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Registro Completo |
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Biblioteca(s): |
Embrapa Milho e Sorgo. |
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Data corrente: |
02/04/2002 |
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Data da última atualização: |
19/10/2023 |
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Autoria: |
GUIMARAES, P. E. de O. |
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Afiliação: |
PAULO EVARISTO DE O GUIMARAES, CNPMS. |
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Título: |
Effects of a long-term recurrent selection program on the genetic structure of the BSSS maize population. |
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Ano de publicação: |
2001 |
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Fonte/Imprenta: |
2001. |
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Páginas: |
99 p. |
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Idioma: |
Inglês |
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Notas: |
Tese (Doutorado) - Iowa State University, Ames. |
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Conteúdo: |
Evaluating of Recurrent Selection (RS) programs can lead to increase knowledge of methods, populations, and traits and give support for better management of breeding programs. The objective herein was to evaluate the effects of seven cycles of half-sib selection followed by seven cycles of S2 selection on the genetic structure of BSSS maize population. Individuals from BSSSP (progenitor lines), BS13(S)CO (original S2 selection), and BS13(S)C7 (7th S2 cycle) cycles were genotyped based on a sample of 105 RFLP loci. Measures of genetic variation within (expected heterozygosity, number of allelles, average frequency of the most common allele, and proportion of polymorphic loci) and among (Principal Component Analysis and Nei's genetic distance, NGD) cycles of selection indicated BSSSP has a considerable genetic variability, substantial loss a variation and increase of divergence over the cycles of selection, greatest loss of diversity occurred during the HS selection program, future cycles of RS are predicted to have narrow genetic variation, and low average effective population size was an important factor in loss of genetic variation. Changes in allele frequencies for about 30% of the loci cannot be explained by genetic drift alone, suggesting that selection also was an important factor of variation. The majority of loci in C0 and C7 were in H-W equilibrium. Progenitor lines Illinois Hy had a lower NGD to C0 and C7 and five of its unique had frequencies significantly increased in later generations, indicating a selective advantage over the cycles of RS. Hybrid Hy x LE 23 showed the lowest NGD to C0 and C7 populations. NGD among parental lines was not a good predictor of single-crosses yield performance. A founder effect observed herein may explain partially reduced genetic gains during the S2-selection period reported in other studies. Limited RFLP diversity in BS13(S)C7 suggests this population may not have enough genetic variability to sustain significant long-term genetic gains per se for grain yield. RFLP data were useful tools to evaluate this RS program. However, much more information could be obtained about recurrent selection programs by integrating of molecular (a standard set of marker loci) and phenotypic data. MenosEvaluating of Recurrent Selection (RS) programs can lead to increase knowledge of methods, populations, and traits and give support for better management of breeding programs. The objective herein was to evaluate the effects of seven cycles of half-sib selection followed by seven cycles of S2 selection on the genetic structure of BSSS maize population. Individuals from BSSSP (progenitor lines), BS13(S)CO (original S2 selection), and BS13(S)C7 (7th S2 cycle) cycles were genotyped based on a sample of 105 RFLP loci. Measures of genetic variation within (expected heterozygosity, number of allelles, average frequency of the most common allele, and proportion of polymorphic loci) and among (Principal Component Analysis and Nei's genetic distance, NGD) cycles of selection indicated BSSSP has a considerable genetic variability, substantial loss a variation and increase of divergence over the cycles of selection, greatest loss of diversity occurred during the HS selection program, future cycles of RS are predicted to have narrow genetic variation, and low average effective population size was an important factor in loss of genetic variation. Changes in allele frequencies for about 30% of the loci cannot be explained by genetic drift alone, suggesting that selection also was an important factor of variation. The majority of loci in C0 and C7 were in H-W equilibrium. Progenitor lines Illinois Hy had a lower NGD to C0 and C7 and five of its unique had frequencies significantly increase... Mostrar Tudo |
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Palavras-Chave: |
Maize. |
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Thesagro: |
Melhoramento; Milho; Zea Mays. |
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Thesaurus Nal: |
breeding. |
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Categoria do assunto: |
-- |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/90316/1/T-Paulo-Evaristo.pdf
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Marc: |
LEADER 02820nam a2200193 a 4500
001 1485209
005 2023-10-19
008 2001 bl uuuu m 00u1 u #d
100 1 $aGUIMARAES, P. E. de O.
245 $aEffects of a long-term recurrent selection program on the genetic structure of the BSSS maize population.$h[electronic resource]
260 $a2001.$c2001
300 $a99 p.
500 $aTese (Doutorado) - Iowa State University, Ames.
520 $aEvaluating of Recurrent Selection (RS) programs can lead to increase knowledge of methods, populations, and traits and give support for better management of breeding programs. The objective herein was to evaluate the effects of seven cycles of half-sib selection followed by seven cycles of S2 selection on the genetic structure of BSSS maize population. Individuals from BSSSP (progenitor lines), BS13(S)CO (original S2 selection), and BS13(S)C7 (7th S2 cycle) cycles were genotyped based on a sample of 105 RFLP loci. Measures of genetic variation within (expected heterozygosity, number of allelles, average frequency of the most common allele, and proportion of polymorphic loci) and among (Principal Component Analysis and Nei's genetic distance, NGD) cycles of selection indicated BSSSP has a considerable genetic variability, substantial loss a variation and increase of divergence over the cycles of selection, greatest loss of diversity occurred during the HS selection program, future cycles of RS are predicted to have narrow genetic variation, and low average effective population size was an important factor in loss of genetic variation. Changes in allele frequencies for about 30% of the loci cannot be explained by genetic drift alone, suggesting that selection also was an important factor of variation. The majority of loci in C0 and C7 were in H-W equilibrium. Progenitor lines Illinois Hy had a lower NGD to C0 and C7 and five of its unique had frequencies significantly increased in later generations, indicating a selective advantage over the cycles of RS. Hybrid Hy x LE 23 showed the lowest NGD to C0 and C7 populations. NGD among parental lines was not a good predictor of single-crosses yield performance. A founder effect observed herein may explain partially reduced genetic gains during the S2-selection period reported in other studies. Limited RFLP diversity in BS13(S)C7 suggests this population may not have enough genetic variability to sustain significant long-term genetic gains per se for grain yield. RFLP data were useful tools to evaluate this RS program. However, much more information could be obtained about recurrent selection programs by integrating of molecular (a standard set of marker loci) and phenotypic data.
