Abstract: ISSR markers were used to analyze the genetic diversity and genetic relationship of germplasm of Compositae,to preserve and identify Germplasm resources.ISSR-PCR was used to amplify 40 medicinal plants from 40 representative genera of Asteraceae,which were conserved in The State Bank of Chinese Drug Germplam Resources.PCR products were detected by agarose gel electrophoresis,and the polymorphisms were analyzed by NTSYS-pc2.1.The genetic tree was constructed by UPGMA.In this experiment,8 primers were screened,68 loci were amplified from 40 species of Compositae medicinal plants.And the percentage of polymorphic loci was 100%.The genetic similarity coefficient ranged from 0.71 to 0.91.The results of UPGMA cluster analysis showed that the 40 species of compositae medicinal plants could be divided into seven categories at 0.75 similarity coefficient.The 40 genera collected have rich genetic diversity and the 8 ISSR primers can be used for molecular identification of germplasm resources.

Key words: compositae, ISSR, UPGMA, genetic diversity, molecular identification