ARBUSCULAR MYCORRHIZAL MORPHOLOGY IN SPOROPHYTE OF PSILOTUM NUDUM

Abstract

The mycorrhizal structures of the sporophyte of Psilotum nudum were studied by light microscopy. Further, the nature of the fungal associate was characterized through trap-culture technique. The fungal entry into the rhizome was mainly through the rhizoids with occasional direct entry through the epidermis. The fungal colonization resembling the Paristype of mycorrhiza was restricted to the cortex with the rhizome tip and the stele free of any colonization. The transversing hyphae formed coils in the host cells with intracellular vesicles, but arbuscules were absent. Single hyphae arising from the coils penetrated the neighbouring cells with a hyphal constriction at the host cell wall region. Intact and collapsed hyphal coils were found in different cells and no recolonization of the host cells was observed. Arbuscular mycorrhizal fungal spores belonging to Acaulospora scrobiculata, Glomus aggregatum and Glomus geosporum were isolated from the trap cultures and also from the soil in which P. nudum occurred