Effects of fungal isolates on ectomycorrhizal development and growth of water-stressed northern red oak (Quercus rubra L.)seedlings in stockpiled topsoil

Abstract

Abstract Northern red oak (Quercus rubra L.) seedlings were inoculated with five isolates of Plsollthus tlnctorlus (Pers.) Coker and Couch and three isolates of Cenococcum geophilum Fr, individually and with three combinations of Plsollthus and Cenococcum, and subjected to a series of four soil drying periods In a greenhouse. Seedlings were grown in a stockpiled topsoil from a coal surface mine. When introduced individually most of the Plsollthus isolates formed significantly more ectomycorrhlzae than Cenococcum isolates on seedlings that were colonized. Ectomycorrhizal development of seedlings inoculated with mixtures of Plsollthus and Cenococcum was erratic. Only root dry weight of seedlings inoculated with one of the Plsollthus isolates was significantly increased over that of nonmycorrhizal controls. Increases In root growth over the controls were generally less for seedlings inoculated with both fungal species than for seedlings Inoculated with either fungal species.