A study of the genetic diversity of common wild rice (O. rufipogon Griff.) and cultivated rice (O. sativa L.) by RFLP analysis

The genetic diversity of cultivated rice and common wild rice from 10 countries in Asia were evaluated by RFLP analysis using 44 probes of single copy. We used the parameters such as proportion of polymorphic loci (P), average number of alleles per locus (A), average number genotype per locus (Ng), degree of heterozygate per locus (Ho) and average gene diversity (Hs) showing genetic diversity. It is indicated that the common wild rice from China has the largest genetic diversity in the 10 countries, and the secondary is the common wild rice from India. The results also showed that the genetic diversity in Chinese common wild rice is larger than the genetic diversity in common wild rice of South and Southeast Asia. The average gene diversity (Hs) of South Asian wild rice is higher than Southeast Asian wild rice, while the parameters value of proportion of polymorphic loci (P), average number of alleles per locus (A) and average number genotype per locus (Ng), Southeast Asian wild rice is higher than South Asian wild rice. It is found that the genetic diversity in cultivated rice is obviously lower than in common wild rice. In the detected 44 loci, the number of polymorphic loci on O. sativa is as the same as 3 / 4 in O. rufipogon, the number of alleles in O. sativa is as the same as 60% in O. rufipogon, the number of genotype in O. sativa is as same as 1/2 in O. rufipogon. In O. sativa, the genetic diversity of indica is larger than that of japonica. O. rufipogon from China have highest value in degree of hetrozygate per locus (Ho), and Ho of wild rice is as two times as cultivated rice. It is showed that in the proceeding of wild rice evolved into cultivated rice, Ho and number of alleles was reduced, and the genetic diversity was decreased.