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Genome-wide scans reveal cryptic population structure in a dry-adapted eucalypt

Citation

Steane, DA and Potts, BM and McLean, E and Collins, L and Prober, SM and Stock, WD and Vaillancourt, RE and Byrne, M, Genome-wide scans reveal cryptic population structure in a dry-adapted eucalypt, Tree Genetics and Genomes, 11, (33) pp. 1-14. ISSN 1614-2942 (2015) [Refereed Article]

Copyright Statement

Copyright 2015 Springer-Verlag Berlin Heidelberg

DOI: doi:10.1007/s11295-015-0864-z

Abstract

Genome-wide DArTseq scans of 268 individuals of Eucalyptus salubris, distributed along an aridity gradient in southwestern Australia, revealed cryptic population structure that appears to signal hitherto unappreciated ecotypic differentiation and barriers to gene flow. Genome-wide scans were undertaken on 30 wild-sampled individuals from each of nine populations; 10 individuals per population were measured for habit and functional traits. DArTseq generated 16,122 high-quality markers, of which 56.3 % located to E. grandis chromosomes. Genetic affinities of the nine populations were only weakly correlated with geographic distances. Rather, populations appeared to form two distinct molecular lineages that maintained their distinctiveness in an area of geographic overlap. Twenty-four outlier markers signalled divergent selection and differentiation of the two putative lineages. Populations from the two lineages were phenotypically differentiated in leaf thickness, specific leaf area (SLA) and leaf nitrogen per unit mass (Nmass). The more northerly lineage (with thinner leaves) occurred in hotter, drier conditions with higher radiation. Populations of the more southerly lineage occurred on soils that were relatively low in phosphorus; the trees had thicker leaves, lower SLA and lower leaf Nmass, consistent with general responses to low nutrient levels. While historic isolation and drift may have contributed to the cryptic population structure observed, there is evidence of ecotypic adaptation, which may provide an exogenous barrier to gene flow. This study highlights the power of new molecular technologies to provide novel insights into the genetic architecture of wild populations.

Item Details

Item Type:Refereed Article
Keywords:eucalypt, restoration, speciation
Research Division:Biological Sciences
Research Group:Genetics
Research Field:Population, Ecological and Evolutionary Genetics
Objective Division:Plant Production and Plant Primary Products
Objective Group:Forestry
Objective Field:Forestry not elsewhere classified
Author:Steane, DA (Dr Dorothy Steane)
Author:Potts, BM (Professor Brad Potts)
Author:Vaillancourt, RE (Professor Rene Vaillancourt)
ID Code:103877
Year Published:2015
Web of Science® Times Cited:6
Deposited By:Plant Science
Deposited On:2015-10-28
Last Modified:2017-11-03
Downloads:0

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