新疆红枣叶斑病菌生物学特性及室内药剂筛选研究

Study on Biological Characteristics of Leaf Spot Bacteria of Zizyphus jujuba in Xinjiang and Fungicide Screening in Laboratory

以新疆地区2株红枣叶斑病菌Alternaria tenuissima和A.alternata菌株为试材,采用菌丝生长速度法研究了温度和pH对2种病原菌生长的影响,并采用菌丝生长抑制率法和孢子萌发抑制率法进行了室内防治药剂的筛选,以期明确红枣叶斑病病菌的生物学特性和有效防治药剂。结果表明:这2种病原菌菌丝生长的适宜温度为25～30℃,适宜pH为7～9;70%代森锰锌对A.tenuissima和A.alternata菌丝生长以及孢子萌发的抑制效果最好,抑制菌丝生长的EC50分别为0.053、0.054g/L,抑制孢子萌发的EC50分别为0.021、0.019g/L,70%代森锰锌可作为枣树叶斑病的首选药剂。

Taking two strains of leaf spot bacteria of Zizyphus jujuba Alternaria tenuissima and A.alternata as materials,the effect of temperature and pH on the growth of Alternaria tenuissima and A.alternata were studied using mycelia growth speed method.The inhibition methods of mycelia growth and spore germination were tested to screen the best fungicide from 5 fungicides,in order to definite the biological characteristics and screen effective fungicides against the leaf spot pathogen of Zizyphus jujuba.The results showed that the optimum temperature for mycelial growth of he pathogen was 25~30℃ and the optimum pH ranged from 7 to 9.The 70% Mancozeb could significantly inhibit mycelium growth of the pathogen,the EC50 values were 0.053 and 0.054 g/L,and could greatly depress spore germination with inhibition,the EC50 values were 0.021 and 0.019 g/L.The 70% Mancozeb will be preferred to control leaf spot disease of Zizyphus jujube in Xinjiang.