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.

Understanding large-scale patterns of biodiversity and their drivers remains significant in biogeography. Cherries species (Prunus subgenus Cerasus, Rosaceae) are economically and ecologically important in ecosystems and human agricultural activities. However, the mechanisms underlying patterns of species richness-environment relationship in Cerasus remain poorly understood. We collected and filtered worldwide specimen data to map the species richness of Cerasus at the global scale. The map of Cerasus species richness was created using 21043 reliable recorded specimens. The center of Cerasus diversity was determined using spatial cluster analysis. Stepwise regression analysis was carried out using five groups of 21 environmental variables and an integrated model was included to assess the impact of the overall environment. We calibrated each of the four integrated models and used them to predict the global Cerasus species richness and that of the other continents. Our results revealed that Cerasus species have two centers of diversity (the southwest of China and Honshu Island in Japan) with differing environmental variables influencing the distribution patterns of these two centers. In the southwest of China, hydrothermal conditions are the main driving factor while in Japan, habitat heterogeneity is the main driving factor. The relationship between the abundance of the Cerasus and the various groups of factors generally supported both the productivity and the habitat heterogeneity hypothesis. However, these hypotheses did not fully explain the Cerasus species richness pattern, indicating that other factors such as historical environment, topography, and human activities likely played a role in pattern formation. The high level of habitat heterogeneity and better hydrothermal conditions may have played an important role in the establishment of its globally consistent richness-climate relationship. Our results can provide valuable information for the classification, and conservation of Cerasus natural resources, as well as contribute to furthering our understanding of biogeography at a global scale.

Cerasus serrulata (Rosaceae) is an important flowering cherry resource. It is almost the most widely distributed species in the genus, mainly included in the subtropical and temperate China, which enables the geographic evolutionary pattern to be a representative. Besides, the morphological traits are greatly varied especially in ornamental characters. All of these makes Cerrasus serrulata a valuable research object. Thus, phylogeographic analysis was conducted to apprehend the spatial pattern and evolutionary history, which can also add insights into the phylogeography of the genus Cerasus and plants in subtropical and temperate China, as well as to deeper understand the genetic diversity and structure of the germplasm to make better and more effective utilization. A total of 327 individuals of 18 populations were collected. Three cpDNA fragments (matK, trnD-E, trnS-G) and the nuclear internal transcribed spacer (ITS) were utilized. The result showed a high genetic diversity both in species level and population level of Cerrasus serrulata. The high genetic differentiation among populations and the existence of phylogeographic structure in whole were detected. In addition, no bottleneck was identified. The the distribution pattern and center were formed before the LGM. Two geographical lineages were inferred. One was confined to Qingling Mountain and Taihang Mt. The other was from the Wuling Mt to Lu-Huang Mt, and then went northeast to the coast of Asia. Besides, taxonomic treatments of the Cerasus serrulata complex were reconsidered.