Evolutionary History of Rhus chinensis (Anacardiaceae) From the Temperate and Subtropical Zones of China Based on cpDNA and Nuclear DNA Sequences and Ecological Niche Model.

Yukang Liang,Yang Zhang,Zhumei Ren,Xu Su,Jun Wen

doi:10.3389/fgene.2019.00171

Abstract

To explore the origin and evolution of local flora and vegetation, we examined the evolutionary history of Rhus chinensis, which is widely distributed in China’s temperate and subtropical zones, by sequencing three maternally inherited chloroplast DNAs (cpDNA: trnL-trnF, psbA-trnH, and rbcL) and the biparentally inherited nuclear DNA (nuDNA: LEAFY) from 19 natural populations of R. chinensis as well as the ecological niche modeling. In all, 23 chloroplast haplotypes (M1–M23) and 15 nuclear alleles (N1–N15) were detected. The estimation of divergence time showed that the most recent common ancestor dated at 4.2 ± 2.5 million years ago (Mya) from cpDNA, and the initial divergence of genotypes occurred at 4.8 ± 3.6 Mya for the nuDNA. Meanwhile, the multimodality mismatch distribution curves and positive Tajima’s D values indicated that R. chinensis did not experience population expansion after the last glacial maximum. Besides, our study was also consistent with the hypothesis that most refugia in the temperate and subtropical zones of China were in situ during the glaciation.

Highlights

The Quaternary climate oscillations occurred in the past ca. 2.58 million years ago (Mya) have resulted in several glacial and interglacial cycles in the Northern Hemisphere (Shackleton and Opdyke, 1973)
It is less well known whether population genetic diversification of plants within the warm temperate zone or within the glacial refugia is due to isolation on a heterogeneous landscape or adaptation and selection along ecological gradients (Su et al, 2015; Zhao et al, 2016)
Our results showed that the range of R. chinensis had increased since the LGM (Figure 3) but did not support a rapid expansion based on the mismatch distribution (Figure 1) and Tajima’s D (1.19, 0.05 < P < 0.10 for chloroplast DNAs (cpDNA); 2.37, P < 0.01 for nuDNA)

Summary

Introduction

The Quaternary climate oscillations occurred in the past ca. 2.58 million years ago (Mya) have resulted in several glacial and interglacial cycles in the Northern Hemisphere (Shackleton and Opdyke, 1973). 2.58 million years ago (Mya) have resulted in several glacial and interglacial cycles in the Northern Hemisphere (Shackleton and Opdyke, 1973) These climatic alterations have left imprints in geographical distributions, population structures, and demographic histories of plant and animal species (Abbott et al, 2000; Avise, 2000; Hewitt, 2004, 2011; Qiu et al, 2011, 2013; Wen et al, 2014, 2016), which can be traced by analyses of genetic variations within and between extant populations (Abbott et al, 2000; Johansen and Latta, 2003; Hewitt, 2004). More phylogeographic studies of additional plant species within the warm temperate refugial regions are necessary in order to detect their spatial geographic patterns and to assess the underlying causes

Methods

Results

Discussion

Conclusion