不同生态区云南黄连居群的染色体核型比较

Comparative Analysis on the Chromosome Karyotypes of Coptis teeta Populations of Yunnan in Different Ecological Areas

采用根尖压片和卡宝品红染色法,对分布于高黎贡山的东、西坡不同生态带的8个云南黄连居群进行染色体核型比较分析。结果表明,8个居群染色体数目均为2n=2x=18,核型基本一致,除东坡一个居群为3A型外,其余均为2A型;总体上同一生态区域内各居群的核型表现出较大的相似性,但不同生态区域的居群间却存在较大的差异,主要为近端部和端部着丝点染色体的有无及数目在东西坡居群间存在较大变化;东坡居群的不对称程度均较西坡高。

The karyotypes of 8 populations of Coptis tecta,which distributed in different ecological areas （4 in east slope and the other 4 in west slope of Mt. Gaoligong） ,were studied using the methods of root tip squash and carbol fuchsin dyeing. The results show as follows. （1） In these populations, the chromosome numbers are same 2n=2x=18;（2）Except that the karyotype of one population in east slope belongs to 3A type,the karyotypes of rest 7 populations belong to 2A type~ （3）Despite the fact that the karyotypical fea- tures appear to be similar for the populations in the same ecological area （i. e. east slope or west slope）, large karyotypical differences exist among those populations in different ecological areas. First, the occur- rence and numbers of acrocentric chromosomes （st chro. ） and telocentric chromosomes （t chro. ） are varia- ble among the populations in the east and west slope. Second, the degrees of karyotype asymmetry of the populations in east slope are higher than those of the populations in west slope.