Specificity of the Associations Between Microtis parviflora (Orchidaceae) and Its Mycorrhizal Fungi

Abstract

The specificity between Microtis parviflora R.Br. and its mycorrhizal associates was examined in situ and in vitro. Two fungi, Epulorhiza repens (Bernard) Moore and Epulorhiza sp. Moore (synonym Rhizoctonia globularis), were isolated from the roots and protocorms of the orchid from the field. In the laboratory, these fungi and three others that form mycorrhizae with other orchids and two others that are saprophytes, initiated mycorrhizae with M. parviflora. Two pathogenic isolates of Rhizoctonia solani Kuehn killed the germinating seeds. The addition of sucrose to the germination media increased growth and rate of development of seedlings.