Biodiv Sci ›› 2012, Vol. 20 ›› Issue (2): 224-230.  DOI: 10.3724/SP.J.1003.2012.07214

• Original Papers • Previous Articles     Next Articles

Genetic diversity of Armillaria gallica isolates from China and Europe revealed with ISSR analysis

Lifu Sun1,*(), Kequan Pei2, Yanhua Zhang1, Jun Zhao3, Guoting Yang4, Guofu Qin3, Yushuang Song3, Ruiqing Song4   

  1. 1 College of Life Sciences, Shaoxing University, Shaoxing, Zhejiang 312000
    2 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093
    3 General Station of Forest Pest Management, State Forestry Administration, Shenyang 110034
    4 School of Forestry, Northeast Forestry University, Harbin 150040
  • Received:2011-11-24 Accepted:2012-02-28 Online:2012-03-20 Published:2012-04-09
  • Contact: Lifu Sun


Armillaria gallica is a cosmopolitan fungal species found in the northern hemisphere, and genetic diversity and similarity between different continental isolates of the species can reveal important large-scale biogeographical patterns. A total of 79 isolates of A. gallica were collected from Europe and China. We estimated the genetic diversity of these isolates using ISSR (inter-simple sequence repeat) markers. Six ISSR primers were employed to identify a total of 210 scorable fragments, of which 202 (96.2%) were polymorphic loci (frequecy<0.95). The average number of polymorphic loci detected with each primer was 33.6. The results indicated that ISSR markers can reflect abundant polymorphism in Armillaria. According to UPGMA clustering analysis, 49 out of 53 Chinese A. gallica isolates clustered into a China Group at the 0.773 similarity level. The genetic divergence of European isolates was significantly higher than predicted; these isolates were clustered into Europe Group A and Group B at the 0.775 and 0.763 similarity level, respectively. The similarity coefficient between the two European groups was only 0.738, but it was 0.770 between China Group and Europe Group A. Some isolates from China and Europe had experienced obvious genetic divergence, and several isolates had lower intraspecific similarity coefficients than interspecific similarity coefficient found in other Armillaria biological species. Our results indicated that considerable genetic differentiation existed between European and Chinese isolates due to geographic isolation, and that these isolates were in the process of allopatric speciation. The differentiation among isolates of A. gallica from Europe was more evident, and Europe is possibly the place of origin for isolates of the species.

Key words: Armillaria gallica, genetic diversity, genetic similarity, clustering analysis, geographic isolation