Abstract:

Understanding the genetic basis underpinning local adaptation is one of the fundamental issues in ecological and evolutionary biology. In this study, we investigated the genomic basis underlying local adaptation of the Chinese wingnut (Pterocarya stenoptera C. DC). Our population genomic analyses revealed nine spatial genetic clusters across the current distribution range of this species. Based on the assessment of genetic–environment association, we found that adaptive divergence of the P. stenoptera populations were mainly shaped by solar radiation during fruit development, temperature seasonality, annual temperature, precipitation, and air humidity. In particular, our genome-wide scanning identified a total of 801 candidate single nucleotide polymorphisms (SNPs) that are highly correlated with diverse environmental factors. Further functional annotation of the SNPs identified some candidate genes that are involved into temperature, water, and light adaptation. Taken together, our results suggest that natural selection during local adaptation has contributed to the success of survival to diverse heterogenous environmental conditions. Our study provides important insights into the fundamental knowledge of the genetic basis underlying the local adaptation of non-model species.

Key words: environmental association analysis, genomic scans, landscape genomics, local adaptation, Pterocarya stenoptera, SLAF sequencing