IDENTITIES AND RELATIONSHIPS AMONG CHINESE VEGETABLE BRASSICAS AS DETERMINED BY RANDOM AMPLIFIED POLYMORPHIC DNA MARKERS

Fifty-two germplasm accessions of Chinese vegetable brassicas were ana lyzed using 112 random amplified polymorphic DNA (RAPD) markers. The a rray of material examined spanned a wide range of morphological, geogr aphic, and genetic diversity, and included 30 accessions of Brassica r apa L. (Chinese cabbage, pakchoi, turnip, and broccoletto), 18 accessi ons of B. juncea (L.) Czern. (leaf, stem, and root mustards), and four accessions of B. oleracea L. ssp, alboglabra (Chinese kale). The RAPD markers unambiguously identified ah 52 accessions. Nei-Li similaritie s were computed and used in unweighted pair group method using arithme tic means (UPGMA) cluster analyses. Accessions and subspecies were clu stered into groups corresponding to the three species, but some access ions of some subspecies were most closely related to accessions belong ing to other subspecies. Values for Nei-Li similarities suggest that C hinese cabbage is more likely to have been produced bg hybridization o f turnip and pakchoi than as a selection from either turnip or pakchoi alone. RAPD markers are a fast, efficient method for diversity assess ment in Chinese vegetable brassicas that complements techniques curren tly in use in genetic resources collections.