Distinguishing Ophiostoma ips and Ophiostoma montium,two bark beetle-associated sapstain fungi

Two synonymous sapstain species, Ophiostoma montium and Ophiostoma ips, which are vectored by Dendroctonus ponderosae and various bark beetles, respectively, were differentiated into separate species using growth and molecular characteristics. Analysis of 32 isolates of the two species from different countries showed that O. ips was able to grow at 35 degrees C while O. montium was not. This growth-based differentiation was strongly supported by sequence data for the internal transcribed spacer (ITS), 5.8S and partial 28S rDNA, and the beta-tubulin genes. The beta-tubulin gene sequence data indicate that the two species can easily be differentiated with a single polymerase chain reaction (PCR) assay.