Interaction between AMF and phosphate solubilizing fungi. Effect on AMF hyphal growth and alkaline phosphatase activity

J. M. SCERVINO; R. PEÑA; A. GODEAS; I. DELLA MONICA

Belo Horizonte, Brasil

Congreso; 6th international conference on mycorrhiza; 2009

ICOM

Phosphorous is one of the main nutrients. It occurs mainly as inorganic phosphate derivatives, unvailable to plants. Pi is converted into plant available forms by some saprophytic fungi. AMF produce alkaline phosphatase enzimes that solibilize P sources and improve nutrient absortion by incresing the absortive surface area of the roots. Exudates of some phosphate solubilizer are considered germination modulators since they either stimulate or inhibit hyphal growth, depending on their concentrations. In this work, we tested the effect of T. flavus exudates on Gigaspora rosea in vitro by studying the interation between P solubilizer and AMF. The 1-3% and 0.5-1% concentrations increased the hyphal length and the number of braches respectively, suggesting the presence of substances that improve the growth and ramification of the AMF mycelia. We also evaluated the effect of T. flavus on the hyphal AP of G. intraradices in green house experiments. The AP activity percentage was higher in the presence of T. flavus with P amendaments. The results show that presence of Pi produce changes in T. flavus exudates that possitively influence the activity of AP of G. intraradices.