Data from "Strong environmental and genome-wide population differentiation underpins adaptation and high genomic vulnerability in the dominant Australian kelp (<i>Ecklonia radiata</i>)"

<b>Abstract</b>Ongoing and predicted range loss of kelp forests in response to climatic stressors are pressing marine managers to look into the adaptive capacity of populations to inform conservation strategies. Characterising how adaptive genetic diversity and structure relate to present and future environmental variation represents an emerging approach to quantifying kelp vulnerability to environmental change and identifying populations with genotypes that potentially confer an adaptive advantage for copying with future ocean conditions.The dominant Australian kelp, Ecklonia radiata, was genotyped from 10 locations spanning 2,000 km of coastline and a 9.5°C average temperature gradient, along the east coast of Australia, a global warming hotspot. ddRAD sequencing was used to generate 10,700 high quality single nucleotide polymorphisms (SNPs) and characterize levels of neutral and adaptive genomic diversity and structure. The adaptive dataset, reflecting portions of genome putatively under selection, was used to infer genomic vulnerability by 2050 under the RCP 8.5 scenario.There was strong neutral genetic differentiation between Australia mainland and Tasmanian populations, but only weak genetic structure among mainland populations within the main path of the East Australian Current. Genetic diversity was highest in the centre of the range, and lowest in the warm-edge population. The adaptive SNP candidates revealed similar genetic structure patterns with a spread of adaptive alleles across most warm (northern) populations. The lowest, but most unique, adaptive genetic diversity values were found in both warm and cool population edges, suggesting local adaptation but low evolutionary potential. Critically, genomic vulnerability modelling identified high levels of vulnerability to future environmental conditions in Tasmanian populations. Populations of kelp at range edges are unlikely to adapt and keep pace with predicted climate change. Ensuring the persistence of these kelp forests, by boosting resilience to climate change, may require active management strategies with assisted adaptation in warm-edge (northern) populations and assisted gene flow in cool-edge (Tasmania) populations.**摘要**：为应对气候压力引发的海带林持续且可预测的分布萎缩，海洋管理者亟需探究种群的适应能力，以此为保护策略制定提供依据。阐明适应性遗传多样性与群体结构如何响应当前及未来环境变化，是量化海带对环境变化的脆弱性、筛选携带有望适配未来海洋环境的适应性优势基因型种群的新兴研究路径。本研究以澳大利亚东海岸这一全球变暖热点区域的优势海带——辐射海带（Ecklonia radiata）为研究对象，采样覆盖2000公里海岸线及9.5℃的平均温度梯度，涵盖10个采样点位。研究采用ddRAD测序技术，生成了10700个高质量单核苷酸多态性（single nucleotide polymorphisms, SNPs）位点，以此表征中性与适应性基因组多样性及群体结构。以推测受选择作用的基因组区域构建的适应性数据集，被用于推断典型浓度路径8.5（Representative Concentration Pathway 8.5，RCP 8.5）情景下至2050年的基因组脆弱性。研究结果显示，澳大利亚大陆与塔斯马尼亚种群间存在显著的中性遗传分化，但在东澳洋流主路径内的大陆种群间仅存在微弱遗传结构。遗传多样性在分布范围的中心区域最高，而在暖边缘种群中最低。适应性SNP候选位点揭示了相似的遗传结构模式，多数适应性等位基因在暖温带（北部）种群中广泛分布。暖边缘与冷边缘种群均呈现最低但最独特的适应性遗传多样性水平，这暗示其存在局部适应但进化潜力较低。尤为关键的是，基因组脆弱性模型显示塔斯马尼亚种群对未来环境条件具有极高的脆弱性。分布范围边缘的海带种群难以适应气候变化并跟上其速率。为维持这些海带林的存续，需通过提升其气候适应韧性制定主动管理策略：针对暖边缘（北部）种群采用辅助适应手段，针对冷边缘（塔斯马尼亚）种群开展辅助基因流工作。