Repetibilidade e seleção em Panicum maximum Jacq.

Detalhes bibliográficos
Autor(a) principal: Martuscello, Janaina Azevedo
Data de Publicação: 2007
Tipo de documento: Tese
Idioma: por
Título da fonte: LOCUS Repositório Institucional da UFV
Texto Completo: http://locus.ufv.br/handle/123456789/1911
Resumo: The experiment was done with the objective to evaluate the repeatability coefficient of some agronomic characteristics in hybrids of Panicum maximum, and to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. It was also proposed to compare selection strategies between and within families, combined selection, mass selection and stratified mass selection. For this, ten plots of sexual plants were randomly distributed among 230 plots of apomictic accessions. After natural pollination, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female progenitor were evaluated in a random blocks design experiment, with five plants per plot and six replications (for the repeatability estimate) and five replications (to evaluate the genetic parameters). The coefficient of repeatability, based on five evaluation harvests, was estimated by the methods of Analysis of Variance, Principal Components (correlation and covariance matrices) and Structural Analysis. For the evaluation of genetic parameters, five evaluation harvests were done in the rainy seasons and two in the dry seasons in all plants. Immediately after the harvests, the forage was weighed to obtain green matter production. Samples were separated into leaf blades, stems + sheath and dead matter, which were air-forced dried and later weighed for the determination of dry matter and percentages of leaves, stems and dead matter of each genotype. The estimates of the repeatability coefficient by the different methods, for all evaluated characteristics varied from 0,51 to 0,86 and may be considered high, as were the determination coefficients. It was observed that the repeatability coefficients obtained for the four characteristics evaluated by the method of analysis of variance, were almost always smaller than the estimates from the other methods. By the principal components method (based on the covariance matrix) the estimates were always greater than from the other methods. Considering as satisfactory a level of 80 or 90% confidence (R2) for the decision on the relative superiority of the hybrids, for all the evaluated characteristics, the five harvests were sufficient for the choice of the best plant. The exclusion of harvests 1 and 2 promoted an increase in the coefficients of repeatability and determination. There was significant genetic variability for all the production characteristics, with the exception of dead matter both in the rainy and the dry periods, which shows the possibility of considerable gains with selection. The selection criteria used (selection between and within families, combined, mass and stratified mass selections) were efficient for application in P. maximum breeding, with medium to high gains for most characteristics evaluated. The highest genetic gains were obtained from combined selection. However, mass and stratified mass selections promoted high genetic gains and may be used in P. maximum breeding. The sexual progenitors identified as numbers 7, 1, 3 and 5 are promising and may be used in future crosses, as well as for increase of the genetic variability in the P.maximum genebank.
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spelling Martuscello, Janaina Azevedohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4771005T8Jank, Lianahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781975Y3Cruz, Cosme Damiãohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788274A6Fonseca, Dilermando Miranda dahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780539D6Queiroz, Augusto César dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783006P5Reis, Múcio Silvahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783370J42015-03-26T12:55:05Z2007-12-132015-03-26T12:55:05Z2007-09-28MARTUSCELLO, Janaina Azevedo. Repeatability and selection of Panicum maximum Jacq.. 2007. 