2个西藏白菜型油菜地方品种的核型分析及比较

Difference on Karyotype Analysis of 2 Local Rape Varieties(Brassica rapa L.)in Tibet

为研究2个西藏白菜型油菜褐籽品种"嘎壤油菜"和黄籽品种"雪巴黄籽油菜"的细胞学信息,采用常规压片法进行核型分析及比较,结果表明:2个西藏白菜型油菜的染色体数目均为2n=20,二倍体,均由中部着丝粒和亚中部着丝粒染色体组成,有1对中部着丝粒染色体带有随体;染色体组成结构、核型参数具有一定的差异,褐籽品种的核型参数均大于黄籽品种。褐籽品种"嘎壤油菜"进化程度较高,为中间类型2B型,黄籽品种"雪巴黄籽油菜"的进化程度较低,较为原始,为对称类型1A型。

In order to study cytological information of 2 local rape lines （Brassica rapa L.） in tibet, which included brown-seed rape ＂Garang rape＇and yellow-seed rape ＂Xuba yellow-seed rape＂, karyotype analysis was conducted by using conventional tableting observation. Results showed that 2 local rape lines （Brassica rapa L.） from Tibet Chi- na had 20 chromosomes composed by median region chromosomes （m） and submedian region chromosomes （sm） , and the median region chromosomes （m） with a pair of satellites. The morphology of chromosome and karyotypic pa- rameters had some differences, the karyotypic parameters of brown-seed rape were more than these of yellow-seed rape.We found that the evolutionary rate of brown-seed rape＂Garang rape＇was higher, belonging to the 2B type, and the evolutionary rate of yellow-seed rape ＂Xuba yellow-seed rape＂ was lower, the line kept at the original position in evolution process, which belonged to the 2B type.