During shipment and storage, lumber is susceptible to sapstain, a wood discoloration caused by fungi. Currently kiln drying and chemical applications are used to control sapstain. However, the chemicals used to protect wood have a broad range of action, and so can affect other organisms. In addition, in Canada most of these chemicals are under temporary registration. Thus there is a need to develop alternative strategies for wood protection. Instead of inhibiting fungal growth one approach would be to block the production of the fungal pigment responsible for discoloration. Very little is known about pigmentation in sapstaining fungi. However, in Ophiostoma piliferum, Ophiostoma piceae and Alternaria alternata, the discoloration is due to melanin production. While fungal melanin can be synthesized by several different metabolic pathways, Alternaria alternata produces melanin via the dihydroxynapthalene (DHN) pathway. To determine whether several common sapstaining fungi also utilize this pathway, a gene from Alternaria alternata's DHN pathway was radiolabeled and used as heterologous probe to screen Southern blots from six species of staining fungi. The results suggest that most of these fungi have homologous (similar) genes for the enzymes of the DHN pathway. The genes from Ophiostoma piceae will be further characterized, to facilitate more directed development of anti stain strategies.

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