Abstract: ObjectiveThe objective of this research was to explore genetic diversity and genetic relationship of Picria felterrae Lour.breeding materials and to provide reference for breeding materials selection and genetic improvement.MethodUsing SSR molecular marker,gene diversity index (Nei),shannon diversity information index (I),percentage of polymorphic loci (P) and genetic distance of 12 breeding materials P.felterrae Lour.were analyzed.And cluster analysis was conducted based on genetic distance to study the genetic diversity and genetic relationship of the 12 breeding materials.ResultA total of 73 alleles were amplified from 17 pairs of SSR primers,4.3 alleles per primer.Among the primers,P varied between 8.33%-100.00%,with an average of 60.78%;polymorphic information content(PIC) varied between 0.0767-0.7598 which was 0.5184 on average.For the 12 germplasm samples tested,the average level of genetic diversity was Nei=0.3002,I=0.4162,and P=59.81%.Number xyj01,xyj06 and ytL09 had the highest Nei which was 0.3529,the highest I 0.4893 and the highest P 70.59%.Whereas Lxjl2 had the lowest level in Nei which was 0.2059,the lowest I 0.2854 and the lowest P 41.18%.Number ytl09 and zgb03 had the shortest genetic distance,which was 0.0929.The cluster analysis based on genetic distance revealed that the 12 germplasm samples could be divided into four groups at the location where genetic distance was 0.4084.Number wzhjx07,lxj09,and xyj01 made up three groups by themselves,and the rest was in the last group.There were close genetic relationships between Lxj12 and zgb04,between ytl11 and wzhjx09,between ytl09 and zgb03,between wzhjx12 and xyj06,wzhzp22.ConclusionCertain genetic difference exists in the 12 tested Picria felterrae Lour.breeding materials,which are valuable in terms of selection of parents in breeding.