天然耐腐木材的抗腐力及其在腐朽过程中化学成分的变化

DECAY RESISTANCE OF NATURAL DURABLE SPECIES AND THE CHANGES IN AMOUNTS OF MAJOR COMPONENTS DURING DECAY OF WOOD BY CORIOLUS VERSICOLOR AND GLOEOPHYLLUM TRABEUM

在实验室中用土壤木块法测定了杉木、楠木、檫木、白栎、楸木等心材对彩绒革盖菌(白腐菌)和密粘褶菌(褐腐菌)的天然耐腐力,并分析了样品在腐巧过程中的主要化学成分变化。试验结果表明,上述心材对彩绒革盖菌和密粘褶菌具有很大的杭腐力,而作为对照样品的杨木却很不耐腐。这个事实反映了在这些树种的心材中含有有效的抗菌成分。彩绒革盖菌几乎以相同的相对速度分解综纤维素和木质素,木材在1％NaOH溶液中的溶解度逐渐减少。密粘褶菌主要分解木材中的多聚糖,它只引起木质素含量的少量损失。木材在褐腐前期,在1％NaOH溶液中的溶解度明显增加,直到后期,由于部分降解的高聚糖碎片被褐腐菌消化,致使木材在1％NaOH溶液中的溶解度迅速下降。

Natural decay resistance of the heartwood of Cunninghamia lanceolata, Phoebe sheareri, Sassafras tzumu, Quercus fabri, and Catalpa bungei was determined by the soil-block method with Coriolus versicolor (white rotter) and Gloeophyllum trabeurn (brown rotter) in the laboratory. The changes in amounts of major components during decay of samples were analysed. The results showed that decay resistance of the heartwoods was very resistant or resistant to both C. versicolor and G. trabeum, but Populus deltoides as control sample was very susceptive to these two fungi. This reflects that these heartwood contain active antifungal substance. C. versicolor decomposes holocellulose and lignin at approximately the same relative rates, and the solubility of wood in 1％ NaOH solution drops progressively. G. trabeum mainly degradates the polysaccharides in wood and causes only a small loss in lignin, and the solubility of wood in 1％ NaOH solution increases substantially on attack by G. trabeum in early stages of brown rot. In later stages, the partially degraded carbohydrate fragments are utilized by the brown rot, so the solubility of wood in 1％ NaOH solution quickly declined drop by drop.