Percentages of mycorrhizal seedlings (A) and mycorrhizal colonization index (B) on P. halepensis inoculated with three ectomycorrhizal fungi under different N fertilization levels (low-LN: 35 mg/plant, medium-MN: 60 mg/plant, high-HN: 120 mg/plant). For each inoculation treatment, different letters indicate significant differences (Contingency tables for percentage of mycorrhizal seedlings, Duncan’s test, p ≤ 0.05 for mycorrhizal colonization).