L. These species have similar homoeologous chromosomes and rDNA sequences very similar to T. aestivum L. [1-3]. This allows the introgression of alien genes and their incorporation into the genomes A, B and D of wheat, where they can function permanently in the wheat genetic systems. Many of them have already been transferred to the varieties of T. aestivum L. [4].The experimental material consisted of 28 lines of winter wheat obtained using the interspecific and intergeneric hybridization of T. aestivum L. with alien species T. durum Desf., T. timopheevii Zhuk., Lolium perenne L. and Aegilops speltoides Taush. Among them, 15 lines were developed from the cross-combination with tetraploid species (AABB T. durum Desf., 4 lines from the combination with other tetraploid species of different genome composition (AAGG T. timopheevii Zhuk., 4 lines from cross with L. perenne L. and 5 lines were the double hybrids (three-generic derived with two related species, T. durum Desf. (AABB and Ae. speltoides Taush (BB.The anther culture method was used for obtaining DH lines from these interspecific and intergeneric hybrids. In in vitro culture 124 green plants were regenerated. The method of cluster analysis grouped hybrids in terms of comprehensive general similarity of the studied traits.

  14. Factors responsible for Honckenya peploides (Caryophyllaceae) and Leymus mollis (Poaceae) spatial segregation on subarctic coastal dunes.

    Science.gov (United States)

    Gagné, Jean-Michel; Houle, Gilles

    2002-03-01

    Low water and nutrient availability and significant sand movement, salt spray, and soil salinity are typical of coastal dunes. These conditions are generally unfavorable for the various life stages of plants and especially for seedlings. However, the intensity of these stresses decreases landward, even over short distances, with significant effects on community composition. On coastal dunes in subarctic Québec, Canada, Honckenya peploides (Caryophyllaceae) colonizes the upper beach where it forms small mounds called embryo dunes. Leymus mollis (Poaceae) is mostly restricted to the foredune; however, a few individuals successfully establish on the upper beach, particularly on embryo dunes. We hypothesized that this differential distribution is associated with differences in the tolerance of the two species' seedlings to physical stresses. Honckenya peploides and L. mollis seedling tolerance to sand burial, salt spray, soil salinity, and nutrient and water availability was assessed in greenhouse experiments. Unexpectedly, our results showed that tolerance to sand burial, salt spray, and soil salinity was lower for H. peploides than for L. mollis. If seeds are available and seedlings tolerate the conditions prevailing on the upper beach well, why are mature L. mollis individuals rare in this habitat? We suggest that massive abrasion events (e.g., violent storm waves and ice thrust) restrict the presence of the species on the upper beach.

  15. Intergenomic rearrangements after polyploidization of Kengyilia thoroldiana (Poaceae: Triticeae affected by environmental factors.

    Directory of Open Access Journals (Sweden)

    Qiuxia Wang

    Full Text Available Polyploidization is a major evolutionary process. Approximately 70-75% species of Triticeae (Poaceae are polyploids, involving 23 genomes. To investigate intergenomic rearrangements after polyploidization of Triticeae species and to determine the effects of environmental factors on them, nine populations of a typical polyploid Triticeae species, Kengyilia thoroldiana (Keng J.L.Yang et al. (2n = 6x = 42, StStPPYY, collected from different environments, were studied using genome in situ hybridization (GISH. We found that intergenomic rearrangements occurred between the relatively large P genome and the small genomes, St (8.15% and Y (22.22%, in polyploid species via various types of translocations compared to their diploid progenitors. However, no translocation was found between the relatively small St and Y chromosomes. Environmental factors may affect rearrangements among the three genomes. Chromosome translocations were significantly more frequent in populations from cold alpine and grassland environments than in populations from valley and lake-basin habitats (P<0.05. The relationship between types of chromosome translocations and altitude was significant (r = 0.809, P<0.01. Intergenomic rearrangements associated with environmental factors and genetic differentiation of a single basic genome should be considered as equally important genetic processes during species' ecotype evolution.

  16. Phenotypic plasticity, precipitation, and invasiveness in the fire-promoting grass Pennisetum setaceum (Poaceae).

    Science.gov (United States)

    Poulin, Jessica; Sakai, Ann K; Weller, Stephen G; Nguyen, Tan

    2007-04-01

    Invasiveness may result from genetic variation and adaptation or phenotypic plasticity, and genetic variation in fitness traits may be especially critical. Pennisetum setaceum (fountain grass, Poaceae) is highly invasive in Hawaii (HI), moderately invasive in Arizona (AZ), and less invasive in southern California (CA). In common garden experiments, we examined the relative importance of quantitative trait variation, precipitation, and phenotypic plasticity in invasiveness. In two very different environments, plants showed no differences by state of origin (HI, CA, AZ) in aboveground biomass, seeds/flower, and total seed number. Plants from different states were also similar within watering treatment. Plants with supplemental watering, relative to unwatered plants, had greater biomass, specific leaf area (SLA), and total seed number, but did not differ in seeds/flower. Progeny grown from seeds produced under different watering treatments showed no maternal effects in seed mass, germination, biomass or SLA. High phenotypic plasticity, rather than local adaptation is likely responsible for variation in invasiveness. Global change models indicate that temperature and precipitation patterns over the next several decades will change, although the direction of change is uncertain. Drier summers in southern California may retard further invasion, while wetter summers may favor the spread of fountain grass.

  17. Large multi-gene phylogenetic trees of the grasses (Poaceae): progress towards complete tribal and generic level sampling.

    Science.gov (United States)

    Bouchenak-Khelladi, Yanis; Salamin, Nicolas; Savolainen, Vincent; Forest, Felix; Bank, Michelle van der; Chase, Mark W; Hodkinson, Trevor R

    2008-05-01

    In this paper we included a very broad representation of grass family diversity (84% of tribes and 42% of genera). Phylogenetic inference was based on three plastid DNA regions rbcL, matK and trnL-F, using maximum parsimony and Bayesian methods. Our results resolved most of the subfamily relationships within the major clades (BEP and PACCMAD), which had previously been unclear, such as, among others the: (i) BEP and PACCMAD sister relationship, (ii) composition of clades and the sister-relationship of Ehrhartoideae and Bambusoideae + Pooideae, (iii) paraphyly of tribe Bambuseae, (iv) position of Gynerium as sister to Panicoideae, (v) phylogenetic position of Micrairoideae. With the presence of a relatively large amount of missing data, we were able to increase taxon sampling substantially in our analyses from 107 to 295 taxa. However, bootstrap support and to a lesser extent Bayesian inference posterior probabilities were generally lower in analyses involving missing data than those not including them. We produced a fully resolved phylogenetic summary tree for the grass family at subfamily level and indicated the most likely relationships of all included tribes in our analysis.

  18. Taxonomic significance of leaf anatomy of Aniselytron (Poaceae) as an evidence to support its generic validity against Calamagrostis s. l.

    Science.gov (United States)

    Ma, Hai-Ying; Peng, Hua; Li, De-Zhu

    2005-12-01

    A comparative study of leaf anatomy on Aniselytron Merr. and Calamagrostis Adans. s. l. was conducted to review the systematic status of Aniselytron Merr. Calamagrostis s. l. exhibits wide variation in many features, but basic leaf structures of the genus remain constant: absence of a midrib-keel; median and large vascular bundles are central, with double sheaths, accompanied by girders both adaxially and abaxially; prickles have a bulbous base and are not sunken; the abaxial epidermal cells are short and wide and relatively thick-walled. Aniselytron differs from Calamagrostis s. l. in: midrib-keel is present, consisting of a large central bundle with small ones on either side; all vascular bundles are abaxially situated, with abaxial girders only, parenchyma takes the place of the adaxial sclerenchyma; the bases of the prickles are sunken and are not bulbous; the abaxial epidermal cells are tall and thin-walled. These distinct anatomical features, in combination with the differences in spikelet structure and habitat, suggest that Aniselytron should be generically separated from and not merged with Calamagrostis s. l. Due to the adaxial parenchyma in the midrib which has never been found in Pooideae, Aniselytron might have a relationship with some other subfamily.

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

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    Kerstin Diekmann

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

  20. LES STRATEGIES D’APPRENTISSAGE DU FRANÇAIS LANGUE ÉTRANGÈRE MISES EN PRATIQUE PAR LES APPRENANTS AFIN DE PROMOUVOIR LEURS AUTONOMIES

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    Yasmine ADIB

    2016-12-01

    Full Text Available Ce travail de recherche présente les stratégies d’apprentissage du français langue étrangère et examine les liens entre stratégies et acquisition d’une compétence générale. Cette étude met en relief l’apport majeur des données issues de la psychologie cognitive qui nous renseigne sur les mécanismes qui permettent à l’apprenant d’acquérir, d’intégrer et de réutiliser des connaissances. Aussi, nous expliquons comment les données de la psychologie cognitive nous éclairent sur la nature de l’apprentissage. Le but fondamental de la mise en pratique des stratégies d’apprentissage et de promouvoir l’autonomie de l’apprenant. Il convient de signaler que les stratégies d’apprentissage désignent un ensemble d’opérations mises en œuvre par l’apprenant pour acquérir, intégrer et réutiliser la langue cible. L’apprentissage du français langue étrangère peut être vu comme tout autre processus de traitement de l’information: d’abord, l’apprenant sélectionne et saisit les éléments nouveaux d’information qui lui sont présentés, ensuite, il traite et emmagasine cette information dans sa mémoire. Enfin, il la récupère afin de la réutiliser.LEARNING STRATEGIES OF THE FRENCH FOREIGN LANGUAGE PRACTICED BY LEARNERS TO PROMOTE THEIR AUTONOMYThis research work presents the learning strategies of French foreign language and examines the links between strategies and acquisition of general jurisdiction. We present some definitions and we describe and classify the different learning strategies. We underline the major contribution of data from cognitive psychology that informs us about the mechanisms that allow the learner to acquire, integrate and reuse knowledge. Also, we explain how data from cognitive psychology shed light on the nature of learning. The fundamental purpose of the implementation of learning strategies and promote learner autonomy. It should be noted that learning strategies

  1. Errores, corrección y fosilización en la didáctica de lenguas afines: análisis de errores en la expresión escrita de estudiantes italianos de E/LE

    OpenAIRE

    Sánchez-Iglesias, Jorge J.

    2003-01-01

    [ES]A partir del análisis de los errores cometidos por estudiantes italianos de español – lengua extrajera, nuestro trabajo realiza algunas consideraciones sobre las lenguas afines en términos didácticos y adquisicionales. El trabajo se divide en tres partes. La primera se centra en los problemas del análisis de errores como modelo. Por una parte, consideramos las “criticas epistemológicas”, que surgen de la dialéctica entre la lingüística aplicada y los estudios de adquisición de segun...

  2. Origin of the invasive Arundo donax (Poaceae): a trans-Asian expedition in herbaria.

    Science.gov (United States)

    Hardion, Laurent; Verlaque, Régine; Saltonstall, Kristin; Leriche, Agathe; Vila, Bruno

    2014-09-01

    The hypothesis of an ancient introduction, i.e. archaeophyte origin, is one of the most challenging questions in phylogeography. Arundo donax (Poaceae) is currently considered to be one of the worst invasive species globally, but it has also been widely utilzed by man across Eurasia for millennia. Despite a lack of phylogenetic data, recent literature has often speculated on its introduction to the Mediterranean region. This study tests the hypothesis of its ancient introduction from Asia to the Mediterranean by using plastid DNA sequencing and morphometric analysis on 127 herbarium specimens collected across sub-tropical Eurasia. In addition, a bioclimatic species distribution model calibrated on 1221 Mediterranean localities was used to identify similar ecological niches in Asia. Despite analysis of several plastid DNA hypervariable sites and the identification of 13 haplotypes, A. donax was represented by a single haplotype from the Mediterranean to the Middle East. This haplotype is shared with invasive samples worldwide, and its nearest phylogenetic relatives are located in the Middle East. Morphometric data characterized this invasive clone by a robust morphotype distinguishable from all other Asian samples. The ecological niche modelling designated the southern Caspian Sea, southern Iran and the Indus Valley as the most suitable regions of origin in Asia for the invasive clone of A. donax. Using an integrative approach, an ancient dispersion of this robust, polyploid and non-fruiting clone is hypothesized from the Middle East to the west, leading to its invasion throughout the Mediterranean Basin. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Phylogenomics and taxonomy of Lecomtelleae (Poaceae), an isolated panicoid lineage from Madagascar.

    Science.gov (United States)

    Besnard, Guillaume; Christin, Pascal-Antoine; Malé, Pierre-Jean G; Coissac, Eric; Ralimanana, Hélène; Vorontsova, Maria S

    2013-10-01

    An accurate characterization of biodiversity requires analyses of DNA sequences in addition to classical morphological descriptions. New methods based on high-throughput sequencing may allow investigation of specimens with a large set of genetic markers to infer their evolutionary history. In the grass family, the phylogenetic position of the monotypic genus Lecomtella, a rare bamboo-like endemic from Madagascar, has never been appropriately evaluated. Until now its taxonomic treatment has remained controversial, indicating the need for re-evaluation based on a combination of molecular and morphological data. The phylogenetic position of Lecomtella in Poaceae was evaluated based on sequences from the nuclear and plastid genomes generated by next-generation sequencing (NGS). In addition, a detailed morphological description of L. madagascariensis was produced, and its distribution and habit were investigated in order to assess its conservation status. The complete plastid sequence, a ribosomal DNA unit and fragments of low-copy nuclear genes (phyB and ppc) were obtained. All phylogenetic analyses place Lecomtella as an isolated member of the core panicoids, which last shared a common ancestor with other species >20 million years ago. Although Lecomtella exhibits morphological characters typical of Panicoideae, an unusual combination of traits supports its treatment as a separate group. The study showed that NGS can be used to generate abundant phylogenetic information rapidly, opening new avenues for grass phylogenetics. These data clearly showed that Lecomtella forms an isolated lineage, which, in combination with its morphological peculiarities, justifies its treatment as a separate tribe: Lecomtelleae. New descriptions of the tribe, genus and species are presented with a typification, a distribution map and an IUCN conservation assessment.

  4. Testing four candidate barcoding markers in temperate woody bamboos (Poaceae: Bambusoideae)

    Institute of Scientific and Technical Information of China (English)

    Zhao-Ming CAI; Yu-Xiao ZHANG; Li-Na ZHANG; Lian-Ming GAO; De-Zhu LI

    2012-01-01

    Bambusoideae is an important subfamily of the grass family Poaceae that has considerable economic,ecologic and cultural value.In addition,Bambusoideae species are important constituents of the forest vegetation in China.Because of the paucity of flower-bearing specimens and homoplasies of morphological characters,it is difficult to identify species of Bambusoideae using morphology alone,especially in the case of temperate woody bamboos (i.e.Arundinarieae).To this end,DNA barcoding has shown great potential in identifying species.The present study is the first attempt to test the feasibility of four proposed DNA barcoding markers (matK,rbcL,trnH-psbA,and internal transcribed spacer [ITS]) in identifying 27 species of the temperate woody bamboos.Three plastid markers showed high levels of universality,whereas the universality of ITS was comparatively low.A single plastid marker provided low levels of discrimination success at both the genus and species levels (< 12%).Among the combinations ofplastid markers,the highest discriminatory power was obtained using the combination of rbcL + matK (14.8%).Using a combination of three markers did not increase species discrimination.The nuclear region ITS alone could identify 66.7% of species,although fewer taxa were included in the ITS analyses than in the plastid analyses.When ITS was integrated with a single or combination of plastid markers,the species discriminatory power was significantly improved.We suggest that a combination ofrbcL + ITS,which exhibited the highest species identification power of all combinations in the present study,could be used as a potential DNA barcode for temperate woody bamboos.

  5. Genome Alignment Spanning Major Poaceae Lineages Reveals Heterogeneous Evolutionary Rates and Alters Inferred Dates for Key Evolutionary Events.

    Science.gov (United States)

    Wang, Xiyin; Wang, Jingpeng; Jin, Dianchuan; Guo, Hui; Lee, Tae-Ho; Liu, Tao; Paterson, Andrew H

    2015-06-01

    Multiple comparisons among genomes can clarify their evolution, speciation, and functional innovations. To date, the genome sequences of eight grasses representing the most economically important Poaceae (grass) clades have been published, and their genomic-level comparison is an essential foundation for evolutionary, functional, and translational research. Using a formal and conservative approach, we aligned these genomes. Direct comparison of paralogous gene pairs all duplicated simultaneously reveal striking variation in evolutionary rates among whole genomes, with nucleotide substitution slowest in rice and up to 48% faster in other grasses, adding a new dimension to the value of rice as a grass model. We reconstructed ancestral genome contents for major evolutionary nodes, potentially contributing to understanding the divergence and speciation of grasses. Recent fossil evidence suggests revisions of the estimated dates of key evolutionary events, implying that the pan-grass polyploidization occurred ∼96 million years ago and could not be related to the Cretaceous-Tertiary mass extinction as previously inferred. Adjusted dating to reflect both updated fossil evidence and lineage-specific evolutionary rates suggested that maize subgenome divergence and maize-sorghum divergence were virtually simultaneous, a coincidence that would be explained if polyploidization directly contributed to speciation. This work lays a solid foundation for Poaceae translational genomics. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  6. Relative efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal Samplers for Poaceae and Urticaceae pollen under field conditions.

    Science.gov (United States)

    Peel, Robert G; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-01-01

    In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these differences inter-sampler correction factors may be applied, however for many pollen samplers and pollen taxa such correction factors do not exist and cannot be derived from existing published work. In this study, the relative efficiencies of the Burkard 7-Day Recording Volumetric Spore Trap, the Sampling Technologies Rotorod Model 20, and the Burkard Personal Volumetric Air Sampler were evaluated for Urticaceae and Poaceae pollen under field conditions. The influence of wind speed and relative humidity on these efficiency relationships was also assessed. Data for the two pollen taxa were collected during 2010 and 2011-2012, respectively. The three devices were found to record significantly different concentrations for both pollen taxa, with the exception of the 7-Day and Rotorod samplers for Poaceae pollen. Under the range of conditions present during the study, wind speed was found to only have a significant impact on inter-sampler relationships involving the vertically-orientated Burkard Personal sampler, while no interaction between relative efficiency and relative humidity was observed. Data collected with the three models of sampler should only be compared once the appropriate correction has been made, with wind speed taken into account where appropriate.

  7. Acrapex azumai Sugi (Lepidoptera, Noctuidae) as a possible biological control agent of the invasive weed Imperata cylindrica (L.) Beauv. (Poaceae) in the United States

    Science.gov (United States)

    Lepidopteran larvae were discovered boring in the basal stems of Imperata cylindrica (L.) Beauv. (Poaceae) in Itoshima city, Fukuoka Prefecture, Kyushu, Japan. Adults reared from these larvae were identified as Acrapex azumai Sugi (Lepidoptera: Noctuidae). Sequencing of the CO1 (cytochrome oxidase 1...

  8. Disentangling the effects of feedback structure and climate on Poaceae annual airborne pollen fluctuations and the possible consequences of climate change.

    Science.gov (United States)

    García de León, David; García-Mozo, Herminia; Galán, Carmen; Alcázar, Purificación; Lima, Mauricio; González-Andújar, José L

    2015-10-15

    Pollen allergies are the most common form of respiratory allergic disease in Europe. Most studies have emphasized the role of environmental processes, as the drivers of airborne pollen fluctuations, implicitly considering pollen production as a random walk. This work shows that internal self-regulating processes of the plants (negative feedback) should be included in pollen dynamic systems in order to give a better explanation of the observed pollen temporal patterns. This article proposes a novel methodological approach based on dynamic systems to investigate the interaction between feedback structure of plant populations and climate in shaping long-term airborne Poaceae pollen fluctuations and to quantify the effects of climate change on future airborne pollen concentrations. Long-term historical airborne Poaceae pollen data (30 years) from Cordoba city (Southern Spain) were analyzed. A set of models, combining feedback structure, temperature and actual evapotranspiration effects on airborne Poaceae pollen were built and compared, using a model selection approach. Our results highlight the importance of first-order negative feedback and mean annual maximum temperature in driving airborne Poaceae pollen dynamics. The best model was used to predict the effects of climate change under two standardized scenarios representing contrasting temporal patterns of economic development and CO2 emissions. Our results predict an increase in pollen levels in southern Spain by 2070 ranging from 28.5% to 44.3%. The findings from this study provide a greater understanding of airborne pollen dynamics and how climate change might impact the future evolution of airborne Poaceae pollen concentrations and thus the future evolution of related pollen allergies.

  9. Chloroplast phylogenomic analyses resolve deep-level relationships of an intractable bamboo tribe Arundinarieae (poaceae).

    Science.gov (United States)

    Ma, Peng-Fei; Zhang, Yu-Xiao; Zeng, Chun-Xia; Guo, Zhen-Hua; Li, De-Zhu

    2014-11-01

    The temperate woody bamboos constitute a distinct tribe Arundinarieae (Poaceae: Bambusoideae) with high species diversity. Estimating phylogenetic relationships among the 11 major lineages of Arundinarieae has been particularly difficult, owing to a possible rapid radiation and the extremely low rate of sequence divergence. Here, we explore the use of chloroplast genome sequencing for phylogenetic inference. We sampled 25 species (22 temperate bamboos and 3 outgroups) for the complete genome representing eight major lineages of Arundinarieae in an attempt to resolve backbone relationships. Phylogenetic analyses of coding versus noncoding sequences, and of different regions of the genome (large single copy and small single copy, and inverted repeat regions) yielded no well-supported contradicting topologies but potential incongruence was found between the coding and noncoding sequences. The use of various data partitioning schemes in analysis of the complete sequences resulted in nearly identical topologies and node support values, although the partitioning schemes were decisively different from each other as to the fit to the data. Our full genomic data set substantially increased resolution along the backbone and provided strong support for most relationships despite the very short internodes and long branches in the tree. The inferred relationships were also robust to potential confounding factors (e.g., long-branch attraction) and received support from independent indels in the genome. We then added taxa from the three Arundinarieae lineages that were not included in the full-genome data set; each of these were sampled for more than 50% genome sequences. The resulting trees not only corroborated the reconstructed deep-level relationships but also largely resolved the phylogenetic placements of these three additional lineages. Furthermore, adding 129 additional taxa sampled for only eight chloroplast loci to the combined data set yielded almost identical

  10. Breeding system diversification and evolution in American Poa supersect. Homalopoa (Poaceae: Poeae: Poinae).

    Science.gov (United States)

    Giussani, Liliana M; Gillespie, Lynn J; Scataglini, M Amalia; Negritto, María A; Anton, Ana M; Soreng, Robert J

    2016-08-01

    Poa subgenus Poa supersect. Homalopoa has diversified extensively in the Americas. Over half of the species in the supersection are diclinous; most of these are from the New World, while a few are from South-East Asia. Diclinism in Homalopoa can be divided into three main types: gynomonoecism, gynodioecism and dioecism. Here the sampling of species of New World Homalopoa is expanded to date its origin and diversification in North and South America and examine the evolution and origin of the breeding system diversity. A total of 124 specimens were included in the matrix, of which 89 are species of Poa supersect. Homalopoa sections Acutifoliae, Anthochloa, Brizoides, Dasypoa, Dioicopoa, Dissanthelium, Homalopoa sensu lato (s.l.), Madropoa and Tovarochloa, and the informal Punapoa group. Bayesian and parsimony analyses were conducted on the data sets based on four markers: the nuclear ribosomal internal tanscribed spacer (ITS) and external transcribed spacer (ETS), and plastid trnT-L and trnL-F. Dating analyses were performed on a reduced Poa matrix and enlarged Poaceae outgroup to utilize fossils as calibration points. A relaxed Bayesian molecular clock method was used. Hermaphroditism appears to be pleisiomorphic in the monophyletic Poa supersect. Homalopoa, which is suggested to have originated in Eurasia 8·4-4·2 million years ago (Mya). The ancestor of Poa supersect. Homalopoa radiated throughout the New World in the Late Miocene-Early Pliocene, with major lineages originating during the Pliocene to Pleistocene (5-2 Mya). Breeding systems are linked to geographic areas, showing an evolutionary pattern associated with different habitats. At least three major pathways from hermaphroditism to diclinism are inferred in New World Homalopoa: two leading to dioecism, one via gynodioecism in South America and another directly from hermaphroditism in North America, a result that needs to be checked with a broader sampling of diclinous species in North America. A third

  11. On the genome constitution and evolution of intermediate wheatgrass (Thinopyrum intermedium: Poaceae, Triticeae

    Directory of Open Access Journals (Sweden)

    Paštová Ladislava

    2011-05-01

    Full Text Available Abstract Background The wheat tribe Triticeae (Poaceae is a diverse group of grasses representing a textbook example of reticulate evolution. Apart from globally important grain crops, there are also wild grasses which are of great practical value. Allohexaploid intermediate wheatgrass, Thinopyrum intermedium (2n = 6x = 42, possesses many desirable agronomic traits that make it an invaluable source of genetic material useful in wheat improvement. Although the identification of its genomic components has been the object of considerable investigation, the complete genomic constitution and its potential variability are still being unravelled. To identify the genomic constitution of this allohexaploid, four accessions of intermediate wheatgrass from its native area were analysed by sequencing of chloroplast trnL-F and partial nuclear GBSSI, and genomic in situ hybridization. Results The results confirmed the allopolyploid origin of Thinopyrum intermedium and revealed new aspects in its genomic composition. Genomic heterogeneity suggests a more complex origin of the species than would be expected if it originated through allohexaploidy alone. While Pseudoroegneria is the most probable maternal parent of the accessions analysed, nuclear GBSSI sequences suggested the contribution of distinct lineages corresponding to the following present-day genera: Pseudoroegneria, Dasypyrum, Taeniatherum, Aegilops and Thinopyrum. Two subgenomes of the hexaploid have most probably been contributed by Pseudoroegneria and Dasypyrum, but the identity of the third subgenome remains unresolved satisfactorily. Possibly it is of hybridogenous origin, with contributions from Thinopyrum and Aegilops. Surprising diversity of GBSSI copies corresponding to a Dasypyrum-like progenitor indicates either multiple contributions from different sources close to Dasypyrum and maintenance of divergent copies or the presence of divergent paralogs, or a combination of both. Taeniatherum

  12. Navegando en aguas turbias: La Confederación General de Gremios Marítimos y Afines y su proyección sindical en la coyuntura peronista (1947-1950

    Directory of Open Access Journals (Sweden)

    Gustavo Nicolás Contreras

    2013-12-01

    Full Text Available En 1947, en los albores del primer gobierno peronista, nacía la Confederación General de Gremios Marítimos y Afines (CGGMA. Su importancia, sus particularidades y su impronta en el proceso social y político de aquella época estimularon la reconstrucción histórica de su recorrido, haciendo referencia a algunos hechos que reconocemos relevantes desde un punto de vista atento a ciertas facetas organizativas, sindicales, políticas e ideológicas distintivas del sector. En su análisis serán rescatados varios sucesos significativos en el desarrollo del gremio y serán precisados el programa político-sindical, la ideología y las prácticas expresadas por la CGGMA

  13. Development of microsatellite markers for Fargesia denudata (Poaceae), the staple-food bamboo of the giant panda.

    Science.gov (United States)

    Lv, Yan; Yu, Tao; Lu, Sihai; Tian, Cheng; Li, Junqing; Du, Fang K

    2016-06-01

    There is a need for microsatellite primers to analyze genetic parameters of Fargesia denudata (Poaceae), the staple-food bamboo of the giant panda (Ailuropoda melanoleuca). Using next-generation sequencing technology, we obtained a 75-Mb assembled sequence of F. denudata and identified 182 microsatellites. Primer pairs for 70 candidate microsatellite markers were selected and validated in four individuals, and 42 primer pairs generated reliable amplicons. Fourteen of 16 tested markers were found to be polymorphic in 72 individuals from four F. denudata populations. The number of alleles ranged from two to 19 per locus; the observed and expected heterozygosities ranged from 0 to 1 and from 0 to 0.87, respectively. The transferability of these 16 novel microsatellite markers was validated in five related species. These markers will be useful for examining the genetic diversity, genetic structure, and cloning of F. denudata, the staple-food bamboo of the giant panda, and related bamboo species.

  14. Poaceae from Yanachaga-Chemillén National Park (Oxapampa, Pasco, Perú. Part I: Bambusoideae

    Directory of Open Access Journals (Sweden)

    María I. La-Torre

    2013-06-01

    Full Text Available This work is the first part of biodiversity study of Poaceae family from Yanachaga-Chemillen National Park and surroundings places (10º35´ − 10º10´ S and 75º10´ − 75º45´ W and from 300 to 3800 m. We analysed the material colected for us since 1995 to 1996 and material deposited in the Herbario San Marcos of Museo de Historia Natural and Missouri Botanical Garden. This first part is dedicated to the Bambusoideae biodiversity. A total of seven genera and 23 species have been registered. In the woody bamboos group, genus Chusquea was the mayor species number (seven. The genus Olyra is the most diverse of the herbaceous bamboos with five species. Descriptions of subfamily, genera and keys for genera and species are developed. Ecology, distribution and studied material are indicated.

  15. Plant Responses to Climate Change: The Case Study of Betulaceae and Poaceae Pollen Seasons (Northern Italy, Vignola, Emilia-Romagna

    Directory of Open Access Journals (Sweden)

    Anna Maria Mercuri

    2016-12-01

    Full Text Available Aerobiological data have especially demonstrated that there is correlation between climate warming and the pollination season of plants. This paper focuses on airborne pollen monitoring of Betulaceae and Poaceae, two of the main plant groups with anemophilous pollen and allergenic proprieties in Northern Italy. The aim is to investigate plant responses to temperature variations by considering long-term pollen series. The 15-year aerobiological analysis is reported from the monitoring station of Vignola (located near Modena, in the Emilia-Romagna region that had operated in the years 1990–2004 with a Hirst spore trap. The Yearly Pollen Index calculated for these two botanical families has shown contrasting trends in pollen production and release. These trends were well identifiable but fairly variable, depending on both meteorological variables and anthropogenic causes. Based on recent reference literature, we considered that some oscillations in pollen concentration could have been a main effect of temperature variability reflecting global warming. The duration of pollen seasons of Betulaceae and Poaceae, depending on the different species included in each family, has not unequivocally been determined. Phenological responses were particularly evident in Alnus and especially in Corylus as a general moving up of the end of pollination. The study shows that these trees can be affected by global warming more than other, more tolerant, plants. The research can be a contribution to the understanding of phenological plant responses to climate change and suggests that alder and hazelnut trees have to be taken into high consideration as sensible markers of plant responses to climate change.

  16. Exploring the genome of the salt-marsh Spartina maritima (Poaceae, Chloridoideae) through BAC end sequence analysis.

    Science.gov (United States)

    Ferreira de Carvalho, J; Chelaifa, H; Boutte, J; Poulain, J; Couloux, A; Wincker, P; Bellec, A; Fourment, J; Bergès, H; Salmon, A; Ainouche, M

    2013-12-01

    Spartina species play an important ecological role on salt marshes. Spartina maritima is an Old-World species distributed along the European and North-African Atlantic coasts. This hexaploid species (2n = 6x = 60, 2C = 3,700 Mb) hybridized with different Spartina species introduced from the American coasts, which resulted in the formation of new invasive hybrids and allopolyploids. Thus, S. maritima raises evolutionary and ecological interests. However, genomic information is dramatically lacking in this genus. In an effort to develop genomic resources, we analysed 40,641 high-quality bacterial artificial chromosome-end sequences (BESs), representing 26.7 Mb of the S. maritima genome. BESs were searched for sequence homology against known databases. A fraction of 16.91% of the BESs represents known repeats including a majority of long terminal repeat (LTR) retrotransposons (13.67%). Non-LTR retrotransposons represent 0.75%, DNA transposons 0.99%, whereas small RNA, simple repeats and low-complexity sequences account for 1.38% of the analysed BESs. In addition, 4,285 simple sequence repeats were detected. Using the coding sequence database of Sorghum bicolor, 6,809 BESs found homology accounting for 17.1% of all BESs. Comparative genomics with related genera reveals that the microsynteny is better conserved with S. bicolor compared to other sequenced Poaceae, where 37.6% of the paired matching BESs are correctly orientated on the chromosomes. We did not observe large macrosyntenic rearrangements using the mapping strategy employed. However, some regions appeared to have experienced rearrangements when comparing Spartina to Sorghum and to Oryza. This work represents the first overview of S. maritima genome regarding the respective coding and repetitive components. The syntenic relationships with other grass genomes examined here help clarifying evolution in Poaceae, S. maritima being a part of the poorly-known Chloridoideae sub-family.

  17. Plant Responses to Climate Change: The Case Study of Betulaceae and Poaceae Pollen Seasons (Northern Italy, Vignola, Emilia-Romagna)

    Science.gov (United States)

    Mercuri, Anna Maria; Torri, Paola; Fornaciari, Rita; Florenzano, Assunta

    2016-01-01

    Aerobiological data have especially demonstrated that there is correlation between climate warming and the pollination season of plants. This paper focuses on airborne pollen monitoring of Betulaceae and Poaceae, two of the main plant groups with anemophilous pollen and allergenic proprieties in Northern Italy. The aim is to investigate plant responses to temperature variations by considering long-term pollen series. The 15-year aerobiological analysis is reported from the monitoring station of Vignola (located near Modena, in the Emilia-Romagna region) that had operated in the years 1990–2004 with a Hirst spore trap. The Yearly Pollen Index calculated for these two botanical families has shown contrasting trends in pollen production and release. These trends were well identifiable but fairly variable, depending on both meteorological variables and anthropogenic causes. Based on recent reference literature, we considered that some oscillations in pollen concentration could have been a main effect of temperature variability reflecting global warming. The duration of pollen seasons of Betulaceae and Poaceae, depending on the different species included in each family, has not unequivocally been determined. Phenological responses were particularly evident in Alnus and especially in Corylus as a general moving up of the end of pollination. The study shows that these trees can be affected by global warming more than other, more tolerant, plants. The research can be a contribution to the understanding of phenological plant responses to climate change and suggests that alder and hazelnut trees have to be taken into high consideration as sensible markers of plant responses to climate change. PMID:27929423

  18. Evaluation of pollen production in Bromus catharticus Vahl and Guadua trinii (Nees) Nees ex Rupr. (Poaceae) for interpretation of fossil data

    OpenAIRE

    Jefferson Nunes Radaeski; Soraia Girardi Bauermann

    2016-01-01

    We evaluated pollen production per anther, per flower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae), which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on pollination system. Anthers were macerated and pollen grains were counted in a Neubauer chamber. Pollen morphology was observed using optical and scanning electron microscopy to establish relations...

  19. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of Rubiaceae, Fabaceae and Poaceae plants: A search for new sources of useful alternative antibacterials against MRSA infections.

    Science.gov (United States)

    Sharifi-Rad, M; Iriti, M; Sharifi-Rad, M; Gibbons, S; Sharifi-Rad, J

    2016-08-29

    In this study, we evaluated the effects of the extracts of the leaves of species from the Rubiaceae (Galium aparine L. and Asperula arvensis L.), Fabaceae (Lathyrus aphaca L. and Vicia narbonensis L.) and Poaceae (Digitaria sanguinalis (L.) Scop. and Hordeum murinum L.) plant families on a wide and extensive panel of isolated methicillin-resistant Staphylococcus aureus strains (MRSA). The effects of the methanolic leaf extracts of Rubiaceae, Fabaceae and Poaceae plants on MRSA were evaluated by the disc diffusion assay and the broth dilution method. Among a total of 177 S. aureus isolates, 92 (51.97%) were found to be methicillin-resistant in an antibiogram and this was confirmed by the presence of the mecA gene in polymerase chain reaction method. All MRSA isolates were sensitive to all extracts. There were dose-dependent inhibitions on tested microorganisms for all plant extracts which showed maximum inhibition zones at a concentration of 300 mg/L. L. aphaca, G. aparine and H. murinum exhibited the highest antibacterial activity on the MRSA strains compared to the positive control (P MRSA isolates ranged from 388.4 ± 0.2 mg/L, in D. sanguinalis, to 5.5 ± 0.1 mg/L, in L. aphaca. The methanolic extracts of L. aphaca (Fabaceae), G. aparine (Rubiaceae), and H. murinum (Poaceae) proved to have high antibacterial activity on MRSA isolates, thus representing promising antimicrobial agents in clinical settings.

  20. Micofilas, endófitos fúngicos y alcaloides en poblaciones de Melica stuckertii (Poaceae del Centro de Argentina Mycophyllas, fungal endophytes and alkaloids in populations of Melica stuckertii (Poaceae from central Argentina

    Directory of Open Access Journals (Sweden)

    Cecilia A. Benavente

    2008-12-01

    Full Text Available Los vástagos de Poaceae pueden establecer con Ascomycetes (Balansieae asociaciones simbióticas endofíticas denominadas micofilas. Las gramíneas no pueden sintetizar alcaloides en ausencia del endófito fúngico. Melica stuckertii Hack. es una Poaceae nativa de amplia distribución en el país. El objetivo de este trabajo fue estudiar tres poblaciones de M. stuckertii de San Luis (Argentina, considerando: la presencia y frecuencia de endófitos, la producción de alcaloides en la asociación y el simbionte fúngico. A partir de cariopsis se obtuvieron plántulas axénicas de las que se aisló el simbionte fúngico en medio sólido, siendo cultivado para su determinación taxonómica. Además, las plántulas axénicas se utilizaron para la determinación de alcaloides in planta y el aislamiento de endófito en medio líquido para la posterior detección de alcaloides in fungus. También se examinó la producción de alcaloides «en plantas a campo». Melica stuckertii resultó asociada formando micofilas con una frecuencia de colonización del 100 % en las tres poblaciones estudiadas. Las colonias obtenidas fueron blancoalgodonosas y de crecimiento lento, y el endófito aislado se determinó como Neotyphodium sp. Los alcaloides fueron detectados sólo en la simbiosis (plántulas axénicas y plantas a campo; así, su biosíntesis en M. stuckertii podría ser sinérgica.Poaceae stems are usually associated with Ascomycetes (Balansieae forming symbiotic associations named mycophyllas. Grasses can not produce alkaloids by itself instead they have to be associated to fungal symbiont to yield them. Melica stuckertii is a native and widespread grass. The aims of this work were to study three M. stuckertii population from San Luis province (Argentina taking into account frequency of colonization and alkaloids production. Fungal endophytes were isolated from axenic plantlets obtained from cariopses, and then they were cultured in solid potatoe glucose

  1. Anther and pollen development in some species of Poaceae (Poales Desenvolvimento da antera e do grão de pólen em espécies de Poaceae (Poales

    Directory of Open Access Journals (Sweden)

    AT. Nakamura

    2010-05-01

    Full Text Available Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae, Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae, Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae. The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level.O desenvolvimento da antera e do grão de pólen de Olyra humilis Nees, Sucrea monophylla Soderstr. (Bambusoideae, Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae, Eragrostis solida Nees and Chloris elata Desv. (Chloridoideae foi estudado visando caracterizar embriologicamente essas espécies de subfamílias consideradas basal, intermediária e derivada, respectivamente. As espécies são similares entre si e entre as demais Poaceae. Apresentam os seguintes caracteres: anteras tetrasporangiadas; desenvolvimento da parede da antera do tipo monocotiledôneo, endotécio com espessamento de parede anelar, tapete secretor; microsporogênese sucessiva; tétrades isobilaterais; grãos de

  2. VARIABILIDAD MORFOLÓGICA DE LAS ESPECIES DEL COMPLEJO POA RESINULOSA (POACEAE Y SU RELACIÓN CON LAS ESPECIES DE LA SECCIÓN DIOICOPOA

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    M. Gabriela Fernández Pepi

    2008-01-01

    Full Text Available El complejo Poa resinulosa incluye un grupo de especies conformado por P. calchaquiensis, P. pedersenii y P. resinulosa, de difícil delimitación debido a que las entidades son afines en cuanto a su morfología, aunque presentan distribución disyunta. Para evaluar y analizar a las especies del complejo Poa resinulosa y especies afines al mismo complejo, se midieron 40 caracteres morfológicos y anatómicos en ejemplares de Poa calchaquiensis, P. lanigera, P. pilcomayensis y P. resinulosa. Esos datos se incorporaron a la matriz del conjunto de especies de Poa sección Dioicopoa confeccionada por Giussani (2000, incluyendo también a P. nubensis una nueva especie afín a P. calchaquiensis. Mediante el análisis de componentes principales y pruebas estadísticas, se circunscribió a las especies del complejo Poa resinulosa. Se describió a P. resinulosa como una variedad de P. ligularis, de la que se diferencia por poseer lígula corta, hojas y cañas de menor longitud, menor ancho de la lámina y estomas de menor tamaño. Se presenta una clave para la identificación de Poa ligularis var. resinulosa y taxones afines, y un mapa con la distribución geográfica de ambas variedades de P. ligularis.

  3. La Constitución Política enseñada a alumnos de educación superior no estudiantes de Derecho o ciencias afines: Un reto para la enseñanza

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    Carlos Andrés García Jiménez

    2013-06-01

    Full Text Available La Constitución Política de 1991 ordena el estudio del texto constitucional y el fomento de la participación en todas las instituciones educativas del país.  La enseñanza de la constitución y el avance en compe- tencias ciudadanas es esencial para el desarrollo de los individuos y los Estados.  Es necesario plantear un modelo pedagógico diferente al tradicional en el que se manejan estos temas por personas o estudiantes adscritos a facultades de Derecho o ciencias afines en instituciones de educación superior, el cual deberá ser especialmente diseñado para ciudadanos del común.  El nuevo modelo pedagógico debe buscar corregir las falencias del tradicional y ser efectivo frente al cumplimiento de los objetivos de la asignatura y el desarrollo de competencias ciudadanas como se describe en el texto.

  4. Anatomía ecológica de algunas especies del género Paspalum (Poaceae, Panicoideae, Paniceae

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    Sandra S. Aliscioni

    2000-01-01

    Full Text Available Aliscioni, S. S. 2000. Anatomía ecológica de algunas especies del género Paspalum(Poaceae, Panicoideae, Paniceae. Darwiniana 38(3-4: 187-207.El género Paspalum L. presenta un elevado número de especies, con una amplia variabilidadmorfológica y una extensa distribución geográfica. Sus especies crecen en hábitats sumamente diversos,desde ambientes muy húmedos o acuáticos, a lugares secos de suelos arcillosos o arenosos, muchas vecessalinos. Dada la diversidad de ambientes en los que puede hallarse Paspalum, se estudiaron lascaracterísticas anatómico-foliares presentes en el género con la finalidad de interpretar diferentesestrategias adaptativas en distintas especies. Se presenta una descripción general de la anatomía foliar delgénero y se discuten ciertos caracteres anatómicos, interpretando su posible relación con las condicionesdel hábitat

  5. Development of microsatellite markers for Fargesia denudata (Poaceae), the staple-food bamboo of the giant panda1

    Science.gov (United States)

    Lv, Yan; Yu, Tao; Lu, Sihai; Tian, Cheng; Li, Junqing; Du, Fang K.

    2016-01-01

    Premise of the study: There is a need for microsatellite primers to analyze genetic parameters of Fargesia denudata (Poaceae), the staple-food bamboo of the giant panda (Ailuropoda melanoleuca). Methods and Results: Using next-generation sequencing technology, we obtained a 75-Mb assembled sequence of F. denudata and identified 182 microsatellites. Primer pairs for 70 candidate microsatellite markers were selected and validated in four individuals, and 42 primer pairs generated reliable amplicons. Fourteen of 16 tested markers were found to be polymorphic in 72 individuals from four F. denudata populations. The number of alleles ranged from two to 19 per locus; the observed and expected heterozygosities ranged from 0 to 1 and from 0 to 0.87, respectively. The transferability of these 16 novel microsatellite markers was validated in five related species. Conclusions: These markers will be useful for examining the genetic diversity, genetic structure, and cloning of F. denudata, the staple-food bamboo of the giant panda, and related bamboo species. PMID:27347452

  6. Genetic diversity and spatial correlation patterns unravel the biogeographical history of the European sweet vernal grasses (Anthoxanthum L., Poaceae).

    Science.gov (United States)

    Pimentel, Manuel; Sahuquillo, Elvira; Catalán, Pilar

    2007-08-01

    Different processes have contributed to shaping the present distribution of the European biotas. Up to three different tertiary- to quaternary-time-scale evolutionary scenarios have been proposed to interpret the divergence and genetic structuring of plant species in Europe. In the present study, the Amplified Fragment Length Polymorphisms technique has been used to unravel the species and regional phylogeography of the European sweet vernal grasses (Anthoxanthum L. Poaceae). Forty-six populations belonging to all seven European species of Anthoxanthum and covering a broad geographical and ecological range were selected. Different phylogeography and population genetics diversity and structure estimates indicated a clear divergence of old Messinian Mediterranean lineages, followed by a pre-Pliocene split between Mediterranean annuals and Eurosiberian perennials and a more recent Pleistocene differentiation of Arctic-Alpine, Atlantic and Submediterranean diploid to polyploid landraces. Regional and population correlation tests between geographical and genetic distances allowed to postulate distinct pre- and post-glacial colonization pathways across Europe for the taxa of this widespread genus.

  7. Cytomorphological studies in some members of tribe Paniceae (Poaceae) from district Kangra of Himachal Pradesh (Western Himalayas).

    Science.gov (United States)

    Kaur, H; Kumari, S; Gupta, R C

    2013-01-01

    The present paper deals with cytological studies on the population basis of 21 species belonging to 9 genera of tribe Paniceae of family Poaceae from cytologically unexplored area of Western Himalayas i.e. district Kangra of Himachal Pradesh for the assessment of genetic diversity of grass flora. On world-wide basis, the chromosome counts have been made for the first time for three species such as Brachiaria remota (n = 16), Digitaria granularis (n = 36) and Isachne albens (n = 5). Similarly, on India basis, altogether new records are made for two species such as Echinochloa cruspavonis (n = 27) and Paspalum distichum (2n = 50). A comparison of the different euploid cytotypes studied at present for Digitaria adscendens, D. setigera and Oplismenus compositus revealed significant variations in their morphology, depicting increase in some of the characters of polyploid cytotypes. The course of meiosis has been observed to be normal in all the studied populations with high pollen fertility except for two species such as Paspalum dilatatum and P. distichum marked with abnormal meiosis and reduced pollen fertility.

  8. Growth promotion and an increase in cell wall extensibility by silicon in rice and some other Poaceae seedlings.

    Science.gov (United States)

    Hossain, Mohammad Talim; Mori, Ryuji; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Fujii, Shuhei; Yamamoto, Ryoichi; Hoson, Takayuki

    2002-02-01

    The effect of silicon on organ growth and its mechanisms of action were studied in rice ( Oryza sativa L. cv. Koshihikari), oat ( Avena sativa L. cv. Victory), and wheat ( Triticum aestivum L. cv. Daichino-Minori) seedlings grown in the dark. Applying silicon in the form of silicic acid to these seedlings via culture solution resulted in growth promotion of third (rice) or second (oat and wheat) leaves. The optimal concentration of silicon was 5-10 mM. No growth promotion was observed in early organs, such as coleoptiles or first leaves. In silicon-treated rice third leaves, the epidermal cell length increased, especially in the basal regions, without any effect on the number of cells, showing that silicon promoted cell elongation but not cell division. Silicon also increased the cell wall extensibility significantly in the basal regions of rice third leaves. These results indicate that silicon stimulates growth of rice and some other Poaceae leaves by increasing cell wall extensibility.

  9. Loline Alkaloids: Currencies of Mutualism

    Science.gov (United States)

    Several species of Lolium and other cool-season grasses (Poaceae subfamily Pooideae) tend to harbor symbiotic, seed-transmitted, fungi that enhance their fitness by various means. These fungal endophytes – species of Neotyphodium or Epichloë (Clavicipitaceae) – are known for production of antiherbiv...

  10. Discovery of Linear Cyclotides in Monocot Plant Panicum laxum of Poaceae Family Provides New Insights into Evolution and Distribution of Cyclotides in Plants*

    Science.gov (United States)

    Nguyen, Giang Kien Truc; Lian, Yilong; Pang, Edmund Weng Hou; Nguyen, Phuong Quoc Thuc; Tran, Tuan Dinh; Tam, James P.

    2013-01-01

    Cyclotides are disulfide-rich macrocyclic peptides that display a wide range of bioactivities and represent an important group of plant defense peptide biologics. A few linear variants of cyclotides have recently been identified. They share a high sequence homology with cyclotides but are biosynthetically unable to cyclize from their precursors. All hitherto reported cyclotides and their acyclic variants were isolated from dicot plants of the Rubiaceae, Violaceae, Cucurbitaceae, and recently the Fabaceae and Solanaceae families. Although several cyclotide-like genes in the Poaceae family were known from the data mining of the National Center for Biotechnology Information (NCBI) nucleotide database, their expression at the protein level has yet to be proven. Here, we report the discovery and characterization of nine novel linear cyclotides, designated as panitides L1–9, from the Panicum laxum of the Poaceae family and provide the first evidence of linear cyclotides at the protein level in a monocot plant. Disulfide mapping of panitide L3 showed that it possesses a cystine knot arrangement similar to cyclotides. Several panitides were shown to be active against Escherichia coli and cytotoxic to HeLa cells. They also displayed a high stability against heat and proteolytic degradation. Oxidative folding of the disulfide-reduced panitide L1 showed that it can fold efficiently into its native form. The presence of linear cyclotides in both dicots and monocots suggests their ancient origin and existence before the divergence of these two groups of flowering plants. Moreover, the Poaceae family contains many important food crops, and our discovery may open up new avenues of research using cyclotides and their acyclic variants in crop protection. PMID:23195955

  11. Novedades en Chusquea deficiens (Poaceae, Bambusoideae, Bambuseae, un bambú muy poco conocido del noroeste argentino New findings in Chusquea deficiens (Poaceae, Bambusoideae, Bambuseae, a rare woody bamboo from Northwestern Argentina

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    Carolina Guerreiro

    2011-06-01

    Full Text Available Chusquea deficiens Parodi (Poaceae, Bambusoideae, Bambuseae fue descrita originalmente en 1941 y es conocida solo por el ejemplar tipo y un paratipo. Desde entonces, no se han identificado nuevos ejemplares de esta especie. A través del estudio y la revisión de colecciones de herbarios, se hallaron tres nuevos ejemplares de C. deficiens. Contando con este material, se realizaron preparados histológicos de tallo, hoja caulinar y lámina foliar, los cuales fueron observados y fotografiados con microscopio óptico y electrónico de barrido. Esto permitió describir los caracteres anatómicos foliares y caulinares y seleccionar aquellos de valor taxonómico. Se ilustran caracteres morfológicos y reproductivos de C. deficiens no reconocidos hasta el presente. Asimismo, se pudo ampliar su área de distribución. Se presenta una clave para diferenciar las especies del género Chusquea presentes en el Noroeste Argentino basada en caracteres morfológicos y anatómicos caulinares.Chusquea deficiens Parodi was first described in 1941 and it is known only from the type specimen. Since then, it has not been recollected again. New records of C. deficiens were found in previously undetermined herbarium specimens. With this new material, foliage leaf, culm leaf and culm anatomy were described and illustrated using scanning electron and light microscope. Epidermal and cross section studies were carried out with the purpose of identifying culm and leaf characters of taxonomic value. Morphological and reproductive characters of C. deficiens are illustrated in detail. Furthermore, its geographical distribution is revised and updated. An identification key to the species of Chusquea from Northwestern Argentina based on morphological and culm anatomical characters is presented.

  12. e Ciências Afins (MAST

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    Marcus Granato

    2005-01-01

    Full Text Available MAST is a science and technology museum located in the grounds and architectural complex belonging to the former Observatório Nacional in Rio de Janeiro. This complex, concluded in 1921, comprises of 16 buildings, and was listed by the Artistic and Historic National (1986 and State (1987 Heritage. This complex features three pavilions sheltering the equatorial telescopes, typical examples of Architecture and Engineering buildings for Astronomic purposes. Two of these pavilions, all of which are under the care of MAST, shelter the 21 cm and 32 cm telescopes, plus a third, part of the National Observatory, which houses the 46 cm equatorial telescope. The present study is the result of the work undertaken by MAST to preserve and restore the historical buildings under its responsibility. Thanks to a partnership set up with the Vitae Foundation, it has been possible to develop restoration work covering all aspects of the pavilions (moving metal dome, building, scientific instrument, as well as the area’s museography, with a view to informing visitors about the restoration work undertaken. The project, based on the historical research on the complex, was carried out by a multidisciplinary team over two years. Each stage of the work was comprehensively photographed, including the intervention project design, which was based on architectural surveys and the diagnosis of the complex’s state of repair, plus the restoration per se. This is a groundbreaking initiative in Latin America and will serve as an example for future actions to be taken on historical buildings, especially those built for scientific and technological purposes.

