An improved chromosome preparation method was used to study the karyotypes of Brassica napus and Brassica juncea. The results indicated that both chromosome numbers and karyotypic symmetry were stable in the cultivars of two species analysed, comparing with the reports of other authors published previously. The karyotype formulae of B. napus cv. Zhongshuang 4 was 2n=4x=38=2 M + 22 m + 14 sm, and that of B. juncea cv. Wangjiangliangting was 2n=4x=36=24 m + 8 sm (2SAT) + 4st. The karyotypes of two cultivars all belong to 2B type in karyotypic classification. The differences of the karyotypes wit...
