Brown rot fungal antigens were detected by particle capture immunoassay (PCI) in southern pine 2 x 4's beyond visible or culturable hyphal growth. Further analysis of test samples revealed changes along the 2 x 4's that could be grouped into zones. Zone 1, the point of inoculation through 6 cm, showed low pH, measurable oxalic acid, high moisture, and high protein. Zone 2, through 16 cm, marked the end of visible hyphal growth, increased permeability, viable fungi isolated by culturing, and detection by microscopic examination. Zone 3, through 71 cm, revealed increased alkali solubility. Zone 4, through 84 cm, demonstrated positive PCI results (i.e. detection of fungal antigens). Further testing included mineral analysis which revealed iron accumulation. Movement of soluble fungal antigens beyond hyphal growth may account for the ability of the PCI to detect the presence of brown-rot fungi at zero percent wood weight loss.

Download document (411 kb)
free for the members of IRG. Available if purchased.

Purchase this document