葡萄座腔菌屬病原菌為引起台灣木棉潰瘍病與苦楝流膠病之可能病原

The probable pathogens cause canker disease of Bombax ceiba and gummosis of Melia azedarach belong to Botryosphaeria spp.

樹木潰瘍病主要由真菌侵染所致，在引起病害的多種病原真菌中，葡萄座腔菌屬（Botryosphaeria spp.）是重要的一屬。該屬真菌屬於座囊菌綱（Dothideomycetes），是一類世界性分佈的真菌，種類非常豐富，寄主範圍十分廣泛。此屬的某些病原菌是水果及木本植物的重要病原，引起的症狀包括葉斑、枝枯、梢枯、莖腐、果腐、潰瘍及流膠等，進而可能導致樹木死亡。葡萄座腔菌屬的大部分成員多具有廣泛的寄主範圍，當其寄主植物遭遇到逆境或壓力時，便有機會造成廣泛的病徵。比較常見的病害有側柏枝枯病、木瓜與芒果蒂腐病、番石榴莖潰瘍病、桃梅等核果類果樹流膠病及櫻花流膠病等。近年來台灣種植之樹木常出現枝枯或樹幹潰瘍流膠等情形，如各地之木棉樹枝幹出現黑色潰瘍腫塊，以及苦楝樹皮出現縱裂流膠病徵，而國內並無此兩種病害之相關研究發表，我們試圖分離造成該兩種病害之病原菌，並進行分子鑑定，顯示Lasiodiplodia theobromae及L. pseudotheobromae兩種葡萄座腔菌屬真菌極有可能為造成此兩種病害的病原菌。木棉潰瘍病已在全台灣普遍的發生，遭受此病害感染之木棉樹會大量出現黑色潰瘍腫塊影響觀感及市容，可能導致整棵樹木愈來愈衰弱，嚴重時亦可能造成樹木死亡。而其近緣的病原菌L. pseudotheobromae則可能是造成苦楝流膠病的病原菌。在確定病害病原之後可進行相關防治研究及健康管理策略的擬定，將有助於降低此類病害發生情形。

"Canker diseases of trees are caused by fungal pathogens, a m o n g t h e m Botryosphaeria spp. is one important group. Botryosphaeriaceae is a genus-rich family in the Dothidiomycetes, containing numerous species with a cosmopolitan distribution. Some of the genera are important pathogens of fruit and woody trees causing symptoms such as leaf spot, dieback, stem-end rot, fruit rot, gummosis and cankers that can result in tree mortality. Most members of the Botryosphaeriaceae have a broad host range, and have been recognized as successful opportunistic pathogens that occasionally cause extensive disease symptoms when their plant hosts are subjected to unfavourable conditions. Common related diseases include dieback of Thuja orientalis, stem end rot of papaya and mango fruit, stem canker of guava, and gummosis of peach trees, plums and cheery trees. In recent years, trees emerged dieback, canker, gummosis and longitudinal crack symptoms frequently in Taiwan, for example, the canker and black tumors on Bombax ceiba and Gummosis on the bark of Melia azedarach, which are never been investigated or discussed by domestic research articles. Two fungal pathogens were isolated from theses two diseased samples and subjected to molecular identification, the results showed two Botryosphaeria spp., Lasiodiplodia theobromae and L. pseudotheobromae, are very likely responsible for the two diseases. Canker disease of Bombax ceiba occurs prevalently in Taiwan, the infection of the trunks and stems resulting in black tumors developed extensively, inaesthetic appearance, and may cause the decline of the host then can result in tree mortality at last. On the other hand, the relative species, L. pseudotheobromae, could be the pathogen that cause Gummosis of Melia azedarach. We can progress associated control research and draft health management strategy after verifying pathogens, which will contribute to reduce the occurrence of these diseases."