Ophiocordyceps Spp. And The Diversity Of Fungi Associated With It In Gansu Province

Ophiocordyceps sinensis is a specific traditinal chinese medicine.It is mainly distributed in Qinghai-Tibetan Plateau, include Tibet, Qinghai, Gansu, Sichuan, Yunnan Province, and marginal region of Himalaya, such as Nepal, the Kingdom Bhutan and India.The marginal region of northern of Qinghai-Tibetan Plateau and the end of Qilian Mountain is major producing region of Gansu Province, hold in store 8100 Kg per year. Gannan Tibetan Autonomous Prefecture is major producing region of Gansu Province, the yield of Ophiocordyceps sinensis are more than 90% of the total yield of Gansu Province.In this paper, by dentification of major fungi isolated from Ophiocordyceps spp., in Gansu province, obtained the following results:1. Over one hundred samples of Ophiocordyceps sinensis, from Maqu, Luqu, Xiahe, Tianzhu of Gansu Province and Guinan of Qinghai Province, were isolated for many years and batches, the general isolated ratio of Hirsutella sinensis reached more than 80%. Mortierella spp., Phoma sp. , Pseudogymnoascus roses and Paecilomyces spp. etc. 14 fungi populations were also frequently isolated, but the ratios were unsteady in different batches.2. The morphological diversity of Ophiocordyceps sinensis stroma and condia of Hirsutella sinensis was researched. A few samples of Ophiocordyceps sinensis born 2-4 stromata per endosclerotium or formed dichotomous stroma, in major producing areas of Ophiocordyceps sinensis of Gansu Province. Hirsutella sinensis can produced colourless and near black condia in culture, different from original description of the species and prior report.3. Ophiocordyceps gracilis and Ophiocordyceps emeiensis were new records in Gansu Province. They were collected in Xiahe and Luqu of Gannan Tibetan Autonomous Prefecture. The ratio of Paraisaria dubia isolated from endosclerotium of Ophiocordyceps gracilis reached 100%, the ratios of Hirsutella sp. isolated from endosclerotium and stroma of Ophiocordyceps emeiensis reached 100% and 60% respectively. The ratios of Verticillium spp. from Ophiocordyceps gracilis reached 50%, the ratios of Paecilomyces spp. were high for two species of Ophiocordyceps.4. Cultural and biological characters shows, Hirsutella sinensis strain Cordy-007, Geomyces pannorum strain Geo-6 and Pseudogymnoascus roseus strain Pseu-F was psychrophilic fungi, optimum growth temperature≤20℃, the lethal temperatures of mycelium of three strains were 30℃two weeks, 35℃one week, 35℃one week , respectively.5. The results of comparative research of morphology and molecular biology, reconfirmed that Hirsutella sinensis is anamorph of Ophiocordyceps sinensis, and the anamorph of Ophiocordyceps emeiensis is Hirsutella sp..6. Submerged culture media were screened by means of orthogonal design experiments to Geomyces pannorum strain Geo-6 and Pseudogymnoascus roseus strain Pseu-F, the potential resources fungi.Test factors included sucrose, glucose, peptone, yeast extract, soybean, potato, mineral salt and Co.VB. Based on the results of tests, for strain Geo-6, the best combinations of culture medium are sucrose 20g, glucose 10g, yeast extract 5g, soybean 25g, potato 100g , Co.VB 0.2g, in 1000ml liquid medium; for strain Pseu-F, the best combinations of culture medium are sucrose 20g, glucose 10g, peptone 10g, yeast extract 5g, soybean 50g, potato 100g, in 1000ml liquid medium. Mycelia yield (dry weight) of strain Geo-6 and strain Pseu-F came up to 17.36g/L(cultured 8d) and 36.32~36.86g/L(cultured 4-5d) respectively, in optimal formula liquid medium.