Study on Population Variation and Phylogeography of Cherry in China（Cerasus conradinae）

Abstract

Cerasus conradinae is an important germplasm resource of wild cherry in China. In this work, sampling was expanded and genetic evidence was added for further study. The current and future potential populations were predicted by niche model. Based on three cpDNA sequences and one nrDNA sequence, and combined with the phylogeographic evolution of 12 populations of 244 individuals in C.conradinae, the temporal and spatial patterns of genetic variation in C.conradinae were investigated, and the effects of genetic drift and differentiation as well as natural environmental factors on the genetic variation and evolutionary distribution of C.conradinae were elucidated. Finally, morphological evidence combined with molecular evidence was used to discuss the species definition of population variation and differentiation. The results showed that Central China, East China and Southwest China were the core regions for the conservation and utilization of germplasm resources of C.conradinae. Support for variant Cerasus conradinae var. ruburm is established. The genetic diversity of C.conradinae was high (Hd = 0.830; Rd = 0.798). There was genetic variation among populations of C.conradinae, and genealogical geographic structure existed among the populations and three geographical groups, but the genetic differentiation coefficient at each level was low. The gene exchange was obvious in Southwest China, and the differentiation was obvious in Central China. The population and three geographic groups do not reject the expectation of expansion model. Two distinct lineages (three geographic groups) were identified from the population of C.conradinae: Central China+ East China lineage and East China+ (Central China+Southwest China) lineage, two lineages of 4.38Mya occurred in the early Pliocene based on geographical isolation. The southeastern part of Eastern China near Mount Wuyi was the most likely refuge for C.conradinae. The results provided a theoretical basis for the classification and identification of C.conradinae and the protection and utilization of germplasm resources.