Arctic plant origins and early formation of circumarctic distributions: a case study of the mountain sorrel, Oxyria digyna

• Published in: The New phytologist Vol. 209; no. 1; pp. 343 - 353
• Main Authors: Wang, Qian, Liu, Jianquan, Allen, Geraldine A, Ma, Yazhen, Yue, Wei, Marr, Kendrick L, Abbott, Richard J
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.01.2016; New Phytologist Trust; Wiley Subscription Services, Inc
• Subjects: ancestral location; arctic flora; Arctic Regions; Atlantic Ocean; Base Sequence; case studies; China; circumarctic distribution; DNA; Europe; flora; genes; Genetic Variation; Greenland; migration; Molecular Sequence Data; mountains; North America; Oxyria digyna; Phylogeography; Plastids - genetics; Polygonaceae - genetics; population growth; population size; Russia; Sequence Analysis, DNA; sorrel; species origin; temperature; Tibet; Eurasia; Arctic region; Atlantic Ocean; China; North America; Greenland; Russia; Western European region; Arctic Regions; Europe; Tibet; migration; species origin; ancestral location; circumarctic distribution; arctic flora
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.13568

Many plant species comprising the present‐day Arctic flora are thought to have originated in the high mountains of North America and Eurasia, migrated northwards as global temperatures fell during the late Tertiary period, and thereafter attained a circumarctic distribution. However, supporting evidence for this hypothesis that provides a temporal framework for the origin, spread and initial attainment of a circumarctic distribution by an arctic plant is currently lacking. Here we examined the origin and initial formation of a circumarctic distribution of the arctic mountain sorrel (Oxyria digyna) by conducting a phylogeographic analysis of plastid and nuclear gene DNA variation. We provide evidence for an origin of this species in the Qinghai‐Tibet Plateau of southwestern China, followed by migration into Russia c. 11 million yr ago (Ma), eastwards into North America by c. 4 Ma, and westwards into Western Europe by c. 1.96 Ma. Thereafter, the species attained a circumarctic distribution by colonizing Greenland from both sides of the Atlantic Ocean. Following the arrival of the species in North America and Europe, population sizes appear to have increased and then stabilized there over the last 1 million yr. However, in Greenland a marked reduction followed by an expansion in population size is indicated to have occurred during the Pleistocene.