111 f. Tese (Doutorado em Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul) - Universidade Federal de Viçosa, Viçosa, 2007.http://locus.ufv.br/handle/123456789/1911The experiment was done with the objective to evaluate the repeatability coefficient of some agronomic characteristics in hybrids of Panicum maximum, and to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. It was also proposed to compare selection strategies between and within families, combined selection, mass selection and stratified mass selection. For this, ten plots of sexual plants were randomly distributed among 230 plots of apomictic accessions. After natural pollination, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female progenitor were evaluated in a random blocks design experiment, with five plants per plot and six replications (for the repeatability estimate) and five replications (to evaluate the genetic parameters). The coefficient of repeatability, based on five evaluation harvests, was estimated by the methods of Analysis of Variance, Principal Components (correlation and covariance matrices) and Structural Analysis. For the evaluation of genetic parameters, five evaluation harvests were done in the rainy seasons and two in the dry seasons in all plants. Immediately after the harvests, the forage was weighed to obtain green matter production. Samples were separated into leaf blades, stems + sheath and dead matter, which were air-forced dried and later weighed for the determination of dry matter and percentages of leaves, stems and dead matter of each genotype. The estimates of the repeatability coefficient by the different methods, for all evaluated characteristics varied from 0,51 to 0,86 and may be considered high, as were the determination coefficients. It was observed that the repeatability coefficients obtained for the four characteristics evaluated by the method of analysis of variance, were almost always smaller than the estimates from the other methods. By the principal components method (based on the covariance matrix) the estimates were always greater than from the other methods. Considering as satisfactory a level of 80 or 90% confidence (R2) for the decision on the relative superiority of the hybrids, for all the evaluated characteristics, the five harvests were sufficient for the choice of the best plant. The exclusion of harvests 1 and 2 promoted an increase in the coefficients of repeatability and determination. There was significant genetic variability for all the production characteristics, with the exception of dead matter both in the rainy and the dry periods, which shows the possibility of considerable gains with selection. The selection criteria used (selection between and within families, combined, mass and stratified mass selections) were efficient for application in P. maximum breeding, with medium to high gains for most characteristics evaluated. The highest genetic gains were obtained from combined selection. However, mass and stratified mass selections promoted high genetic gains and may be used in P. maximum breeding. The sexual progenitors identified as numbers 7, 1, 3 and 5 are promising and may be used in future crosses, as well as for increase of the genetic variability in the P.maximum genebank.O experimento foi conduzido objetivando avaliar o coeficiente de repetibilidade de algumas características agronômicas em híbridos de Panicum maximum, bem como selecionar genótipos superiores em população de meio irmãos, originárias a partir do cruzamento de plantas apomíticas com plantas sexuais. Prepôs-se também comparar estratégias de seleção entre e dentro de famílias, seleção combinada, seleção massal e seleção massal estratificada. Para isto, dez parcelas de plantas sexuais da espécie foram aleatoriamente distribuídos entre 230 parcelas de acessos apomíticos. Após a fecundação natural, sementes de cada planta sexual constituiu-se em uma família de meio irmãos. Trinta plantas de cada progenitora foram avaliadas em delineamento de blocos ao acaso, com cinco plantas por parcela e seis repetições (para estimativa de repetibilidade) e cinco repetições (para avaliação de parâmetros genéticos). A partir de cinco cortes, estimou-se o coeficiente de repetibilidade pelos métodos da Análise de variância, Componentes principais (matriz de correlação e covariância) e Análise estrutural. Para avaliação dos parâmetros genéticos foram realizados cinco cortes no período das águas e dois no período da seca em todas as plantas. Imediatamente após os cortes, a forragem foi pesada para obtenção da produção de