SPECIFICITY OF THE ASSOCIATIONS BETWEEN MICROTIS-PARVIFLORA (ORCHIDACEAE) AND ITS MYCORRHIZAL FUNGI

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