Abstract: 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.

Key words: Psathyrostachys juncea, ISSR molecular marker, Genetic diversity, Cluster analysis

CLC Number: 

• S543.03