Current Understanding of Molecular Systematics of Cordyceps

Recent development of molecular systematics of Cordyceps is reviewed.Phylogenetic studies have shown that Clavicipitaceae and other families of Hypocreales form a monophylogenetic group and that Cordyceps is closely related to other genera of Clavicipitaceae.Molecular research indicates that Cordyceps is a polyphyletic taxon with members of the genus forming several clades in rDNA sequence analyses.Among the subdivisions of the genus, only Cordyceps subgen.Neocordyceps appears to be monophyletic.A suggestion is that Cordyceps evolved in association with their hosts and that shifts between distantly related hosts occurred several times in the course of evolution.Type I intron in the large and small sub-unites of nuclear rDNA has been found in different lineages of Cordycpes species and the inserting positions of the intron are closely related to the phylogeny of Cordyceps hosts.Several independent DNA sequence analyses support C.crassispora, C.gansuensis, C.multiaxialis, C.nepalensis and C.sinensis to be the same species because they share similar ITS sequences.RAPD and ITS analyses reveal genetic variation among C.sinensis populations from different locations of the Tibetan Plateau.Molecular methods have provided firm evidence which establishes the connection between the anamorphic and teleomorphic states of Cordyceps.Beauveria brongniartii, B.sobolifera, Hirsutella sinensis, Metarhizium anisopliae var.majus, Mariannaea pruinosa and Paecilomyces hawkesii have been determined to be the anamorph of C.brongniartii, C.sobolifera, C.sinensis, C.brittlebankisoides, C.pruinosa and C.gunnii respectively.Sampling number and scope and the selection of samples have strong effects on the molecular results.Application of molecular markers in different research subjects and relationships between the anamorphs and teleomorphs are also discussed.