Identification of molecular markers associated with sex in kartoli (Momordica dioica Roxb.)

Sexual dimorphism is the rule in most animals. In the plant kingdom however, dioecy is found only in 4% of the angiosperms. Dioecism has originated independently in different families and genera and several distinct genetic mechanisms regulating dioecy have been found in different plant species. Sex determination mechanism in plants is not well-understood. Neither the genetic nor the physiological basis of gender has been completely resolved in any plant species, in spite of the striking progress made over the floral development. More often, the sex ratio in dioceous plant species is controlled by the expression of alleles' at one to several loci. Genetic marker system based on direct analysis of the genomic DNA has been used widely for genetic mapping, disease diagnostics and evolutionary studies and they could prove very useful in the study of sexual determination in dioecious plants. In the present study, Momordica dioica Roxb. plant was investigated for the molecular basis of genotypic differentiation between male and female plants using randomly amplified polymorphic DNA technique. In the present investigation, out of the 47 primers used, 30 primers amplified and showed polymorphism in this crop. These primers produced 12 sex specific bands present only in one sex of kartoli. Therefore individual analysis was carried out using 10 RAPD primers. But these bands are not reproducible during individual analysis. Only one primer OPA-15 produced a female specific band having size 835 bp during bulk analysis. It was confirmed by taking bulk analysis in replications and it is reproduced in bulk analysis, which indicates that the genome of kartoli is more conserved and more primers need to be screened to identify sex specific bands.