The genetic basis of gender in Silene vulgaris

Abstract

Inheritance of gender was studied in tetraploid Silene vulgaris in Israel. Three main phenotypes, hermaphrodite, H, female, F, and intermediate HF, were recognized. With the support of data from crosses within and between the phenotypes it is postulated that basic gender is controlled at a single tetrasomic locus AA/aa. Quadruplex and triplex AAAA and AAAa individuals exhibit phenotype H, simplex and nulliplex aaaa and Aaaa individuals phenotype F, and AaAa individuals phenotype HF. Predominantly hermaphrodite or predominantly female subgroups of the HF phenotype are liable to be confused with true H or F types, so that misclassifications may blurr the underlying genetic pattern. In the HF phenotype, in which A is assumed to be incompletely dominant over a, expression of male sterility is confined to single flowers or single anthers in a pattern with the appearance of randomness. The question is asked whether the mosaic pattern of sex expression in heterozygotes may reflect vegetative segregation of dissimilar cytoplasmic male sterility factors which are controlled by nuclear restorer genes.