Relative fitness of females and hermaphrodites in a natural gynodioecious population of wild radish, Raphanus sativus L. (Brassicaceae): comparison based on molecular genotyping.
J Evol Biol
; 22(10): 2012-9, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19678867
ABSTRACT
In many gynodioecious species, sex determination involves both cytoplasmic male-sterility (CMS) genes and nuclear genes that restore male function. Differences in fitness among genotypes affect the dynamics of those genes, and thus that of gynodioecy. We used a molecular marker to discriminate between hermaphrodites with and without a CMS gene in gynodioecious Raphanus sativus. We compared fitness through female function among the three genotypes females, hermaphrodites with the CMS gene and those without it. Although there was no significant difference among the genotypes in seed size, hermaphrodites without the CMS gene produced significantly more seeds, and seeds with a higher germination rate than the other genotypes, suggesting no fitness advantage for females and no benefit to bearing the CMS gene. Despite the lack of fitness advantage for females in the parameter values we estimated, a theoretical model of gynodioecy shows it can be maintained if restorer genes impose a cost paid in pollen production. In addition, we found that females invest more resources into female reproduction than hermaphrodites when they become larger. If environmental conditions enable females to grow larger this would facilitate the dynamics of CMS genes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transtornos do Desenvolvimento Sexual
/
Raphanus
/
Óvulo Vegetal
Idioma:
En
Revista:
J Evol Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Japão