The dominant genic male sterility (DGMS) gene CDMs399-3 derived from a spontaneous mutation in the line 79-399-3 of spring cabbage (Brassica oleracea var. capitata L.), has been successfully applied in hybrid seed production of several cabbage cultivars in China. During the development of dominant male sterility lines in cabbage, the conventional identification of homozygous male-sterile plants (CDMs399-3/CDMs399-3) is a laborious and time-consuming process. For marker-assisted selection (MAS) of the gene CDMs399-3 transferred into key spring cabbage line 397, expressed sequence tag-simple sequence repeats (EST-SSR) and SSR technology were used to identify markers that were linked to CDMs399-3 based on method of bulked segregant analysis (BSA). By screening a set of 978 EST-SSRs and 395 SSRs, a marker BoE332 linked to the CDMs399-3 at a distance of 3.6 cM in the genetic background of cabbage line 397 were identified. 7 homozygous male-sterile plants in population P1170 with 20 plants were obtained finally via MAS of BoE332. Thus, BoE332 will greatly facilitate the transferring of the gene CDMs399-3 into the key spring cabbage line 397 and improve the application of DGMS in cabbage hybrid breeding.

To obtain transgenic cabbage line with broad insect resistance, a new synthetic Bacillus thuringiensis cry1Ba3 gene was introduced into white cabbage via Agrobacterium tumefaciens-mediated transformation and 37 transformants were obtained. Polymerase chain reaction (PCR) and Southern blot analyses confirmed that cry1Ba3 was successfully inserted into the genome of cabbage. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that cry1Ba3 was expressed. Western blot results confirmed the production of insecticidal protein encoded by cry1Ba3. Insect bioassays showed that transgenic cabbages effectively controlled both susceptible and Cry1Ac-resistant diamondback moth (DBM) larvae.