Zhang Yazhou, Liu Yuan, Sun Lu, Baskin Carol C, Baskin Jerry M, Cao Min, Yang Jie
CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
New Phytol. 2022 Jun;234(5):1770-1781. doi: 10.1111/nph.18099. Epub 2022 Apr 7.
Seed dormancy is an important life history state that increases survival and fitness of seed plants, and thus it has attracted much attention. However, global biogeography, effects of paleoenvironment, evolutionary roles of dormancy transitions, and differences in adaptations of seed dormancy between life-forms are poorly understood. We compiled global distribution records for seed dormancy of 12 743 species and their phylogeny to explore the biogeographic patterns, environmental drivers, and evolutionary transitions between seed dormancy and nondormancy. Biogeographic patterns reveal a low proportion of dormancy in tropical rainforest regions and arctic regions and a high proportion of dormancy in remaining tropical, subtropical, and temperate regions for all species and woody species. Herbaceous plants show a greater proportion of dormancy in most global regions except arctic regions. Seasonal environments have a consistent positive influence on the dormancy pattern for both life-forms, but precipitation and temperature were important driving factors for woody and herbaceous plants, respectively. Seed dormancy was the dominating state during the evolutionary history of seed plants, and dormancy transitions had a significant relationship with paleotemperatures. Dormancy and nondormancy transitions in response to fluctuating environments during long-term evolutionary history may have played important roles in the diversification of seed plants. Our results add to the current knowledge about seed dormancy from macro-adaptive perspectives and the potential adaptive mechanisms of seed plants.
种子休眠是一种重要的生活史状态，它提高了种子植物的存活率和适合度，因此备受关注。然而，全球生物地理学、古环境的影响、休眠转变的进化作用以及不同生活型之间种子休眠适应性的差异仍知之甚少。我们汇编了12743个物种种子休眠的全球分布记录及其系统发育关系，以探索种子休眠与非休眠之间的生物地理模式、环境驱动因素和进化转变。生物地理模式显示，对于所有物种和木本物种而言，热带雨林地区和北极地区的休眠比例较低，而其余热带、亚热带和温带地区的休眠比例较高。除北极地区外，草本植物在全球大多数地区的休眠比例更高。季节性环境对两种生活型的休眠模式都有一致的积极影响，但降水和温度分别是木本植物和草本植物的重要驱动因素。种子休眠在种子植物的进化历史中是主导状态，休眠转变与古温度有显著关系。在长期进化历史中，响应环境波动的休眠和非休眠转变可能在种子植物的多样化过程中发挥了重要作用。我们的研究结果从宏观适应角度增加了当前关于种子休眠的知识以及种子植物潜在的适应机制。
