Colonization of arbuscular mycorrhizal fungi and dark septate endophytes in roots of desert Salix psammophila

Aims Salix psammophila is an excellent shrub for afforestation and sand dune fixation and is mainly distributes in the arid zones in North China. The objective of this study was to determine the colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE), and the relationships among AMF, DSE and soil factors in the rhizosphere of S. psammophila, in order to provide information guiding the recovery of desert vegetation and ecological reconstruction. Methods Soil and root samples were collected from different soil layers (0–10, 10–20, 20–30, 30–40 and 40–50 cm) in the rhizosphere of S. psammophila in June, August and October 2013 at Yuan Shangdu in Nei Mongol. The colonization and distribution of AMF and DSE were assessed, and the relationships among AMF, DSE and soil factors were determined and tested by variance analysis, correlation analysis and principal component analysis. Important findings The roots of S. psammophila could be highly infected by AMF and DSE, and the average colonization of AMF and DSE were 77% and 84%, respectively. Sampling time and soil depth significantly influenced the AMF and DSE colonization. The maximum colonization of AMF was found in the 0–20 cm soil layer and DSE in the 0–10 cm soil layer, respectively, and the effects of sampling time on colonization were in the order of October > August > June. Two-way ANOVA showed that sampling time and soil layer had significant interactive effects on the colonization and distribution of AMF and DSE as well as soil factors. Principal component analysis showed that soil humidity, pH value, alkaline phosphatase and easily extractable glomalin were the main factors of AMF and DSE colonization in desert environments.