中国山杨遗传多样性及遗传结构分析

利用6个单拷贝核基因标记,对中国山杨(Populus davidiana Dode)14个自然居群的遗传多样性和遗传分化水平进行了研究。结果表明,中国山杨表现出较高的遗传多样性水平,各居群间基因流(Nm)为0.66;居群内的变异占总变异的百分比(71.82%)大于居群间(28.18%)。Mantel test检验结果显示居群遗传距离和地理距离间没有相关性。失配分布检测显示中国山杨历史上曾经历过种群的扩张。复杂的种群历史动态、高度异交和较高的碱基突变速率是中国山杨遗传多样性水平较高的原因;而较强的花粉和种子扩散能力及中国山杨的连续分布可能是其居群间遗传分化较小的原因。

Nucleotide polymorphism and genetic structure of Populus davidiana Dode

In this study, six single-copy nuclear gene markers were used to study the nucleotide polymorphisms and genetic structures of 14 natural populations of Populus davidiana Dode. Results showed that P. davidiana harbored high levels of nucleotide polymorphisms. The average gene flow (N_m) among populations was 0.66; the percentage of variation within the population (71.82%) was greater than that among populations (28.18%). The Mantel test illustrated that there was no correlation between geographical and genetic distances. Results of mismatch distribution demonstrated that P. davidiana experienced historical population expansion. The comprehensive population history, high outcrossing, and high rate of base mutations were the main factors contributing to the high level of nucleotide polymorphisms. The high dispersal of pollen and seeds as well as continuous distribution resulted in the relatively low genetic differentiation.