探討Fusarium solani對葉稻熱病之生物防治效果

Study on Biological Control of Rice Blast by Fusarium solani

林秀娟(Hsiu-Chuan Lin)

指導教授 ： 陳麗鈴 ； 謝清祥

國立屏東科技大學/農學院/熱帶農業暨國際合作系所/碩士(2010年)

https://doi.org/10.6346/NPUST.2010.00252

摘要

由Pyricularia oryzae引起之稻熱病（rice blast）為傳染力極強的水稻病害，幾乎遍布於全世界的稻米產區，當環境適合此病害發展時，最高可造成90% 的產量損失。為了減低化學農藥的使用並提高食品安全性，以生物防治法來抑制稻熱病為當前研究之趨勢。本研究由土壤中篩選能利用蔬菜組織營養之微生物70株，再以相同蔬菜組織培養分離株並製成醱酵液以測試其對P. oryzae及稻熱病之抑制效果。病害抑制結果顯示15株分離株於塗抹葉可完全抑制病斑產生，其中4株醱酵液可能因對於P. oryzae孢子發芽後之生長有抑制作用而抑制病害的發生，有2株菌株（KS-F14, KS-B23）對於塗抹葉之上位葉抑病效果顯著。其中抑病效果最佳的KS-F14經形態及分生鑑定結果為Fusarium solani，其醱酵液有效抑病物質之來源主要為分泌至菌絲外的代謝產物，能誘導水稻產生系統性抗病，耐高溫及pH 4~10環境下都能作用，但極端pH會破壞其活性，且為不可逆的反應，可被離子交換樹脂及活性碳吸附。處理稻株所產生之抗病效果至少可以維持14天，醱酵液稀釋至2000倍仍有很好的抑病效果，於一片葉上施用2次即可降低所有接種葉之感染率及病斑面積，極具開發為生物防治資材的潛力。KS-F14菌株所產生之抑病物質以水、甲醇、乙醇萃取效果最佳。本研究為第一篇發現F. solani之醱酵液可誘導水稻產生系統性抗病的報告。

關鍵字

Pyricularia oryzae ； 稻熱病 ； 生物防治 ； Fusarium solani ； 代謝產物 ； 系統性抗病

並列摘要

Rice blast caused by Pyricularia oryzae is one of the most destructive fungal diseases of cultivated rice worldwide, and could cause yield losses up to 90% when the environment is favorable. Although the disease can be managed by fungicide application, recent studies have focused on developing alternative control methods to reduce the negative impact on environment caused by overuse of chemicals and to increase food safety. In this study, we aimed to screen microorganisms from soil for biological control of rice blast. Seventy soil microorganisms capable of utilizing vegetable tissues for growth were isolated from KS soil, and liquid cultures of them were prepared using liquid medium containing the same vegetable tissues. Liquid cultures were individually spread on rice leaves to test their ability to control rice blast. Results showed that liquid cultures of 15 isolates completely inhibited rice blast on the leaf treated with liquid culture. Four of them inhibited the disease by effects on the growth of P. oryzae after germination. Two of them (KS-F14, KS-B23) could reduce rice blast on leaves adjacent to the treated leaf indicating an induced systemic resistance effect. Fungal isolate KS-F14 was identified as Fusarium solani and the substances in its liquid culture responsible for disease inhibition existed mainly in liquid phase, not in mycelium. The active substances could be extracted by water, methanol and ethanol, was heat stable, and functional in pH 4~10 but inactivated by pH 2 or 12 permanently, adsorbed partially or completely by ion exchange resins and activated charcoal. The liquid culture maintained its disease inhibitory effects for at least 14 days or at 2000-fold dilution, and application for two times was enough to inhibit disease, which showed great potential of F. solani KS-F14 as a biocontrol agent. This is the first report of F. solani inhibiting rice blast by induced systemic resistance in rice.

並列關鍵字

rice blast ； Pyricularia oryzae ； biological control ； induced systemic resistance ； Fusarium solani ； liquid phase

參考文獻

石信德、黃振文（2010）鏈黴菌生物製劑之應用潛力。農業生技產業季刊 24:38-46。

許嘉伊（2010）全球生物農藥產業概況與未來展望。農業生技產業季刊 24:1-7。

楊靜惠（2010）由土壤中分離之Humicola phialophoroides誘導寄主產生抗病性之研究。國立中興大學植物病理學系研究所碩士論文。

Lee, C. H., B. J. Kim, G. J. Choi, K. Y. Cho, H. Yang, C. Shin, S. Min, and Y. Lim. 2002. Streptomyces with Antifungal Activity against Rice Blast Causing Fungus, Magnaporthe grisea. Journal of Microbiology and Biotechnology 12:1026-1028.

Knudsen, I. M. B., J. Hockenhull, D. F. Jensen, B. Gerhardson, M. Hokeberg, R. Tahvonen, E. Teperi, L. Sundheim, and B. Henriksen. 1997. Selection of Biological Control Agents for Controlling Soil and Seed-Borne Diseases in the Field. European Journal of Plant Pathology 103:775-784.