  13. e Ciências Afins (MAST

    Directory of Open Access Journals (Sweden)

    Marcus Granato

    2007-01-01

    Full Text Available MAST is a science and technology museum located on the premises of and within the architectural complex belonging to the former National Observatory of Rio de Janeiro. Soon after the museum was created, the historical heritage existing there – which pertains to a significant period of the history of science in Brazil – was listed by the Brazilian National Heritage Institute (Iphan and the Rio de Janeiro State Cultural Heritage Institute (Inepac in 1986 and 1987, respectively. The listed heritage comprises 16 buildings as well as a collection of scientific instruments and other significant artifacts, including a collection of furniture. Following on from previous interventions on the instruments in the collection and the astronomy domes within the campus, the restoration and rehabilitation of significant parts of the listed heritage under MAST’s responsibility were made possible through a partnership with VITAE Foundation. The project was carried out by a multidisciplinary team and based on historical research into the meridian circle and its shelter over a period of three years. It was accompanied by an exhaustive photographic recording of each stage of the project, including a diagnosis of the instrument is upkeep and its restoration, the rehabilitation of the pavilion, and the replacement of the instrument to its original position, as well as a description of the museum to provide the visitors with information about the restoration work carried out. It should be noted that the restored instrument was at great risk of being lost, as it had been left disassembled since the 1960s, and the top part of the dome that sheltered it had been demolished in the 1980s, leaving just a vestibule and the base of the dome, part of which was in danger of collapsing. The rationale behind this intervention was not to put the instrument back in working order, but to allow it to be viewed and understood by the public within the museum space that was created. The project highlighted the object’s power of communication. As for the dome, a shelter was built for the instrument using a metal cover similar to the original in volume and appearance, but with a different function, i.e. it is no longer designed for astronomical investigation, but rather to protect the exhibition space and merge harmoniously with the rest of the listed architectural complex.

  14. Anatomía y etnobotánica de las especies medicinales de monocotiledóneas de la Estepa Pampeana de Argentina: Poaceae

    OpenAIRE

    Ana M Arambarri; Néstor D. Bayón

    1998-01-01

    La estepa pampeana (este de la Argentina, Uruguay y sur de Río Grande do Sul, en el Brasil) posee 34 especies de Monocotiledóneas (Angiospermas) con propiedades medicinales. En el presente trabajo se ofrece el estudio de 11 especies pertenecientes a la familia Poaceae (= Gramineae). Para cada una de las especies se brindan los principales sinónimos, nombres vulgares, descripción, análisis histológico de las partes utilizadas, mapa de distribución en la estepa pampeana, ilustración y refere...

  15. Helicoverpa zea (Lepidoptera: Noctuidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Responses to Sorghum bicolor (Poales: Poaceae) Tissues From Lowered Lignin Lines.

    Science.gov (United States)

    Dowd, Patrick F; Sattler, Scott E

    2015-01-01

    The presence of lignin within biomass impedes the production of liquid fuels. Plants with altered lignin content and composition are more amenable to lignocellulosic conversion to ethanol and other biofuels but may be more susceptible to insect damage where lignin is an important resistance factor. However, reduced lignin lines of switchgrasses still retained insect resistance in prior studies. Therefore, we hypothesized that sorghum lines with lowered lignin content will also retain insect resistance. Sorghum excised leaves and stalk pith Sorghum bicolor (L.) Moench (Poales: Poaceae) from near isogenic brown midrib (bmr) 6 and 12 mutants lines, which have lowered lignin content and increased lignocellulosic ethanol conversion efficiency, were examined for insect resistance relative to wild-type (normal BTx623). Greenhouse and growth chamber grown plant tissues were fed to first-instar larvae of corn earworms, Helicoverpa zea (Boddie) and fall armyworms Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), two sorghum major pests. Younger bmr leaves had significantly greater feeding damage in some assays than wild-type leaves, but older bmr6 leaves generally had significantly less damage than wild-type leaves. Caterpillars feeding on the bmr6 leaves often weighed significantly less than those feeding on wild-type leaves, especially in the S. frugiperda assays. Larvae fed the pith from bmr stalks had significantly higher mortality compared with those larvae fed on wild-type pith, which suggested that bmr pith was more toxic. Thus, reducing lignin content or changing subunit composition of bioenergy grasses does not necessarily increase their susceptibility to insects and may result in increased resistance, which would contribute to sustainable production.

  16. Helicoverpa zea (Lepidoptera: Noctuidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Responses to Sorghum bicolor (Poales: Poaceae) Tissues From Lowered Lignin Lines

    Science.gov (United States)

    Dowd, Patrick F.; Sattler, Scott E.

    2015-01-01

    The presence of lignin within biomass impedes the production of liquid fuels. Plants with altered lignin content and composition are more amenable to lignocellulosic conversion to ethanol and other biofuels but may be more susceptible to insect damage where lignin is an important resistance factor. However, reduced lignin lines of switchgrasses still retained insect resistance in prior studies. Therefore, we hypothesized that sorghum lines with lowered lignin content will also retain insect resistance. Sorghum excised leaves and stalk pith Sorghum bicolor (L.) Moench (Poales: Poaceae) from near isogenic brown midrib (bmr) 6 and 12 mutants lines, which have lowered lignin content and increased lignocellulosic ethanol conversion efficiency, were examined for insect resistance relative to wild-type (normal BTx623). Greenhouse and growth chamber grown plant tissues were fed to first-instar larvae of corn earworms, Helicoverpa zea (Boddie) and fall armyworms Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), two sorghum major pests. Younger bmr leaves had significantly greater feeding damage in some assays than wild-type leaves, but older bmr6 leaves generally had significantly less damage than wild-type leaves. Caterpillars feeding on the bmr6 leaves often weighed significantly less than those feeding on wild-type leaves, especially in the S. frugiperda assays. Larvae fed the pith from bmr stalks had significantly higher mortality compared with those larvae fed on wild-type pith, which suggested that bmr pith was more toxic. Thus, reducing lignin content or changing subunit composition of bioenergy grasses does not necessarily increase their susceptibility to insects and may result in increased resistance, which would contribute to sustainable production. PMID:25601946

  17. Species delimitation in plants using the Qinghai–Tibet Plateau endemic Orinus (Poaceae: Tridentinae) as an example

    Science.gov (United States)

    Su, Xu; Wu, Guili; Li, Lili; Liu, Jianquan

    2015-01-01

    Background and Aims Accurate identification of species is essential for the majority of biological studies. However, defining species objectively and consistently remains a challenge, especially for plants distributed in remote regions where there is often a lack of sufficient previous specimens. In this study, multiple approaches and lines of evidence were used to determine species boundaries for plants occurring in the Qinghai–Tibet Plateau, using the genus Orinus (Poaceae) as a model system for an integrative approach to delimiting species. Methods A total of 786 individuals from 102 populations of six previously recognized species were collected for niche, morphological and genetic analyses. Three plastid DNA regions (matK, rbcL and trnH-psbA) and one nuclear DNA region [internal transcribed space (ITS)] were sequenced. Key Results Whereas six species had been previously recognized, statistical analyses based on character variation, molecular data and niche differentiation identified only two well-delimited clusters, together with a third possibly originating from relatively recent hybridization between, or historical introgression from, the other two. Conclusions Based on a principle of integrative species delimitation to reconcile different sources of data, the results provide compelling evidence that the six previously recognized species of the genus Orinus that were examined should be reduced to two, with new circumscriptions, and a third, identified in this study, should be described as a new species. This empirical study highlights the value of applying genetic differentiation, morphometric statistics and ecological niche modelling in an integrative approach to re-circumscribing species boundaries. The results produce relatively objective, operational and unbiased taxonomic classifications of plants occurring in remote regions. PMID:25987712

  18. Species delimitation in plants using the Qinghai-Tibet Plateau endemic Orinus (Poaceae: Tridentinae) as an example.

    Science.gov (United States)

    Su, Xu; Wu, Guili; Li, Lili; Liu, Jianquan

    2015-07-01

    Accurate identification of species is essential for the majority of biological studies. However, defining species objectively and consistently remains a challenge, especially for plants distributed in remote regions where there is often a lack of sufficient previous specimens. In this study, multiple approaches and lines of evidence were used to determine species boundaries for plants occurring in the Qinghai-Tibet Plateau, using the genus Orinus (Poaceae) as a model system for an integrative approach to delimiting species. A total of 786 individuals from 102 populations of six previously recognized species were collected for niche, morphological and genetic analyses. Three plastid DNA regions (matK, rbcL and trnH-psbA) and one nuclear DNA region [internal transcribed space (ITS)] were sequenced. Whereas six species had been previously recognized, statistical analyses based on character variation, molecular data and niche differentiation identified only two well-delimited clusters, together with a third possibly originating from relatively recent hybridization between, or historical introgression from, the other two. Based on a principle of integrative species delimitation to reconcile different sources of data, the results provide compelling evidence that the six previously recognized species of the genus Orinus that were examined should be reduced to two, with new circumscriptions, and a third, identified in this study, should be described as a new species. This empirical study highlights the value of applying genetic differentiation, morphometric statistics and ecological niche modelling in an integrative approach to re-circumscribing species boundaries. The results produce relatively objective, operational and unbiased taxonomic classifications of plants occurring in remote regions. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Expression and characterization of a recombinant psychrophilic Cu/Zn superoxide dismutase from Deschampsia antarctica E. Desv. [Poaceae].

    Science.gov (United States)

    Rojas-Contreras, Juan A; de la Rosa, Ana P Barba; De León-Rodríguez, Antonio

    2015-04-01

    We present here the structural modeling and biochemical characterization of a recombinant superoxide dismutase (SOD) from Deschampsia antarctica E. Desv. [Poaceae] produced in Escherichia coli. The recombinant protein was purified by affinity chromatography nickel-nitrilotriacetic acid (Ni-NTA), and its identity was demonstrated by immunoblotting and inhibition by H2O2 and KCN. Inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis confirmed the presence of Cu and Zn. Modeling of the D. antarctica Cu/Zn-SOD (DaSOD) amino acid sequence using the SWISS-MODEL and 2Q2L_B monomer of the psychrophilic Cu/Zu-SOD from Potentilla atrosanguinea (PaSOD) as template produced a structure similar to that of the typical eukaryotic Cu/Zn-SODs. Activity assays using the p-nitro blue tetrazolium chloride (NBT) solution method showed that the purified DaSOD had a specific activity of 5818 U/mg at 25 °C and pH 7.2 and that it was active in a pH interval of 5-8 and a temperature interval of 0-40 °C. Furthermore, DaSOD was still active at -20 °C as observed by a zymogram assay. We found 100 % activity when it was heated at 80 °C for 60 min, indicating a high thermostability. DaSOD properties suggest that this enzyme could be useful for preventing the oxidation of refrigerated or frozen foods, as well as in the preparation of cosmetic and pharmaceutical products.

  20. Linkage Maps of a Mediterranean × Continental Tall Fescue Population and their Comparative Analysis with Other Poaceae Species

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    Ryan Dierking

    2015-03-01

    Full Text Available Temperate grasses belonging to the complex are important throughout the world in pasture and grassland agriculture. Tall fescue ( Schreb. is the predominant species in the United States, covering approximately 15 million ha. Tall fescue has distinctive morphotypes, two of which are Continental (summer active and Mediterranean (summer semidormant. This is the first report of a linkage map created for Mediterranean tall fescue, while updating the Continental map with additional simple sequence repeat and sequence-tagged site markers. Additionally, this is the first time that diversity arrays technology (DArT markers were used in the construction of a tall fescue map. The male parent (Continental, R43-64, map consisted of 594 markers arranged in 22 linkage groups (LGs and covered a total of 1577 cM. The female parent (Mediterranean, 103-2, map was shorter (1258 cM and consisted of only 208 markers arranged in 29 LGs. Marker densities for R43-64 and 103-2 were 2.65 and 6.08 cM per marker, respectively. When compared with the other Poaceae species, meadow fescue ( Huds., annual ryegrass ( Lam., perennial ryegrass ( L., (L. Beauv., and barley ( L., a total of 171 and 98 orthologous or homologous sequences, identified by DArT analysis, were identified in R43-64 and 103-2, respectively. By using genomic in situ hybridization, we aimed to identify potential progenitors of both morphotypes. However, no clear conclusion on genomic constitution was reached. These maps will aid in the search for quantitative trait loci of various traits as well as help define and distinguish genetic differences between the two morphotypes.

  1. Phylogenetic analysis of Saccharum s.l. (Poaceae; Andropogoneae), with emphasis on the circumscription of the South American species.

    Science.gov (United States)

    Welker, Cassiano A D; Souza-Chies, Tatiana T; Longhi-Wagner, Hilda M; Peichoto, Myriam Carolina; McKain, Michael R; Kellogg, Elizabeth A

    2015-02-01

    Polyploidy and reticulate evolution are often a complication for discovering phylogenetic relationships between genera and species. Despite the huge economic importance of sugarcane (Saccharum officinarum-Poaceae, Andropogoneae), the limits of the genus Saccharum and its species are complex and largely unresolved, involving both polyploidy and reticulate evolution. This study aimed to assess the phylogenetic relationships of Saccharum s.l., including Erianthus and Tripidium, as well as investigate the taxonomic circumscription of the South American species of the genus. Molecular cloning and sequencing of five regions of four low-copy nuclear loci were performed, including Aberrant panicle organization1 (apo1), Dwarf8 (d8), two exons of Erect panicle2 (ep2-ex7 and ep2-ex8), and Retarded palea1 (rep1). Concatenated trees were reconstructed using Maximum Parsimony, Maximum Likelihood, and Bayesian Inference analyses. The allopolyploid origin of Saccharum was demonstrated using evidence from nuclear genes. The samples of Saccharum s.l. grouped in two distinct clades, with S. arundinaceum and S. ravennae (= Tripidium, or Erianthus sect. Ripidium) apart from all other species analyzed of the genus. Saccharum angustifolium, S. asperum, and S. villosum correspond to distinct clades (different species). The plants with intermediate morphology between S. angustifolium and S. villosum presented a pattern of paralogues consistent with a hybrid origin. Saccharum s.l. is polyphyletic and Tripidium should be recognized as a distinct genus. However, no strong evidence was found to support the segregation of Erianthus. The taxonomic circumscription of the South American species of the genus was resolved and the occurrence of natural hybrids was documented. Better understanding of the phylogenetic relationships of Saccharum and relatives may be useful for sugarcane breeders to identify potential taxa for interspecific and intergeneric crosses in the genetic improvement of sugarcane

  2. Evolutionary and Taxonomic Implications of Variation in Nuclear Genome Size: Lesson from the Grass Genus Anthoxanthum (Poaceae).

    Science.gov (United States)

    Chumová, Zuzana; Krejčíková, Jana; Mandáková, Terezie; Suda, Jan; Trávníček, Pavel

    2015-01-01

    The genus Anthoxanthum (sweet vernal grass, Poaceae) represents a taxonomically intricate polyploid complex with large phenotypic variation and its evolutionary relationships still poorly resolved. In order to get insight into the geographic distribution of ploidy levels and assess the taxonomic value of genome size data, we determined C- and Cx-values in 628 plants representing all currently recognized European species collected from 197 populations in 29 European countries. The flow cytometric estimates were supplemented by conventional chromosome counts. In addition to diploids, we found two low (rare 3x and common 4x) and one high (~16x-18x) polyploid levels. Mean holoploid genome sizes ranged from 5.52 pg in diploid A. alpinum to 44.75 pg in highly polyploid A. amarum, while the size of monoploid genomes ranged from 2.75 pg in tetraploid A. alpinum to 9.19 pg in diploid A. gracile. In contrast to Central and Northern Europe, which harboured only limited cytological variation, a much more complex pattern of genome sizes was revealed in the Mediterranean, particularly in Corsica. Eight taxonomic groups that partly corresponded to traditionally recognized species were delimited based on genome size values and phenotypic variation. Whereas our data supported the merger of A. aristatum and A. ovatum, eastern Mediterranean populations traditionally referred to as diploid A. odoratum were shown to be cytologically distinct, and may represent a new taxon. Autopolyploid origin was suggested for 4x A. alpinum. In contrast, 4x A. odoratum seems to be an allopolyploid, based on the amounts of nuclear DNA. Intraspecific variation in genome size was observed in all recognized species, the most striking example being the A. aristatum/ovatum complex. Altogether, our study showed that genome size can be a useful taxonomic marker in Anthoxathum to not only guide taxonomic decisions but also help resolve evolutionary relationships in this challenging grass genus.

  3. Evaluation of pollen production in Bromus catharticus Vahl and Guadua trinii (Nees Nees ex Rupr. (Poaceae for interpretation of fossil data

    Directory of Open Access Journals (Sweden)

    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available We evaluated pollen production per anther, per flower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae, which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on pollination system. Anthers were macerated and pollen grains were counted in a Neubauer chamber. Pollen morphology was observed using optical and scanning electron microscopy to establish relationships between pollen grain production and morphology. The anemophilous species Bromus catharticus (2,556,000 pollen grains/spikelet has twice the pollen production per anther and per spikelet compared to Guadua trinii (1,716,000 pollen grains/spikelet, a species that requires biotic assistance for pollination. Pollen grain size is inversely proportional to production. Microechinate ornamentation, which is not expected to occur in anemophilous species, was observed on pollen of both taxa. Our results indicate that the frequency of forest Poaceae in the quaternary records may be underestimated while frequency of grassland taxa may be overestimated, leading to misrepresentation of the respective flora in this period.

  4. Large-scale bioinformatic analysis of the regulation of the disease resistance NBS gene family by microRNAs in Poaceae.

    Science.gov (United States)

    Habachi-Houimli, Yosra; Khalfallah, Yosra; Makni, Hanem; Makni, Mohamed; Bouktila, Dhia

    2016-01-01

    In the present study, we have screened 71, 713, 525, 119 and 241 mature miRNA variants from Hordeum vulgare, Oryza sativa, Brachypodium distachyon, Triticum aestivum, and Sorghum bicolor, respectively, and classified them with respect to their conservation status and expression levels. These Poaceae non-redundant miRNA species (1,669) were distributed over a total of 625 MIR families, among which only 54 were conserved across two or more plant species, confirming the relatively recent evolutionary differentiation of miRNAs in grasses. On the other hand, we have used 257 H. vulgare, 286T. aestivum, 119 B. distachyon, 269 O. sativa, and 139 S. bicolor NBS domains, which were either mined directly from the annotated proteomes, or predicted from whole genome sequence assemblies. The hybridization potential between miRNAs and their putative NBS genes targets was analyzed, revealing that at least 454 NBS genes from all five Poaceae were potentially regulated by 265 distinct miRNA species, most of them expressed in leaves and predominantly co-expressed in additional tissues. Based on gene ontology, we could assign these probable miRNA target genes to 16 functional groups, among which three conferring resistance to bacteria (Rpm1, Xa1 and Rps2), and 13 groups of resistance to fungi (Rpp8,13, Rp3, Tsn1, Lr10, Rps1-k-1, Pm3, Rpg5, and MLA1,6,10,12,13). The results of the present analysis provide a large-scale platform for a better understanding of biological control strategies of disease resistance genes in Poaceae, and will serve as an important starting point for enhancing crop disease resistance improvement by means of transgenic lines with artificial miRNAs. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  5. The large-scale investigation of gene expression in Leymus chinensis stigmas provides a valuable resource for understanding the mechanisms of poaceae self-incompatibility.

    Science.gov (United States)

    Zhou, Qingyuan; Jia, Junting; Huang, Xing; Yan, Xueqing; Cheng, Liqin; Chen, Shuangyan; Li, Xiaoxia; Peng, Xianjun; Liu, Gongshe

    2014-05-26

    Many Poaceae species show a gametophytic self-incompatibility (GSI) system, which is controlled by at least two independent and multiallelic loci, S and Z. Until currently, the gene products for S and Z were unknown. Grass SI plant stigmas discriminate between pollen grains that land on its surface and support compatible pollen tube growth and penetration into the stigma, whereas recognizing incompatible pollen and thus inhibiting pollination behaviors. Leymus chinensis (Trin.) Tzvel. (sheepgrass) is a Poaceae SI species. A comprehensive analysis of sheepgrass stigma transcriptome may provide valuable information for understanding the mechanism of pollen-stigma interactions and grass SI. The transcript abundance profiles of mature stigmas, mature ovaries and leaves were examined using high-throughput next generation sequencing technology. A comparative transcriptomic analysis of these tissues identified 1,025 specifically or preferentially expressed genes in sheepgrass stigmas. These genes contained a significant proportion of genes predicted to function in cell-cell communication and signal transduction. We identified 111 putative transcription factors (TFs) genes and the most abundant groups were MYB, C2H2, C3H, FAR1, MADS. Comparative analysis of the sheepgrass, rice and Arabidopsis stigma-specific or preferential datasets showed broad similarities and some differences in the proportion of genes in the Gene Ontology (GO) functional categories. Potential SI candidate genes identified in other grasses were also detected in the sheepgrass stigma-specific or preferential dataset. Quantitative real-time PCR experiments validated the expression pattern of stigma preferential genes including homologous grass SI candidate genes. This study represents the first large-scale investigation of gene expression in the stigmas of an SI grass species. We uncovered many notable genes that are potentially involved in pollen-stigma interactions and SI mechanisms, including genes

  6. Simple and efficient method for isolating cDNA fragments of lea3 genes with potential for wide application in the grasses (Poaceae).

    Science.gov (United States)

    Yu, L; Wu, X; Tang, X; Yan, B

    2010-07-06

    cDNA fragments of lea3 genes with a high GC content (from 68 to 77%) were found in several Poaceae, including Sorghum vulgare, Saccharum officinarum, Oryza officinalis, Oryza meyeriana, Ampelocalamus calcareus, Cynodon dactylon, and Zizania latifoli. They were successfully isolated by means of optimal experimental parameters, which included dimethyl sulfoxide as additive and degenerate primers "AGETKAS" and "AGKDKTG", and their sequences were analyzed. Compared to the method of isolating genes by screening of a cDNA library using abscisic acid- and other stress-responsive cDNA clones, which is time-consuming and costly, this method is relatively easy and inexpensive. Using this new method, many new homologue lea3 genes were rapidly determined.

  7. 海南省禾本科药用植物资源概况%Medicinal Plant Resources of Poaceae in Hainan Province

    Institute of Scientific and Technical Information of China (English)

    王建荣; 邓必玉; 李海燕; 王祝年; 黎明; 虞道耿

    2010-01-01

    通过查阅大量文献和实地调查,整理出海南省有禾本科(Poaceae)药用植物资源48属,87种(包括变种).其中筋竹属(Bambusa Schreber)药用植物最多,有9种.海南省禾本科药用植物按药用部位分,全草类最多;按药用功效分,清热类最多.同时还分析了海南省禾本科药用植物资源现状,并提出合理开发利用和保护的建议.

  8. Naturaleza jurídica del consejo profesional nacional de ingeniería –COPNIA- y el ejercicio de la inspección y vigilancia de la ingeniería, sus profesiones afines y sus profesiones auxiliares a la luz de la Constitución Política de 1991

    OpenAIRE

    Baquero Rozo, César Efrén

    2015-01-01

    Al no existir norma positiva que defina la naturaleza jurídica del Consejo Profesional Nacional de Ingeniería –COPNIA-, el presente trabajo propone que esta entidad pública es un Órgano Autónomo e Independiente en virtud de lo establecido en el artículo 113 de la Constitución Política, que ejerce función administrativa para el cumplimiento de su misión, la inspección vigilancia y control de la ingeniería, profesiones afines y profesiones auxiliares, mediante la potestad sancionadora ...

  9. Potential of copper-tolerant grasses to implement phytostabilisation strategies on polluted soils in South D. R. Congo : Poaceae candidates for phytostabilisation.

    Science.gov (United States)

    Boisson, Sylvain; Le Stradic, Soizig; Collignon, Julien; Séleck, Maxime; Malaisse, François; Ngoy Shutcha, Mylor; Faucon, Michel-Pierre; Mahy, Grégory

    2016-07-01

    Phytostabilisation (i.e. using plants to immobilise contaminants) represents a well-known technology to hamper heavy metal spread across landscapes. Southeastern D.R. Congo, Microchloa altera, a tolerant grass from the copper hills, was recently identified as a candidate species to stabilise copper in the soil. More than 50 grasses compose this flora, which may be studied to implement phytostabilisation strategies. However, little is known about their phenology, tolerance, reproductive strategy or demography. The present study aims to characterize the Poaceae that may be used in phytostabilisation purposes based on the following criteria: their ecological distribution, seed production at two times, abundance, soil coverage and the germination percentage of their seeds. We selected seven perennial Poaceae that occur on the copper hills. Their ecological distributions (i.e. species response curves) have been modelled along copper or cobalt gradients with generalised additive models using logic link based on 172 presence-absence samples on three sites. For other variables, a total of 69 quadrats (1 m(2)) were randomly placed across three sites and habitats. For each species, we compared the number of inflorescence-bearing stems (IBS) by plot, the percentage of cover, the number of seeds by IBS and the estimated number of seeds by plot between sites and habitat. Three species (Andropogon schirensis, Eragrostis racemosa and Loudetia simplex) were very interesting for phytostabilisation programs. They produced a large quantity of seeds and had the highest percentage of cover. However, A. schirensis and L. simplex presented significant variations in the number of seeds and the percentage of cover according to site.

  10. A plastome primer set for comprehensive quantitative real time RT-PCR analysis of Zea mays: a starter primer set for other Poaceae species

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    Dunn Sade N

    2008-06-01

    Full Text Available Abstract Background Quantitative Real Time RT-PCR (q2(RTPCR is a maturing technique which gives researchers the ability to quantify and compare very small amounts of nucleic acids. Primer design and optimization is an essential yet time consuming aspect of using q2(RTPCR. In this paper we describe the design and empirical optimization of primers to amplify and quantify plastid RNAs from Zea mays that are robust enough to use with other closely related species. Results Primers were designed and successfully optimized for 57 of the 104 reported genes in the maize plastome plus two nuclear genes. All 59 primer pairs produced single amplicons after end-point reverse transcriptase polymerase chain reactions (RT-PCR as visualized on agarose gels and subsequently verified by q2(RTPCR. Primer pairs were divided into several categories based on the optimization requirements or the uniqueness of the target gene. An in silico test suggested the majority of the primer sets should work with other members of the Poaceae family. An in vitro test of the primer set on two unsequenced species (Panicum virgatum and Miscanthus sinensis supported this assumption by successfully producing single amplicons for each primer pair. Conclusion Due to the highly conserved chloroplast genome in plant families it is possible to utilize primer pairs designed against one genomic sequence to detect the presence and abundance of plastid genes or transcripts from genomes that have yet to be sequenced. Analysis of steady state transcription of vital system genes is a necessary requirement to comprehensively elucidate gene expression in any organism. The primer pairs reported in this paper were designed for q2(RTPCR of maize chloroplast genes but should be useful for other members of the Poaceae family. Both in silico and in vitro data are presented to support this assumption.

  11. Forecasting of the selected features of Poaceae (R. Br.) Barnh., Artemisia L. and Ambrosia L. pollen season in Szczecin, north-western Poland, using Gumbel's distribution.

    Science.gov (United States)

    Puc, Małgorzata; Wolski, Tomasz

    2013-01-01

    The allergenic pollen content of the atmosphere varies according to climate, biogeography and vegetation. Minimisation of the pollen allergy symptoms is related to the possibility of avoidance of large doses of the allergen. Measurements performed in Szczecin over a period of 13 years (2000-2012 inclusive) permitted prediction of theoretical maximum concentrations of pollen grains and their probability for the pollen season of Poaceae, Artemisia and Ambrosia. Moreover, the probabilities were determined of a given date as the beginning of the pollen season, the date of the maximum pollen count, Seasonal Pollen Index value and the number of days with pollen count above threshold values. Aerobiological monitoring was conducted using a Hirst volumetric trap (Lanzoni VPPS). Linear trend with determination coefficient (R(2)) was calculated. Model for long-term forecasting was performed by the method based on Gumbel's distribution. A statistically significant negative correlation was determined between the duration of pollen season of Poaceae and Artemisia and the Seasonal Pollen Index value. Seasonal, total pollen counts of Artemisia and Ambrosia showed a strong and statistically significant decreasing tendency. On the basis of Gumbel's distribution, a model was proposed for Szczecin, allowing prediction of the probabilities of the maximum pollen count values that can appear once in e.g. 5, 10 or 100 years. Short pollen seasons are characterised by a higher intensity of pollination than long ones. Prediction of the maximum pollen count values, dates of the pollen season beginning, and the number of days with pollen count above the threshold, on the basis of Gumbel's distribution, is expected to lead to improvement in the prophylaxis and therapy of persons allergic to pollen.

  12. [b][/b]Relative efficiencies of the Burkard 7-Day, Rotorod and Burkard Personal samplers for Poaceae and Urticaceae pollen under field conditions

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    Robert Peel

    2014-11-01

    Full Text Available [b]Introduction[/b]. In aerobiological studies it is often necessary to compare concentration data recorded with different models of sampling instrument. Sampler efficiency typically varies from device to device, and depends on the target aerosol and local atmospheric conditions. To account for these differences inter-sampler correction factors may be applied, however for many pollen samplers and pollen taxa such correction factors do not exist and cannot be derived from existing published work. [b]Materials and methods.[/b] In this study, the relative efficiencies of the Burkard 7-Day Recording Volumetric Spore Trap, the Sampling Technologies Rotorod Model 20, and the Burkard Personal Volumetric Air Sampler were evaluated for Urticaceae and Poaceae pollen under field conditions. The influence of wind speed and relative humidity on these efficiency relationships was also assessed. Data for the two pollen taxa were collected during 2010 and 2011–2012, respectively. [b]Results[/b]. The three devices were found to record significantly different concentrations for both pollen taxa, with the exception of the 7-Day and Rotorod samplers for Poaceae pollen. Under the range of conditions present during the study, wind speed was found to only have a significant impact on inter-sampler relationships involving the vertically-orientated Burkard Personal sampler, while no interaction between relative efficiency and relative humidity was observed. [b]Conclusions[/b]. Data collected with the three models of sampler should only be compared once the appropriate correction has been made, with wind speed taken into account where appropriate.

  13. Geographical Distribution of Avena L. (Poaceae)%禾本科燕麦属植物的地理分布

    Institute of Scientific and Technical Information of China (English)

    林磊; 刘青

    2015-01-01

    The geographical distribution of Avena L. (Aveneae, Poaceae) was studied by ifeld investigation and reviewing specimens and literature. The results showed that 29 species in Avena were distributed in Europe, Mediterranean, Northern Africa, Western Asia, Eastern Asia, and the Americas. In China, four species of Avena distribute in high altitude areas in the northern, northwestern, and southwestern provinces. Seven sections are delimited in Avena, including sect. Avenotrichon (Holub) Baum, sect. Ventricosa Baum, sect. Agraria Baum, sect. Tenuicarpa Baum, sect. Ethiopica Baum, sect. Pachycarpa Baum, and sect. Avena. The sect. Ethiopica occurs in Ethiopia, Saudi Arabia, and Yemen, and the remaining six sections occur in Mediterranean, Southwestern Europe, Northwestern Africa, Western Asia, Eastern Asia, and the Americas. The results suggest that the Mediterranean, Northwestern Africa, and Western Asia are the distribution centers and diversiifcation centers of Avena, while the origin center of Avena needs to be further studied.%为探讨燕麦属(Avena L.)植物的地理分布,通过野外调查及查阅标本和文献资料,对燕麦属植物的地理分布进行整理和研究。结果表明,燕麦属植物约有29种,主要分布在欧洲、地中海地区、北非、西亚、东亚和美洲。中国有4种,分布于华北、西北、西南各省(区)的高海拔地区。燕麦属下分7个组,分别是多年生燕麦组[sect. Avenotrichon (Holub) Baum]、偏凸燕麦组(sect. Ventricosa Baum)、耕地燕麦组(sect. Agraria Baum)、软果燕麦组(sect. Tenuicarpa Baum)、埃塞俄比亚燕麦组(sect. Ethiopica Baum)、厚果燕麦组(sect. Pachycarpa Baum)和真燕麦组(sect. Avena)。其中,埃塞俄比亚燕麦组分布在埃塞俄比亚、沙特阿拉伯、也门,其他6个组分布在欧洲、地中海、西北非洲、西亚、东亚和美洲地区。地中海、西北非洲、西亚地区分布有除埃塞俄比亚燕麦组之外的所有6

  14. Geographical Distribution of Sorghum Moench (Poaceae)%高粱属植物的地理分布

    Institute of Scientific and Technical Information of China (English)

    刘欢; 曾飞燕; 刘青

    2014-01-01

    为探讨高粱属(Sorghum Moench)的系统发育关系,通过野外调查及查阅标本和文献资料,对高粱属植物的地理分布进行了整理和研究。高粱属植物约有29种,分布于全世界热带到温带地区,其中澳大利亚22种,亚洲15种,非洲9种,欧洲3种,地中海2种,美洲6种。中国有5种,分布在东北、西南到华南各省(区)。高粱属有5亚属,仅高粱亚属(subgen. Sorghum)延伸至新世界,其他亚属均分布在旧世界,高粱亚属覆盖非洲并扩散到全世界热带到温带地区;拟高粱亚属(subgen. Parasorghum)分布在非洲、亚洲、澳大利亚;有柄高粱亚属(subgen. Stiposorghum)主要分布在澳大利亚,个别种分布到亚洲;多毛高粱亚属(subgen. Chaetosorghum)分布在澳大利亚;异高粱亚属(subgen. Heterosorghum)分布在澳大利亚和亚洲。这表明澳大利亚东北部是高粱属的现代分布中心和多样化中心,非洲东北部和热带亚洲是否是高粱属的起源地尚需确证。%In order to accumulate data for the phylogenetic reconstruction of Sorghum, the geographical distribution of Sorghum Moench (Andropogoneae, Panicoideae, Poaceae) was studied by field investigation and reviewing specimen and literature. Sorghum, including about 29 species, is a representative group in the tribe Andropogoneae due to the paired heterogamous spikelets (one sessile, fertile; the other one pedicelled, staminate or sterile) made up racemes along each node of inlforescences. Sorghum species distribute in the tropical and subtropical to temperate regions, with the species number being 22, 15, 9, 3, 2 in Australia, Asia, Africa, Europe, and Mediterranean, respectively. In addition, six species have extended to the Americas. In China, five species distribute in northeastern, southwestern, and southern provinces. Among five subgenera of Sorghum, only subgen. Sorghum has representatives in the New World, other subgenera are

  15. Atividade de glutationa S-transferase na metabolização de acetochlor, atrazine e oxyfluorfen em milho (Zea mays L., sorgo (Sorghum bicolor L. e trigo (Triticum aestivum L. (Poaceae Glutathione S-transferase activity in acetochlor, atrazine and oxyfluorfen metabolization in maize (Zea mays L., sorghum (Sorghum bicolor L. and wheat (Triticum aestivumL. (Poaceae

    Directory of Open Access Journals (Sweden)

    Ethel Lourenzi Barbosa Novelli

    2002-05-01

    Full Text Available Este experimento foi conduzido para avaliar a seletividade em plantas dos herbicidas acetochlor, atrazine e oxyfluorfen em relação à atividade da glutationa S-transferase (GST em plantas de milho (Zea mays L., sorgo (Sorghum bicolor L. e trigo (Triticum aestivum L. (Poaceae. A atividade da GST foi detectada às 24, 48 e 72 horas após as aplicaç��es dos tratamentos. Os tratamentos do experimento consistiram de aplicação com água (controle, acetochlor (3 L.ha-1, atrazine (4 L.ha-1 e oxyfluorfen (1 L.ha-1. As maiores atividades de GST foram observadas na presença de acetochlor, principalmente às 48 horas após o tratamento. Esses aumentos foram 105, 148 e 118% em relação ao controle para milho, sorgo e trigo, respectivamente. É sugerido que a GST pode ter papel na degradação de acetochlor e pode ser uma das razões para a seletividade desse herbicida para essas culturas.This experiment was conducted to evaluate the acetochlor, atrazine and oxyfluorfen herbicides plant selectivity, in relation to glutathione S-transferase activity (GST in maize (Zea mays L., sorghum (Sorghum bicolor L. and wheat (Triticum aestivum L (Poaceae plants. GST activity was detected 24, 48 and 72 hours after treatment applications. The experiment's treatments consisted of spraying plants with water (control, acetochlor (3 L.ha-1`, atrazine (4 L.ha-1 and oxyfluorfen (1 L.ha-1. The highest GST activities were observed in presence of acetochlor, mainly at 48 hours after treatment. These increments were 105, 148 and 118% when compared to maize, sorghum and wheat control groups, respectively. It is suggested that the GST may have a role in acetochlor degradation and it may be a reason for this herbicide's selectivity in these crops.

  16. Whole genome surveys of rice, maize and sorghum reveal multiple horizontal transfers of the LTR-retrotransposon Route66 in Poaceae

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    Manicacci Domenica

    2009-03-01

    Full Text Available Abstract Background Horizontal transfers (HTs refer to the transmission of genetic material between phylogenetically distant species. Although most of the cases of HTs described so far concern genes, there is increasing evidence that some involve transposable elements (TEs in Eukaryotes. The availability of the full genome sequence of two cereal species, (i.e. rice and Sorghum, as well as the partial genome sequence of maize, provides the opportunity to carry out genome-wide searches for TE-HTs in Poaceae. Results We have identified an LTR-retrotransposon, that we named Route66, with more than 95% sequence identity between rice and Sorghum. Using a combination of in silico and molecular approaches, we are able to present a substantial phylogenetic evidence that Route66 has been transferred horizontally between Panicoideae and several species of the genus Oryza. In addition, we show that it has remained active after these transfers. Conclusion This study constitutes a new case of HTs for an LTR-retrotransposon and we strongly believe that this mechanism could play a major role in the life cycle of transposable elements. We therefore propose to integrate classe I elements into the previous model of transposable element evolution through horizontal transfers.

  17. A molecular phylogeny of Raddia and its allies within the tribe Olyreae (Poaceae, Bambusoideae) based on noncoding plastid and nuclear spacers.

    Science.gov (United States)

    Oliveira, Reyjane P; Clark, Lynn G; Schnadelbach, Alessandra S; Monteiro, Silvana H N; Borba, Eduardo L; Longhi-Wagner, Hilda M; van den Berg, Cassio

    2014-09-01

    The plastid spacer trnD-trnT and the nuclear ribosomal internal transcribed spacer (ITS) were sequenced for 37 samples of herbaceous bamboos (Poaceae: Olyreae), including all Raddia species and allied genera, as well as two members of the woody bamboos (tribes Bambuseae and Arundinarieae), in order to examine their relationships. The sequences were analyzed using maximum parsimony and Bayesian inference. Both the individual and combined analyses of ITS and trnD-trnT supported Olyreae as a monophyletic group. All species of Raddia also formed a well-supported monophyletic group, and combined datasets allowed us to outline some relationships within this group. Individual analyses indicated incongruence regarding the sister group of Raddia, with ITS data weakly indicating Raddiella malmeana whereas trnD-trnT data supported Sucrea maculata in this position. However, the combined analysis supported Sucrea as sister to Raddia, although the monophyly of Sucrea is not well supported. Parodiolyra is paraphyletic to Raddiella in all analyses; Olyra is also paraphyletic, with species of Lithachne, Arberella and Cryptochloa nested within it. Eremitis and Pariana appeared as an isolated clade within Olyreae, and the position of the New Guinean Buergersiochloa remains uncertain within this tribe. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Diversity in leaf anatomy, and stomatal distribution and conductance, between salt marsh and freshwater species in the C(4) genus Spartina (Poaceae).

    Science.gov (United States)

    Maricle, Brian R; Koteyeva, Nuria K; Voznesenskaya, Elena V; Thomasson, Joseph R; Edwards, Gerald E

    2009-01-01

    Leaf anatomy, stomatal density, and leaf conductance were studied in 10 species of Spartina (Poaceae) from low versus high salt marsh, and freshwater habitats. Internal structure, external morphology, cuticle structure, and stomatal densities were studied with light and electron microscopy. Functional significance of leaf structure was examined by measures of CO(2) uptake and stomatal distributions. All species have Kranz anatomy and C(4)delta(13)C values. Freshwater species have thin leaves with small ridges on adaxial sides and stomata on both adaxial and abaxial sides. By contrast, salt marsh species have thick leaves with very pronounced ridges on the adaxial side and stomata located almost exclusively on adaxial leaf surfaces. Salt marsh species also have a thicker cuticle on the abaxial than on the adaxial side of leaves, and CO(2) uptake during photosynthesis is restricted to the adaxial leaf surface. Salt marsh species are adapted to controlling water loss by having stomata in leaf furrows on the adaxial side, which increases the boundary layer, and by having large leaf ridges that fit together as the leaf rolls during water stress. Differences in structural-functional features of photosynthesis in Spartina species are suggested to be related to adaptations to saline environments.

  19. Physical mapping of 5S and 18S-5.8S-26S RNA gene families in polyploid series of Cenchrus ciliaris Linnaeus, 1771 (Poaceae

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    Amina Kharrat-Souissi

    2012-08-01

    Full Text Available The Buffelgrass (Cenchrus ciliaris L., Poaceae is one of the most important pasturage grasses due to its high productivity and good forage qualities. This species possess a high adaptability to bioclimatic constraints of arid zones and may be used for the restoration of degraded arid ecosystems. Tunisian populations present three ploidy levels (4x, 5x and 6x with a basic chromosome number x=9. This study reported for the first time the distribution of the ribosomal genes (rRNA for pentaploid and hexaploid cytotypes of C. ciliaris. Molecular cytogenetic study using double fluorescence in situ hybridization has shown that the two rDNA families, 5S and 18S-5.8S-26S (18S, displayed intraspecific variation in number of loci among different ploidy levels. Each ploidy level was characterized by specific number of both 5S and 18S rDNA loci (two loci in tetraploid, five in pentaploid and six in hexaploid level. For three studied cytotypes (4x, 5x and 6x all 5S rDNA loci were localized on the subcentromeric region of chromosomes, while 18S loci were situated on the telomeric region of short chromosome arms. Data of the FISH experiments show proportional increase of ribosomal loci number during polyploidization processes.

  20. Estudios sobre la variación estructural de la sinflorescencia en el género Axonopus (Poaceae, Panicoideae, Paniceae: tipología y tendencias evolutivas

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    Diego Giraldo Cañas

    2000-01-01

    Full Text Available Giraldo-Cañas, D. 2000. Estudios sobre la variación estructural de la sinflorescencia en elgénero Axonopus (Poaceae, Panicoideae, Paniceae: tipología y tendencias evolutivas. Darwiniana 38(3-4: 209-218.Se estudió la tipología de la sinflorescencia del género neotropical Axonopus P. Beauv. utilizando lametodología y terminología de la escuela de Troll. Se analizaron representantes de 52 de las ca. 75 especiesdel género. En todas las especies la sinflorescencia es politélica y truncada. De acuerdo con este estudio,la unidad de floración plesiomórfica se encuentra en la serie Barbigeri G. A. Black. La sinflorescencia deAxonopus pudo derivarse de una forma ancestral a través de los siguientes pasos: 1.- truncamiento del ejeprincipal; 2.- homogeneización completa; 3.- reducción de los paracladios cortos; 4.- disminución delnúmero de paracladios largos y 5.- truncamiento de los paracladios largos. Se discuten las relacionesmorfológicas y se comentan algunas posibles tendencias evolutivas.

  1. Physical mapping of 5S and 18S-5.8S-26S RNA gene families in polyploid series of Cenchrus ciliaris Linnaeus, 1771 (Poaceae)

    Science.gov (United States)

    Kharrat-Souissi, Amina; Siljak-Yakovlev, Sonja; Pustahija, Fatima; Chaieb, Mohamed

    2012-01-01

    Abstract The Buffelgrass (Cenchrus ciliaris L., Poaceae) is one of the most important pasturage grasses due to its high productivity and good forage qualities. This species possess a high adaptability to bioclimatic constraints of arid zones and may be used for the restoration of degraded arid ecosystems. Tunisian populations present three ploidy levels (4x, 5x and 6x) with a basic chromosome number x=9. This study reported for the first time the distribution of the ribosomal genes (rRNA) for pentaploid and hexaploid cytotypes of Cenchrus ciliaris. Molecular cytogenetic study using double fluorescence in situ hybridization has shown that the two rDNA families, 5S and 18S-5.8S-26S (18S), displayed intraspecific variation in number of loci among different ploidy levels. Each ploidy level was characterized by specific number of both 5S and 18S rDNA loci (two loci in tetraploid, five in pentaploid and six in hexaploid level). For three studied cytotypes (4x, 5x and 6x) all 5S rDNA loci were localized on the subcentromeric region of chromosomes, while 18S loci were situated on the telomeric region of short chromosome arms. Data of the FISH experiments show proportional increase of ribosomal loci number during polyploidization processes. PMID:24260668

  2. The validity of the Asteraceae: Poaceae fossil pollen ratio in discrimination of the southern African summer- and winter-rainfall zones

    Science.gov (United States)

    Fitchett, Jennifer M.; Bamford, Marion K.

    2017-03-01

    Situated at the transition between the mid-latitudes and the sub-tropics, southern Africa has a climatic dichotomy between winter- and summer-rainfall zones (WRZ and SRZ). The latitudinal extent of the winter-rainfall zone during the late Pleistocene remains contentiously debated within the regional palaeoscience literature. One method posited to reflect the seasonality of rainfall at a given location throughout late Pleistocene records for South Africa is the ratio of fossil pollen Asteraceae to Poaceae. Although adopted for a range of southern African locations, the veracity of this method has not been tested. This study explores the extent to which this ratio can discriminate between the SRZ and WRZ, and the extent of the region subject to fluctuation during the late Quaternary. The ratio is found to successfully discriminate regions which are, and would have remained during the past 20,000 cal yr BP, in the SRZ and WRZ exclusively. On the basis of these statistics, it appears that WRZ conditions can be inferred from ratio scores >0.6 and SRZ conditions from scores <0.2. For locations situated between 28 and 32°S, no clear discrimination can be made. It is argued that this region has been subjected to fluctuations in the latitudinal extent of the Westerlies and consequently in the influence of mid-latitude cyclones over the past 20,000 cal yr BP, with the rugged topography of the Drakensberg Mountains resulting in a complex precipitation climatology controlled by both frontal and orographic uplift.

  3. Transcriptome de novo assembly from next-generation sequencing and comparative analyses in the hexaploid salt marsh species Spartina maritima and Spartina alterniflora (Poaceae).

    Science.gov (United States)

    Ferreira de Carvalho, J; Poulain, J; Da Silva, C; Wincker, P; Michon-Coudouel, S; Dheilly, A; Naquin, D; Boutte, J; Salmon, A; Ainouche, M

    2013-02-01

    Spartina species have a critical ecological role in salt marshes and represent an excellent system to investigate recurrent polyploid speciation. Using the 454 GS-FLX pyrosequencer, we assembled and annotated the first reference transcriptome (from roots and leaves) for two related hexaploid Spartina species that hybridize in Western Europe, the East American invasive Spartina alterniflora and the Euro-African S. maritima. The de novo read assembly generated 38 478 consensus sequences and 99% found an annotation using Poaceae databases, representing a total of 16 753 non-redundant genes. Spartina expressed sequence tags were mapped onto the Sorghum bicolor genome, where they were distributed among the subtelomeric arms of the 10 S. bicolor chromosomes, with high gene density correlation. Normalization of the complementary DNA library improved the number of annotated genes. Ecologically relevant genes were identified among GO biological function categories in salt and heavy metal stress response, C4 photosynthesis and in lignin and cellulose metabolism. Expression of some of these genes had been found to be altered by hybridization and genome duplication in a previous microarray-based study in Spartina. As these species are hexaploid, up to three duplicated homoeologs may be expected per locus. When analyzing sequence polymorphism at four different loci in S. maritima and S. alterniflora, we found up to four haplotypes per locus, suggesting the presence of two expressed homoeologous sequences with one or two allelic variants each. This reference transcriptome will allow analysis of specific Spartina genes of ecological or evolutionary interest, estimation of homoeologous gene expression variation using RNA-seq and further gene expression evolution analyses in natural populations.

  4. Padrão de resposta de Mimosa pudica e Senna obtusifolia à atividade potencialmente alelopática de espécies de Poaceae Response pattern of Mimosa pudica e Senna obtusifolia to potentially allelopathic activity of Poaceae species

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    A.P.S. Souza Filho

    2010-01-01

    Full Text Available A alelopatia é um importante mediador de interferências que alteram a dinâmica de espécies de plantas em sistemas agrícolas. Neste trabalho, procurou-se determinar a existência de padrão de respostas das plantas daninhas Mimosa pudica e Senna obtusifolia a espécies da família Poaceae, via interação entre espécies e frações e ordenamento dos efeitos. Bioensaios de germinação de sementes e alongamento da radícula e do hipocótilo foram desenvolvidos, em condições controladas. Os testes foram realizados utilizando-se extratos hidroalcoólicos na concentração de 1,0% das frações folha, raiz e sementes de quatro espécies de Poaceae. Diferenças na intensidade dos efeitos para os fatores espécie e fração foram verificadas. O padrão de atividade observado foi de Paspalum maritimum apresentar as inibições mais intensas. Entre as espécies de Brachiaria, as inibições mais intensas foram produzidas por B. brizantha. Houve resposta efetiva para a especificidade entre espécies e fração para a germinação e alongamento da radícula, especialmente na espécie Mimosa pudica. Apenas para os extratos de P. maritimum foram observadas especificidade e efetividade em relação à germinação de sementes e alongamento da radícula da espécie Senna obtusifolia. A fração folha foi mais efetiva nas inibições, sobretudo na espécie P. maritimum. Comparativamente, a espécie Mimosa pudica foi mais sensível aos efeitos dos extratos, especialmente em relação ao desenvolvimento da radícula e do hipocótilo. A intensidade dos efeitos alelopáticos variou na seguinte ordem: alongamento da radícula > germinação de sementes > alongamento do hipocótilo. A ordenação dos resultados, para os indicadores de inibição, indicou discriminação no padrão para as espécies receptoras, o que sugere especificidade dos extratos.Allelopathy is an important device to measure interferences affecting the dynamics of plant species in

  5. Protozoa, Nematoda and Lumbricidae in the rhizosphere of Hordelymus europeaus (Poaceae): faunal interactions, response of microorganisms and effects on plant growth.

    Science.gov (United States)

    Alphei, Jörn; Bonkowski, Michael; Scheu, Stefan

    1996-04-01

    Interactions among protozoa (mixed cultures of ciliates, flagellates and naked amoebae), bacteria-feeding nematodes (Pellioditis pellio Schneider) and the endogeic earthworm species Aporrectodea caliginosa (Savigny) were investigated in experimental chambers with soil from a beechwood (Fagus sylvatica L.) on limestone. Experimental chambers were planted with the grass Hordelymus europeaus L. (Poaceae) and three compartments separated by 45-μm mesh were established: rhizosphere, intermediate and non-rhizosphere. The experiment lasted for 16 weeks and the following parameters were measured at the end of the experiment: shoot and root mass of H. europaeus, carbon and nitrogen content in shoots and roots, density of ciliates, amoebae, flagellates and nematodes, microbial biomass (SIR), basal respiration, streptomycin sensitive respiration, ammonium and nitrate contents, phosphate content of soil compartments. In addition, leaching of nutrients (nitrogen and phosphorus) and leachate pH were measured at regular intervals in leachate obtained from suction cups in the experimental chambers. Protozoa stimulated the recovery of nitrifying bacteria following defaunation (by chloroform fumigation) and increased nitrogen losses as nitrate in leachate. In contrast, protozoa and nematodes reduced leaching of phosphate, an effect ascribed to stimulation of microbial growth early in the experiment. Earthworms strongly increased the amount of extractable mineral nitrogen whereas it was strongly reduced by protozoa and nematodes. Both protozoa and nematodes reduced the stimulatory effect of earthworms on nitrogen mineralization. Microbial biomass, basal respiration, and numbers of protozoa and nematodes increased in the vicinity of the root. Protozoa generally caused a decrease in microbial biomass whereas nematodes and earthworms reduced microbial biomass only in the absence of protozoa. None of the animals studied significantly affected basal respiration, but specific respiration

  6. On the origins of the tetraploid Bromus species (section Bromus, Poaceae): insights from internal transcribed spacer sequences of nuclear ribosomal DNA.

    Science.gov (United States)

    Ainouche, M L; Bayer, R J

    1997-10-01

    The internal transcribed spacer (ITS) region of nuclear ribosomal DNA from 22 diploid and tetraploid annual Bromus species of section Bromus (Poaceae) and three species belonging to other Bromus sections, Bromus catharticus (section Ceratochloa), Bromus anomalus (section Pnigma), and Bromus sterilis (section Genea), were investigated by PCR amplification and direct sequencing. The length of the ITS-1 region varied from 215 to 218 bp, and that of the ITS-2 region from 215 to 216 bp, in the species analyzed. ITS-1 was more variable and provided more informative sites (49) than ITS-2 (32). No variation was encountered within species. In pairwise comparison among species of section Bromus, sequence divergence ranged from 0.0 to 8.0% for the combined ITS-1 and ITS-2 regions. Parsimony analysis using Avena longiglumis and Hordeum vulgare as outgroups resulted in well-resolved phylogenetic trees and showed that section Bromus is monophyletic according to the species analyzed outside of the section. The analysis clarified the phylogenetic relationships among monogenomic (diploid) species. Introduction of the allotetraploid species did not change the general topology of the trees obtained using only the diploid species. Although some tetraploid-diploid species relationships will have to be clarified with faster evolving markers, the ITS sequences are shown to be useful for assessing evolutionary relationships among closely related Bromus species, as well as for clarifying taxonomic problems in previously controversial cases (e.g., Bromus alopecuros and Bromus caroli-henrici). New hypotheses are proposed concerning the origin of several allotetraploid species. For example, it is shown that the tetraploid Bromus hordeaceus diverged earlier than all other species of section Bromus, excluding the diploid B. caroli-henrici, which is found to be basal in this group. The tetraploid Bromus arenarius, which was considered a hybrid between sections Bromus and Genea, and the

  7. ¿Al afinal, qué es aprendizaje siginificativo?

