Polygamy or subdioecy? The impact of diallelic self-incompatibility on the sexual system in Fraxinus excelsior (Oleaceae)
Polygamy or subdioecy? The impact of diallelic self-incompatibility on the sexual system in Fraxinus excelsior (Oleaceae)
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DOI：
10.1098/rspb.2018.0004
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发表时间：
2018-02-28
影响因子：
4.7
通讯作者：
Dufay, Mathilde
中科院分区：
文献类型：
--
作者：
Saumitou-Laprade, Pierre;Vernet, Philippe;Dufay, Mathilde
开花植物如何从雌雄同体反复进化到雌雄分离（雌雄异株）是进化生物学的一个核心问题。在这里，我们研究了双等位自交不亲和（DSI）是否与一夫多妻的白蜡树（蜡树）的性别专一化有关，这最终会促进雌雄异株的进化。通过种间杂交，我们提供了DSI系统与性表型之间密切关系的证据。F. excelsior的生殖系统以前被认为是一夫多妻制（男女两性在不同程度上分配男性和女性的功能），因此实际上表现为次雌雄异株系统。雌雄同体和雌性属于一个SI组，在功能上以雌性繁殖，而雄性和偏向雄性的雌雄同体属于另一个SI组，在功能上是雄性。我们的研究结果为开花植物性别分化的进化提供了另一种机制。
How flowering plants have recurrently evolved from hermaphroditism to separate sexes (dioecy) is a central question in evolutionary biology. Here, we investigate whether diallelic self-incompatibility (DSI) is associated with sexual specialization in the polygamous common ash (Fraxinus excelsior), which would ultimately facilitate the evolution towards dioecy. Using interspecific crosses, we provide evidence of strong relationships between the DSI system and sexual phenotype. The reproductive system in F. excelsior that was previously viewed as polygamy (co-occurrence of unisexuals and hermaphrodites with varying degrees of allocation to the male and female functions) and thus appears to actually behave as a subdioecious system. Hermaphrodites and females belong to one SI group and functionally reproduce as females, whereas males and male-biased hermaphrodites belong to the other SI group and are functionally males. Our results offer an alternative mechanism for the evolution of sexual specialization in flowering plants.