PHYLOGENY OF METARHIZIUM SPECIES AS DETER MINED BY PARTIAL RIBOSOMAL RNA SEQUENCES
由部分核糖体RNA序列确定的绿僵菌属种系统发育关系

This study used dideoxy nucleotide chain termination method and specific oligonucleotide primers to determine partial sequences of selected regions from small (18S) and large (25S) subunit rRNAs of species of Metarhizium. The aligned sequences were calculated for nucleotide differences. Phylogenetic relationships among species were analyzed by the maximum-likelihood procedure. The taxa cluster into two main groups: among cylindrical conidiogenous-cell forming species, M. anisopli-ae var. anisopliae, M. anlsopliae var. majus, M. brunneum (NRRL 1944), M. guiz-houense, M. pingshaense and unknown species M. sp. 2 constitute a closely related group distinguishable from M. anisopliae (ACCC 30104); of the clavate conidiogenous-cell forming species, M. album, M. cylindrosporae and M. flavoviride are well separated from one another. Our results do not support classification schemes that accept only M. anisopliae and M. jlavoviride in Metarhizium. The phylogenetic value of taxonomical criteria is discussed.