|
Registro Completo |
|
Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
|
Data corrente: |
01/08/1992 |
|
Data da última atualização: |
17/06/2025 |
|
Autoria: |
DICKERSON, G. E. |
|
Título: |
Implications of genetic-environmental interaction in animal breeding. |
|
Ano de publicação: |
1962 |
|
Fonte/Imprenta: |
Animal Production, v. 4, n. 1, p. 47-63, 1962. |
|
DOI: |
https://doi.org/10.1017/S0003356100034395 |
|
Idioma: |
Inglês |
|
Conteúdo: |
This report is an attempt to interpret evidence concerning geneticenvironmental interaction as it relates to the effectiveness of selection. Methods of estimating genetic-environmental interaction were investigated with the conclusion that the standard analysis of variance is a satisfactory tool provided (1) the interaction component of variance is adjusted for important variation between environments in the scale of genetic effects and (2) the variance component for the average effects of genetic groups is recognised as equivalent to the average covariance of the same genetic group in different environments (i.e. ) to include the real possibility of negative genetic correlation. It is shown that (1) response to selection for improved average performance over varying environments (ΔGt) is proportional to the genetic correlation between expressions of the same genotype in different environments (rG), that (2) gain in ΔGi, from measuring performance in k environments is proportional to if k times as many animals are tested, but to if total numbers per genotypic class (nk) are held constant, where g2 is heritability of individual variation within environments and rG is the correlation between the phenotypic expressions of the same genotype in different environments. Evidence is presented that (1) variations among poultry-farm environments in California cause important, but largely unpredictable, shifts in ranking of genetic stocks for egg production, and (2) improved accuracy in measuring genetic differences in average performance across environments probably justifies utilising a sample of 5 to 10 farms representing the range of environments for which the stock is bred. MenosThis report is an attempt to interpret evidence concerning geneticenvironmental interaction as it relates to the effectiveness of selection. Methods of estimating genetic-environmental interaction were investigated with the conclusion that the standard analysis of variance is a satisfactory tool provided (1) the interaction component of variance is adjusted for important variation between environments in the scale of genetic effects and (2) the variance component for the average effects of genetic groups is recognised as equivalent to the average covariance of the same genetic group in different environments (i.e. ) to include the real possibility of negative genetic correlation. It is shown that (1) response to selection for improved average performance over varying environments (ΔGt) is proportional to the genetic correlation between expressions of the same genotype in different environments (rG), that (2) gain in ΔGi, from measuring performance in k environments is proportional to if k times as many animals are tested, but to if total numbers per genotypic class (nk) are held constant, where g2 is heritability of individual variation within environments and rG is the correlation between the phenotypic expressions of the same genotype in different environments. Evidence is presented that (1) variations among poultry-farm environments in California cause important, but largely unpredictable, shifts in ranking of genetic stocks for egg production, and (2) improved accuracy i... Mostrar Tudo |
|
Palavras-Chave: |
Ambiente; Inteiracao ambiental; Interação genótipo ambiente; Interacoes; Melhoramento gentico. |
|
Thesagro: |
Genótipo. |
|
Thesaurus Nal: |
Animal breeding; Genotype-environment interaction. |
|
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
|
Marc: |
null
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
|
