| Heading Chinese cabbage is one of the most important vegetable in Asia, especially in China, Japan and Korea. Turnip mosaic virus (TuMV) is the most important virus disease in Chinese cabbage, and reduces not only crop yield but also quality of the produces. TuMV is transmitted in a non-persistent manner by over 40 aphid species. Attempts to control vector with insecticides have been unsuccessful. Among the strains, TuM V-C4 is the most predominant. The development of virusresistant varieties is likely to be the most effective, environmentally friendly and sustainable approach to control viral disease. It is important to identify resistance genes effective against the virus, to obtain information on their mode of inheritance and to incorporate these into improved cultivars. Molecular markers are considered to be one of the most useful tools to assist in the selection of strainpecific resistance genes. The study was carried out using a F2 population from a cross between resistant inbred line and susceptible inbred line. Bulked segregant analysis (BSA) was applied to identify RAPD markers linked to the resistance to TuMV. The main results are as follows:1.At the five-leaf stage, the plants were inoculated with TuMC-C4 strain. Segregation ratio obtained by visual observation and enzyme-linked immunosorbent assy (ELISA) was 3:1. x 2 = 0.068 and less than x 2 O.05(df=I) = 3.84. This indicates that the resistance to TuM V-C4 is controlled by a dominant gene.2.Total 1021 fragments were analyzed using 242 primers. Two RAPD markers were identified to be linked with the resistant gene. The genetic distances between the resistant gene and two RAPD markers was 9.51 and 15.36 cM respectively.3.The possible application of molecular markers to current breeding programs and future cloning of the resistant gene were discussed.
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