Specifically primed polymerase chain reaction (PCR) analysis was carried out for the detection and identification of decay fungi. Internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (rDNA) of Serpula lacrymans and Coniophora puteana were amplified. DNA templates was extracted from the mixture of freeze-dried mycelia and coniferous heartwood powders (Tsuga het-erophylla, Picea jezoensis, Abies sachalinensis, Larix leptolepis), and from the pieces of experi-mentally decayed wood (Abies sachalinensis). In this study, the mycelium and wood specimen from the damaged sill plate were also analyzed. Except for the mixture of Larix leptolepis, target regions were successfully amplified by PCR. Furthermore, PCR allowed detection of Coniophora puteana in the damaged sill plate. The results suggest that PCR analysis contributes to the accu-rate detection and identification of the fungi in timber and provides the useful information about the biological degradation of the wood.

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LIFETIME Wood Treatment made up of naturally occurring plant and mineral substances was investigated for its effectiveness against fungi by an accelerated laboratory decay test. Japanese cedar blocks treated with it acquired high durability against the white-rot fungus, Trametes versicolor. They also showed weak resistance against the brown-rot fungus, Fomitopsis palustris. How-ever, in the latter case, about 30% of mass loss was observed after decay treatment for 12 weeks. In the Japanese Industrial Standard K 1571, 3% of mass loss is the maximum percentage allowed for wood preservatives to pass the decay test. LIFETIME can improve wood durability against fungi but its effectiveness is lower than that of wood preservatives certified by the standard such as JIS K 1571.

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