Abstract: Forty-eight SSR markers were used to compare genetic diversity in 288 accessions of common wild rice (O. rufipogon Griff.) and cultivated rice (O. sativa L.) in China. There were 505 alleles at the 48 loci investigated. The average number of alleles per locus (Na) was 10.5 with a range from 5 to 20. Total Nei’s genetic diversity index of Nei per locus (He) varied widely from 0.384 (RM409) to 0.905 (RM206) with an average value of 0.731. By comparison of the genetic changes in Na and He, the genetic di-versity of common wild rice was obviously higher than that of cultivated rice. Na and He of cultivated rice was only about 70.2% and 88.2% of common wide rice, respectively. In cultivated rice, Na of landraces and improved varieties were 65.4% and 53.0% of common wild rice respectively, and Na of improved varieties was 81.1% of landraces. Analysis of molecular variance (AMOVA) indicated that 10.3% of the variation was from differences between species. Using locus-by-locus AMOVA procedure, there were 43 loci with significant differentiation. The highest genetic differentiation was 46.3% (RM427) with a range from 0.7% to 46.3%. A cluster analysis showed japonica was the main trend for most of common wild rice in China. In addition, only a few of accessions from Guangdong and Hainan showed tendency towards indica type.

Key words: Common wild rice (O. rufipogon), Cultivated rice (O. sativa), Landrace, Improved variety, Genetic diversity, Analysis of molecular variance