Abstract

In the fungal genus Cordyceps, the type species C. militaris produces bioactive ingredients and exhibits medicinal effects as a Traditional Chinese Medicine (TCM). Currently, the fruiting-body of C. militaris has been artificially mass-produced as functional food and medicine in China. The unstable variation in forming fruiting-body is however a restriction in the production. The genetic study on perithecial stromata (fruiting-body) formation in vitro of C. militaris has not yet been reported. In this study, we reported the effect of genetic variation including possession of the mating system on perithecial stromata formation of C. militaris. The results showed that the mono-conidial isolates with both MAT1-1-1 and MAT1-2-1 (genotype MAT1-1/2) produced stromata. While the isolates having only either MAT1-1-1 or MAT1-2-1 failed to produce stromata. Despite obvious heterothallism, homothallism was occasionally observed in a few isolates of C. militaris. Genetic variation was observed amongst the different mono-conidial isolates of C. militaris. The unstable variation or loss of fruiting-body formation was caused by the inner-specific genetic variation.

Key words: Cordyceps militaris, molecular genetics, genetic variation, homothallism, heterothallism, fruiting-body.