650 $abreeding
650 $aMelhoramento
650 $aMilho
650 $aZea Mays
653 $aMaize
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Registro original: |
Embrapa Milho e Sorgo (CNPMS) |
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Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
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Registro Completo
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Biblioteca(s): |
Embrapa Milho e Sorgo. |
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Data corrente: |
04/11/2020 |
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Data da última atualização: |
04/11/2020 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 2 |
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Autoria: |
RIBEIRO, R. da S.; PASSOS, A. M. A. dos; AKER, A. M. |
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Afiliação: |
Rodrigo da S. Ribeiro, Universidade Federal de Rondônia; ALEXANDRE MARTINS ABDAO DOS PASSOS, CNPMS; Andreia M. Aker, Universidade Federal dos Vales do Jequitinhonha e Mucuri. |
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Título: |
Agronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome. |
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Ano de publicação: |
2020 |
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Fonte/Imprenta: |
Revista Brasileira de Engenharia Agrícola e Ambiental, v. 24, n. 12, p. 793-799, 2020. |
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DOI: |
http://dx.doi.org/10.1590/1807-1929/agriambi.v24n12p793-799 |
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Idioma: |
Inglês |
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Conteúdo: |
Soybean is an alternative crop to be used in intensified land use systems and recovery of degraded areas in Brazil. Thus, the objective of this study was to evaluate the agronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome. Soybean crop was grown in alleys with widths of 18, 30, and 42 m between the 4-row tree sets of eucalyptus and evaluated in two agricultural years (2016-2017 and 2017-2018). Plant height, first pod insertion height, number of grains per pod, number of pods per plant, 100-grain weight, and grain yield of soybean plants at maturation stage were evaluated in different distances from the eucalyptus (10, 20, 30 and 45% of the alley width). The lowest mean grain yield was found for the alley of 18 m in the 2017-2018 agricultural year. The proximity of soybean plants to eucalyptus trees affects negatively the grain yield, plant height, first pod insertion height, plant population, and number of pods per plant. The crop-livestock-forest integration system, with the forest component consisting of 5-year-old eucalyptus trees (technical age for harvest), resulted in higher soybean grain yields for the alley of 42 m. The growth of soybean crops in alleys of 18 m between 4-row tree sets of 5-year-old eucalyptus trees is not recommended for the Southwestern region of the Brazilian Amazon biome. |
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Palavras-Chave: |
Integração lavoura-pecuária-floresta; Intensificação ecológica; Produção sustentável. |
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Thesagro: |
Sistema de Produção; Soja. |
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Categoria do assunto: |
F Plantas e Produtos de Origem Vegetal |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/217449/1/Agronomic-performance.pdf
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Marc: |
LEADER 02187naa a2200217 a 4500
001 2126277
005 2020-11-04
008 2020 bl uuuu u00u1 u #d
024 7 $ahttp://dx.doi.org/10.1590/1807-1929/agriambi.v24n12p793-799$2DOI
100 1 $aRIBEIRO, R. da S.
245 $aAgronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome.$h[electronic resource]
260 $c2020
520 $aSoybean is an alternative crop to be used in intensified land use systems and recovery of degraded areas in Brazil. Thus, the objective of this study was to evaluate the agronomic performance of soybean crops under integrated production systems in the Southwestern Brazilian Amazon biome. Soybean crop was grown in alleys with widths of 18, 30, and 42 m between the 4-row tree sets of eucalyptus and evaluated in two agricultural years (2016-2017 and 2017-2018). Plant height, first pod insertion height, number of grains per pod, number of pods per plant, 100-grain weight, and grain yield of soybean plants at maturation stage were evaluated in different distances from the eucalyptus (10, 20, 30 and 45% of the alley width). The lowest mean grain yield was found for the alley of 18 m in the 2017-2018 agricultural year. The proximity of soybean plants to eucalyptus trees affects negatively the grain yield, plant height, first pod insertion height, plant population, and number of pods per plant. The crop-livestock-forest integration system, with the forest component consisting of 5-year-old eucalyptus trees (technical age for harvest), resulted in higher soybean grain yields for the alley of 42 m. The growth of soybean crops in alleys of 18 m between 4-row tree sets of 5-year-old eucalyptus trees is not recommended for the Southwestern region of the Brazilian Amazon biome.
650 $aSistema de Produção
650 $aSoja
653 $aIntegração lavoura-pecuária-floresta
653 $aIntensificação ecológica
653 $aProdução sustentável
700 1 $aPASSOS, A. M. A. dos
700 1 $aAKER, A. M.
773 $tRevista Brasileira de Engenharia Agrícola e Ambiental$gv. 24, n. 12, p. 793-799, 2020.
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Embrapa Milho e Sorgo (CNPMS) |
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