Patterns, sources and ecological implications of clonal diversity in apomictic Ranunculus carpaticola (Ranunculus auricomus complex, Ranunculaceae)
Patterns, sources and ecological implications of clonal diversity in apomictic Ranunculus carpaticola (Ranunculus auricomus complex, Ranunculaceae)
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DOI：
10.1111/j.1365-294x.2006.02800.x
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发表时间：
2006-04
影响因子：
4.9
通讯作者：
O. Paun;J. Greilhuber;E. Temsch;E. Hörandl
中科院分区：
文献类型：
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作者：
O. Paun;J. Greilhuber;E. Temsch;E. Hörandl
无性生殖复合体中遗传多样性的来源和影响仍在争论中。采用群体研究(扩增片段长度多态、微卫星)和核学方法(Feulgen DNA图像密度仪和流式细胞术)对斯洛伐克中部10个种群的遗传多样性和倍性水平进行了研究。尽管两个二倍体群体表现出高度的遗传多样性，正如有性繁殖所预期的那样，但有八个群体是六倍体，具有较低程度的基因变异，但在许多座位上保持着高水平的杂合度，这在无融合生殖中是典型的。多倍体群体由单一AFLP基因型或一种显性和少数偏离型组成。基因型/基因变异和性状不亲和性分析表明，无融合生殖群体内的基因变异是由突变引起的，但在一个群体中可能也是由重组引起的。这种地方兼性行为可能会对地区基因多样性产生很大影响。两个微卫星座位通过在每个AFLP克隆中积累较少的突变(克隆配对)来区分分离的基因型。遗传多样性主要分布在无融合生殖种群中，没有地理结构，这可能是由于兼性繁殖和/或不同无性系对地点的多次殖民造成的。无融合生殖种群的生境分化和栖息于人工草地的趋势比有性种群更为明显。我们推测，在时间和空间上的异质性环境中维持无融合生殖细胞的遗传多样性和优越的定殖能力对它们的分布成功是重要的。
Sources and implications of genetic diversity in agamic complexes are still under debate. Population studies (amplified fragment length polymorphisms, microsatellites) and karyological methods (Feulgen DNA image densitometry and flow cytometry) were employed for characterization of genetic diversity and ploidy levels of 10 populations of Ranunculus carpaticola in central Slovakia. Whereas two diploid populations showed high levels of genetic diversity, as expected for sexual reproduction, eight populations are hexaploid and harbour lower degrees of genotypic variation, but maintain high levels of heterozygosity at many loci, as is typical for apomicts. Polyploid populations consist either of a single AFLP genotype or of one dominant and a few deviating genotypes. genotype/genodive and character incompatibility analyses suggest that genotypic variation within apomictic populations is caused by mutations, but in one population probably also by recombination. This local facultative sexuality may have a great impact on regional genotypic diversity. Two microsatellite loci discriminated genotypes separated by the accumulation of few mutations (‘clone mates’) within each AFLP clone. Genetic diversity is partitioned mainly among apomictic populations and is not geographically structured, which may be due to facultative sexuality and/or multiple colonizations of sites by different clones. Habitat differentiation and a tendency to inhabit artificial meadows is more pronounced in apomictic than in sexual populations. We hypothesize that maintenance of genetic diversity and superior colonizing abilities of apomicts in temporally and spatially heterogeneous environments are important for their distributional success.