Data/hora: 13/06/2024 04:34:10

Provedor de dados: | 74
País: | Brazil
Título: | Mating system in a natural population of Theobroma grandiflorum (Willd. ex Spreng.) Schum., by microsatellite markers
Autores: | Alves,Rafael M.; Artero,Angela S.; Sebbenn,Alexandre M.; Figueira,Antonio.
Data: | 2003-01-01
Ano: | 2003
Palavras-chave: | Amazonia; Germplasm; Cupuassu; Genetic conservation; Simple sequence repeat.
Resumo: | The aim of this research was to study the mating system of a natural population of Theobroma grandiflorum (cupuassu) from Nova Ipixuna, Pará state, using microsatellite markers. Eight polymorphic microsatellite loci were analyzed in eight families, each represented by 10 six-month old seedlings derived from open-pollinated pods. The estimation for the multilocus outcrossing rate (&lt;img border=0 id="_x0000_i1026" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt;m = 1.0) and individual outcrossing rate (&lt;img border=0 id="_x0000_i1027" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt; = 1.0) for this population suggests that T. grandiflorum may be a perfect outbreeding (allogamous) species. Likewise, for the studied population the estimate for single locus outcrossing rate (&lt;img border=0 id="_x0000_i1028" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt;S) was elevated (0.946), but lower than &lt;img border=0 id="_x0000_i1029" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt;m, confirming the likely outcrossing character of the species and suggesting the occurrence of 5.4% biparental inbreeding rate (&lt;img border=0 id="_x0000_i1030" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt;m - &lt;img border=0 id="_x0000_i1031" src="../../img/revistas/gmb/v26n3/a25img01.gif" align=absmiddle&gt;S). The estimation of genetic divergence (&lt;img border=0 id="_x0000_i1032" src="../../img/revistas/gmb/v26n3/a25img02.gif" align=absmiddle&gt;st) between allelic frequencies in ovules and pollen revealed a deviation from random mating in 75% of the evaluated loci. Likewise, the estimate of correlation of paternity (&lt;img border=0 id="_x0000_i1033" src="../../img/revistas/gmb/v26n3/a25img03.gif" align=absmiddle&gt;P = 0.930) and the mean coefficient of co-ancestrality within families (&lt;img border=0 id="_x0000_i1034" src="../../img/revistas/gmb/v26n3/a25img04.gif" align=absmiddle&gt;XY = 0.501) indicated that the outcrossings were predominantly correlated, and the offspring were full-sibs. These results suggested that for this particular population of T. grandiflorum, the sampling strategy for genetic conservation and breeding should adopt specific models for families derived from correlated outcrossing (full-sibs) and not the ones usually adopted in classic outcrossing species breeding programs (half-sibs).
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572003000300025
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572003000300025
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.26 n.3 2003
Fonte: | info:eu-repo/semantics/openAccess