Study On Formation Mechanism Of Spalted Wood

Spalting is the coloration of wood caused by fungi colonization, the intricate zone lines and stains perform attractive figures. Spalted wood are popular material of crafts in Europe andAmerica, but very little research and utilization in domestic. To cultivate spalted wood, in this study, spalted wood was collected and investigated in the wild and fungi were isolated and cultivated, followed by inoculating the cultivated fungi on the normal wood of Alnus nepalensis. Several spalted isolations were selected for experiments of moisture influence, copper sulfate stimulation and double fungi inoculation in cultivating spalted wood to explore the formation mechanism of spalted wood.Abundant light-colored hard wood are prone to form zone lines, the common species i.e. Acer mono, Albizzia julibrissin, Michelia alba, Ficus virens, Cyclocarya paliurus, Phoebe neurantha, Populus davidiana, and so on.36 isolations 19 fungal species were screened from collected spalted wood samples, including 9 Diaporthe spp.(Phomopsis spp.), 5 Xylarias spp., Beltrania sp., Daldinia childiae and so on, but not all fungi in the same genus formed spalting, almost forming black zone lines and black or greenyellow pigments, little decay was found during the early period.This research indicates that spalting could be stimulated by controlling moisture content of the substrate, and optimal conditions are specific to fungal species, Diaporthe sp.J9-1 was significantly stimulated at 52%~65% moisture content, while Diaporthe sp.ZXH18-1 was significantly stimulated at 39%~65% externally and at 52%~65% internally and Diaporthe sp.ZXH63-4 was significantly stimulated at 79%~99% externally and at 52%~65% internally. Moisture content did not significantly affect wood mass loss.The accident loss of wood moisture content in the early stages of the experiment result in failure of estimate infuluence by copper sulfate, but ZXH63-4 form significantly more spalting than ZXH18-1. Double strians and single strians inoculation by 4 isolations(ZXH63-4、Phomopsis sp.ZXH28-2、Beltrania sp. ZXH62-2 and Chlorociboria aeruginascens) showed that double strians inoculation has good effects of forming more types and more quantity spalting.Many species of Diaporthe and Xylaria were reported as plant endophytic fungi, the mechanism of forming zone lines by Diaporthe and Xylaria maybe: after living tree die, endophytic fungi inside could form zone lines to defend environment stress, or to keep moisture content of colonization area, or to form stroma or sporocarp for propagation.