中文摘要：

为探索农抗702在植物病害生物防治中的实际应用价值及对病原真菌的作用机理,采用生长速率法测定其抑菌谱,并以水稻纹枯病菌为研究对象,测定其作用下菌丝的电解质渗漏、蛋白质、核酸、Mg^2＋、K^＋含量的变化,及其对细胞膜麦角甾醇生物合成和水稻纹枯病菌超显微结构的影响.结果表明：农抗702对供试13种病原真菌均有较强的抑制作用,其中对油菜菌核病菌的作用最强,EC50为0.23μg·mL^-1;农抗702作用水稻纹枯病菌菌体后相对电导率增加72.2%;蛋白质、核酸、Mg^2＋、K^＋等胞内物质均发生了不同程度的渗漏;细胞麦角甾醇含量降低了92.0%;细胞膜轮廓不清、破损;细胞器严重损伤,有空泡化.抑制麦角甾醇合成、造成真菌细胞膜渗透增加是农抗702抑制真菌的主要机理.

英文摘要：

To explore the practical application value and action mechanisms of Ag-antibiotic 702 against pathogenic fungi, the inhibition spectrum of Ag-antibiotic 702 was studied by measuring the mycelium growth rate of pathogenic fungi, and the effects of Ag-antibiotic 702 on the membrane permeability of Rhizoctonia solani, a typical pathogenic fungus, were investigated, with the variations of myeelium electrolyte leakage and protein, nucleic acid, and Mg^2＋ and K^＋ contents under tile action of Ag-antibiotic 702 determined, and the effects of Ag-antibiotic 702 on the cell membrane ergosterol biosynthesis and uhramicrostructure observed. The results showed that the active products of Ag-antibiotic 702 had stronger inhibition effect on 13 test pathogens, among which, Sclerotinia sclerotiorum was most sensitive, with the ECs0being 0.23 3μg·mL^-1. As compared with the control, the relative electric conductivity of R. solani treated with Ag-antibiotic 702 was increased by 72.2% , the contents of protein, nucleic acid, and Mg^2＋ and K^＋leaked from the R. solani cells were all increased, while the ergosterol content was decreased by 92.0%. The cell membrane outline was not clear, organelles were inhibition of ergosterol biosynthesis action mechanisms of Ag-antihiotic badly damaged, and vacuole appeared. It was suggested that the and the increase of membrane permeability could be the main 702 against pathogenic fungi.