Effects of life-history traits and species distribution on genetic structure at maternally inherited markers in European trees and shrubs
Résumé
Aim To examine relationships between life-history traits, ecological and chorological characteristics of woody plant species and patterns of genetic differentiation among populations as assessed by chloroplast DNA (cpDNA) markers, and to compare them with patterns previously described from nuclear markers. Location Europe. Methods Data on cpDNA variation were compiled for 29 temperate European broad-leaved tree and shrub species. Six qualitative and three quantitative characters of the species were tested for their relationship with two parameters of genetic population differentiation (GST and NST). Both direct species comparisons and phylogenetically independent contrast analyses were performed. Results When the phylogeny was not taken into account, five characters were significantly related to levels of population differentiation. The relationship disappeared in all but two cases (distribution type and seed mass) when analyses controlled for phylogenetic relationships among species. Main conclusions The correlation between distribution type (boreal-temperate or temperate) and cpDNA differentiation of temperate European woody plant species suggests that their Quaternary history, in particular the location and isolation of their glacial refugia, is an important determinant of their present-day level of genetic structure. By contrast, the relationship between life-history traits and genetic differentiation at maternally inherited markers is weaker, especially when phylogenetic effects are controlled for