    OpenAIRE

    Moreira, Marco Antonio

    2012-01-01

    Se hace una descripción detallada de la teoría del aprendizaje significativo en la visión clásica de David Ausubel, según la lectura, o relectura, del autor. La teoría no se presenta como nueva, sino como actual. Se argumenta que ha habido una apropiación superficial, polisémica, del concepto de aprendizaje significativo, de modo que cualquier estrategia de enseñanza ha pasado a tener el aprendizaje significativo como objetivo. Sin embargo, en la práctica la mayoría de esas estrategias, o la ...

  8. CROMOSOMAS EN VERNONIA PLATENSIS Y ESPECIES AFINES (ASTERACEAE

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    Massimiliano Dematteis

    2010-11-01

    Full Text Available Fueron analizados los cromosomas somáticos de Vernonia platensis y otras tres especies estrechamente relacionadas. Todas éstas especies pertenecen a la subsección o serie Flexuosae, que es el único grupo americano con el número básico de cromosomas x = 10. En el presente trabajo se analizan los cromosomas somáticos de cuatro especies del grupo Flexuosae; se dan a conocer dos nuevos citotipos para V. platensis y se presentan por primera vez los cariotipos de V. verbascifolia y V. platensis. Los resultados del análisis de los cromosomas son los siguientes: V.flexuosa, 2n = 40 (28m + 12sm; V.lepidifera, 2n = 20 (8m + 2m-sm + 10sm, V. platensis, 2n = 20 (10m + 2m-sm + 8sm, 2n=40, 2n=60, 2n=80 y V.verbascifolia, 2n=20 (8m + 4m-sm + 8sm. El citotipo 4x, 6x y 8x de V.platensis presenta el mismo cariotipo diploide lo que sugiere un origen autopoliploide.  Los cariotipos de las especies aquí reportadas difieren principalmente en longitud total, asimetría y número de metacéntricos y submetacéntricos. Muestran también variación en el número, forma y ubicación de los satélites. Los resultados se discuten en relación a la posición taxonómica de las especies y los estudios cromosómicos previos en el grupo.

  9. DESENVOLVIMENTO RURAL: AFINAL, SOBRE O QUE ESTAMOS FALANDO?

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    Daniela Dias Kühn

    2015-07-01

    Full Text Available A expressão desenvolvimento vem sendo cada vez mais utilizada e está consolidada no estudo das realidades socioeconômicas. Entretanto, há, ainda, de se limitar o alcance da expressão, bem como a qualificação. O presente artigo discute o significado da expressão desenvolvimento rural, reunindo autores e buscando tematizar sobre os conceitos envolvidos na expressão. O objetivo principal deste trabalho é, a partir de uma revisão bibliográfica do conceito de desenvolvimento rural e de uma contextualização da Abordagem das Capacitações, indicar como a referida abordagem pode contribuir para a construção de um conceito de desenvolvimento rural mais adequado à diversidade inerente ao ambiente em análise. Para isso, foi realizada uma breve revisão daquilo que vem sendo discutido sobre processos de desenvolvimento e como esse processo se associa à expressão rural. O termo desenvolvimento é analisado a partir da construção de suas interpretações no processo de conceituação e desenvolvimento teórico. Foi possível reconhecer os principais adjetivos, bem como a evolução dessas discussões nos últimos 30 anos. Por fim, é identificado um conceito associado à Abordagem das Capacitações, apresentado pelo economista indiano Amartya Sen. A ideia de desenvolvimento rural, associada à Abordagem das Capacitações, leva a uma concepção que identifica o desenvolvimento rural como um aumento da possibilidade de escolha dos indivíduos que residem em ambientes constituídos por relações socioeconômicas, geográficas e culturais que evidenciam, por meio da paisagem, a utilização e (ou preservação de aspectos relacionados à Natureza cuja reprodução não é inteiramente dependente e (ou condicionada pela ação humana.

  10. La apicultura sevillana afines de la Edad Media

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    Carmona Ruiz, María Antonia

    2000-06-01

    Full Text Available The purpose of this article is to present the apiculture industry in Seville in the Late Middle Ages. Due to the importance of this economic activity, "ordenanzas" (bylaws, which regulated the exploitation of the apiaries, were passed shortly after the conquest of Seville. By means of these "ordenanzas" and other documents which made reference to beekeeping, I have tried to reconstruct the map of the areas dedicated to apiculture in Seville, by indicating where the beehives were located and how they were exploited. I will deal especially with the existence of institutions relating to beekeeping, for example the "alcaldes de los colmeneros" (municipal officials who supervised and controlled the activities of the beekeepers. I will also deal with the owners of the beehives and the conflicts they had with other economic activities carried out in the same place. I will pay special attention to the problems the beekeepers had with the farmers and stockbreeders, and to the problems existing among the beekeepers themselves. These problems forced the creation of boundaries and regulated distances between the different exploitations.[fr] Cet article traite sur l'activité apicole à Seville pendant le Bas Moyen Âge. L'importance de cette activité économique entraîne la promulgation -peu de temps après la conquête de la ville- d'ordonnances sur l'exploitation des ruches. En partant de ces ordonnances et d'autres documents relatifs à la même activité, nous tentons de déterminer les espaces apicoles du territoire communal de Seville et de préciser l'emplacement et le mode d'exploitation des ruches. Nous soulignons l'existence d'institutions propres à cette activité—celle des alcaldes de los colmeneros (juges des apiculteurs, par exemple— et consacrons une partie de notre travail aux propriétaires de ruches et aux conflits surgis, soit entre eux, soit entre l'apiculture et d'autres activités économiques profitant des mêmes espaces, tout spécialement l'agriculture et l'élevage; ces conflits ont obligé à bien établir les limites et les distances entre les différentes exploitations.

  11. Restaurando a Governabilidade: O Brasil (afinal se Acertou?

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    Faucher Philippe

    1998-01-01

    Full Text Available The article aims to link recent changes in Brazil's political and economic situation with the question of governance in a democratic setting. It shows that a set of policies are only as good as the political support which enables their implementation. As memories of the economic nightmare of the past decade fade and the costs of sustaining price stability through needed budget cuts continue to be felt, popular dissatisfaction with reform is bound to increase. The Cardoso Administration's incremental strategy of state reform and its step-by-step approach to crucial human rights issues reflect the conflicting pressures the government must balance in order to make policy advances. As democratization increases the autonomous representation of societal interests and the structure of Brazilian politics continues to erect legislative obstacles, incrementalism seems the most appropriate pace for producing real, long-lasting reform.

  12. Gramíneas (Poaceae da Área de Relevante Interesse Ecológico (ARIE "Santuário de Vida Silvestre do Riacho Fundo", Distrito Federal, Brasil

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    Rodrigues-da-Silva Robson

    2003-01-01

    Full Text Available Neste trabalho relata-se o levantamento florístico das espécies de Poaceae da Área de Relevante Interesse Ecológico (ARIE "Santuário de Vida Silvestre do Riacho Fundo", Distrito Federal, Brasil. Foram encontradas 107 espécies, distribuídas em 41 gêneros, sendo 82 nativas e 25 exóticas. São apresentadas chaves analíticas para gêneros e espécies, além de ilustrações para os táxons identificados. Coelorachis aurita (Steud. A. Camus é citada pela primeira vez para a flora do Distrito Federal.

  13. Como se posicionam os professores perante a existência e utilização de jardins zoológicos e parques afins? Resultados de uma investigação How do teachers stand with respect to the existence and use of zoological gardens and similar parks? Results of an investigation

    Directory of Open Access Journals (Sweden)

    António Almeida

    2008-08-01

    Full Text Available O presente estudo insere-se numa investigação mais ampla que pretendeu verificar a incidência de concepções ambientalistas de teor antropocêntrico, biocêntrico e ecocêntrico em docentes dos diferentes ciclos de escolaridade não superior e que se envolvem em projectos de Educação Ambiental (EA. Para tal, foram entrevistados 60 docentes sobre vários assuntos relacionados com a temática ambiental, entre os quais o dos jardins zoológicos e parques afins. No tratamento dos dados, os docentes entrevistados foram divididos em dois grupos em função da proveniência de ciclos com e sem monodocência (o 1º grupo foi constituído por 15 educadores de infância e 15 professores do 1º Ciclo; o 2º grupo, por 15 professores do 2º Ciclo e 15 do 3º Ciclo e Secundário. Essa divisão foi considerada especialmente pertinente para o tema em análise uma vez que os jardins zoológicos e parques afins tradicionalmente pretendem captar um público mais jovem. Assim, nos professores do 1º grupo, poderia eventualmente acentuar-se mais uma conflitualidade entre o seu interesse didáctico e eventuais valores trabalhados em EA. No entanto, não se verificaram diferenças estatisticamente significativas entre os grupos em termos da incidência das diferentes perspectivas ambientalistas, tendo-se a maioria dos docentes posicionado de um ponto de vista biocêntrico, embora com uma maior frequência para o 1º grupo. Perante a surpresa manifestada pelo teor da entrevista, tivemos a percepção de que os professores raramente abordam temas polémicos com os seus alunos no âmbito dos projectos de EA.This study is part of a wider investigation that seeks to observe the presence of environmentalist conceptions of anthropocentric, bio-centric and eco-centric characters among teachers from the various levels of schooling below higher education involved in projects of Environmental Education (EE. Sixty teachers were interviewed on various subjects associated to

  14. Chemical composition and cardiovascular effects induced by the essential oil of Cymbopogon citratus DC. Stapf, Poaceae, in rats Composição química e efeitos cardiovasculares do óleo essencial de Cymbopogon citratus DC. Stapf, Poaceae, em ratos

    Directory of Open Access Journals (Sweden)

    Flávia V. Moreira

    2010-12-01

    Full Text Available Cymbopogon citratus DC. Stapf, Poaceae, is used in the folk medicine for hypertension treatment. This work investigated the chemical composition and cardiovascular effects in rats of C. citratus essential oil (EOCC. A phytochemical screening demonstrated the presence of eight constituents, being geranial the major compound (43.08%. In rats, EOCC (1, 5, 10, and 20 mg/kg, i.v. induced transient hypotension and bradycardia that were attenuated by atropine and sodium thiopental, but not by L-NAME or indomethacin. In rings of rat superior mesenteric artery pre-contracted with phenylephrine, EOCC (1 to 3000 µg/mL induced relaxation that was not affected after removal of the endothelium, after TEA or in rings pre-contracted with KCl (80 mM. Furthermore, EOCC (1000 µg/mL was not able to induce additional effect on maximal relaxation of nifedipine (10 µM. In conclusions, EOCC induces hypotension, possibly by reduction in vascular resistance caused by inhibition of the Ca2+ influx, and bradycardia probably due to an activation of cardiac muscarinic receptors.C. citratus é utilizada na medicina popular para tratar hipertensão. Este trabalho investigou a composição química e os efeitos cardiovasculares do óleo essencial do C. citratus (OECC. Foram identificados oito constituintes no OECC, sendo geranial o majoritário (43,08%. Em ratos, o OECC (1, 5, 10 e 20 mg/kg, i.v. induziu hipotensão e bradicardia que foram atenuadas pela atropina e tiopental sódico, mas não por L-NAME ou indometacina. Em anéis de artéria mesentérica de ratos pré-contraídos com fenilefrina, o OECC (1 a 3000 µg/mL induziu relaxamento que não foi afetado após remoção do endotélio, após TEA ou em anéis pré-contraídos com KCl (80 mM. Além disso, o OECC (1000 µg/mL não induziu efeito adicional sobre o relaxamento máximo da nifedipina (10 µM. Em conclusão, o OECC induz hipotensão possivelmente devido à redução da resistência vascular que pode ser causada

  15. Avaliação da produção polínica de Bromus catharticus Vahl e Guadua trinii (Nees Nees ex Rupr. (Poaceae para a interpretação de dados fósseis

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    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2016v29n4p9 Neste trabalho é apresentada a produção polínica por antera, por flor e por espigueta das espécies Bromus catharicus (campestre e Guadua trinii (florestal, ambas da família Poaceae, que apresentam a síndrome da polinização divergente. Com o objetivo de averiguar diferenças de produção polínica dependente do sistema de polinização, foram coletadas dez anteras de cada táxon que após maceradas foram contabilizados os grãos de pólen em câmara de Neubauer. As morfologias polínicas também foram observadas sob microscopia óptica para estabelecer relação entre produção-morfologia dos grãos de pólen. A espécie anemófila Bromus catharticus (2.556.000 grãos de pólen por espigueta apresenta o dobro de produção polínica por antera e por espigueta em relação à espécie com assistência biótica para polinização Guadua trinii (1.716.000 grãos de pólen por espigueta. O tamanho do grão de pólen é inversamente proporcional à produção polínica. A ornamentação microequinada não esperada para espécies anemófilas foi observada nos dois táxons. Os resultados indicam que a frequência de espécies florestais de Poaceae em registros quaternários pode ser subestimada, enquanto táxons campestres de gramíneas são superestimados, interferindo na representação de suas respectivas floras no passado.

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

    Directory of Open Access Journals (Sweden)

    LEANDRO V. FERREIRA

    2016-01-01

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

  17. Use of Ethanol/Diesel Blend and Advanced Calibration Methods to Satisfy Euro 5 Emission Standards without DPF Utilisation d’un carburant Diesel éthanolé à l’aide de méthodes de calibration avancées afin de satisfaire les normes Euro 5 sans filtre à particules

    Directory of Open Access Journals (Sweden)

    Magand S.

    2011-11-01

    innovative calibration methods, based on the simultaneous optimisation of engine basic settings and cold correction maps, are introduced in order to better suit to the new formulation impact on combustion and catalyst light-off and to drop off engine-out unburned hydrocarbons and carbon monoxide emissions. This stage allows pushing forward the work on test bed facilities in order to reduce the amount of vehicle tests. Tests on a chassis dynamometer are only used to validate the engine test bed results and to perform final tuning of cold correction maps. This alternative blend shows potential to achieve Euro 5 standard with Euro 4 Diesel vehicle configuration, without any hardware modification and without a Diesel particulate filter in the exhaust line. Such an innovative fuel formulation seems to be an interesting answer to the trade-off in the forthcoming years between cost and emissions reduction to achieve sustainable mobility. The presented calibration methods and tools allow to fully take advantage of this alternative fuel in a reduced time scale. L’utilisation des biocarburants s’est développée durant ces dernières années de façon importante afin de diversifier les sources d’énergies et de limiter la hausse des émissions de gaz à effet de serre du secteur des transports. L’un des carburants renouvelables les plus adaptés à une production de masse est l’éthanol. Celui-ci est aujourd’hui principalement utilisé dans les moteurs à allumage commandé, alors que la part des véhicules Diesel sur le marché européen est de l’ordre de 60 %. Ce constat nous a incité à proposer une formulation innovante utilisant de l’éthanol pour les applications Diesel. Les principaux verrous technologiques pour cette utilisation sont la miscibilité, la température d’éclair, la lubrification ou encore l’indice de cétane. Des travaux ont été réalisés pour optimiser la formulation contenant de l’éthanol, des biodiesels de première et seconde g

  18. Systematic Investigation of FLOWERING LOCUS T-Like Poaceae Gene Families Identifies the Short-Day Expressed Flowering Pathway Gene, TaFT3 in Wheat (Triticum aestivum L.)

    Science.gov (United States)

    Halliwell, Joanna; Borrill, Philippa; Gordon, Anna; Kowalczyk, Radoslaw; Pagano, Marina L.; Saccomanno, Benedetta; Bentley, Alison R.; Uauy, Cristobal; Cockram, James

    2016-01-01

    To date, a small number of major flowering time loci have been identified in the related Triticeae crops, bread wheat (Triticum aestivum), durum wheat (T. durum), and barley (Hordeum vulgare). Natural genetic variants at these loci result in major phenotypic changes which have adapted crops to the novel environments encountered during the spread of agriculture. The polyploid nature of bread and durum wheat means that major flowering time loci in which recessive alleles confer adaptive advantage in related diploid species have not been readily identified. One such example is the PPD-H2 flowering time locus encoded by FLOWERING LOCUS T 3 (HvFT3) in the diploid crop barley, for which recessive mutant alleles confer delayed flowering under short day (SD) photoperiods. In autumn-sown barley, such alleles aid the repression of flowering over the winter, which help prevent the development of cold-sensitive floral organs until the onset of inductive long day (LD) photoperiods the following spring. While the identification of orthologous loci in wheat could provide breeders with alternative mechanisms to fine tune flowering time, systematic identification of wheat orthologs of HvFT3 has not been reported. Here, we characterize the FT gene families in six Poaceae species, identifying novel members in all taxa investigated, as well as FT3 homoeologs from the A, B and D genomes of hexaploid (TaFT3) and tetraploid wheat. Sequence analysis shows TaFT3 homoeologs display high similarity to the HvFT3 coding region (95–96%) and predicted protein (96–97%), with conservation of intron/exon structure across the five cereal species investigated. Genetic mapping and comparative analyses in hexaploid and tetraploid wheat find TaFT3 homoeologs map to the long arms of the group 1 chromosomes, collinear to HvFT3 in barley and FT3 orthologs in rice, foxtail millet and brachypodium. Genome-specific expression analyses show FT3 homoeologs in tetraploid and hexaploid wheat are upregulated

  19. Morphological development of Paspalum paniculatum L. (Poaceae

    Directory of Open Access Journals (Sweden)

    Daniela Fávero

    2006-12-01

    Full Text Available This work aimed to describe the morphological development of Paspalum paniculatum. Individual plants were cultivated in pots and evaluated at seven ages: 31, 58, 93, 123, 134, 144 and 176 days of growth from the emergence. The species showed medium height (50cm, clonal growth, with aerial stems of culm-type, semi-erect, and underground stems of rhizome-type, with reproductive tillers over 100cm in length. The shoot dry matter (DM at flowering stage was composed by equivalent quantities of culms (C and leaves (L, in a L:C relationship of 1.5. After 176 days’ growth, the plants had accumulated 23.5g of DM, consisting of roots (29.06% and rhizomes (15.91%, totaling 44.97% of the DM in the underground part, leaves (21.89%, culms (26.32% and inflorescences (6.83%. The expressive formation of DM in the underground part suggests resistance to grazing and adverse climatic conditions, in addition to a possible aptitude for revegetation of areas subject to erosion.

  20. Spaceflight reduces somatic embryogenesis in orchardgrass (Poaceae)

    Science.gov (United States)

    Conger, B. V.; Tomaszewski, Z. Jr; McDaniel, J. K.; Vasilenko, A.

    1998-01-01

    Somatic embryos initiate and develop from single mesophyll cells in in vitro cultured leaf segments of orchard-grass (Dactylis glomerata L.). Segments were plated at time periods ranging from 21 to 0.9 d (21 h) prior to launch on an 11 d spaceflight (STS-64). Using a paired t-test, there was no significant difference in embryogenesis from preplating periods of 14 d and 21 d. However, embryogenesis was reduced by 70% in segments plated 21 h before launch and this treatment was significant at P=0.0001. The initial cell divisions leading to embryo formation would be taking place during flight in this treatment. A higher ratio of anticlinal:periclinal first cell divisions observed in the flight compared to the control tissue suggests that microgravity affects axis determination and embryo polarity at a very early stage. A similar reduction in zygotic embryogenesis would reduce seed formation and have important implications for long-term space flight or colonization where seeds would be needed either for direct consumption or to grow another generation of plants.

  1. NOVELTIES IN PANICUM (POACEAE FROM INDIA

    Directory of Open Access Journals (Sweden)

    V. N. NAIK

    1980-03-01

    Full Text Available Four novelties in the genus Panicum L. namely P. phoiniclados,P. deccanense and P. paianum together with its variety minor have beendescribed from materials collected from the Marathwada region of theDeecan plateau.

  2. Distribution of Vulpia species (Poaceae in Poland

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    Ludwik Frey

    2011-01-01

    Full Text Available The distribution of four species of the genus Vulpia [V. myuros (L. C.C. Gmel., V. bromoides (L. S.F. Gray, V. ciliata Dumort. and V. geniculata (L. Link] reported in Poland has been studied. Currently, V. myuros and especially V. bromoides are very rare species, and their greatest concentration can be found only in the Lower Silesia region. The number of their localities decreased after 1950 and it seems resonable to include both species in the "red list" of threatened plants in Poland: V. myuros in the EN category, V. bromoides in the CR category. V. ciliata and V. geniculata are very rare ephemerophytes and their localities not confirmed during ca 60 years are of historical interest only.

  3. A taxonomic revision of Secale (Triticeae, Poaceae)

    DEFF Research Database (Denmark)

    Frederiksen, Signe Elisabeth; Petersen, Gitte

    1998-01-01

    Several taxa have previously been recognized within Secale, but most of them are difficult or even impossible to distinguish morphologically. We recognize only three species: S. sylvestre, S. strictum, and S. cereale. Secale strictum has priority over S. montanum and has two subspecies, ssp. stri...

  4. [Leaf epidermis ultrastructure of Zeugites (Poaceae: Panicoideae)].

    Science.gov (United States)

    Soriano, Ana María; Terrazas, Teresa; Dávila, Patricia

    2011-06-01

    The genus Zeugites comprises eleven species of neotropical grasses and it is principally distributed in Mexico, with some species extending to the Caribbean region, Central and South America. In this work, leaf epidermis ultrastructure of 11 species is described by the use of scanning electron microscopy. At least three specimens per species, that included herbarium and collected specimens, were used. An identification key and specific descriptions are included, in which the distinctive epidermal features are highlighted. The taxonomic valuable characters found were the following: presence or absence of prickles and macrohairs, intercostals short cells form and silica body form. Based on leaf epidermis characteristics, Zeugites species can be arranged into three groups: (1) species that lack prickles (Z. americana, Z. mexicana, Z. pringlei, Z. munroana and Z. sagittata); and lack macro hairs, with the exception of Z. pringlei; (2) species that have prickles (Z. latifolia and Z. smilacifolia); (3) species that have both, prickles and macrohairs (Z. capillaris, Z. hackelii, Z. pittieri and Z. sylvatica). The morphological features of leaf epidermis, support the relationship between the tribes Centotheceae and Paniceae.

  5. Two New American Species of Hordeum (Poaceae)

    DEFF Research Database (Denmark)

    Bothmer, Roland Von; Jacobsen, Niels; Bagger Jørgensen, Rikke

    1985-01-01

    Two new species of Hordeum are described, viz. the diploid H. erectifolium, native to Argentina, and H. guatemalense, native to Guatemala.......Two new species of Hordeum are described, viz. the diploid H. erectifolium, native to Argentina, and H. guatemalense, native to Guatemala....

  6. Genome Evolution in the Genus Sorghum (Poaceae)

    OpenAIRE

    Price, H. James; Dillon, Sally L.; HODNETT, GEORGE; Rooney, William L.; Ross, Larry; Johnston, J Spencer

    2005-01-01

    • Background and Aims The roles of variation in DNA content in plant evolution and adaptation remain a major biological enigma. Chromosome number and 2C DNA content were determined for 21 of the 25 species of the genus Sorghum and analysed from a phylogenetic perspective.

  7. Diseño de una cocina solar para actividades de camping o afines

    OpenAIRE

    Monsalvo Londoño, Luis Carlos; Zamora Suárez, Óscar Hernando

    2009-01-01

    Por medio de este trabajo se pretende dar a conocer la ventaja funcional que tienen las cocinas solares durante el desarrollo de algunas actividades al aire libre como es el picnic o el camping -- Adicionalmente se busca concebir un producto diseñado, inicialmente en consideración a las demandas asociadas a los grupos de scouts, desde su estilo de vida, hábitos comunes de consumo y el contexto en el cual se desenvuelven -- Para lograr obtener un producto que pueda vincularse a este usuario en...

  8. CONJUNTOS DE CONTROL DE SISTEMAS LINEALES Y AFINES. CONJUNTOS ISOCRONOS DE SISTEMAS INVARIANTES.

    OpenAIRE

    VERA HURTADO, GUILLERMO FERNANDO

    2009-01-01

    La presente Tesis se enmarca dentro de la Teoría Matemática de Control. Específicamente, las herramientas utilizadas acá provienen de la teoría clásica de control [9], [25], [30] (capítulo 2), teoría dinámica de control [9] (capítulo 3) y teoría geométric 109p.

  9. Escenarios de la conflictividad: elecciones municipales en la Corona de Castilla afines del siglo XVII

    Directory of Open Access Journals (Sweden)

    Jesús BRAVO LOZANO

    2009-12-01

    Full Text Available RESUMEN: Las elecciones municipales en los pueblos de la Corona de Castilla hacen aflorar las tensiones propias de cualquier comunidad organizada. A finales del siglo XVII estas tensiones parecen agudizarse, o mostrarse por primera vez allí donde no eran patentes. Tal es el caso de Carrascosa del Campo (provincia de Cuenca. La pugna por el control del ayuntamiento y sus recursos enfrenta a dos familias, pero la realidad se encarga de redimensionar la pugna familiar convirtiéndola en una pugna política entre dos bandos, mucho más complejos que los entramados familiares. La violencia individual se recubre de política y provoca la intervención del Consejo de Castilla.ABSTRACT: Municipal elections in the villages of the Crown of Castile bring out the usual tensions of any organised community. Towards the end of the XVIIth century these tensions seem to become more acute, or else they surface for the first time in places where they had been latent. Such is the case of Carrascosa del Campo, in the province of Cuenca. Two families compete there for the control of the village council, but this dispute between families develops eventually into a political fight between factions of a complexity which goes considerably beyond that of family networks. Individual violence acquires a political colouring and provokes the intervention of the Council of Castile.

  10. Svoboda 'severnõh Afin' : derptskaja Polonia / Sergei Issakov, Pavel Sigalov

    Index Scriptorium Estoniae

    Issakov, Sergei, 1931-2013

    1997-01-01

    Korporatsioonist 'Polonia' (asut. 1828. a.) jt. poola üliõpilaste ühendustest Tartus. Tartu ülikoolis õppinud poola kirjanikest ja kirjandusteadlasest: Alfons Walicki, Aleksander Karol Groza, Edward Zheligowski, Bronislaw Zaleski, Jzef Bohdan Dzienkonski, Ludomir Gadon, Jzef Weyssenhoff, Marian Zdziechowski, Andrzej Niemojewski, Ludwik Bruner, Jerzy Jankowski

  11. Afinal, de que tradição eles estão falando?

    Directory of Open Access Journals (Sweden)

    Alexandre Hecker

    1998-01-01

    Full Text Available Após a queda do muro tem-se observado um constante e generalizado comportamento político de antigos membros da esquerda que agora tendem a admitir qualquer modelo ético-político como válido. Diante da vitória do pensamento neoliberal é importante conhecer a pluralidade de tradições que o socialismo desenvolveu entre nós, além de que, poder avaliar as idéias dos socialistas não-comunistas, têm servido para romper um limite a que nossos estudos políticos pareciam destinados: partia-se do princípio de que não houve no Brasil uma tradição intelectual de adesão às idéias democráticas. A história do pensamento político brasileiro parecia estar sempre marcada pelo autoritarismo.After the fall of the wall it has been observing a constant and widespread political behavior of old members of the left that now tend to admit any ethical-political model as valid. Before the victory of the neoliberal thought it is important to know the plurality of traditions that the socialism developed among us, in addition, to evaluate the no-communist socialists' ideas, they have been being good to break a limit the one that our political studies were destined: he broke of the beginning that there was not in Brazil an intellectual tradition of adhesion to the democratic ideas. The history of the Brazilian political thought seemed to be always marked by the autoritarism.

  12. O que se publica sobre comportamento do consumidor no Brasil, afinal?

    Directory of Open Access Journals (Sweden)

    Marcelo de Rezende Pinto

    2008-12-01

    Full Text Available This article aims to do an analysis of published articles on the topic behavior of the consumer using the principal vehicle for the dissemination of academic production in marketing in Brazil from 1997 to 2006. Based on the guidance proposed by Hoppen, Moreau and Lapointe (1997, were analyzed 238 articles by checking the use of basic elements of an investigation, concentrating on strategies and methodologies of research. After the tests on type of article, approach, nature of research, methodologies and searched segment of consumers, the study was conducted dividing up the articles into three categories: articles such survey, articles such trial and those based on qualitative research. It can be said that the main results of the study were: the finding of the preponderance of empirical work on the basis of positivist approach and use of traditional methods and techniques of quantitative research and data collection. It is important to observe a little concern of researchers with some relevant aspects of methodological quality. The article also presents ideas on new approaches that could be used to search the consumer and points that can contribute to the consolidation of the theme in Brazil.

  13. Afinal, quem é mesmo pedófilo? Who is really pedophile, after all?

    Directory of Open Access Journals (Sweden)

    Jane Felipe

    2006-06-01

    Full Text Available O presente artigo busca problematizar alguns dos aspectos pertinentes ao debate contemporâneo em torno das "novas" modalidades de experimentação dos desejos erótico-sexuais, em especial a pedofilia/o pedófilo, discutindo os modos pelos quais tais conceitos vêm sendo re-significados nos últimos anos. A partir do referencial teórico dos Estudos Culturais e dos Estudos de Gênero, numa abordagem pós-estruturalista de análise, pretendo mostrar que, apesar das tentativas de aprisionar/categorizar/ normatizar determinados comportamentos em torno da sexualidade, a partir de campos de conhecimento específicos, estes escorregam, escapam, vazam, nos sentidos que lhes são atribuídos.This article raises questions about some aspects of the contemporary debate concerning the "new" modes of experimenting erotic and sexual desires, especially pedophilia/the pedophile. It discusses the resignification of these concepts over the last years. The starting points are the Cultural Studies and the Gender Studies, in a post-structuralist analysis approach. I intend to show that, despite the attempts of confining/regulating/ categorizing certain behaviors regarding sexuality into specific fields of knowledge, they leak, slip, escape from the meanings attributed to them.

  14. Afinal, estão as empresas preparadas para a competência?

    Directory of Open Access Journals (Sweden)

    Zélia Miranda Kilimnik

    2005-06-01

    Full Text Available Este trabalho tem como objetivo apresentar os resultados de três pesquisas conduzidas com o propósito de investigar até que ponto a demanda por profissionais dotados de competências cada vez mais abrangentes e sofisticadas encontra-se acompanhada pela modernidade de políticas e práticas organizacionais que as sustentem. Utilizando como referencial teórico a abordagem de avaliação da modernidade organizacional (EBOLI, 1996 e a revisão das abordagens anglo-americana e francesa da competência, o estudo compreende a apresentação e análise comparativa de achados de três levantamentos empíricos de dados: um abrangendo 654 pós-graduandos em administração; outro envolvendo 220 pós-graduandos e egressos de programas de pós-graduação lato sensu na área de telecomunicações e um terceiro compreendendo 129 graduandos em administração. Após tratamento dos dados, por meio de técnicas estatísticas multivariadas e descritivas, constatou-se como principal resultado que a demanda por competências cada vez mais abrangentes e sofisticadas não tem sido acompanhada, em mesmo nível, pela modernidade de políticas e práticas de gestão, sugerindo a necessidade de ambientes organizacionais mais aderentes aos novos perfis profissionais requeridos.

  15. DDR y temas afines en el Plan de Desarrollo de Arauca 2012-2015

    OpenAIRE

    2013-01-01

    El Plan de Desarrollo de Arauca 2012-2015 se titula ‘Es Hora de Resultados’. Este se divide en tres capítulos. El primero es nombrado ‘Componente general’, y contiene: ‘Fundamentos del plan’; la ‘Visión Compartida Arauca 2032 Geoestratégica, Innovadora y Nuestra’; y ‘Arauca Frente a los Objetivos del Milenio –ODM’.

  16. Janelas de Flusser e Magritte. O que é, afinal, um webvídeo?

    Directory of Open Access Journals (Sweden)

    Suzana Kilpp

    2010-12-01

    Full Text Available O artigo introduz e articula a base conceitual aplicada em ‘Janelas de Flusser e Magritte’, um protótipo de navegação entre múltiplos vídeos através de um player, desenvolvido em parceria entre o Grupo de Pesquisa Audiovisualidades (GPAv e o Curso de Comunicação Digital (ComDig da Universidade do Vale do Rio dos Sinos (Unisinos. Apresenta e contextualiza princípios fundantes das audiovisualidades contemporâneas, em sua dimensão técnica, discursiva e cultural, relacionadas às teorias sobre imagens técnicas, de Vilém Flusser, e à condição humana, como foi tematizada no Surrealismo, em particular por René Magritte. Apresenta e justifica uma base conceitual, em construção, sobre a comunicação digital, com especial atenção a formatos para dispositivos móveis. Apresenta criticamente o processo de elaboração do protótipo e dos vídeos componentes e faz apontamentos para a pesquisa na área. 

  17. Svoboda 'severnõh Afin' : derptskaja Polonia / Sergei Issakov, Pavel Sigalov

    Index Scriptorium Estoniae

    Issakov, Sergei, 1931-2013

    1997-01-01

    Korporatsioonist 'Polonia' (asut. 1828. a.) jt. poola üliõpilaste ühendustest Tartus. Tartu ülikoolis õppinud poola kirjanikest ja kirjandusteadlasest: Alfons Walicki, Aleksander Karol Groza, Edward Zheligowski, Bronislaw Zaleski, Jzef Bohdan Dzienkonski, Ludomir Gadon, Jzef Weyssenhoff, Marian Zdziechowski, Andrzej Niemojewski, Ludwik Bruner, Jerzy Jankowski

  18. Diversity and biogeography of neotropical bamboos (Poaceae: Bambusoideae Diversidade e biogeografia de bambus (Poaceae: Bambusoideae

    Directory of Open Access Journals (Sweden)

    Lynn G Clark

    1990-07-01

    Full Text Available The present paper analyses the distribution of bamboos in New World. For convenience, bamboos are divided into two broad groups, the woody bamboos and the herbaceous bamboos. These categories do not necessarily reflect phylogenetic relationships among bamboo groups. The Bambuseae includes all of the woody bamboos and is probably monophyletic, whereas the herbaceous bamboos are classified into eight tribes. In the New World (including underscribed taxa, 45-46 genera and approximately 515 species are represented; only two genera: Arundinaria and Streptogyna are not exclusively neotropical. The area of greatest endemism and diversity is the humid coastal forests of Bahia, Brazil. 22 genera have been found in this relatively small area, representing 48% of all New World genera. Five of the 22 genera are endemic to the Bahia coastal forests.O presente trabalho analisa a distribuição geográfica dos bambus do Novo Mundo. Por questões práticas, os bambus foram divididos em dois grupos: os bambus lenhosos e os herbáceos, essas categorias entretanto, nem sempre refletem relacionamentos filogenéticos, pois embora as Bambuseae incluam todos os bambus lenhosos, sendo portanto provavelmetne monofiléticos, os bambus herbáceos são classificados em oito tribos. No Novo Mundo, (incluindo os taxa ainda não descritos existem cerca de 45-46 gêneros e aproximadamente 515 espécies. Desses gêneros, apenas dois: Arundinaria e Streptogyna não são exclusivamente neotropicais. A área de maior endemismo e diversidade do grupo, está nas florestas costeiras da Bahia, Brasil. Nesta região são encontrados 22 gêneros, representando 48% de todos os gêneros neotropicais e desses, 5 são exclusivos desta região da Bahia.

  19. Морфологические особенности пыльцевых зёрен некоторых родов злаковых (Poaceae Barnhart. )

    OpenAIRE

    Пунсалпаамуу, Г.; Гэгээнсувд, Ц.; Менхзул, Т.; Золбаяр, Д.; Сайндовдон, Д.; Сангидорж, Б.

    2012-01-01

    Описание морфологии пьшьцевых зерен производится с использованием методов Erdtman /1948/, Куприянова /1948/, Punsalpaamuu /1999/. В том числе исследованы форма, размер, апертура, экзина и поверхностные структуры 31 вида из 14 родов семейства Poaceae (Bamhart.).

  20. 青藏高原东缘30种禾本科植物种子萌发对光的响应及其与生活史的关联%Germination response to light of 30 Poaceae species from the eastern Qinghai-Tibet plateau and correlates with their life history

    Institute of Scientific and Technical Information of China (English)

    张莹莹; 张春辉; 张蕾; 吕俊平; 王晨阳; 卜海燕; 杜国祯

    2011-01-01

    Three different light intensities of artificial shade were set under natural conditions and the effects of light intensity on seed germination of 30 Poaceae plants from the eastern Qinghai-Tibet plateau were observed. The results of one-way ANOVA showed that under different light intensities no significant difference existed in the germination percentage, but the mean germination time had significant difference. Light only influenced the process of germination. Seeds would expedite the process of germination to improve their fitness in a competitive environment. Under each light intensity, the germination percentage of perennials was significantly higher than that of annuals, but the mean germination time showed no significant difference between two life forms. The difference of germination between two life form plants was based on quantity. The findings indicated an intrinsic association between seed germination and life form. The mean germination time of neither annuals nor perennials increased with decreasing light intensity; however, the mean germination time of perennials increased more quickly than that of annuals. Seeds of annuals were more sensitive to light intensity than perennial seeds and made better use of this unique opportunity. In a word, under different light intensities plants would choose the best germination strategy to increase their fitness. The best germination strategy is greatly different betweenannuals and perennias and this difference can be attributed to their different reproducing strategies.%在野外自然条件下设置三个不同光照强度的人工遮阴对青藏高原东缘30种不同生活型禾本科植物种子的萌发行为进行了研究.结果表明:各光照梯度下30种禾本科植物种子的萌发率差异不显著,平均萌发时间差异显著,外在环境因子光照主要影响植物种子萌发的进程.植物在存在竞争的环境中会选择快速萌发来争取幼苗茎杆伸长开始的时间,以截获更

  1. Genomic homeology between Pennisetum purpureum and Pennisetum glaucum (Poaceae

    Directory of Open Access Journals (Sweden)

    Gabriela Barreto dos Reis

    2014-08-01

    Full Text Available The genus Pennisetum (Richard, 1805 includes two economically important tropical forage plants: Pennisetum purpureum (Schumacher, 1827 (elephant grass, with 2n = 4x = 28 chromosomes and genomes A'A'BB, and Pennisetum glaucum (Linnaeus, 1753 (pearl millet, with 2n = 2x = 14 chromosomes and genomes AA. The genetic proximity between them allows obtaining hybrids (2n = 3x = 21 that yield forage of higher quality in relation to the parents. The study of genomic relationships provides subsidies for the knowledge about phylogenetic relations and evolution, and is useful in breeding programs seeking gene introgression. Concerning elephant grass and pearl millet, the homeology between the genomes A and A', and between these and the genome B, has been reported by conventional cytogenetic techniques. The objective of the present study was to demonstrate the degree of homeology between these genomes by means of genomic in situ hybridization (GISH. The results confirmed the homeology between the genomes A of pearl millet and A'B of elephant grass, and showed that there are differences in the distribution and proportion of homologous regions after hybridization. Discussion regarding the evolutionary origin of P. purpureum and P. glaucum was also included.

  2. Phylogenetic origin of Beckmannia (Poaceae) inferred from molecular evidence

    Institute of Scientific and Technical Information of China (English)

    Chong-Mei XU; Chang-You QU; Wen-Guang YU; Xue-Jie ZHANG; Fa-Zeng LI

    2009-01-01

    The phylogenetic origin of Beckmannia remains unknown. The genus has been placed within the Chlorideae, Aveneae (Agrostideae), Poeae, or treated as an isolate lineage, Beckmanniinae. In the present study, we used nuclear internal transcribed spacer (ITS) and chloroplast trnL-F sequences to examine the phylogenetic relationship between Beckmannia and those genera that have assumed to be related. On the basis of the results of our studies, the following conclusions could be drawn: (i) Beckmannia and Alopecurus are sister groups with high support; and (ii) Beckmannia and Alopecurus are nested in the Poeae clade with high support. The results of our analysis suggest that Beckmannia should be placed in Poeae.

  3. Sources of gene tree discordance on oryza (poaceae) chromosome 3

    Science.gov (United States)

    We describe new methods for characterizing gene tree discordance in phylogenomic datasets, which screen for deviations from neutral expectations, summarize variation in statistical support among gene trees, and allow comparison of the patterns of discordance induced by various analysis choices. Usin...

  4. Genome Relationship between Psathyrostachys huashanica and P. fragilis (Poaceae)

    DEFF Research Database (Denmark)

    Bothmer, R. Von; Kotimäki, M.; Linde-Laursen, I.

    1987-01-01

    Hybrids between the Chinese endemic species Psathyrostachys huashanica KENG and the SW. Asian species P. fragilis (BOISS.) NEVSKI (all 2n = 14) developed normally but were completely sterile. Meiotic analyses revealed a high chiasma frequency indicating that the two species as well as P. juncea (...

  5. Cercosporoid fungi (Mycosphaerellaceae) 3. Species on monocots (Poaceae, true grasses)

    NARCIS (Netherlands)

    Braun, Uwe; Crous, Pedro W; Nakashima, Chiharu

    The third part of a series of monographic treatments of cercosporoid fungi (formerly Cercospora s. lat., Mycosphaerellaceae, Ascomycota) continues with a treatment of taxa on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), covering asexual and holomorph species with mycosphaerella-like

  6. Ecological genetics of floret mass variation in Bromus tectorum (Poaceae)

    Science.gov (United States)

    Susan E. Meyer

    2010-01-01

    Bromus tectorum L. (cheatgrass, downy brome) is a highly invasive inbreeding annual grass that dominates millions of hectares of former shrubland in interior western North America. Factors contributing to its success include strong genetic regulation of key adaptive traits coupled with high phenotypic plasticity in response to resource availability (Meyer and Allen...

  7. Three New Teosintes (Zea spp., Poaceae) From Mexico

    Science.gov (United States)

    The discovery of new species of teosinte from México motivated the comparative study of populations from México, Guatemala and Nicaragua through detailed ecogeographic, morphologic, cytogenetic and molecular characterization. The study involved a comparative analysis of morphological, ecogeographic,...

  8. A new species of Merxmuellera (Arundineae, Poaceae from South Africa

    Directory of Open Access Journals (Sweden)

    N. P. Barker

    1991-12-01

    Full Text Available Merxmuellera setacea N.P. Barker from the south-western Cape. South Africa, is formally described. Descriptions of the morphology and leaf anatomy, in transectional and surface view, as observed under the light- and scanning electron microscope are given. Comparisons between this taxon and other southern African arundinoid species are made on the basis of morphological and anatomical observations. While the morphology of M setacea is in keeping with the generic limits of Merxmuellera Conert. the leaf blade anatomy appears to be intermediate between Merxmuellera, Pentameris Beauv. and  Pentaschistis (Nees Spach.

  9. Numerical taxonomy of Stipa (Poaceae) species in Iran.

    Science.gov (United States)

    Sheidai, Masoud; Attaei, Saeideh; Khosravi-Reineh, Masoomeh

    2007-02-15

    Numerical taxonomic studies were performed on 57 populations of 15 Stipa species belonging to 5 different sections, concerning intra-population and inter-populations variations as well as inter-specific relationships. The most variable morphological characters useful in the species delimitation were also determined. The species studied also differed significantly in most of the quantitative characters studied and the mean of such characters may be of use in the species delimitation. The clustering showed distinctness of the species studied as the populations of each species are placed close to each other and separate from the other species.

  10. A population genetic transect of Panicum hallii (Poaceae).

    Science.gov (United States)

    Lowry, David B; Purmal, Colin T; Juenger, Thomas E

    2013-03-01

    Understanding the relationship between climate, adaptation, and population structure is of fundamental importance to botanists because these factors are crucial for the evolution of biodiversity and the response of species to future climate change. Panicum hallii is an emerging model system for perennial grass and bioenergy research, yet very little is known about the relationship between climate and population structure in this system. • We analyzed geographic population differentiation across 39 populations of P. hallii along a longitudinal transect from the savannas of central Texas through the deserts of Arizona and New Mexico. A combination of morphological and genetic (microsatellite) analysis was used to explore patterns of population structure. • We found strong differentiation between high elevation western desert populations and lower elevation eastern populations of P. hallii, with a pronounced break in structure occurring in western Texas. In addition, we confirmed that there are high levels of morphological and genetic structure between previous recognized varieties (var. hallii and var. filipes) within this species. • The results of this study suggest that patterns of population structure within P. hallii may be driven by climatic variation over space. Overall, this study lays the groundwork for future studies on the genetics of local adaptation and reproductive isolation in this system.

  11. External fruit morphology of southern African Arundineae (Arundinoideae: Poaceae

    Directory of Open Access Journals (Sweden)

    N. P. Barker

    1994-12-01

    Full Text Available Fruits of a number of taxa of all indigenous southern African arundinoid genera were examined by means of SEM. Size, shape, compression, surface sculpturing, embryo anti hilum features were recorded and fruits of all genera are illustrated. Results are compared to existing descriptions. The genera are placed in five informal groups according to similarities noted in the fruits.

  12. Tolerance of wheat (Poales: Poaceae) seedlings to wireworm (Coleoptera: Elateridae).

    Science.gov (United States)

    Higginbotham, Ryan W; Froese, Paul S; Carter, Arron H

    2014-04-01

    Wireworms (Coleoptera: Elateridae), the subterranean larval stage of the click beetle, are becoming more prevalent in many cropping systems and posing an increasing economic threat to wheat growers in the Pacific Northwest following the cancellation of the insecticide lindane in 2006. Current insecticide seed treatments alone are not adequate for wireworm control. The objective of this study was to evaluate a diverse set of 163 wheat genotypes for tolerance to wireworm feeding. Entries were planted in replicated field trials over 3 yr and evaluated for their performance when grown in the presence of wireworms. Entries were rated based on survival and given a tolerance score. Results indicated that differences exist among wheat genotypes in their level of tolerance to wireworm feeding. In particular, consistently high-ranking genotypes of interest may be 'BR 18', 'Sonalika', 'Safed Lerma', and 'Hollis'. These genotypes, used in conjunction with other cultural or chemical control methods, may help provide an economic means of controlling wireworms.

  13. Taxonomy, Variation, and Relationships in the Hordeum parodii Group (Poaceae)

    DEFF Research Database (Denmark)

    Von Bothmer, R.; Jacobsen, N.; Bagger Jørgensen, Rikke

    1986-01-01

    The Hordeum parodii group contains three species, viz. H. parodii Covas (6x), H. tetraploidum Covas (4x), and H. fuegianum Bothmer, Jacobsen, et Jorgensen, sp. nov. (4x). The former two species mainly occur in C and S Argentina, while H. fuegianum is native to Tierra del Fuego. All three species ...

  14. REVISIÓN DE PASPALUM GRUPO GARDNERIANA (POACEAE, PASPALEAE

    Directory of Open Access Journals (Sweden)

    Marcela V. Nicola

    2014-01-01

    Full Text Available El presente tratamiento incluye una revision taxonómica de las especies de Paspalum grupo Gard - neriana. Dentro de este grupo se consideran siete especies, caracterizadas por incluir plantas anuales o perennes, con espiguillas usualmente obovoides, gluma superior ausente o reducida y antecio superior endurecido y marcadamente papiloso, con papilas verrugosas en toda su superficie. Se incluye una clave de las especies, descripciones, ilustraciones y fotos de los antecios, junto con un análisis de la relación del grupo dentro del género Paspalum . Se consideran dentro del grupo las siguientes especies: Paspalum burchellii, P. delicatum, P. gardnerianum, P. nudatum, P. pictum, P. reduncum y P. subsesquiglume . Se designan lectotipos para P. burchellii, P. connectens, P. reduncum y P. subsesquiglume ; P. gemmosum es sinónimo de P. subsesquiglume.

  15. Freeze tolerance differs between two ecotypes of Paspalum vaginatum (Poaceae

    Directory of Open Access Journals (Sweden)

    Liliana Teresa Fabbri

    2016-03-01

    Full Text Available Morphological and physiological responses to freezing were evaluated in two ecotypes of the perennial turfgrass Paspalum vaginatum. Leaf extension rate, number of active meristems, leaf water potential and net photosynthesis were measured on plants of both a commercial cultivar, 'Sea Isle 2000', and a wild ecotype from the Flooding Pampa grasslands of Argentina. Plants were propagated by cloning, cultivated in pots, and examined during 18 consecutive days under two treatments: a non-frozen control treatment (15.5±7 ºC and a frozen treatment with two stages: Stage 1 with four hours of freezing stress for 10 nights (-5ºC, and Stage 2 with 12 hours of freezing stress for eight nights (five nights at -5ºC and three nights at -8ºC. After these treatments, plants were returned to the outside environment to evaluate shoot injury and post-freezing recovery. Leaf water potential, net photosynthesis and leaf extension rate were significantly higher in the wild ecotype than in the commercial cultivar. Meristem density was reduced after freezing in both ecotypes, but was more pronounced in the commercial cultivar (98.5% than in the wild ecotype (80%. Thus, the two ecotypes coming from different environments, exhibited different morphological and physiological responses to exposure to freezing temperatures.

  16. A study on the genus Digitaria (Poaceae in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Amini Rad

    2015-10-01

    Full Text Available In current research, the genus Digitaria has been studied in Iran. As a results, D. ischaemum, D. sanguinalis, D. sabulosa, D. ciliaris, D. nodosa with D. violascens which is reported for the first time from Iran here, are confirmed for the flora of Iran. In addition, the record of D. stricta from Iran is rejected as referable to D. violascens after the studying their specimens. Finally, a key to all species of the genus Digitaria in Iran along with morphological descriptions of species are provided.

  17. LAS ESPECIES DE MUHLENBERGIA (POACEAE: CHLORIDOIDEAE DE ARGENTINA

    Directory of Open Access Journals (Sweden)

    Peterson Paul

    2011-06-01

    Full Text Available Se presenta un estudio taxonómico de las especies nativas argentinas del géneroMuhlenbergia, basado en el análisis de los especímenes depositados en 48 herbarios.Se analizan diversos aspectos relativos a la clasifi cación, la nomenclatura y lavariación morfológica de los caracteres. Muhlenbergia está representado enArgentina por 18 especies nativas. Se proporcionan claves para reconocer lasespecies presentes en el país, así como también descripciones de éstas, sinónimos,ilustraciones, distribución geográfica y algunos comentarios morfológicos yecológicos. Muhlenbergia breviaristata (Hack. Parodi y Muhlenbergia holwayorumHitchc., se reducen como sinónimos del híbrido Muhlenbergia angustata (J. PreslKunth × M. rigida (Kunth Kunth. Muhlenbergia diversiglumis Trin. se cita porprimera vez para la Argentina. Por otra parte, las especies Muhlenbergia tenella(Kunth Trin. y Muhlenbergia tenuissima (J. Presl Kunth se excluyen de la fl orade Argentina.

  18. Multigenic phylogeny and analysis of tree incongruences in Triticeae (Poaceae

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    Guilhaumon Claire

    2011-06-01

    Full Text Available Abstract Background Introgressive events (e.g., hybridization, gene flow, horizontal gene transfer and incomplete lineage sorting of ancestral polymorphisms are a challenge for phylogenetic analyses since different genes may exhibit conflicting genealogical histories. Grasses of the Triticeae tribe provide a particularly striking example of incongruence among gene trees. Previous phylogenies, mostly inferred with one gene, are in conflict for several taxon positions. Therefore, obtaining a resolved picture of relationships among genera and species of this tribe has been a challenging task. Here, we obtain the most comprehensive molecular dataset to date in Triticeae, including one chloroplastic and 26 nuclear genes. We aim to test whether it is possible to infer phylogenetic relationships in the face of (potentially large-scale introgressive events and/or incomplete lineage sorting; to identify parts of the evolutionary history that have not evolved in a tree-like manner; and to decipher the biological causes of gene-tree conflicts in this tribe. Results We obtain resolved phylogenetic hypotheses using the supermatrix and Bayesian Concordance Factors (BCF approaches despite numerous incongruences among gene trees. These phylogenies suggest the existence of 4-5 major clades within Triticeae, with Psathyrostachys and Hordeum being the deepest genera. In addition, we construct a multigenic network that highlights parts of the Triticeae history that have not evolved in a tree-like manner. Dasypyrum, Heteranthelium and genera of clade V, grouping Secale, Taeniatherum, Triticum and Aegilops, have evolved in a reticulated manner. Their relationships are thus better represented by the multigenic network than by the supermatrix or BCF trees. Noteworthy, we demonstrate that gene-tree incongruences increase with genetic distance and are greater in telomeric than centromeric genes. Together, our results suggest that recombination is the main factor decoupling gene trees from multigenic trees. Conclusions Our study is the first to propose a comprehensive, multigenic phylogeny of Triticeae. It clarifies several aspects of the relationships among genera and species of this tribe, and pinpoints biological groups with likely reticulate evolution. Importantly, this study extends previous results obtained in Drosophila by demonstrating that recombination can exacerbate gene-tree conflicts in phylogenetic reconstructions.