matéria verde. Amostras do material foram separadas em lâmina, colmo + bainha e material morto, e levados a estufa para secagem e posterior determinação da produção de matéria seca total e matéria seca foliar, porcentagem de folhas, porcentagem de colmo e porcentagem de material morto em cada genótipo. As estimativas do coeficiente de repetibilidade nos diferentes métodos, para todas as características avaliadas variaram entre 0,51 e 0,86 e podem ser considerados altos, assim como os coeficientes de determinação. Observou-se que as estimativas do coeficiente de repetibilidade, obtidas para as quatro características avaliadas pelo método da análise de variância, foram quase sempre menores que as estimativas pelos demais métodos. Pelo método dos componentes principais (baseado na matriz de covariância) as estimativas foram sempre maiores em relação aos demais métodos. Considerando-se como satisfatório um nível de 80 ou 90% de confiabilidade (R2) para tomada de decisão sobre a superioridade relativa dos híbridos, para todas as características avaliadas, as cinco medições realizadas foram suficientes para escolha da melhor planta. A exclusão dos cortes 1 e 2 promoveu aumento nos coeficientes de repetibilidade e determinação. Houve variabilidade genética significativa para todas as características de produção, à exceção da variável material morto tanto para o período das águas, quanto para o período da seca, evidenciando a possibilidade de ganhos consideráveis com a seleção. Os critérios de seleção utilizados (seleção entre e dentro de famílias, seleção combinada, seleção massal e massal estratificada) mostram-se eficientes para aplicação no melhoramento de P. maximum, com ganhos considerados de médio a altos para a maioria das características avaliadas. Os maiores ganhos genéticos foram proporcionados pela seleção combinada. Entretanto, as seleções massal e massal estratificada promoveram ganhos genéticos altos e podem ser utilizados no melhoramento de P. maximum. As famílias identificadas pela numeração 7, 1, 3 e 5 são promissoras e podem ser utilizadas para futuros cruzamentos, bem como para aumento da variabilidade genética no banco de germoplasma de P.maximum.Conselho Nacional de Desenvolvimento Científico e Tecnológicoapplication/pdfporUniversidade Federal de ViçosaDoutorado em ZootecniaUFVBRGenética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e ForragiculForrageiras tropicaisMelhoramento genéticoTropical forrage cropsBreedingCNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURARepetibilidade e seleção em Panicum maximum Jacq.Repeatability and selection of Panicum maximum Jacq.info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/openAccessreponame:LOCUS Repositório Institucional da UFVinstname:Universidade Federal de Viçosa (UFV)instacron:UFVORIGINALtexto completo.pdfapplication/pdf871337https://locus.ufv.br//bitstream/123456789/1911/1/texto%20completo.pdfa468ea665c8ba2313f7a2c3c2f316381MD51TEXTtexto completo.pdf.txttexto completo.pdf.txtExtracted texttext/plain188049https://locus.ufv.br//bitstream/123456789/1911/2/texto%20completo.pdf.txt6feba4a3e37c3e9521f66ed481e78858MD52THUMBNAILtexto completo.pdf.jpgtexto completo.pdf.jpgIM Thumbnailimage/jpeg3449https://locus.ufv.br//bitstream/123456789/1911/3/texto%20completo.pdf.jpg9c2e6b1a52f40d6a7595fd9358fbc2e1MD53123456789/19112016-04-07 23:17:23.136oai:locus.ufv.br:123456789/1911Repositório InstitucionalPUBhttps://www.locus.ufv.br/oai/requestfabiojreis@ufv.bropendoar:21452016-04-08T02:17:23LOCUS Repositório Institucional da UFV - Universidade Federal de Viçosa (UFV)false
dc.title.por.fl_str_mv Repetibilidade e seleção em Panicum maximum Jacq.
dc.title.alternative.eng.fl_str_mv Repeatability and selection of Panicum maximum Jacq.
title Repetibilidade e seleção em Panicum maximum Jacq.
spellingShingle Repetibilidade e seleção em Panicum maximum Jacq.
Martuscello, Janaina Azevedo
Forrageiras tropicais
Melhoramento genético
Tropical forrage crops
Breeding
CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA
title_short Repetibilidade e seleção em Panicum maximum Jacq.
title_full Repetibilidade e seleção em Panicum maximum Jacq.
title_fullStr Repetibilidade e seleção em Panicum maximum Jacq.
title_full_unstemmed Repetibilidade e seleção em Panicum maximum Jacq.
title_sort Repetibilidade e seleção em Panicum maximum Jacq.
