Unraveling the Genetic Diversity and Phylogeography of the "King of Vitamin C" Fruit (<i>Rosa roxburghii</i> Trattinnick) in Chinese Southwest.

Abstract

The southwestern region of China is one of the last repositories of biodiversity. Exploring the genetic diversity and phylogeographical structure of representative species in this area can not only provide insights into their evolutionary history but also help us specify protection plans. We conducted extensive sampling and combined ISSR, cpDNA (<i>psb</i>A-<i>trn</i>H, <i>atp</i>F-<i>trn</i>H, <i>trn</i>L-<i>trn</i>F, <i>acc</i>D-<i>psa</i>I, <i>trn</i>G-<i>trn</i>S), and single-copy nuclear gene (<i>ncpGS</i> and <i>GAPDH</i>) data with the MaxEnt model to investigate the genetic diversity, phylogeographic pattern and potential distribution of <i>Rosa roxburghii</i> Trattinnick, the "King of Vitamin C" fruit, in this region. The study revealed high genetic diversity within <i>R. roxburghii</i> populations, with Guizhou Province identified as the center of origin. At least two glacial refugia were presented during the Quaternary ice age. The research emphasizes the impact of climate change and geographic isolation on genetic differentiation. This study contributes to the understanding of biodiversity in the southwestern region of China and offers a new perspective on the conservation of wild <i>Rosa roxburghii</i> and other plant resources.