Genetic diversity study ofBrassica campestris L. ssp.chinensisMakino based on ISSR markers

Twenty ISSR markers were used to amplify the genome of Brassica campestris L. ssp. chinensis Makino (Pak-choi). A total of 173 scorable alleles have been detected among 68 B. campestris genotypes, and the polymorphic alleles was 84.21%. Average diversity index (I) was 0.4284, and the mean number of the per locus of effective alleles was 1.4796. Moreover, the mean value of the Nei’s gene diversity (He) was 0.2883. The results revealed a higher genetic diversity in B. campestris from China than that from Japan and Thailand. The dendrogram divided the 68 B. campestris accessions into four groups. The dendrogram clustered the accessions of similar morphology together, and it indicated that the samples from the same geographical region were much closer than those from different regions. Meanwhile, the dendrogram also revealed that male sterile lines and their maintainer lines clustered together.