Canadian Forest Service Publications
Determining fungal diversity on Dendroctonus ponderosae and Ips pini affecting lodgepole pine using cultural and molecular methods. 2006. Lim, Y.W.; Kim, J.-J.; Lu, M.; Breuil, C. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Mountain Pine Beetle Initiative Working Paper 2006-04. 20 p.
Available from: Pacific Forestry Centre
Catalog ID: 26284
CFS Availability: PDF (download)
Several beetles (Coleoptera: Scolytidae) and their fungal associates cause severe damage to lodgepole pine in Western Canada and the northwestern United States. The fungus diversity from the surface of two bark beetle species, Dendroctonus ponderosae Hopkins (mountain pine beetle) and Ips pini Say (pine engraver), was surveyed using cultural and molecular methods. Nine fungal taxa were recognized by morphological characterizations. All nine taxa were isolated from the mountain pine beetle, whereas only seven of the nine taxa were isolated from the pine engraver. The identification was based on cultural morphology and high sequence similarities of the internal transcribed spacer (ITS) and large subunit ribosomal DNA (large subunit rDNA) region to sequences of known fungi. Fungal ITS regions were amplified from DNA directly extracted from the beetle surface. The PCR products were cloned and 250 clones were classified by their restriction pattern with HaeIII and RsaI. A total of 26 RFLP types were identified and subsequently sequenced. Among them, 15 RFLP (restriction fragment length polymorphism) types were identified as being present in mountain pine beetle and 14 were present in pine engraver. Sequence analysis of the RFLP types showed that 23 ascomycetes and 3 basidiomycetes were represented in the clone libraries, whereas the isolates from the cultural method represented 7 ascomycetes and 2 basidiomycetes. We found that yeast and non-staining filamentous euascomycetes fungi were detected efficiently using a molecular approach, while the major sap-staining fungi and decay fungi were best detected using cultural methods.