State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
Key Laboratory of Tree Breeding and Cultivation, State Forestry and Grassland Administration, Beijing 100091, China.
Int J Mol Sci. 2024 Oct 26;25(21):11515. doi: 10.3390/ijms252111515.
is one of the primary tree species for bioenergy production in temperate regions. In arid/semi-arid northern China, the scarcity of water and nitrogen significantly limits the productivity of poplar plantations. The identification of relevant molecular markers can promote the breeding of resource-efficient varieties. In this study, 188 genotypes of from six provenances served as experimental material. Genetic differentiation analysis, analysis of molecular variance (AMOVA), principal coordinate analysis (PCoA), unweighted pair group method with arithmetic mean (UPGMA) clustering, and genetic structure analysis were performed using selected simple sequence repeat (SSR) markers. Based on these analyses, the association analysis of water-use efficiency (WUE) and nitrogen-use efficiency (NUE) were conducted using general linear model (GLM) and mixed linear model (MLM) approaches. The results showed that 15 pairs of SSR primers successfully amplified across all 188 individuals, with an average of 7.33 alleles (Na) observed per primer pair. The polymorphism information content (PIC) ranged from 0.060 to 0.897, with an average of 0.544, indicating high genetic diversity in the selected markers. The average inbreeding coefficient intra-population (Fis), inbreeding coefficient inter-population (Fit), and inter-population genetic fraction coefficient (Fst) values were 0.005, 0.135, and 0.132, respectively, indicating high heterozygosity, substantial inbreeding within populations, and moderate genetic differentiation, with an average gene flow (Nm) of 1.964, suggesting substantial gene flow between populations. Additionally, molecular variance was primarily within individuals (84.12%). Genetic structure analysis revealed four subgroups, with some degree of genetic admixture among the provenances. In the GLM model, 11 markers were significantly associated with five traits ( < 0.05), with an average contribution rate of 15.82%. Notably, SSR132 and SSR143 were significantly associated with multiple traits ( < 0.05). The MLM model identified two markers (SSR47 and SSR85) significantly associated with ground diameter ( < 0.05) and one marker (SSR80) significantly associated with NUE ( < 0.05). This study identifies loci associated with WUE and NUE, laying a foundation for future genetic improvement and marker-assisted breeding strategies in poplar.
是温带地区生物能源生产的主要树种之一。在中国北方干旱/半干旱地区，水和氮的缺乏极大地限制了杨树人工林的生产力。相关分子标记的鉴定可以促进资源高效品种的培育。本研究以来自六个种源的 188 个基因型为实验材料。采用选择的简单序列重复（SSR）标记进行遗传分化分析、分子方差分析（AMOVA）、主坐标分析（PCoA）、非加权对组平均法（UPGMA）聚类和遗传结构分析。在此基础上，采用一般线性模型（GLM）和混合线性模型（MLM）方法进行水分利用效率（WUE）和氮利用效率（NUE）的关联分析。结果表明，15 对 SSR 引物成功扩增了所有 188 个个体，每个引物对平均观察到 7.33 个等位基因（Na）。多态信息含量（PIC）范围为 0.060-0.897，平均值为 0.544，表明所选标记具有较高的遗传多样性。种群内平均近交系数（Fis）、种群间近交系数（Fit）和种群间遗传分系数（Fst）分别为 0.005、0.135 和 0.132，表明种群内高度杂合，种群内存在大量近交，遗传分化适中，平均基因流（Nm）为 1.964，表明种群间存在大量基因流。此外，分子方差主要在个体内（84.12%）。遗传结构分析表明存在四个亚群，种源之间存在一定程度的遗传混合。在 GLM 模型中，有 11 个标记与五个性状显著相关（ < 0.05），平均贡献率为 15.82%。值得注意的是，SSR132 和 SSR143 与多个性状显著相关（ < 0.05）。MLM 模型鉴定出两个标记（SSR47 和 SSR85）与地径显著相关（ < 0.05），一个标记（SSR80）与 NUE 显著相关（ < 0.05）。本研究鉴定出与 WUE 和 NUE 相关的位点，为杨树未来的遗传改良和标记辅助育种策略奠定了基础。
