菱角炭疽病之流行病學及非農藥防治

Epidemiological study and non-pesticide control of anthracnose disease of water caltrops

林彥安(Yen-An Lin)

指導教授 ： 孫岩章

國立臺灣大學/生物資源暨農學院/植物病理與微生物學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201610469

摘要

臺灣菱Trapa taiwanensis Nakai為一年生之水生作物，是臺南官田地區大宗之經濟作物，適合栽培於低窪的沼澤地或池塘。常見病害有炭疽病及白絹病兩種，炭疽病由Colletotrichum gloeosporioides Penzig所引起，主要為害植株葉片，尚可為害葉柄及果實。發病初期在葉表產生黑褐色之細小斑點，嚴重時多數病斑則會癒合成不規則之大班塊，葉片變薄凹陷且容易破裂。本研究主要在確認其病原性及官田地區之流行病學調查，並選取植物萃取液與拮抗微生物測試其防治潛力。所得之分離株經科霍氏法則測試分離株之病原性，再以分子生物學鑑定後，確認其為菱角炭疽病病原。將此病原以不同溫度培養，發現在25℃時菌絲生長速度最快。在流行病學調查中，發現需經過夏季長時間之降雨，田間方會開始出現菱角炭疽病之病株，此病害嚴重度會持續到12月，直到冬季結束。將田間病害嚴重度與前一個月總降雨量進行分析，發現2014年與2015年之相關係數分別為0.9371及0.9297；若將符合適合發病溫度、蒲氏二級風級、降雨三種條件之時數作為綜合因子進行分析，發現病害嚴重度與前一個月之綜合因子相關係數分別為0.9485及0.9271，顯示溫度、風速、降雨對於病害發生具正相關性。在研究非農藥防治方面，發現拮抗微生物之抑制效果較中草藥萃取液顯著。共9種中草藥之水萃取液對抑制菱角炭疽病效果不佳，而酒精萃取液雖在孢子抑制及菌絲生長抑制有良好效果，但實際應用於盆栽試驗時則未見顯著效果。在拮抗微生物防治方面，將盆栽試驗表現較佳之枯草桿菌(Bacillus subtilis)及放線菌YU01(Streptomyces sp.)在接種前三天施用於盆栽上，可達到約45%之防治效果。而木黴菌(Trichoderma asperillum)雖然在PDA上有良好抑制率，但在盆栽試驗中只有約30%防治效果。除非農藥資材外，農用藥劑中以待克利及貝芬替抑菌效果最佳。本研究亦以芒果炭疽病菌、草莓炭疽病菌、文旦炭疽病菌進行交叉感染試驗，發現此三種炭疽病皆不會在臺灣菱葉片造成病徵。

關鍵字

臺灣菱 ； 炭疽病 ； 流行病學 ； 非農藥防治

並列摘要

Water caltrops (Trapa taiwanensis Nakai) is a common annual aquatic crop in Guan Tian, Tainan. It adapts well in wetland like swamp or paddy areas. The most common diseases affecting water caltrops are anthracnose and sclerotium rot. The anthracnose disease of water caltrops is caused by Colletotrichum gloeosporioides Penzig. On water caltrops, the anthracnose can cause black spot symptoms that can coalesce into big lesions on leaves, petiole and fruits. This study is aimed to confirm the pathogenicity of anthracnose fungi on water caltrops and to investigate the epidemiology of this disease in Guan Tian area. Some herbal material extracts and antagonistic microorganisms are also evaluated for their potential for controlling this disease. Through the pathogenicity tools and molecular identification, we accomplish the Koch’s postulates of this disease. Culturing this pathogen at different temperatures showed that the pathogen grows best at 25℃. The epidemiological study from 2014 to 2015 showed that the disease occurred after a long period of raining summer season and may continue to the winter time. The correlation coefficient between last-monthly rainfall and disease severity in 2014 and 2015 are 0.9371 and 0.9297, respectively. If we combine the favorable rainfall, temperature and wind speed in together, the correlation coefficient between favorable hours and the disease severity in 2014 and 2015 can be as high as 0.9485 and 0.9271, respectively. Results indicated that the disease severity is positively correlated with favorable temperature, high wind speed and high rainfall. The non-pesticide control study showed that antagonistic microorganism had better effectiveness than herbal extracts. Water extracts of all herbal material showed low control rate on PDA. Although ethanol extracts of all nine herbal material showed significant inhibition rate in spore germination and mycelial growth tests, they didn’t have good effectiveness in the pot plant test. Both Bacillus subtilis and Streptomyces sp. YU01 has about 45 % control rate in pot plant test, when applied 3 days before inoculation with pathogen. Whereas Trichoderma asperillum expressed only about 30% control rate in pot plant test. Besides non-pesticide materials, difenoconazole and carbendazim showed best satisfactory to control this disease. We also found that anthracnose isolates from mango, strawberry and pomelo, cannot cause anthracnose disease on the water caltops.

並列關鍵字

Water caltrops ； anthracnose ； epidemiology ； non-pesticide control

參考文獻

2.阮逸明。1995。台灣農家要覽農作篇(一)。行政院農業委員會。386頁。

4.林宗俊、鄭可大、黃振文。2002。丁香及其主成分防治甘藍苗立枯病的功效。植物病理學會刊11(4)：189-198。

5.林秋琍、林宗俊、黃振文。2010。丁香油與植物營養防治十字花科蔬菜炭疽病之效果評估。植物病理學會刊 19(2)：167-176。

9.陳俊位、鄧雅靜、曾德賜。2009。功能性微生物製劑在有機作物栽培病害管理上之應用。臺中區農業改良場特刊96：147-181。

10.陳昇寬、陳文雄。2003。菱角金花蟲 Galerucella nipponensis (Laboissiere)(Coleoptera: Chrysomelidae)生態學初探。台南區農業改良場研究彙報 41:28-34。