  19. Taxonomy, Variation, and Relationships in the Hordeum parodii Group (Poaceae)

    DEFF Research Database (Denmark)

    Von Bothmer, R.; Jacobsen, N.; Bagger Jørgensen, Rikke

    1986-01-01

    The Hordeum parodii group contains three species, viz. H. parodii Covas (6x), H. tetraploidum Covas (4x), and H. fuegianum Bothmer, Jacobsen, et Jorgensen, sp. nov. (4x). The former two species mainly occur in C and S Argentina, while H. fuegianum is native to Tierra del Fuego. All three species...

  20. Micropropagation of Guadua angustifolia Kunth (Poaceae) using a ...

    African Journals Online (AJOL)

    Universidad del Quindio

    2016-07-13

    Jul 13, 2016 ... Vessels of both treatments were autoclaved at 121°C at 15 psi, using RITA® ..... Aspectos sobre la distribución y la ecología de los bambúes de ... Academia Brasileira de Ciencias, Rio de Janeiro, Pp. 121-157. Sood A, Ahuja ...

  1. Notes on Aegilops cylindrica (Triticeae, Poaceae in Iran

    Directory of Open Access Journals (Sweden)

    Sayed Zabihollah Hosseini

    2015-01-01

    Full Text Available The present paper deals with the study of the taxonomy of one hundred accessions of Aegilops cylindica collected all around the country, and also Iranian materials and type specimens and related species housed in the Natural History Museum Vienna (W, the Botanic Garden and Botanical Museum Berlin (B, were studied morphologically. The results showed that morphological traits such as length of spike, length of awn, number of spikelet in each spike, presence/absence of hair on spikelets and rachis were highly variable among the studied materials. Based on the results of this study A. cylindica was recognized as having three varieties, all new records, for Iran.

  2. Meiotic chromosome behaviour in Cenchrus ciliarisPoaceae: Panicoideae

    Directory of Open Access Journals (Sweden)

    N. C. Visser

    1998-12-01

    Full Text Available A basic chromosome number of x = 9 has been confirmed for Cenchrus ciliaris L. Polyploidy is common and levels vary from tetraploid to hexaploid. Aneuploidv is reported for a single specimen, where two chromosomes of a single genome were lost. Various meiotic irregularities were observed. The highest incidence of meiotic abnormalities was observed in the pentaploid specimens. This was attributed to their uneven polyploid level All specimens varied from segmental alloploid to alloploid.

  3. Positional cloning in maize (Zea mays subsp. mays, Poaceae)1

    Science.gov (United States)

    Gallavotti, Andrea; Whipple, Clinton J.

    2015-01-01

    • Premise of the study: Positional (or map-based) cloning is a common approach to identify the molecular lesions causing mutant phenotypes. Despite its large and complex genome, positional cloning has been recently shown to be feasible in maize, opening up a diverse collection of mutants to molecular characterization. • Methods and Results: Here we outline a general protocol for positional cloning in maize. While the general strategy is similar to that used in other plant species, we focus on the unique resources and approaches that should be considered when applied to maize mutants. • Conclusions: Positional cloning approaches are appropriate for maize mutants and quantitative traits, opening up to molecular characterization the large array of genetic diversity in this agronomically important species. The cloning approach described should be broadly applicable to other species as more plant genomes become available. PMID:25606355

  4. El espanol familiar y zonas afines--ensayo bibliografico: 26 (Colloquial Spanish and Related Areas--Bibliographic Essay: 26)

    Science.gov (United States)

    Polo, Jose

    1975-01-01

    Discusses the study of colloquial Spanish in literary texts. Presents an annotated list of Spanish colloquial expressions extracted from "Paralelo 40" by Jose Luis Castillo-Puche. (Text is in Spanish.) (TL)

  5. O computador e a construção de sentido ou o computador: afinal, o que é isso?

    OpenAIRE

    Hofmeister de Aguiar, Rafael; Unisinos; Moraes de Fraga, Dinorá; Unisinos

    2011-01-01

    Abstract : This paper proposes to conduct a theoretical construct about the formation of meaning in texts in digital environments. In this way, it proposes the initial reflection presenting the esthesic involvement of the subject as the constitutor element of meaning in the digital environment. Another aspect that is presented as an initial hypothesis of sense in this context is the element paratextual. For an initial questioning, it started from a theoretical basis (Flusser, Johnson, Genette...

  6. CONCEPCIONES SOBRE EDUCACIÓN AMBIENTAL DE DOCENTES DE PROGRAMAS DE LICENCIATURA EN EDUCACIÓN AMBIENTAL O AFINES

    Directory of Open Access Journals (Sweden)

    Fabiola Cuéllar Caicedo

    2006-01-01

    Full Text Available Esta investigación abordó las concepciones que sobre educación ambiental tienen los docentes universitarios que forman educadores en el área de educación ambiental en las diferentes universidades de Colombia. Ello mediante un enfoque cuali-cuantitativo, estructurando unas herramientas confiables cuyos resultados nos permitieron conocer que los docentes identifican comúnmente la educación ambiental con la ecología, con el medio ambiente, y más allá, la confunden con los PRAES; además no aplican la estructura transversal en los currículos, sino que la toman como una asignatura o un tema más de la asignatura de ciencias naturales o biología. Esto nos indicó que los docentes poseen diversas concepciones, en muchos casos erradas, sobre la educación ambiental. Como resultado de esta investigación se destaca la necesidad de que los docentes reflexionen y si es posible transformen las concepciones y la aplicación de la educación ambiental.

  7. Un grupo de poder afines de la Edad Media: los canónigos de la catedral de Toledo

    Directory of Open Access Journals (Sweden)

    Lop Otín, María José

    2005-12-01

    Full Text Available A través de este artículo mostramos la importancia de los Canónigos de la Catedral de Toledo en el siglo XV. Éstos constituían un influyente grupo de poder por su pertenencia a familias principales, su peso económico y alto tren de vida, su superior nivel cultural y los numerosos privilegios acumulados. Al final incluimos la lista de sus nombres.

  8. Review of xenon-133 production and related problems; Estudio bibliografico de la produccion de xenon-133 y problemas afines

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina, M.; Ropero, M.

    1980-07-01

    A literature survey is given on the production methods of fission xenon-133 and related problems, such as purification, metrological and dosimetric aspects, preparation of isotopic solutions, recycling, etc. 127 references are included. (Author) 127 refs.

  9. Alterações espirométricas em doenças obstrutivas: afinal, o quanto é relevante?

    Directory of Open Access Journals (Sweden)

    André Luis Pinto Soares

    2013-02-01

    Full Text Available OBJETIVO: Estabelecer os limites superiores para mudanças em VEF1, capacidade vital lenta (CVL, CVF e capacidade inspiratória (CI após o uso de placebo em pacientes com obstrução ao fluxo aéreo. MÉTODOS: Cento e dois adultos com obstrução ao fluxo aéreo (VEF1 = 62 ± 19% do previsto foram incluídos neste estudo. Todos os participantes realizaram manobras de CVL e CVF antes e depois do uso de spray de placebo. As mudanças em VEF1, CVL, CVF e CI foram expressas em valores absolutos, porcentagem de variação em relação aos valores basais e porcentagem dos valores previstos, e foram calculados os IC95% e os percentis 95. A análise fatorial foi realizada a fim de determinar como essas alterações se agrupavam. RESULTADOS: Considerando os IC95% e percentis 95 e após o arredondamento dos valores, obtivemos os seguintes limites superiores para resposta significante: VEF1 = 0,20 L, CVF = 0,20 L, CVL = 0,25 L e CI = 0,30 L (em valores absolutos; VEF1 = 12%, CVF = 7%, CVL = 10% e CI = 15% (em porcentagem de variação em relação aos valores basais e VEF1 = 7%, CVF = 6%, CVL = 7% e CI = 12% (em porcentagem dos valores previstos. CONCLUSÕES: Em pacientes com obstrução ao fluxo aéreo, a CI apresenta maior variabilidade do que a CVF e a CVL. Para a CI, valores maiores que 0,30 L e 15% de variação em relação ao valor basal devem ser considerados significantes. Para CVF, valores maiores que 0,20L e 7% de variação em relação ao valor basal são significantes. Alternativamente, alterações de mais de 0,20 L e 7% do previsto no VEF1 e na CVF devem ser consideradas significantes. Na análise fatorial, os parâmetros espirométricos se agruparam em três dimensões, expressando mudanças no fluxo, volume e hiperinsuflação dinâmica.

  10. Notas sobre escrofulariáceas de Colombia: I. - Nueva especie de Buchnera afin A B. Rubriflora Philcox

    Directory of Open Access Journals (Sweden)

    Fernández Soto José Luis

    1986-12-01

    Full Text Available Se describe una nueva especie de Buchnera que presenta pilosidad glandular, la única entre las especies americanas del género y próxima a  B. rubriflora Philcox. Se aportan nuevos datos sobre la distribución y variabilidad de esta última, comentando finalmente la relación entre ambos táxones.  Al revisar las escrofulariáceas del Herbario Nacional Colombiano (COL, se tuvo la oportunidad de estudiar una serie de colecciones del género Buchnera, que son el objeto de esta primera nota sobre escrofulariáceas colombianas. Aparte de la localización de nuevos registros de B. rubriflora, que amplían la distribución conocida de la especie y otras puntualizaciones relativas a su parentesco y ecología; sin duda el dato más interesante lo aportó el estudio de unas plantas procedentes del sur de la Sierra de La Macarena (Depto. del Meta, que presentan indumento glandular, mezclado con pilosidad más corta no glandular. Este carácter único conocido hasta ahora en las buchneras americanas, permite describir esta planta como nueva. Este nuevo taxon está morfológicamente relacionado con B. rubriflora, con la que comparte además y con carácter exclusivo en las especies americanas la coloración roja de sus corolas. Se hacen por último algunos comentarios sobre este pequeño grupo de buchneras, del que probablemente falte aún mucho por conocer en cuanto a distribución y diversidad, por la falta de muestreo en amplios territorios colombianos ecológica y geológicamente similares a los enclaves hasta ahora conocidos para estos táxones.

  11. Feasibility of Implementing an Early Intervention Program in an Urban Low-Income Setting to Improve Neurodevelopmental Outcome in Survivors Following Birth Asphyxia Faisabilité de mise en œuvre d'un Programme d'Intervention Précoce dans les milieux urbains à faibles revenus afin d'améliorer le résultat neurodéveloppemental chez les enfants survivant à une asphyxie à la naissance Viabilidad de la aplicación de un Programa de Intervención Precoz en un entorno urbano de bajos ingresos para mejorar el neurodesarrollo en los supervivientes luego de un cuadro de asfixia perinatal

    Directory of Open Access Journals (Sweden)

    Elwyn Chomba

    2011-08-01

    une étude de soins standard ou un EIP. Les couples mère/bébé ont été randomisés dans des groupes témoins (soins standard et d'intervention (EIP, et ont été suivis à domicile sur une base bihebdomadaire/bimensuelle, de l'âge de 8 semaines à l'âge de 8 mois. Quarante-deux couples mère/bébé (52,5 % ont terminé l'étude à 8 mois. Les raisons du non-achèvement de cette étude sont les suivantes : 19 (50,1 % ont été perdus de vue, 16 (42,1 % ont abandonné et 3 (7,8 % sont décédés. Le suivi jusqu'à l'âge de 8 mois n'était pas réalisable pour la majorité des femmes dans une grande ville ayant une population à faibles revenus. Ainsi, pour les enfants ayant souffert d'une asphyxie à la naissance, les interventions nécessitant des visites de soins supplémentaires peuvent ne pas être réalisables dans le milieu testé. Il est donc nécessaire de conduire d'autres études EIP afin de déterminer les moyens d'amélioration des taux de suivi des enfants survivant à une asphyxie à la naissance. L'intégration de programmes d'intervention précoce à d'autres programmes de santé donnant de bons résultats, comme les programmes d'immunisation existants, pourra peut-être améliorer les taux de suivi.La asfixia perinatal es una de las principales causas de mortalidad neonatal (23%. Un programa de intervención precoz (EIP, por sus siglas en inglés podría mejorar el neurodesarrollo en los supervivientes de este cuadro, pero aún no se ha demostrado su viabilidad en países de bajos ingresos. En este estudio piloto llevado a cabo en Zambia, en el que se analizó la atención estándar y un EIP, participaron ochenta recién nacidos con un peso mínimo de 1.500 gramos que sufrieron asfixia perinatal y fueron reanimados con bolsa y mascarilla. Las parejas de madres y bebés fueron atendidas aleatoriamente en grupos de control (cuidados habituales e intervención (EIP y se les hizo un seguimiento bisemanal/quincenal  a domicilio desde las 8 semanas

  12. Vegetation types and climate conditions reflected by the modern phytolith assemblages in the subalpine Dalaoling Forest Reserve, central China

    Science.gov (United States)

    Traoré, Djakanibé Désiré; Gu, Yansheng; Liu, Humei; Shemsanga, Ceven; Ge, Jiwen

    2015-06-01

    This research describes modern phytolith records and distributions from subalpine surface soils in the Dalaoling Forest Reserve, and reveals its implications for local climate conditions with respect to the altitude gradient. Well-preserved phytolith morpho-types, assemblages, and climatic indices were used to study the relationship between local vegetation and climate conditions. The phytolith classification system is mainly based on the characteristics of detailed morpho-types described for anatomical terms, which are divided into seven groups: long cells, short cells, bulliform cells, hair cells, pteridophyte type, broad-leaved type, and gymnosperm type. Phytoliths originating from the Poaceae are composed of Pooideae (rondel and trapeziform), Panicoideae (bilobate, cross, and polylobate), Chloridoideae (short/square saddle), and Bambusoideae (oblong concave saddle). Based on the altitudinal distribution of the phytolith assemblages and the indices of aridity (Iph), climate (Ic), and tree cover density (D/P), five phytolith assemblage zones have revealed the five types of climatic conditions ranging from 1,169 m to 2,005 m in turn: warm-wet, warm-xeric to warm-mesic, warm-xeric to cool-mesic, cool-xeric, and cool-mesic to cool-xeric. The Bambusoideae, Panicoideae, and Chloridoideae are the dominant vegetation at the lower-middle of the mountains, while Pooideae is mainly distributed in the higher mountains. The close relationship between phytolith assembleages and changes of altitude gradient suggest that vegetation distribution patterns and plant ecology in the Dalaoling mountains are controlled by temperature and humidity conditions. Our results highlight the importance of phytolith records as reliable ecoclimatic indicators for vegetation ecology in subtropical regions.

  13. Asignación sistemática y paleocomunidades inferidas a partir del estudio fitolítico de sedimentos cuaternarios de Entre Ríos, Argentina Systematic assignation and paleocommunities inferred by a phytolite study of quaternary sediments from Entre Ríos, Argentina

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    Georgina Erra

    2010-12-01

    Full Text Available El análisis de los fitolitos es una de las disciplinas paleobotánicas utilizadas para la reconstrucción de ecosistemas pasados ya que proporcionan un registro preciso de una parte de la vegetación, en áreas concretas y en un momento determinado. Teniendo en cuenta la importancia de estos análisis se estudió la composición y variabilidad fitolítica de los sedimentos loéssicos cuaternarios de la Formación Tezanos Pinto en el sudoeste de la provincia de Entre Ríos. Los datos de base obtenidos permitieron caracterizar la paleocomunidad existente al momento de depositación de los sedimentos loéssicos. Las formas encontradas corresponden tanto a microfitolitos como a macrofitolitos, siendo del tipo bilobados y polilobados (asignables a gramíneas de la subfamilia Panicoideae, tipo saddle (subfamilia Chloridoideae y tipo cónico o rondel (subfamilia Pooideae. También fueron hallados fitolitos provenientes de pelos, aguijones y ganchos, de células buliformes y de células largas (todos tipos celulares de origen epidérmico de gramíneas sin capacidad diagnóstica para diferenciar subfamilias, y otros producidos por taxones no graminoides (esféricos equinados provenientes de la familia Arecaceae.Phytolith analysis is one of the paleobotanic disciplines used for the reconstruction of past ecosystems, because they provide a precise record of part of the vegetation for a specific time and place. In this context, the composition and variability of phytoliths in Quaternary loessic sediments from the Tezanos Pinto Formation in southwestern Entre Ríos province was studied. The data obtained allowed characterizing the paleocommunity that existed at the time when the loessic sediments were deposited. The found forms correspond to microphytoliths and to macrophytoliths, being of the bilobate and polylobate type (described for Poaceae subfamily Panicoideae, saddle type (subfamily Chloridoideae and conical or rondel type (subfamily Pooideae. Also

  14. Distribution and evolutionary dynamics of Stowaway Miniature Inverted repeat Transposable Elements (MITEs) in grasses.

    Science.gov (United States)

    Minaya, Miguel; Pimentel, Manuel; Mason-Gamer, Roberta; Catalan, Pilar

    2013-07-01

    The occurrence of Stowaway MITEs and their potential footprints in the grasses was assessed within an explicit phylogenetic framework. An organismal tree was used to analyze the distribution and evolutionary dynamics of these elements and their potential excision footprints in the fourth intron of the β-amylase gene and in other introns of several nuclear genes across the Poaceae. Megablast and discontiguous megablast searches in the Entrez nucleotide database were performed for the β-amylase, blz-1, dmc1, nuc, and xly genes MITEs. These elements and their potential footprints were distributed in introns and intergenic spacers of many other nuclear genes throughout the BEP lineages; however, they were absent in the studied PACCMAD lineages. A plausible underlying dynamic of successive acquisitions and deletions of β-amylase Stowaway MITEs in the temperate grasses could be explained by three alternative hypotheses: (i) a single early acquisition of a palindrome element, similar to Tc1-Mariner, in the fourth intron of the β-amylase gene in the ancestor of the Pooideae, followed by multiple independent losses, (ii) multiple independent acquisitions of MITEs in non-related pooid lineages or (iii) different waves of acquisition of MITEs, followed by multiple losses and horizontal transfers in the temperate grasses. This last hypothesis seems to fit best with the evidence found to date.

  15. An updated conspectus of grasses of Punjab (India

    Directory of Open Access Journals (Sweden)

    Amarjit Singh Soodan

    2013-01-01

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

  16. Trabalho corporal na educação infantil: afinal, quem deve realizá-lo? Body work in early childhood education: finally who should actually achieve it?

    Directory of Open Access Journals (Sweden)

    Frederico Jorge Saad Guirra

    2010-09-01

    Full Text Available A educação infantil constitui-se no momento em que as crianças internalizam importantes conhecimentos que as auxiliarão para o resto de suas vidas, influenciando na sua formação e em suas práticas. O presente artigo reflete sobre o professor generalista, responsável pelo trabalho corporal, na educação infantil, de quais conhecimentos dispõe para desenvolver tal tarefa e como vê a importância desse trabalho para as crianças; aborda, ainda, segundo pesquisa realizada, a possível necessidade de um professor especialista na área para trabalhar o movimento e faz um questionamento sobre a preparação desse profissional para lidar com crianças de educação infantil. Conclui o presente, dialogando com essas questões e abrindo uma discussão sobre a possibilidade de um trabalho desses dois profissionais, em parceria, no sentido de garantir à criança, uma educação mais específica e que auxilie no seu desenvolvimento integral,Early childhood education is at the moment that the children internalize important knowledge that help the rest of their lives, influencing its formation and its practices. This article reflects on the teacher generalist, responsible for working on body movement with the children in early childhood education, which has expertise to develop such a task and sees the importance of this work for children, also discusses the second survey conducted, the possible need for a specialist teacher to work in the movement and is a question on the preparation of this work to deal with children in early childhood education. This article concludes the dialogue with these issues and open a discussion about the possibility of these two professionals work in partnership to ensure the child a more specific education and to help in its full development.

  17. Etalonnage et validation des échantillonneurs du type POCIS afin de quantifier les pesticides dans les cours d'eau

    OpenAIRE

    Fauvelle, V.

    2009-01-01

    The institutions responsible for the water quality monitoring, especially for pesticides, are currently employing a perfectible monitoring strategy: from 4 to 12 samples are analysed each year. By this way, not every peak of concentration is detected, and the LOQ is restricted by the instrumentation. Passive sampler like POCIS may be a good alternative, having a less analysis cost, more representative estimates, and a hard reduction of LOQ. However, the deployment of these kinds of devices in...

  18. Comportamiento electroquímico de colorantes antraquinónicos, azul de metileno, y compuestos afines en solución de solventes no-acuosos

    OpenAIRE

    Martínez Suárez, Jaime Fernando

    2017-01-01

    El trabajo realizado en esta Tesis doctoral pretende contribuir a la electroquímica orgánica, particularmente, en el campo del comportamiento electroquímico de colorantes en solución de solventes no acuosos. Se estudia por voltamperometría cíclica (VC) el comportamiento de los colorantes azul de metileno, alizarina, purpurina, ácido carmínico, quinalizarina y rojo de alizarina S, y además un precursor para la síntesis de colorantes indigoides, la isatina. El comportamiento electroquímico de l...

  19. A~fine fraction of soil used as an aerosol analogue during the DUNE experiment: sequential solubility in water with step-by-step decreasing pH

    Directory of Open Access Journals (Sweden)

    C. Aghnatios

    2014-02-01

    provides information on the necessary strength for the solubilisation of a given element and its lability. The behaviour of the elemental fractional solubility is sorted into two groups: (i Ca, Sr, Ba, Mn, P constitute group 1, with a solubility between 23% and 70% and with a maximum solubility at pH 3; (ii whereas in group 2 (Al, Fe, the solubility is less than 2% with the highest release at pH 1. Similar solubility patterns in group 1 for Ca, P and Mn suggest a~possible association of the elements in the same minerals, most probably carbonates, which gives phosphorus an unexpected high lability.

  20. Poder económico y prestigio social afines del siglo XVII. Una indagación sobre las dotes de las nobles castellanas

    Directory of Open Access Journals (Sweden)

    María Luz González Mezquita

    2013-11-01

    Full Text Available Este trabajo propone el estudio de las dotes desde una perspectiva diferente a las realizadas desde una óptica exclusivamente económica, teniendo en cuenta que la historia entendida como proceso implica nociones de mediación, causación, contradicción y organización sistemática, en ocasiones estructurante de la vida social, política, económica e intelectual. El estudio de fuentes primarias permite una aproximación tanto a las relaciones intranobiliarias centradas en estrategias familiares para la consolidación de linajes como a la política del monarca en relación con la nobleza que intenta explicar desde la historia política y social la simbiosis entre la Corona y los titulados. A pesar de la "crisis" de los patrimonios nobiliarios desde fines del siglo XVI, las dotes eran imprescindibles ante la realización de un matrimonio y esto producía muchas veces un desfasaje entre los ingresos y los gastos. El endeudamiento se cubría en estas oportunidades con préstamos o favores regios. En cualquier caso, factores ideológicos, de ordenamiento social, de poder, las hacían necesarias como mecanismo a través de los cuales se llevaba a la práctica la reproducción del sistema socialThis work proposes the study of dowries from a different perspective to those carried out from an exclusively economic optic, keeping in mind that history understood as a process implies mediation and contradiction notions and systematic organization, in occasions structuring the social, politic, economic and intellectual life. The study of primary sources allows an approximation at the same time to the relationships inside the nobility centered in family strategies for the consolidation of Iineages, and to the king's politics in connection with the nobility that tries to explain from political and social history, the symbiosis among the Crown and the nobility. In spite of the "crisis" of the nobiliary patrimonies from the late XVIth century, the dowries were indispensable before the realization of a marriage and this caused many times a negative relationship between the incomes and the expenses. The indebtedness was covered in these opportunities with loan or regal favors. Anyway, ideological factors, or social regulation and power factors, made dowries necessary as mechanisms through which took place the practice of reproducting the social system.

  1. Revisão de Elbella Evans e gêneros afins (Lepidoptera, Hesperiidae, Pyrrhopyginae Revision of Elbella Evans and related genera (Lepidoptera, Hesperiidae, Pyrrhopyginae

    Directory of Open Access Journals (Sweden)

    Olaf H. H Mielke

    1994-01-01

    Full Text Available A systematic study of the genera Microceris Watson, 1893, Elbella Evans, 1951, Parelbella. gen.n. (type species: Hesperia polyzona [Latreille, 1824], Pseudocroniades. gen.n. (type species: Ericides (sic machaon Westwood, [1852] and Protelbella, gen.n. (type species: Pyrrhopyga (sic alburna Mabille, 1891, a natural group of the Pyrrhopyginae, here called "Elbella Complex", is presented. The following are spp.n. and sspp.n.: Elbella intersecta paraensis, Brazil: Pará; Elbella intersecta rufitegula, Brazil: Pernambuco, Bahia, Minas Gerais, Espírito Santo and Rio de Janeiro State; Elbella viriditas boliviana, Bolivia: La Paz; Elbella lampra albociliata, Brazil: São Paulo, Paraná and Santa Catarina: Elbella azeta giffordi, Brazil: Distrito Federal and São Paulo; Elbella patrobas mexicana, Mexico: Chiapas and Quintana Roo; Elbella patrobas evansi, Colombia: Cauca, Caldas and Boyaca; Elbella patrobas tingo, Brazil: Rondonia and Peru: Huanuco and Madre de Dios; Elbella patrobas amazonica, Brazil: Amazonas; Parelbella peruana, Peru: Junin; Pseudocroniades machaon seabrai, Brazil: Rio de Janeiro State; Protelbella alburna brasiliensis, Brazil: Amazonas, Rondonia and Mato Grosso, and French Guiana: Montagne aux Cheveaux. The following genus is a syn.n.: Hegesippe Evans, 1951 of Elbella Evans, 1951. The following species and subspecies are syn.n.: Pyrrhopyga (sic semidentata Mabille, 1877 and Elbella intersecta ilona Evans, 1951 of Elbella intersecta intersecta (Herrich-Schäffer, 1869: Pyrrhopyge carriae Bell, 1931 of Elbella viriditas viriditas (Skinner, 1920; Pyrrhopyga (sic menecrates Mabille, 1878 and Pyrrhopyge margimmiscus Hayward, 1935 of Elbella lampra lampra (Hopffer, 1874; Elbella etna moda Evans, 1951 of Elbella etna Evans, 1951; Jemadia umbrata Mabille & Boullet, 1908 of Elbella patroclus patroclus (Plötz, 1879; Pyrrhopyga (sic jamina Butler, 1870 and Pyrrhopyga (sic zimra Hewitson, 1871 of Parelbella ahira ahira (Hewitson, 1857; Elbella zesta Evans, 1951 of Croniades pieria (Hewitson, 1857. The following are comb.n.: Elbella viriditas viriditas (Skinner, 1920; Elbella viriditas chia Evans, 1951; Elbella mariae molinai (Hayward, 1940: Elbella patroclus acala Evans, 1951; Parelbella polyzona (Latreille, [1824]; Parelbella ahira ahira (Hewitson, 1866; Parelbella ahira extrema (Röber, 1925; Parelbella macleannani (Godman & Salvin, 1893; Pseudocroniades machaon machaon (Westwood, [1852]: Protelbella alburna alburna (Mabille. 1891. The following are stat.n.: Elbella mariae molinai (Hayward, 1940; Elbella lustra Evans, 1951; Elbella blanda Evans, 1951. The following is a sp.rev.: Elbella patroclus patroclus (Plötz, 1879. The following is a nom.rev.: Elbella mariae molinai (Hayward, 1940. The following are stat.rev.: Elbella miodesmiata (Röber, 1925; Parelbella ahira ahira (Hewitson, 1866; Parelbella macleannani (Godman & Salvin, 1893. Lectotypes are designated for the following species or variety: Myscelus intersecta Herrich-Schäffer, 1869; Pyrrhopyga (sic fluminis Butler, 1873; Pyrrhopyga (sic semidentata Mabille, 1877; Pyrrhopyge lamprus Hopffer, 1874; Pyrrhopyga (sic menecrates Mabille, 1878; Pyrrhopyga (sic dulcinea Plöz, 1879; Pyrrhopyga (sic luteizona Mabille, 1877; Hesperia iphinous Latreille, [1824]; Pyrrhopyga (sic azeta Hewitson, 1866; Pyrrhopyga (sic patrobas Hewitson, 1857; Jemadia azeta var. melanina Mabille & Boullet, 1908; Pyrrhopyga (sic ahira Hewitson, 1866; Pyrrhopyga (sic jamina Butler, 1870; Pyrrhopyga (sic zimra Hewitson, 1871; Jemadia macleannani Godman & Salvin, 1893; Ericides (sic machaon Westwood,[1852] Pyrrhopyga (sic alburna Mabille, 1891. Neotypes are designated for the following species: Sarbia amoena Röber, 1925; Pyrrhopyga (sic othello Plötz, 1879; Mimoniades mimetes Mabille, 1909; Jemadia miodesmiata Röber, 1925; Jemadia umbrata Mabille & Boullet, 1908; Jemadia extrema Röber, 1925.

  2. Mas afinal, a memória é de quem? Histórias orais e modos de lembrar e contar

    Directory of Open Access Journals (Sweden)

    Antoinette Errante

    2012-06-01

    Full Text Available  Recentemente, a pesquisa em ciência social tem dado mais atenção às intrincadas relações entre biografia e história. Na pesquisa educacional, esse foco resultou numa explosão do interesse na narrativa pessoal como uma articulação da experiência individual e coletiva com os mundos social, político e cultural da educação. Esse interesse na narrativa pessoal deu, por conseqüência, proeminência ao trabalho em história oral. O crescimento da atração intuitiva das narrativas pessoais, no entanto, ganhou uma complacência metodológica. O que significa coletar e analisar narrativas pessoais? Como os narradores verbalizam suas narrativas e narram sua voz? Que papel exerce o jogo das entrevistas no desdobramento dessas narrativas? O que significam essas questões no contexto das histórias orais, que são narrativas em que a dinâmica entrevistador-narrador também é mediatizada pela natureza da memória? Este artigo examina o que a autora aprendeu sobre histórias orais das narrativas que a autora pôde, e não pôde,coletar.Palavras-chave: história oral, educação colonial, educação em Moçambique.   Abstract Social science inquiry has increasingly focused on the intricate relations between biography and history. In educational inquiry, this focus has led to an explosion of interest in the personal narrative as an articulation of individual and collective experience with the social, political and cultural worlds of education. This interest in the personal narrative has in tum given prominence to work in oral history as a research strategy. The growing intuitive appeal of personal narratives, however, has led to certain methodological complacency. What does it mean to collect and analyze personal narratives? How do narrators voice their narratives and narrate their voice? What role do interviewers play in the unfolding of these narratives? What do these questions mean in the context of oral histories, which are narratives where the interviewer-narrator dynamic is also mediated by the nature of memory? This paper examines what the author learned about oral histories from the narratives the author could, and could not, collect. Keywords: oral history, colonial history, education of Mozambique. 

  3. La academización de la educación técnica afines del Antiguo Régimen

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    Agustín ESCOLANO BENITO

    2013-11-01

    Full Text Available Este trabajo examina la génesis de la educación técnica academizada a finales del Antiguo Régimen. La institucionalización de la formación de los profesionales de la navegación, la industria, el comercio y la agricultura emerge en la segunda mitad del siglo XVIII en estrecha relación con los programas de fomento económico, de difusión de la ciencia y de la técnica modernas y del impulso pedagógico de la Ilustración. Este proceso de academización de los nuevos saberes desencadena la escisión escuela-taller y la revisión de la enseñanza gremial, dando origen a un nuevo modelo de educación de la juventud, contrapuesto al paradigma filológico dominante desde el Renacimiento en las escuelas secundarias y caracterizado por una ordenación curricular conformada a los presupuestos de la ciencia empírica, la matemática y los conocimientos útiles, por el discurso de la practicidad del saber y por el nuevo ethos de la burguesía.

  4. Aportes al análisis de la propuesta curricular de la Escuela Universitaria de Bibliotecología y Ciencias Afines

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    Isabel Madrid

    2013-12-01

    Full Text Available Este artículo se propone facilitar el debate sobre la problemática de desarrollo curricular de la EUBCA, la evaluación de los Planes de Estudios de las carreras de Archivología y Bibliotecología y las estrategias para decidir sobre eventuales cambios. Previo a innovar en los planes, se considera imprescindible salir de la rutina y dar una discusión teórico-metodológica, en un proceso de reflexión colectiva sobre un tema complejo. Teniendo en cuenta variables de contexto, los orígenes y el desarrollo histórico de las dos carreras, las características y el estado de los campos disciplinares y profesionales, así como aspectos académicos, sociales y humanos, se estará en mejores condiciones de proponer nuevas estrategias curriculares.

  5. Revisão de Elbella Evans e gêneros afins (Lepidoptera, Hesperiidae, Pyrrhopyginae) Revision of Elbella Evans and related genera (Lepidoptera, Hesperiidae, Pyrrhopyginae)

    OpenAIRE

    Mielke,Olaf H.H.

    1994-01-01

    A systematic study of the genera Microceris Watson, 1893, Elbella Evans, 1951, Parelbella. gen.n. (type species: Hesperia polyzona [Latreille, 1824]), Pseudocroniades. gen.n. (type species: Ericides (sic) machaon Westwood, [1852]) and Protelbella, gen.n. (type species: Pyrrhopyga (sic) alburna Mabille, 1891), a natural group of the Pyrrhopyginae, here called "Elbella Complex", is presented. The following are spp.n. and sspp.n.: Elbella intersecta paraensis, Brazil: Pará; Elbella intersecta ru...

  6. Afinal, o que é pseudonotícia?: um estudo sobre o The i-Piauí Herald, O Sensacionalista e o Laranjas News

    OpenAIRE

    Gerson, Deborah Cattani

    2014-01-01

    Esta pesquisa ocupa-se da investigação sobre o que é a pseudonotícia e como ocorrem determinadas paródias de jornalismo no Brasil. Para tal, foram analisados os sites do The i-Piuaí Herald, Sensacionalista e Laranjas News. Através de uma revisão teórica, que se cunha no humor, no entretenimento e na filosofia de linguagem, esta dissertação se propõe a buscar uma determinação para o funcionamento deste novo, nem tão novo, nicho de comunicação. Bibliográfica, a investigação se apoia em multidis...

  7. Estudo genético-clínico e molecular da síndrome de Rokitansky-Mayer-Küster-Hauser e condições afins

    OpenAIRE

    2008-01-01

    Introdução: A síndrome ou seqüência malformativa de Rokitansky-Mayer-Küster-Hauser (SR), de caráter geralmente esporádico, caracteriza-se por aplasia útero-vaginal, freqüentemente associada a anomalias esqueléticas e do trato urinário e a caracteres sexuais secundários, hormônios esteróides e cariótipo normais. A condição é claramente heterogênea, podendo fazer parte de outras seqüências e complexos mais abrangentes. Sua freqüência ao nascimento foi estimada em cerca de 1/5.000 meninas. O ban...

  8. Aportes al análisis de la propuesta curricular de la Escuela Universitaria de Bibliotecología y Ciencias Afines

    OpenAIRE

    Isabel Madrid; María Cristina Pérez

    2013-01-01

    Este artículo se propone facilitar el debate sobre la problemática de desarrollo curricular de la EUBCA, la evaluación de los Planes de Estudios de las carreras de Archivología y Bibliotecología y las estrategias para decidir sobre eventuales cambios. Previo a innovar en los planes, se considera imprescindible salir de la rutina y dar una discusión teórico-metodológica, en un proceso de reflexión colectiva sobre un tema complejo. Teniendo en cuenta variables de contexto, los orígenes y el des...

  9. Prólogo al Diccionario de Bibliología y Ciencias afines de José Martinez de Sousa

    OpenAIRE

    Cordón-García, José-Antonio

    2004-01-01

    [ES] Por Bibliología no se ha entendido siempre lo mismo existiendo notables diferencias entre la concepción omnicomprensiva de Otlet, o las mas recientes de Estivals, Jacques Breton o Serrai. Pero independientemente de que se aplique un criterio mas restrictivo o mas amplio al objeto de la misma, que ha pasado de ser el documento en general (Otlet), el libro (Serrai), el escrito (Estivals), el escrito impreso (Breton), todos coinciden en que su finalidad es el estudio de los procesos implica...

  10. Nível de alfabetização financeira dos estudantes universitários: afinal, o que é relevante? [doi: 10.5329/RECADM.2013025

    Directory of Open Access Journals (Sweden)

    Ani Caroline Grigion Potrich

    2013-12-01

    Full Text Available O presente estudo teve por objetivo verificar se os estudantes universitários são alfabetizados financeiramente e se a alfabetização é afetada por variáveis socioeconômicas e demográficas. Foram aplicados questionários a 534 estudantes de graduação de universidades na região central do Rio Grande do Sul. Os resultados revelam que os estudantes apresentam um comportamento financeiro positivo, mas não satisfatório, dado que não têm, de forma bem estabelecida, hábitos de poupar mensalmente e de manter uma reserva financeira para casos inesperados. Além disso, possuem atitudes financeiras adequadas, apesar de demonstrarem um nível insatisfatório de conhecimento financeiro, culminando em um grau mediano de alfabetização financeira. Os indivíduos do gênero masculino, detentores das maiores faixas de renda e com formação financeira são os que apresentaram os níveis mais elevados de alfabetização financeira. Constatou-se, ainda, que a alfabetização financeira é influenciada positivamente pelas variáveis formação, ocupação, gênero e renda. Assim, ratifica-se a urgência e a necessidade de serem desenvolvidas ações efetivas para minimizar o problema do analfabetismo financeiro.   Palavras-chave Alfabetização financeira; conhecimento financeiro; comportamento financeiro; atitude financeira; estudantes universitários.     LEVEL OF FINANCIAL LITERACY OF COLLEGE STUDENTS: WHAT IS RELEVANT? ABSTRACT The present study aimed to verify whether college students are financially literate and whether literacy is affected by socioeconomic and demographic variables. Questionnaires were applied to 534 undergraduate students from universities in the central region of Rio Grande do Sul. The results have indicated that students have a positive financial behavior, but not satisfactory. It has also been found that they do not have well-established habits to save monthly and to maintain a financial reserve for unexpected cases. Although they have adequate financial attitudes, they have showed an unsatisfactory level of financial knowledge, culminating in a moderate degree of financial literacy. The male individuals with higher income brackets and financial training are those with the highest levels of financial literacy. It was also found that financial literacy is positively influenced by variables such us training, occupation, gender and income. This way, the urgent need to develop effective actions to minimize the problem of financial illiteracy has been confirmed. Keywords Financial literacy; financial knowledge; financial behavior; financial attitude; college students.

  11. Intoxicação por Sorhgum halepense (Poaceae em bovinos no semi-árido Poisoning by Sorghum halepense (Poaceae in cattle in the Brazilian semiarid

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    J. Escarião da Nóbrega Jr

    2006-12-01

    Full Text Available Descreve-se um surto de intoxicação por Sorghum halepense (L. Pers. no município de Santa Luzia, semi-árido da Paraíba. Nove bovinos foram colocados numa pastagem com S. halepense em fase de rebrota, com 25-30cm de altura, 15 dias após as primeiras chuvas. Sinais clínicos de dispnéia, ansiedade, tremores musculares e incoordenação apareceram 10-15 minutos após a ingestão. Dois animais morreram em um período aproximado de 3 horas. Na necropsia observaram-se congestão e cianose das mucosas, musculatura escura, pulmão com pontos hemorrágicos e edema, além de folhas da planta no rúmen. A planta foi positiva no teste do papel picrosódico. Mudas de S. halepense coletadas no Município de Currais Novos, Rio Grande do Norte, onde havia históricos de uma intoxicação semelhante, foram plantadas em vasos e realizado o teste de papel picrosódico a cada 15 dias. A planta foi positiva para HCN durante todos os estágios, sendo que nos primeiros 45 dias a reação ocorreu dentro de 1 minuto e, posteriormente, em até 3 minutos. Trinta dias após ter sido plantada, a planta de um dos vasos foi administrada a um caprino causando sinais característicos de intoxicação cianídrica na dose de 11,8g/kg de peso do animal. O caprino se recuperou após tratamento com uma solução de tiossulfato de sódio a 20% na dose de 5mL/10kg. No semi-árido, S. halepense é freqüentemente encontrado como invasora em beiras de açudes e culturas irrigadas, sendo utilizado como forrageira, na época seca, em áreas de vazante.An outbreak of poisoning by Sorghum halepense (L. Pers. in cattle in the Brazilian semiarid is reported. Nine cattle were introduced 15 days after the first rains into a paddock where the plant was sprouting and had 25-30cm high. Clinical signs of dyspnea, anxiety, muscular tremors and incoordination appeared 15 minutes after the animals began to graze. Two of them died within about 3 hours. The others recovered. Cyanotic mucosa, dark muscles, lung edema and hemorrhages, and leaves of the plant in the rumen were observed at necropsy. The plant was positive for the picrosodic paper test. S. halepense from another farm of occurrence of the poisoning was transplanted into two pots. The picrosodic paper test was performed fortnightly in the plants growing in one of them. The plant was positive for cyanide in all growth stages; during the first 45 days the test was positive within 1 minute, but after day 60 within 3 minutes. Thirty days after the plant had been transplanted into one of the pots, it was administered to a goat at a dose of 11.8g/kg, causing clinical signs of HCN poisoning. The animal recovered after the intravenous administration of 5mL/10kg body weight of a 20% sodium thiosulfate solution. In the Brazilian semiarid S. halepense is frequently found invading the border of ponds and irrigated crops, and is used as forage during the dry season.

  12. Microsporogenesis in Brachiaria bovonei (Chiov. Robyns and B. subulifolia (Mez Clayton (Poaceae Microsporogênese em Brachiaria bovonei (Chiov. Robyns e B. subulifolia (Mez Clayton (Poaceae

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    Claudicéia Risso-Pascotto

    2009-10-01

    Full Text Available Some African species of Brachiaria have been introduced into the Americas and became the most important forage for pastures in the tropics. New cultivars can be obtained either from direct selections from the natural existing variability in the germplasm collections or from interspecific hybridizations. Polyploidy is predominant in the genus Brachiaria and correlated with apomixis which complicates hybridization. The objective of cytological studies underway on the Brachiaria germplasm collection at Embrapa Beef Cattle is to determine the chromosome number and meiotic behavior of accessions. For the breeding of Brachiaria species, compatible sexual and apomictic accessions need to be identified. Microsporogenesis was evaluated in two accessions of Brachiaria bovonei (BO01 and BO05 and one accession of B. subulifolia (SU01. BO01 is pentaploid (2n = 5x = 45, BO05 is tetraploid (2n = 4x = 36, and SU01 is hexaploid (2n = 6x = 54, derived from x = 9. Meiotic abnormalities typical of polyploids, characterized by precocious chromosome migration to the poles in metaphases, laggard chromosomes in anaphases, and micronuclei in telophases and tetrads, were recorded in high frequency in all the accessions generating unbalanced gametes. Both accessions of B. bovonei presented chromosome stickiness. The results are discussed in the view of the Brachiaria breeding program objectives.Algumas espécies africanas de Brachiaria foram introduzidas nas Américas e tornaram-se importantes pastagens nos trópicos. Novas cultivares podem ser obtidas por seleção direta da variabilidade genética existente na coleção de germoplasma ou por hibridização interespecífica. Poliploidia é predominante no gênero Brachiaria e correlacionada com apomixia, o que complica a hibridização. O objetivo dos estudos citogenéticos na coleção de germoplasma de Brachiaria da Embrapa Gado de Corte é determinar o número de cromossomos e o comportamento meiótico dos acessos. A microsporogênese foi avaliada em dois acessos de Brachiaria bovonei (BO01 e BO05 e um acesso de B. subulifolia (SU01. BO01 é pentaplóide (2n = 5x = 45, BO05 é tetraplóide (2n = 4x = 36, e SU01 é hexaplóide (2n = 6x = 54, todos derivados de x = 9. Anormalidades meióticas típicas de poliplóides, caracterizadas por migração precoce de cromossomos para os pólos em metáfases, cromossomos retardatários em anáfases, e micronúcleos em telófases e tétrades foram observadas em alta freqüência em todos os acessos gerando gametas geneticamente desbalanceados. Ambos os acessos de B. bovonei apresentaram aderências cromossômicas. Os resultados são discutidos sob o ponto de vista dos objetivos do melhoramento genético.

  13. The role of seasonal flowering responses in adaptation of grasses to temperate climates

    Science.gov (United States)

    Fjellheim, Siri; Boden, Scott; Trevaskis, Ben

    2014-01-01

    Grasses of the subfamily Pooideae, including important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons so that flowering and seed production coincide with favorable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group. PMID:25221560

  14. The role of seasonal flowering responses in adaptation of grasses to temperate climates.

    Directory of Open Access Journals (Sweden)

    Siri eFjellheim

    2014-08-01

    Full Text Available Grasses of the subfamily Pooideae, which includes important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons, so that flowering and seed production coincide with favourable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group.

  15. Parteiras-enfermeiras e Enfermeiras-parteiras: a interface de profissões afins, porém distintas Parteras-enfermeras y enfermeras-parteras: la interface entre dos profesiones afines, pero distintas Midwive-nurses and nurse-midwives: the interface of professionals sharing affinity, but differents

    Directory of Open Access Journals (Sweden)

    Ruth Hitomi Osawa

    2006-10-01

    Full Text Available Em 2005, com a criação do Curso de Graduação em Obstetrícia da Universidade de São Paulo, as discussões em torno dos modelos de formação de profissionais não-médicos para a assistência ao parto foram reaquecidas. O objetivo do estudo é aprofundar a compreensão do significado da retomada do referido Curso no momento atual da assistência ao parto e nascimento. Os eventos do passado que influenciaram nos modelos de assistência ao parto por não-médicos foram considerados: a aprovação da lei das parteiras na Inglaterra, em 1902, com a inclusão de sua prática ao sistema de saúde oficial, a marginalização do trabalho da parteira tradicional nos Estados Unidos da América e os momentos emblemáticos das disputas de enfermeiras e obstetrizes (parteiras no Brasil.En el 2005, con la creación del Curso Universitario de Obstetricia de la Universidad de São Paulo, las discusiones sobre los modelos de formación de profesionales no-médicos para la atención al parto se intensificaron. El objetivo de este estudio es profundizar la comprensión del significado de la retomada del Curso de Obstetricia en el momento actual de la atención al nacimiento. Se presentan: los eventos del pasado que tuvieron gran influencia en los modelos corrientes de atención al parto por no-médicos; la aprobación de la ley de las parteras en Inglaterra, en el 1902, que incluyó su práctica al sistema de salud oficial; la marginalización del trabajo de la partera tradicional en los Estados Unidos de América y los momentos emblemáticos de las disputas entre enfermeras y matronas (parteras en Brasil.In 2005, the Midwifery course at undergraduate level was created at the University of Sao Paulo, which has intensified discussions about educational models for non-medical professionals for delivery care. This study aims at deepen the understanding of meanings related to re-starting the mentioned course at the present moment involving delivery and childbirth care. Past events that have influenced models for delivery care by non-medical personnel were considered: the enactment of a law for midwives in England, in 1902, which included this practice into the official national health system, the traditional midwife work in the USA considered as peripheral and emblematic moments dispute between nurses and midwives in Brazil.

  16. Reticulate evolution in Panicum (Poaceae): the origin of tetraploid broomcorn millet, P. miliaceum.

    Science.gov (United States)

    Hunt, Harriet V; Badakshi, Farah; Romanova, Olga; Howe, Christopher J; Jones, Martin K; Heslop-Harrison, J S Pat

    2014-07-01

    Panicum miliaceum (broomcorn millet) is a tetraploid cereal, which was among the first domesticated crops, but is now a minor crop despite its high water use efficiency. The ancestors of this species have not been determined; we aimed to identify likely candidates within the genus, where phylogenies are poorly resolved. Nuclear and chloroplast DNA sequences from P. miliaceum and a range of diploid and tetraploid relatives were used to develop phylogenies of the diploid and tetraploid species. Chromosomal in situ hybridization with genomic DNA as a probe was used to characterize the genomes in the tetraploid P. miliaceum and a tetraploid accession of P. repens. In situ hybridization showed that half the chromosomes of P. miliaceum hybridized more strongly with labelled genomic DNA from P. capillare, and half with labelled DNA from P. repens. Genomic DNA probes differentiated two sets of 18 chromosomes in the tetraploid P. repens. Our phylogenetic data support the allotetraploid origin of P. miliaceum, with the maternal ancestor being P. capillare (or a close relative) and the other genome being shared with P. repens. Our P. repens accession was also an allotetraploid with two dissimilar but closely related genomes, the maternal genome being similar to P. sumatrense. Further collection of Panicum species, particularly from the Old World, is required. It is important to identify why the water-efficient P. miliaceum is now of minimal importance in agriculture, and it may be valuable to exploit the diversity in this species and its ancestors.

  17. Schoenefeldia transiens (Poaceae: Rare new record from the Limpopo Province, South Africa

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    Aluoneswi C. Mashau

    2014-07-01

    Full Text Available Background: Schoenefeldia is a genus of C4 grasses, consisting of two species in Africa, Madagascar and India. It is the only representative of the genus found in southern Africa, where it was previously only known from a few collections in the southern part of the Kruger National Park (Mpumalanga Province, South Africa, dating from the early 1980s.Objectives: The objective of this study was to document a newly recorded population of Schoenefeldia transiens in an area that is exploited for coal mining.Method: A specimen of S. transiens was collected between Musina and Pontdrift, about 30 km east of Mapungubwe National Park, in the Limpopo Province of South Africa. The specimen was identified at the National Herbarium (Pretoria.Results: This is not only a new distribution record for the quarter degree grid (QDS: 2229BA, but is also the first record of this grass in the Limpopo Province. The population of S. transiens has already been fragmented and partially destroyed because of mining activities and is under serious threat of total destruction.Conclusion: It is proposed that the population of S. transiens must be considered to be of conservation significance, and the population should be made a high priority in the overall environmental management programme of the mining company that owns the land.

  18. Ultrastructure and histology of organogenesis induced from shoot tips of maize (Zea mays, Poaceae

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    Walter Marín-Méndez

    2009-11-01

    Full Text Available Shoot tips of maize (Zea mays L. were cultured on Murashige and Skoog medium supplemented with 2 mg/l BA +1 mg/l 2,4-D +40 mg/l, to investigate phases of ontogenetic development. The study used light microscopy as well as scanning and transmission electronic microscopy techniques. Shoot tips of maize are composed of small cells with a dense cytoplasm and a prominent nucleus. The process of organogenesis began with swelling of the shoot tip, as the first evidence of organogenic calli formation observed three weeks after culture get started. There were two morphologically different types of cells within the organogenic calli. The layer consisted of large cells with small nucleus, free-organelle cytosol, irregular plasmatic membrane, trichome-like structures, and thick cell walls. In the inner cell layer, small and isodiametric cells with a prominent nucleus, small vacuoles, endoplasmatic reticulum, Golgi, mitochondrias and chloroplasts were observed. The presence of trichomes in the more active morphogenic zones could indicate an organogenic potential. Rev. Biol. Trop. 57 (Suppl. 1: 129-139. Epub 2009 November 30.Los ápices de vástagos de maíz (Zea mays L. fueron cultivados con el medio Murashige y Skoog, utilizando como suplemento 2 mg/l BA +1 mg/l 2,4-D +40 mg/l, con el fin de investigar el proceso organogénico durante las diferentes fases del desarrollo ontogenético. El estudio utilizó tanto microscopía de luz, como técnicas de microscopía electrónica. Los análisis histológicos revelaron que los vástagos de maíz están compuestos de pequeñas células con citoplasma denso y núcleo prominente. El proceso de organogénesis inicia con el engrosamiento del ápice del vástago, como primera evidencia de la formación organogénica del calli observada tres semanas después del inicio del cultivo. El estudio ultraestructural muestra dos tipos de células morfológicamente diferentes en el calli organogénico. La capa externa consiste de células grandes con núcleo pequeño, citosol sin organelas, membrana plamática irregular, estructuras similares a tricomas y paredes celulares delgadas. Mientras que en la capa interna se observaron células pequeñas e isodiamétricas con un núcleo prominente, vacuolas pequeñas, retículo endoplasmático, Golgi, mitocondrias y cloroplastos. Observaciones de microscopía electrónica revelan la organización externa de la organogénesis del calli del maíz. Los resultados obtenidos en el presente estudio contribuyen con la comprensión del proceso de organogénesis en los ápices de los vástagos del maíz. Este estudio mejorará nuestro conocimiento acerca de los estados anatómicos óptimos para la integración estable de genes externos. Además, provee información de las condiciones apropiadas en el cultivo in vitro para la regeneración de plantas transgénicas. Este estudio sugiere que la presencia de tricomas en las zonas morfogénicas más activas podría indicar su potencial organogénico.

