Isabel, N, Beaulieu, J, Bousquet, J. Complete congruence between gene diversity estimates derived from genotypic data at enzyme and random amplified polymorphic DNA loci in black spruce. Proc Nat Acad Sci USA, 92: 6369-6373

Centre de Recherche en Biologie Forestière, Faculté de Foresterie at de Géomatique, Université Laval, Sainte-Foy, Canada.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 08/1995; 92(14):6369-73. DOI: 10.1073/pnas.92.14.6369
Source: PubMed


Controversy still exists over the adaptive nature of variation of enzyme loci. In conifers, random amplified polymorphic DNAs (RAPDs) represent a class of marker loci that is unlikely to fall within or be strongly linked to coding DNA. We have compared the genetic diversity in natural populations of black spruce [Picea mariana (Mill.) B.S.P.] using genotypic data at allozyme loci and RAPD loci as well as phenotypic data from inferred RAPD fingerprints. The genotypic data for both allozymes and RAPDs were obtained from at least six haploid megagametophytes for each of 75 sexually mature individuals distributed in five populations. Heterozygosities and population fixation indices were in complete agreement between allozyme loci and RAPD loci. In black spruce, it is more likely that the similar levels of variation detected at both enzyme and RAPD loci are due to such evolutionary forces as migration and the mating system, rather than to balancing selection and overdominance. Furthermore, we show that biased estimates of expected heterozygosity and among-population differentiation are obtained when using allele frequencies derived from dominant RAPD phenotypes.

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    • "dscape levels . Boreal forest tree species , with their widespread populations , high fecundity , and high levels of genetic diversity ( Hamrick et al . 1992 ) , are expected to have a relatively high adap - tive capacity in the face of climate change ( Aitken et al . 2008 ) . Black spruce , for instance , shows a high level of genetic diversity ( Isabel et al . 1995 ; Perry and Bousquet 2001 ) similar to that of many other major boreal forest species . Clinal variation ( adaptive vari - ation ) exists for a number of boreal tree species , suggesting a local adaptation potential , but it is rather limited ( e . g . , Li et al . 1997a , 1997b ) owing to the relatively little time during the Holocene "
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    • "When population genetic structure is significant and high, it is usually taken into account when performing association genetic tests [17,18]. The population genetic structure of P. mariana in the sampled region has been previously investigated using a number of approaches and genetic markers (RAPDs, ESTPs, gene SNPs, cpSSRs), repeatedly resulting in average FST values that were close to zero, large gene flow estimates, and no discernible genetic structure [12,26,34-36,85]. The populations that were sampled also belong to the same historical lineage [12,43]. "
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