Diversity of root-associated fungi of Vaccinium mandarinorum along a human disturbance gradient in subtropical forests,China

Aims Ericaceous plant species can host diverse fungi in their roots,including ericoid mycorrhizal fungi(ERMF),endophytes,pathogens and some species with unknown functions.However,how this diversity of fungi responds to different human disturbances is not well understood.Methods In this study,we examined the effects of different human disturbance on fungal diversity in hair roots of Vaccinium mandarinorum,an ericaceous plant.Fungal DNA was extracted from hair roots of V.mandarinorum and high-throughput sequencing was applied to detect the diversity of root-associated fungi along a human disturbance gradient in subtropical forests in Gutianshan National Nature Reserve(GNNR)in East China.The four forest types with different disturbance regime were:old growth forest(OGF),secondary forest with once cut(SEC I),secondary forest with twice cut(SEC II)and Cunninghamia lanceolata plantation(PLF).Important Findings The results showed that:(i)diverse fungal operational units(OTUs)were detected in hair roots of V.mandarinorum in the four types of forests,covering fungal phyla of Ascomycota,Basidiomycota,Chytridiomycota,Glomeromycota and Zygomycota;(ii)Community composition of root-associated fungi of V.mandarinorum in PLF was distinct from those in the other three forest types,and two types of secondary forests had similar fungal community composition;(iii)Different fungal families respond differently to human disturbances:fungal families with significant preference to OGF were ectomycorrhizal or saprophytic fungi while fungal families with higher relative abundance in PLF were plant pathogenic or saprophytic fungi;(iv)The first principal component(PC1)of plant community had a significant effect on composition of root-associated fungal community,while edaphic parameters showed no significant effect on fungal community composition in roots of V.mandarinorum.Our results help to better understand the responses of both ericaceous plants and their fungal partners to human disturbances and forest managements.