Using Landscape Genomics to Assess Local Adaptation of Fruit Trees to Current and Future Climatic Conditions

Local adaptation has been proven to be common in plants and extensively studied, from increasing plant yields to predicting species responses to the future changing climate. Compared to main crops and forest trees, however, investigations into the local adaptation of fruit trees across current and future climatic landscapes are still lacking. With the explosion of large-scale genomic data, landscape genomics has emerged as a new approach to identify candidate loci that are related to environmental variations (i.e., genotype-environment associations or GEA), while allowing for downstream analyses such as the calculation of adaptive indices and genetic offsets, which can be used to predict spatial-temporal shifts of populations in response to future environmental change. Here, by summarizing the cutting-edge methods for investigating species' local adaptation as well as evaluating the genetic offsets based on the current genotype-environment association, we call for more efforts on elucidating genomic and molecular underpinnings of local adaptation of fruit trees and forecasting the possible maladaptation under rapid climate change. In summary, the study of local adaptation in fruit trees is important for ensuring long-term sustainability and productivity. The emergence of landscape genomics has great potential to advance our understanding of the genomic and molecular mechanisms underlying local adaptation and to predict responses to environmental change.