Enhanced rooting of <i>Picea mariana</i> cuttings by ectomycorrhizal fungi

Abstract

Cuttings of Picea mariana (Mill.) B.S.P. and Larix decidua Mill, were rooted in a peat moss – vermiculite substrate inoculated with vegetative mycelium of two ectomycorrhizal fungi. The fungal influence on rooting was compared with auxin-treated cuttings. The symbionts stimulated rhizogenesis of P. mariana, resulting in significantly increased rooting percentage, number of roots per cutting, and average root length as compared with controls. The best rooting percentage and the highest number of roots formed per cutting was reached under the hormonal treatment. No stimulating effect by ectomycorrhizal fungi was observed on L. decidua cuttings. With L. decidua, no significant differences in rooting percentage between the four treatments were obtained. The use of indolebutyric acid significantly increased the number of roots per cutting and decreased mean root length.