Data/hora: 09/06/2024 17:08:56

Provedor de dados: | 74
País: | Brazil
Título: | Reciprocal recurrent selection effects on the genetic structure of tropical maize populations assessed at microsatellite loci
Autores: | Pinto,Luciana Rossini; Vieira,Maria Lucia Carneiro; Souza Jr.,Claudio Lopes de; Souza,Anete Pereira de.
Data: | 2003-01-01
Ano: | 2003
Palavras-chave: | Population genetics; Plant breeding; Molecular markers.
Resumo: | A modified reciprocal recurrent selection (RRS) method, which employed one cycle of high-intensity selection, was applied to two tropical maize (Zea mays L.) populations, BR-105 and BR-106, originating the improved synthetics IG-3 and IG-4, respectively. In the present study the effects of this kind of selection on the genetic structure of these populations and their synthetics were investigated at 30 microsatellite (SSR) loci. A total of 125 alleles were revealed. A reduction in the number of alleles was observed after selection, as well as changes in allele frequencies. In nearly 13% (BR-105) and 7% (BR-106) of the loci evaluated, the changes in allele frequencies were not explained, exclusively due to the effects of genetic drift. The effective population sizes estimated for the synthetics using 30 SSR loci were similar to those theoretically expected after selection. The genetic differentiation (G ST) between the synthetics increased to 77% compared with the original populations. The estimated R ST values, a genetic differentiation measure proper for microsatellite data, were similar to those obtained for G ST. Despite the high level of selection applied, the total gene diversity found in the synthetics allows them to be used in a new RRS cycle.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300022
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572003000300022
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.26 n.3 2003
Fonte: | info:eu-repo/semantics/openAccess