title: Genetic diversity and population structure of Chinese White poplar (Populus tomentosa) revealed by SSR markers.
abstract: 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.
authors.affiliation: National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, Peoples' Republic of China.
authors.forename: Qingzhang
authors.initials: Q
authors.lastname: Du
authors.forename: Bowen
authors.initials: B
authors.lastname: Wang
authors.forename: Zunzheng
authors.initials: Z
authors.lastname: Wei
authors.forename: Deqiang
authors.initials: D
authors.lastname: Zhang
authors.forename: Bailian
authors.initials: B
authors.lastname: Li
mesh_terms: D002681:China; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats; D008957:Models, Genetic; D032107:Populus / Q000235:genetics*
chemical_list: D005819:Genetic Markers