A taxonomic revision of Metarhizium based on a phylogenetic analysis of rDNA sequence data

The taxonomy of Metarhizium has been reassessed using sequence data and RAP D patterns from 123 isolates recognised as M. anisopliae, M. flavoviride or M. album. A high level of genetic diversity was found which was best resol ved at the species/variety level by sequence data from the TTS and 28S rDNA D3 regions. RAPD patterns correlated closely with the sequence data and re vealed a much greater degree of diversity useful for distinguishing strains within a variety. Ten distinct clades were revealed by the cladogram based on the combined sequence data set. Several major evolutionary lines were r evealed, but the taxonomic relationships at the base of the tree are poorly resolved. The data support the monopoly of the M. anisopliae group, and re cognise four clades within it. Two correspond with M. anisopliae var, aniso pliae and M. anisopliae var. majus. The other two are described as new vari eties based on their distinctive ITS sequence data: M. anisopliae var. lepi diotum and M, anisopliae var. acridum vars nov. M. album, M. flavoviride va r. flavoviride and M, flavoviride var. minus are recognised and redefined a ccording to ITS sequence data. Three clades represent two new varieties, M. flavoviride var. novazealandicum and M. flavoviride var. pemphigum vars no v, based on their distinct ITS sequence data. The third, with two isolates, has not been named pending further data.