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| Registros recuperados: 107 | |
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| Dunham, Jason; University of Nevada-Reno; jdunham@proaxis.com; Peacock, Mary; University of Nevada-Reno; mpeacock@scs.unr.edu; Tracy, C. Richard; University of Nevada-Reno; dtracy@unr.edu; Nielsen, Jennifer; Stanford University; jnielsen@leland.stanford.edu; Vinyard, Gary; University of Nevada-Reno; gvinyard@med.unr.edu. |
| Risks of population extinction have been estimated using a variety of methods incorporating information from different spatial and temporal scales. We briefly consider how several broad classes of extinction risk assessments, including population viability analysis, incidence functions, and ranking methods integrate information on different temporal and spatial scales. In many circumstances, data from surveys of neutral genetic variability within, and among, populations can provide information useful for assessing extinction risk. Patterns of genetic variability resulting from past and present ecological and demographic events, can indicate risks of extinction that are otherwise difficult to infer from ecological and demographic analyses alone. We provide... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Extinction risk; Genetic variation; Incidence function analysis; Population viability analysis; Ranking methods; Risk assessment; Spatial scale; Temporal scale.. |
| Ano: 1999 |
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| Veasey,Elisabeth Ann; Negrão,Marta Organo; Martins,Paulo Sodero; Bandel,Gerhard. |
| The objective of this study was to characterize 17 accessions of Sesbania, representing S. exasperata, S. grandiflora, S. sesban, S. tetraptera and S. virgata at the seedling stage, and to evaluate the initial development during the first two months after planting. The trial was conducted in a greenhouse in a randomized block design, with 4 replications and 5 plants per plot. The traits recorded were: plant height (PH), from four observations at 15-day intervals, at 17, 32, 47 and 62 days after planting; length of hypocotyl (LH) and epicotyl (LEP); length (LE1) and width (WE1) of the first eophyll; and number of leaflet pairs of the second metaphyll (NLP), evaluated 17 days after planting. Univariate analyses of variance were performed, estimating the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sesbania; Seedling morphology; Genetic variation; Early growth. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161999000200011 |
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| Rocha,Beatriz Helena Gomes; Augustin,Eliane; Silva,João Baptista da; Viégas,Judith. |
| Two species of wild potato Solanum commersonii, subspecies commersonii and malmeanum, and S. chacoense, subspecies muelleri occur in southern Brazil. Their rusticity and easy adaptation to extreme climatic conditions make them valuable for breeding programs. The objective of this work was to analyze the isoenzymatic variability of 113 clones of wild potato subspecies. They were collected and maintained at Embrapa-Centro de Pesquisa Agropecuária de Clima Temperado, at Pelotas, RS, Brazil. Enzymes involved in energetic (group I) or in peripherical (group II) metabolism constituted the material used. Polyacrylamide horizontal gel electrophoresis was used to analyze peroxidase, aspartate transaminase, phosphoglucomutase and isocitrate dehydrogenase isoenzymes.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Peroxidases; Aminotransferases; Isomerases; Isocitrate dehydrogenase; Genetic variation. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2001000500008 |
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| KARIA, C. T.; ANDRADE, R. P. de; CHARCHAR, M. J. D'Á.; GOMES, A. C.. |
| Resumo: A introdução de populações heterogêneas e a sua caracterização é o primeiro passo para um programa de seleção e/ou melhoramento genético de plantas. A heterogeneidade permite a seleção de indivíduos superiores que podem ser diretamente liberados como cultivares ou servir como fonte de genes em programas de melhoramento genético. A flora nativa da Região é extremamente rica em leguminosas, sendo, inclusive, centro de origem de diversas espécies que poderiam ser usadas como forrageiras. Dentre as leguminosas nativas, destaca-se o gênero Stylosanthes que possui diversas espécies, amplamente, distribuídas pelo continente americano, apresentando grande variação de formas e tipos, resultante da evolução de populações submetidas às diferentes condições de... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Stilosante; Feed legumes.; Cerrado; Germoplasma; Leguminosa Forrageira; Melhoramento Genético Vegetal; Morfologia Vegetal; Variação Genética.; Germplasm; Genetic variation; Plant anatomy; Plant breeding.. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567951 |
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| Vacaro,Elton; Barbosa Neto,José Fernandes; Pegoraro,Diego Girardi; Nuss,Claudio Natalino; Conceição,Leo Duc Haa. |
| Genetic progress depends on germplasm quality and breeding methods. Twelve maize populations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA) and specific (SCA) combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxerê, suggested the environmental influence on the manifestation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Germplasm; Heterosis; Genetic variation. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2002000100009 |
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| Pierrot-Bults, A.C.; Spoel, S. van der. |
| Pelagic species are widely distributed in a horizontal plane and have three-dimensional distributions, since the sea covers about 70% of the surface of the earth, and on average 4 km deep. For most macrozooplankton and micronekton groups there seems to be no great expectations of finding new taxa with the exception of gelatinous groups and of the deep sea, which is a relatively unknown especially in the benthopelagic zone close to the sea-bed. However, we do not know very much about variation, either morphological or genetical, within socalled species in different parts of their range. We think we are dealing with single very broadly distributed species, which, in reality, are species complexes consisting of several more or less cryptic species or... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Pelagic macrozooplankton/micronekton diversity; Biogeographic patterns; Genetic variation; Morphological variation; Cryptic species; 42.79. |
| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/220316 |
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| Registros recuperados: 107 | |
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