Fungal coil formation ofRhizoctonia repens in seedlings ofGaleola septentrionalis (orchidaceae)

Protocorms or protocorms with roots of an achlorophyllous orchidGaleola septentrionalis were inoculated with isolates ofRhizoctonia repens, R. solani, andRhizoctonia spp. The seedlings were infected with eight of twelve isolates ofR. repens. Fungal coils were formed in the cells, which was suggestive of a symbiotic association. The other isolates caused soft rot or no infection to the protocorms or the protocorms with a root. Contribution No. 97, Laboratories of Plant Pathology and Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Tsukuba, Ibaraki 305, Japan.