观察分析了中山杉401无性系(Taxodium ascendens Brongn×Taxodium mueyonatum Tenore CL’401’)的染色体核型,并与亲本的染色体核型进行了比较。结果表明,中山杉401无性系的染色体数目为2n=22,核型公式为K(2n)=20m+2sm。杂种后代有两条大小、形态不同的近中部着丝点染色体,一条为第11条,一条为第17条,仅第17条具大着丝点的特征。中山杉401无性系确系种间杂种,在该无性系中未发生染色体加倍、缺失的变异。 The chromosome karyotypes of Taxodium ascendens Brongn × Taxodium mueyonatum Tenore CL’401 ’were observed and analyzed and compared with the parental karyotypes. The results showed that the chromosome number of Zhongshan 401 was 2n = 22 and its karyotype was K (2n) = 20m + 2sm. Hybrid offspring have two sizes, different morphological near centromere chromosomes, one for the first 11, one for the first 17, only the first 17 features a large centromere. Zhongshan fir 401 clonal hybrid interspecific hybrids, in the clonal chromosome doubling, missing mutation.