臺灣相思樹維管束萎凋病之首次報導

First Report on Vascular Wilt of Acacia confusa in Taiwan

施欣慧(Hsin-Hui Shih) ； 蔡佳彬(Jia-Bin Tsai) ； 歐玠皜(Jie-Hao Ou) ； 李國維(Guo-Wei Lee) ； 傅春旭(Chuen-Hsu Fu) ； 陳啟予(Chi-Yu Chen)

《台灣林業科學》 35卷3期 (2020/09) Pp. 251-255

https://doi.org/10.7075/TJFS.202009_35(3).0005

摘要

相思樹（Acacia confusa Merr.）為臺灣原生樹種且廣泛分布於臺灣中低海拔地區，亦為常見之造林樹種。2018年首次於高雄六龜地區發現相思樹維管束之萎凋現象。苗木初期之徵狀為地上部枝葉呈現缺水狀，全株逐漸萎凋而致枯死。檢視根系，主根則呈現黑褐色化壞死，且莖基部之維管束組織亦呈現褐化。分離並純化罹病組織之病原菌，再結合真菌形態特徵及IGS序列（nuclear ribosomal DNA intergenic spacer，簡稱IGS）分析結果，此病原菌鑑定為Fusarium oxysporum f. sp. koae，此為臺灣新紀錄尖鐮孢菌之專化型。此外，調查六龜苗圃相思樹種子育苗之發病率，顯示約有60%～70%之相思樹實生苗會因罹患此病害而死亡，為相思樹實生苗重要之苗期病害。

關鍵字

相思樹 ； 維管束萎凋病 ； Fusarium oxysporum f. sp. koae

並列摘要

Taiwan acacia (Acacia confusa Merr.) is a native tree, is widely distributed at low and mid-elevations in Taiwan, and is commonly used for afforestation. A symptom of vascular wilt of Taiwan acacia was observed in Lioukuei District, Kaohsiung City in 2018. Seedlings initially appeared dehydrated, and gradually the entire seedling became wilted, eventually resulting in death. Black-brown necrosis occurred on the main roots and the cut ends of basal stems. The pathogen was isolated and purified from necrotic tissues. A fungus could be obtained from all affected seedlings. Judging from morphological features, this fungus is Fusarium oxysporum. Sequencing of the nuclear ribosomal DNA intergenic spacer (IGS) region of this fungus was performed, which suggested that this fungus is F. oxysporum f. sp. koae. This is the first report of this fungus in Taiwan. This fungus accounted for a 60%~70% mortality of seedlings at a Taiwan acacia nursery in Lioukuei. It is apparently an important disease in Taiwan acacia nurseries.

並列關鍵字

Acacia confusa ； vascular wilt ； Fusarium oxysporum f. sp. koae