  19. Panicum simulans (Paniceae, Poaceae), a new species from southern Africa and its leaf anatomy

    OpenAIRE

    L. Smook; Ellis, R. P.

    1993-01-01

    Panicum simulans Smook from northern Namibia is formally described. The morphology and leaf blade anatomy in transection and surface view, as observed under the light microscope, are described. The species is compared to others with which it has been confused in the past.  P. simulans can be readily distinguished from  P. novemnerve Stapf and P schinzii Hack, on the basis of both anatomical and morphological characters such as the venation of the lower glume and the photosynthetic anatomy, wh...

  20. Panicum simulans (Paniceae, Poaceae, a new species from southern Africa and its leaf anatomy

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    L. Smook

    1993-12-01

    Full Text Available Panicum simulans Smook from northern Namibia is formally described. The morphology and leaf blade anatomy in transection and surface view, as observed under the light microscope, are described. The species is compared to others with which it has been confused in the past.  P. simulans can be readily distinguished from  P. novemnerve Stapf and P schinzii Hack, on the basis of both anatomical and morphological characters such as the venation of the lower glume and the photosynthetic anatomy, which is of the NAD-me subtype of the C4 photosynthetic pathway. On this basis it appears that P simulans is closely allied to the P. coloratum L. group of species and should be placed in section Panicum of subgenus Panicum.

  1. Chromosome number, microsporogenesis, microgametogenesis, and pollen viability in the Brazilian native grass Mesosetum chaseae (Poaceae).

    Science.gov (United States)

    Silva, L A C; Pagliarini, M S; Santos, S A; Silva, N; Souza, V F

    2012-11-28

    The genus Mesosetum is a primarily South American genus with 42 species. Mesosetum chaseae, regionally known as 'grama-do-cerrado', is abundant in the Pantanal Matogrossense (Brazil); it is a valuable resource for livestock and for environmental conservation. We collected specimens from the Nhecolandia sub-region of the Brazilian Pantanal, located in Corumbá, Mato Grosso do Sul, Brazil. We examined chromosome number, ploidy level, meiotic behavior, microgametogenesis, and pollen viability of 10 accessions. All the accessions were diploid, derived from x = 8, presenting 2n = 2x = 16 chromosomes. Chromosomes paired as bivalents showing, predominantly, two terminal chiasmata. Interstitial chiasmata were rare. Meiosis was quite normal producing only a few abnormal tetrads in some accessions. Microgametogenesis, after two mitotic divisions, produced three-celled pollen grains. Pollen viability was variable among plant and accessions and was not correlated with meiotic abnormalities.

  2. Leaf anatomy of the genus Ehrharta (Poaceae in southern Africa: the Villosa group

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    R. P. Ellis

    1987-12-01

    Full Text Available The leaf blade anatomy of Ehrharta villosa Schult. f. var.  villosa, var.  maxima Stapf and  E. thunbergii Gibbs Russell is described and illustrated. These three taxa, constituting the Villosa species group, share a diagnostic leaf anatomy distinguished by the absence of a distinct midrib, adaxial semi-radiate mesophyll with the abaxial chloren- chyma palisade-like in arrangement, rectangular long cells and the stomatal apertures which are overlapped by four cuticular flanges projecting from the two adjacent interstomatal cells. These combined attributes characterize this species group, and the stomatal flanges are unique to this group in the genus Ehrharta Thunb. Microhairs are absent in  E. villosa but are present in  E. thunbergii which also possesses abaxial prickles and plentiful, rounded silica bodies not associated with cork cells as in  E. villosa. These two taxa can. therefore, be separated anatomically. Nevertheless, they share many features and are undoubtedly closely related and their classification in the same species group is substantiated by the anatomical evidence presented in this paper.

  3. Desynapsis and precocious cytokinesis in Brachiaria humidicola (Poaceae) compromise meiotic division

    Indian Academy of Sciences (India)

    Vergílio Calisto; Veridiana Aparecida Fuzinatto; Hugo José Message; Andréa Beatriz Mendes-Bonato; Kellen Regina Boldrini; Maria Suely Pagliarini; Cacilda Borges Do Valle

    2008-04-01

    The forage grass species Brachiaria humidicola is native to African savannas. Owing to its good adaptation to poorly drained and infertile acid soils, it has achieved wide utilization for pastures in Brazilian farms. Among the 55 accessions of B. humidicola analysed from the Embrapa Beef Cattle collection, one (H022), presented desynapsis and an abnormal pattern of cytokinesis in the first meiotic division. Among 28 inflorescences analysed in this accession, 12 were affected by the anomaly. In affected meiocytes, the first cytokinesis occurred in metaphase I and was generally perpendicular to a wide-metaphase plate, dividing the genome into two parts with an equal or unequal number of chromosomes. The normal cytokinesis after telophase I did not occur, and the meiocytes entered metaphase II, progressing to the end of meiosis with the occurrence of the second cytokinesis. As the first cytokinesis occurred precociously, whereas the second was normal, tetrads were formed but with unbalanced chromosome numbers in microspores. Abnormal cytokinesis occurred only in those meiocytes that underwent desynapsis after diakinesis. The implications of this abnormality in the Brachiaria breeding programme are discussed.

  4. Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae)

    Indian Academy of Sciences (India)

    Gléia Cristina Laverde Ricci; Alice Maria De Souza-Kaneshima; Mariana Ferrari Felismino; Andrea Beatriz Mendes-Bonato; Maria Suely Pagliarini; Cacilda Borges Do Valle

    2011-08-01

    A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented $2n = 18$; 27 accessions, $2n = 36$; and 2 accessions, $2n = 45$ chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.

  5. An easy and rapid method using microscopy to determine herbicide effects in Poaceae weed species.

    Science.gov (United States)

    Hjorth, Maibritt; Mondolot, Laurence; Buatois, Bruno; Andary, Claude; Rapior, Sylvie; Kudsk, Per; Mathiassen, Solvejg K; Ravn, Helle W

    2006-06-01

    A new, easy, rapid and relatively inexpensive method using microscopy has been developed for the detection of herbicide effects in leaves of grass weed species displaying no visual signs of damage. The method has potential to be used as a tool to indicate future death of grass species due to herbicide exposure by observing phytochemical effects, i.e. early-warning effects. In the present study, Apera spica-venti (L.) Beauv., Bromus hordeaceus L., Alopecurus myosuroides Huds., Lolium perenne L. and Poa annua L. were exposed to lethal rates of four herbicides with different mode of action. The herbicides investigated were the thiocarbamate: prosulfocarb, the sulfonylurea: iodosulfuron, the aryloxyphenoxypropionate: fenoxaprop-P-ethyl and the organophosphate glyphosate. Autofluorescence of leaves was studied under a microscope using ultraviolet and blue light. The fluorescence of leaves treated to enhance flavonoids was also examined. To confirm the results, microspectrofluorometry was performed. Effects indicating future death of the grasses were observed in visually healthy leaves following treatment with prosulfocarb, glyphosate and iodosulfuron. No changes were detected following treatment with fenoxaprop-P-ethyl. After exposure to glyphosate or iodosulfuron, changes in the content of flavonoids and other compounds with a conjugation system and rigid structure and a decrease in the content of chlorophyll were detected in the leaves. Prosulfocarb treatment resulted in changes in the content of flavonoids and other compounds with a conjugation system and rigid structure and an increase in the content of chlorophyll in the leaves. The results obtained from microspectrofluorometry indicated that exposure to prosulfocarb caused a reduction in the flavonoids quercetin, naringenin and/or naringin. Copyright (c) 2006 Society of Chemical Industry

  6. Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae) in the Brazilian Amazon

    OpenAIRE

    Fernandes Júnior,Paulo Ivan; Duarte Pereira, Gilmara Maria; Perin, Liamara; da Silva, Luana Mesquita; Cardoso Baraúna, Alexandre; Muniz Alves, Francilene; Ribeiro Passos, Samuel; Édson Zilli, Jerri

    2013-01-01

    The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepat...

  7. Review of the Genus Andropogon (Poaceae: Andropogoneae in America Based on Cytogenetic Studies

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    Nicolás Nagahama

    2012-01-01

    Full Text Available Andropogon is a pantropical grass genus comprising 100–120 species and found mainly in the grasslands of Africa and the Americas. In the new world the genus is represented by approximately sixty (diploids or hexaploids species grouped in three sections. The hexaploid condition occurs only in the Americas and the full process of this origin is still uncertain, although cytogenetic analysis coupled with taxonomic evidence have provided strong support for new hypothesis. Stebbins proposed the first hypothesis suggesting that the origin of polyploidy in species of Andropogon in North America resulted from duplication of the genome of some diploid species, and then by intergeneric crosses with species of a related genus. Since then, numerous studies were performed to clarify the evolutionary history of the genus in America. In this paper, we present a review of cytogenetic studies in the American Andropogon species during the last four decades.

  8. Ptilagrostis contracta (Stipeae, Poaceae), a New Species Endemic to Qinghai-Tibet Plateau

    Science.gov (United States)

    Zhang, Zhong-Shuai; Li, Ling-Lu

    2017-01-01

    A new species, Ptilagrostis contracta, endemic to Qinghai-Tibet Plateau is described and illustrated. It is distinguished from other species in Ptilagrostis by having contracted panicles, 1-geniculate awns with hairy columns and scabrous bristles and evenly pubescent lemmas. Evidence from lemma epidermal pattern, cytology and molecular phylogenetic analyses based on the nuclear ITS sequence data confirm its systematic position in Ptilagrostis. PMID:28060805

  9. Estructura del disemínulo en especies de Andropogoneae (Poaceae

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    Vegetti, Abelardo C.

    1998-06-01

    Full Text Available The disseminule in Andropogoneae is studied, analizing its structure and characteristics in the different subtribes. The shape and function of the components of the dispersal units (rachis segment and spikelets, especially the glumes are discussed in relation to the protection of the floral organs and the dispersal of the fruit. Some evolutionary trends are suggested.Se estudia exomorfológica y anatómicamente el disemínulo en especies de Andropogoneae pertenecientes a distintas subtribus. Se relacionan las características del artejo del raquis y del par de espiguillas desarrolladas en su nudo proximal, con la protección dada a las flores y con la dispersión del fruto. Se proponen posibles tendencias filogenético.

  10. Sediment composition mediates the invasibility of aquatic ecosystems by a non-native Poaceae species

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    José Vitor Botter Fasoli

    2015-06-01

    Full Text Available Aim: To test the invasibility of aquatic ecosystems by an exotic species, we used the invasive macrophyte Urochloa arrecta, which has invaded many Neotropical waterbodies and has reduced biodiversity in these habitats. The extensive growth of this macrophyte can be related to its affinity for mud-rich sediments, which occur primarily in secondary river channels and lentic habitats.MethodsTo test this hypothesis, we cultivated U. arrecta in trays with different percentages of mud and we measured the sprout length and biomass of the plants after 75 days.ResultsOur results showed a positive and significant relationship between sediment mud percentage and nitrogen, phosphorus and organic matter. Both plant length and biomass increased significantly and continuously with increasing mud content, indicating that the growth of this species is not limited even at the highest levels of mud, which is shown to be toxic for other species of macrophytes. Thus, it is probable that sand-rich sites, such as river shores, are less vulnerable to invasion by this species than relatively mud-rich sites, such as lakes.ConclusionsThis finding indicates that relatively mud-rich ecosystems should be prioritised in monitoring programs to prevent invasion by this species. In addition, the slow development of this species in sandy sediments opens a potential window for its management, at least on small spatial scales. However, despite the reduced growth of U. arrecta in sand-rich sediments, this grass is able to grow in several types of sediments, which explains its spread in a variety of habitats in Neotropical freshwater ecosystems.

  11. Preliminary DNA fingerprinting of the turf grass Cynodon dactylon (Poaceae: Chloridoideae

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    R. Roodt

    2002-12-01

    Full Text Available Identification of different cultivars of turf grasses is often very difficult. In a preliminary attempt to identify different cultivars o f Cynodon dactylon (L. Pers.. random amplified polymorphic DNA (RAPD analyses of some well-known cultivars used in South Africa, i.e. Bayview. Cape Royal, Florida. Hamsmith. Silverton Blue. Skaapplaas and Titdwart. as well as 10 potential new cultivars, were done. These results were used to determine the genetic distances among cultivars. Only five primers w ere needed to obtain a specific fragment pattern for each cultivar. The degree o f amplification w as used as an additional criterion by including all visible fragments, excluding very faint fragments and only including the brightest fragments. The neighbour-joining trees o f C.  dactylon showed best resolution from the data set w ith all visible fragments included. although fragment intensity did not affect the tree topology. The cultivars Silverton Blue and Bayview exhibited the greatest genetic variation and two potential new cultivars were identified. RAPD analyses can. therefore, be used to distin­guish between different C. dactylon cultivars and to determine the genetic variation between them by calculating genetic distances.

  12. Multiple homoplasious insertions and deletions of a Triticeae (Poaceae DNA transposon: a phylogenetic perspective

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    Mason-Gamer Roberta J

    2007-06-01

    Full Text Available Abstract Background Stowaway elements are short, non-autonomous DNA transposons categorized as miniature inverted-repeat transposable elements (MITEs. The high MITE copy number in grass genomes suggests an active history of amplification and insertion, but ongoing MITE activity has only rarely been seen, and ongoing Stowaway activity has never been observed. Thus, a phylogenetic perspective on presence vs. absence of elements in an aligned data set can provide valuable historical insights into the dynamics of MITE acquisition and loss. Results A Stowaway-like element resides within the fourth intron of a β-amylase gene in representatives of five genera in the wheat tribe, Triticeae. Its presence vs. absence was examined with reference to the β-amylase gene tree topology, and in light of sequence comparisons of the β-amylase elements to Triticeae Stowaway elements in the Entrez nucleotide database. Among the sequences lacking the element, there are five distinct putative excision footprints (one widespread and four restricted to unrelated lineages and two flanking deletions. The sequences that do contain elements are polyphyletic on the β-amylase tree, and their elements are divergent at the sequence level. The β-amylase elements do not form a monophyletic group relative to other Stowaway elements in Entrez; most are more similar to elements from other loci in other Triticeae genomes than they are to one another. Conclusion Combined, the phylogenetic distribution, sequence variation, and Entrez database comparisons indicate that a Stowaway-like element has undergone multiple deletions from and insertions into the same site in β-amylase intron 4 during the history of the tribe. The elements currently at the site represent multiple, distinct lineages that transcend generic boundaries. While patterns of Stowaway polymorphism across a phylogenetic data set do not allow evolutionary mechanisms to be inferred with certainty, they do provide insights into the dynamics of element evolution over an extended time scale. The historical perspective provided by a phylogenetic approach is complementary to the few studies in which ongoing MITE activity has been documented.

  13. Muhlenbergia monandra (Poaceae: Eragrostideae, nueva especie anual endémica del Perú

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    J. José Alegría Olivera

    2001-01-01

    Full Text Available Se describe e ilustra Muhlenbergia monandra, endémica de Perú. La nueva especie se caracteriza por sus glumas mayores que el antecio, por tener inflorescencias espiciformes y las flores cleistógamas con un estambre. La anatomía foliar se describe e ilustra y se detallan sus caracteres diferenciales. Se incluyen observaciones sobre la epidermis de la lemma y las glumas realizadas con el Microscopio Electrónico de Barrido. Se discute la posición taxonómica de la nueva entidad y las diferencias con las especies anuales relacionadas que habitan en América del Sur

  14. Regional variation in Argentinean populations of Bromus catharticus (Poaceae as measured by morphological

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    Arturi, Miguel J.

    2008-06-01

    Full Text Available Thirty-one populations of Bromus catharticus Vahl., collected from the Pampean Dominion (Argentina, were classified using twenty four highly heritable traits by numerical taxonomic methods. After implementing a stepwise discriminant analysis, 18 traits were chosen as classificatory variables. Eight population groups were classified in two main clusters. Different morphotypes, primarily associated with panicle architecture and micro floral traits, were found. The patterns in the morphological variation seem to correspond to a gradient of humidity and temperature that diminishes from the NE to the SW. This pattern of classification reflects the geographical origin for most of the sampled populations, although there was some noise. Our results fit the patchy variation model, where populations are genetically selected for macro and micro environmental conditions.Treinta y una poblaciones de Bromus catharticus Vahl., recolectadas en el dominio Pampeano (Argentina, fueron clasificadas utilizando 24 caracteres altamente heredables por métodos de taxonomía numérica. Tras implementar el análisis discriminante del paso a paso (Stepwise, 18 variables fueron seleccionadas como variables clasificatorias. Ocho grupos de poblaciones fueron clasificadas en dos clusters principales. Diferentes morfotipos, principalmente asociados a la arquitectura de las panojas y a variables microflorales, fueron encontrados. El patrón de variación morfológico parece responder a un gradiente de humedad y temperatura que disminuye desde el NE al SW. Además, dicho patrón de clasificación refleja un origen geográfico para la mayoría de las poblaciones, aunque hubo algo de ruido. Nuestros resultados se ajustan a un modelo de variación en parches, donde las poblaciones están genéticamente seleccionadas por condiciones micro y macro ambientales.

  15. Distribution of native Legumes (Leguminoseae) in frequently burned longleaf pine (Pinaceae)-Wiregrass (Poaceae) ecosystems

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    Mark J. Hainds; Robert J. Mitchell; Brian J. Palik; Lindsay R. Boring; Dean H. Gjerstad

    1999-01-01

    Legume species distribution and abundance and selected environmental variables were quantified across a complex gradient (varying in both water-holding capacity and fertility) for frequently burned longleaf pine (Pinus palustris)-wiregrass (Aristida stricta) ecosystems. Legumes were present in all months; however, abundance...

  16. Local climate and cultivation, but not ploidy, predict functional trait variation in Bouteloua gracilis (Poaceae)

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    Butterfield, Bradley J.; Wood, Troy E.

    2015-01-01

    Efforts to improve the diversity of seed 18 resources for important restoration species has become a high priority for land managers in many parts of the world. Relationships between functional trait values and the environment from which seed sources are collected can provide important insights into patterns of local adaptation and guidelines for seed transfer. However, little is known about which functional traits exhibit genetic differentiation across populations of restoration species and thus may contribute to local adaptation. Here, we report the results of a common garden experiment aimed at assessing genetic (including ploidy level) and environmental regulation of several functional traits among populations of Bouteloua gracilis, a dominant C4 grass and the most highly utilized restoration species across much of the Colorado Plateau. We found that leaf size and specific leaf area (SLA) varied significantly among populations, and were strongly correlated with the source population environment from which seeds were collected. However, variation in ploidy level had no significant effect on functional traits. Leaves of plants grown from commercial seed releases were significantly larger and had lower SLA than those from natural populations, a result that is concordant with the overall relation between climate and these two functional traits. We suggest that the patterns of functional trait variation shown here may extend to other grass species in the western USA, and may serve as useful proxies for more extensive genecology research. Furthermore, we argue that care should be taken to develop commercial seed lines with functional trait values that match those of natural populations occupying climates similar to target restoration sites.

  17. Leaf anatomy of the South African Danthonieae (Poaceae. XIII. Pentameris macrocalycina and P. obtusifolia

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    R. P. Ellis

    1984-12-01

    Full Text Available The leaf blade anatomy of Peniameris macrocalycina (Steud. Schweick. and P. obtusifolia (Hochst, Schweick. is described and illustrated. The leaf anatomy of these two species shows many similarities suggesting a close relationship between them. A slight problem appears to exist with the circumscription of P. obtusifolia and a minor taxonomic adjustment may result in a classification which agrees totally with that based on leaf anatomy. This would result in details of the leaf outline being diagnostic for these two taxa. The nomenclature of P. obtusifolia is also very confusing and clarification is needed by reference to the relevant type specimens. P. macrocalycina and P. obtusifolia together with  P. longiglumis (Nees Stapf, appear to form a distinct genus and do not bear close anatomical resemblances to either P. thuarri Beauv. or P. dregeana Stapf.

  18. Chromosomal organization of repetitive DNAs in Hordeum bogdanii and H. brevisubulatum (Poaceae

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    Quanwen Dou

    2016-10-01

    Full Text Available Molecular karyotypes of H. bogdanii Wilensky, 1918 (2n = 14, and H. brevisubulatum Link, 1844 ssp. brevisubulatum (2n = 28, were characterized by physical mapping of several repetitive sequences. A total of 18 repeats, including all possible di- or trinucleotide SSR (simple sequence repeat motifs and satellite DNAs, such as pAs1, 5S rDNA, 45S rDNA, and pSc119.2, were used as probes for fluorescence in situ hybridization on root-tip metaphase chromosomes. Except for the SSR motifs AG, AT and GC, all the repeats we examined produced detectable hybridization signals on chromosomes of both species. A detailed molecular karyotype of the I genome of H. bogdanii is described for the first time, and each repetitive sequence is physically mapped. A high degree of chromosome variation, including aneuploidy and structural changes, was observed in H. brevisubulatum. Although the distribution of repeats in the chromosomes of H. brevisubulatum is different from that of H. bogdanii, similar patterns between the two species imply that the autopolyploid origin of H. brevisubulatum is from a Hordeum species with an I genome. A comparison of the I genome and the other Hordeum genomes, H, Xa and Xu, shows that colocalization of motifs AAC, ACT and CAT and colocalization of motifs AAG and AGG are characteristic of the I genome. In addition, we discuss the evolutionary significance of repeats in the genome during genome differentiation.

  19. Recovery from drought stress in Lolium perenne (Poaceae): are fungal endophytes detrimental?

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    Cheplick, Gregory P

    2004-12-01

    Perennial ryegrass (Lolium perenne) is a cool-season, perennial species widely used for forage and turf. It is often infected by a clandestine, endophytic fungus (Neotyphodium lolii) that has the potential to affect host growth responses to abiotically stressful conditions. In some species, the grass-endophyte symbiosis is mutualistic, but the relationship is reported to be contingent on environmental conditions and host genotype in L. perenne. The objective of this research was to determine the potential effects of endophyte infection on recovery from severe drought stress in variable genotypes of a perennial ryegrass cultivar. Sixteen infected (+E) and 16 uninfected (-E) ramets were planted in the greenhouse for each of 10 ryegrass genotypes. Eight +E and eight -E plants per genotype were exposed to three sequential droughts where water was withheld for 11-14 d, resulting in drought, and leaf area and dry mass of shoots and roots 7 wk after drought. In both control and drought, -E plants had more tillers, and greater leaf area and total mass, than +E plants, suggesting a detrimental effect of endophytic fungi. Fungal hyphae survived the drought and were abundant in post-drought, +E plants. The effects of endophytes were specific for particular host genotypes, as exemplified by significant genotype × endophyte interactions. Root : shoot ratio and percent of mass allocated to tiller bases (a rough measure of resource storage) showed genotype × endophyte × drought interactions. There was plasticity for root : shoot ratio and genetic variation in the ability to restore root growth during recovery from drought. For 7 of 10 genotypes, -E plants showed an equal or greater allocation to tiller bases than +E plants following drought recovery, illustrating a cost to endophyte infection for some genotypes. The symbiotic relationship between L. perenne and its endophyte primarily benefits the fungus, not the host, under many environmental conditions.

  20. Genetic analysis and gene fine mapping of aroma in rice (Oryza sativa L. Cyperales, Poaceae

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    Shu Xia Sun

    2008-01-01

    Full Text Available We investigated inheritance and carried out gene fine mapping of aroma in crosses between the aromatic elite hybrid rice Oryza sativa indica variety Chuanxiang-29B (Ch-29B and the non-aromatic rice O. sativa indica variety R2 and O. sativa japonica Lemont (Le. The F1 grains and leaves were non-aromatic while the F2 non-aroma to aroma segregation pattern was 3:1. The F3 segregation ratio was consistent with the expected 1:2:1 for a single recessive aroma gene in Ch-29B. Linkage analysis between simple sequence repeat (SSR markers and the aroma locus for the aromatic F2 plants mapped the Ch-29B aroma gene to a chromosome 8 region flanked by SSR markers RM23120 at 0.52 cM and RM3459 at 1.23 cM, a replicate F2 population confirming these results. Three bacterial artificial chromosome (BAC clones cover chromosome 8 markers RM23120 and RM3459. Our molecular mapping data from the two populations indicated that the aroma locus occurs in a 142.85 kb interval on BAC clones AP005301 or AP005537, implying that it might be the same gene reported by Bradbury et al (2005a; Plant Biotec J. 3:363-370. The flanking markers Aro7, RM23120 and RM3459 identified by us could greatly accelerate the efficiency and precision of aromatic rice breeding programs.

  1. Phylogenetic relationships of Echinolaena and Ichnanthus within Panicoideae (Poaceae) reveal two new genera of tropical grasses.

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    Silva, Christian; Snak, Cristiane; Schnadelbach, Alessandra Selbach; van den Berg, Cássio; Oliveira, Reyjane Patrícia

    2015-12-01

    Echinolaena and Ichnanthus are two tropical grass genera distributed mostly in the Americas, characterized by the presence of rachilla appendages in the shape of convex swellings, scars or wings at the base of the upper anthecium. However, recent studies have shown that rachilla appendages arose several times independently in several groups within Paniceae and Paspaleae (Panicoideae). Thus, this study aimed to assess the monophyly of Echinolaena and Ichnanthus and their relationship to other genera of Paniceae and Paspaleae, especially those including species with rachilla appendages. Parsimony and Bayesian analyses of the cpDNA regions ndhF, rpl16, trnH-(rps19)-psbA, trnL-trnF, trnS-(psbZ)-trnG, and the rDNA ITS region included 29 of the 39 known species of Echinolaena and Ichnanthus, 23 of which were sampled for the first time. The multiple loci analyses indicated that Echinolaena and Ichnanthus are polyphyletic in their current circumscriptions, with species in four distinct lineages within subtribe Paspalinae, each one characterized by a single type of rachilla appendage. Thus, Echinolaena and Ichnanthus are each circumscribed in a narrow sense, and the other two lineages excluded from them are proposed as the new genera Hildaea and Oedochloa, resulting in 15 new combinations and the restablishment of I. oplismenoides Munro ex Döll.

  2. Geographical distribution of present day Poaceae as evidence for the origin of African floras

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    W. D. Clayton

    1983-12-01

    Full Text Available The major tribes and sub-families of grasses occupy worldwide latitudinal belts, which can be related to an evolutionary sequence of climatic adaptations. However, genera tend to be confined to individual continents, suggesting that grasses do not easily cross the oceans, and that the worldwide distribution of the family may have been achieved when the continents were closer together. Species distributions are likewise strongly influenced by the effect of climatic adaptation and continental isolation, but they show a number of aberrations. These are probably a legacy of climatic disturbance during the Pleistocene.

  3. Phylogenomics and Plastome Evolution of Tropical Forest Grasses (Leptaspis, Streptochaeta: Poaceae).

    Science.gov (United States)

    Burke, Sean V; Lin, Choun-Sea; Wysocki, William P; Clark, Lynn G; Duvall, Melvin R

    2016-01-01

    Studies of complete plastomes have proven informative for our understanding of the molecular evolution and phylogenomics of grasses. In this study, a plastome phylogenomic analysis sampled species from lineages of deeply diverging grasses including Streptochaeta spicata (Anomochlooideae), Leptaspis banksii, and L. zeylanica (both Pharoideae). Plastomes from next generation sequences for three species were assembled by de novo methods. The unambiguously aligned coding and non-coding sequences of the entire plastomes were aligned with those from 43 other grasses and the outgroup Joinvillea ascendens. Outgroup sampling of grasses has previously posed a challenge for plastome phylogenomic studies because of major rearrangements of the plastome. Here, over 81,000 bases of homologous sequence were aligned for phylogenomic and divergence estimation analyses. Rare genomic changes, including persistently long ψycf1 and ψycf2 loci, the loss of the rpoC1 intron, and a 21 base tandem repeat insert in the coding sequence for rps19 defined branch points in the grass phylogeny. Marked differences were seen in the topologies inferred from the complete plastome and two gene matrices, and mean maximum likelihood support values for the former were 10% higher. In the full plastome phylogenomic analyses, the two species of Anomochlooideae were monophyletic. Leptaspis and Pharus were found to be reciprocally monophyletic, with the estimated divergence of two Leptaspis species preceding those of Pharus by over 14 Ma, consistent with historical biogeography. Our estimates for deep divergences among grasses were older than previous such estimates, likely influenced by more complete taxonomic and molecular sampling and the use of recently available or previously unused fossil calibration points.

  4. The evolutionary context of root epidermis cell patterning in grasses (Poaceae).

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    Marzec, Marek; Melzer, Michael; Szarejko, Iwona

    2014-01-01

    In the last century, the mechanism for establishing the root epidermal pattern in grasses was proposed as a differentiating trait that can be used in taxonomic studies and as a useful tool to indicate the relationships between genera. However, knowledge about root hair differentiation in monocots is still scarce. During the last few years, this process has been studied intensively, mainly based on genetics and histological studies. A histological analysis of the root epidermis pattern composed from root hairs (trichoblasts) and non-root hair cells (atrichoblasts), as well as observations of the mechanism of the establishment of this pattern allowed 2 different methods of epidermal cell specialization in monocots to be precisely described. Additionally, a recently published paper describing root hair development in barley shed new light on the evolutionary context of the mechanism of root epidermis cell specialization, which is discussed in the presented work.

  5. The evolutionary context of root epidermis cell patterning in grasses (Poaceae)

    Science.gov (United States)

    Marzec, Marek; Melzer, Michael; Szarejko, Iwona

    2014-01-01

    In the last century, the mechanism for establishing the root epidermal pattern in grasses was proposed as a differentiating trait that can be used in taxonomic studies and as a useful tool to indicate the relationships between genera. However, knowledge about root hair differentiation in monocots is still scarce. During the last few years, this process has been studied intensively, mainly based on genetics and histological studies. A histological analysis of the root epidermis pattern composed from root hairs (trichoblasts) and non-root hair cells (atrichoblasts), as well as observations of the mechanism of the establishment of this pattern allowed 2 different methods of epidermal cell specialization in monocots to be precisely described. Additionally, a recently published paper describing root hair development in barley shed new light on the evolutionary context of the mechanism of root epidermis cell specialization, which is discussed in the presented work. PMID:24521825

  6. Nuclear SSR markers for Miscanthus, Saccharum, and related grasses (Saccharinae, Poaceae)1

    Science.gov (United States)

    Hodkinson, Trevor R.; de Cesare, Mariateresa; Barth, Susanne

    2013-01-01

    • Premise of the study: We developed nuclear simple sequence repeat (SSR) markers for the characterization of the biomass crop Miscanthus, especially M. sacchariflorus, M. sinensis, and M. ×giganteus, and tested for cross-species amplification. • Methods and Results: Twenty-nine SSR markers (di- and tetranucleotide repeats) were developed from DNA sequences obtained from 192 clones from an enriched genomic library of M. sinensis. All markers were successfully amplified in M. sacchariflorus, M. sinensis, and M. ×giganteus, and 19 amplified across a broad range of Miscanthus species. Polymorphism information content and expected heterozygosity values (19 locus sample) were 0.88 and 0.89, respectively, for M. sinensis, 0.48 and 0.54 for M. sacchariflorus, and were the lowest in M. ×giganteus (0.33, 0.41). Thirteen out of 19 primer pairs showed cross-species amplification in non-Miscanthus sensu stricto taxa. • Conclusions: The new set of 29 SSR markers will be of high value for characterizing Miscanthus germplasm collections, for prebreeding, and for assessing variation in natural populations. PMID:25202497

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

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    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.

  8. Genome analysis of 7 Kengyilia (Triticeae Poaceae) species with FISH and GISH

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    Genome composition of and genetic relationships among seven Kengyilia species were assessed using a technique of sequential FISH (fluorescence in situ hybridization) and GISH (genomic in situ hybridization). Five of these 7 species, K. kokonorica, K. rigidula, K. hirsula, K. grandiglumis, and K. th...

  9. Ultraestructura del bambú Guadua macclurei (Poaceae: Bambusoideae de Costa Rica

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    Mayra Montiel

    2006-06-01

    Full Text Available Se evaluaron ultraestructuralmente secciones de la lámina de la hoja, vaina de la hoja y rama, de una planta adulta de Guadua macclurei. Las brácteas del culmo carecen de setas orales. En la superficie adaxial de la lámina foliar se observó un patrón celular diferente al de otras especies de este género. Además, hay tricomas tricelulares y bandas de estomas de alto domo muy ordenadas y evidentes, característica que la podría diferenciar de otras especies en el género. Esta es la primera descripción microscópica de esta especie.We studied the ultrastructure of sections of leaf lamina, leaf sheath and branches of an adult plant of Guadua macclurei. Culm sheaths lack fimbriae (oral setae. The adaxial section of the leaf lamina has a particular cellular pattern, previously unreported in this genus. The tricellular trichomes, and the evident and ordered bands of high dome stomata may be useful for taxonomic purposes. To the best of our knowledge, this is the first microscopic description of this species. Rev. Biol. Trop. 54(Suppl. 2: 35-42. Epub 2006 Dec. 01.

  10. Miocene-Pliocene speciation, introgression, and migration of Patis and Ptilagrostis (Poaceae: Stipeae).

    Science.gov (United States)

    Romaschenko, Konstantin; Garcia-Jacas, Nuria; Peterson, Paul M; Soreng, Robert J; Vilatersana, Roser; Susanna, Alfonso

    2014-01-01

    Genetic interchange between American and Eurasian species is fundamental to our understanding of the biogeographical patterns, and we make a first attempt to reconstruct the evolutionary events in East Asia that lead to the origin and dispersal of two genera, Patis and Ptilagrostis. We conducted a molecular phylogenetic study of 78 species in the tribe Stipeae using four plastid DNA sequences (ndhF, rpl32-trnL, rps16-trnK, and rps16 intron) and two nuclear DNA sequences (ITS and At103). We use single copy nDNA gene At103 for the first time in the grasses to elucidate the evolutionary history among members of the Stipeae. Ampelodesmos, Hesperostipa, Oryzopsis, Pappostipa, Patis, and Stipa are found to be of multiple origins. Our phylograms reveal conflicting positions for Ptilagrostis alpina and Pt. porteri that form a clade with Patis coreana, P. obtusa, and P. racemosa in the combined plastid tree but are aligned with other members of Ptilagrostis in the ITS tree. We hypothesize that Ptilagrostis still retains the nucleotype of an extinct genus which transited the Bering land bridge from American origins in the late Miocene (minimum 7.35-6.37 mya) followed by hybridization and two plastid capture events with a Trikeraia-like taxon (7.96 mya) and para-Patis (between 5.32 and 3.76 mya). Ptilagrostis porteri and Patis racemosa then migrated to continental North America 1.7-2.9 mya and 4.3-5.3 mya, respectively. Published by Elsevier Inc.

  11. Identification of SNP markers for inferring phylogeny in temperate bamboos (Poaceae: Bambusoideae) using RAD sequencing.

    Science.gov (United States)

    Wang, X Q; Zhao, L; Eaton, D A R; Li, D Z; Guo, Z H

    2013-09-01

    Phylogenetic relationships among temperate species of bamboo are difficult to resolve, owing to both the challenge of detecting sufficiently variable markers and their polyploid history. Here, we use restriction site-associated DNA sequencing to identify candidate loci with fixed allelic differences segregating between and within two temperate species of bamboos: Arundinaria faberi and Yushania brevipaniculata. Approximately 27 million paired-end sequencing reads were generated across four samples. From pooled data, we assembled 67 685 and 70 668 de novo contigs from partial overlap among paired-end reads, with an average length of 240 and 241 bp for the two species, respectively, which were used to investigate functional classification of RAD tags in a blastx search. Analysed separately by population, we recovered 29 443 putatively orthologous RAD tags shared across the four sampled populations, containing 28 023 sequence variants, of which c. 13 000 are segregating between species, and c. 3000 segregating between populations within each species. Analyses based on these RAD tags yielded robust phylogenetic inferences, even with data set constructed from surprisingly few loci. This study illustrates the potential for reduced-representation genome data to resolve difficult phylogenetic relationships in temperate bamboos. © 2013 John Wiley & Sons Ltd.

  12. The floral transcriptomes of four bamboo species (Bambusoideae; Poaceae): support for common ancestry among woody bamboos.

    Science.gov (United States)

    Wysocki, William P; Ruiz-Sanchez, Eduardo; Yin, Yanbin; Duvall, Melvin R

    2016-05-20

    Next-generation sequencing now allows for total RNA extracts to be sequenced in non-model organisms such as bamboos, an economically and ecologically important group of grasses. Bamboos are divided into three lineages, two of which are woody perennials with bisexual flowers, which undergo gregarious monocarpy. The third lineage, which are herbaceous perennials, possesses unisexual flowers that undergo annual flowering events. Transcriptomes were assembled using both reference-based and de novo methods. These two methods were tested by characterizing transcriptome content using sequence alignment to previously characterized reference proteomes and by identifying Pfam domains. Because of the striking differences in floral morphology and phenology between the herbaceous and woody bamboo lineages, MADS-box genes, transcription factors that control floral development and timing, were characterized and analyzed in this study. Transcripts were identified using phylogenetic methods and categorized as A, B, C, D or E-class genes, which control floral development, or SOC or SVP-like genes, which control the timing of flowering events. Putative nuclear orthologues were also identified in bamboos to use as phylogenetic markers. Instances of gene copies exhibiting topological patterns that correspond to shared phenotypes were observed in several gene families including floral development and timing genes. Alignments and phylogenetic trees were generated for 3,878 genes and for all genes in a concatenated analysis. Both the concatenated analysis and those of 2,412 separate gene trees supported monophyly among the woody bamboos, which is incongruent with previous phylogenetic studies using plastid markers.

  13. NOVEDADES AGROSTOLÓGICAS PARA COLOMBIA Y PERÚ: AXONOPUS Y DIGITARIA (POACEAE: PANICOIDEAE

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    DIEGO GIRALDO-CAÑAS

    2013-12-01

    Full Text Available Como resultado de recientes estudios en gramíneas neotropicales, se propone y se ilustra una nueva especie de Axonopus. Con esta nueva especie, el género queda representado en la flora colombiana por 19 especies. Por otra parte, se registra por primera vez para el Perú a Digitaria abyssinica (Hochst. ex A. Rich. Stapf. Con este nuevo registro, Digitaria queda representado en la flora peruana por 18 especies.

  14. Comparative Foliar Epidermal Studies in Coix lacryma-jobi L. andCoix aquatica Roxb. (Poaceae

    Directory of Open Access Journals (Sweden)

    Rinku Jitendrakumar DESAI

    2009-12-01

    Full Text Available As micromorphological knowledge was not available for Coix aquatica Roxb., the foliar epidermal studies were carried out for Coix lacryma-jobi L. and Coix aquatica Roxb. with the aim of determining the patterns of variation in their epidermal characteristics and assessing their value in species identification. Comparative foliar analysis was carried out by using light microscopy, after following routine scraping method. The characters of diagnostic importance in the identification of C. aquatica are the sparsely distributed prickle hairs with long pointed apex in the abaxial epidermis and dumbbell shaped silica cells in both the epidermises. The diagnostic characters for C. lacryma-jobi are the cross shaped silica cells and dumbbell shaped on the abaxial and adaxial epidermis respectively. The observed differences in certain micromorphological characters helps in identification of presently studied two species of Coix.

  15. The complete chloroplast genome sequence of the Bambusa multiplex (Poaceae: Bambusoideae).

    Science.gov (United States)

    Gao, Ju; Li, Kui; Gao, Li-zhi

    2016-01-01

    The complete nucleotide sequence of the Bambusa multiplex chloroplast genome (cpDNA) was determined in this study. The cpDNA was 139,394 bp in length, containing a pair of 21,798 bp inverted repeat regions (IR), which were separated by small and large single copy regions (SSC and LSC) of 12,875 and 82,923 bp, respectively. The B. multiplex cp genome encodes 129 predicted functional genes; 110 are unique (77 protein-coding genes, 29 tRNA genes, 4 rRNA), 19 are duplicated in the IR regions and one gene extended into the IR region in the junctions between IR and SSC. 43.20% of the genome sequence encodes proteins. The B. multiplex cp genome is AT-rich (61.08%). In these genes, fourteen genes contained one intron, while one gene had two introns.

  16. Evolutionary pattern of rDNA following polyploidy in Leymus (Triticeae: Poaceae).

    Science.gov (United States)

    Fan, Xing; Liu, Jing; Sha, Li-Na; Sun, Gen-Lou; Hu, Zhi-Qin; Zeng, Jian; Kang, Hou-Yang; Zhang, Hai-Qin; Wang, Yi; Wang, Xiao-Li; Zhang, Li; Ding, Chun-Bang; Yang, Rui-Wu; Zheng, You-Liang; Zhou, Yong-Hong

    2014-08-01

    Ribosomal ITS polymorphism and its ancestral genome origin of polyploid Leymus were examined to infer the evolutionary outcome of rDNA gene following allopolyploid speciation and to elucidate the geographic pattern of ITS variation. The results demonstrated that different polyploids have experienced varying fates, including maintenance or homogenization of divergent arrays, occurrence of chimeric repeats and potential pseudogenes. Our data suggested that (1) the Ns, P/F, and St genomic types in Leymus were originated from Psathyrostachys, Agropyron/Eremopyrum, and Pseudoroegneria, respectively; (2) the occurrence of a higher proportion of Leymus species with predominant uniparental rDNA type might associate with the segmental allopolyploid origin, nucleolar dominance of alloploids, and rapid radiation of Leymus; (3) maintenance of multiple parental ITS types in allopolyploid might result from long generation times associated to vegetative multiplication, number and chromosomal location of ribosomal loci and/or recurrent hybridization; (4) the rDNA genealogical structure of Leymus species might associate with the geographic origins; and (5) ITS sequence clade shared by Leymus species from Central Asia, North America, and Nordic might be an outcome of ancestral ITS homogenization. Our results shed new light on understanding evolutionary outcomes of rDNA following allopolyploid speciation and geographic isolation. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Isolation and characterization of microsatellite markers for Axonopus compressus (Sw.) Beauv. (Poaceae) using 454 sequencing technology.

    Science.gov (United States)

    Wang, X-L; Li, Y; Liao, L; Bai, C-J; Wang, Z-Y

    2015-05-11

    Axonopus compressus (Sw.) Beauv. is a perennial herb widely used as a garden lawn grass. In this study, we used Roche 454 pyrosequencing, combined with the magnetic bead enrichment method FIASCO, to isolate simple sequence repeat markers from the A. compressus genome. A total of 1942 microsatellite loci were identified, with 53,193 raw sequencing reads. One hundred micro-satellite loci were selected to test the primer amplification efficiency in 24 individuals; 14 primer pairs yielded polymorphic amplification products. The number of observed alleles ranged from two to six, with an average of 3.5. Shannon's Information index values ranged from 0.169 to 0.650, with an average of 0.393. Nei's genetic diversity values ranged from 0.108 to 0.457, with an average of 0.271. This first set of microsatellite markers developed for Axonopus will assist in the development of molecular marker-assisted breeding and the assessment of genetic diversity in A. compressus.

  18. Phylogenetic estimation and morphological evolution of Arundinarieae (Bambusoideae: Poaceae) based on plastome phylogenomic analysis.

    Science.gov (United States)

    Attigala, Lakshmi; Wysocki, William P; Duvall, Melvin R; Clark, Lynn G

    2016-08-01

    We explored phylogenetic relationships among the twelve lineages of the temperate woody bamboo clade (tribe Arundinarieae) based on plastid genome (plastome) sequence data. A representative sample of 28 taxa was used and maximum parsimony, maximum likelihood and Bayesian inference analyses were conducted to estimate the Arundinarieae phylogeny. All the previously recognized clades of Arundinarieae were supported, with Ampelocalamus calcareus (Clade XI) as sister to the rest of the temperate woody bamboos. Well supported sister relationships between Bergbambos tessellata (Clade I) and Thamnocalamus spathiflorus (Clade VII) and between Kuruna (Clade XII) and Chimonocalmus (Clade III) were revealed by the current study. The plastome topology was tested by taxon removal experiments and alternative hypothesis testing and the results supported the current plastome phylogeny as robust. Neighbor-net analyses showed few phylogenetic signal conflicts, but suggested some potentially complex relationships among these taxa. Analyses of morphological character evolution of rhizomes and reproductive structures revealed that pachymorph rhizomes were most likely the ancestral state in Arundinarieae. In contrast leptomorph rhizomes either evolved once with reversions to the pachymorph condition or multiple times in Arundinarieae. Further, pseudospikelets evolved independently at least twice in the Arundinarieae, but the ancestral state is ambiguous. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Confirmed field hybridization of native and introduced Phragmites australis (Poaceae) in North America.

    Science.gov (United States)

    Saltonstall, Kristin; Castillo, Hilda E; Blossey, Bernd

    2014-01-01

    Intraspecific hybridization between native and introduced lineages of a species can increase invasiveness and may lead to the decline of native lineages. The introduction of Eurasian Phragmites australis has caused profound changes to wetland habitats across North America, yet evidence for hybridization between native and introduced Phragmites australis in North America is lacking and has puzzled researchers for over a decade. Here we present the first confirmed field hybridization event between the two lineages. Hybrid plants were initially recognized during field surveys by their intermediate morphology and distinct herbivore community. We verified hybrid status using chloroplast DNA haplotypes and microsatellite markers. Confirmed hybrid stems were restricted to one site and displayed morphological characteristics of both native and introduced P. australis. Based on their microsatellite profiles, all samples likely represent a single clone of a first generation hybrid. Sequencing of cpDNA indicates that the maternal parent is from the introduced lineage. Identification of hybrid P. australis in the field is complex and requires multiple characters. All suspected hybrids should be verified using genetic techniques. Preventing the spread of introduced genes and genotypes through North America will require recognition and rapid management response to hybrid plants.

  20. 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.

  1. Changes in tussock architecture of invasive Spartina densiflora (Poaceae) along the Pacific Coast of North America

    Science.gov (United States)

    It is important to link functional trait-based responses of invaders to environmental changes to improve our understanding of mechanisms that promote invasiveness. The invasion of alien Spartina densiflora Brongn. along the Pacific coast of North America provides a natural model system for studying ...

  2. Genome analysis of seven species of Kengyilia (Triticeae: Poaceae) with FISH and GISH.

    Science.gov (United States)

    Dou, Quanwen; Wang, Richard R-C; Lei, Yuting; Yu, Feng; Li, Yuan; Wang, Haiqing; Chen, Zhiguo

    2013-11-01

    The genome compositions and genetic relationships of seven species of Kengyilia were assessed using a sequential fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) technique. Five species, K. kokonorica, K. rigidula, K. hirsuta, K. grandiglumis, and K. thoroldiana, are native to Qinghai (China). The other two, K. alatavica and K. batalinii, are distributed in Xinjiang (China) and Kyrgyzstan, respectively. Each chromosome could be easily identified using chromosome markers (45S rDNA, 5S rDNA, pAs1, and AAG repeats) by FISH and allocated to the St, P, or Y genome by GISH. Molecular karyotype comparison indicated that K. alatavica and K. batalinii were distinct from the Qinghai species in all three genomes. These results support that the species of Kengyilia from Central Asia and the Qinghai-Tibetan plateau have independent origins. Genomic differentiation was still detected among the species of Kengyilia from Qinghai. Specifically, a common species-specific pericentric inversion was identified in both K. grandiglumis and K. thoroldiana, and an identical St-P non-Robertsonian translocation was frequently detected in K. hirsuta. The Qinghai species formed three genetic groups, K. kokonorica-K. rigidula, K. hirsuta, and K. grandiglumis-K. thoroldiana. The possible role of species-specific inversions and translocations in the evolution of StPY species is discussed.

  3. Germination of Saccharum ravennae(L.)L.(Poaceae) caryopses and intact spikelets

    Science.gov (United States)

    Ravenna grass, Saccharum ravennae (L.) L., is a robust perennial bunchgrass grown as an ornamental in the United States, but where adapted, has become naturalized in riparian areas. Little is known about the seed size distribution and germination characteristics of caryopses and intact spikelets. ...

  4. On the cellular site of two-pore channel TPC1 action in the Poaceae.

    Science.gov (United States)

    Dadacz-Narloch, Beata; Kimura, Sachie; Kurusu, Takamitsu; Farmer, Edward E; Becker, Dirk; Kuchitsu, Kazuyuki; Hedrich, Rainer

    2013-11-01

    The slow vacuolar (SV) channel has been characterized in different dicots by patch-clamp recordings. This channel represents the major cation conductance of the largest organelle in most plant cells. Studies with the tpc1-2 mutant of the model dicot plant Arabidopsis thaliana identified the SV channel as the product of the TPC1 gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium-permeable channel. To explore the site of action of grass TPC1 channels, we expressed OsTPC1 from rice (Oryza sativa) and TaTPC1 from wheat (Triticum aestivum) in the background of the Arabidopsis tpc1-2 mutant. Cross-species tpc1 complementation and patch-clamping of vacuoles using Arabidopsis and rice tpc1 null mutants documented that both monocot TPC1 genes were capable of rescuing the SV channel deficit. Vacuoles from wild-type rice but not the tpc1 loss-of-function mutant harbor SV channels exhibiting the hallmark properties of dicot TPC1/SV channels. When expressed in human embryonic kidney (HEK293) cells OsTPC1 was targeted to Lysotracker-Red-positive organelles. The finding that the rice TPC1, just like those from the model plant Arabidopsis and even animal cells, is localized and active in lyso-vacuolar membranes associates this cation channel species with endomembrane function. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  5. The effect of the external medium on the gravitropic curvature of rice (Oryza sativa, Poaceae) roots

    Science.gov (United States)

    Staves, M. P.; Wayne, R.; Leopold, A. C.

    1997-01-01

    The roots of rice seedlings, growing in artificial pond water, exhibit robust gravitropic curvature when placed perpendicular to the vector of gravity. To determine whether the statolith theory (in which intracellular sedimenting particles are responsible for gravity sensing) or the gravitational pressure theory (in which the entire protoplast acts as the gravity sensor) best accounts for gravity sensing in rice roots, we changed the physical properties of the external medium with impermeant solutes and examined the effect on gravitropism. As the density of the external medium is increased, the rate of gravitropic curvature decreases. The decrease in the rate of gravicurvature cannot be attributed to an inhibition of growth, since rice roots grown in 100 Osm/m3 (0.248 MPa) solutions of different densities all support the same root growth rate but inhibit gravicurvature increasingly with increasing density. By contrast, the sedimentation rate of amyloplasts in the columella cells is unaffected by the external density. These results are consistent with the gravitational pressure theory of gravity sensing, but cannot be explained by the statolith theory.

  6. Ptilagrostis contracta (Stipeae, Poaceae), a New Species Endemic to Qinghai-Tibet Plateau.

    Science.gov (United States)

    Zhang, Zhong-Shuai; Li, Ling-Lu; Chen, Wen-Li

    2017-01-01

    A new species, Ptilagrostis contracta, endemic to Qinghai-Tibet Plateau is described and illustrated. It is distinguished from other species in Ptilagrostis by having contracted panicles, 1-geniculate awns with hairy columns and scabrous bristles and evenly pubescent lemmas. Evidence from lemma epidermal pattern, cytology and molecular phylogenetic analyses based on the nuclear ITS sequence data confirm its systematic position in Ptilagrostis.

  7. Geographical distribution of present day Poaceae as evidence for the origin of African floras

    Directory of Open Access Journals (Sweden)

    W. D. Clayton

    1983-12-01

    Full Text Available The major tribes and sub-families of grasses occupy worldwide latitudinal belts, which can be related to an evolutionary sequence of climatic adaptations. However, genera tend to be confined to individual continents, suggesting that grasses do not easily cross the oceans, and that the worldwide distribution of the family may have been achieved when the continents were closer together. Species distributions are likewise strongly influenced by the effect of climatic adaptation and continental isolation, but they show a number of aberrations. These are probably a legacy of climatic disturbance during the Pleistocene.

  8. Identification of putative orthologous genes for the phylogenetic reconstruction of temperate woody bamboos (Poaceae: Bambusoideae).

    Science.gov (United States)

    Zhang, Li-Na; Zhang, Xian-Zhi; Zhang, Yu-Xiao; Zeng, Chun-Xia; Ma, Peng-Fei; Zhao, Lei; Guo, Zhen-Hua; Li, De-Zhu

    2014-09-01

    The temperate woody bamboos (Arundinarieae) are highly diverse in morphology but lack a substantial amount of genetic variation. The taxonomy of this lineage is intractable, and the relationships within the tribe have not been well resolved. Recent studies indicated that this tribe could have a complex evolutionary history. Although phylogenetic studies of the tribe have been carried out, most of these phylogenetic reconstructions were based on plastid data, which provide lower phylogenetic resolution compared with nuclear data. In this study, we intended to identify a set of desirable nuclear genes for resolving the phylogeny of the temperate woody bamboos. Using two different methodologies, we identified 209 and 916 genes, respectively, as putative single copy orthologous genes. A total of 112 genes was successfully amplified and sequenced by next-generation sequencing technologies in five species sampled from the tribe. As most of the genes exhibited intra-individual allele heterozygotes, we investigated phylogenetic utility by reconstructing the phylogeny based on individual genes. Discordance among gene trees was observed and, to resolve the conflict, we performed a range of analyses using BUCKy and HybTree. While caution should be taken when inferring a phylogeny from multiple conflicting genes, our analysis indicated that 74 of the 112 investigated genes are potential markers for resolving the phylogeny of the temperate woody bamboos. © 2014 John Wiley & Sons Ltd.

