云南栽培稻种SSR遗传多样性比较

Comparative Assessment of Simple Sequence Repeat Genetic Diversity in Cultivated Rice from Yunnan

采用64个SSR标记对96份云南水稻(Oryza sativa)地方品种和选育品种的遗传多样性进行比较分析。结果发现64个标记都具有多态性,共检测到741个等位基因,每个多态性位点检测到的等位基因数为2-29个,平均11.57个;Nei基因多样性指数(He)范围在0.345(RM321)-0.932(RM1)之间,平均为0.56。水稻品种的遗传多样性并非按地理位置均匀分布,而是在相似系数为0.17的水平上明显分为2个不同类群,即籼稻类群和粳稻类群,且籼粳亚种间的SSR多样性差异不明显,籼稻平均等位基因数(Ap)和Nei基因多样性指数(Ap=10.6,He=0.46)与粳稻品种(Ap=10.7,He=0.48)十分接近,可能与这些品种间存在一定频率的基因交流有关。糯稻和非糯稻在籼稻群和粳稻群中都有表现,没有特别的分布规律。云南栽培稻选育品种与地方稻亲缘关系较近,其遗传基础可能来源于云南水稻地方品种。本研究结果表明,SSR标记能较好地区分云南栽培稻品种,且云南水稻地方品种遗传多样性丰富,存在大量的优质性状可供育种实践选择。

A total of 64 simple sequence repeat （SSR） markers were used to investigate the genetic diversity of 96 rice landraces and improved varieties from Yunnan; all of the 64 SSR loci were polymorphic. A total of 741 alleles were detected. Each locus contained 2-29 alleles, for a mean of 11.57 alleles; the mean genetic diversity index （He） of Nei was 0.56, with scope from 0.345 （RM321） to 0.932 （RM 1）. The genetic diversity of the rice varieties from Yunnan was not evenly distributed according to geographical locations. Two distinct groups （indica and japonica rice） were identified for the 96 rice varieties, with a similarity coefficient of 0.17. There was no significant difference in SSR diversity between indica and japonica subspecies. The mean number of alleles （Ap） and mean Nei genetic diversity index for indica rice （Ap=10.6, He=0.46） were close to those of japonica rice （Ap=10.7, He= 0.48）. The similarity of these indices may be related to a certain frequency of the gene exchange. Non-glutinous rice and glutinous rice were scattered in the rice group, and the genetic basis of cultivated rice may be from these local varieties. Yunnan cultivated rice can be distinguished by SSR markers, and the genetic diversity of rice landraces from Yunnan is rich. A large number of highquality characters are available for selection in rice breeding.