Zhu Xianliang, Zhang Hairun, Lu Zhaohua, Kang Ming, Wang Baosheng, Bush David, Li Changrong, Li Fagen
Key Laboratory of National Forestry and Grassland Administration on Tropical Forestry Research, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, 510520, China.
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
Plant J. 2025 Jul;123(1):e70336. doi: 10.1111/tpj.70336.
Accelerated global climate change and increased species introduction across international scales have raised concerns about the potential for trees to experience maladaptation or lagging adaptation in response to these environmental shifts. However, our knowledge regarding the relationship between the genomic metrics used to predict maladaptation and actual fitness proxies in trees remains limited. Here, we present a population genomic analysis of 295 families from 28 provenances of Eucalyptus pellita, a widely cultivated fast-growing tree species, and conducted two common garden experiments. Genomic susceptibility encompassing individual heterozygosity (H), genomic inbreeding (F), and genomic load (inferred from deleterious mutations) exhibited distinct geographic patterns, shedding light on the origin and evolutionary history of E. pellita. The genetic basis of local adaptation was elucidated through genotype-environment associations and genome-wide association studies, including 198 loci associated with climate and 2388 loci regulating different traits. Furthermore, Australian provenances have higher genomic vulnerability under prospective climate alterations than Papua New Guinea and Indonesia provenances. By integrating phenotypic data across two common gardens, the relationship between leaf functional traits and predicted metrics of maladaptation was closer than growth attributes. Notably, pronounced natural selection signals linked to leaf morphogenesis have been identified by comparing two lineages spanning the oceans. This study underscores the immense potential of leveraging genomic susceptibility and genomic vulnerability to decipher the local (mal)adaptation of forest trees.
全球气候变化加速以及国际范围内物种引入增加，引发了人们对树木在应对这些环境变化时可能出现适应不良或适应滞后的担忧。然而，我们对于用于预测树木适应不良的基因组指标与实际适应度代理指标之间关系的了解仍然有限。在此，我们对来自28个种源的295个家系的粗皮桉进行了群体基因组分析，粗皮桉是一种广泛种植的速生树种，并开展了两项共同园试验。包含个体杂合度（H）、基因组近亲繁殖系数（F）和基因组负荷（从有害突变推断）的基因组易感性呈现出明显的地理模式，揭示了粗皮桉的起源和进化历史。通过基因型 - 环境关联和全基因组关联研究阐明了局部适应的遗传基础，其中包括198个与气候相关的位点和2388个调控不同性状的位点。此外，在未来气候改变下，澳大利亚种源的基因组脆弱性高于巴布亚新几内亚和印度尼西亚种源。通过整合两个共同园的表型数据，叶片功能性状与预测的适应不良指标之间的关系比生长属性更为密切。值得注意的是，通过比较跨越海洋的两个谱系，已识别出与叶片形态发生相关的明显自然选择信号。这项研究强调了利用基因组易感性和基因组脆弱性来解读林木局部（不）适应的巨大潜力。
