Studies On The Characteristics Of The Strains Isolated From The Fruit Body Of Cordyceps Sinensis

In this thesis,the basic situation of Cordyceps sinensis was firstly summarized.Then the biological characteristics of Ophiocordyceps sinensis,anamorphic research of Cordyceps sinensis and adwance of the fungirelated to Cordyceps sinensis were reviewed.Due to the Ophiocordyceps sinensis has not yet achieved complete verification by Koch’s law as the fungus of the Cordyceps sinensis.This study aimed at settling the controvers by investigating the characteristics of the strains of fungi from Cordyceps sinensis.The fruiting body of fresh Cordyceps sinensis was used as experimental material for tissue and single spore separation to obtain the Ophiocordyceps sinensis strains and the other fungal strains.Preliminary morphological description and ITS sequence identification were carried out to determine species information.The basic biological characteristics of the new discovered strains and the relationship between the strains and Ophiocordyceps sinensis were studied.The rate of infection to the bat moth larvae was also studied.The main achievements of this study were as follows:1.A simple and efficient method for the isolation of ascospores of Cordyceps sinensis-spot marking method was invented.2.Several strains of Ophiocordyceps sinensis were isolated by tissue isolating and 115 strains from ascospores were isolated.3.Five new strains beside Ophiocordyceps sinensis were isolated and identified,among which TB-1 was Penicillium chrysogenum,TB-3 and TB-4 were Cladosporium.FD is Fusarium and MR-1 may be an unknown new species with less public reports.4.The basic biological characteristics of 5 fungi strains were studied,The optimum temperature,pH,carbon source and nitrogen source were determined.5.The relationship between 5 fungi strains and Ophiocordyceps sinensis was studied.The results showed that 5 strains could inhibit Ophiocordyceps sinensis through space and nutritional competition.The inhibition would decrease as the advance of inoculation for Ophiocordyceps sinensis.6.The infection tests of the five strains of fungi to the larvae of the bat moth were carried out.The results showed that all the five strains could infect the larvae.The rates of infection were MR-1(73.3%),TB-3(60%),TB-4(65%),TB-1(64%)and FD(70%).7.MR-1,TB-3,TB-4,TB-1 and FD belong to fungi related to Ophiocordyceps sinensis.