白菜软腐病病原菌鉴定及地衣芽孢杆菌XW02对其的抑制作用

Identification of Soft Rot Disease Pathogen of Chinese Cabbage and Inhibition Effect of Bacillus licheniformis XW02

软腐病是白菜的三大主要病害之一,严重影响白菜产量和品质。利用微生物防治白菜软腐病具有绿色环保且不产生耐药性的优势,是农业健康发展的必然趋势。采用组织分离法,从大田白菜软腐病病株中分离、纯化出病原菌;利用大白菜致病性试验,对白菜软腐病的致病菌株进行筛选;利用分子生物学方法对致病菌株的16S rDNA扩增并测序,通过BLAST和GenBank比对,采用邻接法构建系统发育树确定其分类地位。结果显示,白菜软腐病的致病菌株为H3,属于胡萝卜软腐果胶杆菌(Pectobacterium carotovorum subsp. carotovorum)。通过双层培养法从10株地衣芽孢杆菌(Bacillus licheniformis)中筛选出对H3菌株抑制效果最好的菌株XW02,抑菌圈直径达到49.33 mm。对XW02菌株进行抑菌谱试验和盆栽防效试验,抑菌谱试验结果显示,XW02菌株对黄瓜角斑病菌、辣椒疮痂病菌、大白菜黑腐病菌和柑橘溃疡病菌均有一定的抑制作用,其中对黄瓜角斑病菌的抑菌作用最大,对辣椒疮痂病菌的抑菌作用最小;盆栽防效试验结果显示,XW02菌株对白菜软腐病具有很好的防治效果,防效为60.20%,较对照药剂春雷霉素的防效高6.12百分点。地衣芽孢杆菌XW02具有很好的生防潜力,为白菜软腐病的生物防治提供了新资源。

Soft rot is one of the three main diseases of Chinese cabbage,which seriously affects the yield and quality of Chinese cabbage.The use of microorganisms to control soft rot disease of Chinese cabbage has the advantages of being environmentally friendly and not producing drug resistance,which is an inevitable trend for the healthy development of agriculture.Using tissue isolation method,the pathogen were isolated and purified from the soft rot disease strains of Chinese cabbage in the field.The pathogenic strains were screened using pathogenicity test of Chinese cabbage.The 16S rDNA of pathogenic strains were amplified and sequenced,comparing them with BLAST and GenBank,and a phylogenetic tree was constructed using adjacency method to determine their taxonomic status.The results showed that the pathogenic strain of Chinese cabbage soft rot disease was H3,belonging to Pectobacterium carotovorum subsp.carotovorum.The strain XW02 with the best inhibitory effect on H3 was selected from 10 Bacillus licheniformis strains using a double-layer culture method,and the diameter of the inhibition zone reached 49.33 mm.The antibacterial spectrum test and potted plant control effect test of XW02 were conducted.The results of the antibacterial spectrum test showed that XW02 had certain inhibitory effects on Pseudomonas syringae pv.Lachrymans,Xanthomonas campestris pv.Vesicatoria,Xanthomonas campestris pv.Both campstris and X.citri had certain inhibitory effects.Among them,the antibacterial effect on P.syringae pv.Lachrymans was the greatest,and the antibacterial effect on X.campestris pv.Vesicatoria was the smallest.The results of the potted plant control test showed that XW02 had a good control effect on Chinese cabbage soft rot disease,with a control effect of 60.20%,which was 6.12 percentage points higher than the control agent kasugamycin.Therefore,B. licheniformis XW02 has great biocontrol potential and provides a new resource for the biologicalcontrol of soft rot disease in Chinese cabbage.