Study On Myxomycetes Diversity In Qilian Mountain National Nature Reserve,Gansu Province,China

Myxomycetes is a special kind of organism.Its life history includes both spore-producing stage with fungal characteristics and protoplasmic mass stage with feeding mode of protozoa.Slime molds are widely distributed in nearly all parts of the world,and the common habitats are mainly under dark and moist forests,and the main substrate types are dead wood,dead branches,dead leaves,etc.,among which dead wood is the best substrate type for the occurrence of slime molds,but it can also be found in extreme climate conditions,such as Alpine snow melting zone,desert,swamp,etc.Qilian Mountain National Nature Reserve is located at the northern foot of qilian mountain at the intersection of qinghai-tibet,meng-xin and loess plateaus in Gansu province.From July 2018 to August 2019,we investigated the myxomycetes diversity of this area,providing important data for the protection of myxomycetes resources.More than 820 specimens of slime molds were collected from the Qilian Mountain National Nature Reserve in Gansu province,and 71 species of slime molds were identified,belonging to 4 orders,5 families and 22 genera.Including 1 family,1 genus,1 species of Ceratiomyxales,2 family,5 genus and 7 species of Liceales,1 family,3 genus,15 species of Trichiales,2 family,9 genus,39 species of Physarales,1 family,4 genus,9 species of Stemonitales,including 30 new record species and 14 new places of distribution in Gansu Province.The dominant families are Trichiaceae,Physaraceae,Didymiaceae.The dominant genera are Arcyria,Trichia,Physarum and Didymium.There were 18 species of slime molds that could be found in four different elevations,and 27 species of slime molds that could be found in two different forest types.Combining the data of different elevations and forest types,according to the analysis of the species distribution,9 species including Ceratiomyxa fruticulosa were found to be the widely distributed in the natural reserve,the number of total species(58 species)and endemic species(38 species)was higher in coniferous forests than in broad-leaved forests(33 species and 13 species),and the altitude had no significant effect on the diversity of myxomycetes.The principal component analysis showed that the diversity of myxomycetes was most abundant on dead woods,and the species composition of myxomycetes on woody substrates and herbal substrates were significantly different.This study suggests that the type of vegetation and substrate in the mountain forests is the important factors affecting the species composition and diversity of myxomycetes in Qilian Mountain Natural Reserve of Gansu Province.Phylogenetic tree was constructed by SSU rRNA of L.epidendrum from three different regions.The L.epidendrum specimen collected in different sites showed clear separation.The L.epidendrum specimen from Qilian mountain,daxingan mountains and Changbai mountain also showed clear separation.