National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, Peoples' Republic of China.
J Hered. 2012 Nov-Dec;103(6):853-62. doi: 10.1093/jhered/ess061. Epub 2012 Sep 24.
An understanding of allelic diversity and population structure is important in developing association studies and constructing core collections for tree breeding. We examined population genetic differentiation in the native Populus tomentosa by genotyping 460 unrelated individuals using 20 species-specific microsatellite markers. We identified 99 alleles with a mean of 4.95 observed alleles per locus, indicating a moderate level of polymorphism across all individuals. A model-based population structure analysis divided P. tomentosa into 11 subpopulations (K = 11). The pattern of individual assignments into the subsets (K = 3) provided reasonable evidence for treating climatic zones as genetic regions for population genetics. The highest level of genetic variation was found in the southern region (i.e., N = 93, N (P) = 11, H (E) = 0.445, F = -0.102), followed by the northeastern and northwestern regions. Thus, the southern region is probably the center of the current species distribution. No correlation was found between population genetic distance and geographic distance (r = 0.0855, P = 0.3140), indicating that geographical distance was not the principal factor influencing genetic differentiation in P. tomentosa. These data provide a starting point for conserving valuable natural resources and optimizing breeding programs.
了解等位基因多样性和群体结构对于开展关联研究和构建树木育种核心群体非常重要。我们通过使用 20 个种特异性微卫星标记对 460 个无关个体进行基因分型，研究了本地毛白杨的群体遗传分化。我们在所有个体中发现了 99 个等位基因，每个位点的平均观测等位基因数为 4.95，表明存在中等程度的多态性。基于模型的群体结构分析将毛白杨分为 11 个亚群（K=11）。个体分配到子集（K=3）的模式为将气候带作为遗传区域进行群体遗传学研究提供了合理的证据。遗传变异程度最高的是南部地区（即 N=93，N（P）=11，H（E）=0.445，F=-0.102），其次是东北和西北部地区。因此，南部地区可能是当前物种分布的中心。种群遗传距离与地理距离之间没有相关性（r=0.0855，P=0.3140），表明地理距离不是影响毛白杨遗传分化的主要因素。这些数据为保护有价值的自然资源和优化育种计划提供了起点。
