Abstract:

To evaluate the genetic diversity and variation of common wild rice and Asian cultivated rice, 55 accessions of common wild rice (32 O. rufipogon and 23 O. nivara) and 25 cultivars of Asian cultivated rice (14 indica and 11 japonica) collected worldwide were analyzed by 56 SSR primer pairs. The polymorphic loci percentage was 98.68% and 298 polymorphic loci were detected. A comparison of the polymorphic loci percentage and Nei’s genetic diversity (h) indicated that the genetic diversity of common wild rice was obviously higher than that of Asian cultivated rice. The UPGMA cluster analysis revealed that there was a close relationship between O. rufipogon and O. nivara, but distinct genetic differentiation was detected between them, supporting the piont of view that they are two independent species. The results indicated that the indica-japonica differentiation was not very apparent in many wild rice whereas it was obvious in Asian cultivated rice. According to the cluster analysis, there was a closer consanguineous relationship between Asian cultivated rice and O. rufipogon, which supported the diphyletic origin hypotheses.

Key words: SSR, Cultivated rice, Common wild rice, Genetic diversity