小毛茛居群的遗传分化及其与空间隔离的相关性  

Genetic differentiation and the relation to spatial isolation among populations of Ranunculus ternatus

作　　者：汪小凡[1] 廖万金[2] 宋志平[3] 

机构地区：[1]武汉大学植物发育生物学教育部重点实验室,武汉430072 [2]北京师范大学生物多样性与生态工程教育部重点实验室,北京100875 [3]武汉大学生命科学学院,武汉430072

出　　处：《生物多样性》2001年第2期138-144,共7页Biodiversity Science

基　　金：国家自然科学基金!项目 ( 3 9870 0 82 );教育部骨干教师资助!项目资助

摘　　要：采用聚丙烯酰胺凝胶电泳技术 ,对分布于华中地区的 11个小毛茛 (Ranunculusternatus)居群的遗传分化进行了检测。对 8个酶系统 17个酶位点上的分析结果表明 ,该种各居群的各项遗传多样性指标处于一个相对较低的水平 :多态位点比率 (P)为 0～ 5 3.0 % ,平均每位点等位基因数 (A)为 1～ 1.6 47,平均预期杂合度 (He)和观察杂合度 (Ho)分别为 0～ 0 .10 8和 0～ 0 .10 2。居群间遗传一致度甚高 (I =0 .975 4～ 0 .9991)。根据Nei′s遗传距离所作出的聚类分析表明 ,豫南信阳地区 3个居群与湖北省武汉地区 8个居群之间关系较远。而在武汉地区 ,长江以北的居群及长江以南的部分居群分别相聚在一起。用GPS定位方法得到居群间空间距离并据此聚类 ,结果显示了该种的遗传分化与地理因素的相关性 ,并推测出长江的隔离作用加强了两岸居群间的遗传分化。同时发现一个生于独特生境的居群在表型和遗传结构上都已与其他邻近居群有了很大分异 ,由于该居群在所检测的酶位点上均无特有等位基因出现 。Genetic differentiation of 11 populations in Ranunculus ternatus Thunb. from Central China was detected by means of PAGE. Eight enzymes encoded by seventeen loci were assessed. Genetic diversity within populations was relatively low. The proportion of polymorphic loci (P) ranged from 0 to 41.2%, the average number of alleles per locus (A) from 1 to 1.647, the mean expected and observed heterozygosity (He, Ho) per locus were from 0 to 0.108 and 0 to 0.102 respectively. The genetic identities between populations were remarkably high (I=0.9754～0.9991). According to the results of cluster analysis based on Nei′s genetic distances, three populations distributed in the southern part of Henan Province were far from the populations in Wuhan, Hubei Province. In Wuhan, very high similarity appeared among populations situated north of the Yangtze River (Changjiang), and among those on the area south of the river. Analysis based on the spatial distance measured by GPS indicated a relationship between genetic distances and geographical factors. The authors deduced that the genetic differentiation of populations was enhanced by the isolating effect of the Yangtze River. A population from Wuhan was found to be remarkably different from the others in both morphological characters and genetic structures. But this population was not suggested as a new species or a new variety because no unusual allele was found in the enzyme loci detected.

关 键 词：小毛莨 遗传分化 遗传距离 植物居群 空间隔离 相关性 

分 类 号：Q346[生物学—遗传学] Q949.746.5