Publication Date:
2020-08-25
Description:
Global change-driven droughts are triggering worldwide forest dieback which are predicted to increase even further. Here, we combined genome-wide single nucleotide polymorphisms (SNPs) and dendrochronological approaches to assess genetically-based individual tree vulnerability to past extreme droughts that caused massive mortality of Nothofagus dombeyi forests in northern Patagonia. We collected fresh leaves and wood cores from pairs of Healthy Crown (HC) and Partially Affected crown (PA) trees at four sites impacted by 1998, 2008 and 2014 droughts. We used dendrochronological techniques to estimate parameters in terms of growth trends due to drought and genomic analysis to assess its relationship with water stress. While 5,155 neutral loci did not discriminate PA from HC trees, a set of 33 adaptive SNPs did so, 8 of which were related to hydric stress. Association analysis between genomic variants and dendrophenotypic traits yielded 6 SNPs that were associated with a growth measure as resilience to cope with drought. Our preliminary results indicate that susceptibility to drought in N. dombeyi could be determined at the genomic level. The combination of both approaches provides a framework for the identification and analysis of candidate genes for stress response in non-model species.
Print ISSN:
0045-5067
Electronic ISSN:
1208-6037
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
