Molecular Phylogeography Analysis Reveals Population Dynamics and Genetic Divergence of a Widespread Tree Pterocarya stenoptera in China

Abstract

The geological events, past climatic fluctuations, and river systems played key roles in the spatial distribution, population dynamics, and genetic differentiation of species. In this work, we selected Pterocarya stenoptera, a widespread tree species in China, to test the roles of these factors. Four noncoding spacers, eight microsatellite (simple sequence repeat) markers, and species distribution modeling were used to examine the phylogeographical pattern of P. stenoptera. Based on chloroplast DNA data, populations of P. stenoptera were clearly clustered into three groups. The divergence time of these groups fell into the stage of the Qinghai–Tibet Movement, 1.7–2.6 Ma. For simple sequence repeat data, only one western marginal population YNYB could be separated from other populations, whereas other populations were mixed together. Our results indicated that the environmental heterogeneity resulting from the Qinghai–Tibet movement might be response for this genetic divergence. The climatic fluctuations in the Pleistocene did not cause the substantial range shift of P. stenoptera, while the fluctuations affected its population size. Moreover, we also confirmed the river systems did not act as channels or barrier of dispersal for P. stenoptera.

Landscape genomics reveals genetic evidence of local adaptation in a widespread tree, the Chinese wingnut (Pterocarya stenoptera)

“…However, phylogeographic inference of P. stenoptera revealed three independent groups among the Chinese populations. In addition, it was suggested that past climate change and gene flow might have together determined the genetic structure of P. stenoptera (Qian et al, 2019). Here, our analyses revealed three independent genetic structures that are widely observed in other species (Gugger et al, 2011;Yu & Nason, 2013;Fu et al, 2014).…”

“…Identification of population genetic structure at the genome-wide level can help to understand how these factors affected the formation of genetic structure. Recently, two studies have reported the population genetic structure of P. stenoptera (Li et al, 2018;Qian et al, 2019). The study of landscape genomics of P. stenoptera showed that populations in China were weakly subdivided into two groups, and environmental variables related to ecological niche play important roles in shaping population genetic structure (Li et al, 2018).…”

“…This species is also an important garden plant and is widely used as street tree. In previous phylogeographical studies of P. stenoptera, it was inferred that there has been no significant change in the species' distributional range in response to climate fluctuations during the Pleistocene, with only minor fluctuations in population size during that period (Qian et al, 2019). This suggests that the species responded to environmental fluctuation through a combination of local adaptation and phenotypic plasticity.…”

Transcriptomic responses to drought stress among natural populations provide insights into local adaptation of weeping forsythia

“…In recent common garden experiments, Arabidopsis halleri in metal-contaminated areas expressed adaptive differentiation in gene expression in response to high zinc stress, which indicates the differentiation of adaptive strategies among populations [ 10 ]. Under the same cultivation conditions, Ricotia lunaria showed significant differentiation of gene expression among different natural populations [ 11 ]. These studies indicate constitutive expression differences among different populations, even among those that are found in the same conditions or face to the same stresses.…”

Historical migration and taxonomic entity of Korean endemic shrubLespedeza maritima(Fabaceae) based on microsatellite loci

“…Climatic oscillations and changes in geography associated with the Quaternary are generally considered to have been the main driver governing the region’s present plant distributions ( Hewitt 2004 ). During the last few decades, many studies on the genetic diversity and structure of plant species have sought to check this suggestion around East China Sea (ECS) ( Qiu et al 2009 ; Xu et al 2015 ; Tang et al 2017 ; Qian et al 2019 ). Such studies mainly have focused on Chinese or Japanese plants, or both.…”