桂东南地区普通野生稻遗传多样性研究

利用25个微卫星位点对广西壮族自治区贺州、崇左、防城港3市8个居群301份普通野生稻材料的遗传多样性和遗传结构进行研究,结果表明桂东南地区普通野生稻遗传多样性丰富,平均等位基因数A=10.2400,有效等位基因数Ae=5.0221,平均期望杂合度He=0.7641,实际观察杂合度Ho=0.4840.根据固定指数(F=0.5653)计算出的异交率(t=0.2777)表明,普通野生稻的繁育系统是典型的混合繁育系统.对其遗传结构分析表明,总的遗传变异中有34.59%存在于居群间(Fst=0.3459).进一步研究发现大多数居群偏离了Hardy-Weinberg平衡且杂合体不足(Fis=0.2680,Fit=0.4817).最后根据各居群的遗传变异特点和遗传多样性比较,建议居群QT、YJ和TJ需要优先保护.

Genetic Diversity of Oryza rufipogon Griff. in Southeast Region of Guangxi in China

To estimate genetic diversity of Oryza rufipogon Griff. in Southeast region of Guangxi in China, a total of 301 individuals form 8 natural populations in Hezhou City, Fangchenggang City and Chongzuo City were analyzed using 25 microsatellites loci. A moderate to high level of genetic diversity was observed at population levels with the mean number of alleles (A) ranged from 2.0400 to 5.2000 (overall 10.2400). The effective number of alleles (Ae) ranged from 1.5337 to 2 .9921 (overall 5 .0221) . The mean expected heterozy-gosity (He) ranged from 0.2838 to 0.5840 (overall 0.7641). The observed heterozygosity (Ho) ranged from 0.2150 to 0.5753 (overall 0.4840). An estimate of the outcrossing rate (t = 0.4570) suggests that the species has a typical mixed-mating system. Furthermore, a moderate genetic differentiation ( Fst = 0.3459) was found among the populations studied, suggesting that 35.49% genetic variation existed among the populations. Moreover, microsatellite showed less deviation from Hardy-Weinberg expectation within and among populations (Fis = 0.2680, Fit = 0.4817) and a slight deficiency of heterozygotes. Eventually together with the pattern of genetic differentiation of natural populations of Oryza rufipogon in Southeast region of Guangxi, it could be suggested that the population QT, YJ, TJ be given priority for in-situ conservation.