Inbreeding depression of 28 maize elite open pollinated varieties.

The study of inbreeding depression is important for breeding strategies such as use of inbred progenies or extraction of inbreed lines. A diallel of 28 maize open-pollinated varieties was evaluated in 10 environments in the early 1990s. At the same time, S1 populations for each of the 28 varieties w...

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Detalhes bibliográficos
Autores: PACHECO, C. A. P., SANTOS, M. X. dos, CRUZ, C. D., PARENTONI, S. N., GUIMARAES, P. E. de O., GAMA, E. E. G. e, SILVA, A. E. de, CARVALHO, H. W. L.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2002
País:Brasil
Recursos:Empresa Brasileira de Pesquisa Agropecuária (Embrapa)
Repositório:Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
Idioma:inglês
OAI Identifier:oai:www.alice.cnptia.embrapa.br:doc/488462
Acesso em linha:http://www.alice.cnptia.embrapa.br/alice/handle/doc/488462
Access Level:Acceso aberto
Palavra-chave:Endogamy
Maize
Diallel
breeding
inbreeding depression
Descrição
Resumo:The study of inbreeding depression is important for breeding strategies such as use of inbred progenies or extraction of inbreed lines. A diallel of 28 maize open-pollinated varieties was evaluated in 10 environments in the early 1990s. At the same time, S1 populations for each of the 28 varieties were evaluated in the same 10 experiments (environments). Yield reductions of the populations from S0 to S1 (mean of the 10 environments), varied from 34.6% (CMS-01) to 59.2% (CMS-30), with an average of 49.1%. Inbreeding depression was greater in populations with a wider genetic base, which had never been exposed to inbreeding (CMS-30, BR-107, PH4, Cunha, Saracura, Nitrodent, and Nitroflint). Inbred lines with greater yield means should be obtained from the BR-105, BR-111, CMS-01, CMS-03, BR-106, CMS-14c, and CMS-28 populations. The use of parameter estimates generated by analysis of inbreeding depression, allow to make inferences about frequencies of deleterious alleles in the population. The frequencies of favorable alleles in the parents can be obtained by diallel analysis. The association of these two types of information, can provide a better interpretation of the genetic parameters and also can improve the process of selection of parents for either an intra- or an inter-populational breeding program.