Pleistocene climate change and the origin of two desert plant species, Pugionium cornutum and Pugionium dolabratum (Brassicaceae), in northwest China
Article first published online: 4 APR 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 199, Issue 1, pages 277–287, July 2013
How to Cite
Wang, Q., Abbott, R. J., Yu, Q.-S., Lin, K. and Liu, J.-Q. (2013), Pleistocene climate change and the origin of two desert plant species, Pugionium cornutum and Pugionium dolabratum (Brassicaceae), in northwest China. New Phytologist, 199: 277–287. doi: 10.1111/nph.12241
- Issue published online: 28 MAY 2013
- Article first published online: 4 APR 2013
- Manuscript Accepted: 22 FEB 2013
- Manuscript Received: 29 JAN 2013
- National Natural Science Foundation of China. Grant Number: 30725004
- Royal Society-NSF China International Joint Project award. Grant Number: 2010/R4
- climate change;
- gene flow;
- interspecific divergence;
- Pugionium ;
- Pleistocene climate change has had an important effect in shaping intraspecific genetic variation in many species; however, its role in driving speciation is less clear. We examined the possibility of a Pleistocene origin of the only two representatives of the genus Pugionium (Brassicaceae), Pugionium cornutum and Pugionium dolabratum, which occupy different desert habitats in northwest China.
- We surveyed sequence variation for internal transcribed spacer (ITS), three chloroplast (cp) DNA fragments, and eight low-copy nuclear genes among individuals sampled from 11 populations of each species across their geographic ranges.
- One ITS mutation distinguished the two species, whereas mutations in cpDNA and the eight low-copy nuclear gene sequences were not species-specific. Although interspecific divergence varied greatly among nuclear gene sequences, in each case divergence was estimated to have occurred within the Pleistocene when deserts expanded in northwest China.
- Our findings point to the importance of Pleistocene climate change, in this case an increase in aridity, as a cause of speciation in Pugionium as a result of divergence in different habitats that formed in association with the expansion of deserts in China.