PDF(Pubmed)
Abstract：
Understanding the genetic basis of local adaption is crucial in the context of global climate change. Mangroves, as salt-tolerant trees and shrubs in the intertidal zone of tropical and subtropical coastlines, are particularly vulnerable to climate change. Kandelia obovata, the most cold-tolerant mangrove species, has undergone ecological speciation from its cold-intolerant counterpart, Kandelia candel, with geographic separation by the South China Sea. In this study, we conducted whole-genome re-sequencing of K. obovata populations along China\'s southeast coast, to elucidate the genetic basis responsible for mangrove local adaptation to climate. Our analysis revealed a strong population structure among the three K. obovata populations, with complex demographic histories involving population expansion, bottleneck, and gene flow. Genome-wide scans unveiled pronounced patterns of selective sweeps in highly differentiated regions among pairwise populations, with stronger signatures observed in the northern populations compared to the southern population. Additionally, significant genotype-environment associations for temperature-related variables were identified, while no associations were detected for precipitation. A set of 39 high-confidence candidate genes underlying local adaptation of K. obovata were identified, which are distinct from genes under selection detected by comparison between K. obovata and its cold-intolerant relative K. candel. These results significantly contribute to our understanding of the genetic underpinnings of local adaptation in K. obovata and provide valuable insights into the evolutionary processes shaping the genetic diversity of mangrove populations in response to climate change.
摘要：
在全球气候变化的背景下，了解当地适应的遗传基础至关重要。红树林,作为热带和亚热带海岸线潮间带的耐盐树木和灌木，特别容易受到气候变化的影响。Kandeliaobovata,最耐寒的红树林，经历了不耐寒的生态物种形成，KandeliaCandel,与南中国海地理隔离。在这项研究中,我们对中国东南沿海的双叶夜蛾种群进行了全基因组重测序，阐明红树林局部适应气候的遗传基础。我们的分析揭示了三个双歧杆菌种群中强大的种群结构，复杂的人口历史涉及人口扩张，瓶颈,和基因流动。全基因组扫描揭示了成对种群中高度分化区域的选择性扫描的明显模式，与南部人口相比，北部人口的特征更强。此外,确定了温度相关变量的显著基因型-环境关联，而没有检测到降水的关联。确定了一组39个高置信度的候选基因，这些基因是双叶双歧杆菌局部适应的基础。与通过比较K.obovata及其不耐受寒冷的亲戚K.candel检测到的选择基因不同。这些结果极大地有助于我们了解K.obovata局部适应的遗传基础，并为塑造红树林种群遗传多样性以应对气候变化的进化过程提供了有价值的见解。
