Mating pattern of a distylous primrose in a natural population: unilateral outcrossing and asymmetric selfing between sexual morphs
Mating pattern of a distylous primrose in a natural population: unilateral outcrossing and asymmetric selfing between sexual morphs
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DOI：
10.1007/s10682-018-9965-0
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发表时间：
2018-11
影响因子：
1.9
通讯作者：
Kurumi Arima;D. Kyogoku;N. Nakahama;K. Suetsugu;M. Ohtani;Chiyo Ishii;H. Terauchi;Y. Terauchi
中科院分区：
文献类型：
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作者：
Kurumi Arima;D. Kyogoku;N. Nakahama;K. Suetsugu;M. Ohtani;Chiyo Ishii;H. Terauchi;Y. Terauchi
异质花柱是花药和柱头高度的遗传多态性，它们在形态中相互放置。异质型的维持通常归因于非分类交配，但也可能有其他解释，可以通过分析交配模式来检验。然而，尽管异花柱物种具有系统发育多样性，但用遗传标记进行亲本分析只应用于有限数量的分类群。本文利用11个微卫星标记，研究了二瓣报春花Primula kisoana（报春花科）在其自然栖息地的交配模式。我们还研究了其他健身成分。我们发现变种之间在种子产量、营养生长或存活方面没有差异。然而，长针父亲的配种成功率远高于针父亲；短秆父系与短秆母系单侧异交发生，短秆自交较短秆自交频繁。这些发现与解释一致，即在该物种中，由于先前报道的线头等位基因的隐性致死效应，通过显性或在近亲繁殖抑制强烈的情况下通过有效的雌雄异株交配来维持distyly。我们为优势假设建立了一个数学模型，以证实它在逻辑上是合理的。这些结果为进一步研究显性和雌雄异株在维持异质柱中的可能作用提供了依据。
Heterostyly is a genetic polymorphism of anther and stigma heights, which are reciprocally placed among morphs. The maintenance of heterostyly has often been ascribed to disassortative mating, but alternative explanations are also possible, which can be examined by analyzing mating patterns. However, parental analysis with genetic markers has only been applied to a limited number of taxa, despite the phylogenetic diversity of heterostylous species. Here, we examined the mating patterns of a distylous primrose,Primula kisoana(Primulaceae), in its natural habitat, using 11 microsatellite markers. We also examined other fitness components. We found no differences in seed production, vegetative growth, or survival between morphs. However, the siring success of thrum fathers was much higher than that of pin fathers; outcrossing occurred unilaterally between thrum fathers and pin mothers, and selfing was more frequent in thrum plants than in pin plants. These findings are consistent with the explanation that distyly in this species is maintained either by overdominance due to previously reported recessive lethal effects of the thrum allele or by effectively dioecious mating if inbreeding depression is strong. We built a mathematical model of the overdominance hypothesis to confirm that it is logically sound. These results warrant further investigations into the possible roles of overdominance and dioecy in the maintenance of heterostyly.