台灣十字花科蔬菜炭疽病之發生與其病原菌的鑑定

The Occurrence of Cruciferous Vegetable Anthracnose in Taiwan and Identification of Its Pathogen

林秋琍( C. L Lin) ； 黃振文( J. W Huang)

《植物病理學會刊》 11卷4期 (2002/12) Pp. 173-178

https://doi.org/10.6649/PPB.200212_11(4).0002

摘要

近年來，在台灣主要蔬菜栽培區，包括雲林、苗栗、花蓮、高雄及台中等地，發現白菜葉片出現許多淡黃色至灰褐色圓形斑，中間白色透明發亮，有時會有穿孔現象，多數病斑會癒合成大形壞疽斑；病斑主要發生於下位葉，嚴重時受害葉片會呈乾枯下垂的病徵。此病害大多發生於有機蔬菜栽培區。將罹病組織分離到菌株回接於白菜，四天後，植株葉片會再產如自然感染的病徵。進一步，將具病原性之PA-01及PA-19兩菌株分別接種其他不同栽培種之十字花科蔬菜、莧菜、茼蒿、萵苣、芹菜、甕菜及菠菜等，結果發現只有十字花科蔬菜出現病徵。在馬鈴薯葡萄糖瓊脂平板培養本病原菌的PA-01及PA-19菌株發現它們的菌絲平鋪生長於培養基表面，呈白色或墨綠色至黑色，會產生鮭紅色分生孢子堆；分生孢子單胞，圓筒形或紡錘形，透明無色，內有大型油滴，大小為15-21x3.0-5.5 mm；具附著器，呈圓形至不規則形；分生孢子盤於葉表皮下埋生，孢子盤內散生剛毛，剛毛深褐色。本菌的最適生長溫度與分生孢子發芽及附著器形成的最適溫度皆為24-28°C。綜合上述兩菌株的形態、產孢方式及病原性等特性，將本病原菌鑑定為Colletotrichum higginsianum Sacc. apud Higgins。

關鍵字

白菜 ； 炭疽病 ； Colletotrichum higginsianum ； 寄主範圍

並列摘要

Recently, Pak-choi (Brassica rapa L. Chinese Group) anthracnose has become severe in organic farms at Yunlin, Miaoli, Hisnchu, Hualien, Kaohsiung and Taichung Counties in Taiwan. The symptoms consisted of small, circular to irregular, pale gray to straw-colored lesions occurring in lower leaves. The lesions may become perforated with splits through the dried necrotic area. Under favorable conditions, the numerous lesions often coalesce and form large irregular spots, and infected leaves became yellowing and wilting. Symptoms on mid-ribs, petioles and stems appeared as sunken and elongated lesions with gray to dark, brown or black border. The fungus was consistently isolated from diseased Pak-choi leaves and its pathogenicity was confirmed by spraying the conidial suspension onto the leaves of cruciferous and other pathogenicity was confirmed by spraying the conidial suspension onto the leaves of cruciferous and other families vegetables. The symptoms developed only on inoculated plants of cruciferous vegetables. Other inoculated plants remained symptomless. The colonies of the pathogen on PDA plates usually had little aerial mycelia, but occasionally produced fluffy patches of white aerial mycelia or produced the dark mycelial bodies onto the agar. Conidia were formed in orange cinnamon to clay masses, and setae were not developed in culture, but were produced on the host. The pathogen produced rod-shaped, hyaline, one-celled conidia in acervuli. The rang of conidial size was 15-21 x3.0-5.5μm. According to the morphology and the pathogenicity on cruciferous plants, the pathogen was identified as Colletotrichum higginsianum Sacc. apud Higgins. The optimum temperatures for mycelial growth, conidial germination, and appressorial formation of C. higginsianum isolates PA-01 and PA-19 were at 24-28°C. C. higginsianum showed the pathogenicity on the weeds (lindernia antipoda (L.) Aslton) and was able to survive better in soil with pak-choi plant debris.

並列關鍵字

Cruciferous vegetable anthracnose ； Pak-choi ； Colletotrichum higginsianum