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Manganese Accumulation in Wood Decayed by White Rot Fungi. Robert A. Blanchette, Assistant professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108; Phytopathology 74:725-730. Accepted for publication 5 March 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-725.

Black regions and flecks in wood decayed by several white rot fungi (Cerrena unicolor, Dichomitus squalens, Ganoderma applanatum, G. tsugae, Heterobasidion annosum, Ischnoderma resinosum, and Perenniporia medulla-panis) contained large concentrations of manganese. Two types of decay patterns occurred in wood degraded by these fungi: a selective delignification resulting in the removal of lignin and hemicellulose and a typical white rot causing simultaneous removal of all cell wall components. Atomic emission spectrometry and X-ray microanalyses detected manganese and determined its spatial relationship within selectively delignified wood. Black regions in eastern hemlock wood decayed by G. tsugae showed over a 100-fold increase of manganese when compared with sound wood. When black regions were compared with surrounding delignified wood and adjacent white-rotted wood, the increases of manganese were 24-fold and 51-fold, respectively. In contrast to the other decays examined, manganese deposits were found in white-rotted wood attacked by Fomes fomentarius. Micromorphological characteristics of decayed wood and manganese deposits were observed with scanning electron microscopy. Leucoberbelin blue reagent confirmed the presence of manganese oxides within the black regions.