Root AMF colonization
AMF abundance in roots was determined as root length colonization in percent. Roots were cut into 1-1.5 cm fragments and 10% KOH was used to clear the roots. Then, roots were washed with distilled water and acidified with 1% HCl and placed in a 2% blue ink solution for staining before clearing them with lactoglycerol (1:1:1) (Phillips & Hayman 1970; Vierheilig, Coughlan, Wyss & Piche 1998). Root fragments were mounted on glass slides and root length colonization by AMF was quantified with the intersection method (McGonigle, Miller, Evans, Fairchild & Swan 1990). All scanned and un-scanned roots were pooled together and dried at 70 °C for 48 h to determine root biomass on a dry weight basis.