苗栗地區水稻徒長病之發生情形與抗藥性分析

The occurrence of Bankanae disease and fungicide resistance of Fusarium fujikuroi on rice paddy, seedlings and seeds from Miaoli

鄭志文(Zhi-Wen Zheng) ； 張素貞(Su-Jein Chang) ； 朱盛祺(Sheng-Chi Chu)

《苗栗區農業改良場研究彙報》 4期 (2016/10) Pp. 59-72

摘要

水稻徒長病(Bakanae disease of rice)，係由病原真菌Gibberella fujikuroi (Sawada) Wollenweber (有性世代) , Fusarium jujikuroi (無性世代)所引起。本次試驗於苗栗地區進行，試驗時間為2012 至2013年。試驗內容包含調查田間育苗期與本田期發病情形，檢測稻種帶菌率與育苗盤播種罹病率之關係，並進行徒長病菌之抗藥性測試。首先檢測由苗栗地區育苗場共收集13種水稻品種，共計52個稻種樣品，利用FFC鑑別性培養基檢測稻種帶菌率，以2012年第一期作合農77號15.3%最高：秧苗播盤發病率以2012年第一期作合農84號142.3株/每盤最嚴重，且一期作稻種帶菌率與秧苗盤發病率均較二期作高，驗證田間水稻徒長病普遍發生於水稻一期作。調查苗栗縣轄區內育苗場培育之秧苗發病率，以2012年第2期作台南11號10.7株/每箱最高；調查本田期發病率以2012年第1期作台稉8號30.4%最為嚴重。利用92株徒長病菌進行抗藥性試驗，發現25%撲克拉乳劑稀釋500倍、1,000倍僅抑制菌絲生長，無法完全殺死病原菌， 25.9%得克利水基乳劑2,000倍，可有效殺死病原菌達到完全抑制的效果。此結果顯示若稻種消毒不完全，徒長病菌仍可殘存於稻種上，並造成後續之危害。綜合本研究結果，為降低徒長病之發生，品種及藥劑選擇益顯為重要，故建議選擇水稻良種三級繁殖制度之地區特色品種的稻種，以較有效藥劑25.9%得克利水基乳劑2,000倍進行稻種消毒作業。

並列摘要

Bakanae disease of rice is caused by Gibberella fujikuroi (Sawada) Wollenweber in sexual generation, Fusarium fujikuroi in asexual generation. This study was conducted with samples collected from the first and second rice crops of Miaoli between 2012 and 2013. Fifty-two rice samples from 13 rice varieties were collected from hatcheries in Miaoli. FFC differential medium was used to detect the rate of rice seeds infested by F. fujikuroi. The highest rate 15.3% of TNG 77 was detected from the first crop of 2012. The highest disease incidence of seedling tray, 142.3 plants / tray of TNG 84, was detected from the first crop of 2012. Both the infection rate of rice seeds and the disease incidence of seedling tray detected from first crop were higher than those from second crop. The widespread occurrence of Bakanae disease was confirmed from the first crop. The highest disease incidence of seedling tray, 10.7 plants / tray of TN 11, was detected from the second crop of 2012 from hatcheries in Miaoli. The highest rate 30.4% of field TK 8 was detected from the first crop of 2012. The results of fungicideresistant test has shown that 92 F. fujikuroi strains could be inhibited by 500- and 1000-fold dilution of 25% prochloraz EC, and 2000-fold dilution of 25.9% tebuconazole EW. However, the F. fujikuroi mycelium could recover on potato dextrose agar by prochloraz treatment. It suggests that the incompletely disinfected rice seeds could enhance the outbreak of the bakanae disease. Therefore, it is important to choose correct varieties and fungicide for reducing the incidence of Bakanae disease.

並列關鍵字

Fusarium fujikuroi ； FFC differential medium ； Bakanae disease