Data/hora: 10/06/2024 08:20:36

Provedor de dados: | 63
País: | Brazil
Título: | Diallel analysis of maize resistance to Phaeosphaeria maydis
Autores: | Silva,Herberte Pereira da; Moro,José Roberto.
Data: | 2004-02-01
Ano: | 2004
Palavras-chave: | Zea mays L.; Genetic resistance; Heterotic effects; General and specific combining ability.
Resumo: | In breeding programs directed towards genetic resistance against diseases, the estimation of genetic parameters that control resistance allows the introduction of resistance into suscetible germplasm to be clearly focused. The purposes of this study were to estimate heterosis effects, and the general (GCA) and specific (SCA) combining abilities by using two rating methods for resistance to Phaeosphaeria maydis in a diallel analysis of 36 F1 maize hybrids and their nine inbred lines. Trials were conducted in three environments. Disease severity was evaluated in the whole plant (PI) and in the leaf positioned just below the point of insertion of the main ear (AFA). The trials followed a randomized block design with plots represented by a 5 m long rows. Differences among combining ability estimates for different environments and in both evaluation methods showed significant effects (P &lt; 0.01) for environment (E), GCA, and GCA × E. The SCA, and SCA × E effects were not significant for any of the disease severity variables. The GCA effects were more important than SCA for this set of inbred lines, suggesting that additive genetic effects are the most important sources of variation for this trait. Heterosis effects for resistance were estimated, and it was possible to identify specific hybrid combinations between lines which have high potential for genetic control of this pathogen. Results for both disease severity variables were practically identical, even though the PI method was more convenient to use.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000100007
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162004000100007
Formato: | text/html
Fonte: | Scientia Agricola  v.61 n.1 2004
Fonte: | info:eu-repo/semantics/openAccess