Rhizophagus clarus e fósforo em Crotalaria juncea em solo com altos teores de cobre

Abstract

Arbuscular Mycorrhizal Fungi (AMF) can increase the tolerance of plants to heavy metals, as well as their ability to enhance the acquisition of phosphorus (P). The aim of this study was to evaluate how the inoculation with AMF and P application can remedy the effects of high levels of copper (Cu) in the soil on Crotalaria juncea. The effects of AMF and P on the growth of plants, the enzymatic activity of acid phosphatase (APases) in plant and soil as well as the presence of glomalina. The experiment was conducted in a greenhouse in a 3 x 2 factorial arrangement (natural content of P, 40 and 100 mg kg-1 of P, with and without inoculation Rhizophagus clarus) with three replications in a soil with high levels of Cu (60 mg kg -1). Besides the treatments of P and AMF in soil with high levels of Cu, were evaluated two additional treatments in soil with natural levels of Cu (0.55 mg kg-1) containing 40 mg kg-1 of P, with and without AMF inoculation. The results showed that the combination of P and AMF (Rhizophagus clarus) may be an interesting strategy for the reduction of Cu phytotoxicity in Crotalaria juncea, as provided increments in dry matter production of plants and a decrease in the activity of acidic enzyme APases in soil and plants. Furthermore, it was showed that Glomalin produced by AMF can decrease Cu availability to the plants with phytoprotector consequent effect.