POLLINATOR SPECIFICITY DRIVES STRONG PREPOLLINATION REPRODUCTIVE ISOLATION IN SYMPATRIC SEXUALLY DECEPTIVE ORCHIDS
POLLINATOR SPECIFICITY DRIVES STRONG PREPOLLINATION REPRODUCTIVE ISOLATION IN SYMPATRIC SEXUALLY DECEPTIVE ORCHIDS
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传粉者特异性导致同域性欺骗兰花中强烈的授粉前生殖隔离
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. Peakall
中科院分区：
文献类型：
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作者：
M. R. Whitehead;R. Peakall
很少有研究量化了限制近缘植物物种间渗透的合子前和合子后障碍的全部范围。在这里，我们评估了四种隔离机制在两个形态相似且关系非常密切的共生兰科植物间的作用强度，这两个共域兰花分类群是Chiloglottis valida和C.aff。杰内西。每个分类单元通过不同的花的挥发性化学物质吸引其特定的黄蜂传粉者。用花和合成版本的花的挥发物进行的行为实验证实，非常强烈的传粉者隔离是由花的气味化学介导的。然而，人工将这两个分类群的花放置在接触的附近，揭示了罕见的种间授粉的可能性。虽然我们在通过手工杂交产生的F1代中发现了杂种优势，但核基因和叶绿体基因座的遗传分析都显示出类群之间显著的和中到强的遗传分化。用贝叶斯聚类法检测核基因座的渗入，没有发现任何证据表明在一个共生位点上有571个独特的基因类型进行杂交。这里调查的授粉后障碍非但没有抑制基因流动，反而没有对整体生殖隔离做出任何贡献。这证明了传粉者在维持这些兰花物种边界方面的首要地位，这些兰花展示了已知的授粉前花隔离的最强例子之一。
Few studies have quantified the full range of pre‐ and postzygotic barriers that limit introgression between closely related plant species. Here, we assess the strength of four isolating mechanisms operating between two morphologically similar and very closely related sympatric orchid taxa, Chiloglottis valida and C. aff. jeanesii. Each taxon sexually attracts its specific wasp pollinator via distinct floral volatile chemistry. Behavioral experiments with flowers and synthetic versions of their floral volatiles confirmed that very strong pollinator isolation is mediated by floral odor chemistry. However, artificially placing flowers of the two taxa in contact proximity revealed the potential for rare interspecific pollination. Although we found hybrid vigor in F1 hybrids produced by hand‐crossing, genetic analysis at both nuclear and chloroplast loci showed significant and moderate‐to‐strong genetic differentiation between taxa. A Bayesian clustering method for the detection of introgression at nuclear loci failed to find any evidence for hybridization across 571 unique genotypes at one site of sympatry. Rather than inhibiting gene flow, postpollination barriers surveyed here show no contribution to overall reproductive isolation. This demonstrates the primacy of pollinators in maintaining species boundaries in these orchids, which display one of the strongest known examples of prepollination floral isolation.
影响因子：
3.3
作者：
L. Excoffier;P. Smouse;J. Quattro
通讯作者：
L. Excoffier;P. Smouse;J. Quattro