Genetic divergence of intraspecific aneuploids in Carex conica.

对来自日本146个居群的1556株圆锥苔草进行了染色体数目测定。共发现7个非整倍体，2n= 32、33、34、35、36、37和38，其中偶数倍体2n= 32、34和36的植株最多，且具有不同的地理分布。采用9种酶系的电泳分析方法，对圆锥锦鸡儿4个非整倍体（2n= 32、34、36和38）的遗传分化进行了研究。水平聚丙烯酰胺凝胶电泳。对9种酶系统的10个可解释的位点进行评分。计算每个群体的等位酶频率。用Nei（1972）的方法计算了17个群体间的遗传距离。利用NJ法和Fitch-Margoliash法对群体间的遗传距离进行聚类分析，确定了群体间的亲缘关系。结果表明：（1）2n=32，分布于濑户内海沿岸;（2）2n=34，分布于本州东部;（3）2n=36，分布于中国、四国和九州山区; 2n=36的20个居群和2n=34的24个居群的种内遗传距离较高（分别为0.113和0.099），而2n=32的14个居群和2n=38的2个居群的种内遗传距离较低（分别为0.039和0.030）。这些结果表明，2n=32和2n=38的植物已分化在最近的物种形成。

Chromosome numbers were determined for 1556 plants of Carex conica from 146 populations in Japan. Seven aneuploids, 2n=32,33,34,35,36,37 and 38, were found. Plants with even diploid chromosome numbers 2n=32,34 and 36 were the most common and had different geographical distributions. Genetic divergence was examined in the four aneuploids of C.conica (2n=32,34,36 and 38) by electrophoretic analysis of nine enzyme systems. Horizontal polyacrylamide gel was used for electrophoresis. Ten interpretable loci were scored for nine enzyme systems. Allozyme frequencies were calculated for each population. Genetic distances (Nei, 1972) among 17 populations were calculated from the allele frequencies. Relationships among populations were determined by clustering the genetic distances using NJ and Fitch-Margoliash methods. Four clusters were recognized : (1) 2n=32 from coastal areas of Seto Inland Sea, (2) 2n=34 from eastern Honshu of Japan, (3) 2n=36 from the mountainous areas of Chugoku, Shikoku and Kyushu, (4) 2n=38 from Tochigi Prefecture. Intraspecific genetic distances among 20 populations of 2n=36 (0.113) and 24 of 2n=34 (0.099) were relatively high, but 14 of 2n=32 (0.039) and two of 2n=38 (0.030) were low. These results suggested that 2n=32 and 2n=38 plants have been differentiated in recent speciation.