A Comparative Study on The Karyotype of Three Species in Phrynocephalus (Agamidae)

The karyotypes of Phrynocephalus alboineatus,P.grumgrizimaloi and P.theobaldi were reported used by the method of chromosome preparation directly of marrow cells.P.theobaldi had 2 n=22I+26 m with NF=48,the others had 2 n=22I+24 m with NF=46.The karyotypes of three species were compared with those of other species in the same genus.It was speculated that there were at least two karyotype-group in Phrynocephalus,furthermore,the existence of two karyotype-group was possibly associated with the hypothesis given by Ananjeva in 1992 of two originating centers of Phrynocephalus.The species originated from "Central Asia" center mostly belong to the first karyotype-group having 2 n=46=22I+24 m with NF=46 whereas those from 2 "Middle Asia" Center belong to the second karyotype-group having 2 n=48=22I+26 m with NF=48.The tendency of karyotype evolution in Phrynocephalus was discussed.It was considered the ancients of Phrynocephalus having karyotype,2n=48,then changed and divided to two karyotype-branch,2n=46 and 2n=48.Among them,P.grumgrizimaloi,P.helioscopus,P.axillaris,P.versicolor and P.mystaceus were the derivated species.The difference between the karyotypes of the two populations in P.grumgrizimaloi was possibly revealed the geographical divergence of their genetic construction.The karyotypes of Phrynocephalus genus comparing with other genera in Agamidae proved the primitive taxonomical position in the family.