Genomic responses to climate: Understanding local adaptation in the Andean tree species Nothofagus pumilio and implications for a changing world
Loading...
Date
Publisher
Philipps-Universität Marburg
Abstract
Nothofagus pumilio is a foundation tree species that inhabits a 2000-km-long range in
the southern Andes, a region with two perpendicular environmental gradients:
temperature and photoperiod (North–South), and precipitation (West–East). We
investigated local adaptation patterns by searching for relationships between
environmental clines and signatures of adaptation in candidate genes related to
stress response, growth, and phenology. Using a paired site sampling design within a
landscape genome analysis, we analyzed 493 adult N. pumilio trees in 20 sampling
sites across the species' latitudinal range. We screened 47,336 single nucleotide poly-
morphism (SNP) loci in 1632 contigs (i.e., coding regions along the genome). Popula-
tion structure and genetic diversity analyses preceded four genome scan analyses
using genetic and environmental data. Population structure and genetic diversity are
mainly oriented along the latitude axis. Genome scans identified 445 outlier SNPs,
which are loci showing signatures of selection. Temperature and photoperiod
variables were associated with notably more outliers than precipitation. However, the most frequent biological functions among genes were water deprivation response
and cold response, suggesting that stress response is comprised of complex and poly-
genic traits that are affected by many environmental variables. Our findings suggest
that N. pumilio shows signatures of local adaptation to extant climate conditions,
including temperature, photoperiod, and precipitation. However, climate change is
likely to alter existing relationships among environmental conditions to which this
species is currently adapted. These changes may have unpredictable consequences
for the species' future survival, adaptation potential, and the people who depend
upon these forests.
Metadata
License
Except where otherwised noted, this item's license is described as Creative Commons Attribution-NonCommercial 4.0 - CC BY NC