  9. Intergeneric hybridization and C-banding patterns in Hordelymus (Triticeae, Poaceae)

    DEFF Research Database (Denmark)

    Bothmer, R. von; Lu, B.-R.; Linde-Laursen, I.

    1994-01-01

    Crosses of Hordelymus europaeus (2n = 4x = 28) with four genera in the Triticeae were attempted. Adult hybrids were obtained in combinations with Hordeum bogdanii (2x), Hordeum depressum (4x), and Secale cereale (2x). The meiotic pairing was very low in the hybrids with H. bogdanii and Secale cer...

  10. The utility of Bambusoideae (Poaceae, Poales) leaf blade anatomy for identification and systematics.

    Science.gov (United States)

    Leandro, T D; Shirasuna, R T; Filgueiras, T S; Scatena, V L

    2016-04-19

    Bambusoideae is a diverse subfamily that includes herbaceous (Olyreae) and woody (Arundinarieae and Bambuseae) bamboos. Species within Bambusae are particularly difficult to identify due to their monocarpic lifecycle and the often long durations between mass flowering events; whereas the herbaceous bamboos are pluricarpic, but often are found with no reproductive structures. The leaf blade anatomy of 16 sympatric species of native Brazilian bamboos (Olyreae and Bambuseae) from the Atlantic Rainforest was studied in order to detect useful features for their identification. All the studied species share the following features: epidermis with a single stratum of cells; adaxial bulliform cells; mesophyll with arm cells, rosette cells, and fusoid cells; and collateral vascular bundles. Herbaceous bamboos share two features: papillae scattered on the abaxial surface and parallel-sided arrays of bulliform cells; whereas woody bamboos share: centrally organized papillae and fan-shaped arrays of bulliform cells. Also within the woody bamboos, intercostal fibers and a midrib with only one vascular bundle (simple midrib) characterize the subtribe Arthrostylidiinae; whereas a midrib with more than one vascular bundle (complex midrib) and a stomatal apparatus with two pappilae per subsidiary cell characterize the subtribe Chusqueinae. There are also diagnostic features for the sampled species, such as: papillae shape, and the outline and structure of the midrib. An identification key for all the studied species is provided based on the anatomical features.

  11. Multilocus species tree analyses resolve the ancient radiation of the subtribe Zizaniinae (Poaceae).

    Science.gov (United States)

    Tang, Liang; Zou, Xin-hui; Zhang, Lin-bin; Ge, Song

    2015-03-01

    The phylogeny of the subtribe Zizaniinae of rice tribe (Oryzeae) has not been well resolved, particularly for the monotypic Hygroryza whose systematic position was inconsistent in previous studies. Here, we used the concatenation approach and coalescent-based species tree methods to reconstruct the phylogeny of Zizaniinae based on sequences of 14 nuclear single-copy loci and concatenated chloroplast fragments. Despite the low resolution of the tree from concatenated data and substantial topological incongruence of individual gene trees, the species trees inferred from three coalescent-based methods were fully concordant and highly supported. Importantly, the genus Hygroryza was consistently recovered with strong support by all coalescent-based methods. Further various phylogenetic analyses indicated that incomplete lineage sorting was the most likely process that generated pervasive discordance among individual gene trees, although hybridization and introgression cannot be excluded completely. Our species tree inferences based on multilocus data successfully resolved the phylogenetic relationships of the Zizaniinae lineages and confirmed that ancient rapid radiation has taken place in the diversification history of Zizaniinae. This study demonstrates that coalescent-based species tree approaches outperformed the concatenation method and could effectively decipher ancient rapid radiations as long as well resolved individual gene trees were sufficiently sampled. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Merging Fargesia dracocephala into Fargesia decurvata (Bambusoideae, Poaceae): implications from morphological and ITS sequence analyses.

    Science.gov (United States)

    Zhang, Yu-Qu; Wang, Xu-Mei; Wu, A-Li; Ren, Yi

    2014-01-01

    Fargesia decurvata is closely allied with F. dracocephala and differs in 5 major characters (i.e. the culm sheath blade base shape, the width of the culm sheath blade base, the auricle shape, and the lower surface of leaf blade) in Fargesia. It is difficult to distinguish these two species because of existing of transitional statements of characters. The aims of this paper are to (i) investigate whether the variation of the characters is continuous or not; (ii) reveal whether the publishment of F. dracocephala was the result of discontinuous sampling of F. decurvata or not. Ten populations of F. decurvata and F. dracocephala were investigated in their entire distribution (including type localities). The statements of 5 major characters were measured from 693 annual and 693 perennial culms of 231 individuals in 10 populations, and analyzed at population, individual and culm levels. UPGMA cluster analysis was carried out based on 29 characters from 10 populations of F. decurvata and F. dracocephala and 2 populations of F. qinlingensis as outgroup. The ITS sequences were also sequenced and analyzed. Five major characters exhibited great variation not only at population level, but at individual level within a population, even the culm level within an individual and in different parts of the same culm. Cluster analyses showed that 10 populations of F. decurvata and F. dracocephala were not divided into two species, but they were well separated with outgroup. There was no difference in floral organ between F. decurvata and F. dracocephala. MP and NJ trees based on ITS sequences showed the same results with the cluster analysis on morphological characters. All the facts indicated that the publishment of F. dracocephala was the result of discontinuous sampling of F. decurvata, and F. dracocephala should be treated as the synonym of F. decurvata.

  13. Hybridization between invasive Spartina Densiflora (Poaceae) and native S. Foliosa in San Francisco Bay, California, USA

    Science.gov (United States)

    Rapid evolution in contemporary time can result when related species, brought together through human-aided introduction, hybridize. The evolutionary consequences of post introduction hybridization range from allopolyploid speciation to extinction of species through genetic amalg...

  14. ACERCA DE LA IDENTIDAD DE DIGITARIA ANDICOLA Y DIGITARIA CUATRECASASII (POACEAE: PANICOIDEAE: PANICEAE

    Directory of Open Access Journals (Sweden)

    MEDINA MERCHÁN MÓNICA

    2006-06-01

    Full Text Available Se confirma la identidad de Digitaria andicola, se precisan sus caracteres diagósticosy se discuten sus afinidades con las especies Digitaria curtigluma y Digitariacurvinervis. Asimismo, es cuestionada la identidad de Digitaria cuatrecasasii, dandocomo resultado la reducción de este último binomio a la sinonimia de Digitariaandicola.

  15. New species and taxonomic changes within Pentaschistis (Danthonioideae, Poaceae from Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    C. A. Galley

    2006-12-01

    Full Text Available Three new species of Pentaschistis (Nees Stapf are described from the Cape Floristic Region. P. trifida. P clavata and P. horrida. The former has been collected from inland ranges of the Cape Fold Belt, from the Cederberg to the Groot Swartberg. the last two each from single sites in the Koue Bokkeveld:  P. clavata on the wetter western border, and P. horrida on the Baviaansberg. Pentaschistis juncifolia Stapf is re-instated, a species from the coastal plains (Hardeveld between Bredasdorp and Riversdale, which had been included in P. eriostoma (Nees Stapf.

  16. Microsatellite markers for Urochloa humidicola (Poaceae) and their transferability to other Urochloa species.

    Science.gov (United States)

    Santos, Jean C S; Barreto, Mariana A; Oliveira, Fernanda A; Vigna, Bianca B Z; Souza, Anete P

    2015-03-15

    Urochloa humidicola is a warm-season grass commonly used as forage in the tropics and is recognized for its tolerance to seasonal flooding. This grass is an important forage species for the Cerrado and Amazon regions of Brazil. U. humidicola is a polyploid species with variable ploidy (6X-9X) and facultative apomixis with high phenotypic plasticity. However, this apomixis and ploidy, as well as the limited knowledge of the genetic basis of the germplasm collection, have constrained genetic breeding activities, yet microsatellite markers may enable a better understanding of the species' genetic composition. This study aimed to develop and characterize new polymorphic microsatellite molecular markers in U. humidicola and to evaluate their transferability to other Urochloa species. A set of microsatellite markers for U. humidicola was identified from two new enriched genomic DNA libraries: the first library was constructed from a single sexual genotype and the second from a pool of eight apomictic genotypes selected on the basis of previous results. Of the 114 loci developed, 72 primer pairs presented a good amplification product, and 64 were polymorphic among the 34 genotypes tested. The number of bands per simple sequence repeat (SSR) locus ranged from 1 to 29, with a mean of 9.6 bands per locus. The mean polymorphism information content (PIC) of all loci was 0.77, and the mean discrimination power (DP) was 0.87. STRUCTURE analysis revealed differences among U. humidicola accessions, hybrids, and other Urochloa accessions. The transferability of these microsatellites was evaluated in four species of the genus, U. brizantha, U. decumbens, U. ruziziensis, and U. dictyoneura, and the percentage of transferability ranged from 58.33% to 69.44% depending on the species. This work reports new polymorphic microsatellite markers for U. humidicola that can be used for breeding programs of this and other Urochloa species, including genetic linkage mapping, quantitative trait loci identification, and marker-assisted selection.

  17. Leaf anatomy of the South African Danthonieae (Poaceae. III. Merxmuellera stricta

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1980-12-01

    Full Text Available The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera stricta (Schrad. Conert is described and illustrated. In this variable species four distinct anatomical “forms” are recognized viz. the typical  M. stricta form, the Cathedral Peak form, the Drakensberg form and the alpine form. The alpine and Cathedral Peak forms have recently been described as M. guillarmodiae Conert (1975. The degree of anatomical differentiation of these “forms” resembles the situation described in M. disticha (Nees Conert (Ellis, 1980. Populations of both M. stricta and M. disticha from the Drakensberg mountains display extensive anatomical diversification which appears to be correlated with environmental factors. In addition, morphological differences are exhibited as well and the anatomical “forms” of M. stricta probably warrant taxonomic recognition.

  18. Genes and QTLs controlling inflorescence and culm branch architecture in Leymus (Poaceae: Triticeae) wildrye

    Science.gov (United States)

    Grass inflorescence and stem branches show recognizable architectural differences among species. The inflorescence branches of Triticeae cereals and grasses including wheat, barley, and 400-500 wild species are usually contracted into a spike formation with the number of flowering branches (spikele...

  19. Disentangling methodological and biological sources of gene tree discordance on oryza (poaceae) chromosome 3

    Science.gov (United States)

    We describe new methods for characterizing gene tree discordance in phylogenomic datasets, which screen for deviations from neutral expectations, summarize variation in statistical support among gene trees, and allow comparison of the patterns of discordance induced by various analysis choices. Usin...

  20. The complete chloroplast genome sequence of the Phyllostachys sulphurea (Poaceae: Bambusoideae).

    Science.gov (United States)

    Gao, Ju; Gao, Li-zhi

    2016-01-01

    The complete nucleotide sequence of the Phyllostachys sulphurea chloroplast genome (cpDNA) was determined in this study. The cpDNA was 139,731 bp in length, containing a pair of 21,798 bp inverted repeat regions (IR), which were separated by small and large single copy regions (SSC and LSC) of 12,879 and 83,256 bp, respectively. The P. sulphurea cp genome encodes 129 predicted functional genes; 110 are unique (77 protein-coding genes, 29 tRNA genes, 4 rRNA), 19 are duplicated in the IR regions and one gene extended into the IR region in the junctions between IR and SSC. 43.06% of the genome sequence encodes proteins. The P. sulphurea cp genome is AT-rich (61.11%). In these genes, fourteen genes contained one intron, while one gene had two introns.

  1. Comparative phylogeography of the wild-rice genus Zizania (Poaceae) in eastern Asia and North America.

    Science.gov (United States)

    Xu, Xin-Wei; Wu, Jin-Wei; Qi, Mei-Xia; Lu, Qi-Xiang; Lee, Peter F; Lutz, Sue; Ge, Song; Wen, Jun

    2015-02-01

    Comparative phylogeography of intercontinental disjunct taxa allowed us not only to elucidate their diversification and evolution following geographic isolation, but also to understand the effect of climatic and geological histories on the evolutionary processes of closely related species. A phylogeographic analysis was conducted on the eastern Asian-North American disjunct genus Zizania to compare intracontinental phylogeographic patterns between different continents. Surveys were conducted of 514 individuals using three chloroplast DNA fragments and three nuclear microsatellite loci. These individuals included 246 from 45 populations of Zizania latifolia in eastern Asia, and the following from North America: 154 individuals from 26 populations of Z. aquatica, 84 individuals from 14 populations of Z. palustris, and 30 individuals from one population of Z. texana. The genetic diversity of North American Zizania was significantly higher than that of eastern Asian Zizania. High levels of genetic differentiation among populations and no signal of population expansion were detected in three widespread species. No phylogeographic structure was observed in Z. latifolia, and discordant patterns of cpDNA and microsatellite markers were observed in North American Zizania. Reduced variation in Zizania latifolia likely reflects its perennial life history, the North American origin of Zizania, and the relative homogeneity of aquatic environments. High levels of genetic differentiation suggest limited dispersal among populations in all Zizania species. The more complex patterns of diversification and evolution in North American Zizania may be driven by the greater impact of glaciation in North America relative to eastern Asia. © 2015 Botanical Society of America, Inc.

  2. DNA barcoding of western North American taxa: Leymus (Poaceae) and Lepidium (Brassicaceae)

    Science.gov (United States)

    Catherine Mae Culumber

    2007-01-01

    My objective was to determine if polymorphic information from the 18S-5.8S-26S nuclear ribosomal DNA internal transcribed spacer regions and the trnK-psbA, trnK-rps16 chloroplast DNA spacer regions is sufficient 1) to identify a plant specimen to the species level, and 2) to establish the phylogenetic relationship between species. The first study examined the...

  3. Ecological genetics of the Bromus tectorum (Poaceae) - Ustilago Bullata (Ustilaginaceae): A role for frequency dependent selection?

    Science.gov (United States)

    Susan E. Meyer; David L. Nelson; Suzette Clement; Alisa Ramakrishnan

    2010-01-01

    Evolutionary processes that maintain genetic diversity in plants are likely to include selection imposed by pathogens. Negative frequency-dependent selection is a mechanism for maintenance of resistance polymorphism in plant - pathogen interactions. We explored whether such selection operates in the Bromus tectorum - Ustilago bullata pathosystem. Gene-for-gene...

  4. Leaf anatomy of the South African Danthonieae (Poaceae. XVI. The genus Urochlaena

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1988-12-01

    Full Text Available The leaf blade anatomy of Urochlaena pusilla Nees is described and illustrated. The transectional anatomy is non- Kranz with diffuse but uniformly distributed chlorenchyma. The abaxial epidermis has dome-shaped stomata, dumbbell­shaped silica bodies, elongated finger-like microhairs, and cushion-based macrohairs may or may not be present. This type of arundinoid anatomy closely resembles that o f  Tribolium Desv.,  Chaetobromus Nees,  Schismus Beauv., and certain species of Pentaschistis Stapf.  Urochlaena pusilla is very similar to  Tribolium utriculosum (Nees Renv. in leaf anatomy and these two species appear to be closely related.

  5. Taxonomy and leaf anatomy of the genus Ehrharta (Poaceae in southern Africa: the Ramosa group

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    G. E. Gibbs Russel

    1989-12-01

    Full Text Available The Ramosa species group in the genus Ehrharta is distinguished morphologically by small spikelets with sterile lemmas similar to each other, with tips rounded, truncate or mucronate, with sides glabrous, scabrous or shortly hairy, and with bases appendaged and usually bearded. The rectangular intercostal long cells with sinuous walls, the dome-shaped stomata with a raised rim surrounding the pore aperture, the absence of epicuticular wax and the microhairs without a tapering distal cell are diagnostic anatomically. The Ramosa group is composed of two species: E. ramosa (Thunb. Swartz subsp.  ramosa, subsp.  aphylla (Schrad. Gibbs Russell and  E. rehmannii Stapf subsp.  rehmannii; subsp. filiformis (Nees Gibbs Russell; subsp.  subspicata (Stapf Gibbs Russell. All taxa are linked by intermediates to one or two others in the group. The closest relationship of the Ramosa group is to the Calyeina species group, on the basis of both morphological and anatomical characters.

  6. Contrasting bacterial communities in two indigenous Chionochloa (Poaceae) grassland soils in New Zealand.

    Science.gov (United States)

    Griffith, Jocelyn C; Lee, William G; Orlovich, David A; Summerfield, Tina C

    2017-01-01

    The cultivation of grasslands can modify both bacterial community structure and impact on nutrient cycling as well as the productivity and diversity of plant communities. In this study, two pristine New Zealand grassland sites dominated by indigenous tall tussocks (Chionochloa pallens or C. teretifolia) were examined to investigate the extent and predictability of variation of the bacterial community. The contribution of free-living bacteria to biological nitrogen fixation is predicted to be ecologically significant in these soils; therefore, the diazotrophic community was also examined. The C. teretifolia site had N-poor and poorly-drained peaty soils, and the C. pallens had N-rich and well-drained fertile soils. These soils also differ in the proportion of organic carbon (C), Olsen phosphorus (P) and soil pH. The nutrient-rich soils showed increased relative abundances of some copiotrophic bacterial taxa (including members of the Proteobacteria, Bacteroidetes and Firmicutes phyla). Other copiotrophs, Actinobacteria and the oliogotrophic Acidobacteria showed increased relative abundance in nutrient-poor soils. Greater diversity based on 16S rRNA gene sequences and the Tax4Fun prediction of enhanced spore formation associated with nutrient-rich soils could indicate increased resilience of the bacterial community. The two sites had distinct diazotrophic communities with higher diversity in C. teretifolia soils that had less available nitrate and ammonium, potentially indicating increased resilience of the diazotroph community at this site. The C. teretifolia soils had more 16S rRNA gene and nifH copies per g soil than the nutrient rich site. However, the proportion of the bacterial community that was diazotrophic was similar in the two soils. We suggest that edaphic and vegetation factors are contributing to major differences in the composition and diversity of total bacterial and diazotrophic communities at these sites. We predict the differences in the communities at the two sites will result in different responses to environmental change.

  7. Molecular evolution and nucleotide diversity of nuclear plastid phosphoglycerate kinase (PGK) gene in Triticeae (Poaceae).

    Science.gov (United States)

    Adderley, Shawn; Sun, Genlou

    2014-01-01

    Levels of nucleotide divergence provide key evidence in the evolution of polyploids. The nucleotide diversity of 226 sequences of pgk1 gene in Triticeae species was characterized. Phylogenetic analyses based on the pgk1 gene were carried out to determine the diploid origin of polyploids within the tribe in relation to their A(u), B, D, St, Ns, P, and H haplomes. Sequences from the Ns genome represented the highest nucleotide diversity values for both polyploid and diploid species with π=0.03343 and θ=0.03536 for polyploid Ns genome sequences and π=0.03886 and θ=0.03886 for diploid Psathyrostachys sequences, while Triticum urartu represented the lowest diversity among diploid species at π=0.0011 and θ=0.0011. Nucleotide variation of diploid Aegilops speltoides (π=0.2441, presumed the B genome donor of Triticum species) is five times higher than that (π=0.00483) of B genome in polyploid species. Significant negative Tajima's D values for the St, A(u), and D genomes along with high rates of polymorphisms and low sequence diversity were observed. Origins of the A(u), B, and D genomes were linked to T. urartu, A. speltoides, and A. tauschii, respectively. Putative St genome donor was Pseudoroegneria, while Ns and P donors were Psathyrostachys and Agropyron. H genome diploid donor is Hordeum. © 2013 Elsevier B.V. All rights reserved.

  8. Genes and QTLs controlling inflorescence and stem branch architecture in Leymus (Poaceae: Triticeae) Wildrye.

    Science.gov (United States)

    Larson, Steven R; Kellogg, Elizabeth A; Jensen, Kevin B

    2013-01-01

    Grass inflorescence and stem branches show recognizable architectural differences among species. The inflorescence branches of Triticeae cereals and grasses, including wheat, barley, and 400-500 wild species, are usually contracted into a spike formation, with the number of flowering branches (spikelets) per node conserved within species and genera. Perennial Triticeae grasses of genus Leymus are unusual in that the number of spikelets per node varies, inflorescences may have panicle branches, and vegetative stems may form subterranean rhizomes. Leymus cinereus and L. triticoides show discrete differences in inflorescence length, branching architecture, node number, and density; number of spikelets per node and florets per spikelet; culm length and width; and perimeter of rhizomatous spreading. Quantitative trait loci controlling these traits were detected in 2 pseudo-backcross populations derived from the interspecific hybrids using a linkage map with 360 expressed gene sequence markers from Leymus tiller and rhizome branch meristems. Alignments of genes, mutations, and quantitative trait loci controlling similar traits in other grass species were identified using the Brachypodium genome reference sequence. Evidence suggests that loci controlling inflorescence and stem branch architecture in Leymus are conserved among the grasses, are governed by natural selection, and can serve as possible gene targets for improving seed, forage, and grain production.

  9. New Isosomodes (Hymenoptera: Eurytomidae) and implications for biological control in rice (Oryza sativae; Poaceae)

    Science.gov (United States)

    Two new species of Isosomodes Ashmead are described and illustrated: I. monteria from Colombia and I. dorado from Venezuela. Key characters for separation from other species are provided. Rearing data for I. monteria indicate that it is a parasitoid of Conocephalus (Orthoptera: Tettigoniidae) eggs ...

  10. Leaf anatomy of the South African Danthonieae (Poaceae. XVII. The genus Chaetobromus

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1988-12-01

    Full Text Available The leaf anatomy of Chaetobromus Nees is described and illustrated. The genus has non-Kranz anatomy but with a low lateral cell count. The abaxial epidermis is not pooid as microhairs are present, the silica bodies are dumbbell-shaped and the stomatal subsidiaries are dome-shaped. From the sample o f 33 randomly selected speci­mens from throughout the distribution range o f the genus it was possible to identify four anatomical groups, each associated with a specific habitat and differing in vegetative morphology. These intergrade in a reticulate pattern and do not constitute discrete entities. It appears that the genus is monospecific with four poorly separated subspecific taxa.

  11. Complex evolution in Arundinarieae (Poaceae: Bambusoideae): incongruence between plastid and nuclear GBSSI gene phylogenies.

    Science.gov (United States)

    Zhang, Yu-Xiao; Zeng, Chun-Xia; Li, De-Zhu

    2012-06-01

    The monophyly of tribe Arundinarieae (the temperate woody bamboos) has been unequivocally recovered in previous molecular phylogenetic studies. In a recent phylogenetic study, 10 major lineages in Arundinarieae were resolved based on eight non-coding plastid regions, which conflicted significantly with morphological classifications both at the subtribal and generic levels. Nevertheless, relationships among and within the 10 lineages remain unclear. In order to further unravel the evolutionary history of Arundinarieae, we used the nuclear GBSSI gene sequences along with those of eight plastid regions for phylogenetic reconstruction, with an emphasis on Chinese species. The results of the plastid analyses agreed with previous studies, whereas 13 primary clades revealed in the GBSSI phylogeny were better resolved at the generic level than the plastid phylogeny. Our analyses also revealed many inconsistencies between the plastid DNA and the nuclear GBSSI trees. These results implied that the nuclear genome and the plastid genome had different evolutionary trajectories. The patterns of incongruence suggested that lack of informative characters, incomplete lineage sorting, and/or hybridization (introgression) could be the causes. Seven putative hybrid species were hypothesized, four of which are discussed in detail on the basis of topological incongruence, chromosome numbers, morphology, and distribution patterns, and those taxa probably resulted from homoploid hybrid speciation. Overall, our study indicates that the tribe Arundinarieae has undergone a complex evolution. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Panicum simulans (Paniceae, Poaceae, a new species from southern Africa and its leaf anatomy

    Directory of Open Access Journals (Sweden)

    L. Smook

    1993-12-01

    Full Text Available Panicum simulans Smook from northern Namibia is formally described. The morphology and leaf blade anatomy in transection and surface view, as observed under the light microscope, are described. The species is compared to others with which it has been confused in the past.  P. simulans can be readily distinguished from  P. novemnerve Stapf and P schinzii Hack, on the basis of both anatomical and morphological characters such as the venation of the lower glume and the photosynthetic anatomy, which is of the NAD-me subtype of the C4 photosynthetic pathway. On this basis it appears that P simulans is closely allied to the P. coloratum L. group of species and should be placed in section Panicum of subgenus Panicum.

  13. Ultrastructural morphologic description of the wild rice species Oryza latifolia (Poaceae in Costa Rica

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    Ethel Sánchez

    2003-06-01

    Full Text Available The wild rice species Oryza latifolia is endemic to Tropical America, allotetraploid and has a CCDD genome type. It belongs to the officinalis group of the genus Oryza. This species is widely distributed through-out the lowlands of Costa Rica and it is found on different life zones, having great morphologic diversity. The purpose of this research is to perform a morphologic description of O. latifolia samples of three Costa Rican localities (Carara, Liberia and Cañas and to see if the phenotypic diversity of the species is reflected at the ultra-structure level. Structures such as the leaf blade, ligule, auricles and spikelet were analyzed. Leaf blade morphology of the specimens from the three localities is characterized by the presence of diamond-shaped stomata with papillae, zipper-like rows of silica cells; a variety of evenly distributed epicuticular wax papillae and bulky prickle trichomes. The central vein of the leaf blade from the Cañas populations is glabrous, while those from Carara and Liberia have abundant papillae. There are also differences among the borders of the leaf blade between these locations. Cañas and Liberia present alternating large and small prickle trichomes ca. 81 and 150 µm, while Carara exhibits even sized prickle trichomes of ca. 93 µm. Auricles from Cañas are rectangular and present long trichomes along the surface ca. 1.5 mm, while those of Liberia and Carara wrap the culm and exhibit trichomes only in the borders. The ligule from the plants of Carara has an acute distal tip, while that of Cañas and Liberia is blunt. The Liberia spikelet has large lignified spines while Cañas and Carara show flexible trichomes.La especie silvestre Oryza latifolia es endémica de América, tetraploide y de genoma CCDD. Pertenece a las especies del género Oryza del grupo officinalis. Presenta una amplia distribución en las tierras bajas de Costa Rica y se le encuentra en varias zonas de vida, mostrando una gran diversidad morfológica. El propósito de este trabajo fue realizar una descripción ultraestructural de plantas de O. latifolia provenientes de las localidades Carara, Liberia y Cañas con el fin de determinar si hay variación intrapo-blacional. Se analizó la lámina foliar, lígula, aurículas y espiguilla, con énfasis en las estructuras de valor taxonómico. La morfología de la lámina foliar de los especímenes de las tres localidades se caracteriza por la presencia de estomas romboidales con papilas, células de sílice de forma crenada, variedad de papilas de cera, distribuidas en forma regular y tricomas espinosos abultados de ca 53 µm. La vena central de la lámina foliar de O. latifolia, localidad Cañas, es lisa, mientras que en Carara y Liberia presenta papilas. Los bordes de la lámina foliar difieren entre localidades; Cañas y Liberia presentan tricomas ganchudos grandes de ca. 150 µm y pequeños de ca 81 µm que alternan, mientras que Carara tiene tricomas ganchudos pequeños de igual tamaño (ca. 93 µm. Las aurículas de Cañas son rectangulares y presentan tricomas atenuados largos de ca. 1.5mm en toda la superficie, mientras las de Liberia y Carara son envolventes y presentan dichos tricomas solamente en los bordes. La lígula de Carara tiene el extremo distal agudo, mientras que Cañas y Liberia lo tienen truncado. La espiguilla de Liberia presenta tricomas espinosos lignificados grandes, mientras que Cañas y Carara tienen tricomas flexibles.

  14. Ultraestructura del bambú Guadua paniculata (Poaceae: Bambusoideae de Costa Rica

    Directory of Open Access Journals (Sweden)

    Mayra Montiel

    2006-06-01

    Full Text Available Se evaluaron características ultraestructurales de la lámina y la bráctea de la hoja, así como de las ramas, de plantas adultas de Guadua paniculata recolectadas en Costa Rica. Sus características ultraestructurales diagnósticas incluyen el patrón celular de la zona adaxial de la lámina foliar, los largos tricomas unicelulares de la superficie abaxial, los más numerosos tricomas auriculares, agrupados en número de 17, el patrón de cera cuticular y las bandas de estomas rodeadas de papilas céricas.Sections of leaf lamina, leaf sheath and branches of adult Guadua paniculata collected in Costa Rica, were studied ultrastructurally. Diagnostic ultrastructural characteristics include the cellular pattern of the adaxial zone in the leaf blade; the large unicellular trichomes of the abaxial area, the more numerous auricular trichomes, grouped in number of 17, the pattern of cuticular wax and the bands of stomata surrounded by ceric papillae. Rev. Biol. Trop. 54(Suppl. 2: 29-34. Epub 2006 Dec. 01.

  15. MORPHO-ANATOMICAL STUDY OF CRYPSIS SCHOENOIDES (L. LAM. SPECIES OF POACEAE FAMILY

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    C. G. Simeanu

    2003-01-01

    Full Text Available This paper presents data on the morphology and anatomy of vegetative organs. The root is fasciculated and has a primary structure. The stem is ramified at the base, it has also primary structure and the transport vases are disposed on three concentrically circles. The leaf has homogenous mesophyl; the epidermal cells are longitudinally disposed parallel with the leaf nerves and the stomata are of biperigen type.

  16. Leaf anatomy of the South African Danthonieae (Poaceae. XII. Pentameris thuarii

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    R. P. Ellis

    1984-12-01

    Full Text Available The leaf blade anatomy of  Pentameris thuarii Beauv. is described and illustrated. It is shown that the leaf anatomy of  P. thuarii bears little resemblance to the anatomy of  P. macrocatyciiw (Steud. Schweick..  P. obiiisifolia (Hochst. Schweick., P. longiglumis (Nccs Stapf or P. dregeana Stapf. The leaf anatomy of P. thuarii was found to correspond closely with that of some specimens of Pentaschistis pallescens (Schrad. Stapf, P. silvatica Adamson and P. lonuosa (Trin. Stapf. The morphology of these  Pentaschistis specimens needs to be compared with that of  P. thuarii in order to establish whether the true relationships of  P. thuarii lie with these taxa. Anatomically. P. thuarii does not appear to be closelv related to anv species presently classified in Pentameris.

  17. Molecular phylogeny of the arthrostylidioid bamboos (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) and new genus Didymogonyx.

    Science.gov (United States)

    Tyrrell, Christopher D; Santos-Gonçalves, Ana Paula; Londoño, Ximena; Clark, Lynn G

    2012-10-01

    We present the first multi-locus chloroplast phylogeny of Arthrostylidiinae, a subtribe of neotropical woody bamboos. The morphological diversity of Arthrostylidiinae makes its taxonomy difficult and prior molecular analyses of bamboos have lacked breadth of sampling within the subtribe, leaving internal relationships uncertain. We sampled 51 taxa, chosen to span the range of taxonomic diversity and morphology, and analyzed a combined chloroplast DNA dataset with six chloroplast regions: ndhF, trnD-trnT, trnC-rpoB, rps16-trnQ, trnT-trnL, and rpl16. A consensus of maximum parsimony and Bayesian inference analyses reveals monophyly of the Arthrostylidiinae and four moderately supported lineages within it. Six previously recognized genera were monophyletic, three polyphyletic, and two monotypic; Rhipidocladum sect. Didymogonyx is here raised to generic status. When mapped onto our topology, many of the morphological characters show homoplasy. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Systematic study of annual weed Phalaris minor Retz. (Poaceae) in Iran.

    Science.gov (United States)

    Keshavarzi, Maryam; Khaksar, Mahnaz; Seifali, Mahvash

    2007-04-15

    Phalaris minor is an anuual grass in North temperate regions. This weed is inhabited in damp soils and swamps of Irano-Turanian phytogeographic region. Anatomical structure of leaf trans-sections, dorsal epidermis and morphological variation of 23 accessions of Phalaris minor from different parts of Iran were studied. Coastal and inter-coastal characters were evaluated and the intra-specific variations were studied. Results indicate a lot of variations in shape and wall thickness of long cells, the number and type of short cell, stomata number per leaf area, shape of silica bodies, guard cells and the presence of different kind of hairs. Also sclerenchyma position, the shape of midrib and furrows of leaf blade and the features of vascular bundles show a lot of variations. Different accessions show variations in shoot length and spike shape and length. The results indicate that there may be some ecotypes in Phalaris minor of Iran. Statistical analysis is provided for Iranian populations of weedy Phalaris minor.

  19. Morphology and anatomy of the diaspores and seedling ofPaspalum (Poaceae, Poales)

    OpenAIRE

    EICHEMBERG,MAYRA T.; Scatena,Vera L.

    2013-01-01

    RESUMO O conhecimento relativo ao diásporo e ao desenvolvimento pós-seminal de Paspalum L. é importante para a conservação da biodiversidade dos campos, devido sua importância na representatividade e no melhoramento genético de pastagens. A morfologia do diásporo e do desenvolvimento pós-seminal de Paspalum dilatatum Poir. (rizomatosa); P. mandiocanum Trin. var. subaequiglume Barreto (estolonífera), P. pumilum Nees. (cespitosa decumbente) e P. urvillei Steud. (cespitosa ereta) foi descrita pr...

  20. Ultraestructura del bambú Guadua angustifolia var. bicolor (Poaceae: Bambusoideae, presente en Costa Rica

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    Mayra Montiel

    2006-06-01

    Full Text Available Se estudió la ultraestructura anatómica de la lámina y la vaina de la hoja, así como de la bráctea del culmo, de Guadua angustifolia var. bicolor, por medio del microscopio electrónico de barrido. Se encontraron similitudes con otras guaduas: estomas de alto domo, células largas con paredes sinuosas y células de sílice. Son propios de la var. bicolor el patrón estomático en la zona abaxial de la hoja cerca de la vaina, con la presencia de gran cantidad de tricomas ganchudos y sin papilas; las brácteas de color café dorado que cubren los culmos y tienen tricomas papilares que cubren el haz; y el abundante número de tricomas auriculares, en grupos de 12.The anatomy of several parts of Guadua angustifolia var. bicolor was analyzed and characterized under a scanning electron icroscope. any similarities ere observed with other Guadua species, particularly the presence of high dome stomata, of large cells with sinuous walls and of silica cells. Specific bicolor characteristics include (1 a different stomatal pattern in the adaxial zone of the leaf base (close to the sheath; (2 the abundance of hook-sshaped trichomes without papilla; (3 the distinctive golden brown color of the bract that covers the culm (caused by papillar trichomes that cover the adaxial sheath; and (4 the size of the groups of auricular trichomes (formed by 12 trichomes. Rev. Biol. Trop. 54(Suppl. 2: 13-19. Epub 2006 Dec. 01.

  1. Delimiting species boundaries within the Neotropical bamboo Otatea (Poaceae: Bambusoideae) using molecular, morphological and ecological data.

    Science.gov (United States)

    Ruiz-Sanchez, Eduardo; Sosa, Victoria

    2010-02-01

    Species delimitation is a task that has engaged taxonomists for more than two centuries. Recently, it has been demonstrated that molecular data and ecological niche modeling are useful in species delimitation. In this paper multiple data sets (molecular, morphological, ecological) were utilized to set limits for the species belonging to the Neotropical bamboo Otatea, because there is disagreement about species circumscriptions and also because the genus has an interesting distribution, with most of its populations in Mexico and a single disjunct population in Colombia. Molecular and morphological phylogenetic analyses recovered trees with conflicting topologies. Tree-based morphological and character-based analyses recognized the same entities. Ecological niche models and PCA/MANOVAS agreed with the recognition of the same entities that resulted from the morphological analyses. Morphological analyses retrieved clades supported by diagnostic characters and coherent geographical distributions. Based on these results seven entities should be recognized in Otatea, instead of the three previously described species. Copyright (c) 2009. Published by Elsevier Inc.

  2. Variation in sequences containing microsatellite motifs in the perennial biomass and forage grass, Phalaris arundinacea (Poaceae).

    Science.gov (United States)

    Barth, Susanne; Jankowska, Marta Jolanta; Hodkinson, Trevor Roland; Vellani, Tia; Klaas, Manfred

    2016-03-22

    Forty three microsatellite markers were developed for further genetic characterisation of a forage and biomass grass crop, for which genomic resources are currently scarce. The microsatellite markers were developed from a normalized EST-SSR library. All of the 43 markers gave a clear banding pattern on 3% Metaphor agarose gels. Eight selected SSR markers were tested in detail for polymorphism across eleven DNA samples of large geographic distribution across Europe. The new set of 43 SSR markers will help future research to characterise the genetic structure and diversity of Phalaris arundinacea, with a potential to further understand its invasive character in North American wetlands, as well as aid in breeding work for desired biomass and forage traits. P. arundinacea is particularly valued in the northern latitude as a crop with high biomass potential, even more so on marginal lands.

  3. Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus/sinensis complex (Poaceae).

    Science.gov (United States)

    Huang, Chao-Li; Ho, Chuan-Wen; Chiang, Yu-Chung; Shigemoto, Yasumasa; Hsu, Tsai-Wen; Hwang, Chi-Chuan; Ge, Xue-Jun; Chen, Charles; Wu, Tai-Han; Chou, Chang-Hung; Huang, Hao-Jen; Gojobori, Takashi; Osada, Naoki; Chiang, Tzen-Yuh

    2014-12-01

    Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59 million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M = 3.36 × 10(-9) to 1.20 × 10(-6) , resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M. sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.

  4. Surface properties correlate to the digestibility of hydrothermally pretreated lignocellulosic Poaceae biomass feedstocks

    DEFF Research Database (Denmark)

    Tristan Djajadi, Demi; Hansen, Aleksander R.; Jensen, Anders

    2017-01-01

    in response to hydrothermal pretreatment at different severities are still not sufficiently understood. Results: Potentially important lignocellulosic feedstocks for biorefining, corn stover (Zea mays subsp. mays L.), stalks of Miscanthus × giganteus, and wheat straw (Triticum aestivum L.) were systematically...... lignocellulosic biomass and may help design new approaches to overcome biomass recalcitrance....

  5. Meiotic behavior in apomictic Brachiaria ruziziensis × B. brizantha (Poaceae progenies

    Directory of Open Access Journals (Sweden)

    Veridiana Aparecida Fuzinatto

    2012-12-01

    Full Text Available Hybrids combining desirable traits from divergent parents are the main objective of some Brachiaria (Syn. Urochloa P. Beauv. breeding programs. There is great interest in the development of apomictic hybrid cultivars that combine desirable genes such as resistance to spittlebugs, high nutritive value, and tolerance to acid soils. Microsporogenesis of six apomictic progenies resulting from a tetraploid (2n = 4x = 36 cross between B. ruziziensis × B. brizantha was evaluated under light microscopy. Genetic recombination, ensured by multivalent chromosome association and crossing-over at prophase occurred in low frequency among progenies, and in one, recombination was almost nonexistent. The percentage of meiocytes with meiotic abnormalities among progenies ranged from 16.6 % to 85.6 %. Besides an observed irregular chromosome segregation typical of polyploid hybrids in these five progenies, putative meiotic mutations characterized as desynapsis and divergent spindle organization occurred in three progenies. These anomalies caused frequent fractionation of the genome into several microspores of different sizes. In Brachiaria, new cultivars must be apomictic to fix the genotype. However, Brachiaria is a pseudogamous apomict, and viable gametes are necessary to produce viable seeds. Considering meiotic behavior, only two progenies are promising for advancement in the breeding program.

  6. DNA elimination in embryogenic development of Pennisetum glaucum x Pennisetum purpureum (Poaceae) hybrids.

    Science.gov (United States)

    Nunes, J D; Azevedo, A L S; Pereira, A V; Paula, C M P; Campos, J M S; Lédo, F J S; Santos, V B

    2013-10-22

    Interspecific hybridization between Napier grass (Pennisetum purpureum), which is widely grown in Brazil for cattle forage, and pearl millet (Pennisetum glaucum) has been used as a breeding strategy for the development of improved cultivars. However, the hybrid between these two species is sterile due to its triploid condition (2n = 3x = 21 chromosomes), which hinders its use in crop breeding programs. It is known that genomic alterations result from the hybridization process. In order to measure the loss of DNA during embryo development, we used flow cytometry to estimate the nuclear DNA content of triploid and tetraploid embryos produced by interspecific hybridization between Napier grass and pearl millet. The triploid and tetraploid hybrids had a mean DNA content of 4.99-4.87 and 5.25-4.84 pg, at 10 and 30 days after pollination, respectively. The mean reduction in DNA content was higher in the tetraploid hybrids. The flow cytometry results revealed progressive genomic instability in these triploid and tetraploid hybrids, with this instability causing significant alterations in the DNA content of the hybrids.

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

    Directory of Open Access Journals (Sweden)

    Hai-Fei Zhou

    2013-01-01

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

  8. Early colonization pattern of maize (Zea mays L. Poales, Poaceae roots by Herbaspirillum seropedicae (Burkholderiales, Oxalobacteraceae

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    Rose A. Monteiro

    2008-12-01

    Full Text Available The bacterium Herbaspirillum seropedicae is an endophytic diazotroph found in several plants, including economically important poaceous species. However, the mechanisms involved in the interaction between H. seropedicae and these plants are not completely characterized. We investigated the attachment of Herbaspirillum to maize roots and the invasion of the roots by this bacterium using H. seropedicae strain SMR1 transformed with the suicide plasmid pUTKandsRed, which carries a mini-Tn5 transposon containing the gene for the Discosoma red fluorescent protein (Dsred constitutively expressed together with the kanamycin resistance gene. Integration of the mini-Tn5 into the bacterial chromosome yielded the mutant H. seropedicae strain RAM4 which was capable of expressing Dsred and could be observed on and inside fresh maize root samples. Confocal microscopy of maize roots inoculated with H. seropedicae three days after germination showed that H. seropedicae cell were attached to the root surface 30 min after inoculation, were visible in the internal tissues after twenty-four hours and in the endodermis, the central cylinder and xylem after three days.

  9. Global change effects on Bromus tectorum L. (Poaceae) at its high-elevation range margin

    Science.gov (United States)

    Concilio, Amy L.; Loik, Michael E.; Belnap, Jayne

    2013-01-01

    Global change is likely to affect invasive species distribution, especially at range margins. In the eastern Sierra Nevada, California, USA, the invasive annual grass, Bromus tectorum, is patchily distributed and its impacts have been minimal compared with other areas of the Intermountain West. We used a series of in situ field manipulations to determine how B. tectorum might respond to changing climatic conditions and increased nitrogen deposition at the high-elevation edge of its invaded range. Over 3 years, we used snow fences to simulate changes in snowpack, irrigation to simulate increased frequency and magnitude of springtime precipitation, and added nitrogen (N) at three levels (0, 5, and 10 g m-2) to natural patches of B. tectorum growing under the two dominant shrubs, Artemisia tridentata and Purshia tridentata, and in intershrub spaces (INTR). We found that B. tectorum seedling density in April was lower following deeper snowpack possibly due to delayed emergence, yet there was no change in spikelet production or biomass accumulation at the time of harvest. Additional spring rain events increased B. tectorum biomass and spikelet production in INTR plots only. Plants were primarily limited by water in 2009, but colimited by N and water in 2011, possibly due to differences in antecedent moisture conditions at the time of treatments. The threshold at which N had an effect varied with magnitude of water additions. Frequency of rain events was more influential than magnitude in driving B. tectorum growth and fecundity responses. Our results suggest that predicted shifts from snow to rain could facilitate expansion of B. tectorum at high elevation depending on timing of rain events and level of N deposition. We found evidence for P-limitation at this site and an increase in P-availability with N additions, suggesting that stoichiometric relationships may also influence B. tectorum spread.

  10. Karyotype characterization and comparison of three hexaploid species of Bromus Linnaeus, 1753 (Poaceae)

    Science.gov (United States)

    Artico, Leonardo Luís; Mazzocato, Ana Cristina; Ferreira, Juliano Lino; Carvalho, Carlos Roberto; Clarindo, Wellington Ronildo

    2017-01-01

    Abstract Chromosome morphometry and nuclear DNA content are useful data for cytotaxonomy and to understand the evolutionary history of different taxa. For the genus Bromus Linnaeus, 1753, distinct ploidy levels have been reported, occurring from diploid to duodecaploid species. The geographic distribution of Bromus species has been correlated with chromosome number and ploidy level. In this study, the aims were to determine the nuclear genome size and characterize the karyotype of the South American Bromus species: Bromus auleticus Trinius ex Nees, 1829, Bromus brachyanthera Döll, 1878 and Bromus catharticus Vahl, 1791. The mean nuclear 2C value ranged from 2C = 12.64 pg for B. catharticus to 2C = 17.92 pg for B. auleticus, meaning a maximum variation of 2C = 5.28 pg, equivalent to 41.70%. Despite this significant difference in 2C value, the three species exhibit the same chromosome number, 2n = 6x = 42, which confirms their hexaploid origin. Corroborating the genome size, the chromosome morphometry (total, short- and long-arm length) and, consequently, the class differed among the karyotypes of the species. Based on the first karyograms for these Bromus species, some morphologically similar and several distinct chromosome pairs were found. Therefore, the karyotype characterization confirmed the hexaploid origin of the studied Bromus species, which differ in relation to the karyogram and the nuclear 2C value. Considering this, cytogenetics and flow cytometry can be used to discriminate Bromus species, contributing to taxonomy and systematic studies and providing information on the evolutionary history of this taxa. PMID:28919960

  11. Genetic variation in native and introduced populations of Taeniatherum caput-medusae (Poaceae)

    Science.gov (United States)

    Genetic analysis of both native and introduced populations of invasive species can be used to examine population origins and spread. Accurate delineation of an invasive species’ source populations can contribute to the search for specific and effective biological control agents. Medusahead, Taenia...

  12. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1991-12-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9.B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  13. Phylogenetic analysis of Bambusa (Poaceae: Bambusoideae) based on internal transcribed spacer sequences of nuclear ribosomal DNA.

    Science.gov (United States)

    Sun, Ye; Xia, Nianhe; Lin, Rushun

    2005-12-01

    Phylogenetic analyses of Bambusa species were performed using internal transcribed spacer sequences of nuclear ribosomal DNA. The 21 species sampled included members of Bambusa (sensu stricto), Dendrocalamopsis, Dendrocalamus, Guadua, Leleba, and Lingnania. Arundinaria gigantea was used as an outgroup. Using the maximum parsimony method with PAUP*, gaps were treated as missing states or new states. Parsimonious analysis revealed that Dendrocalamus latiflorus was closely related to the members of Dendrocalamopsis. Dendrocalamus membranaceus was a sister species to Dendrocalamus strictus. Three Dendrocalamus species were closely related to and nested in a polyphyletic Bambusa. Bambusa subaequalis was a sister species to B. multiplex, B. emeiensis to B. chungii, B. contracta to B. hainanensis, and B. flexuosa was a sister species to B. sinospinosa, B. tuldoides, B. surrecta, B. intermedia, and B. valida group, which raised doubts about the monophyly of the subgenera Bambusa (sensu stricto), Dendrocalamopsis, Leleba, and Lingnania under the genus Bambusa.

  14. The evaluation of adaptation of Eragrostis minor Host. (Poaceae coenopopulations to the conditions of transformed environment

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    Nataliia A. Pashkevych

    2015-05-01

    Full Text Available Structural and functional features of E. minor, using morphometric traits and phytomass fractions of model coenopopulations are studied to determine adaptive capacity of species in different environments transformed the environment of forest, forest-steppe and steppe zones. Depending on edaphic conditions plants and organs of plants may increase several times in size and weight. The index of morphological integration of model coenopopulations indicates the uniformity of vegetative and generative organs of plants at different environmental conditions. In various conditions significant value to coenopopulations differentiation contribute signs of individual length as well as length and number of generative organs. Formation of the maximum number of spikelets (feature with the highest contribute to dispersion of data corresponds to extreme edaphic conditions of growth combined with a high degree of recreation. However, decreasing environmental transformation is accompanied by double fulfillment of breeding potential of E. minor coenopopulations, while setting density of individuals reduce in almost 5-15 times. Thus, E. minor has mixed competitive Stress-tolerant Ruderal type as adaptation to condition of secondary areal.

  15. Phylogeny of a genomically diverse group of elymus (poaceae allopolyploids reveals multiple levels of reticulation.

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    Roberta J Mason-Gamer

    Full Text Available The grass tribe Triticeae (=Hordeeae comprises only about 300 species, but it is well known for the economically important crop plants wheat, barley, and rye. The group is also recognized as a fascinating example of evolutionary complexity, with a history shaped by numerous events of auto- and allopolyploidy and apparent introgression involving diploids and polyploids. The genus Elymus comprises a heterogeneous collection of allopolyploid genome combinations, all of which include at least one set of homoeologs, designated St, derived from Pseudoroegneria. The current analysis includes a geographically and genomically diverse collection of 21 tetraploid Elymus species, and a single hexaploid species. Diploid and polyploid relationships were estimated using four molecular data sets, including one that combines two regions of the chloroplast genome, and three from unlinked nuclear genes: phosphoenolpyruvate carboxylase, β-amylase, and granule-bound starch synthase I. Four gene trees were generated using maximum likelihood, and the phylogenetic placement of the polyploid sequences reveals extensive reticulation beyond allopolyploidy alone. The trees were interpreted with reference to numerous phenomena known to complicate allopolyploid phylogenies, and introgression was identified as a major factor in their history. The work illustrates the interpretation of complicated phylogenetic results through the sequential consideration of numerous possible explanations, and the results highlight the value of careful inspection of multiple independent molecular phylogenetic estimates, with particular focus on the differences among them.

  16. Phylogeny of a genomically diverse group of elymus (poaceae) allopolyploids reveals multiple levels of reticulation.

    Science.gov (United States)

    Mason-Gamer, Roberta J

    2013-01-01

    The grass tribe Triticeae (=Hordeeae) comprises only about 300 species, but it is well known for the economically important crop plants wheat, barley, and rye. The group is also recognized as a fascinating example of evolutionary complexity, with a history shaped by numerous events of auto- and allopolyploidy and apparent introgression involving diploids and polyploids. The genus Elymus comprises a heterogeneous collection of allopolyploid genome combinations, all of which include at least one set of homoeologs, designated St, derived from Pseudoroegneria. The current analysis includes a geographically and genomically diverse collection of 21 tetraploid Elymus species, and a single hexaploid species. Diploid and polyploid relationships were estimated using four molecular data sets, including one that combines two regions of the chloroplast genome, and three from unlinked nuclear genes: phosphoenolpyruvate carboxylase, β-amylase, and granule-bound starch synthase I. Four gene trees were generated using maximum likelihood, and the phylogenetic placement of the polyploid sequences reveals extensive reticulation beyond allopolyploidy alone. The trees were interpreted with reference to numerous phenomena known to complicate allopolyploid phylogenies, and introgression was identified as a major factor in their history. The work illustrates the interpretation of complicated phylogenetic results through the sequential consideration of numerous possible explanations, and the results highlight the value of careful inspection of multiple independent molecular phylogenetic estimates, with particular focus on the differences among them.

  17. Leaf anatomy of the South African Danthonieae (Poaceae. XV. The genus Elytrophorus

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    R. P. Ellis

    1986-12-01

    Full Text Available The leaf anatomy of  Elytrophorus globularis Hack, and  E. spicatus (Willd. A. Camus is described and illustrated from freshly fixed material from SWA/Namibia and Botswana. It is shown that these two species are anatomically indistinguishable. It is suggested that they are conspecific. and that  E. spicatus possibly represents juvenile plants with immature inflorescences. The anatomical evidence strongly refutes a chloridoid relationship for Elytrophorus but appears to support arundinoid affinities for the genus. Striking anatomical and ecological similarities exist between  Elytrophorus and  Sacciolepis huillensis (Rendle Stapf. No significant leaf anatomical differences separate  Elytrophorus from S.  huillensis and some of the other C3 panicoid taxa and. consequently,  Elytro­phorus may represent a link between the Arundinoideae and the Panicoideae.

  18. Studies upon morhological and biological traits of Festuca rubra, subsp.fallax (Poaceae

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    Bogusław Sawicki

    2013-12-01

    Full Text Available Observation and measurements of some traits of Festuca rubra L., subsp. fallax (Thuill. Hack. ecotypes were made in 1995-1997 using samples selected from natural habitats and collected in Grassland Experimental Station in Sosnowica. High differentiation of traits under study and their correlations were found. Valorized ecotypes are good material for new varieties breeding.

  19. Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus / sinensis complex (Poaceae)

    KAUST Repository

    Huang, Chao-Li

    2014-11-11

    Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M=3.36x10(-9) to 1.20x10(-6), resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M.sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.

