施用 Bacillus mycoides AGB01 防治水稻紋枯病之田間試驗

水稻紋枯病 (rice sheath blight) 發生時常對其寄主造成嚴重損害，對於水稻產業亦是十分困擾的問題，目前對此病害之管理策略仍以化學藥劑防治為主，但長期施用化學藥劑易造成作物出現殘毒效應與環境衝擊，對施藥者也容易產生不良影響，故以非農藥防治策略管理植物病害或為較理想的管理方式。本研究即利用微生物製劑Bacillus mycoides AGB01於屏東、雲林等地進行田間試驗來防治水稻紋枯病，由調查結果顯示，此製劑能顯著降低水稻紋枯病罹病度最高達60%並增加水稻產量約14.9 %；進行田間試驗的同時，以本實驗室所開發之專一性引子對搭配即時定量聚合酶鏈鎖反應技術 (quantitative polymerase chain reaction, qPCR) 將田間樣本進行水稻紋枯病菌分子檢測並與水稻紋枯病之罹病度進行交互分析。正式試驗開始前先於國立屏東科技大學內進行田間預試驗，由此田間預試驗的結果顯示，水稻於種植後第44天，可達超過90%之病原菌檢出率，此時水稻紋枯病之田間罹病度約為5%。而於雲林的正式防治試驗田中的結果顯示：於水稻種植後第30天，施行本實驗室所開發之分子檢測技術即可獲得超過90%之病原菌檢出率，此時水稻紋枯病於田間之罹病度也為5%，顯示此分子檢測技術具田間檢測再現性；此外，以qPCR進行水稻紋枯病菌之田間定量試驗中，水稻紋枯病菌的田間檢出量，隨著施用微生物製劑的濃度提高，田間檢體檢出之水稻紋枯病菌的含量有降低的趨勢，此結果與病勢發展相符。未來希望能以本實驗室所開發之分子檢測技術，建立水稻紋枯病病勢發展之預測模型，並推廣上述微生物製劑於作物病害防治及分子檢測技術於病原檢測上，以此減少化學藥劑的使用並增進民眾之食品安全。

關鍵字

Rhizoctonia solani AG1 ；生物防治；蕈狀芽孢桿菌；即時定量聚合酶鏈鎖反應

並列摘要

Rice sheath blight caused by Rhizoctonia solani (Rs) Kuhn is a major soil borne disease causing economic losses to rice cultivation and known to be a serious problem for rice industry. At present, the management strategy of this disease is still dominated by chemical agents, but long-term application of pesticides is easy to cause residue poisons on crops and soil and may cause harmful effects to the applicator’s health and environment. Therefore, it would be more desirable to manage plant diseases with non-pesticide control strategies. In this study, the biological control agent Bacillus mycoides AGB01 was applied to control rice sheath blight in the fields. The molecular method (Rs qPCR assay) for pathogen evaluation based on quantitative polymerase chain reaction (qPCR) was performed to detect the present of R. solani in field-infected rice samples. The pathogen detection rates of the Rs qPCR assay were above 90%, when the symptomless rice leaf sheathes were used as tested samples. These data indicated that the Rs qPCR assay has high sensitivity for the in planta field-detection of R. solani. In addition, lower amount of R. solani were detetcted in the field which associated with the higher concentration of biological control agent applications. In the future, we hope to establish a predictive model of disease development, and promote the biological control agent and detection method on plant disease prevention and pathogen detection to reduce the use of pesticide and enhance the food safety of people.