Genetic variation characterization of the boreal tree Acer ginnala population in response to environmental change of Northern China

Abstract

Background: Acer ginnala is a deciduous shrub/small tree that primarily distributed across the northern regions of China. It comprises a foundation species in many terrestrial ecosystems and has significant ornamental and economic value. Owing to its increased use as an economic resource, overexploitation and environmental destruction have resulted in the vulnerability of this species. Thus, the elucidation of the genetic differentiation and influence of environmental factors on A. ginnala is very critical for its management and future utilization strategies. Results: Our results revealed that high genetic variation occurred in A. ginnala species while low genetic diversity was observed at the population level. Most differentiation has found among populations. A significant correlation existed between genetic and environmental distances. Seven climate variables (bio1, bio2, bio3, bio4, bio13, bio15 and bio18) might explain the substantial levels of genetic variation (> 40%) in populations. The most suitable areas of this species appeared in Shaanxi, Shanxi, Anhui Provinces, and Northeastern China based on ENM results. Compared to the last interglacial (LIG) period, A. ginnala migrated toward Northern and Northeastern China, and extended to the most suitable areas during the last glacial maximum (LGM) period. Shanxi and Anhui Provinces might have served as refugium owing to their relatively high genetic variation. Conclusions: Low genetic diversity at the population level that may be the source of its vulnerability. Climate heterogeneity would play an important role in the pattern of genetic differentiation in A. ginnala populations. The A. ginnala population was isolated by a heterogeneous climate and subsequently began to adapt to local selection processes resulted in high genetic divergence.