LIGHT AND ELECTRON-MICROSCOPY OF THE HOST-FUNGUS INTERACTION IN THE ACHLOROPHYLLOUS GAMETOPHYTE OF BOTRYCHIUM-LUNARIA

The host-fungus interaction between the achlorophyllous gametophyte of Botrychium lunaria and its fungal endophyte was studied by means of l ight and electron microscopy. Aseptate hyphae with a multilayered cell wall formed intracellular coils. The interface consisted of a thick l ayer of fibrillar matrix material, an electron-translucent zone, and t he host plasmalemma. Several Vesicles that show different stages of de velopment and degeneration occurred within one host cell. Degenerating vesicles were encased by large amounts of an electron-translucent mat erial. Arbuscules were not observed. The fungus did not infect the you ng sporophyte but degenerated within intact gametophyte cells.