Biogeographical divides delineated by the three‐step landforms of China and the East China Sea: Insights from the phylogeography of Kerria japonica

• Published in: Journal of Biogeography
• Main Authors: Luo, Dong, Xu, Bo, Li, Zhi‐Min, Sun, Hang
• Other Authors: National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Ecology; Ecology, Evolution, Behavior and Systematics; Bering Land Bridge
• Online Access: http://dx.doi.org/10.1111/jbi.14002; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jbi.14002; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jbi.14002

Abstract Aim East Asia exhibits complex geomorphological and climatic characteristics. The aim of this study was to test whether the so‐called three‐step landforms of China, together with the East China Sea (ECS), have acted to shape specific phylogeographical patterns and affected the biogeographical history of the species belonging to the East Asian Flora. Location China and Japan. Taxon Kerria japonica (L.) DC. Methods Three chloroplast DNA regions and 15 nuclear microsatellite (nSSR) loci were sequenced and genotyped in 576/450 individuals of K. japonica . Phylogeographical analyses were performed to assess the genetic structure, historical gene flow and demographical history of these individuals, and climatic factors were examined to determine their effects on phylogeographical breaks. Furthermore, time‐calibrated phylogenetic trees and ancestral range reconstruction were used to infer the biogeographical history of K. japonica . Potential habitats at present and during the last glacial maximum (LGM) were identified using ecological niche modelling. Results Distinct phylogeographical breaks were found across the ECS and along the boundary of the three‐step landforms of China. Low historical gene flow and significant climatic differences were detected in each pair of adjacent regions. The results of molecular dating and ancestral range reconstruction indicated that K. japonica originated in North America during the mid‐Miocene (14.76 Ma), and intra‐specific diversification began in the late Miocene (7.78 Ma). Compared to the relatively stable distribution range of Chinese populations, Japanese populations experienced range expansion after the LGM in response to Quaternary climate change. Main conclusions Kerria japonica has a complex biogeographical history, with a mid‐Miocene origin in North America and subsequent migration into East Asia via the Bering land bridge. The onset of intra‐specific diversification was probably associated with Asian monsoon intensifications, while exposure to the ECS floor ...