Nucleotide diversity among natural populations of a North American poplar (Populus balsamifera, Salicaceae).
Poplars (Populus spp.) comprise an important component of circumpolar boreal forest ecosystems and are the model species for tree genomics. In this study, we surveyed genetic variation and population differentiation in three nuclear genes among populations of balsam poplar (Populus balsamifera) in North America. We examined nucleotide sequence variation in alcohol dehydrogenase 1 (Adh1) and glyceraldehyde 3-phosphate dehydrogenase (G3pdh), two well-studied nuclear loci in plants, and abscisic acid insensitivity 1B (ABI1B), a locus coincident with timing of seasonal dormancy in quantitative trait locus (QTL) studies of hybrid poplars. We compared estimates of baseline population genetic parameters for these loci with those obtained in studies of other poplar species, particularly European aspen (Populus tremula). Average pairwise nucleotide diversity (pi(tot) = 0.00216-0.00353) was equivalent to that in Populus trichocarpa, but markedly less than that in P. tremula. Elevated levels of population structure were observed in ABI1B between the northern and southern regions (F(CT) = 0.184, P < 0.001) and among populations (F(ST) = 0.256, P < 0.001). These results suggest that geographic or taxonomic factors are important for understanding patterns of variation throughout the genus Populus. Our findings have the potential to aid in the design of sampling regimes for conservation and breeding stock and contribute to historical inferences regarding the factors that shaped the genetic diversity of boreal plant species.
Breen
Amy L
AL
Institute of Arctic Biology, and Department of Biology and Wildlife, University of Alaska, 311 Irving 1, 902 N. Koyukuk Dr., Fairbanks, AK 99775, USA.
Glenn
Elise
E
Institute of Arctic Biology, and Department of Biology and Wildlife, University of Alaska, 311 Irving 1, 902 N. Koyukuk Dr., Fairbanks, AK 99775, USA.
Yeager
Adam
A
Institute of Arctic Biology, and Department of Biology and Wildlife, University of Alaska, 311 Irving 1, 902 N. Koyukuk Dr., Fairbanks, AK 99775, USA.
Olson
Matthew S
MS
Institute of Arctic Biology, and Department of Biology and Wildlife, University of Alaska, 311 Irving 1, 902 N. Koyukuk Dr., Fairbanks, AK 99775, USA.
D000426:Alcohol Dehydrogenase / Q000235:genetics; D001483:Base Sequence; D014644:Genetic Variation; D005843:Geography; D005986:Glyceraldehyde 3-Phosphate / Q000235:genetics; D006239:Haplotypes; D009656:North America; D011157:Population Dynamics; D032107:Populus / Q000201:enzymology / Q000235:genetics; D018401:Sample Size
D005986:Glyceraldehyde 3-Phosphate; D000426:Alcohol Dehydrogenase