Mycorrhiza in the Gramineae: III. Glomus fasciculatus as the endophyte of pioneer grasses in a maritime sand dune

Abstract

In a sand-dune system at Tentsmuir Point, Fifeshire, Scotland, Glomus fasciculatus was the only endophyte present on roots of pioneer colonizing grasses. This fungus formed sporocarps and spore aggregates in the soil and in association with organic fragments, particularly root tissues. Amounts of infection and external mycelium varied with vegetation zone and season, but both became greater with dune stabilization and infection increased during summer and autumn. Growth of Ammophila arenaria and Agropyron junceiforme in unsterile foreshore sand was improved when mycorrhizal with G. fasciculatus and G. macrocarpus var. geosporus. Experiments in dune sands, with maize as a test plant, gave better growth with both these endophytes than with either alone, but indicated the complexity of interaction between host, endophyte and edaphic factors. The possible significance of mycorrhizas in nutrientpoor and unstable habitats is discussed.