Influence of organic matter on the growth of the ectomycorrhizal fungi Pisolithus tinctorius and Thelephora terrestris

Abstract

The effects of water extracts of sewage sludge, filter cake, manure and pine needle mulch on the mycelial growth of Pisolithus tinctorius and Thelephora terrestris were evaluated at the concentrations of 1, 10, 100 and 1.000 ppm and 1, 2, 3, 4, 5, 10, 15 and 20% (v/v) in MMN-agar (Melin, Norkrans medium, modified by Marx). There was no significant effect of the organic matters tested at concentrations below 1%. At concentrations above 1.000 ppm, pine needle mulch decreased the growth of both fungi tested. Sewage sludge reduced the growth of P. tinctorius at concentrations above 1.000 ppm. Growth of T. terrestris was also reduced by sewage sludge, but at concentrations higher than 3%. Filter cake had no effect on P. tinctorius, whereas manure reduced growth of this fungus at 20% only. Filter cake and manure decreased growth of T. terrestris at concentrations higher than 4%.