About 1.5–2.0 g (fresh weight) fine roots were used for staining and assessment of AMF colonization. Roots were stained with trypan blue (0.5 g trypan blue in a mixture of 876 ml lactic acid solution (Sigma–Aldrich, Milwaukee, WI, USA), 64 ml glycerol, and 60 ml H2O) after clearing the roots in 10% KOH (Phillips and Hayman, 1970)