6.9
SLIME MOULDS FOUND FROM EDIBLE MUSHROOM CULTIVATION SITES

CH CHUNG1, CH LIU2 and SS TZEAN1

1Department of Plant Pathology and Entomology, and 2Department of Botany, National Taiwan University, Taipei, Taiwan, ROC

Background and objectives
In eastern Asia, where the cultivation of edible mushrooms is a common component in agriculture, reports on the occurrence of slime molds on logs for mushroom cultivation are not rare. Plasmodia feed on fruiting bodies of cultivated mushrooms and cause spoilage or inhibit the fruiting process. When Liu et al. [1] studied diseases of edible mushrooms of China, they noted that there is no ideal control method available for slime mould disease. This does not imply that slime moulds are not able to cause serious problems. Slime mould disease is probably more common than expected, since mushroom growers may fail to recognize slime moulds as pathogens. In addition, reports on mushroom diseases often failed to identify them. We are also unaware of any attempt at any scale to estimate the degree of damage caused by slime moulds. In order to facilitate the understanding of the slime mould-edible mushroom association, we summarize our preliminary observations on the biodiversity of slime moulds associated with edible mushroom cultivation.

Materials and methods
Collections of slime moulds in the Mycology Laboratory, Department of Botany, National Taiwan University were screened for specimens found in mushroom cultivation sites. In addition, one of us (Chung) has visited several mushroom cultivation sites in northern Taiwan during 1995-97 to make supplementary observations. The identification of slime moulds follows Martin and Alexopoulos [2].

Results and conclusions
A total of 29 species and four varieties of slime moulds have been recorded from various edible mushroom cultivation sites of Taiwan. Among them, 14 species and two varieties were not previously reported to be associated with cultivated mushrooms. Fuligo septica var. flava Persoon is reported as new to Taiwan. Analysis of the component of slime moulds in each order by this study indicated that Stemonitales are predominant, followed by the Trichiales. Taxa with minute sporocarps, e.g. Licea and species of Echinosteliales, tend to be overlooked in the dim light of mushroom cultivation sites. Studies using moist-chamber culture techniques are needed in the future.

The current remedies for slime mould disease in mushroom cultivation include reduction of water supply, and removal of plasmodia and young sporocarps. The application of table salt is sufficient to eliminate plasmodia, but this requires enormous labour. The possibility of chemical and biological control of slime mould disease requires further investigation.

References
1. Liu B, Liu YH, Fan L et al., 1991. Diseases of Edible Fungi and their Control. Shanxi Science and Education Press (in Chinese).
2. Martin GW, Alexopoulos CJ, 1969. The Myxomycetes. University of Iowa Press, Iowa.