Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, 100091, China.
Heilongjiang Forestry Research Institute, Harbin, 150080, China.
BMC Plant Biol. 2024 May 30;24(1):479. doi: 10.1186/s12870-024-05166-6.
The taxonomic classification of Picea meyeri and P. mongolica has long been controversial. To investigate the genetic relatedness, evolutionary history, and population history dynamics of these species, genotyping-by-sequencing (GBS) technology was utilized to acquire whole-genome single nucleotide polymorphism (SNP) markers, which were subsequently used to assess population structure, population dynamics, and adaptive differentiation. Phylogenetic and population structural analyses at the genomic level indicated that although the ancestor of P. mongolica was a hybrid of P. meyeri and P. koraiensis, P. mongolica is an independent Picea species. Additionally, P. mongolica is more closely related to P. meyeri than to P. koraiensis, which is consistent with its geographic distribution. There were up to eight instances of interspecific and intraspecific gene flow between P. meyeri and P. mongolica. The P. meyeri and P. mongolica effective population sizes generally decreased, and Maxent modeling revealed that from the Last Glacial Maximum (LGM) to the present, their habitat areas decreased initially and then increased. However, under future climate scenarios, the habitat areas of both species were projected to decrease, especially under high-emission scenarios, which would place P. mongolica at risk of extinction and in urgent need of protection. Local adaptation has promoted differentiation between P. meyeri and P. mongolica. Genotype‒environment association analysis revealed 96,543 SNPs associated with environmental factors, mainly related to plant adaptations to moisture and temperature. Selective sweeps revealed that the selected genes among P. meyeri, P. mongolica and P. koraiensis are primarily associated in vascular plants with flowering, fruit development, and stress resistance. This research enhances our understanding of Picea species classification and provides a basis for future genetic improvement and species conservation efforts.
白皮松和樟子松的分类一直存在争议。为了研究这两个物种的遗传关系、进化历史和种群历史动态，本研究利用基因分型测序（GBS）技术获取全基因组单核苷酸多态性（SNP）标记，用于评估种群结构、种群动态和适应性分化。基于基因组水平的系统发育和种群结构分析表明，尽管樟子松的祖先是白皮松和红松的杂种，但它是一个独立的松属物种。此外，樟子松与白皮松的亲缘关系比与红松更为密切，这与它的地理分布一致。在白皮松和樟子松之间存在多达 8 次种间和种内基因流。白皮松和樟子松的有效种群大小普遍减少，Maxent 模型表明，从末次冰期最大值（LGM）到现在，它们的栖息地面积先减少后增加。然而，根据未来气候情景预测，两个物种的栖息地面积都将减少，特别是在高排放情景下，这将使樟子松面临灭绝的风险，急需保护。局部适应促进了白皮松和樟子松的分化。基因型-环境关联分析揭示了 96543 个与环境因素相关的 SNP，主要与植物对水分和温度的适应有关。选择扫描揭示了白皮松、樟子松和红松中被选择的基因主要与开花植物、果实发育和抗逆性有关。本研究增进了我们对松属物种分类的认识，为未来的遗传改良和物种保护工作提供了基础。
