Karyotypes of Two Species of Cycas from China
两种国产苏铁属植物的核型分析

Chromosome numbers and of the two Cycas species from China are all 2n=2x=22,and the karyotypes are classified to be 3B according to stebbin's category.The karyotype formulas are 2n=2x=22=4m+2sm+4st+12T for C.hainanensis,and 2n=2x=22=2m+4sm+4st+12T for C.szechuanensis subsp.fairylakea.The two karyotypes are reported for the first time.The results support that Cycas can be divided into two groups based on the chromosome data.