Data/hora: 10/06/2024 02:34:05

Provedor de dados: | 63
País: | Brazil
Título: | Isoenzymatic variability in tropical maize populations under reciprocal recurrent selection
Autores: | Pinto,Luciana Rossini; Vieira,Maria Lúcia Carneiro; Souza Jr.,Cláudio Lopes de; Silva,Rainério Meireles da.
Data: | 2003-01-01
Ano: | 2003
Palavras-chave: | Zea mays; Genetic markers; Genetic variability; Isozymes; Population improvement.
Resumo: | Maize (Zea mays L.) is one of the crops in which the genetic variability has been extensively studied at isoenzymatic loci. The genetic variability of the maize populations BR-105 and BR-106, and the synthetics IG-3 and IG-4, obtained after one cycle of a high-intensity reciprocal recurrent selection (RRS), was investigated at seven isoenzymatic loci. A total of twenty alleles were identified, and most of the private alleles were found in the BR-106 population. One cycle of reciprocal recurrent selection (RRS) caused reductions of 12% in the number of alleles in both populations. Changes in allele frequencies were also observed between populations and synthetics, mainly for the Est 2 locus. Populations presented similar values for the number of alleles per locus, percentage of polymorphic loci, and observed and expected heterozygosities. A decrease of the genetic variation values was observed for the synthetics as a consequence of genetic drift effects and reduction of the effective population sizes. The distribution of the genetic diversity within and between populations revealed that most of the diversity was maintained within them, i.e. BR-105 x BR-106 (G ST = 3.5%) and IG-3 x IG-4 (G ST = 4.0%). The genetic distances between populations and synthetics increased approximately 21%. An increase in the genetic divergence between the populations occurred without limiting new selection procedures.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000200013
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162003000200013
Formato: | text/html
Fonte: | Scientia Agricola  v.60 n.2 2003
Fonte: | info:eu-repo/semantics/openAccess