Abstract Detail

Population Genetics

Taerum, Stephen Joshua [1], Duong, Tuan A. [1], de Beer, Z. Wilhelm [2], Wingfield, Michael J. [1].

The worldwide movement of the fungus Leptographium procerum, symbiont of the red turpentine beetle.

Leptographium procerum is an ophiostomatoid fungus that infects pine trees in various parts of the world, and is vectored by a wide variety of root-colonizing weevil and bark beetle species. This fungus causes blue staining in infected trees, and has been suggested to contribute to the aggressive tree-killing behaviour of the invasive red turpentine beetle (Dendroctonus valens) in China. We used mating type loci and microsatellites to assess the global diversity of L. procerum, to determine its native range, and to examine the movement history of the fungus. The population of L. procerum in China showed a bias towards mating type MAT1-1, while the other populations showed no bias. Leptographium procerum had the highest genetic diversity in Europe, followed by North America and China. The population in North America was the only population in linkage disequilibrium. A median-joining network grouped the Chinese haplotype with some European haplotypes, while intermixing the European and North American haplotypes. Clustering analyses using DAPC demonstrated the presence of four genetic clusters. One cluster contained the haplotypes from China and a few from Europe, while the remaining clusters contained a mixture of haplotypes from Europe and North America. Based on these results, we conclude that the population of L. procerum in Europe is most likely native, and is likely the source of the L. procerum populations in North America and China. This is in contrast to previous assumptions that the fungus is native to North America.

1 - University of Pretoria, FABI, Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria, 0028, South Africa
2 - University of Pretoria, FABI, Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private bag X20, Pretoria, 0028, South Africa

Keywords:
Microsatellites
Mating-type loci
Network analyses
biological invasions
symbiosis
Forestry.

Presentation Type: Oral Paper:Papers for Topics
Session: 71
Location: Salon 6/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 4:00 PM
Number: 71010
Abstract ID:397
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student