  20. Effect of some adjuvants application on enhancing sulfosulfuron herbicide performance on Phalaris minor- Poaceae

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    Mohammad Mehdizadeh

    2015-02-01

    Full Text Available Nowadays environmental pollution by pesticides application is a major concern for health. Efficiency of many herbicides can be increased by adding adjuvants to the spray solution. Therefore greenhouse study was conducted during 2014 to determine the efficacy of three adjuvants (Citogate, Castor oil and Canola oil at concentrations of 0.1 and 0.2 (%v/v with 5, 10, 20, 30 and 40 g a.i\\ha of sulfosulfuron herbicide on littleseed canary grass. Results showed that the adjuvants enhanced the efficacy of sulfosulfuron in decreasing the dry weights of littleseed canary grass. Performance of herbicide was increased with enhancing its concentrations. Measured ED50 and ED90 concentrations of sulfosulfuron in control were 16.74 and 32.22 g a.i\\ha, respectively. Whereas the values for Citogate 0.2 (%v\\v, was 5.86 and 13.34 g a.i\\ha, respectively. The addition of Citogate and Castor oil had the highest and lowest effect on sulfosulfuron efficacy against Littleseed canary grass. In conclusion, the study revealed that Citogate concentrations had powerful effects on herbicide efficacy followed by Canola oil.

  1. Distribution of native legumes (Leguminoseae) in frequently burned longleaf pine (Pinaceae)-wiregrass (Poaceae) ecosystems.

    Science.gov (United States)

    Hainds, M J; Mitchell, R J; Palik, B J; Boring, L R; Gjerstad, D H

    1999-11-01

    Legume species distribution and abundance and selected environmental variables were quantified across a complex gradient (varying in both water-holding capacity and fertility) for frequently burned longleaf pine (Pinus palustris)-wiregrass (Aristida stricta) ecosystems. Legumes were present in all months; however, abundance peaked in June and was minimal after killing frosts in October. Legume species were prominent in the flora (43 species encountered) ubiquitous (94% of 2-m(2) subplots had at least one legume species), and abundant (nearly 120 000 stems/ha). Although most species were widely distributed throughout the gradient, Lespedeza angustifolia was distinctly associated with the more hydric end of the gradient, while both Petalostemon pinnatum and Galactia microphylla were located in the more xeric extreme. The percentage variation in species that could be accounted for by environmental variation was low (27%). Of the variation that could be accounted for, a number of environmental variables were important, including soil moisture, pine basal area (i.e., light), and bivalent base cations (e.g., Ca(2+)). Although gradients in resource availability among sites did not affect the distribution of species or abundance of legumes strongly, variation in resources are likely to regulate N(2)-fixation rates of the various native legume species, and thereby affect ecological functions such as maintenance of N capital and productivity.

  2. género Digitaria (Poaceae, Panicoideae, Paniceae en Colombia y Venezuela

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    Andrea S. Vega

    2005-01-01

    Full Text Available Digitaria cuatrecasasii, nueva especie de Honduras, Panamá, Colombia y Venezuela, se describe e ilustra. Se discute la posición taxonómica de D. cuatrecasasii y se propone su inclusión en la sección Leianthae. Se provee una tabla comparativa con las especies de la sección y observaciones referidas a la especie más relacionada. Digitaria californica var. villosissima, D. corynotricha, D. curvinervis, D. fragilis y D. sacchariflora son citadas por primera vez en Colombia. Digitaria aequiglumis var. aequiglumis, D. argillacea var. nulliseta, D. ciliaris var. rhachiseta, D. costaricensis, D. eriantha, D. filiformis var. laeviglumis, D. lehmanniana var. dasyantha, D. parva, D. sacchariflora y D. ternata se mencionan por primera vez en Venezuela. Digitaria cardenasiana y D. villiculmis constituyen nuevos sinónimos de D. corynotricha; D. aequatorienis se subordina a D. pittieri. Se adicionan nuevas citas en los siguientes países: D. argillacea var. argillacea en Perú, D. argillacea var. nulliseta en Guatemala, D. curvinervis en Ecuador y México, D. eriantha en Ecuador, D. fragilis en Nicaragua y Panamá, D. lehmanniana var. lehmanniana en Cuba y D. leucites en México. El trabajo incluye sinonimia, iconografía, distribución geográfica y ecología, nombres vernáculos y exsiccata. Se provee también una clave para la identificación de los taxones. Once especies son ilustradas por primera vez.

  3. Las especies del género festuca (poaceae en Colombia

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    Daniel Stancík

    2003-01-01

    Full Text Available Se presenta el primer estudio taxonómico del género Festuca para Colombia, el cual se encuentra representado por 31 especies nativas y 2 especies introducidas. Se describen 12 especies y 1 subespecie nuevas para la ciencia (F. boyacensis, F. chita, F. chitagana, F. cocuyana, F. hatico, F. monguensis, F. nereidaensis, F. pilar-franceii, F. sumapana, F. toca, F. venezuelana y F. woodii. Se incluyen descripciones e ilustraciones de todas las especies, aportándose datos sobre su ecología y distribución geográfica y una clave para facilitar la determinación de todas las especies de Festuca en Colombia

  4. The Kranz syndrome in the Eragrostideae (Chloridoideae, Poaceae as indicated by carbon isotopic ratios*

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    Hector O. Panarello

    1984-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 13C/12C ratios are generally regarded as being very reliable indicators of C3 or C4 photosynthesis. These relative carbon isotope ratios are expressed as a negative δ 3C and fall into two distinct groups: Kranz (or C4 plants with δ between -9°/00 no and -18°/00 and non-Kranz (C3 plants with δ between -22°/00 and -280/00 no. In this paper, 29 taxa, representing 12 genera, of the tribe Eragrostideae were examined by mass spectrometry for their δ 13C in dried leaf tissue. All these taxa proved to be C4, plants with δ13C values ranging between -13,6°/oo and -10.9°/oo. These findings confirmed published leaf anatomical observations which showed that all the studied taxa had characteristic Kranz leaf anatomy. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:12.0pt; mso-para-margin-right:0cm; mso-para-margin-bottom:12.0pt; mso-para-margin-left:0cm; text-align:justify; line-height:12.0pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

  5. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

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    J. J. Spies

    1991-12-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9.B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  6. Merging Fargesia dracocephala into Fargesia decurvata (Bambusoideae, Poaceae: implications from morphological and ITS sequence analyses.

    Directory of Open Access Journals (Sweden)

    Yu-Qu Zhang

    Full Text Available AIMS: Fargesia decurvata is closely allied with F. dracocephala and differs in 5 major characters (i.e. the culm sheath blade base shape, the width of the culm sheath blade base, the auricle shape, and the lower surface of leaf blade in Fargesia. It is difficult to distinguish these two species because of existing of transitional statements of characters. The aims of this paper are to (i investigate whether the variation of the characters is continuous or not; (ii reveal whether the publishment of F. dracocephala was the result of discontinuous sampling of F. decurvata or not. METHODS: Ten populations of F. decurvata and F. dracocephala were investigated in their entire distribution (including type localities. The statements of 5 major characters were measured from 693 annual and 693 perennial culms of 231 individuals in 10 populations, and analyzed at population, individual and culm levels. UPGMA cluster analysis was carried out based on 29 characters from 10 populations of F. decurvata and F. dracocephala and 2 populations of F. qinlingensis as outgroup. The ITS sequences were also sequenced and analyzed. IMPORTANT FINDINGS: Five major characters exhibited great variation not only at population level, but at individual level within a population, even the culm level within an individual and in different parts of the same culm. Cluster analyses showed that 10 populations of F. decurvata and F. dracocephala were not divided into two species, but they were well separated with outgroup. There was no difference in floral organ between F. decurvata and F. dracocephala. MP and NJ trees based on ITS sequences showed the same results with the cluster analysis on morphological characters. All the facts indicated that the publishment of F. dracocephala was the result of discontinuous sampling of F. decurvata, and F. dracocephala should be treated as the synonym of F. decurvata.

  7. Evidence of programmed cell death during microsporogenesis in an interspecific Brachiaria (Poaceae: Panicoideae: Paniceae) hybrid.

    Science.gov (United States)

    Fuzinatto, V A; Pagliarini, M S; Valle, C B

    2007-05-11

    Morphological changes have been investigated during plant programmed cell death (PCD) in the last few years due to the new interest in a possible apoptotic-like phenomenon existing in plants. Although PCD has been reported in several tissues and specialized cells in plants, there have been few reports of its occurrence during microsporogenesis. The present study reports a typical process of PCD during meiosis in an interspecific Brachiaria hybrid leading to male sterility. In this hybrid, some inflorescences initiated meiosis but it was arrested in zygotene/pachytene. From this stage, meiocytes underwent a severe alteration in shape showing substantial membrane blebbing; the cytoplasm became denser at the periphery; the cell nucleus entered a progressive stage of chromatin disintegration, and then the nucleolus disintegrated, and the cytoplasm condensed and shrunk. The oldest flowers of the raceme showed only the callose wall in the anthers showing obvious signs of complete sterility.

  8. Preliminary DNA fingerprinting of the turf grass Cynodon dactylon (Poaceae: Chloridoideae

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    R. Roodt

    2002-12-01

    Full Text Available Identification of different cultivars of turf grasses is often very difficult. In a preliminary attempt to identify different cultivars o f Cynodon dactylon (L. Pers.. random amplified polymorphic DNA (RAPD analyses of some well-known cultivars used in South Africa, i.e. Bayview. Cape Royal, Florida. Hamsmith. Silverton Blue. Skaapplaas and Titdwart. as well as 10 potential new cultivars, were done. These results were used to determine the genetic distances among cultivars. Only five primers w ere needed to obtain a specific fragment pattern for each cultivar. The degree o f amplification w as used as an additional criterion by including all visible fragments, excluding very faint fragments and only including the brightest fragments. The neighbour-joining trees o f C.  dactylon showed best resolution from the data set w ith all visible fragments included. although fragment intensity did not affect the tree topology. The cultivars Silverton Blue and Bayview exhibited the greatest genetic variation and two potential new cultivars were identified. RAPD analyses can. therefore, be used to distin­guish between different C. dactylon cultivars and to determine the genetic variation between them by calculating genetic distances.

  9. Characterization of the Arthropod Community Associated with Switchgrass (Poales: Poaceae) in Nebraska

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is a perennial warm-season grass, native to the North American Great Plains. Recently, this prairie grass has received increased attention as a potential biomass energy crop. Little is known about the arthropod community affecting switchgrass grown under either mana...

  10. Leaf anatomy of the South African Danthonieae (Poaceae. XV. The genus Elytrophorus

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1986-12-01

    Full Text Available The leaf anatomy of  Elytrophorus globularis Hack, and  E. spicatus (Willd. A. Camus is described and illustrated from freshly fixed material from SWA/Namibia and Botswana. It is shown that these two species are anatomically indistinguishable. It is suggested that they are conspecific. and that  E. spicatus possibly represents juvenile plants with immature inflorescences. The anatomical evidence strongly refutes a chloridoid relationship for Elytrophorus but appears to support arundinoid affinities for the genus. Striking anatomical and ecological similarities exist between  Elytrophorus and  Sacciolepis huillensis (Rendle Stapf. No significant leaf anatomical differences separate  Elytrophorus from S.  huillensis and some of the other C3 panicoid taxa and. consequently,  Elytro­phorus may represent a link between the Arundinoideae and the Panicoideae.

  11. Taxonomy and leaf anatomy of the genus Ehrharta (Poaceae in southern Africa: the Ramosa group

    Directory of Open Access Journals (Sweden)

    G. E. Gibbs Russel

    1989-12-01

    Full Text Available The Ramosa species group in the genus Ehrharta is distinguished morphologically by small spikelets with sterile lemmas similar to each other, with tips rounded, truncate or mucronate, with sides glabrous, scabrous or shortly hairy, and with bases appendaged and usually bearded. The rectangular intercostal long cells with sinuous walls, the dome-shaped stomata with a raised rim surrounding the pore aperture, the absence of epicuticular wax and the microhairs without a tapering distal cell are diagnostic anatomically. The Ramosa group is composed of two species: E. ramosa (Thunb. Swartz subsp.  ramosa, subsp.  aphylla (Schrad. Gibbs Russell and  E. rehmannii Stapf subsp.  rehmannii; subsp. filiformis (Nees Gibbs Russell; subsp.  subspicata (Stapf Gibbs Russell. All taxa are linked by intermediates to one or two others in the group. The closest relationship of the Ramosa group is to the Calyeina species group, on the basis of both morphological and anatomical characters.

  12. A phylogenetic analysis of the monogenomic Triticeae (Poaceae) based on morphology

    DEFF Research Database (Denmark)

    Seberg, Ole; Frederiksen, Signe Elisabeth

    2001-01-01

    not traditionally included in Aegilops s.J. Most of the 33 characters used in the analysis are coded as binary. The only four multistate characters in the matrix are treated as unordered. Three diploid species of Bromus are used as outgroup. The number of equally parsimonious trees found is very large (approx....... 170000; length = 107, ci = 0.36, ri = 0.75) and the strict consensus tree has an expectedly low level of resolution. However, most of the equally parsimonious trees owe their existence to an unresolved Aegilops clade. If this clade is replaced by its hypothetical ancestor, the number of equally...

  13. 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.

  14. Chromosome numbers and meiotic analysis in the pre-breeding of Brachiaria decumbens (Poaceae).

    Science.gov (United States)

    Ricci, Gléia Cristina Laverde; De Souza-Kaneshima, Alice Maria; Felismino, Mariana Ferrari; Mendes-Bonato, Andrea Beatriz; Pagliarini, Maria Suely; Do Valle, Cacilda Borges

    2011-08-01

    A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented 2n = 18; 27 accessions, 2n = 36; and 2 accessions, 2n = 45 chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.

  15. Introduction history and population genetics of the invasive grass Bromus tectorum (Poaceae) in Canada.

    Science.gov (United States)

    Valliant, Morgan T; Mack, Richard N; Novak, Stephen J

    2007-07-01

    The invasive annual Bromus tectorum (cheatgrass) is distributed in Canada primarily south of 52° N latitude in two diffuse ranges separated by the extensive coniferous forest in western Ontario. The grass was likely introduced independently to eastern and western Canada post-1880. We detected regional variation in the grass's genetic diversity using starch gel electrophoresis to analyze genetic diversity at 25 allozyme loci in 60 populations collected across Canada. The Pgm-1a & Pgm-2a multilocus genotype, which occurs in the grass's native range in Eastern Europe, is prevalent in eastern Canada but occurs at low frequency in western Canada. In contrast, the Got-4c multilocus genotype, found in the native range in Central Europe, is widespread in populations from western Canada. Overall genetic diversity of B. tectorum is much higher in eastern Canada than in the eastern U.S., while the genetic diversity in populations in western North America is similar between Canada and the U.S. The distribution of genetic diversity across Canada strongly suggests multiple introduction events. Heterozygous individuals, which are exceedingly rare in B. tectorum, were detected in three Canadian populations. Formation of novel genotypes through occasional outcrossing events could spark adaptive evolution and further range expansion across Canada of this exceedingly damaging grass.

  16. Mechanisms of Oryza sativa (Poaceae resistance to Tagosodes orizicolus (Homoptera: Delphacidae under greenhouse condition in Venezuela

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    Alex González

    2012-03-01

    Full Text Available Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the “Rice hoja blanca virus”. During 2006-2007 we carried out research under greenhouse conditions at Fundación Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundación Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition. Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control ‘Bluebonnet 50’ was consistently susceptible across experiments and the resistant control ‘Makalioka’ had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and viposition. The genotype ‘FD0241-M-17-6-1-1-1-1’ was identified with possible tolerance to the direct damage of sogata.Tagosodes orizicolus es una de las principales plagas del cultivo del arroz en América tropical causando dos tipos de daños a la planta, el directo, por efecto de la alimentación y oviposición; el indirecto, por la transmisión del virus de la hoja blanca del arroz. Durante el período 2006-2007 se llevó a cabo una investigación bajo condiciones de umbráculo en la Fundación Danac, Venezuela, con el objeto de determinar los mecanismos de resistencia de antixenosis, antibiosis y tolerancia a T. orizicolus que pudieran estar actuando en líneas avanzadas y cultivares del programa de mejoramiento enético de arroz de las instituciones INIA y Fundación Danac. Para la evaluación de antixenosis se utilizó el método de libre elección, para antibiosis (efecto sobre sobrevivencia y oviposición de los insectos el de alimentación forzada, adicionalmente se usó un método indirecto para estimar la tolerancia. Dentro de los principales parámetros determinados se encontraban: grado de daño, número de insectos posados sobre plantas de arroz, porcentaje de mortalidad de sogata en estado adulto, número de huevos y se calculó un índice de tolerancia con base en la biomasa. Los resultados mostraron que los genotipos de arroz evaluados poseen diferentes combinaciones en cuanto a los mecanismos de resistencia, así como el grado de su efecto. El testigo ‘Bluebonnet 50’ se mantuvo consistentemente susceptible en las evaluaciones y el testigo resistente ‘Makalioka’ fue el único genotipo que presentó alta antixenosis y alta antibiosis para sobrevivencia y oviposición. El resto de los genotipos presentaron un menor o mayor grado de resistencia de tipo antixenosis y antibiosis para sobrevivencia y oviposición. Se identificó el genotipo ‘FD0241-M-17-6-1-1-1-1’ con posible tolerancia al daño directo de sogata.

  17. Meristem identity and phyllotaxis in inflorescence development

    Directory of Open Access Journals (Sweden)

    Madelaine Elisabeth Bartlett

    2014-10-01

    Full Text Available Inflorescence morphology is incredibly diverse. This diversity of form has been a fruitful source of inquiry for plant morphologists for more than a century. Work in the grasses (Poaceae, the tomato family (Solanaceae, and Arabidopsis (Brassicaceae has led to a richer understanding of the molecular genetics underlying this diversity. The character of individual meristems, a combination of the number (determinacy and nature (identity of the products a meristem produces, is key in the development of plant form. A framework that describes inflorescence development in terms of shifting meristem identities has emerged and garnered empirical support in a number of model systems. We discuss this framework and highlight one important aspect of meristem identity that is often considered in isolation, phyllotaxis. Phyllotaxis refers to the arrangement of lateral organs around a central axis. The development and evolution of phyllotaxis in the inflorescence remains underexplored, but recent work analyzing early inflorescence development in the grasses identified an evolutionary shift in primary branch phyllotaxis in the Pooideae. We discuss the evidence for an intimate connection between meristem identity and phyllotaxis in both the inflorescence and vegetative shoot, and touch on what is known about the establishment of phyllotactic patterns in the meristem. Localized auxin maxima are instrumental in determining the position of lateral primordia. Upstream factors that regulate the position of these maxima remain unclear, and how phyllotactic patterns change over the course of a plant’s lifetime and evolutionary time, is largely unknown. A more complete understanding of the molecular underpinnings of phyllotaxis and architectural diversity in inflorescences will require capitalizing on the extensive resources available in existing genetic systems, and developing new model systems that more fully represent the diversity of plant morphology.

  18. Meristem identity and phyllotaxis in inflorescence development.

    Science.gov (United States)

    Bartlett, Madelaine E; Thompson, Beth

    2014-01-01

    Inflorescence morphology is incredibly diverse. This diversity of form has been a fruitful source of inquiry for plant morphologists for more than a century. Work in the grasses (Poaceae), the tomato family (Solanaceae), and Arabidopsis thaliana (Brassicaceae) has led to a richer understanding of the molecular genetics underlying this diversity. The character of individual meristems, a combination of the number (determinacy) and nature (identity) of the products a meristem produces, is key in the development of plant form. A framework that describes inflorescence development in terms of shifting meristem identities has emerged and garnered empirical support in a number of model systems. We discuss this framework and highlight one important aspect of meristem identity that is often considered in isolation, phyllotaxis. Phyllotaxis refers to the arrangement of lateral organs around a central axis. The development and evolution of phyllotaxis in the inflorescence remains underexplored, but recent work analyzing early inflorescence development in the grasses identified an evolutionary shift in primary branch phyllotaxis in the Pooideae. We discuss the evidence for an intimate connection between meristem identity and phyllotaxis in both the inflorescence and vegetative shoot, and touch on what is known about the establishment of phyllotactic patterns in the meristem. Localized auxin maxima are instrumental in determining the position of lateral primordia. Upstream factors that regulate the position of these maxima remain unclear, and how phyllotactic patterns change over the course of a plant's lifetime and evolutionary time, is largely unknown. A more complete understanding of the molecular underpinnings of phyllotaxis and architectural diversity in inflorescences will require capitalizing on the extensive resources available in existing genetic systems, and developing new model systems that more fully represent the diversity of plant morphology.

  19. Anther ontogeny in Brachypodium distachyon.

    Science.gov (United States)

    Sharma, Akanksha; Singh, Mohan B; Bhalla, Prem L

    2015-03-01

    Brachypodium distachyon has emerged as a model plant for the improvement of grain crops such as wheat, barley and oats and for understanding basic biological processes to facilitate the development of grasses as superior energy crops. Brachypodium is also the first species of the grass subfamily Pooideae with a sequenced genome. For obtaining a better understanding of the mechanisms controlling male gametophyte development in B. distachyon, here we report the cellular changes during the stages of anther development, with special reference to the development of the anther wall. Brachypodium anthers are tetrasporangiate and follow the typical monocotyledonous-type anther wall formation pattern. Anther differentiation starts with the appearance of archesporial cells, which divide to generate primary parietal and primary sporogenous cells. The primary parietal cells form two secondary parietal layers. Later, the outer secondary parietal layer directly develops into the endothecium and the inner secondary parietal layer forms an outer middle layer and inner tapetum by periclinal division. The anther wall comprises an epidermis, endothecium, middle layer and the secretory-type tapetum. Major documented events of anther development include the degradation of a secretory-type tapetum and middle layer during the course of development and the rapid formation of U-shaped endothecial thickenings in the mature pollen grain stage. The tapetum undergoes degeneration at the tetrad stage and disintegrates completely at the bicellular stage of pollen development. The distribution of insoluble polysaccharides in the anther layers and connective tissue through progressive developmental stages suggests their role in the development of male gametophytes. Until sporogenous cell stage, the amount of insoluble polysaccharides in the anther wall was negligible. However, abundant levels of insoluble polysaccharides were observed during microspore mother cell and tetrad stages and gradually

  20. Phylogenetic analysis of Tilletia and allied genera in order Tilletiales (Ustilaginomycetes; Exobasidiomycetidae) based on large subunit nuclear rDNA sequences.

    Science.gov (United States)

    Castlebury, Lisa A; Carris, Lori M; Vinky, Kálmán

    2005-01-01

    The order Tilletiales (Ustilaginomycetes, Basidiomycota) includes six genera (Conidiosporomyces, Erratomyces, Ingoldiomyces, Neovossia, Oberwinkleria and Tilletia) and approximately 150 species. All members of Tilletiales infect hosts in the grass family Poaceae with the exception of Erratomyces spp., which occur on hosts in the Fabaceae. Morphological features including teliospore ornamentation, number and nuclear condition of primary basidiospores and ability of primary basidiospores to conjugate and form an infective dikaryon were studied in conjunction with sequence analysis of the large subunit nuclear rDNA gene (nLSU). Analysis based on nLSU data shows that taxa infecting hosts in the grass subfamily Pooideae form one well supported lineage. This lineage comprises most of the reticulate-spored species that germinate to form a small number of rapidly conjugating basidiospores and includes the type species Tilletia tritici. Two tuberculate-spored species with a large number of nonconjugating basidiospores, T. indica and T. walkeri, and Ingoldiomyces hyalosporus are also included in this lineage. Most of the species included in the analysis with echinulate, verrucose or tuberculate teliospores that germinate to form a large number (>30) of nonconjugating basidiospores infect hosts in the subfamilies Panicoideae, Chloridoideae, Arundinoideae and Ehrhartoideae. This group of species is more diverse than the pooid-infecting taxa and in general do not form well supported clades corresponding to host subfamily. The results of this work suggest that morphological characters used to segregate Neovossia, Conidiosporomyces and Ingoldiomyces from Tilletia are not useful generic level characters and that all included species can be accommodated in the genus Tilletia.

  1. Meristem identity and phyllotaxis in inflorescence development

    Science.gov (United States)

    Bartlett, Madelaine E.; Thompson, Beth

    2014-01-01

    Inflorescence morphology is incredibly diverse. This diversity of form has been a fruitful source of inquiry for plant morphologists for more than a century. Work in the grasses (Poaceae), the tomato family (Solanaceae), and Arabidopsis thaliana (Brassicaceae) has led to a richer understanding of the molecular genetics underlying this diversity. The character of individual meristems, a combination of the number (determinacy) and nature (identity) of the products a meristem produces, is key in the development of plant form. A framework that describes inflorescence development in terms of shifting meristem identities has emerged and garnered empirical support in a number of model systems. We discuss this framework and highlight one important aspect of meristem identity that is often considered in isolation, phyllotaxis. Phyllotaxis refers to the arrangement of lateral organs around a central axis. The development and evolution of phyllotaxis in the inflorescence remains underexplored, but recent work analyzing early inflorescence development in the grasses identified an evolutionary shift in primary branch phyllotaxis in the Pooideae. We discuss the evidence for an intimate connection between meristem identity and phyllotaxis in both the inflorescence and vegetative shoot, and touch on what is known about the establishment of phyllotactic patterns in the meristem. Localized auxin maxima are instrumental in determining the position of lateral primordia. Upstream factors that regulate the position of these maxima remain unclear, and how phyllotactic patterns change over the course of a plant's lifetime and evolutionary time, is largely unknown. A more complete understanding of the molecular underpinnings of phyllotaxis and architectural diversity in inflorescences will require capitalizing on the extensive resources available in existing genetic systems, and developing new model systems that more fully represent the diversity of plant morphology. PMID:25352850

  2. Siliceous microfossils as late Quaternary paleo-environmental indicators at Braamhoek wetland, South Africa

    Science.gov (United States)

    Finné, M.; Norström, E.; Risberg, J.; Scott, L.

    2009-04-01

    A core from a peat-sequence covering the last 16 ka (16,000 calibrated years before present) from the Braamhoek wetland, eastern South Africa, produced siliceous microfossils, SiO2, (phytoliths and diatoms). Phytoliths are minute silica particles precipitated within or between plant cells and can be found among many plant families. They are, however, particularly common in the Grass family (Poaceae). The peat core was rich in phytoliths, while diatoms were less prominent, probably due to degradation during wetland plant growth associated with silica uptake. The Braamhoek wetland is located in the grassland biome of southern Africa and the vast majority of the phytoliths found in the Braamhoek wetland are interpreted as being derived from grasses growing in and around the wetland. Phytolith analysis presents a possibility to extract more detailed information regarding grass sub-family/species distribution than other methods to date and can thus be used to gain new insights to ecological and climatological changes in grass dominated environments. Of the twelve Poaceae sub-families, eight are present in South Africa. We focussed on phytolith morphology and paleo-environmental applications of especially three of them, viz. Pooideae (C3), Panicoideae (mainly C4) and Chloridoideae (C4). These sub-families create rather distinct morphological phytoliths and all have different climatic preferences. The high abundance of grasses from the Arundinoideae (C3) sub-family in the Braamhoek wetland, however, called for a new approach to phytolith methodology in our study. Further, a small-scale phytolith study of modern soil samples yielded additional information of how to interpret fossil assemblages in terms of moisture availability. With this study we present the first continuous phytolith and diatom record from South Africa for the late Pleistocene and Holocene. The phytolith assemblages indicate a clear dominance of C3-grasses within the wetland throughout the sequence. Two

  3. Alterações espirométricas em doenças obstrutivas: afinal, o quanto é relevante? Spirometric changes in obstructive disease: after all, how much is significant?

    Directory of Open Access Journals (Sweden)

    André Luis Pinto Soares

    2013-02-01

    Full Text Available OBJETIVO: Estabelecer os limites superiores para mudanças em VEF1, capacidade vital lenta (CVL, CVF e capacidade inspiratória (CI após o uso de placebo em pacientes com obstrução ao fluxo aéreo. MÉTODOS: Cento e dois adultos com obstrução ao fluxo aéreo (VEF1 = 62 ± 19% do previsto foram incluídos neste estudo. Todos os participantes realizaram manobras de CVL e CVF antes e depois do uso de spray de placebo. As mudanças em VEF1, CVL, CVF e CI foram expressas em valores absolutos, porcentagem de variação em relação aos valores basais e porcentagem dos valores previstos, e foram calculados os IC95% e os percentis 95. A análise fatorial foi realizada a fim de determinar como essas alterações se agrupavam. RESULTADOS: Considerando os IC95% e percentis 95 e após o arredondamento dos valores, obtivemos os seguintes limites superiores para resposta significante: VEF1 = 0,20 L, CVF = 0,20 L, CVL = 0,25 L e CI = 0,30 L (em valores absolutos; VEF1 = 12%, CVF = 7%, CVL = 10% e CI = 15% (em porcentagem de variação em relação aos valores basais e VEF1 = 7%, CVF = 6%, CVL = 7% e CI = 12% (em porcentagem dos valores previstos. CONCLUSÕES: Em pacientes com obstrução ao fluxo aéreo, a CI apresenta maior variabilidade do que a CVF e a CVL. Para a CI, valores maiores que 0,30 L e 15% de variação em relação ao valor basal devem ser considerados significantes. Para CVF, valores maiores que 0,20L e 7% de variação em relação ao valor basal são significantes. Alternativamente, alterações de mais de 0,20 L e 7% do previsto no VEF1 e na CVF devem ser consideradas significantes. Na análise fatorial, os parâmetros espirométricos se agruparam em três dimensões, expressando mudanças no fluxo, volume e hiperinsuflação dinâmica.OBJECTIVE: To establish the upper limits for changes in FEV1, slow vital capacity (SVC, FVC, and inspiratory capacity (IC after placebo administration in patients with airflow obstruction. METHODS: One hundred and two adults with airflow obstruction (FEV1 = 62 ± 19% of predicted were included in the study. All of the participants performed SVC and FVC maneuvers before and after the administration of placebo spray. The changes in FEV1, SVC, FVC, and IC were expressed as absolute values, percentage of change from baseline values, and percentage of predicted values, 95% CIs and 95th percentiles being calculated. Factor analysis was performed in order to determine how those changes clustered. RESULTS: Considering the 95% CIs and 95th percentiles and after rounding the values, we found that the upper limits for a significant response were as follows: FEV1 = 0.20 L, FVC = 0.20 L, SVC = 0.25 L, and IC = 0.30 L (expressed as absolute values; FEV1 = 12%, FVC = 7%, SVC = 10%, and IC = 15% (expressed as percentage of change from baseline values; and FEV1 = 7%, FVC = 6%, SVC = 7%, and IC = 12% (expressed as percentage of predicted values. CONCLUSIONS: In patients with airflow obstruction, IC varies more widely than do FVC and SVC. For IC, values greater than 0.30 L and 15% of change from the baseline value can be considered significant. For FVC, values greater than 0.20 L and 7% of change from the baseline value are significant. Alternatively, changes exceeding 0.20 L and 7% of the predicted value can be considered significant for FEV1 and FVC. On factor analysis, spirometric parameters clustered into three dimensions, expressing changes in flows, volumes, and dynamic hyperinflation.

  4. Afinal, Desenvolvimento Regional serve para quê? Reflexões a partir da sociologia da libertação de Fals Borda e da sociologia da exploração de Casanova

    Directory of Open Access Journals (Sweden)

    Luciana Butzke

    2016-09-01

    Full Text Available A história, tanto do desenvolvimento quanto da teoria social na América Latina, está imersa no paradigma eurocêntrico, no encobrimento do Outro (maiorias exploradas no subcontinente, na exploração da natureza e na predominância de discursos “desde fora”. A teoria do desenvolvimento regional, considerada de médio alcance, é derivada da teoria do desenvolvimento e traz, em sua bagagem, enfoques importados que prometem milagres ao levar o progresso às regiões subdesenvolvidas da periferia. A teoria social, no geral, e a sociologia-centro, em particular, são parte desse paradigma e desse discurso. Nesse sentido, trazemos neste artigo a sociologia-periferia, de Fals Borda e de Casanova, em diálogo com a questão regional, como possibilidade de contra-discurso. Essa sociologia abriga a crítica eurocêntrica da teoria social e do desenvolvimento que teve lugar na América Latina, e discute o compromisso da ciência no pensar com a região e no agir para transformar/libertar a região.

  5. Tracking Performance Requirements for Tracking Performance Requirements for Rotorcraft Instrument Approaches to Reduced Minima. Phase 1. Preliminary Study (Exigences Relatives Aux Performances De Suivi D’Approche Aux Instruments D’Un Giravion Afin De Reduire Les)

    Science.gov (United States)

    1991-02-01

    A l’a~ronautique jug~es importantes, completes et durables en termes de contribution aux connaissances actuelles. CAHIERS D’AERONAUTIQUE (AN...83 large overshoot of pad (50 + feet); late in power application 84 past pad by 10 feet; large flare 85 stopped short - taxied to pad 86 50-75 foot

  6. Afinal, quais Variáveis Caracterizam a Existência de Cluster Arranjos Produtivos Locais (APLs e dos Sistemas Locais de Produção e Inovação (SLPIs?

    Directory of Open Access Journals (Sweden)

    Rafael Mendes Lübeck

    2012-06-01

    Full Text Available Nesse artigo, foi estabelecida uma diferenciação entre os termos mais utilizados para caracterizar as aglomerações de empresas. É possível identificar na literatura a utilização dos termos Cluster, Arranjo Produtivo Local (APL e Sistemas Locais de Produção e Inovação (SLPIs como similares, no entanto, tais nomenclaturas referem-se a diferentes estágios de desenvolvimento das aglomerações territoriais de empresas, ressaltando, inclusive, que a simples aglomeração de empresas de uma mesma cadeia produtiva em uma determinada região não necessariamente caracteriza um APL ou SLPI. O objetivo desse artigo foi demonstrar a necessidade de conjugar métodos e variáveis para traçar um quadro mais preciso da situação produtiva territorial, permitindo a classificação dos aglomerados de empresas em acordo estágio de desenvolvimento. Observou-se, como fator preponderante, a força da cooperação entre os atores locais como formadora de uma vantagem competitiva que impõe aos interesses exógenos o aproveitamento das potencialidades endógenas desenvolvidas e estrategicamente cultivadas em aglomerações em estágios mais desenvolvidos.DOI:10.5585/riae.v11i1.1745

  7. « Inverser la plaisanterie afin de secouer le joug » ou comment vicier un stéréotype “Change the Joke and Slip the Yoke” or How to Twist a Stereotype

    Directory of Open Access Journals (Sweden)

    Jacqueline Berben

    2009-07-01

    Full Text Available A California professor, a painter, an author and an occasional rancher Percival Everett appears as an iconoclast who often undermines racial and political stereotypes, ethnocentric and cultural narratives while provoking the academic establishment by making fun of its various literary theories. An excellent example is the short story, “The Appropriation of Cultures,” in the collection Damned If IDo (2004. The tale is a not-so-subtle deconstruction/reconstruction of symbols deeply embedded in the culture of the American South and its ultra-conservative values. Everett endows his protagonist with his favorite tools – irony, humor, artifice – by turning the Confederate flag into a Black Power symbol and laying African American claim to the Southern anthem, “Dixie”. Thus the archetypal “trickster” figure triumphs over his bigger, stronger adversary by getting him to psychologically relinquish treasured icons of Southern white superiority and by playing on that very myth. This article shows that post-structuralism per se might be inherently linked to African Americans.

  8. Sur la reconnaissance de la compétence exclusive des groupements religieux afin d‘instaurer leur structure intrinsèque et les normes intérieures des relations en tant qu’une des garanties ...

    Directory of Open Access Journals (Sweden)

    Philip Ryabykh

    2012-11-01

    Full Text Available Version étendue de la déclaration de l'Eglise orthodoxe russe, en tant que tierce partie dans l’affaire «Syndicat “Le Bon Pasteur” c. Roumanie» (requête 2330/09, envoyée à la Grande Chambre de la Cour européenne des droits de l'hommeSOMMAIRE: 1. Brève histoire de l’affaire – 2. Préambule – 3. Protection de la compétence exclusive des groupements religieux en vue d’instaurer leur structure intrinsèque et les normes intérieures des relations au point de vue de la législation de la Roumanie – 4. Application du principe de l’autonomie des groupements religieux et du principe de l’inadmissibilité d’intervenir pour l’État aux affaires intérieures des groupements religieux – 5. Non-contradiction de la Convention des exigences intérieures des groupements religieux sur la loyauté et la conformité des personnes se trouvant dans les relations de service avec le groupement religieux – 6. Absence des raisons fournies par les faits juridiques suffisantes et justifiant réellement l’assimilation (la mise au même niveau des groupements religieux avec n’importe quelles autres organisations-employeurs dans la sphère de la réglementation des relations de travail – 7. Légalité de l’instauration des restrictions à la création et les activités des syndicats dans les certaines sphères des relations publiques – 8. Compétence de la Roumanie de fixer dans la législation les restrictions à la liberté des syndicats conformément à la sphère des relations religieuses – 9. Signification des résultats du jugement de l’affaire «Syndicat “Le Bon Pasteur” c. Roumanie» (requête 2330/09 pour L’Église Orthodoxe Russe- 10. Conclusion.

  9. AVALIAÇÃO DA DIVERSIDADE GENÉTICA ATRAVÉS DE RAPD DE ACESSOS DE MANIÇOBA (Manihot pseudoglaziovii PAX & HOFFM. E DE DUAS ESPÉCIES AFINS DE INTERESSE FORRAGEIRO

    Directory of Open Access Journals (Sweden)

    Fabiana Augusta Santiago Beltrão

    2007-01-01

    Full Text Available With the objective to analyze the genetc variability in natural populations, 14 accesses of Manihot had been studied pseudglaziovii, collected in the state of the Paraíba, in the microregion Curimataú Paraibano, beyond an access of M. esculenta Cranz (cassava and a natural hybrid between these two species. Five plants of each access had been multiplied through statue and after that cultivated in an experimental area in standardized conditions, to have a homogeneous exteriorizacion of each genotype. The otimizaçãocion of the protocol of extraction of the DNA of some accesses of maniçoba and of two similar species of forager interest and to verify the genetic variability through the amplification with molecular markers RAPD saw PCR. Two methods of extraction of the DNA had been tested. The extraction protocol using detergent CTAB made possible to get clean products, less viscous and oxidized. In the analysis of genetic variability they had been used in a total of 10 starters (primers, and only 3 had produced bands, starter OPD2, OPD3 and OPD8 presented greater percentage of polymorphism followed of the OPD2, with values of 30,7% and 42,8%, respectively. These primers can discriminate molecular differences between the accesses of maniçoba and two similar species.

  10. RSR13 e modificação alostérica da afinidade hemoglobina-oxigênio: abuso entre atletas RSR13 and allosteric change in the hemoglobin-oxygen afinity: abuse among athletes

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    Antonio Claudio Lucas da Nóbrega

    2002-02-01

    Full Text Available O ácido metilpropiônico (RSR13 é um modificador alostérico da hemoglobina, com a qual se liga de forma não-covalente, diminuindo sua afinidade pelo oxigênio de modo dose-dependente e, conseqüentemente, aumentando a oxigenação periférica. O objetivo deste artigo é apresentar brevemente as evidências científicas acerca das características farmacológicas e funcionais, indicações médicas e efeitos adversos do uso do RSR13 por atletas, a mais recente alternativa de aumento artificial do desempenho. Estudos experimentais preliminares verificaram algum efeito positivo do RSR13 sobre a recuperação do miocárdio isquêmico e sobre a extensão da isquemia cerebral, mas as principais indicações estudadas atualmente são a cirurgia com hipotermia e cardioplegia durante circulação extracorpórea e o uso como agente coadjuvante potenciador da radioterapia para certos tumores sólidos. Somente um estudo em modelo canino mostrou aumento do consumo máximo de oxigênio em músculo isolado, não existindo evidências de que o RSR13 possa efetivamente melhorar o desempenho em humanos. Em realidade, já foram descritos efeitos adversos, como diminuição da perfusão sanguínea, elevação da pressão arterial e diminuição da função renal. Antecipando o potencial aumento da utilização do RSR13 por atletas, métodos já foram desenvolvidos para sua detecção em amostras de urina humana.Methylpropionic acid (RSR13 is an allosteric hemoglobin modifier to which it binds in a non-covalent manner, reducing its affinity to oxygen in a dose-dependent fashion, and consequently, increasing peripheral oxygenation. The purpose of this article is to briefly present scientific evidence concerning pharmacological and functional characteristics, medical indications, and adverse effects of RSR13 use by athletes, the most recent alternative to enhance performance artificially. Preliminary experimental studies have verified some positive effect of RSR13 on the recovery of ischemic myocardium and on the extension of cerebral ischemia. However, the main indications currently under study are surgery with hypothermia and cardioplegia during extra-corporeal circulation and the use as a radiotherapy enhancing agent for certain solid tumors. One single study with a canine model has shown increased maximal oxygen consumption in isolated muscles, there existing no evidence that RSR13 can effectively enhance performance in humans. Actually, adverse effects such as reduced blood perfusion, increased arterial blood pressure, and impaired renal function have been described. As an anticipation of the potential increased use of RSR13 by athletes, methods have been developed for its detection in human urine samples.

  11. The academisation of technical education at the end of the Ancien Régime La academización de la educación técnica afines del Antiguo Régimen

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    Agustín ESCOLANO BENITO

    2013-09-01

    Full Text Available This study examines the genesis of academised technical education at the end of the Ancien Régime. The institutionalisation of the training of professionals of navigation, industry, commerce and agriculture emerged in the second half of the XVIII century in close relation to the programs of economic promotion, of diffusion of science and modern techniques and the pedagogical impulse of the Enlightenment. This process of academisation of the new knowledge would lead to the excision of the workshop- school and the revision of the teaching of the guilds, giving rise to a new model of education of the young, in contrast to the philological paradigm which had been predominant since the Renaissance in secondary schools. This new model was characterised by curricular planning according to the propositions of empirical science, mathematics and useful knowledge, by the discourse of the practicality of knowledge and by the new ethos of the middle class.Este trabajo examina la génesis de la educación técnica academizada a finales del Antiguo Régimen. La institucionalización de la formación de los profesionales de la navegación, la industria, el comercio y la agricultura emerge en la segunda mitad del siglo XVIII en estrecha relación con los programas de fomento económico, de difusión de la ciencia y de la técnica modernas y del impulso pedagógico de la Ilustración. Este proceso de academización de los nuevos saberes desencadena la escisión escuela-taller y la revisión de la enseñanza gremial, dando origen a un nuevo modelo de educación de la juventud, contrapuesto al paradigma filológico dominante desde el Renacimiento en las escuelas secundarias y caracterizado por una ordenación curricular conformada a los presupuestos de la ciencia empírica, la matemática y los conocimientos útiles, por el discurso de la practicidad del saber y por el nuevo ethos de la burguesía.

  12. Estratégias utilizadas por aprendizes de línguas afins: a troca de código Strategies employed by learners of related languages: code-switching

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    Roberta Ferroni

    2012-12-01

    Full Text Available Neste artigo analisamos a troca de código, uma estratégia de compensação que consiste na utilização de uma palavra ou frase em L1, L3 ou L4, no interior do enunciado em L2, empregada por aprendizes de italiano LE cuja língua materna é o português brasileiro, durante a realização em dupla de uma tarefa escrita. A pesquisa, que se baseou nos instrumentos propostos pela etnografia, mostra que a troca de código constitui um potencial para o desenvolvimento da interlíngua e para a aquisição/aprendizagem de LE e que tal estratégia, além de compensar eventuais lacunas linguísticas originadas pela falta de recursos adequados para expressar-se em LE, é usada pelos falantes como procedimento típico da conversação bilíngue para facilitar a comunicação.In this paper we examine code-switching, an achievement strategy consisting in the use of a word or phrase from L1, L3 or L4 within an utterance in L2, as employed by learners of Italian as a foreign language who have Brazilian Portuguese as their mother tongue, while performing a written task in pairs. The research, based on tools provided by an ethnographic approach, shows that code-switching constitutes a potential for developing interlanguage and for the acquisition/learning of a foreign language and that such strategy, in addition to compensating eventual linguistic gaps originated by a lack of proper resources for expression in L2, is used by speakers as a typical procedure in bilingual conversation, in order to facilitate the communication.

  13. Metodología del trabajo de tesis. Con especial aplicación a maestrías en ciencias de la administración y disciplinas afines, 2da. edición por Luisa Mayoral

    OpenAIRE

    2006-01-01

    La doctora Luisa Mayoral ha volcado en este libro el fruto de su experiencia como directora, orientadora y evaluadora de tesis. Su propósito es contribuir a que los alumnos mejoren su entendimiento del proceso que se concreta en los trabajos finales de posgrado: "encontrar un tema, definir los objetivos, delimitar el marco teórico, establecer las variables, derivar indicadores, realizar entrevistas, redactar el trabajo, citar, ...todos aprendizajes que pueden anticiparse para poder disfrutar ...

  14. Mise en place d'un pyromètre afin d'étudier le comportement d'un échantillon soumis à un poinçonnage dynamique

    OpenAIRE

    Del-Lero Moreau, Maher

    2010-01-01

    La découpe adiabatique prend chaque jour plus d’importance grâce à ses nombreux avantages. Mais il reste encore pas mal de paramètres à étudier avant son implantation définitive. Le paramètre étudié est la température atteinte par l’éprouvette lors de la découpe à grande vitesse ; pour cela on va mettre en place un système pyrométrique capable de mesurer cette température. Ce système présente plusieurs parties à étudier : le système optique pour la transmission du rayonnement, le capteur et l...

  15. Support to Industry Partners in Achieving Designation/Certification for the US Safety Act (Soutien aux Partenaires de L’industrie afin de les Aider a Obtenir la Designation/Certification Associee a la Loi Americaine sur la Securite)

    Science.gov (United States)

    2011-10-01

    américain en 2001, le gouvernement américain a pris conscience qu’il devait améliorer sa stratégie visant à prévenir ou à neutraliser les futures...époque, le gouvernement américain s’est aperçu qu’il était nécessaire de faire appel aux nouvelles technologies pour atteindre les objectifs de sa...l’industrie et les investissements en développement technologique, le gouvernement américain a également passé la loi sur le soutien à

  16. Minería de datos como herramienta para el desarrollo de estrategias de mercadeo B2B en sectores productivos, afines a los colombianos: una revisión de casos

    OpenAIRE

    2013-01-01

    Actualmente se estima que el suministro de datos del mundo se duplica cada 20 meses (Berndt y Clifford, 1996). Lo anterior implica un crecimiento excesivo en el volumen de datos que se maneja tanto en la comunidad científica como en los sectores productivos de la economía, que ha sobrepasado la capacidad humana de analizar, resumir y extraer conocimientos a tales cantidades de datos. Lo anterior, hace necesaria una nueva generación de herramientas capaces de automatizar el análisis de los dat...

  17. Gestión integral de residuos sólidos generados en hospitales y centros afines : Comparación microbiológica entre residuos sanitarios y residuos sólidos urbanos

    OpenAIRE

    Mery Letelier, Francisco Santiago

    1998-01-01

    La tesis doctoral aborda temáticamente la gestión integral de los residuos sanitarios, y la caracterización de residuos generados en distintos tipos de centros sanitarios (hospital, clínicas, laboratorios clínicos y clínica veterinaria), así como de residuos sólidos urbanos, a través de su composición, parámetros físicos como la humedad y la densidad, así como de indicadores microbiológicos, culminando en una propuesta de reglamentación aplicable a la gestión de residuos sanitarios....

  18. O que é lixo afinal? Como pensam mulheres residentes na periferia de um grande centro urbano What is garbage, anyway? The opinions of women from an outlying neighborhood in a large Brazilian city

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    Rita de Cássia Franco Rêgo

    2002-12-01

    Full Text Available O lixo urbano constitui-se hoje uma preocupação ambiental nos grandes centros urbanos e ainda pouco se conhece sobre os efeitos à saúde causados pela disposição do mesmo a céu aberto, coleta inadequada e as práticas sanitárias da população em relação a estes resíduos. Como etapa inicial de um estudo epidemiológico que buscou a relação entre exposição ao lixo e diarréia em crianças, desenvolveu-se este estudo com o objetivo de conhecer como mulheres, residentes na periferia de um grande centro urbano, definem lixo, bem como as mesmas percebem a relação entre lixo e doença e entre lixo e outros aspectos ambientais. Em 1999, realizaram-se entrevistas com treze mulheres, em um bairro da periferia de Salvador, utilizando-se um roteiro semi-estruturado. Para a análise das entrevistas utilizou-se o aplicativo "diaricamp" do programa FileMaker. As entrevistadas definem o lixo como tudo que não serve para ser utilizado e o consideram como um problema quando este se encontra acumulado no ambiente, sendo capaz de provocar incômodos como mau cheiro ou poluição visual;quando serve como foco da presença de animais; provoca doenças em crianças e adultos, ou quando o poder para a solução do problema se desloca da esfera individual para o âmbito coletivo ou institucional.Domestic solid waste is cause for current environmental concern in large cities around the world. Little is known about the human health consequences of solid waste disposal in open-air dumps. In addition, there are few studies on people's health practices in relation to solid waste. As the initial step in epidemiological research on the relationship between solid waste and diarrhea, this study describes women's perception of the definition of garbage and the popular understanding of the relationships between garbage and disease, and between garbage and the environment. The study used a qualitative approach in a slum neighborhood in Salvador, Bahia. A total of 13 women were interviewed using a semi-structured questionnaire in 1999. The FileMaker "diaricamp" application was used for data analysis. Interviewees defined garbage as anything useless and considered it a problem whenever it accumulated in the surroundings producing a bad smell or visual pollution, attracted animals, caused disease in children or adults, or was shifted from the individual to the collective/institutional sphere of action to solve the problem.

  19. El recurso a la justicia como vía de resolución de la conflictividad criminal gallega afines del Antiguo Régimen. El ejemplo de Santiago de Compostela (1700-1834

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    Raquel IGLESIAS ESTEPA

    2009-12-01

    Full Text Available RESUMEN: En el Antiguo Régimen, a pesar de los innumerables esfuerzos de la Corona, los tribunales no fueron el único lugar en donde resolver los conflictos de índole criminal y de hecho las sociedades preindustriales se mostraron reticentes a utilizarlos por considerarlos deshonrosos. Este estudio pone de manifiesto el avance en el uso de las instituciones de justicia gallegas durante el siglo XVIII, el cual, lejos de estar determinado por un aumento de la población, se vincula estrechamente con el curso de la vida económica de la Galicia atlántica. El análisis se completa con el examen de las pautas de utilización de los tribunales atendiendo al origen geográfico y al estatus socioprofesional de los demandantes así como a la materia del delito denunciado.ABSTRACT: In the Old Regime, despite the endless efforts of the Crown, tribunals were not the only places where to solve criminal disputes and in fact, pre-industrial societies would show reticence to use them as they would find them dishonourable. This study reveals the progress in the use of the Galician judicial institutions in the 18th century. This progress, far from being determined by an increase of the population, is closely linked with the course of the economic life of the Atlantic Galicia. The analysis is added up with the exam of the guidelines of use of the tribunals according to the geographic origin and the socioprofessional status of the plaintiffs and to the matter of the reported offence.

  20. Minería de datos como herramienta para el desarrollo de estrategias de mercadeo B2B en sectores productivos, afines a los colombianos: una revisión de casos

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    Laura Altamiranda Echeverri

    2013-12-01

    Full Text Available Actualmente se estima que el suministro de datos del mundo se duplica cada 20 meses (Berndt y Clifford, 1996. Lo anterior implica un crecimiento excesivo en el volumen de datos que se maneja tanto en la comunidad científica como en los sectores productivos de la economía, que ha sobrepasado la capacidad humana de analizar, resumir y extraer conocimientos a tales cantidades de datos. Lo anterior, hace necesaria una nueva generación de herramientas capaces de automatizar el análisis de los datos almacenados. El conjunto de estas herramientas lo estudia un nuevo campo de investigación llamado minería de datos (Fayyad et al., 1996. La minería de datos se ha convertido en una herramienta estratégica para la toma de decisiones de mercadeo, producción, organización y demás factores en la empresa, que de cierta manera la hacen más competitiva. El presente artículo analiza la manera como la minería de datos, una técnica ampliamente relacionada con la investigación de operaciones, incide en el diseño de estrategias de mercadeo B2B, en empresas de sectores industriales. Esta investigación guarda relación directa con proyectos investigativos realizados por la Universidad Autónoma del Caribe, y relacionados con el desarrollo de la competitividad e innovación de los sectores estratégicos del departamento del Atlántico.

  1. Medición de la producción científica en América Latina y el Caribe en el campo agrícola y afines: un estudio bibliométrico

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    Saavedra Fernández, Óscar

    2002-06-01

    Full Text Available Twenty-two science and technology indicators from twenty countries, compiled by RICyT were used in an exploratory data analysis about the performance of the countries of the region in the field of Agriculture. Caribbean countries exhibit better performance compared with the rest. Results suggest the idea of widening the scope of such analysis for a larger time span.

