Nutrient Consumption and Pigmentation of Deep and Surface Colonizing Sapstaining Fungi in Pinus contorta

Abstract

Summary In this paper, we examined the ability of deep and surface staining fungi to utilize wood tissue nutrients. Fungal isolates were inoculated onto fresh billets and γ-sterilised sawnwood, both from Pinus contorta, and also onto defined nutrient media. The wood samples were assessed for host viability, fungal growth and nutrient status. The results indicated that the most aggressive sapstain species on fresh logs was Ceratocystis coerulescens, followed consecutively by Leptographium spp., Ophiostoma minus, O. piliferum, O. piceae, O. setosum, O. pluriannulatum and Aureobasidium pullulans. HPLC analysis of soluble sugars in fungal-infected wood indicated that mannose was the most depleted sugar, followed by glucose. Lipid analysis of infected wood indicated that Leptographium spp. and C. coerulescens greatly reduced the triglyceride fraction and that there was a wide spectrum of consumption of triglyceridederived fatty acids between the fungi. On defined media, the carbon source mannose led to the darkest pigmentation for all tested fungi. For C. coerulescens, the order of pigmentation intensity for the remaining tested carbon sources was reversed when compared to the other fungal species.