author Martuscello, Janaina Azevedo
author_facet Martuscello, Janaina Azevedo
author_role author
dc.contributor.authorLattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4771005T8
dc.contributor.author.fl_str_mv Martuscello, Janaina Azevedo
dc.contributor.advisor-co1.fl_str_mv Jank, Liana
dc.contributor.advisor-co1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781975Y3
dc.contributor.advisor-co2.fl_str_mv Cruz, Cosme Damião
dc.contributor.advisor-co2Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788274A6
dc.contributor.advisor1.fl_str_mv Fonseca, Dilermando Miranda da
dc.contributor.advisor1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4780539D6
dc.contributor.referee1.fl_str_mv Queiroz, Augusto César de
dc.contributor.referee1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783006P5
dc.contributor.referee2.fl_str_mv Reis, Múcio Silva
dc.contributor.referee2Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783370J4
contributor_str_mv Jank, Liana
Cruz, Cosme Damião
Fonseca, Dilermando Miranda da
Queiroz, Augusto César de
Reis, Múcio Silva
dc.subject.por.fl_str_mv Forrageiras tropicais
Melhoramento genético
topic Forrageiras tropicais
Melhoramento genético
Tropical forrage crops
Breeding
CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA
dc.subject.eng.fl_str_mv Tropical forrage crops
Breeding
dc.subject.cnpq.fl_str_mv CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA
description The experiment was done with the objective to evaluate the repeatability coefficient of some agronomic characteristics in hybrids of Panicum maximum, and to select superior genotypes in half-sib populations obtained from crosses between sexual plants and apomictic accessions. It was also proposed to compare selection strategies between and within families, combined selection, mass selection and stratified mass selection. For this, ten plots of sexual plants were randomly distributed among 230 plots of apomictic accessions. After natural pollination, seeds of each sexual plant constituted a half-sib family. Thirty plants of each female progenitor were evaluated in a random blocks design experiment, with five plants per plot and six replications (for the repeatability estimate) and five replications (to evaluate the genetic parameters). The coefficient of repeatability, based on five evaluation harvests, was estimated by the methods of Analysis of Variance, Principal Components (correlation and covariance matrices) and Structural Analysis. For the evaluation of genetic parameters, five evaluation harvests were done in the rainy seasons and two in the dry seasons in all plants. Immediately after the harvests, the forage was weighed to obtain green matter production. Samples were separated into leaf blades, stems + sheath and dead matter, which were air-forced dried and later weighed for the determination of dry matter and percentages of leaves, stems and dead matter of each genotype. The estimates of the repeatability coefficient by the different methods, for all evaluated characteristics varied from 0,51 to 0,86 and may be considered high, as were the determination coefficients. It was observed that the repeatability coefficients obtained for the four characteristics evaluated by the method of analysis of variance, were almost always smaller than the estimates from the other methods. By the principal components method (based on the covariance matrix) the estimates were always greater than from the other methods. Considering as satisfactory a level of 80 or 90% confidence (R2) for the decision on the relative superiority of the hybrids, for all the evaluated characteristics, the five harvests were sufficient for the choice of the best plant. The exclusion of harvests 1 and 2 promoted an increase in the coefficients of repeatability and determination. There was significant genetic variability for all the production characteristics, with the exception of dead matter both in the rainy and the dry periods, which shows the possibility of considerable gains with selection. The selection criteria used (selection between and within families, combined, mass and stratified mass selections) were efficient for application in P. maximum breeding, with medium to high gains for most characteristics evaluated. The highest genetic gains were obtained from combined selection. However, mass and stratified mass selections promoted high genetic gains and may be used in P. maximum breeding. The sexual progenitors identified as numbers 7, 1, 3 and 5 are promising and may be used in future crosses, as well as for increase of the genetic variability in the P.maximum genebank.
publishDate 2007
dc.date.available.fl_str_mv 2007-12-13
2015-03-26T12:55:05Z
dc.date.issued.fl_str_mv 2007-09-28
dc.date.accessioned.fl_str_mv 2015-03-26T12:55:05Z
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dc.identifier.uri.fl_str_mv http://locus.ufv.br/handle/123456789/1911
identifier_str_mv MARTUSCELLO, Janaina Azevedo. Repeatability and selection of Panicum maximum Jacq.. 2007. 111 f. Tese (Doutorado em Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul) - Universidade Federal de Viçosa, Viçosa, 2007.
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