Canadian Forest Service Publications
A molecular tool for detection and tracking of a potential indigenous Beauveria bassiana strain for managing emerald ash borer populations in Canada. 2014. Johny, S.; Kyei-Poku, G. Journal of Invertebrate Pathology 122:16-21.
Issued by: Great Lakes Forestry Centre
Catalog ID: 35694
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Emerald ash borer is an invasive species from Asia. Beauveria bassiana strain L49–1AA is being tested for the control of emerald ash borer in Canada, using an autocontamination trapping system. We have developed a simplified allele discrimination polymerase chain reaction (PCR) assay to screen B. bassiana strain, L49–1AA from other Beauveria species by targeting the inter-strain genetic differences in 50 end of EF1-a gene of the genus Beauveria. A single nucleotide polymorphism (SNP) site, T?C was identified only in L49–1AA and was used to develop a simplified allele discrimination polymerase chain reaction (PCR) assay based on a modified allelic inhibition of displacement activity (AIDA) approach for distinguishing B. bassiana L49–1AA from all background Beauveria isolates. The SNP site was employed to design inner primers but with a deliberate mismatch introduced at the 30 antepenultimate from the mutation site in order to maximize specificity and detection efficiency. Amplification was specific to L49–1AA without cross-reaction with DNA from other Beauveria strains. In addition, the designed primers were also tested against environmental samples in L49–1AA released plots and observed to be highly efficient in detecting and discriminating the target strain, L49–1AA from both pure and crude DNA samples. This new method can potentially allow for more discriminatory tracking and monitoring of released L49–1AA in our autocontamination and dissemination projects for managing EAB populations. Additionally, the modified- AIDA format has potential as a tool for simultaneously identifying and differentiating closely related Beauveria species, strains/isolates as well as general classification of other pathogens or organisms.
Plain Language Summary
The invasive emerald ash borer (EAB), first detected in North America in 2002, continues to pose a serious threat to ash trees. We conducted surveys to find natural enemies that could be used as possible biological control options. We found that naturally occurring fungi species belonging to Beauveria bassiana had potential for control of EAB and conducted lab tests to determine the most virulent strain(s). We are testing a selected strain, L49–1AA under field conditions using special traps. We developed a molecular marking method that allows for more effective tracking and monitoring of the strain and its persistence after introducing the selected strain, L49–1AA in EAB field populations. The method will also be helpful in identifying and differentiating closely related species, strains or isolates and in general classification of other pathogens.