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11	Revisão taxonômica do clado tetraploide-brasileiro de Drosera L. (Droseraceae). / Taxonomic revision of the Brazilian-tetraploid clade of Drosera L. (Droseraceae) Paulo Minatel Gonella Silva 12 December 2012 (has links) O gênero Drosera (Droseraceae) compreende cerca de 200 espécies, 30 delas ocorrendo no Brasil. Nesta dissertação, é realizada a revisão taxonômica do clado tetraploide-brasileiro de Drosera, compreendendo 17 espécies e uma variedade. São apresentados e discutidos dados sobre morfologia, ecologia, distribuição geográfica e status de conservação para estas espécies, com mapas de distribuição, ilustrações, fotografias e tabelas comparativas. Os complexos D. graminifolia, D. Montana e D. villosa são discutidos nos capítulos 1, 2 e 3, respectivamente. Além disso, essas três espécies são recircunscritas com base em evidências morfológicas e de sua ecologia. Drosera ascendens, D. spiralis, D. tomentosa e suas duas variedades são restabelecidas, e D. villosa var. latifólia é elevada ao status específico. Drosera chrysolepis é lectotipificada e três novas espécies são descritas. Drosera camporupestris, D. grantsaui, D. graomogolensis, D. quartzicola, D. tentaculata e D. schwackei também pertencem ao clado e são aqui tratadas. Na seção Taxonomia, é apresentada uma chave de identificação e, no anexo II, uma lista com todos os táxons de Drosera ocorrentes no Brasil e aqui aceitos / The genus Drosera (Droseraceae) comprises around 200 species, 30 occurring in Brazil. In this dissertation is carried out the taxonomic revision of the Brazilian-tetraploid clade of Drosera, comprising 17 species and a variety. Here are presented and discussed data on the morphology, ecology, geographic distribution, and conservation status for these species, with distribution maps, drawings, photographs, and comparative tables. The complexes D. graminifolia, D. Montana, and D. villosa are discussed in chapters 1, 2, and 3, respectively. These three species are recircumscribed based on of morphological and ecological evidences. Drosera ascendens, D. spiralis, D. tomentosa and its two varieties are reestablished, and D. villosa var. latifolia is raised to specific rank. Drosera chrysolepis is lectotypified and three new species are described. Drosera camporupestris, D. grantsaui, D. graomogolensis, D. quartzicola, D. tentaculata, and D. schwackei also belong to this clade and are here treated. In section Taxonomy it is presented a dicotomic key and, in appendix II, a list with all Drosera taxa occurring in Brazil here accepted Brasil Clado tetraploide-brasileiro Drosera Droseraceae Espécies novas Morfologia Brazil Brazilian-tetraploid clade Drosera Droseraceae Morphology New species
12	Důsledky polyploidizace pro invazní potenciál druhu Vicia cracca / Impact of polyploidy on the invasive potential of Vicia cracca Líblová, Zuzana January 2014 (has links) This work is about diploids and tetraploids of Vicia cracca species, the two commonly occurring cytotypes. The first part is devoted to the distribution of cytotypes of this species in the secondary range in North America. It was hypothesised that polyploid species become invasive more frequently than diploid species. Their greater success may be given by greater variability of genes obtained by polyploidisation and gene subfunkcionalizing. All invasive populations of Vicia cracca species involved in this study were tetraploid. Based on this we can say that only tetraploids are invasive in this secondary colonized area. Polyploid species can be better competitors thanks to their expected better growth characteristics and stress resistance. Therefore the second part of this work is testing the hypothesis that polyploids are more variable in size of different parts of the plant body and therefore more able to grow even in conditions that are not suitable for diploids. As predicted by the EICA hypothesis (evolution of increased competitive ability), secondary colonized area also provide more space for further evolution and we can expect that growth characteristics of plants from the invasive range will differ from plants of the same ploidy from the original distribution range. This part of the work...
13	Reprodukční izolace diploidů a tetraploidů druhu Vicia cracca a možnosti evoluce tohoto agregátu / Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregate Vlčková, Zuzana January 2014 (has links) Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prereproducitve barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of species of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproctive barriers is 0,956. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants. I prepared one squash of diploid V. cracca using method of in situ hybridization. This method needs to be optimilized for studied taxon.
14	Reprodukční izolace diploidů a tetraploidů druhu Vicia cracca a možnosti evoluce tohoto agregátu / Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregate Vlčková, Zuzana January 2016 (has links) Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prezygotic barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of spieces of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is, I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproductive barriers is 0,990. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants.
