黄瓜枯萎病拮抗菌Burkholderia gladioli L1-3的分离鉴定及防病促生效果

Isolation and Identification of Cucumber Fusarium Wilt Antagonistic Bacteria Burkholderia gladioli L1-3 and Effect of Disease Prevention and Health Promotion

为筛选出拮抗黄瓜枯萎病的生防细菌,从甘肃省22块多年连作黄瓜的枯萎病发生地块采集土样,采用平板对峙法筛选拮抗菌株,基于形态特征、生理生化特性及基因序列分析对拮抗菌株进行鉴定;并且测定拮抗菌株的抑菌谱及其对黄瓜枯萎病的防病促生效果。结果表明:分离、筛选出的6株对尖孢镰孢菌黄瓜专化型具有较强拮抗作用的细菌菌株均被鉴定为唐菖蒲伯克霍尔德氏菌(Burkholderia gladioli)。施用L1-3菌剂对黄瓜枯萎病的防治效果达64.71%,黄瓜幼苗的根系活力、叶绿素含量、POD和SOD活性均显著高于对照,并且对尖孢镰孢菌甜瓜专化型、尖孢镰孢菌西瓜专化型、尖孢镰孢菌十字花科专化型、辣椒腐霉菌、辣椒灰葡萄孢菌、辣椒立枯丝核菌、辣椒疫霉菌、茄链格孢均有较强的拮抗效果。

In order to screen out biocontrol bacteria to prevent cucumber Fusarium wilt,this experiment collected soil samples from 22 Fusarium wilt infected plots planted with cucumber in Gansu Province for successive years;screened out antagonistic strains by plate confrontation method;and carried out identification based on morphological,physiological and biochemical characteristics and gene sequencing analysis.The inhibiting spectrum of antifungal strain and its effect of disease prevention and health promotion were determined.The results showed that 6 separated and screened out strains had stronger rivalry effect to Fusarium oxysporum f.sp.cucumerinum Owen.They were identified as Burkholderia gladioli.The control effect of applying L1-3 fungicide on cucumber Fusarium wilt was 64.71%.The root system activity of cucumber seedlings,chlorophyll content,POD and SOD activities were all significantly higher than that of the contrast.Besides,L1-3 had stronger antagonism effects on all pathogenic fungi,including Fusarium oxysporum f.sp.melonis,Fusarium oxysporum f.sp.niveum,Fusarium oxysporum f.sp.conglutinans,Pythium spinosum,Botrytis cinerea,Rhizoctonia solani,Phytophthora capsici and Alternaria solani.