Genetic divergence of intraspecific aneuploids in Carex conica.

对日本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，分别为2n=32、33、34、35、36、37和38。二倍体染色体数目为2n=32、34和36的植株最多见，地理分布不同。用9种酶系统的电泳法分析了4种非整倍体锥栗(2n=32、34、36和38)的遗传分化。采用水平聚丙烯酰胺凝胶电泳法。对9个酶系统的10个可解释基因座进行评分。计算每个群体的等位酶频率。根据等位基因频率计算了17个群体的遗传距离(Nei，1972)。利用NJ法和Fitch-Margoliash法对群体间的遗传距离进行聚类分析，以确定群体间的亲缘关系。识别出4个类群：(1)来自后藤内海沿海地区的2n=32个；(2)来自日本本州东部的2n=34个；(3)来自中部、四国和九州山区的2n=36个；(4)来自？木县的2n=38个。2n=36的20个居群(0.113)和2n=34的24个居群(0.099)的种内遗传距离较大，而2n=32的14个居群(0.039)和2n=38的2个居群(0.030)的种内遗传距离较低。这些结果表明，在最近的物种分化中，2n=32和2n=38植物已经分化。

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.