Marine heat waves are increasing in magnitude, duration, and frequency as a result of climate change and are the principal global driver of mortality in reef‐building corals. Resilience‐based genetic management may increase coral heat tolerance, but it is unclear how temperature responses are regulated at the genome level and thus how corals may adapt to warming naturally or through selective breeding. Here we combine phenotypic, pedigree, and genomic marker data from colonies sourced from a warm reef on the Great Barrier Reef reproductively crossed with conspecific colonies from a cooler reef to produce combinations of warm purebreds and warm‐cool hybrid larvae and juveniles. Interpopulation breeding created significantly greater genetic diversity across the coral genome compared to breeding between populations and maintained diversity in key regions associated with heat tolerance and fitness. High‐density genome‐wide scans of single nucleotide polymorphisms (SNPs) identified alleles significantly associated with larval families reared at 27.5°C (87–2,224 loci), including loci putatively associated with proteins involved in responses to heat stress (cell membrane formation, metabolism, and immune responses). Underlying genetics of these families explained 43% of PCoA multilocus variation in survival, growth, and bleaching responses at 27.5°C and 31°C at the juvenile stage. Genetic marker contribution to total variation in fitness traits (narrow‐sense heritability) was high for survival but not for growth and bleaching in juveniles, with heritability of these traits being higher at 31°C relative to 27.5°C. While based on only a limited number of crosses, the mechanistic understanding presented here demonstrates that allele frequencies are affected by one generation of selective breeding, key information for the assessments of genetic intervention feasibility and modelling of reef futures.

中文翻译：

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全基因组SNP分析表明，通过珊瑚的选择性繁殖，适应性遗传变异有所增加。

由于气候变化，海洋热浪的数量，持续时间和频率都在增加，并且是造成珊瑚礁珊瑚死亡的主要全球因素。基于复原力的基因管理可能会提高珊瑚的耐热性，但是目前尚不清楚如何在基因组水平上调节温度响应，从而不清楚珊瑚如何适应自然变暖或通过选择性繁殖。在这里，我们将来自大堡礁上一个温暖礁石的菌落的表型，系谱和基因组标记数据与一个较冷的礁石上的同种菌落繁殖繁殖后杂交，以产生温暖的纯种，温暖凉爽的杂交幼体和幼虫的组合。与种群之间的繁殖相比，种群间繁殖在整个珊瑚基因组上创造了更大的遗传多样性，并且在与耐热性和适应性相关的关键区域保持了多样性。单核苷酸多态性（SNP）的高密度全基因组扫描确定了与在27.5°C饲养的幼体家族显着相关的等位基因（87–2,224个基因座），包括可能与参与热应激反应的蛋白质（细胞膜形成，代谢和免疫反应）。这些家族的基础遗传学解释了PCoA多基因座在少年阶段在27.5°C和31°C的存活，生长和漂白反应中有43％的变异。遗传标记对适应性状总变异（狭义遗传力）的贡献对于存活率很高，但对未成年人的生长和褪色则不高，相对于27.5°C，这些性状的遗传力在31°C时较高。虽然仅基于有限的杂交，但此处给出的机理理解证明等位基因频率受一代选择性育种，评估遗传干预可行性和礁石期货建模的关键信息的影响。