云南地方水稻品种遗传多样性分析及其保护意义

为了研究云南地方水稻品种遗传多样性水平。对采自云南17个村落的82份品种以及代表籼粳不同类型的3份标准样的遗传背景进行SSR分析。19对引物共检测出83条多态带(分子量变异范围是100～500bp)。根据L71K；MA法用遗传相似系数进行聚类分析。结果表明，这85份水稻品种遗传相似系数在0．152～0．900之间存在显著的遗传变异。这些品种的遗传多样性并非均匀的按地理位置分布，而是在相似系数为0．152的水平上明显分为2个不同类群：籼稻类群和粳稻类群。从不同村落采集的叫同一名称的品种的遗传背景并不相近。研究表明，保护云南地方水稻品种十分必要，但是需要制定合适的策略，确保有效保护活动。另外选择合适的SSR引物是区分籼粳类型的理想手段。

Genetic Diversity of Rice Landraces from Yunnan Revealedby SSR Analysis and Its Significance for Conservation

Eighty-two rice varieties, including rice landraces collected from 17 villages in Yunnan Province of China and three standard varieties representing typical Indica and Japonica ecotypes, were studied by using simple sequence repeat (SSR) markers to estimate their genetic diversity for the purpose of conservation. Nineteen selected SSR primer pairs amplified a total of 83 SSR alleles, with molecular weight SEK1] ranging from 100 to 500 bp, from the 85 rice varieties. An UPGMA dendrogram based on the cluster analysis of genetic similarity of the SSR alleles showed a significant genetic variation among the included rice varieties, with the similarity coefficients varying between 0.152 and 0. 900. However, genetic diversity of the rice varieties collected from Yunnan was not evenly distributed over their geographical locations. Two distinct groups were identified for the 85 rice varieties at the similarity coefficient level of 0. 152, with one group that included almost all accessions of Indica ecotype and another group that contained all accessions of Japonica ecotype. Varieties that shared the same names and collected from different villages did not always show a close genetic relationship, indicating misidentifica-tion of some varieties by local farmers. It is concluded from the study that conservation of genetic diversity in rice landraces is necessary, but an appropriate strategy needs to be followed to guarantee the effectiveness of conservation activities. Analysis with appropriately selected SSR primer pairs might provide an ideal method for identifying Indica and Japonica eco-types for rice conservation and breeding.