Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (9): 1084-1094.DOI: 10.3773/j.issn.1005-264x.2010.09.009

• Research Articles • Previous Articles     Next Articles

Population genetic diversity of Rhodiola dumulosa in Northern China inferred from AFLP makers

ZHANG Yun-Hong; HOU Yan; and LOU An-Ru*   

  1. State Key Laboratory of Earth Surface Processes and Resource Ecology (Beijing Normal University), College of Life Sciences of Beijing Normal University, Beijing 100875, China
  • Received:2009-11-27 Online:2010-09-01 Published:2010-10-08
  • Contact: LOU An-Ru

Abstract: Aims Rhodiola dumulosa (Crassulaceae) is a perennial herbaceous plant. It grows among rocks on mountains at 1 600–3 900 m, and its populations are spatially scattered in their areas of distribution. Our objectives were to study the population genetic diversity and genetic structure of R. dumulosa in northern China and determine relationships between genetic diversity and environmental factors. Methods We analyzed 776 individuals from 25 natural populations using amplified fragment length polymorphism (AFLP) markers. Important findings We obtained 398 unambiguous bands from the four pairs of selective primers, 312 bands (78.46%) of which were polymorphic across all individuals. The Nei’s gene diversity was 0.364 9, and the Shannon’s information index was 0.542 2 at the species level. Therefore, there was a high level of genetic diversity within R. dumulosa populations in northern China. The population genetic differentiation index Gst was 0.150 7, and the indirect estimate of gene flow Nm was 2.82, which indicated that genetic differentiation among northern populations was low and gene exchange was frequent. Analysis of molecular variance (AMOVA) revealed that the majority of AFLP variations resided within populations (67.9%). The STRUCTURE and UPGMA cluster analyses showed that the closely related populations are geographically restricted and occur in proximity to each other. This result was confirmed by the Mantel test, which revealed a significant positive correlation (r = 0.512 9, p < 0.001) between geographical distance and genetic distance. In addition, the correlation analysis of population genetic diversity and altitude showed a significant negative relationship (p < 0.05), i.e., population genetic diversity decreased with increasing altitude. However, there was no significant correlation between genetic diversity and slope direction. The software Dfdist was used to detect outliers caused by altitude, but the results were non-significant. All research results showed that geographical distance affected genetic distance significantly.