15	Reprodukční izolace diploidů a tetraploidů druhu Vicia cracca a možnosti evoluce tohoto agregátu / Reproductive isolation between diploid and tetraploid cytotype of Vicia cracca and possibilities of evolution of this aggregate Vlčková, Zuzana January 2015 (has links) Master thesis investigates reproductive barriers in diploid-polyploid complex of Vicia cracca. Complex with basic chromosome number x=7 consists of diploid (2x=14), tetraploid (4x=28) and rare triploid (3x=21) cytotype. I studied prereproductive barriers between diploid and tetraploid cytotype: phenology of flowering, pollinators' behavior (preference of spieces of pollinators to cytotypes, sequence of visited cytotypes), variables, that could explain pollinators' behavior (amount of nectar as the main reward, size and amount of pollen grains as a potentional reward). To find out how strong the triploid block is I analyzed ploidy of seeds and seedlings from mixed-ploidy population. The habitat isolation showed up to be the strongest reproductive barrier. Pollinator's behavior meaningfully contributes to isolation, phenology of flowering contributes only minimally. Index expressing rate of prereproductive barriers is 0,956. Pollinator Bombus pascuorum visited on one locality preferably tetraploid plants and Andrena sp. preferred diploid plants. Even though tetraploid plants produce more nectar, no other analysis showed pollinators' preference to tetraploid plants. I prepared one squash of diploid V. cracca using method of in situ hybridization. This method needs to be optimilized for the studied taxon.
16	GERMPLASM COLLECTION, CHARACTERIZATION, AND ENHANCEMENT OF EASTERN <i>PHLOX</i> SPECIES Zale, Peter J. January 2014 (has links) No description available. Horticulture Germplasm Accession Genome Size Flow Cytometry Chromosome Number Diploid Tetraploid Aneuploid Interploid Phylogeny Interspecific Hybridization Plant Breeding Recurrent Parent Partial Diallel Microsatellite Marker
17	Plant breeding aspects of ryegrasses (Lolium sp.) infected with endophytic fungi Stewart, Alan V. January 1987 (has links) Some aspects of the presence of systemic endophytic fungi in agriculturally important New Zealand grasses were studied in relation to plant breeding. Seedling resistance to adult Argentine stem weevil feeding in perennial ryegrass, Italian ryegrass and tall fescue was found to be related to the presence of their respective Acremonium endophytes in the seed rather than to plant genetic resistance. In addition a study of perennial ryegrass revealed that this resistance was independent of endophyte viability. The seedling resistance conferred by the endophyte of Italian ryegrass was found to be beneficial for field establishment. This endophyte differs from that in perennial ryegrass and tall fescue in that it does not confer resistance to Argentine stem weevil on mature plants, but only on seedlings. The extent of plant genetic seedling tolerance to adult Argentine stem weevil feeding was limited to broad inter-specific differences, with tall fescue more tolerant than perennial ryegrass and both of these more tolerant than Italian ryegrass. This ranking corresponds with previous observations on feeding preference on mature plants. A study of factors affecting the concentration of endophyte mycelia in infected seed of perennial ryegrass revealed that plant genetic factors had little effect. The major factors studied were: 1) the endophyte concentration in the maternal parent plant directly influenced the endophyte concentration in the seed. 2) nitrogen fertilizer applications to a seed crop reduced the concentration of mycelia in the seed, with earlier applications having a greater effect. 3) application of the fungicide propiconazole (Tilt) to a seed crop reduced the endophyte concentration in the seed. 4) the endophyte concentration in the seed was found to directly influence the endophyte concentration in seedlings, six month old plants and that of seed harvested from a first year seed crop. As there have been no previous reports of tetraploid perennial ryegrass cultivars with endophyte an experiment was conducted to determine if these could be developed by the standard procedure of colchicine treatment. The results revealed that endophyte was retained following colchicine treatment. ryegrass Lolium endophyte Acremonium seedling resistance nitrogen fungicide tetraploid Argentine stem weevil Listronotus
18	Diferenciace v polyploidním komplexu Libanotis pyrenaica (Apiaceae) / Differentiation in the polyploid complex Libanotis pyrenaica (Apiaceae) Přívozníková, Hana January 2016 (has links) Polyploidization belong to principal evolutionary mechanisms in plants. Although it is rather rare in the family Apiaceae, there are several interesting polyploid complexes here. The present study deals with Libanotis pyrenaica, species three previously reported ploidy levels, namely diploid (2n = 2x = 22), tetraploid (2n = 4 x = 44) and most likely very rare triploid (2n = 3x = 33). The present study aims at geographical pattern of ploidal diversity in central Europe, genetic variation and selected biological features of this species. Flow cytometru, analysis of two chloroplast DNA markers (trnF-trnL and cp018-cp020), morphometrics and in vitro germination experiments were used. The tetraploid cytotype occurs throughout the studied area; in the Czech Republic it was found in the České středohoří Mts., southern Bohemia and Moravia, in Slovakia it especially in the Carpathian mountains in western and central parts of the country and in the Pieniny Mts. in the northeast. Tetraploid cytotype occurs mainly in central-east Europe; in the Czech Republic it is common in the lowlands along the river of Labe and locally in Moravia; in Slovakia it was found along the river of Váh, in the Slovenské rudohorie Mts. and in the Belanské Tatry Mts. A mixed-ploidy population (2x, 4x) was discovered in southern...
