Geographic pattern of genetic variation in the European globeflower Trollius europaeus L. (Ranunculaceae) inferred from amplified fragment length polymorphism markers
Geographic pattern of genetic variation in the European globeflower Trollius europaeus L. (Ranunculaceae) inferred from amplified fragment length polymorphism markers
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DOI：
10.1046/j.1365-294x.2002.01618.x
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发表时间：
2002-11-01
影响因子：
4.9
通讯作者：
Gaudeul, M
中科院分区：
文献类型：
--
作者：
Despres, L;Loriot, S;Gaudeul, M
利用AFLP显性标记分析了高山植物金莲花在阿尔卑斯山、比利牛斯山和芬诺斯坎迪亚3个主要地区的18个种群间的遗传变异分布和系统发育关系。分子方差分析表明，大部分遗传变异发生在种群内(%)，但区域间(17%)和区域内种群间(19%)的遗传变异极显著(P<；0.001)。因此，基因座上的整体注视指数F-ST很高(0.39)。种群间的分化表明基因流动受到限制，这与特定传粉蝇(Chiastocheta spp.)的有限扩散相一致。阿尔卑斯山(平均Nei‘s期望杂合度H-E=0.229)的种群内多样性水平显著高于比利牛斯山(H-E=0.197)或芬诺斯坎迪亚(H-E=0.158)。这一发现与相关苍蝇的物种丰富程度是一致的，在阿尔卑斯山最丰富。我们讨论了在欧洲锥虫种群内和种群之间形成观察到的遗传多样性模式所涉及的过程。遗传漂移是作用于欧洲锥虫分布南缘的小比利牛群的主要因素，而大的芬诺斯坎迪亚种群可能是创始人效应和人口扩张的结果。阿尔卑斯山种群代表了大量南方祖先种群的适度碎片化的遗迹。在寄主植物中观察到的遗传变异模式支持共生果蝇同域物种形成的假说，而不是反复出现的异地物种。
The distribution of genetic variation and the phylogenetic relationships between 18 populations of the arctic-alpine plant Trollius europaeus were analysed in three main regions (Alps, Pyrenees and Fennoscandia) by using dominant AFLP markers. Analysis of molecular variance revealed that most of the genetic variability was found within populations (64%), although variation among regions (17%) and among populations within regions (19%) was highly significant (P < 0.001). Accordingly, the global fixation index F-ST averaged over loci was high (0.39). The among-population differentiation indicates restricted gene flow, congruent with limited dispersal of specific globeflower's pollinating flies (Chiastocheta spp.). Within-population diversity levels were significantly higher in the Alps (mean Nei's expected heterozygosity H-E = 0.229) than in the Pyrenees (H-E = 0.197) or in Fennoscandia (H-E = 0.158). This finding is congruent with the species-richness of the associated flies, which is maximum in the Alps. We discuss the processes involved in shaping observed patterns of genetic diversity within and among T. europaeus populations. Genetic drift is the major factor acting on the small Pyrenean populations at the southern edge of T. europaeus distribution, while large Fennoscandian populations result probably from a founder effect followed by demographic expansion. The Alpine populations represent moderately fragmented relics of large southern ancestral populations. The patterns of genetic variability observed in the host plant support the hypothesis of sympatric speciation in associated flies, rather than recurrent allopatric speciations.