Ectomycorrhizal fungal community in alkaline-saline soil in northeastern China

Alkaline-saline soil is widespread in arid and semiarid regions of the world and causes severe environmental and agricultural problems. To advance our understanding of the adaptation of ectomycorrhizal fungi (EMF) to alkaline-saline soil, we investigated EMF communities on Mongolian willow (Salix linearistipularis) growing in alkaline-saline soil (up to pH 9.2) in northeastern China. In total, 75 root samples were collected from 25 willow individuals over 4.7 ha. To identify fungal species in ectomycorrhizal root tips, we used terminal restriction fragment length polymorphism and sequencing analyses of the internal transcribed spacer region of ribosomal DNA. We detected 11 EMF species, including species of Inocybe, Hebeloma, and Tomentella of the Basidiomycota and three Ascomycota species. The EMF richness of the study site was estimated to be 15-17 using major estimators. The most abundant species was Geopora sp. 1, while no Geopora-dominated EMF communities have been reported so far. Phylogenetic analysis showed that the phylogroup including Geopora sp. 1 has been found mostly in alkaline soil habitats, indicating its adaptation to high soil pH. Because EMF are indispensable for host plant growth, the EMF species detected in this study may be useful for restoration of alkaline-saline areas.