Pollinator preference and pollen viability mediated by flower color synergistically determine seed set in an Alpine annual herb.
Pollinator preference and pollen viability mediated by flower color synergistically determine seed set in an Alpine annual herb.
复制标题
花色介导的传粉者偏好和花粉活力协同决定阿尔卑斯一年生草本植物的结籽
DOI：
10.1002/ece3.2899
复制
发表时间：
2017-05
影响因子：
2.6
通讯作者：
Niklas KJ
中科院分区：
文献类型：
--
作者：
Mu J;Yang Y;Luo Y;Su R;Niklas KJ
龙胆表现出惊人的花色多态，在种群内和单个植物上都有蓝花和白花的个体(由苍蝇和蜜蜂授粉)。以前对该物种的研究表明，传粉者的喜好和花温的变化是整个花季花色的函数。然而，几乎没有研究探索花色对花粉活力的影响(由花药温度调节)和传粉者在整个花季期间对群体或单个植物繁殖成功(结实)的偏好的影响。根据先前的观察，我们假设花色既影响花粉活力(作为花药温度的函数)，也影响花粉沉积(作为传粉者偏好的函数)，从而在花季的高峰期协同决定生殖成功。这一假说在西藏高寒草甸的野外观察和人工授粉实验中得到了验证。广义线性模型和通径分析表明，花粉生活力由花色、花期和花药温度决定。在早花期花药温度与花粉活力呈正相关，而在中晚花期花药温度与花粉活力呈负相关。花粉沉积由花色、花期(早、中、晚)和花粉生活力决定。花粉活力和花粉沉积受到花色的影响，而花色又影响花季(即授粉数量最多的时候)的种子结实。人工授粉试验表明，花粉生活力和花粉沉降量直接影响结实率。这些数据共同表明，授粉者对花色和花粉生活力的偏好在花期发生了变化，从而优化了白花棉的成功繁殖。这项研究是少数同时考虑了花粉活力和花粉沉积对同一种群和单个植物繁殖成功的影响的研究之一。
Gentiana leucomelaena manifests dramatic flower color polymorphism, with both blue‐ and white‐flowered individuals (pollinated by flies and bees) both within a population and on an individual plant. Previous studies of this species have shown that pollinator preference and flower temperature change as a function of flower color throughout the flowering season. However, few if any studies have explored the effects of flower color on both pollen viability (mediated by anther temperature) and pollinator preference on reproductive success (seed set) in a population or on individual plants over the course of the entire flowering season. Based on prior observations, we hypothesized that flower color affects both pollen viability (as a function of anther temperature) and pollen deposition (as a function of pollinator preference) to synergistically determine reproductive success during the peak of the flowering season. This hypothesis was tested by field observations and hand pollination experiments in a Tibetan alpine meadow. Generalized linear model and path analyses showed that pollen viability was determined by flower color, flowering season, and anther temperature. Anther temperature correlated positively with pollen viability during the peak of the early flowering season, but negatively affected pollen viability during the peak of the mid‐ to late flowering season. Pollen deposition was determined by flower color, flowering season (early, or mid‐ to late season), and pollen viability. Pollen viability and pollen deposition were affected by flower color that in turn affected seed set across the peak of the flowering season (i.e., when the greatest number of flowers were being pollinated). Hand pollination experiments showed that pollen viability and pollen deposition directly influenced seed set. These data collectively indicate that the preference of pollinators for flower color and pollen viability changed during the flowering season in a manner that optimizes successful reproduction in G. leucomelaena. This study is one of a few that have simultaneously considered the effects of both pollen viability and pollen deposition on reproductive success in the same population and on individual plants.