    Veintidós indicadores de ciencia y tecnología producidos por la RICyT, correspondientes a veinte países de América Latina y el Caribe son empleados para realizar un análisis exploratorio de datos sobre el desempeño de los países de la región en Ciencias Agrícolas. Se identificaron los países de la cuenca del Caribe con mejor desempeño que los restantes. Los resultados sugieren la idea de extender este tipo de análisis a otras especialidades abarcando una mayor cantidad de años.

  2. Minería de datos como herramienta para el desarrollo de estrategias de mercadeo B2B en sectores productivos, afines a los colombianos: una revisión de casos

    Directory of Open Access Journals (Sweden)

    Laura Altamiranda Echeverri

    2013-12-01

    Full Text Available Actualmente se estima que el suministro de datos del mundo se duplica cada 20 meses (Berndt y Clifford, 1996. Lo anterior implica un crecimiento excesivo en el volumen de datos que se maneja tanto en la comunidad científica como en los sectores productivos de la economía, que ha sobrepasado la capacidad humana de analizar, resumir y extraer conocimientos a tales cantidades de datos. Lo anterior, hace necesaria una nueva generación de herramientas capaces de automatizar el análisis de los datos almacenados. El conjunto de estas herramientas lo estudia un nuevo campo de investigación llamado minería de datos (Fayyad et al., 1996. La minería de datos se ha convertido en una herramienta estratégica para la toma de decisiones de mercadeo, producción, organización y demás factores en la empresa, que de cierta manera la hacen más competitiva. El presente artículo analiza la manera como la minería de datos, una técnica ampliamente relacionada con la investigación de operaciones, incide en el diseño de estrategias de mercadeo B2B, en empresas de sectores industriales. Esta investigación guarda relación directa con proyectos investigativos realizados por la Universidad Autónoma del Caribe, y relacionados con el desarrollo de la competitividad e innovación de los sectores estratégicos del departamento del Atlántico.

  3. Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae in the Brazilian Amazon Bacterias diazotróficas aisladas de arroz silvestre Oryza glumaepatula (Poaceae en la Amazonia brasileña

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    Paulo Ivan Fernandes Júnior

    2013-06-01

    Full Text Available The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg’s medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH+ bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fifty- one bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360bp nifH gene fragment. Among the 38 nifH+ isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus. The growth- promoting ability was confirmed for at least five isolates. For these bacteria, the root and shoot growing results showed higher increases when compared to those observed in plants inoculated with the evaluated reference strains. These results indicate that O. glumaepatula is colonized by a high diverse diazotrophic community in the Brazilian Amazon. Further investigations are now being carried out to determine the taxonomic positions of these isolates and their growth promoting mechanisms.La asociación de gramíneas silvestres con bacterias diazotróficas en los biomas brasileños es poco conocida. El aislamiento y caracterización de las bacterias asociadas con gramíneas silvestres puede contribuir a entender la ecología de las diazotróficas y bacterias con aplicaciones biotecnológicas. En este estudio, caracterizamos aislamientos bacterianos de diazotróficas de Oryza glumaepatula recolectadas en Cerrado y zonas boscosas de la Amazonía en el estado de Roraima, Brasil. Plantas sanas de O. glumepatula fueron recolectadas en cinco zonas boscosas y siete en Cerrado. Las plantas de Cerrado fueron recolectadas en septiembre 2008, mientras que las del bosque en Junio 2008 y Abril 2009. Las plantas y el suelo adherido a las raíces se transfirieron a macetas y se cultivaron durante 35 días en condiciones de invernadero. Durante la cosecha, los brotes y las raíces se trituraron por separado en una solución salina, la suspensión se diluyó en serie y se inocularon en placas Petri que contenían medio Dyg. Todas las colonias de bacterias se purificaron en el mismo medio. Se evaluó la capacidad diazotrófica de cada bacteria en condiciones microaerofílicas en medio semisólido BMGM. Además, los aislamientos bacterianos que formaron películas se evaluaron también mediante amplificación por PCR para el gen nifH. La diversidad de bacterias nifH+ se analizó por Huella Genética utilizando la Reacción en Cadena de la Polimerasa. Para las cepas seleccionadas, la capacidad de promover el crecimiento de O. sativa como modelo de planta también se evaluó. Se obtuvo un total de 992 cepas bacterianas. Cincuenta y un bacterias fueron capaces de formar películas en el medio semisólido y 38 amplificaron positivamente el fragmento 360bp del gen nifH. De los 38 aislamientos de nifH+, 24 fueron obtenidos de los brotes, mientras que 14 se originaron a partir de las raíces. Los perfiles de PCR-Box mostraron que los aislamientos bacterianos obtenidos en este estudio presentaron una baja similitud con las cepas de referencia pertenecientes a Herbaspirillum, Azospirillum y el género Burkholderia. La capacidad promotora del crecimiento fue confirmada por al menos cinco aislamientos. Para esta bacteria, la raíz y brote mostraron resultados de crecimiento mayores en comparación con los observados en las plantas inoculadas con las cepas de referencia. Estos resultados indican que O. glumaepatula es colonizada por una muy diversa comunidad diazotrófica en la Amazonia brasileña. Se están llevando a cabo otras investigaciones para esclarecer la taxonomía de estas cepas y sus mecanismos para promover el crecimiento.

  4. INÓCULO DE HONGOS DE MICORRIZA ARBUSCULAR EN PASTURAS DE Brachiaria decumbens (POACEAE EN ZONAS DE LOMA Y VEGA Inoculum of Arbuscular Mycorrhizal Fungi on Brachiaria decumbens (Poaceae Pastures in Valley and Hilly Terrain

    Directory of Open Access Journals (Sweden)

    RAÚL HERNANDO POSADA ALMANZA

    2007-06-01

    Full Text Available Los factores que influyen en la distribución del inóculo de hongos micorrícicos arbusculares (micelio externo y esporas son diversos. Entre ellos pueden mencionarse la especie vegetal predominante, el pH, la humedad del suelo, la conductividad, el contenido de fósforo, nutrientes y de metales pesados. Muchos de los reportes de la literatura son contradictorios y basados en estudios realizados en zonas templadas; en condiciones tropicales es difícil determinar los factores edáficos y ambientales que estimulan la producción de inóculo y la forma en que lo hacen. Brachiaria decumbens, como especie de pasto predominante en paisajes de loma y vega en el piedemonte amazónico colombiano, ha sido poco estudiada en su relación micorrícica. En este estudio se realizó la determinación de la densidad de esporas y micelio externo en 26 zonas cubiertas con B. decumbens, correspondientes a paisajes de loma y vega. Simultáneamente se valoraron el contenido de fósforo disponible (ppm, pH y humedad relativa del suelo (%. Mediante correlaciones de Spearman (rangos y análisis de varianza (ANDEVA de una vía por KruscallWallis, se encontró que el inóculo se distribuye de forma diferente en loma y vega, siendo mayor la densidad de esporas en loma que en vega y más homogéneo en contenido de micelio externo en vega que en loma. No se encontró efecto del fósforo disponible, el pH y la humedad del suelo sobre la densidad de inóculo de HMA.The diversity of factors influencing the distribution of arbuscular mycorrhizal fungi inoculum (spores and hyphae, plant species, pH, soil humidity, conductivity, P availability, nutrients and heavy metals have been reported. Reports are contradictory and mostly supported on data from temperate zones; under tropical conditions it is difficult to determine the edaphycal and environmental factors that stimulate inoculum production, and how it happens. Brachiaria decumbens is the dominant grass species in plain and hilly landscapes on the Amazonian piedmont of Colombia. There are few studies on its mycorrhizal relationships. In this study the spore density and external hyphae were determined in 26 B. decumbens pastures, on plain and hilly landscapes; simultaneously phosphorus availability (ppm, pH, and soil relative humidity (% were measured. Spearman (ranks correlations coefficients and nonparametric KruscallWallis one way ANOVA were performed and found that: the inoculum has a different distribution in plain and hilly, the spore densities were higher in hilly terrain than in plain soils, and the external hyphae were more homogeneous in plain than in hilly terrain. Phosphorus availability, pH and soil humidity have no effect on the density of inoculum of HMA.

  5. Inóculo de hongo de micorriza arbuscular en pasturas de Brachiaria decumbens (Poaceae en zonas de loma y vega Inoculum of Arbuscular Mycorrhizal Fungi on Brachiaria decumbens (Poaceae Pastures in Valley and Hilly Terrain

    Directory of Open Access Journals (Sweden)

    Sánchez Figueroa Adriana Patricia

    2007-04-01

    Full Text Available Los factores que influyen en la distribución del inóculo de hongos micorrícicos arbusculares (micelio externo y esporas son diversos. Entre ellos pueden mencionarse la especie vegetal predominante, el pH, la humedad del suelo, la conductividad, el contenido de fósforo, nutrientes y de metales pesados. Muchos de los reportes de la literatura son contradictorios y basados en estudios realizados en zonas templadas; en condiciones tropicales es difícil determinar los factores edáficos y ambientales que estimulan la producción de inóculo y la forma en que lo hacen. Brachiaria decumbens, como especie de pasto predominante en paisajes de loma y vega en el piedemonte amazónico colombiano, ha sido poco estudiada en su relación micorrícica. En este estudio se realizó la determinación de la densidad de esporas y micelio externo en 26 zonas cubiertas con B. decumbens, correspondientes a paisajes de loma y vega. Simultáneamente se valoraron el contenido de fósforo disponible (ppm, pH y humedad relativa del suelo (%. Mediante correlaciones de Spearman (rangos y análisis de varianza (ANDEVA de una vía por Kruscall-Wallis, se encontró que el inóculo se distribuye de forma diferente en loma y vega, siendo mayor la densidad de esporas en loma que en vega y más homogéneo en contenido de micelio externo en vega que en loma. No se encontró efecto del fósforo disponible, el pH y la humedad del suelo sobre la densidad de inóculo de HMA.The diversity of factors influencing the distribution of arbuscular mycorrhizal fungi inoculum (spores and hyphae, plant species, pH, soil humidity, conductivity, P availability, nutrients and heavy metals have been reported. Reports are contradictory and mostly supported on data from temperate zones; under tropical conditions it is difficult to determine the edaphycal and environmental factors that stimulate inoculum production, and how it happens. Brachiaria decumbens is the dominant grass species in plain and hilly landscapes on the Amazonian piedmont of Colombia. There are few studies on its mycorrhizal relationships. In this study the spore density and external
    hyphae were determined in 26 B. decumbens pastures, on plain and hilly landscapes; simultaneously phosphorus availability (ppm, pH, and soil relative humidity (% were measured. Spearman (ranks correlations coefficients and non-parametric Kruscall- Wallis one way ANOVA were performed and found that: the inoculum has a different distribution in plain and hilly, the spore densities were higher in hilly terrain than in plain soils, and the external hyphae were more homogeneous in plain than in hilly terrain. Phosphorus availability, pH and soil humidity have no effect on the density of inoculum of HMA.

  6. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae: hybrids and their genitors = Comportamento meiótico em Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae: híbridos e seus progenitores

    Directory of Open Access Journals (Sweden)

    Cleide Pessim

    2010-07-01

    Full Text Available Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic tetraploid male plants, including the genitors, were cytologically evaluated in the meiotic process throughout conventional methodology. Hybrids and genitors showed high meiotic stability. The percentage of abnormal cells among them ranged from 6.7 to 14.2%. Abnormalities recorded were irregular chromosome segregation, chromosome stickiness, and absence of the first cytokinesis, but the latter did not compromise pollen viability. Multivalent chromosome configurations at diakinesis, ranging from one to three quadrivalents, suggest that genetic recombination and introgression of some genes can be expected in the hybrids. Based on meiotic stability, the hybrids should be selected for high seed production, and the genitors could remain in the program participating in other intraspecific crosses.Panicum maximum Jacq. é uma das gramíneas mais cultivadas no mundo. O programa de hibridização intraespecífica, desenvolvido pela Embrapa Gado de Corte objetiva combinar diversas características agronômicas em uma única planta com alta produção de sementes. Quatro híbridosintraespecíficos, originados a partir do cruzamento entre fêmeas sexuais tetraploidizadas artificialmente com plantas apomíticas, incluindo os respectivos genitores, foram citologicamente avaliados em seu processo meiótico por meio de metodologia convencional.Híbridos e genitores apresentaram alta estabilidade meiótica, e a percentagem de anormalidades meióticas entre eles variou de 6,7 a 14,2%. As anormalidades encontradas foram segregação irregular de cromossomos, aderências e ausência de citocinese, mas esta última não comprometeu a viabilidade do pólen. Configurações cromossômicas emmultivalentes na diacinese, que variam de um a quatro quadrivalentes, sugerem que a recombinação e a introgressão de alguns genes pode ser esperada em híbridos. Com base na estabilidade meiótica observada, os híbridos poderão ser selecionados para alta produção de sementes, e os genitores podem permanecer no programa de melhoramento participandoem outros cruzamentos intraespecíficos.

  7. Aspectos da biologia e fenologia de Oryza latifolia Desv. (Poaceae no Pantanal sul-mato-grossense Aspects of the biology and phenology of Oryza latifolia Desv. (Poaceae in the Pantanal wetland in Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Esther Campagna Bertazzoni

    2011-06-01

    Full Text Available Oryza latifolia, uma espécie silvestre de arroz, aquática emergente, tolerante a inundação, tem vasta ocorrência nos campos inundáveis do Pantanal, principalmente na sub-região do Paraguai. O objetivo deste trabalho foi descrever aspectos da biologia e fenologia de O. latifolia em duas áreas ao longo do rio Paraguai. Cinco manchas de arroz foram analisadas em cada área. Um quadro (1m x 1m era lançado com 20 repetições mensalmente em cada mancha, e foi estimada a porcentagem de cobertura, botão, floração, frutificação e panícula seca, medindo ainda a profundidade de água na mancha de dez/2006-nov/2007. A porcentagem de cobertura foi influenciada pelo nível da água na mancha, atingindo 80% durante a cheia nas duas áreas; o estabelecimento de plântulas ocorreu no período da seca, apenas nas bordas das manchas. A fase reprodutiva da espécie é curta e tem início durante a cheia. Esse período é correlacionado a um conjunto de variáveis ambientais como comprimento do dia e o nível da água. A dispersão da semente ocorre no início da vazante por barocoria, hidrocoria e zoocoria, e suas sementes permanecem viáveis, por cinco meses, até o período da seca.Oryza latifolia, a wild species of rice, aquatic emergent, tolerant of flooding, occurs on floodplains of the Pantanal wetland, mainly in the Paraguay River sub-region. The aim of this study was to describe aspects of the biology and phenology of O. latifolia in two areas (Serra do Amolar and Bracinho along the Paraguay River, in the township of Corumbá (state of Mato Grosso do Sul. Five patches of wild rice were observed in each area. Twenty replicates of quadrats (1m x 1m were randomly established monthly in each patch, and percent cover was estimated; fl owering, fruiting, production of dry inflorescence and water depth were monitored from December 2006 to November 2007. Percent cover is correlated with water level and day length in the plots, reaching up to 80% at flood time in both areas. Recruitment of seedlings occurs during the dry season only on the plot edges. The reproductive phase of the species is short and starts after the flood peak. This period is correlated with a set of environmental variables such as day length and water level. Dispersal occurs by barochory, hydrochory and ictiochory, at the onset of receding water, and seeds stay viable for five months up to the dry period.

  8. Meiotic behavior in Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): hybrids and their genitors = Comportamento meiótico em Panicum maximum Jacq. (Poaceae: Panicoideae: Paniceae): híbridos e seus progenitores

    OpenAIRE

    Cleide Pessim; Maria Suely Pagliarini; Liana Jank; Alice Maria de Souza Kaneshima; Andréa Beatriz Mendes Bonato

    2010-01-01

    Panicum maximum Jacq. is one of the most cultivated grasses in the world. The intraspecific hybridization breeding program underway at Embrapa Beef Cattle aims at combining several agronomic characteristics in a single plant with high seed production. Four intraspecific hybrids originated from the cross between sexual tetraploid female plants with apomictic tetraploid male plants, including the genitors, were cytologically evaluated in the meiotic process throughout conventional methodology. ...

  9. Poaceae, Secale spp. and Artemisia spp. pollen in the air at two sites of different degrees of urbanisation

    Directory of Open Access Journals (Sweden)

    Aleksandra Kruczek

    2017-03-01

    [b]Results.[/b] The first pollen grains to appear in the air are those produced by rye, followed by those produced by grass and wormwood. The pollen seasons of grasses and wormwood started about one week earlier in Gudowo than in Szczecin, while the pollen season of rye started at almost the same time in the country and in the city. Airborne pollen counts of grasses, rye and wormwood were much higher in the country than in the city. The differences most probably result from the different floristic composition at these two sites and reflect the local contribution of the taxa studied in the country. Conclusions. The risk of allergy caused by the pollen of the taxa analysed was much higher in Gudowo (in the country, than in Szczecin city

  10. The evolution pattern of rDNA ITS in Avena and phylogenetic relationship of the Avena species (Poaceae: Aveneae).

    Science.gov (United States)

    Peng, Yuan-Ying; Baum, Bernard R; Ren, Chang-Zhong; Jiang, Qian-Tao; Chen, Guo-Yue; Zheng, You-Liang; Wei, Yu-Ming

    2010-10-01

    Ribosomal ITS sequences are commonly used for phylogenetic reconstruction because they are included in rDNA repeats, and these repeats often undergo rapid concerted evolution within and between arrays. Therefore, the rDNA ITS copies appear to be virtually identical and can sometimes be treated as a single gene. In this paper we examined ITS polymorphism within and among 13 diploid (A and C genomes), seven tetraploid (AB, AC and CC genomes) and four hexaploid (ACD genome) to infer the extent and direction of concerted evolution, and to reveal the phylogenetic and genome relationship among species of Avena. A total of 170 clones of the ITS1-5.8S-ITS2 fragment were sequenced to carry out haplotype and phylogenetic analysis. In addition, 111 Avena ITS sequences retrieved from GenBank were combined with 170 clones to construct a phylogeny and a network. We demonstrate the major divergence between the A and C genomes whereas the distinction among the A and B/D genomes was generally not possible. High affinity among the A(d) genome species A. damascena and the ACD genome species A. fatua was found, whereas the rest of the ACD genome hexaploids and the AACC tetraploids were highly affiliated with the A(l) genome diploid A. longiglumis. One of the AACC species A. murphyi showed the closest relationship with most of the hexaploid species. Both C(v) and C(p) genome species have been proposed as paternal donors of the C-genome carrying polyploids. Incomplete concerted evolution is responsible for the observed differences among different clones of a single Avena individual. The elimination of C-genome rRNA sequences and the resulting evolutionary inference of hexaploid species are discussed.

  11. New additions to the Flora of Ethiopia and Eritrea in the families Euphorbiaceae, Fabaceae (Leguminosae), Lamiaceae, Campanulaceae, Eriocaulaceae and Poaceae

    DEFF Research Database (Denmark)

    Friis, Ib; Phillips, Sylvia M.; Gilbert, Michael G.

    2011-01-01

    During recent field work by Ib Friis and Sally Bidgood six collections were collected that did not represent taxa accounted for in the Flora of Ethiopia and Eritrea. These were Phyllanthus chevalieri, Indigofer bracteolata, Wahlenbergia paludicola, Clerodendrum triflorum, Tragus mongolorum and Hy...

  12. Characterization of genome in tetraploid StY species of Elymus (Triticeae: Poaceae) using sequential FISH and GISH.

    Science.gov (United States)

    Liu, Ruijuan; Wang, Richard R-C; Yu, Feng; Lu, Xingwang; Dou, Quanwen

    2017-08-01

    Genomes of ten species of Elymus, either presumed or known as tetraploid StY, were characterized using fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH). These tetraploid species could be grouped into three categories. Type I included StY genome reported species-Roegneria pendulina, R. nutans, R. glaberrima, R. ciliaris, and Elymus nevskii, and StY genome presumed species-R. sinica, R. breviglumis, and R. dura, whose genome could be separated into two sets based on different GISH intensities. Type I genome constitution was deemed as putative StY. The St genome were mainly characterized with intense hybridization with pAs1, fewer AAG sites, and linked distribution of 5S rDNA and 18S-26S rDNA, while the Y genome with less intense hybridization with pAs1, more varied AAG sites, and isolated distribution of 5S rDNA and 18S-26S rDNA. Nevertheless, further genomic variations were detected among the different StY species. Type II included E. alashanicus, whose genome could be easily separated based on GISH pattern. FISH and GISH patterns suggested that E. alashanicus comprised a modified St genome and an unknown genome. Type III included E. longearistatus, whose genome could not be separated by GISH and was designated as St(l)Y(l). Notably, a close relationship between S(l) and Y(l) genomes was observed.

  13. Stigma receptivity, mode of reproduction, and mating system in Mesosetum chaseae Luces (Poaceae), a native grass of the Brazilian Pantanal.

    Science.gov (United States)

    Silva, L A C; Pagliarini, M S; Santos, S A; Valle, C B

    2013-10-25

    Mesosetum chaseae Luces, known regionally as "grama-do-cerrado", is abundant in the Pantanal region in Brazil and contributes significantly to livestock and environmental conservation. This species is under basic studies at Embrapa Pantanal (Nhecolândia subregion, Pantanal, Corumbá, MS, Brazil). In this study, we present data about stigma receptivity, mode of reproduction, and mating system for 10 accessions collected in Nhecolândia subregion (Pantanal). Stigma receptivity was optimal, producing innumerous oxygen bubbles upon testing with hydrogen peroxidase. Clarified ovaries analyzed under interference microscopy showed an embryo sac of the Polygonum type, typical of sexual species. The mating system, tested in protected flowers, indicated allogamy. These data are important for subsidizing future breeding programs for this species.

  14. Evolution of AGL6-like MADS box genes in grasses (Poaceae): ovule expression is ancient and palea expression is new.

    Science.gov (United States)

    Reinheimer, Renata; Kellogg, Elizabeth A

    2009-09-01

    AGAMOUS-like6 (AGL6) genes encode MIKC-type MADS box transcription factors and are closely related to SEPALLATA and AP1/FUL-like genes. Here, we focus on the molecular evolution and expression of the AGL6-like genes in grasses. We have found that AGL6-like genes are expressed in ovules, lodicules (second whorl floral organs), paleas (putative first whorl floral organs), and floral meristems. Each of these expression domains was acquired at a different time in evolution, indicating that each represents a distinct function of the gene product and that the AGL6-like genes are pleiotropic. Expression in the inner integument of the ovule appears to be an ancient expression pattern corresponding to the expression of the gene in the megasporangium and integument in gymnosperms. Expression in floral meristems appears to have been acquired in the angiosperms and expression in second whorl organs in monocots. Early in grass evolution, AGL6-like orthologs acquired a new expression domain in the palea. Stamen expression is variable. Most grasses have a single AGL6-like gene (orthologous to the rice [Oryza sativa] gene MADS6). However, rice and other species of Oryza have a second copy (orthologous to rice MADS17) that appears to be the result of an ancient duplication.

  15. Produção de mudas de bambu Guadua angustifolia Kunth (Poaceae) por propagação vegetativa.

    OpenAIRE

    Fonseca,Fernanda Karina Pereira da

    2007-01-01

    The bamboo is a tropical, renewable, perennial culture of fast growth and with several uses. However, its use and research is moistly restricted to Asian countries. In Brazil the demand for bamboo has increased in the last years. From November 2005 to September 2006, experiments were carried out with the objective to evaluate the ability of Guadua angustifolia to produce new plants from cuttings of secondary branches and clump division of two years seedlings. There were evaluated the sp...

  16. Population genetic analysis of Bromus tectorum (Poaceae) indicates recent range expansion may be facilitated by specialist genotypes

    Science.gov (United States)

    Keith R. Merrill; Susan E. Meyer; Craig E. Coleman

    2012-01-01

    The mechanisms for range expansion in invasive species depend on how genetic variation is structured in the introduced range. This study examined neutral genetic variation in the invasive annual grass Bromus tectorum in the Intermountain Western United States. Patterns of microsatellite (SSR) genotype distribution in this highly inbreeding species were used to make...

  17. Surface-dwelling and subterranean invertebrate fauna associated with giant reed (Arundo donax Poaceae) in Southern California

    Science.gov (United States)

    Lovich, Robert E.; Ervin, Edward L.; Fisher, Robert N.

    2009-01-01

    In the southwestern United States giant reed, Arundo donax, is a non-native invasive plant that has become widely established in moist places and forms its largest stands along riparian corridors. The most widely reported negative effects include competition with native species, increased rate of transpiration, increased potential for wildfires, and stream channel and bank alteration. However, little is known about the faunal communities associated with this plant and the potential effects on native fauna. In this study, we focused our efforts on determining the faunal composition specifically from rhizome clumps of A. donax from a site located along the Santa Margarita River in San Diego County, California. A total of 2590 individual macro-invertebrates were collected and identified, and represented 64 species from 7 classes. No sensitive species and few vertebrates were found to be in association with A. donax rhizome clumps. Four non-native invertebrate species made up 43% of the total number of captured invertebrates, and 31% of the sampled invertebrates were confirmed as native species. This study demonstrates that A. donax rhizome clumps, and the soils associated with them, provide habitat for several native macro-invertebrate species, but can be dominated by a greater abundance of non-native species.

  18. The monophyly of Chimonocalamus and conflicting gene trees in Arundinarieae (Poaceae: Bambusoideae) inferred from four plastid and two nuclear markers.

    Science.gov (United States)

    Yang, Hong-Mei; Zhang, Yu-Xiao; Yang, Jun-Bo; Li, De-Zhu

    2013-08-01

    Arundinarieae is not only a taxonomically difficult group of bamboos, but also a troublesome one in molecular phylogenetics. In this study, the phylogeny of 50 species in Arundinarieae with an emphasis on Chimonocalamus was reconstructed, using four plastid regions (rpl32-trnL, trnT-trnL, rps16-trnQ and trnC-rpoB) and two nuclear genes (GBSSI and LEAFY). The plastid phylogeny was largely consistent with the previous studies, except that Ampelocalamus calcareus was newly recovered as lineage XI. The nuclear phylogeny of LEAFY had better resolution than the one of GBSSI. The close relationships among Ampelocalamus, Drepanostachyum and Himalayacalamus were retrieved by the nuclear datasets. Alpine Bashania, Chimonocalamus, Thamnocalamus, and species currently placed in Fargesia and Yushania formed a clade in the LEAFY and combined nuclear phylogenies. Some of the gene tree disparities revealed in previous studies were reconfirmed. Chimonocalamus was recovered as monophyletic by combining the nuclear genes, but as polyphyletic in plastid analyses. Insufficient informative characters, hybridization, plastid capture or incomplete plastid lineage sorting could be responsible for the incongruent phylogenetic positions of some species of Chimonocalamus. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Multilocus phylogeny and phylogenomics of Eriochrysis P. Beauv. (Poaceae-Andropogoneae): Taxonomic implications and evidence of interspecific hybridization.

    Science.gov (United States)

    Welker, Cassiano A D; Souza-Chies, Tatiana T; Longhi-Wagner, Hilda M; Peichoto, Myriam Carolina; McKain, Michael R; Kellogg, Elizabeth A

    2016-06-01

    Species delimitation is a vital issue concerning evolutionary biology and conservation of biodiversity. However, it is a challenging task for several reasons, including the low interspecies variability of markers currently used in phylogenetic reconstructions and the occurrence of reticulate evolution and polyploidy in many lineages of flowering plants. The first phylogeny of the grass genus Eriochrysis is presented here, focusing on the New World species, in order to examine its relationships to other genera of the subtribe Saccharinae/tribe Andropogoneae and to define the circumscriptions of its taxonomically complicated species. Molecular cloning and sequencing of five regions of four low-copy nuclear genes (apo1, d8, ep2-ex7 and ep2-ex8, kn1) were performed, as well as complete plastome sequencing. Trees were reconstructed using maximum parsimony, maximum likelihood, and Bayesian inference analyses. The present phylogenetic analyses indicate that Eriochrysis is monophyletic and the Old World E. pallida is sister to the New World species. Subtribe Saccharinae is polyphyletic, as is the genus Eulalia. Based on nuclear and plastome sequences plus morphology, we define the circumscriptions of the New World species of Eriochrysis: E. laxa is distinct from E. warmingiana, and E. villosa is distinct from E. cayennensis. Natural hybrids occur between E. laxa and E. villosa. The hybrids are probably tetraploids, based on the number of paralogues in the nuclear gene trees. This is the first record of a polyploid taxon in the genus Eriochrysis. Some incongruities between nuclear genes and plastome analyses were detected and are potentially caused by incomplete lineage sorting and/or ancient hybridization. The set of low-copy nuclear genes used in this study seems to be sufficient to resolve phylogenetic relationships and define the circumscriptions of other species complexes in the grass family and relatives, even in the presence of polyploidy and reticulate evolution. Complete plastome sequencing is also a promising tool for phylogenetic inference. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Characterization of St and Y genome in StStYY Elymus species (Triticeae: Poaceae) using Sequential FISH and GISH

    Science.gov (United States)

    Tetraploid species possessing StY genome could be donors to hexaploid species having StYH, StYP, or StYW genome constitution in the genus Elymus, and a few of StY species have been intensely studied for inferring the origin of the Y genome. In this study, genome characterization of St and Y genome w...

  1. The effects of gap size and disturbance type on invasion of wet pine savanna by cogongrass, Imperata cylindrica (Poaceae)

    Science.gov (United States)

    King, S.E.; Grace, J.B.

    2000-01-01

    Cogongrass is a nonindigenous species perceived to threaten native communities of the southeastern United States through modification of species composition and alteration of community processes. To examine how gap size and disturbance type influence the invasion of wet pine savannas by cogongrass, we performed three field experiments to evaluate the response of cogongrass seeds and transplanted seedlings to four different gap sizes, four types of site disturbance, and recent burning of savanna vegetation. Cogongrass germinated, survived, and grew in all gap sizes, from 0 to 100 cm in diameter. Similarly, disturbance type had no effect on germination or seedling and transplant survival. Tilling, however, significantly enhanced transplanted seedling growth, resulting in a tenfold increase in biomass over the other disturbance types. Seedling survival to 1 and 2 mo was greater in burned savanna than unburned savanna, although transplant survival and growth were not affected by burning. Results of this study suggest that cogongrass can germinate, survive, and grow in wet pine savanna communities regardless of gap size or type of disturbance, including burning. Burning of savanna vegetation may enhance establishment by improving early seedling survival, and soil disturbance can facilitate invasion of cogongrass by enhancing plant growth.

  2. Poaceae, Secale spp. and Artemisia spp. pollen in the air at two sites of different degrees of urbanisation.

    Science.gov (United States)

    Kruczek, Aleksandra; Puc, Małgorzata; Wolski, Tomasz

    2017-03-21

    Among herbal plants, most cases of allergic reactions, like seasonal inflammation of nasal mucosa, conjunctivitis and pollen asthma, are related to the allergens from grass pollen. As the blossoming and pollination of rye is known to start the pollen season of grasses, information about the airborne rye pollen count permits alerting the people allergic to certain allergens contained in rye pollen. An important cause of allergy is also the pollen from wormwood, blossoming in late summer, as its two main allergens produce cross-reactions with many other plant allergens. The aim of the study was to evaluate the risk of allergic reactions in persons with pollinosis on the basis of the pollen calendar, analysis of concentrations of pollen grains of grass and rye, and comparison of diurnal pattern of airborne pollen grain concentrations at two sites with different degrees of urbanisation (Gudowo in the country and the city of Szczecin) in 2012-2014. The concentration of pollen was measured by the volume method. Length of the pollination season was determined by the method of 98%, assuming that the beginning and the end of the pollen season are the days on which 1% and 99% of the annual sum of pollen appeared. The first pollen grains to appear in the air are those produced by rye, followed by those produced by grass and wormwood. The pollen seasons of grasses and wormwood started about one week earlier in Gudowo than in Szczecin, while the pollen season of rye started at almost the same time in the country and in the city. Airborne pollen counts of grasses, rye and wormwood were much higher in the country than in the city. The differences most probably result from the different floristic composition at these two sites and reflect the local contribution of the taxa studied in the country. The risk of allergy caused by the pollen of the taxa analysed was much higher in Gudowo (in the country), than in Szczecin city.

  3. What drivers phenotypic divergence in Leymus chinensis (Poaceae) on large-scale gradient, climate or genetic differentiation?

    Science.gov (United States)

    Yuan, Shan; Ma, Linna; Guo, Chengyuan; Wang, Renzhong

    2016-05-01

    Elucidating the driving factors among-population divergence is an important task in evolutionary biology, however the relative contribution from natural selection and neutral genetic differentiation has been less debated. A manipulation experiment was conducted to examine whether the phenotypic divergence of Leymus chinensis depended on climate variations or genetic differentiations at 18 wild sites along a longitudinal gradient from 114 to 124°E in northeast China and at common garden condition of transplantation. Demographical, morphological and physiological phenotypes of 18 L. chinensis populations exhibited significant divergence along the gradient, but these divergent variations narrowed significantly at the transplantation. Moreover, most of the phenotypes were significantly correlated with mean annual precipitation and temperature in wild sites, suggesting that climatic variables played vital roles in phenotypic divergence of the species. Relative greater heterozygosity (HE), genotype evenness (E) and Shannon-Wiener diversity (I) in western group of populations suggested that genetic differentiation also drove phenotypic divergence of the species. However, neutral genetic differentiation (FST = 0.041) was greatly lower than quantitative differentiation (QST = 0.199), indicating that divergent selection/climate variable was the main factor in determining the phenotypic divergence of the species along the large-scale gradient.

  4. [Valve-like structures in motor cells of the leaf of Distichlis spicata "Yesen 4A" (Poaceae)].

    Science.gov (United States)

    Semenova, G A

    2015-01-01

    The salt gland of the leaf of Distichlis directly contacts the cells of interfascicular aquiferous parenchyma (motor cells). The cytoplasmic strand of motor cells produce deep invaginations, which form with the participation of mitochondria. The constriction of the cytoplasmic strand at the site of the localization of mitochondria leads to the fusion of the tonoplast and plasmalemma with mitochondrial membranes and the formation of a thin one-layer plate, a valve. At this locus, vacuolar and apoplast spaces are separated only by a valve. The cytoplasm of motor cells is filled with electron dense granules, which are considered as contractile elements. It is assumed that the cytoplasmic strand is involved in the reduction of the volume, which results in the generation of pressure on the valve. This leads to the direct throw-in of water into the apoplast space adjacent to the salt gland.

  5. An empirical test of the treatment of indels during optimization alignment based on the phylogeny of the genus Secale (Poaceae)

    DEFF Research Database (Denmark)

    Petersen, Gitte; Seberg, Ole; Aagesen, Lone

    2004-01-01

    The ability of the program POY, implementing optimization alignment, to deal with major indels is explored and discussed in connection with a phylogenetic analysis of the genus Secale based on partial Adhl sequences. The Adhl sequences used span exon 2-4. Nearly all variation is found in intron 2...

  6. Phenotypic plasticity of invasive Spartina densiflora (Poaceae) along a broad latitudinal gradient on the Pacific Coast of North America

    Science.gov (United States)

    We examined morphological and physiological leaf traits of Spartina densiflora plants in populations from invaded estuarine sites across broad latitudinal and climate gradients along the Pacific west coast of North America, and in favourable conditions in a common garden experiment. We hypothesized ...

  7. Multi-locus plastid phylogenetic biogeography supports the Asian hypothesis of the temperate woody bamboos (Poaceae: Bambusoideae).

    Science.gov (United States)

    Zhang, Xian-Zhi; Zeng, Chun-Xia; Ma, Peng-Fei; Haevermans, Thomas; Zhang, Yu-Xiao; Zhang, Li-Na; Guo, Zhen-Hua; Li, De-Zhu

    2016-03-01

    In this paper we investigate the biogeography of the temperate woody bamboos (Arundinarieae) using a densely-sampled phylogenetic tree of Bambusoideae based on six plastid DNA loci, which corroborates the previously discovered 12 lineages (I-XII) and places Kuruna as sister to the Chimonocalamus clade. Biogeographic analyses revealed that the Arundinarieae diversified from an estimated 12 to 14Mya, and this was followed by rapid radiation within the lineages, particularly lineages IV, V and VI, starting from c. 7-8Mya. It is suggested that the late Miocene intensification of East Asian monsoon may have contributed to this burst of diversification. The possibilities of the extant Sri Lankan and African temperate bamboo lineages representing 'basal elements' could be excluded, indicating that there is no evidence to support the Indian or African route for migration of temperate bamboo ancestors to Asia. Radiations from eastern Asia to Africa, Sri Lanka, and to North America all are likely to have occurred during the Pliocene, to form the disjunct distribution of Arundinarieae we observe today. The two African lineages are inferred as being derived independently from Asian ancestors, either by overland migrations or long-distance dispersals. Beringian migration may explain the eastern Asian-eastern North American disjunction. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Phylogeny and molecular evolution of the Acc1 gene within the StH genome species in Triticeae (Poaceae).

    Science.gov (United States)

    Fan, Xing; Sha, Li-Na; Wang, Xiao-Li; Zhang, Hai-Qin; Kang, Hou-Yang; Wang, Yi; Zhou, Yong-Hong

    2013-10-15

    To estimate the phylogeny and molecular evolution of a single-copy gene encoding plastid acetyl-CoA carboxylase (Acc1) within the StH genome species, two Acc1 homoeologous sequences were isolated from nearly all the sampled StH genome species and were analyzed with those from 35 diploid taxa representing 19 basic genomes in Triticeae. Sequence diversity patterns and genealogical analysis suggested that (1) the StH genome species from the same areas or neighboring geographic regions are closely related to each other; (2) the Acc1 gene sequences of the StH genome species from North America and Eurasia are evolutionarily distinct; (3) Dasypyrum has contributed to the nuclear genome of Elymus repens and Elymus mutabilis; (4) the StH genome polyploids have higher levels of sequence diversity in the H genome homoeolog than the St genome homoeolog; and (5) the Acc1 sequence may evolve faster in the polyploid species than in the diploids. Our result provides some insight on evolutionary dynamics of duplicate Acc1 gene, the polyploidy speciation and phylogeny of the StH genome species. © 2013 Elsevier B.V. All rights reserved.

  9. Phylogenetic inference and SSR characterization of tropical woody bamboos tribe Bambuseae (Poaceae: Bambusoideae) based on complete plastid genome sequences.

    Science.gov (United States)

    Vieira, Leila do Nascimento; Dos Anjos, Karina Goulart; Faoro, Helisson; Fraga, Hugo Pacheco de Freitas; Greco, Thiago Machado; Pedrosa, Fábio de Oliveira; de Souza, Emanuel Maltempi; Rogalski, Marcelo; de Souza, Robson Francisco; Guerra, Miguel Pedro

    2016-05-01

    The complete plastome sequencing is an efficient option for increasing phylogenetic resolution and evolutionary studies, as well as may greatly facilitate the use of plastid DNA markers in plant population genetic studies. Merostachys and Guadua stand out as the most common and the highest potential utilization bamboos indigenous of Brazil. Here, we sequenced the complete plastome sequences of the Brazilian Guadua chacoensis and Merostachys sp. to perform full plastome phylogeny and characterize the occurrence, type, and distribution of SRRs using 20 Bambuseae species. The determined plastome sequence of Merostachys sp. and G. chacoensis is 136,334 and 135,403 bp in size, respectively, with an identical gene content and typical quadripartite structure consisting of a pair of IRs separated by the LSC and SSC regions. The Maximum Likelihood and Bayesian Inference analyses produced phylogenomic trees identical in topology. These trees supported monophyly of Paleotropical and Neotropical Bamboos clades. The Neotropical bamboos segregated into three well-supported lineages, Chusqueinae, Guaduinae, and Arthrostylidiinae, with the last two forming a well-supported sister relationship. Paleotropical bamboos segregated into two well-supported lineages, Hickeliinae and Bambusinae + Melocanninae. We identified 141.8 cpSSR in Bambuseae plastomes and an inferior value (38.15) for plastome coding sequences. Among them, we identified 16 polymorphic SSR loci, with number of alleles varying from 3 to 10. These 16 polymorphic cpSSR loci in Bambuseae plastome can be assessed for the intraspecific level of polymorphism, leading to innovative highly sensitive phylogeographic and population genetics studies for this tribe.

  10. [Modeling of introgression between Elymus caninus and E. fibrosus (Poaceae) and their registration using one-dimensional SDS electrophoresis].

    Science.gov (United States)

    Gerus, D E; Agafonov, A V

    2006-12-01

    Artificial sexual hybrids between Elymus caninus (L.) L. and E. fibrosus (Schrebk) Tzvel. were experimentally examined in generations F1-F5. The possibility of genetic introgression between these species was shown. Morphologically, the hybrid plants can be assigned to either of the parental species or to variety E. caninus var. muticus (Holmb.) Karlsson. Some traits (spike density, leaf blade width, leaf blade pubescence, awns of lemmas) exhibited considerable variation. Polypeptide spectra of endosperm proteins were characterized in the initial parental biotypes and the hybrid progeny, using a gel-buffer SDS electrophoresis system. It was suggested that successful interspecies hybridization requires backcrosses or normalizing crosses. The possibility of sexual genetic exchange enables to utilize the gene pools of the two species to transfer the required traits in selection forage forms.

  11. The hybrid origin of Calamagrostis ×gracilescens (Poaceae in Poland inferred from morphology and AFLP data

    Directory of Open Access Journals (Sweden)

    Beata Paszko

    2011-01-01

    Full Text Available The morphology of Calamagrostis canescens and C. stricta recorded in the Małopolska Upland (the vicinity of Zbijów Mały, ca. 10 km northeast of the town of Skarżysko-Kamienna, Central Poland was examined due to intermediate individuals found in sympatric populations of these species. Both putative parents as well as individuals that appeared hybrid-like were found in an extensive, wet hay-meadow. Various vegetative and reproductive characteristics were studied to identify hybrids. Interestingly, Polish accessions of C. ×gracilescens exhibited some degree of morphological intermediacy but resembled C. stricta in spikelet morphology. Branching of the mid-culm, the number of nodes per culm, callus hair length and relative callus hair length are the best characters to distinguish the Polish C. ×gracilescens. AFLP analysis proved to be suitable for detecting recent hybridization events between C. canescens and C. stricta. Analysis of the Bayesian clustering analysis showed that C. ×gracilescens were subjected to gene flow from the C. canescens gene pool as well as from the C. stricta gene pool.

  12. Description and interpretation of the bracts epidermis of Gramineae (Poaceae) with rotated image with maximum average power spectrum (RIMAPS) technique.

    Science.gov (United States)

    Favret, Eduardo A; Fuentes, Néstor O; Molina, Ana M; Setten, Lorena M

    2008-10-01

    During the last few years, RIMAPS technique has been used to characterize the micro-relief of metallic surfaces and recently also applied to biological surfaces. RIMAPS is an image analysis technique which uses the rotation of an image and calculates its average power spectrum. Here, it is presented as a tool for describing the morphology of the trichodium net found in some grasses, which is developed on the epidermal cells of the lemma. Three different species of grasses (herbarium samples) are analyzed: Podagrostis aequivalvis (Trin.) Scribn. & Merr., Bromidium hygrometricum (Nees) Nees & Meyen and Bromidium ramboi (Parodi) Rúgolo. Simple schemes representing the real microstructure of the lemma are proposed and studied. RIMAPS spectra of both the schemes and the real microstructures are compared. These results allow inferring how similar the proposed geometrical schemes are to the real microstructures. Each geometrical pattern could be used as a reference for classifying other species. Finally, this kind of analysis is used to determine the morphology of the trichodium net of Agrostis breviculmis Hitchc. As the dried sample had shrunk and the microstructure was not clear, two kinds of morphology are proposed for the trichodium net of Agrostis L., one elliptical and the other rectilinear, the former being the most suitable.

  13. Morphological, phylogenetic, and ecological diversity of the new model species Setaria viridis (Poaceae: Paniceae) and its close relatives.

    Science.gov (United States)

    Layton, Daniel J; Kellogg, Elizabeth A

    2014-03-01

    Species limits of the emerging model organism Setaria viridis (tribe Paniceae, subtribe Cenchrinae) are not well defined. It is thought to be related to S. adhaerens, S. faberi, S. verticillata, and S. verticilliformis and in North America occurs with the morphologically similar S. pumila. An integrated approach was taken to evaluate its variation and relationships with the other taxa. Statistical morphology, flow cytometry, molecular phylogenetics, and growth experiments were employed to examine the group's physical variation, polyploidy, evolutionary relationships, and drought ecology, respectively. SETARIA VIRIDIS contributed one genome to the tetraploids S. faberi, S. verticillata, and S. verticilliformis; the other genome of the latter two was contributed by S. adhaerens. Setaria pumila is unrelated. Morphologically, S. viridis is most similar to S. faberi, but all tested accessions of S. viridis were diploid, whereas those of S. faberi were all tetraploid. Principal component analysis of 70 morphological characters consistently separated S. viridis from S. faberi, largely by spikelet characters. The diagnostic morphological characters are not affected by watering. Setaria faberi is far more sensitive to drought, in terms of mortality and morphological stunting, than S. viridis or S. pumila. SETARIA VIRIDIS is a diploid species and has contributed to several polyploid derivatives. The most morphologically similar of the polyploids is S. faberi, which differs in spikelet features, phylogenetics, genome size, and ecological response to drought. Researchers using field-collected S. viridis as a model organism will benefit from the clear delimitation provided in this study.

  14. The variability of reed [Phragmites australis (cav. Trin. ex Steud. (Poaceae] populations expressed in morphological traits of panicles

    Directory of Open Access Journals (Sweden)

    Maria Krzakowa

    2011-01-01

    Full Text Available Using a transect technique, each of 12 reed Phragmites australis (Cav. Trin ex Steud. populations collected in middle part of Odra River-basin, represented by more than 30 plants, were compared with 3 populations from other part of the country and 1 from France. Each panicle was examined according to 15 morphological traits. Results of measurements were subjected to multivariate analysis of variance, to analysis of canonical variables and used for construction of a minimum spanning tree (= dendrite on the basis of the shortest Mahalanobis distances. The obtained results indicate that populations are generally similar. One population from France (Orleans shows visible separateness. It may suggest that morphological traits of panicles may be useful in investigations of the reed P. australis populations of a larger geographical distribution.

  15. Meiotic behaviour in three interspecific three-way hybrids between Brachiaria ruziziensis and B. brizantha (Poaceae: Paniceae)

    Indian Academy of Sciences (India)

    Eleniza De Victor Adamowski; Maria Suely Pagliarini; Cacilda Borges Do Valle

    2008-04-01

    The meiotic behaviour of three three-way interspecific promising hybrids (H17, H27, and H34) was evaluated. These hybrids resulted from the crosses between B. ruziziensis × B. brizantha and crossed to another B. brizantha. Two half-sib hybrids (H27 and H34) presented an aneuploid chromosome number ($2n = 4x = 33$), whereas hybrid H17 was a tetraploid ($2n = 4x = 36$), as expected. Chromosome paired predominantly as multivalents suggesting that genetic recombination and introgression of specific target genes from B. brizantha into B. ruziziensis can be expected. Arrangement of parental genomes in distinct metaphase plates was observed in H27 and H34, which have different male genitors. Hybrids H17 and H34 have the same male genitor, but did not display this abnormality. In H17, abnormalities were more frequent from anaphase II, when many laggard chromosomes appeared, suggesting that each genome presented a different genetic control for meiotic phase timing. Despite the phylogenetic proximity among these two species, these three hybrids presented a high frequency of meiotic abnormalities, mainly those related to irregular chromosome segregation typical of polyploids, H34, 69.1%; H27, 56.1% and H17, 44.9%. From the accumulated results obtained through cytological studies in Brachiaria hybrids, it is evident that cytogenetical analysis is of prime importance in determining which genotypes can continue in the process of cultivar development and which can be successfully used in the breeding. Hybrids with high frequency of meiotic abnormalities can seriously compromise seed production, a key trait in assuring adoption of a new apomictic cultivar of Brachiaria for pasture formation.

  16. What does the 5S rRNA multigene family tell us about the origin of the annual Triticeae (Poaceae)?

    Science.gov (United States)

    Baum, B R; Edwards, T; Johnson, D A

    2013-05-01

    We have investigated the complex relationships among the annual genera within the tribe Triticeae through phylogenetic analyses of the 5S rRNA multigene family. Cloned sequences were assigned to groups of orthologous sequences, called unit classes, that were subjected to several analyses including BLAST (Basic Local Alignment Search Tool) searches to assess possible ancestral relationships with perennial genera; phylogenetic analyses using parsimony (Pars), maximum likelihood (ML), and Bayesian methods; and minimum reticulation networks from the Pars, ML, and Bayesian trees. In this study, we included genera with both annual and perennial species, such as Dasypyrum, Hordeum, and Secale. BLAST pointed to Pseudoroegneria (carrier of the St genome) and possibly Thinopyrum (carrier of the J genome) as the potential next of kin. However, Thinopyrum and Pseudoroegneria have never fallen together on the individual trees with the former generally associated with Crithopsis, Aegilops, Triticum, and Dasypyrum, while the latter is usually associated with the rest of the genera within Triticeae. The "long" unit classes placed Dasypyrum breviaristatum together with Dasypyrum villosum, whereas the "short" unit classes put them far apart on the trees. None of the gene trees alone was able to summarize the complex relationships among the genera, in line with previous results in the Triticeae. However, the application of tools designed to display phylogenetic networks was able to depict the complex links among the genera based on the short and the long gene trees, including the close link between Thinopyrum and Pseudoroegneria suggested by the phylogenetic analyses. In addition, our analyses provide support for the hypothesis that at least some annual Triticeae taxa are derived from their perennial relatives.

  17. Meiotic behaviour in three interspecific three-way hybrids between Brachiaria ruziziensis and B. brizantha (Poaceae: Paniceae).

    Science.gov (United States)

    Adamowski, Eleniza de Victor; Pagliarini, Maria Suely; do Valle, Cacilda Borges

    2008-04-01

    The meiotic behaviour of three three-way interspecific promising hybrids (H17, H27, and H34) was evaluated. These hybrids resulted from the crosses between B. ruziziensis X B. brizantha and crossed to another B. brizantha. Two half-sib hybrids (H27 and H34) presented an aneuploid chromosome number (2n = 4x = 33), whereas hybrid H17 was a tetraploid (2n = 4x = 36), as expected. Chromosome paired predominantly as multivalents suggesting that genetic recombination and introgression of specific target genes from B. brizantha into B. ruziziensis can be expected. Arrangement of parental genomes in distinct metaphase plates was observed in H27 and H34, which have different male genitors. Hybrids H17 and H34 have the same male genitor, but did not display this abnormality. In H17, abnormalities were more frequent from anaphase II, when many laggard chromosomes appeared, suggesting that each genome presented a different genetic control for meiotic phase timing. Despite the phylogenetic proximity among these two species, these three hybrids presented a high frequency of meiotic abnormalities, mainly those related to irregular chromosome segregation typical of polyploids, H34, 69.1%; H27, 56.1% and H17, 44.9%. From the accumulated results obtained through cytological studies in Brachiaria hybrids, it is evident that cytogenetical analysis is of prime importance in determining which genotypes can continue in the process of cultivar development and which can be successfully used in the breeding. Hybrids with high frequency of meiotic abnormalities can seriously compromise seed production, a key trait in assuring adoption of a new apomictic cultivar of Brachiaria for pasture formation.

  18. The karyotype of Festucopsis serpentini (Poaceae Triticeae) from Albania studied by banding techniques and in situ hybridization

    DEFF Research Database (Denmark)

    Linde-Laursen, I.; Seberg, O.; Frederiksen, S.;

    1996-01-01

    The karyotypes of two populations of Festucopsis serpentini (2n = 2x = 14) endemic to Albania were investigated in detail by Giemsa C- and N-banding, AgNO3 staining, and in situ hybridization with an rDNA probe. The complements consisted of 14 large chromosomes, 10 metacentric and 4 SAT-chromosom...

  19. Comparison of the karyotypes ofPsathyrostachys juncea andP. huashanica (Poaceae) studied by banding techniques

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib; Bothmer, R. von

    1986-01-01

    . The patterns of both taxa are polymorphic, supporting that both taxa are outbreeders. The karyotypic characters suggest that P. juncea is more closely related to P. fragilis than either is to P. huashanica. N-banding stains weakly. Silver nitrate staining demonstrates that nucleolus organizers of both species...... have different nucleolus forming capacities. The presence of micronucleoli suggests that both species have an extra unidentified chromosome with nucleolus forming capacity....

  20. Karyotypes of two cytotypes of Paspalum quadrifarium Lam. (Poaceae): an alternative technique for small chromosomes in plants

    OpenAIRE

    Pablo Speranza; Magdalena Vaio; Cristina Mazzella

    2003-01-01

    Paspalum quadrifarium Lam. is a bunchgrass native to Uruguay, Argentina, and southern Brazil. Diploid, triploid, tetraploid and hexaploid cytotypes have been reported for this species of the Quadrifaria group of Paspalum. In this group, a high degree of cytogenetic homology between the genomes of several diploid species has been reported, based on meiotic pairing in interspecific hybrids; multivalent associations would thus be expected in polyploid hybrids. Karyotype analysis could provide us...