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Environmental versus geographical determinants of genetic structure in two subalpine conifers
Author(s) -
Mosca Elena,
GonzálezMartínez Santiago C.,
Neale David B.
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12476
Subject(s) - genetic structure , analysis of molecular variance , biology , local adaptation , isolation by distance , ecology , population , adaptation (eye) , mantel test , genetic variation , genetics , demography , neuroscience , sociology , gene
Summary Alpine ecosystems are facing rapid human‐induced environmental changes, and so more knowledge about tree adaptive potential is needed. This study investigated the relative role of isolation by distance ( IBD ) versus isolation by adaptation ( IBA ) in explaining population genetic structure in A bies alba and L arix decidua , based on 231 and 233 single nucleotide polymorphisms ( SNP s) sampled across 36 and 22 natural populations, respectively, in the Alps and Apennines. Genetic structure was investigated for both geographical and environmental groups, using analysis of molecular variance ( AMOVA ). For each species, nine environmental groups were defined using climate variables selected from a multiple factor analysis. Complementary methods were applied to identify outliers based on these groups, and to test for IBD versus IBA . AMOVA showed weak but significant genetic structure for both species, with higher values in L . decidua . Among the potential outliers detected, up to two loci were found for geographical groups and up to seven for environmental groups. A stronger effect of IBD than IBA was found in both species; nevertheless, once spatial effects had been removed, temperature and soil in A . alba , and precipitation in both species, were relevant factors explaining genetic structure. Based on our findings, in the A lpine region, genetic structure seems to be affected by both geographical isolation and environmental gradients, creating opportunities for local adaptation.