Infra-Specific Genetic Diversity of Ochradenus Baccatus Delile, a Gynodioecious Species in Egyptian Flora

Ochradenus Delile is a small genus of 6-9 species within family Resedaceae. In Egypt, it is only represented by the gynodioecious Ochradenus baccatus Delile, the most widespread species across the entire range of the genus. Within Egypt, field populations and herbarium specimens of O.baccatus showed vast morphological and gender diversity within and between different populations even in the same habitat. This enhanced authors to apply additional genotypic information using RAPD technique to differentiate between the studied O.baccatus forms and populations to support the taxonomic identification of this species. The morphological examination revealed the presence of four transitional inconstant male forms (MF1-MF4) and three female forms (FF1-FF3) on the basis of their floral and fruit traits.The prescreening of the studied forms using twenty primers resulted in 109 scorable bands of which 50 (45.9 %) were polymorphic. All the primers used developed monomorphic bands with the studied O.baccatus forms ranged from 3 in OPZ-13 primer to 6 in OPD-05 primer. This study revealed the detection of certain RAPD bands characterized and linked to different sex forms. The range of Nei’s genetic diversity among the studied forms appeared to be relatively limited (0.050.25). The UPGMA dendrogram obtained from RAPD results fit the calculated genetic distance and allowed two main groups to be distiguished. Group 1 included male forms and Group 2 included female forms. The results of this study suggested that the evolution of dioecy is associated with a significant decline in the amount of genetic diversity, and confirmed the presence of internal (genetic) factors controlling formation of the sex forms in the gynodioecious Ochradenus baccatus in Egypt not environmental factors.