殺菌劑抗藥性發生之監測與預防

Abstract

殺菌劑抗藥性存在已久，倍使植物保護工作者困擾之問題之一，綜觀現今累計之研究，四大類藥劑可明顯誘導植物病原真菌產生抗藥性，分別為demethy1ation in hibitor (DMI )、benzimidazole、dicarboximide及phenylamide抗藥性問題既已存在，其監測工作則為刻不容緩之要務，其目的及重要性分別為探討抗藥性產生之可能性、預測抗藥性問題之產生、測定抗藥性管理策略、探知抗藥性之進展、協助地區性使用殺菌劑之選擇、抗藥性之基礎研究：而於監測工作進行時，首要訂定抗藥性之基準點(baseline)，而後訂定測定方法，由於殺菌劑之作用機制不同，故抗藥性之監測方法亦隨之不同，常用者為測定分生胞子發芽率、發芽管之伸長、吸器之產生及菌絲生長之抑制作用；至於絕對寄生菌則測定分生胞子之發芽、發芽管之伸長及接種後病斑擴展之抑制作用。抗藥性之預防為抗藥性研究工作之另一重點，可執行之方向分為開發新防治藥劑、藥劑輪流使用、藥劑混合使用、改變施用方式及施用時期、限制使用次數，而另一預防措施為採用耕作防治策略，可行之方法為栽種抗病品種、改變耕作方式、及進行病害預測等。 Fungicide-resistance is a old and big problem of plant protection in the field. The four group of fungicide was found to induce the fungicide-resistance is demethylation inhibition(DMI), benzimidazole, dicarboximide and phenylamide. The purpose and importance for fungicide-resistance monitoring are to investigate suspected cases of practical resistance, to predict the appearance of resistance problems, to check resistance management strategies, to track the progress of resistance with time, to guide fungicide selection at the local level, and to advance basic understanding. The baseline must be determined before fungicide-resistance monitoring. But the methods to determine the baseline are varied according to the fungicides and pathogen. The methods used popularly are the germination of spore, the elongation of germ-tube, the inhibition of the formation of haustoria and mycelial growth. Another importance work for fungicide-resistance is the control. New disease control agents, the use of mixtures, rotation of disease control agents, limitation of use, integrated control strategies was concerned the best ways to control fungicide-resistance problem.