Clinal variation in seed traits influencing life cycle timing in Arabidopsis thaliana.

Early life history transitions are crucial determining lifetime survival and fecundity. Adaptive evolution in early life history traits involves a complex interplay between the developing plant and its current and future environments. We examined the plant’s earliest life history traits, dissecting an integrated suite of pre-germination processes: primary dormancy, thermal induction of secondary dormancy, and seasonal germination response. We examined genetic variation in the three processes, genetic correlations among the processes, and the scaling of germination phenology with the source populations’ climates. A spring annual life-history was associated with genetic propensities toward both strong primary dormancy and heat-induced secondary dormancy, alone or in combination. Lineages with similar winter and spring annual life-history have both weak primary dormancy and weak thermal dormancy induction. A genetic bias to adopt a spring annual strategy mediated by rapid loss of primary d...早期生活史转换是决定终生存活与繁殖力的关键因素。早期生活史性状的适应性进化涉及发育中的植物与当前及未来环境之间的复杂互作。本研究针对植物的早期生活史核心性状展开分析，剖析了一套完整的萌发前过程：初生休眠（primary dormancy）、次生休眠的热诱导（thermal induction of secondary dormancy）以及季节性萌发响应。我们对这三类过程的遗传变异、过程间的遗传相关，以及萌发物候随源种群气候环境的尺度关联进行了探究。春季一年生生活史型与较强初生休眠、热诱导次生休眠（单独存在或共同存在）的遗传倾向性相关联。具备相似冬、春季一年生生活史型的类群，同时表现出较弱的初生休眠与较弱的热休眠诱导能力。以春季一年生生活史策略的遗传偏向，由初生休眠的快速丧失所介导……