Deep Sequencing, Nested Pcr, And Denaturing Gradient Gel Electrophoresis Reveal A Wider Distribution Of Chinese Caterpillar Mushroom, Ophiocordyceps Sinensis (Ascomycetes), In Native Soil Types

Ophiocordyceps sinensis appears as stroma emerging from underground sclerotium enclosed by the skeleton of Thitarodes moth larvae. However, the actual distribution of the fungus in soil still remains unclarified. In this study, 40 soil samples were used for detection of O. sinensis to confirm its distribution in native habitats using denaturing gradient gel electrophoresis, nested internal transcribed spacer (ITS) PCR, and 454 pyrosequencing methods. The soil samples included six types: Os, where both stromata and host moth larvae were found; NL, representing no signs of stromata, but where moth larvae were found; NOs, where neither stroma nor moth larvae were found; BS, with bare soil without the presence of stroma of O. sinensis or moth larvae; AF, from soil surrounding the stroma; and MP, soil particles firmly wrapping the sclerotium of O. sinensis. Of 40 samples tested, 36 showed positive detection of O. sinensis by at least one of the three detection methods, with positive detection in all six sample types at all five sites. The results showed that traces of O. sinensis can be detected in locations with no macroscopically visible evidence of the fungus or its host and at least 100 m away from such locations.