The effect of vesicular–arbuscular (VA) mycorrhizal fungi on vitamin C content of tomato in the presence of lead (Pb) and different levels of phosphorus (P)

In a greenhouse experiment, tomato (lycopersicum esculentum L. cv. Soltan) seedlings germinated were inoculated with Glomus versiform (G1) and Glomus etunicatum (G2) in a pasteurized low phosphorus (P) and lead (Pb); the uninoculated one was the control (G0). Three Pb levels (5, 10, 50 mg/kg; Pb1, Pb2 and Pb3, respectively) as PbSO4, and three P levels (5, 20 and 40 mg/kg; P1, P2 and P3 respectively) as KH2PO4 were applied to the soil during transplanting. Based on the results obtained, vitamin C content of fruits was affected by Pb and P levels in both mycorrhizal and non-mycorrhizal plants. It was observed that vitamin C content of fruits was enhanced significantly with increased P level, but decreased significantly in Pb level; and it was significantly higher in mycorrhizal plants than in non-mycorrhizal plants at the same level of P and lower at the same level of Pb. Percentage of root colonization was negatively affected by Pb level of soil and positively affected by P levels. Percentage of root colonization was significantly higher in mycorrhizal plants than in non- mycorrhizal plants at the same level of P and lower at the same level of Pb. However, there was no significant difference between G. versiform and G. etunicatum.

Keywords:

Lead (Pb) , phosphorus (P) , tomato , vesicular–arbuscular (VA) mycorrhiza , vitamin C