Studies On Molecular Systematics Of Several Rare Cordyceps And Their Allies

Cordyceps and related fungi include over500species around the world in2010,and approximately130have been reported in China. So, researching the resources ofCordyceps and understanding every useful species have a significant meaning.Several rare Cordyceps have been described in this investigation, and meanwhile theiranamorphs isolated from specimens by ascospores were also described and identified.Some phylogenetic studies have been conducted to test and refine the classification ofthese species.According to the multi-gene phylogeny of Sung et al., neither Cordyceps nor thefamily Clavicipitaceae is monophyletic. The genus Cordyceps was divided into fourgenera, i.e. Cordyceps s. s., Metacordyceps, Elaphocordyceps and Ophiocordyceps. Inthis paper, the classification of these species was studied by ribosomal DNA,combining with morphology research. The main results are reported as follows:The ascospores of Cordyceps nelumboides do not disarticulate into part-sporesand microcycle conidiation have been found. The anamorph of C. nelumboides maybe an Akanthomyces sp.A strain isolated from ascospores of Ophiocordyceps clavata was determined tobe its anamorph. The phylogenetic tree based on analysis of18S rDNA sequenceindicated that O. clavata belongs to the genus Ophiocordyceps，and its anamorph wasa Hirustella sp.A special Cordyceps pruinosa was found and the morphological features of itsanamorph were described. The host was an adult of musca in Order Diptera.A species isolated from ascospores of Cordyceps kusanagiensis was determinedto be its anamorph and its real taxonomic status need further study. The phylogenetictree based on analysis of ITS sequence indicated that C. kusanagiensis belongs to thegenus Metacordyceps.