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 | Acesso ao texto completo restrito à biblioteca da Embrapa Caprinos e Ovinos. Para informações adicionais entre em contato com cnpc.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
13/11/2023 |
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Autoria: |
YOUNG, S. S. Y. |
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Título: |
A further examination of the relative efficiency of three methods of selection for genetic gains under lessrestricted conditions. |
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Ano de publicação: |
1961 |
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Fonte/Imprenta: |
Genetical Research, v. 2, n. 1, p. 106-121, Feb. 1961. |
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DOI: |
https://doi.org/10.1017/S0016672300000598 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: The relative efficiency of three methods of selection (index, independent culling levels and tandem) is compared in terms of genetic gains in economic units. The comparison covers cases where variances, heritabilities and economic weights are unequal, while the case of two correlated characters is also examined. Various factors may influence the relative efficiency, including selection intensity, the number of traits under selection, the relative importance of those traits (in terms of a factor ?, which is the product of economic weight, heritability and phenotypic standard deviation), and the correlations between them. The conclusions are: (i) In all circumstances the index is never less efficient than independent culling levels, though in some cases it is no more efficient. Independent culling is, in turn, never less, but in some cases no more efficient than tandem selection. (ii) The superiority of the index over other methods increases with an increasing number of traits under selection, but decreases with increasing differences in relative importance, its superiority being at a maximum when the traits are of equal importance. The superiority of the index over independent culling levels decreases with increasing selection intensity, but its superiority over tandem selection is independent of intensity. (iii) The superiority of independent culling over tandem selection increases with increasing selection intensity or an increasing number of traits under selection, but decreases with increasing differences in relative importance. (iv) The relative efficiency of the index over other methods is much affected by the phenotypic correlation between traits when the traits are of equal importance, the relative efficiency of the index being higher when the phenotypic correlation is low or negative. The effect of genetic correlation is only apparent when the traits are of unequal importance and its influence on relative efficiency changes with changes in other parameters. (v) The relative efficiency of selection methods may be changed by their use for special purposes. MenosAbstract: The relative efficiency of three methods of selection (index, independent culling levels and tandem) is compared in terms of genetic gains in economic units. The comparison covers cases where variances, heritabilities and economic weights are unequal, while the case of two correlated characters is also examined. Various factors may influence the relative efficiency, including selection intensity, the number of traits under selection, the relative importance of those traits (in terms of a factor ?, which is the product of economic weight, heritability and phenotypic standard deviation), and the correlations between them. The conclusions are: (i) In all circumstances the index is never less efficient than independent culling levels, though in some cases it is no more efficient. Independent culling is, in turn, never less, but in some cases no more efficient than tandem selection. (ii) The superiority of the index over other methods increases with an increasing number of traits under selection, but decreases with increasing differences in relative importance, its superiority being at a maximum when the traits are of equal importance. The superiority of the index over independent culling levels decreases with increasing selection intensity, but its superiority over tandem selection is independent of intensity. (iii) The superiority of independent culling over tandem selection increases with increasing selection intensity or an increasing number of traits under selectio... Mostrar Tudo |
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Thesagro: |
Genética Animal; Melhoramento Genético Animal; Seleção Genética. |
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Thesaurus Nal: |
Animal genetics; Breeding and Genetic Improvement; Selection criteria. |
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Categoria do assunto: |
G Melhoramento Genético |
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Marc: |
LEADER 02834naa a2200205 a 4500
001 1521032
005 2023-11-13
008 1961 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1017/S0016672300000598$2DOI
100 1 $aYOUNG, S. S. Y.
245 $aA further examination of the relative efficiency of three methods of selection for genetic gains under lessrestricted conditions.$h[electronic resource]
260 $c1961
520 $aAbstract: The relative efficiency of three methods of selection (index, independent culling levels and tandem) is compared in terms of genetic gains in economic units. The comparison covers cases where variances, heritabilities and economic weights are unequal, while the case of two correlated characters is also examined. Various factors may influence the relative efficiency, including selection intensity, the number of traits under selection, the relative importance of those traits (in terms of a factor ?, which is the product of economic weight, heritability and phenotypic standard deviation), and the correlations between them. The conclusions are: (i) In all circumstances the index is never less efficient than independent culling levels, though in some cases it is no more efficient. Independent culling is, in turn, never less, but in some cases no more efficient than tandem selection. (ii) The superiority of the index over other methods increases with an increasing number of traits under selection, but decreases with increasing differences in relative importance, its superiority being at a maximum when the traits are of equal importance. The superiority of the index over independent culling levels decreases with increasing selection intensity, but its superiority over tandem selection is independent of intensity. (iii) The superiority of independent culling over tandem selection increases with increasing selection intensity or an increasing number of traits under selection, but decreases with increasing differences in relative importance. (iv) The relative efficiency of the index over other methods is much affected by the phenotypic correlation between traits when the traits are of equal importance, the relative efficiency of the index being higher when the phenotypic correlation is low or negative. The effect of genetic correlation is only apparent when the traits are of unequal importance and its influence on relative efficiency changes with changes in other parameters. (v) The relative efficiency of selection methods may be changed by their use for special purposes.
650 $aAnimal genetics
650 $aBreeding and Genetic Improvement
650 $aSelection criteria
650 $aGenética Animal
650 $aMelhoramento Genético Animal
650 $aSeleção Genética
773 $tGenetical Research$gv. 2, n. 1, p. 106-121, Feb. 1961.
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| 4. |  | ROCHA, S. M. B.; MENDES, L. W.; OLIVEIRA, L. M. de S.; MELO, V. M. M.; ANTUNES, J. E. L.; ARAÚJO, F. F.; HUNGRIA, M.; ARAÚJO, A. S. F. Nodule microbiome from cowpea and lima bean grown in composted tannery sludge-treated soil. Applied Soil Ecology, v. 151, 103542, 2020. 7 p.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Soja. |
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| 5. | | BARBOSA, L. M. de P.; SANTOS, T. P. da S.; SANTOS, T. O. da S.; OLIVEIRA, L. M. de S.; ALCANTARA NETO, F. de; ARAUJO, A. S. F. de; SOUZA, H. A. de; NUNES, L. A. P. L.; RODRIGUES, A. C.; SOUSA, R. S. de. The morphophysiological and yield characteristics of biquinho amarelo pepper in response to bovine rumen residue and chicken litter in soil are dose dependent. Journal of Plant Nutrition, 20 Jun 2024. Online.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 4 |
| Biblioteca(s): Embrapa Meio-Norte. |
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| 6. | | ALBUQUERQUE, T. M. de; MENDES, L. W.; ROCHA, S. M. B.; ANTUNES, J. E. L.; OLIVEIRA, L. M. de S.; MELO, V. M. M.; OLIVEIRA, F. A. S.; PEREIRA, A. P. de A.; SILVA, V. B. da; GOMES, R. L. F.; ALCANTARA NETO, F. de; LOPES, A. C. de A.; ROCHA, M. de M.; ARAUJO, A. S. F. Genetically related genotypes of cowpea present similar bacterial community in the rhizosphere. Scientific Reports, v. 12, 3472, 2022.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Meio-Norte. |
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| Registros recuperados : 6 | |
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