EARLY DETECTION OF BROWN-ROT DECAY IN SOUTHERN YELLOW PINE USING IMMUNODIAGNOSTIC PROCEDURES

Immunodiagnostic procedures have been used to detect incipient decay of southern yellow pine by six common brown-rot fungi. Rabbit polyclonal antibodies were raised to liquid culture fractions of the six fungi. The antibodies, after preadsorption to sawdust, were tested in particle agglutination assays, immuno-dot blot, and enzyme-linked immunosorbent assay (ELISA) for their ability to detect the decay organisms when they were grown in southern yellow pine. Results were correlated to wood-block weight loss. Each method specifically detected five of the six test organisms at very low wood-block weight loss. Agglutination assays were the least effective and lacked the sensitivity of the other assays, even though the latex particles were more sensitive and reproducible than charcoal particles. Cross-reactivity was noted only for one of the control organisms and only in the charcoal agglutination assay. Both dot blot and ELISA were sensitive test methods, but ELISA had the advantage of quantification. We feel that two of these assays, latex for presumptive results and ELISA for definitive results, could effectively detect incipient decay of common brown-rot fungi.