Ricote Natalia, Bastias Cristina C, Valladares Fernando, Pérez Fernanda, Bozinovic Francisco
Departmento Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
Center of Applied Ecology & Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile.
Front Plant Sci. 2019 Dec 17;10:1595. doi: 10.3389/fpls.2019.01595. eCollection 2019.
Angiosperms are highly diverse in their reproductive systems, including predominantly selfing, exclusive outcrossing, and mixed mating systems. Even though selfing can have negative consequences on natural populations, it has been proposed that plants having a predominantly selfing strategy are also associated with fast development strategies through time limitation mechanisms that allow them to complete their life cycle before the onset of severe drought. This relationship might be affected by the challenges imposed by global change, such as a decrease in pollinator availability and the earlier and more severe onset of droughts. In this work, our aim was to investigate whether selfing is correlated with a dehydration avoidance strategy, and how this could affect drought resistance and survival in two species with different types of selfing: pollinator-independent delayed selfing () and pollinator-dependent selfing (), representing a gradient in selfing rates. We hypothesize that delayed selfing species and highly selfing populations will show "fast" plant traits whereas we will find no pattern in more outcrossed populations of the pollinator-dependent species. However, we predicted that high selfing populations would have lower survival rates when exposed to chronic drought early in their development since fast traits imply physiological compromises that will affect their drought survival. To evaluate these hypotheses, we characterized different physiological and morphological traits in response to two contrasting treatments (moist and dry) in a total of six populations of the two species. We found a relationship between the delayed selfing species and a dehydration avoidance strategy and also with low drought survival. Our work offers evidence to support the importance of abiotic factors, such as drought, on the possible variation in selfing rates on natural populations, and the effect that this mating system could have in their ability to face new environmental conditions such as those imposed by climate change.
被子植物的繁殖系统高度多样，主要包括自花授粉、专性异花授粉和混合交配系统。尽管自花授粉可能对自然种群产生负面影响，但有人提出，具有主要自花授粉策略的植物也与快速发育策略相关，这是通过时间限制机制实现的，该机制使它们能够在严重干旱开始之前完成生命周期。这种关系可能会受到全球变化带来的挑战的影响，例如传粉者数量减少以及干旱提前且更严重地发生。在这项研究中，我们的目的是调查自花授粉是否与脱水避免策略相关，以及这如何影响两种具有不同自花授粉类型的物种的抗旱性和存活率：不依赖传粉者的延迟自花授粉（）和依赖传粉者的自花授粉（），它们代表了自花授粉率的一个梯度。我们假设延迟自花授粉物种和高度自花授粉种群将表现出“快速”的植物特征，而在依赖传粉者物种的更多异花授粉种群中我们将找不到模式。然而，我们预测，高度自花授粉种群在发育早期暴露于长期干旱时存活率会较低，因为快速生长的特征意味着生理上的妥协，这将影响它们在干旱中的存活。为了评估这些假设，我们在两种物种的总共六个种群中，针对两种对比处理（湿润和干燥），对不同的生理和形态特征进行了表征。我们发现延迟自花授粉物种与脱水避免策略以及低干旱存活率之间存在关联。我们的研究为支持非生物因素（如干旱）对自然种群自花授粉率可能变化的重要性，以及这种交配系统对它们面对新环境条件（如气候变化所带来的条件）的能力的影响提供了证据。
