Preliminary characterization of fungal endophytes from Nephrolepis cordifolia (L.) C. Presl and their role in the fern tolerance to inorganic pollutants.

Nephrolepis cordifolia is a fern worldwide diffused as an ornamental plant, but its biological and ecophysiological characteristics have so far been poorly studied. On the basis of a) antimicrobial substances production, b) ability to accumulate heavy metals, and c) tolerance to some rare earth elements, N. cordifoliahad been proposed as a possible candidate for phytoremediation in polluted environments. Trichoderma harzianum Rifai acts as an endophyte in tubers and roots of N. cordifolia populations grown in Bari, Taranto, Marina di Leporano (TA), Montalbano Jonico (MT), and Portici (NA). T. harzianum strain Th1, isolated from N. cordifoliapopulations grown in Bari, tollerate NaAsO2, Ce(NO3)3, and Pb(NO3)2 at concentrations up to 1 mM. The strain was completely inhibited at 10 mM concentration. A possible role of the fungal endophytes in the tolerance of N. cordifoliato tested metals is hypothesized.