COLONIZATION PATTERNS AND TOPOCHEMICAL ASPECTS OF SAP STREAK CAUSED BY STEREUM-SANGUINOLENTUM IN NORWAY SPRUCE

Fresh sapwood blocks of Norway spruce (Picea abler) were exposed to 12 - and 60-day attack by Stereum sanguinolentum in pure culture and were examined with respect to structural, topochemical and colour alterati ons. Final stages of degradation by S. sanguinolentum were studied on naturally decayed spruce wood after 1 year of fungal growth. The devel opment of discoloration in the main anatomical directions of wood was assessed. Furthermore, microspectrophotometrical studies on the decomp osition of cell wall polyphenols were performed. Initial signs of sap streak appeared already 8 days after fungal infection. Within the thre e-dimensional decay pattern, mycelial aggregations associated with the ray tissue proved to be the major cause of discoloration. UV extincti on measurements taken at 280 nm of different parts of cell wall transv erse sections revealed a specific pattern of lignin distribution and i ts derivatives during fungal degradation.