苹果细菌性枯枝病菌的生物学特性及抑菌药剂筛选

Biological Characteristics of Pseudomonas syringae pv.syringae Causing Shoot Dieback Disease on Apple and Screening of Bactericides

苹果细菌性枯枝病(Pseudomonas syringae pv.syringae)是造成苹果树枝枯的一种细菌性病害。为明确病原菌的生物学特性,筛选杀菌药剂,采用生长量法测定培养基、碳源、氮源、温度、pH、NaCl浓度和紫外线对病原菌生长的影响,并通过平板抑菌法和离体枝条接种法比较13种杀菌剂的室内毒力和防病效果。结果表明,苹果细菌性枯枝病菌在所测定的培养基中最适合在NA+5%蔗糖培养基上生长,在以蔗糖为碳源和牛肉膏为氮源时生长量最大。菌体适宜生长温度为25~30℃,最适温度为27℃;适宜生长pH 7~9,最适pH 7.5。在0.5%NaCl浓度下菌体生长良好,1%以上则抑制生长。49℃下处理10 min及紫外线照射6 min,能彻底杀死病原菌。室内毒力测定显示,3%噻霉酮ME、0.3%梧宁霉素AS、3%中生菌素WP、2%春雷霉素WP和30%王铜SC具有较好的抑菌效果,EC_(50)分别为6.43、16.36、22.57、35.31和36.65 mg/L。供试药剂的保护性防效以3%噻霉酮ME防效最优,可达82.66%;其次是2%春雷霉素AS和20%噻菌酮SC,防效分别可达77.14%和73.09%。

A shoot dieback disease caused by Pseudomonas syringae pv.syringae was found in several apple orchards in Ili,Xinjiang.In this study,the biological characteristics of the pathogen were tested and bactericides were screened to provide a scientific basis for epidemiology and control practices of this disease.The effects of culture medium,carbon source,nitrogen source,temperature,pH,NaCl concentration and ultraviolet on the growth of the pathogens were determined by growth method,and the indoor virulence and disease control effects of 13 fungicides were compared by plate inhibition method and in vitro branch inoculation method.The results show that the pathogen of apple bacterial blight is most suitable to grow on NA+5% sucrose medium,and the growth is the highest when sucrose is used as carbon source and beef paste as nitrogen source.The suitable temperature for cell growth is 25-30℃,the optimum temperature is 27℃,the suitable pH for growth is 7-9,and the optimum pH is 7.5.The bacteria grow well in the 0.5% NaCl,and are inhibited by NaCl concentration above 1%.The bacteria could be completely killed when they are treated at 49℃ for 10 min and ultraviolet irradiation for 6 min.Indoor virulence test show that 3% benziothiazolinone ME,0.3%tetramycin AS,3% zhongshengmycin WP,2% Kasugamycin WP and 30% copper(ll)busic choride SC have good bacteriostatic effect,and the EC50 is 6.43,16.36,22.57,35.31 and 36.65 mg/L,respectively.The protective effects of the tested agents were determined by in vitro branch inoculation method,and the results show that the control effect of 3% benziothiazolinone ME is the best,up to 82.66%,followed by 2% kasugamycin AS and 20% thiodiazole copper SC,which could reach 77.14% and 73.09%,respectively.