利用微卫星标记比较云南元阳哈尼梯田两个不同时期种植的水稻地方品种的遗传多样性

Comparison of Genetic Diversity of Rice Landraces Planted in Two Periods in Hani′s Terraced Fields in Yuanyang County,Yunnan Province,China Using Microsatellite Markers

为了揭示云南元阳哈尼梯田两个不同时期种植的水稻地方品种的遗传多样性,以元阳哈尼梯田过去种植(20世纪70年代收集于元阳县,现保存于种质库)的72个和当前种植的76个品种为材料,采用48个SSR分子标记进行多态性、遗传相似性和聚类分析。平均每个标记检测到的等位基因数、有效等位基因数、位点多态信息含量和基因型多样性指标在过去与当前的品种间,差异均未达显著水平。共有24个SSR标记的52个等位基因位点在过去与当前种植的品种中存在差异,其中,有18个SSR标记的32个等位基因位点在当前的品种中未检测到,同样,有16个SSR标记的20个等位基因位点在过去的品种中未检测到。基于48个SSR分子标记的平均遗传相似性系数,当前种植的品种为0.3340,过去为0.3313,过去与当前的品种分别在遗传相似性系数0.203和0.174处分为籼、粳两个亚种群。表明元阳哈尼梯田水稻地方品种经过30多年的自然与人工选择,虽有部分等位基因位点发生了变异,但仍保留了原有的遗传多样性;元阳哈尼梯田水稻地方品种存在明显的籼、粳分化。元阳哈尼梯田及其水稻地方品种是研究稻作籼粳演化的理想基地和材料。

To compare the genetic diversity of rice landraces in different periods polymorphism,genetic similarity and cluster analyses were conducted with 148 rice landraces by using 48 SSR markers.The materials included 72 landraces collected during the 1970s（past-grown landraces） and 76 grown during the past decade（current-grown landraces） in Hani′s terraced fields in Yuanyang County,Yunnan Province.The results showed that the differences between the two periods in all indices,including average number of alleles,effective number of alleles,locus polymorphism information content and genotype diversity were not significant.Furthermore,52 alleles of 24 SSR markers differed between the past-grown and the current-grown landraces,among which 32 alleles of 18 SSR markers were not detected in the current-grown landraces and 20 alleles of 16 SSR markers were not detected in the past-grown landraces.The average genetic similarity coefficient of the current-grown landraces was 0.3340,and that of the past-grown landraces was 0.3313.The current-grown and past-grown landraces were divided into japonica and indica subspecies at the genetic similarity coefficient of 0.174 and 0.203,respectively.These results indicated that for more than 30 years′ natural and artificial selection,there were variations in some of the allele locus of the rice landraces from Hani′s terraced fields with high genetic diversity.In addition,the indica-japonica subspecies differentiation was obvious in the landraces from Hani′s terraced fields in Yuanyang,and the differentiation seemed to be ongoing,indicating that Hani′s terraced fields and the rice landraces might be ideal tested field and materials for the study of indica-japonica subspecies evolution.