沙生冰草遗传多样性的SSR分析

Genetic Diversity of Agropyron Deserotum Schult Originating from China Based on SSR

为给进一步保护、收集和利用沙生冰草种质资源提供依据，采用26个多态性小麦SSR引物对采集自中国不同生态环境的18个沙生冰草居群进行遗传多样性的SSR分析。结果表明，26个SSR引物多态性带纹数目变化为2～27条，平均每个引物在沙生冰草居群中扩增出了9．384条多态性带纹；不同引物间总遗传多样性指数最高为0．944（引物Xgwm544），最低为0．375（引物Xgwm257），平均遗传多样性指数为0．745；SSR检测到地区内遗传多样性占总体的82．2％，地区间为17.8％；在Nei遗传距离0．67处，18个沙生冰草居群被分为3个类群；UPGMA聚类和PCA分析表明，采集地生态环境相似的沙生冰草居群遗传距离较近。沙生冰草遗传多样性与居群的遗传和生态环境相关，在沙生冰草的有效保护和持续利用中，对其主要生态环境居群保护和利用基础上还需进一步加强不同生态环境中特异类型居群的保护和研究。

The objective of the present study was to investigate the genetic variation and structure of A. deserotum（Fisch, ex Link） Schult. populations collected from various geographic areas in Northern China. Eighteen populations ot Agropyron desertorurn originated from various regions of Northern China were used for SSR analysis with 26 pairs of polymorphic primers previously mapped on wheat genome. The result showed the polymorphic band number changed from 2 （Xgwm285） to 27 （Xgwm544） with the mean value of 9. 384. The genetic diversity values ranged from 0. 944 in Xgwm544 to 0. 375 in Xgwm257 with the mean value of 0. 745 over all populations. The proportion of diversity among and within regions indicated that 82.2% of the total variation occurred within a region,and 17.8% among regions by SSR analysis. In Nei＇s distance of 0.67, the populations of A. desertorum were divided into 3 groups. The phenogram and the principal coordinate analysis of SSR data indicated that populations from the similar ecogeographical areas clustered together and suggested that more attention should be paid to special populations of different regions in regard to collection and preservation of A. desertorum gerrnplasm.