Submitted to: Mycotaxon
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/24/2006
Publication Date: 4/10/2006
Citation: Huang, B., Li, C., Humber, R.A., Hodge, K.T., Fan, M., Li, Z. Molecular evidence for the taxonomic status of metarhizium taii and its teleomorph, cordyceps taii (hypocreales, clavicipitaceae). Mycotaxon. 94:137-147. Interpretive Summary: This paper addresses the taxonomic status of a Chinese fungus pathogenic to insects, CORDYCEPS TAII, with an asexual (conidial) state named METARHIZIUM TAII. It has been unclear as to whether M. TAII was different from METARHIZIUM ANISOPLIAE var. ANISOPLIAE, one of the most common, widely distributed of all insect pathogenic fungi. Comparisons of gene sequence information between the Chinese C/M TAII isolates and a broad range of isolates from other METARHIZIUM species and varieties indicated that CORDYCEPS/METARHIZIUM TAII differed less from M. ANISOPLIAE var. ANISOPLIAE than did M.A. ANISOPLIAE and other varieties of this species, or than among all available species of METARHIZIUM. This evidence suggests that M. TAII must be treated as a M. ANISOPLIAE var. ANISOPLIAE and, therefore, that CORDYCEPS TAII must be the sexual state for M. ANISOPLIAE var. ANISOPLIAE. This recognition is important for the overall understanding of the biology, taxonomy, and the use of METARHIZIUM species as biological control agents on a wide range of insect pests. Even though the sexual state of any METARHIZIUM forms only rarely in the life histories of these fungi, the reshuffling of its genes through natural sexual processes could have dramatic benefits for improving the prospects for the use of METARHIZIUM as a practical biocontrol agent.
Technical Abstract: The ITS1-5.8S-ITS2 rDNA region from the stroma of CORDYCEPS TAII, mycelium of METARHIZIUM TAII and cultures of M. ANISOPLIAE var. ANISOPLAE from China were amplified, cloned and sequenced. The analysis integrating the data of different strains and varieties of M. ANISOPLIAE and M. FLAVOVIRIDE from GenBank showed that METARHIZIUM TAII should be treated as synonym of M. ANISOPLIAE var. ANISOPLIAE. The ITS1-5.8S-ITS2 rDNA region of C. TAII and M. TAII are identical, indicating that the teleomorph of M. ANISOPLIAE var. ANISOPLIAE is CORDYCEPS TAII.