Genetic variation among Stipa grandis P. Smirn populations with different durations of fencing in the Inner Mongolian Steppe

• Published in: The Rangeland journal Vol. 32; no. 4; pp. 427 - 434
• Main Authors: Wu, Jian-bo, Gao, Yu-bao, Bao, Xiao-ying, Gao, Hui, Jia, Mei-qing, Li, Jie, Zhao, Nian-xi
• Format: Journal Article
• Language: English
• Published: Collingwood, Victoria: CSIRO Publishing 2010
• ISSN: 1036-9872; 1834-7541
• DOI: 10.1071/RJ09038

The genetic structure of a population should be carefully considered in ecological restoration because it may play a critical role in maintaining the persistence of a restored ecosystem. In the present study, we examined genetic diversity and genetic structure of Stipa grandis P. Smirn populations from fenced and grazed plots using amplified fragment length polymorphism markers. Molecular genetic variation showed that the genetic diversity of the fenced populations was greater compared with the overgrazed population. There was a significant variation among the populations (Fst=0.3689, P<0.001) by AMOVA analysis, and the gene flow was 0.4039 among the populations. The results from a comparison of limited morphological characteristics and from an unweighted pair group method with arithmetic mean cluster analysis and non-metric multi-dimensional scaling analysis suggested that genetic differentiation had occurred between the fenced populations and the grazed populations. The largest genetic diversity was in the moderately grazed population, which might be related to higher population density and greater sexual reproduction due to less disturbances in the plots. The genetic diversity of the long-term (24 years) fenced population was similar to that of a short-term fenced population (fenced for 11 years). These results suggested that the genetic diversity in the overgrazed population might be increased to some extent through fencing, but this effect did not occur beyond 11 years.