19	Demography of Birch Populations across Scandinavia Sendrowski, Janek January 2022 (has links) Boreal forests are particularly vulnerable to climate change, experiencing a much more drastic increase in temperatures and having a limited amount of more northern refugia. The trees making up these vast and important ecosystems already had to adapt previously to environmental pressures brought about by the repeated glaciations during past ice ages. Studying the patterns of adaption of these trees can thus provide valuable insights on how to mitigate future damage. This thesis presents and analyses population structure, demo- graphic history and the distribution of fitness effects (DFE) of the diploid Betula pendula and tetraploid B. pubescens across Scandinavia. Birches–being widespread in boreal forests as well as having great economical importance–constitute superb model species. The analyses of this work confirm the expectations on postglacial population expansion and diploid-tetraploid introgression. They furthermore ascertain the presence of two genetic clusters and a remarkably similar DFE for the species. This work also contributes with a transparent, reproducible and reusable pipeline which facilitates running similar analyses for related species. birch betula pubescens pendula betula pubescens betula pendula silver birch downy birch demography population structure distribution of fitness effects DFE dadi UMAP PCA ADMIXTURE polyDFE ice age glaciation tree boreal forest climate change adaption tetraploid diploid-tetraploid introgression Scandinavia genetic cluster pipeline snakemake bioinformatics reproducible population genetics postglacial population expansion demographic history FEEMS site-frequency spectrum SFS last glacial maximum LGM workflow python population expansion population growth EST-SFS 0-fold degenerate 4-fold degenerate maximum likelihood estimation MLE variant call format VCF single-nucleotide polymorphism SNP Bioinformatics (Computational Biology) Bioinformatik (beräkningsbiologi)
20	Effects of alternative grass species on grazing preference of sheep for white clover Muraki, Tomohiro January 2008 (has links) Despite the importance of a high white clover (Trifolium repens) content in temperate pastoral systems in terms of livestock performance and nitrogen fixation, the proportion of white clover in grass-clover pastures is often low (<20%). This thesis examined in two experiments whether the white clover content of pastures could be improved by sowing white clover with alternative grass species to diploid perennial ryegrass (Lolium perenne L.). In a pasture experiment, DM production, pasture composition and morphology of grass-clover mixtures was measured over the establishment year (January 2007 to January 2008) where white clover was sown in fine mixtures with diploid perennial ryegrass, tetraploid perennial ryegrass, timothy (Phleum pratense L.) and cocksfoot (Dactylis glomerata L.). Pastures were irrigated and rotationally grazed with on-off grazing with Coopworth ewe hoggets. Total annual DM production of pasture was more than 20% higher in tetraploid (12521 kg DM ha⁻¹) and diploid (11733 kg DM ha⁻¹) perennial ryegrass than timothy (9751 kg DM ha⁻¹) and cocksfoot (9654 kg DM ha⁻¹). However, timothy (5936 kg DM ha⁻¹) and cocksfoot (5311 kg DM ha⁻¹) had more than four times higher white clover annual DM production than tetraploid (1310 kg DM ha⁻¹) and diploid (818 kg DM ha⁻¹) ryegrass. Pasture growth rate at the first three harvests in autumn was significantly greater in tetraploid and diploid ryegrass than timothy and cocksfoot. Timothy and cocksfoot had a higher proportion of white clover than tetraploid and diploid perennial ryegrass throughout the entire year. This was due to more and larger white clover plants in timothy and cocksfoot plots. In a grazing preference experiment, the partial preference of sheep for white clover offered in combination with the same grass species as in the pasture experiment was measured in five grazing tests in May, September, October, November and December 2007. Pastures were sown in January 2007. Paired plots (grass and clover both 4.2 m x 10 m) were grazed by three Coopworth ewe hoggets between 9am and 5pm, and preference was recorded by decline in pasture mass and visual scan sampling for grazing time. Grazing preference for clover was generally low throughout these tests (e.g. average apparent DM intake from clover = 47%; average grazing time from clover = 44%). Several explanations are proposed for this low preference including a high N content and intake rate of the grass relative to the clover. No significant differences were found among the grass treatments in total grass grazing time, total clover grazing time, ruminating time, the proportion of grazing time on clover, selective coefficient for clover and DM intake percentage from clover at any date. There was no significant change in overall sward surface height (SSH) decline among grass treatments throughout all the tests except December 2007 when the overall SSH decline for cocksfoot was significantly lower than the other species. The study indicated that the rapid growth rate of perennial ryegrass in the early phase of pasture establishment, rather than differences in partial preference, was the key factor limiting white clover content in the mixed swards relative to cocksfoot and timothy pastures. It is concluded that high clover-containing pastures capable of delivering high per head performance can be established through the use of slow establishing pasture species such as timothy and cocksfoot. white clover cocksfoot ryegrass timothy grazing preference tetraploid perennial ryegrass diploid perennial ryegrass Lolium perenne Phleum pratense Dactylis glomerata Trifolium repens mixed swards monocultures growth rate

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