常見樹木腐朽菌的鑑定及防治之研究

Abstract

城市中之樹木常可見易受到木材腐朽菌(wood decay fungi)的感染，造成樹木木材腐化、空洞或斷裂，嚴重者更會導致全株倒伏，影響公共安全。本研究主要於台灣北部地區調查腐朽樹木及分離木材腐朽菌，共選出六種木材腐朽菌進行鑑定。鑑定結果得知，六菌株分別是Ganoderma weberianum、Ganoderma gibbosum、Phlebiopsis ravenelii、Leiotrametes lactinea、Hydnochaete japonicaz及一不確定者。測試此六個腐朽菌株分泌分解酵素之能力，結果顯示，六個木材腐朽菌株皆有分泌纖維素分解酵素及木質素分解酵素之能力，證明六菌株都為白腐菌。而其中以DW04菌株(Phlebiopsis ravenelii)及OG12菌株(Ganoderma weberianum)所分泌的分解纖維酵素之活性最強；而分泌之漆化酵素之能力以OG12菌株(Ganoderma weberianum)和OG03菌株(Ganoderma gibbosum)最高。為迅速了解六菌株之腐朽速度及能力，對其進行簡易木片腐朽測試，使用2種不同尺寸之松木片，發現以DW04菌株(Phlebiopsis ravenelii)之腐朽能力最強，DW06菌株(Hydnochaete japonica)最弱。利用瓊脂稀釋平板法法，將14種殺菌劑添加於馬鈴薯葡萄糖瓊脂培養基(potato dextrose agar, PDA)，測定不同濃度之殺菌劑對腐朽菌的抑制效果。發現菲克利、待克利、普克利及得克利都有良好之抑制效果。進一步以木片進行殺菌劑對菌株之抑制能力試驗中，結果顯示待克利對韋伯靈芝有較佳之抑制效果，菲克利對南方靈芝有良好之抑制能力。而在樹木腐朽菌藥劑防治劑型之試驗中，以三年生之小葉欖仁和阿勃勒苗木作為試驗材料，在只接菌之對照組中，分離率皆為100%，而在阿勃勒苗木之處理，待普克利與AB膠混合劑之抑制木材腐朽菌之效果最佳；在小葉欖仁苗木之處理，待普克利與水泥漆混合劑和待普克利與凡士林混合劑對於抑制木材腐朽菌之效果最好。

Urban trees were frequently infected by wood decay fungi and caused wood rot, wound and cracking. Thus make them easily to fall down after strong wind and threaten the public safety. This study is aimed to survey the rotten trees in northern Taiwan, collect the wood decay samples, and isolate the wood decay fungi from infected trees. A total of six of wood decay fungi were identified in this study. They are Ganoderma weberianum, Ganoderma gibbosum, Phlebiopsis ravenelii, Leiotrametes lactinea, Hydnochaete japonicaz and one uncertain isolate. They were tested for their capability for producing the decomposition enzymes for cellulose and lignin. Results showed that all six fungi can produce cellulase and laccase enzyme that belong to the lignin decomposition enzyme. Among the six fungi, DW04 (Phlebiopsis ravenelii) and OG12 (Ganoderma weberianum ) showed the highest yield of cellulose, while OG12 (Ganoderma weberianum ) and OG03 (Ganoderma gibbosum ) produce the highest level of laccase enzyme. To test the wood-decaying capability, we develop a wood disc method, using 2 size of pine wood disc. Results showed that among them the DW04 (Phlebiopsis ravenelii) showed the fastest decaying speed, while the DW06 (Hydnochaete japonicaz ) showed the least capability. The dilution plate method was used to screen 14 fungicides for their inhibiting potential against the six wood decay fungi at different concentrations on PDA. Results showed that Hexaconazole, Difenoconazole, Propiconazole and Tebuconazole have higher inhibitory effect than the others. The further test on wood discs treated with fungicide showed that Difenoconazole has better inhibiting effect on Ganoderma weberianum, while Hexaconazole has a good effect on Ganoderma gibbosum. In the test of tree wound protecting agents for trees, two species (Terminalia mantalyi and Cassia fistula)of tree with age of 3 years were selected and tested. The wound were brushed with wood decay fungi, then pasted with glue materials added with Difenoconazole + Propiconazole. The reisolation rate of wood decay fungi from inoculated wounds were higher than those pasted with the Difenoconazole + Propiconazole agent. In the Cassia fistula experiment, the Difenoconazole + Propiconazole and AB glue mixture showed the best protection result. While in the Terminalia mantalyi experiment, the Difenoconazole + Propiconazole and Cement or Vaseline mixture showed the better results.