Visualization of orchid mycorrhizal fungal structures with fluorescence dye using epifluorescence microscopy

The mycorrhizal association is a well-known mutual relationship between two organisms, a fungus and the root of a vascular plant. We report here the use of acridine orange for fluorescence microscopy, which is an effective method for a rapid screening of cellular details to study the complex fungal structures of orchid mycorrhizae. Spathoglottis plicata Blume, an ornamental orchid commonly cultivated in several parts of the world, was selected for this study. Its underground bulbs produce several roots that have mycorrhizal association. The plants were maintained in pots with natural inoculum of the mycorrhizal fungus Eupholorhiza repens..