Rubin Matthew J, Schmid Kelly M, Friedman Jannice
Department of Biology Syracuse University Syracuse New York.
Ecol Evol. 2018 Dec 10;9(1):471-481. doi: 10.1002/ece3.4765. eCollection 2019 Jan.
Reproductive timing is a key life-history trait that impacts the pool of available mates, the environment experienced during flowering, and the expression of other traits through genetic covariation. Selection on phenology, and its consequences on other life-history traits, has considerable implications in the context of ongoing climate change and shifting growing seasons. To test this, we grew field-collected seed from the wildflower in a greenhouse to assess the standing genetic variation for flowering time and covariation with other traits. We then created full-sib families through phenological assortative mating and grew offspring in three photoperiod treatments representing seasonal variation in daylength. We find substantial quantitative genetic variation for the onset of flowering time, which covaried with vegetative traits. The assortatively-mated offspring varied in their critical photoperiod by over two hours, so that families differed in their probability of flowering across treatments Allocation to flowering and vegetative growth changed across the daylength treatments, with consistent direction and magnitude of covariation among flowering time and other traits. Our results suggest that future studies of flowering time evolution should consider the joint evolution of correlated traits and shifting seasonal selection to understand how environmental variation influences life histories.
繁殖时间是一个关键的生活史特征，它影响可获得配偶的群体、开花期间所经历的环境以及通过基因协变对其他特征的表达。对物候的选择及其对其他生活史特征的影响，在当前气候变化和生长季节变化的背景下具有重要意义。为了验证这一点，我们在温室中种植从野花采集的野外种子，以评估开花时间的现有遗传变异以及与其他特征的协变。然后，我们通过物候性选型交配创建了全同胞家系，并在代表日照长度季节性变化的三种光周期处理中培育后代。我们发现开花时间开始存在大量数量遗传变异，其与营养性状协变。选型交配的后代临界光周期差异超过两小时，因此不同家系在不同处理下开花的概率也不同。在不同日照长度处理下，开花和营养生长的分配发生变化，开花时间与其他特征之间协变的方向和幅度一致。我们的结果表明，未来关于开花时间进化的研究应考虑相关性状的联合进化和季节性选择的变化，以了解环境变异如何影响生活史。
