Fig. 1

Collection and isolation of DCXC and its microhabitat samples. a The sample was collected from Ya-an ethnic township, Baqing country of Nagqu Prefecture; b The samples for this study were collected in three different populations at least 50–100 m apart at 4520 m above sea level; the stars indicated the governments of Biru, Nierong, Sog and Baqing county; the triangles indicated the sampling locations in the Ya-an ethnic township, Baqing County; c habitat of natural DCXC; d-i after collection of growing DCXC (d and e). The collected samples were divided into DCXC and its growth microhabitats. Microhabitat samples included soil adhering to the surface of the membrane (f), and external mycelial cortices (membrane covered around the larva) (i). The DCXC was divided into sclerotia (g) and stroma (h)