国产黄连属植物的染色体核型分析

中国黄连属6种1变种分属叶掌状三全裂和叶掌状五全裂2个类群,前者包括三角叶黄连、峨眉黄连、云南黄连、黄连和其变种短萼黄连;而分布于滇东南的五裂黄连和产于台湾的五叶黄连则归于后者。采用根尖压片法和卡宝品红染色法,对除五叶黄连外的中国黄连属5种1变种,以及日本黄连进行染色体核型比较分析,从细胞学角度为探讨中国黄连属植物的系统分类提供新的线索和证据。结果表明:(1)五裂黄连(2n=2x=18=2M+16m)、短萼黄连(2n=2x=18=8m+10sm)和日本黄连(2n=2x=18=12m+6sm)的染色体数目和核型均为首次报道。(2)7个材料的染色体基数均为9,除三角叶黄连为三倍体外,其余均为二倍体。(3)叶为掌状三全裂的二倍体种核型一致,为2A型,染色体类型以及不对称系数均很相似;叶为掌状五全裂的五裂黄连与五叶黄连的核型更接近,为1A型,核型特征的共性表明了这2个类群的自然属性。(4)三倍体三角叶黄连的不对称程度较高,核型为3A型,其染色体大小与峨眉黄连最接近。(5)根据核型不对称程度和染色体大小,结合地理分布,推测叶掌状五全裂种为本属的原始类群。

Chromosome Karyotypes of Coptis Species in China

Coptis Salisb.in China is divided into 2 groups by morphology of leaf according to Flora of China.The group with three all splited palmate leaves includes 4 species and 1 variety,which are Coptis deltoidea,C.omeiensis,C.teeta,C.chinensis and its variety C.chinensis var.brevisepala.C.quinquesecta scattered in Southeast Yunnan and C.quinquefolia distributed only in Taiwan belong to the group with five all splited palmate leaves.By using the methods of root tip squash and carbol fuchsin dyeing,we investigated the chromosome numbers and karyotypes of 5 species and 1 variety except C.quinquefolia of this genus in China,as well as C.japonica.The results are as follows:(1)The chromosome numbers and karyotypes of C.quinquesecta,C.chinensis var.brevisepala and C.japonica are reported for the first time.(2)In this genus,the basic chromosome number is x=9.Except for triploid of C.deltoidea,all others are diploids.(3)The karyotypes of all diploid species and variety of the group with three all splited palmate leaves belong to 2A type.They have similar metaphase chromosomes.In the group with five all splited palmate leaves,the karyotypes of the 2 species belong to 1A type,and the karyotypical features of the 2 species are more similar,and the sizes of chromosome are smaller than the ones of the species in another group.The similar karyotypical features support the viewpoint that the 2 groups are natural taxa respectively.(4)The degree of asymmetry of the karyotype of C.deltoidea is the highest in these 6 species and 1 variety,and its karyotype belongs to 3A type.According to the sizes of chromosomes and the geographical distribution,it is proposed that C.deltoidea be derived originally from C.omeiensis.(5)According to the asymmetric degree of the karyotype and the sizes of chromosomes,the group with five all splited palmate leaves is considered as a primitive taxon in the genus.