3. Results
3.1. Root colonization
At the end of the experiment, the AM root colonization was significantly affected by nutrient solution (S; p < 0.05), mycorrhi-
zal treatment (M; p < 0.001), and S × M (p < 0.001) interaction. No
AM-fungi colonization was observed in roots of noninoculated
plants while in the +AM treatments (Fig. 1), the percentage of AM infection varied significantly among plants grown under dif- ferent nutrient-solution pH and aluminium concentration. Among nutrient solution treatments, the percentage root colonization was higher in the control treatment (pH 6.0) followed by pH 3.5, and pH
3.5 + Al treatments (Fig. 1).