中国几种棘蛙的核型C—带和Ag—NORs研究

THE STUDY ON THE KARYOTYPES, C-BANDING AND AG-NORs OF FOUR Paa SPECIES IN CHINA

本文对４种棘蛙的核型、Ｃ－带和Ａｇ－ＮＯＲｓ作了观察分析，结果表明无声囊棘蛙Ｚｎ＝６４Ｔ，Ａｇ－ＮＯＲｓ在２０ｑｉｎｔｅｒ，全部着丝点区域Ｃ－带正染。云南的棘腹蛙、察隅棘蛙和河南太行山隆肛蛙３者，其２ｎ＝２６，５＋８模式，但相互间ＳＭ的对数和顺序有所不同；前二者的Ａｇ－ＮＯＲｓ均在６ｐｐｅｒ，但Ｃ－带有很大的不同：察隅棘蛙的着丝点Ｃ－带浅染，但有较多的端部和居间型Ｃ－带。隆肛蛙的Ａｇ－ＮＯＲｓ在１２ｐｐｅｒ，除了较浅的全部着丝点Ｃ－带外，在少数染色体上有很浓的端部和居间型Ｃ－带。４种均未发现异形性染色体。最后还对棘蛙的核型演化机制作了讨论。

The Karyotypes, C-banding and Ag-NORs of four Anuran poa species in China. have been investigated here. The results are as follows: Paa lint 2n=64T, all the centromeric regions have C-positive staining and Ag-NORs localized on 20q, inter. Paa boulengeri and P.chayuensis both from Yunnan and P. quadrana from mount Taihang in Henan Province have 2n=26 consisted of SM or M and 5+8 formulae commonly, but the count and sequence of SM between them showed some dissimilarities. For the former two there are same 6p per Ag-NORs locations, but more differences are found in C-bands: some terminal and interstitial C-bands presented in P. chayuensis, but light staining in centromeric regions. And in the latter-Paa quadrana there are more dense interstitial and terminal C-bands in some pairs except in centromeric ones that are less developed. No heteromorphic sex chromosomes occured in four species studied.Finally the comparison and analysis of karyotypes and banding pattern and evolution way between species and geographical populations are discussed.