Abstract: Interspecific hybridization between Brassica species is an important way to create new resources and combine the valuable characters of different species, which is widely used in plant breeding. 120 plants of triploid hybrid (ABC, n=27) derived from cross between B. carinata (BBCC, 2n=34) and B. rapa(AA,2n=20)was obtained which played a important role in creating bridge materials for other Brassica species with one or two of the three genomes, 80% of the hybrid plants had expected 27 chromosomes and showed intermediate characteristics. RAPD markers also verified the true hybrid nature. Two waye were used for chromosome doubling, one was that the 0.05% colchicine aolution was dropped on the growing point, another was that the seedlings were dipped into the 0.05% colchicine solution for 8 hours, the ratio for chromosome doubling varied much between two methods.... ...

Key words: Interspecific crossing, Brassica carinata, Chromosome doubling, Physiological and biochemical analysis