二倍体及同源四倍体不结球白菜核型分析

Karyotype analysis of diploid and autotetraploid non-heading Chinese cabbage

以二倍体不结球白菜及其同源四倍体为材料,采用常规染色压片法进行核型分析。结果表明:二倍体不结球白菜核型公式为2n=2x=20=10m+8sm(2SAT)+2st,其中第1、2、3、4、6对为中着丝粒染色体,第5、7、8、9对为近中着丝粒染色体,第10对为近端着丝粒染色体,第5对染色体具有随体,核型类型属于2A型,为基本对称型;四倍体不结球白菜核型公式为2n=4x=20m+16sm(4SAT)+4st,核型特征与二倍体基本一致,仅染色体长度变异范围与二倍体相比略大。表明四倍体不结球白菜是由其二倍体加倍得到的,为同源四倍体。

The diploid and tetraploid non-heading Chinese cabbage were used to make karyotype study by conventional squash method.The results showed that the diploid non-heading Chinese cabbage karyotype formula was 2n=2x=20=10m＋8sm（2SAT）＋2st,with 5 pairs metacentric chromosomes（1,2,3,4,6）,4 pairs submetacentric chromosomes（5,7,8,9）,and 1 pairs subtelocentric chromosome,and all of two satellites appeared at fifth pairs chromosomes.The karyotye belonged to 2A,with ultimately symmetry karyotype.In addition,the tetraploid non-heading Chinese cabbage karyotype formula was 2n=4x=20m＋16sm（4SAT）＋4st,the same as diploid.It is proved that tetraploid non-heading Chinese cabbage was autotetraploid of diploid.