Submitted to: Molecular Ecology Resources
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/6/2012
Publication Date: 1/14/2013
Citation: Kepler, R.M., Rehner, S.A. 2013. Genome-assisted development of nuclear intergenic sequence markers for entomopathogenic fungi of the Metarhizium anisopliae species complex. Molecular Ecology Resources. 13:210-217. Interpretive Summary: Fungi can be effective in controlling insects that damage agricultural crops without the use of harmful chemicals. One group of fungi is especially important as a source of biological control agents. Within this fungal group each biocontrol strain must be well characterized and selected for use on a narrow range of insects. Molecular markers, specifically small segments of the fungal genome, are used to characterize these biocontrol fungi. In this research seven new molecular markers were developed and tested to determine which ones were most effective for characterizing strains of insect fungi. Insect pathologists will use this research to characterize the strains of fungi most effective in controlling insects as well as to track the released fungi in the environment.
Technical Abstract: Entomopathogenic fungi in the genus Metarhizium have proven useful for the biological control of economically important pests across the globe. Understanding the true diversity of this group is hampered by convergent morphologies between species. The application of molecular techniques has enabled greater resolution of species than allowed by morphology alone. In particular, the commonly used biocontrol agent M. anisopliae was found to be a species complex composed of nine species. This work was conducted with commonly used markers in fungal phylogenetics (BTUB, RPB1, RPB2 and TEF), which likely underrepresent diversity in the M. anisopliae complex. Using sequence data from the genomes of M. acridum and M. robertsii we identified regions of conserved gene synteny and developed primers to amplify intergenic regions of seven loci. Using ex-type and authenticated tissue for species in the M. anisopliae complex, we demonstrate that sequence data derived from intergenic loci is more phylogenetically informative than previously available markers. These new markers will enable investigations at or below the species level for the M. anisopliae complex.