Chromosomal karyotypes in root tip cells of Pternopetalum botrychioides (Dunn) Hand.-Mazz. and P. latipinnulatum (Shan) J. B. Tan et X. J. He in Pternopetalum Franch. of Apiaceae were analyzed by using pressing flake method. The results show that chromosome length of P. botrychioides and P. latipinnulatum is 2.60-4.89 and 2.97-4.42 μm, respectively, and total length of their genome is 117.60 and 122.06 μm, respectively; their chromosome numbers are both 33, basic chromosome numbers are both x=11, karyotype formulas are both 2n=3x=21m+9sm+3st, and karyotype asymmetries are both 2A type. The significance of classification and basic chromosome number of P. botrychioides and P. latipinnulatum in grouping of species in Pternopetalum is discussed based on the research results. |