Abstract

Saxifraga florulenta is a monocarpic species endemic to SW Alps, whose reproductive biology is still unknown. Its knowledge may provide useful information on how the species may face the global warming. In this study, we investigated the plant-pollinator interactions and the mating system of the plant. We described the phenology of the inflorescences, we evaluated the type of pollinators, we verified self and cross-pollination and lastly we quantified the reproductive success of the plants. In spite of the low visitation rate of pollinators, S. florulenta shows high fruit set and seed set. The plant exhibits a prolonged flowering period and has a definite inflorescence, characterized by a sequential blooming bearing both female- or male-phase flowers at the same time; in addition, flowers show a delayed maturation and movement of stamens. These floral and inflorescence traits lead to a mixed reproduction mode which guarantees reproductive success by adopting the “best of two worlds” strategy. The species maximizes its resource investment by having inflorescence size and number of flowers directly related to plant size, whilst fruit and seed set as well as seeds per flower did not show any statistically significant relationship with plant size.

摘要

虎耳草是西南阿尔卑斯山特有的单果类，其生殖生物学仍是未知的。它的知识可以为该物种如何面对全球变暖提供有用的信息。在这项研究中，我们调查了植物与传粉媒介的相互作用以及植物的交配系统。我们描述了花序的物候，评估了传粉媒介的类型，验证了自花传粉和异花传粉，最后我们定量了植物的繁殖成功。尽管传粉者的访视率较低，但S. florulenta显示出较高的坐果率和结实率。该植物表现出延长的开花期，并具有一定的花序，其特征在于连续开花，同时开花雌性或雄性。此外，花显示出延迟的雄蕊成熟和运动。这些花和花的性状导致了一种混合繁殖方式，通过采用“两全其美”策略来确保繁殖成功。该物种通过将花序大小和花朵数量与植物大小直接相关来最大化其资源投资，而果实和种子结实以及每朵花朵的种子与植物大小没有任何统计学上的显着关系。