Resistance of the zymotic fluid of antagonistic actinomyces against Alternaria alternata.

The zymotic fluid of two antagonistic actinomycetes strains,SZF2 and SZF7,showed strong antagonistic activity against Alternaria alternata.The control efficiency and antagonistic mechanism of the zymotic fluid have been preceded,whose results suggested that the zymotic fluid of SZF2 and SZF7 not only inhibited spore germination,but also increased activities levels of peroxidase(POD) and polyphenol oxidase(PPO) of tobacco plant.We induced these properties to give an ability to against Alternaria alternate.Meanwhile,we inoculated detached leaves and irrigated 13-leaves-old tobacco plants with the zymotic fluid of two strains respectively.Results showed that the the zymotic fluid could reduce the disease index of Alternaria alternate,and in a pot experiment,the control efficiency of SZF2 and SZF7 was 48.94% and 50.13%,respectively.