Analysis Of Genetic Diversity In Vegetable Crops Of Brassica Campestris By AFLP Molecular Markers

Several techniques of DNA molecular markers have rapidly been used in Brassica plants,however,there is so far no report on the use of AFLP(Amplif led Fragment Length Polymorphism) for analyzing their phylogenetic relationship. In this work, AFLP was used in the study of the genetic polymorphism among different crops of Brassica campestrzs L., including 139 cultivars of the 3 subspecies B. campestris ssp pekinensis O]sson, ssp chinenesis Makino, and ssp rapifera Ala tzg. After being tested over these cultivars, four (E7Ml.~ E6Ml~ E4MI and E4M3)of the 62 pairs of AFLP primers were screened. B. campestris ssp pekinensis and ssp chinenesis show high level (75%) of polymorphism and the cultivars of B. campestris ssp rapifera relatively lower(53%). The phylogenetic tree was constructed using UPGAM(Unweighted Pair梘roup Average Method).Turnip ( B. cainpestris ssp rapifera ) and Chinese cabbage (B. cawpestris ssp pekinensis and ssp chinenesis) were clustered into two distinct groups, stggesting that they be the two subspecies of B.rapa. Our results ferther support the hypotheses that turnip and Chinese cabbage were of different origins and the vegetable crops, such as wuta梒ai and tsai梩ai were only different varieties of B. ca,npestris ssp chinenesis. This work demonstrated that AFLP is a highly efficient and reliable method for the identifecation of different cultivars of Brassica crops.