陕西核桃黑斑病病原菌鉴定及药剂防治研究

Study on Identification of Walnut Blight Pathogenic Bacteria and Its Chemical Control in Shaanxi Province

核桃黑斑病是危害核桃生产的重要细菌性病害,近年来在陕西严重发生。为探究陕西省核桃黑斑病的病原菌种类,制定核桃黑斑病的田间防治策略。采用组织分离法对陕西省内核桃黑斑病的病原菌进行分离纯化,获得纯培养物,通过形态特征、生理生化特性及16S rDNA序列分析,获得2种病原株系HTX和HTP,分别鉴定为野油菜黄单胞杆菌(Xanthomonas campestris)和成团泛菌(Pantoea agglomerans)。通过对21种药剂进行室内抑菌试验,筛选出7种药剂对2种病原菌株系均有明显抑制作用。通过室内毒力测定和田间防治试验,结果表明中生菌素、春雷霉素、噻霉酮、琥胶肥酸铜和噻唑锌对核桃黑斑病危害的叶片、果实的防治效果均在67.67%、61.53%以上,防治效果好,可用于核桃黑斑病的田间防治。

Walnut blight is an important bacterial disease whichthreatened walnut production and occurred severely in Shaanxi province in recent years.To confirm the pathogenic bacteria of walnut blight in this region and fortaking measures for control of this disease in the field,diseased leaves and fruits of walnut collected from Shaanxi province were used to isolate the pathogen and purification of pure isolate in this study.Two pathogenic bacteria,namely HTX and HTP,were isolated and purified from samples with typical symptoms.The results showed that two strains of the pathogenic bacteria,HTX and HTP,were obtained and identified as Xanthomonas campestris and Pantoea agglomerans by colony morphological,physiological and biochemical characteristics,and 16S rDNA sequence analysis.The results of bacteriostatic experiment showed that seven out of twenty-one tested chemicals had obvious inhibition effects on the two strains of pathogenic bacteria.Based on toxicity test and field trials of the seven bactericides to leaves and fruits infected with walnut blight,the control effects of Kasugamycin,Zhongshengmycin,Benziothiazolinone,Copper succinate,and Cupric succinate against the disease were more than 67.67%and 61.53%,respectively.Therefore,these five bactericides can be potentially used for control of walnut blight.