云南三种同域分布的棘蛙（蛙科Ranidae：无尾目Anura）的核型和银带研究

本文比较分析了云南景东地区三种同域分布棘蛙的核型和Ａｇ－ＮＯＲｓ。花棘蛙２ｎ＝２６（１６Ｍ＋ １０ＳＭ），ＮＦ＝５２，次缢痕和Ａｇ－ＮＯＲｓ位于１ｐｉｎｔｅｒ，Ｎｏｓ．２－４，８，９等为ＳＭ。棘肛蛙２ｎ＝４０（１６Ｍ＋ ２０ＳＭ＋２ＳＴ＋２Ｔ），ＮＦ＝７８，Ｎｏｓ．５－９，１１－１３，１５，１７等１０对为ＳＭ，Ｎｏ．３为ＳＴ，Ｎｏ．１８为Ｔ，其余 均为Ｍ，Ａｇ－ＮＯＲｓ位于１１Ｐ。二种的Ａｇ－ＮＯＲｓ都有异形现象。双团棘胸蛙２ｎ＝６４Ｔ，次缢痕和Ａｇ－ ＮＯＲＳ在４ｑｐｅｒ。都未发现异形性染色体。最后，对棘蛙属的核型演化机制和物种形成方式作了讨论。

ON THE KARYOTPES AND Ag-NORS OF THREE SYMPATRICALLY PAA FROGS IN YUNNAN PROVINCE

This paper deals with the results of the investigation on the karyotypes and Ag-NORs of three Paa species of frog distributed sympatrically in Jingdong County of Yunnan Province. The results showed that Paa muculosa has the chromosome of 2n = 26 (16M + 10SM ). NF = 52. The secondary constriction (SC) and Ag-NORs are on the interstitial region of short arm of the first pair chromosome,the frequency of SC is 90%,Nos. 2,3,4, 8, 9,are SM. The rests are M. Paa unculuana has the chromosome of 2n=40(16M+20SM +2ST+2T),NF=78. Nos. 5- 9, 11-13, 15, 17 are SM and No. 3 is ST, NO. 18 is T and the rests are M. The Ag-NORs located at short arm of the eleventh pair. The heteromorphism of Ag-NORs existed in both two species. P. phrynoides 2n=64T,SC and Ag-NORs are on peripherical region of the long arm of the fourth pair. Based on comparative materials of known Paa karyotypes, the evolutionary mechanism of the karyotype and the mode of speciation have been discussed. No relationship between the heteromorphism of chromosome and the sexuality in three examined species of frog could be found.