Can plants evolve tolerance mechanisms to heterospecific pollen effects? An experimental test of the adaptive potential in Clarkia species
Can plants evolve tolerance mechanisms to heterospecific pollen effects? An experimental test of the adaptive potential in Clarkia species
复制标题
DOI：
10.1111/oik.02594
复制
发表时间：
2016-05-01
期刊：
影响因子：
3.4
通讯作者：
Geber, Monica A.
中科院分区：
文献类型：
--
作者：
Arceo-Gomez, Gerardo;Raguso, Robert A.;Geber, Monica A.
开花植物不会单独出现，通常生长在混合物种群落中，其中传粉媒介共享程度很高，并且在授粉前和授粉后阶段可能会发生通过传粉媒介的相互作用。虽然授粉前相互作用的原因和后果已得到充分研究，但人们对通过异种花粉（HP）接收而发生的授粉后相互作用知之甚少，甚至对这些相互作用的进化影响知之甚少。特别是，植物对HP负面影响的耐受机制的进化程度很少受到关注。在这里，我们的目标是通过实验测试两个共同开花的 Clarkia 物种是否能够进化出 HP 耐受性，以及是否发生对特定 HP 基因型的耐受性（对 HP 的精细局部适应），来填补我们对授粉后相互作用理解的这一空白。我们发现 Clarkia 物种对 HP 效应的耐受性各不相同。此外，在 C. xantiana 中，同种花粉性能和 HP 影响的程度与接受者接触 HP 的历史相关，但在 C. spiosa 中则不然。具体而言，与没有接触过 HP 的群体相比，在之前接触过 HP 的 C. xantiana 植物群体中观察到更好的同种花粉性能和更小的 HP 影响。这些结果表明，植物可能具有进化出对 HP 效应的耐受机制的潜力，但这些可能不是从雌性（柱头、花柱）角度发生，而是从雄性（花粉）角度发生，这种可能性经常被忽视。我们没有发现任何证据表明惠普收据可以进行精细的本地调整。评估植物对 HP 接收负面影响的适应潜力的研究是了解植物与植物授粉后相互作用的进化后果的重要第一步。这些知识对于破译植物与传粉者相互作用在驱动花卉进化和共花群落组成中的作用至关重要。
Flowering plants do not occur alone and often grow in mixed-species communities where pollinator sharing is high and interactions via pollinators can occur at pre- and post-pollination stages. While the causes and consequences of pre-pollination interactions have been well studied little is known about post-pollination interactions via heterospecific pollen (HP) receipt, and even less about the evolutionary implications of these interactions. In particular, the degree to which plants can evolve tolerance mechanisms to the negative effects of HP receipt has received little attention. Here, we aim to fill this gap in our understanding of post-pollination interactions by experimentally testing whether two co-flowering Clarkia species can evolve HP tolerance, and whether tolerance to specific HP genotypes' (fine-scale local adaptation to HP) occurs. We find that Clarkia species vary in their tolerance to HP effects. Furthermore, conspecific pollen performance and the magnitude of HP effects were related to the recipient's history of exposure to HP in C. xantiana but not in C. speciosa. Specifically, better conspecific pollen performance and smaller HP effects were observed in populations of C. xantiana plants with previous exposure to HP compared to populations without such exposure. These results suggest that plants may have the potential to evolve tolerance mechanisms to HP effects but that these may occur not from the female (stigma, style) but from the male (pollen) perspective, a possibility that is often overlooked. We find no evidence for fine-scale local adaptation to HP receipt. Studies that evaluate the adaptive potential of plants to the negative effects of HP receipt are an important first step in understanding the evolutionary consequences of plant-plant post-pollination interactions. Such knowledge is in turn crucial for deciphering the role of plant-pollinator interactions in driving floral evolution and the composition of co-flowering communities.