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CHARACTERISTICS OF FUNGI

Fungi are by far the most important group of plant pathogens. There are over 200,000 known species of fungi and over 8,000 species can cause plant diseases. Note that the majority of fungi are NOT plant pathogens. These fungi, which primarily survive on non-living organic material, are called SAPROPHYTES.

Many fungi (including some plant pathogens) can be seen with the naked eye. Typically however, you are not seeing the major "body" of the fungi, but simply a reproductive structure (e.g., a mushroom).

The non-reproductive "body" of most fungi (called the vegetative phase) is composed of a mass of a fungal threads called HYPHAE (singular = HYPHA). This mass of hyphae is called a MYCELIUM (plural = MYCELIA). While an individual hypha is microscopic, mycelia are often visible with the naked eye.

Fungi reproduce by production of spores that can be a variety of shapes and colors. They are produced in a wide variety of reproductive structures that, in general, are referred to as FRUITING BODIES. Most fungal plant pathogens (except for a few that produce mushrooms) form fruiting bodies that are microscopic in size.

Because characteristics of fungal spores and fruiting bodies are what help us identify fungi, accurately diagnosing a fungal disease without a microscope can be difficult, if not impossible.