GENETIC ORGANIZATION AND EVOLUTIONARY HISTORY IN TWO NORTH AMERICAN SPECIES OF CIRSIUM
GENETIC ORGANIZATION AND EVOLUTIONARY HISTORY IN TWO NORTH AMERICAN SPECIES OF CIRSIUM
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北美两种锔的遗传组织和进化历史
DOI：
10.1111/j.1558-5646.1988.tb04130.x
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发表时间：
1988
期刊：
影响因子：
3.3
通讯作者：
J. Hamrick
中科院分区：
文献类型：
--
作者：
M. D. Loveless;J. Hamrick
涉及祖先和衍生物种对的关系已经在一些植物分类群中被记录下来。在这项研究中，我们使用淀粉凝胶电泳法研究了限制在五大湖海岸线上的一种特有的蓟，以及与大平原中部(美国)有密切关系的一种蓟之间的可能关系。这些物种具有相同的酶基因座，但在遗传多样性水平上存在很大差异。狗尾草的遗传变异远低于其同类，具有较少的多态座位和显著较低的杂合度。狗尾草的遗传变异代表了狗尾草中存在的等位基因的一个退化子集，这与两个物种代表祖先-衍生物种对的假设是一致的。我们认为，在威斯康星州冰川末期，狗尾草迁徙到了大湖区新形成的沙丘栖息地，它的低遗传变异性是伴随着它的移动而反复出现的、可能是长期的种群瓶颈所致。
Relationships involving progenitor and derivative species pairs have been documented for a number of plant taxa. In this study, we used starch‐gel electrophoresis to examine the probable relationship between Cirsium pitcheri, an endemic thistle restricted to the shorelines of the Great Lakes, and Cirsium canescens, a closely related species of the central Great Plains (U.S.A.). The species shared the same enzyme loci but differed greatly in levels of genetic diversity. C. pitcheri was genetically much less variable than its congener, with fewer polymorphic loci and significantly lower heterozygosity. The genetic variation in C. pitcheri represents a depauperate subset of the alleles present in C. canescens, consistent with the hypothesis that the two species represent a progenitor‐derivative species pair. We suggest that C. pitcheri migrated into newly created dune habitats in the Great Lakes region near the end of the Wisconsin glaciation and that its low genetic variability results from repeated and probably prolonged population bottlenecks which accompanied its movement.