中文摘要：

蒙古冰草因其抗寒、抗旱特性,是欧亚大陆荒漠草原优势植物之一.本文从染色体倍性及SSR 序列长度多态性两个方面对采自中国北方境内的9个蒙古冰草居群进行遗传多样性分析,发现9个蒙古冰草居群染色体基数为7,均为二倍体,在染色体倍性方面不具有多态性;共采用138对小麦SSR 引物进行扩增分析,共有21对引物扩增出特异性条带,SSR 引物筛选率15.2%.共扩增出特异性条带119 条,平均每对引物扩增出特异性条带5.6 条,SSR 序列长度多态性丰富.利用POPGEN32软件计算9个蒙古冰草居群遗传多样性指标,居群P8 遗传多样性程度最低,居群P3 最高.AMOVA 分析显示,蒙古冰草的遗传差异主要是来自居群内个体之间.UPGMA 方法聚类分析,在遗传相似系数为0.80时,9个居群被分为三大类,居群P1～P6 一类,居群P7、P8 为第二类,P9 被单独分为一类.本研究为了解蒙古冰草遗传背景及加速其资源的合理开发利用奠定了理论基础.

英文摘要：

Agropyron mongolicum is one of the dominant species in desert steppe across Eurasia,due primarily to its cold and drought resistance.In this study,we analyzed chromosome polymorphism and DNA polymor-phism in 9 populations of A.mongolicum in northern China.The chromosome number of the 9 populations was 7.Cells were diploid and showed no polymorphism in chromosome ploidy.A total of 138 pairs of wheat SSR primers were amplified and analyzed.A total of 21 primer pairs were amplified with specific fragments. The screening rate of SSR primers was 15.2%.A total of 119 specific bands were amplified:specificity was 5.6 and the polymorphism of DNA was rich.POPGEN 32 software was used to calculate the genetic diversity of the 9 populations of A.mongolicum.Population P8 was found to have the least level of diversity,while P3 had the highest.AMOVA software was used to analyze genetic differentiation,indicating that genetic differ-ences come mainly from individuals in the populations.The UPGMA method was used for a cluster analysis of the 9 populations.When the genetic similarity coefficient is 0.80,the materials tested divided into three groups:P1 -P6 ,P7 -P8 and P9 .This paper lays the foundation for the development and utilization of new vari-eties of A.mongolicum.