Studies On The Relationship Between The Strains Related To Ophiocordyceps And Hirsutella Sinensis

This paper reviewed the research progress on Ophoicordyces sinensis resource distribution, life history, chemical composition and pharmacological properties, asexual type and other aspects of discovery. Although Ophiocordyceps sinensis has been recognized as fungus by most reseachers, there was no accurate test to prove the number of species of fungi involved in the formation process of Ophiocordyceps sinensis. Author propose an concept of strains related to Ophiocordyceps(SRO), which were those strains isolated from wild Ophiocordyceps sinensis having effect on Ophiocordyceps sinensis and can infect Hepialidae larva. In the experiments, 6 SROs, had been isolated previously, were tested to investigate the relationship between Ophiocordyceps sinensis and these strains.Firstly, DNA were extracted from different parts of fresh wild Ophiocordyceps sinensis with the different growth stages. The sequences of products of PCR with general primer of Its1/Its4 were checked in order to verify whether the total DNA contained strains related to Ophiocordyceps. Then, the relationship between Ophiocordyceps sinensis and SRO were researched by cultivating Ophiocordyceps sinensis with a couple of SRO together, adding fermen liquent of SRO to Ophiocordyceps. Finally, infect experiments were tested using the mixed of SRO and Ophiocordyceps sinensis with Hepialidae larva in order to investigating the infection rates.The Major results as following:(1)The Ophiocordyceps sinensis was the most fungus that easily detected with conventional PCR in different growth stages and different parts.(2)In the confront tests with SRO and Ophiocordyceps sinensis, it was found there inhibition slightly ranging 4.0-9.0% in the 21 groups of combination of two SROs when Ophiocordyceps sinensis was inoculated 10 days ahead. The inhibitory rates become smaller when Ophiocordyceps sinensis inoculated 20 days and 30 days ahead(P<0.05). Some combinations of SRO were promoting growth of Ophiocordyceps sinensis even.(3)The dry weight in liquid and diameter on solid medium cultivate of Ophiocordyceps sinensis were increase as the amount of fermentation liquid of SROs. Though there were different promoting effects, it demonstrated there were no inhibitory matters in the fermentation liquid of SRO. It suggests that nutritional competition rather than antagonistic action was the reseason of inhibitory effect.(4)The infection rates that SRO mixed with Ophiocordyceps sinensis infected the Hepialidae larva were between the infection rate of SRO and Ophiocordyceps sinensis individually, ranging from 10% to 50%.