Low levels of genetic diversity within populations and high differentiation among populations of a wild rice, Oryza granulata Nees et Arn. ex Watt., from China

To characterize genetic diversity within and among populations of Oryza gra nulata Nees et Am. ex Watt., allozyme variation was assayed for 17 loci in 15 natural populations from Hainan and Yunnan provinces, China, using starc h gel electrophoresis. A low level of genetic variability within population s (the mean A 1.09, p = 6.33%, H-e = 0.016, and H-o = 0.009), but high gene tic differentiation (F-ST) among populations was observed. The low amount o f genetic variability of the species may be strongly affected by founder ef fect because of the marginal nature of the populations in China. The result s also indicate that the restricted gene flow occuring between the two regi ons as well as the characteristics of O. granulata as a colonizing plant sp ecies are probably of significance in shaping the observed population genet ic structure. Finally, an appropriate strategy for sampling more population s, but fewer individuals within populations, was proposed for the conservat ion of O. granulata in China.