Genomic signatures of local adaptation to precipitation and solar radiation in kiwifruit.

Abstract

Local adaptation is critical for plant survivals and reproductions in the context of global environmental change. Heterogeneous environments impose various selection pressures that influence the fitness of organisms and leave genomic signatures during the process of adaptation to local environments. However, unveiling the genomic signatures of adaptation still poses a major challenge especially for perennials due to limited genomic resources. Here, we utilized Actinidia eriantha, a Chinese endemic liana, as a model case to detect drivers of local adaptation and adaptive signals through landscape genomics for 311 individuals collected from 25 populations. Our results demonstrated precipitation and solar radiation were two crucial factors influencing the patterns of genetic variations and driving adaptive processes. We further uncovered a set of genes involved in adaptation to heterogeneous environments. Among them, AeERF110 showed high genetic differentiation between populations and was confirmed to be involved in local adaptation via changes in allele frequency along with precipitation (Prec_03) and solar radiation (Srad_03) in native habitats separately, implying that adaptive loci frequently exhibited environmental and geographic signals. In addition, we assessed genetic offsets of populations under four future climate models and revealed that populations from middle and east clusters faced higher risks in adapting to future environments, which should address more attentions. Taken together, our study opens new perspectives for understanding the genetic underpinnings of local adaptation in plants to environmental changes in a more comprehensive fashion and offered the guides on applications in conservation efforts.