利用ISSR标记对15份新麦草(Psathyrostachys juncea)种质资源进行遗传多样性检测。为获得稳定的新麦草ISSR反应体系，对反应条件中的dNTP、Taq酶浓度、引物浓度、Mg2+浓度等因子进行了优化，建立起的最佳反应体系为:25μL的反应体系中含有dNTP 2．5μL、Taq酶0．2μL、Primers 1μL、Mg2+1．5μL、2．5μL 10×Buffer、2μL模板DNA和ddH2O 15．3μL。ISSR标记结果显示，筛选出的重复性好、谱带清晰的ISSR引物8条，共获得84个扩增位点，其中多态性位点72个，多态性比率(PPB)为85．7%。通过遗传相似系数(GS)的计算，供试种质材料间的GS值在0．4405～0．9048之间，表现出丰富的遗传多样性。通过聚类分析，将15份新麦草种质材料划分为四大类，且呈现出一定的地域性分布规律。
The genetic diversities of 15 Psathyrostachys juncea germplasm resources were analyzed by ISSR molecular marker.Based on the basic system,four factors of Taq DNA polymerase,random primers,Mg2+,and dNTPs which affect ISSR-PCR amplifying results of P.juncea were optimized.An optimal ISSR-PCR system including 2.5μL dNTPs,2μL template DNA,0.2μL Taq DNA polymerase,1μL random primers,1.5μL Mg2+,2.5μL 10×PCR Buffer,15.3μL ddH2O,and the total volume was 25μL,was established.The results of ISSR marker showed that 8 primers,which could show clearer bands and had good repetition,were selected from 25 primers and detected a total of 84 bands,among which 72 bands were polymorphic.The average percentage of polymorphic bands (PPB) was 85.7%.According to 0.4405-0.9048 of the GS values,the germplasm and materials of P.juncea showed rich genetic diversity.Based on cluster analysis of the genetic characteristics,15 P.juncea germplasm could be divided into 4 groups according to the nearest phylogenetic relationship.In most cases,the germplasm and materials from the same country were in the same group and showed the definite rules of geographical distribution.
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