Antifungal effect and mechanism of chitosan against the rice sheath blight pathogen, Rhizoctonia solani
The antifungal properties and mechanism of three types of chitosan against the rice sheath blight pathogen, Rhizoctonia solani, were evaluated. Each chitosan had strong antifungal activity against R. solani and protected rice seedlings from sheath blight, in particular, two types of acid-soluble chitosan caused a 60–91 % inhibition in mycelial growth, 31–84 % inhibition of disease incidence, and 66–91 % inhibition in lesion length. The mechanism of chitosan in protection of rice from R. solani pathogen was attributed to direct destruction of the mycelium, evidenced by scanning and transmission electron microscopic observations and pathogenicity testing; indirect induced resistance was evidenced by the changes in the activities of the defense-related phenylalanine ammonia lyase, peroxidase and polyphenol oxidase in rice seedling. To our knowledge, this is the first report on the antifungal activity of chitosan against rice R. solani.
KeywordsAntifungal activity Antifungal mechanism Chitosan Rhizoctonia solani Rice
This project was supported by Zhejiang Provincial Natural Science Foundation of China (Y3090150), Zhejiang Provincial Project (2010R10091), the Fundamental Research Funds for the Central Universities, the Agricultural Ministry of China (nyhyzx 201003029; 201003066; 201303015), State Education Ministry and Key Subject Construction Program of Zhejiang for Modern Agricultural Biotechnology and Crop Disease Control (2010DS700124-KF1101; 2010DS700124- KF1203).
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