醉鱼草内生细菌ZJ1的生物学特性及防病促生效果

Biological characteristics and plant growth-promoting and biocontrol properties of endophytic bacterium ZJ1 from Buddleja lindleyana

为推动生物防治技术在实践中的应用,本研究采用稀释涂布平板法对菌株ZJ1的致死温度和酸碱度进行测定,结果表明,菌株ZJ1的致死温度为96℃、可存活20 min;致死pH为≤4或≥14。而生物膜能够吸附土壤中的金属离子改善植物生长环境,帮助生防菌株更好地定殖在植物表面,发挥生防功能。采用菌膜检测法观察几种常见金属离子对菌株ZJ1生物膜形成的影响,结果表明,0.3%的Zn2+、Mn2+、Cu2+和Fe2+会抑制菌株ZJ1产生生物膜,但同浓度的Mg2+、K+均可促进菌株ZJ1生物膜的产生;进一步采用96微孔板定量法对菌株ZJ1生物膜形成能力进行了测定,结果表明,菌株ZJ1为强生物膜形成株。室内盆栽试验结果表明,菌株ZJ1发酵液10×稀释液对番茄早疫病的保护效果最高,达到95.54%,菌株ZJ1发酵液200×稀释液对番茄灰霉病的治疗效果最高达,到91.99%。综合考虑菌株ZJ1对两种病害的治疗和保护效果,菌株ZJ1发酵液稀释200×防治效果最好。且菌株ZJ1发酵液10~200×均具有促生效果。因此,菌株ZJ1是一株具有生防潜力的微生物菌株。

The objective of this study was to promote the application of biological control technology in a practical setting.As determined by the dilution coating plate method,the lethal temperature for ZJ1 was 96℃for 20 min and the lethal pH was≤4 or≥14.Biofilm can absorb metal ions in soil to improve the plant growth environment,and can help biocontrol strains to colonize the surface of plants and exert their biocontrol functions.The effect of several common metal ions on the biofilm formation of ZJ1 was evaluated using a bacterial membrane detection method.It was found that the biofilm production of ZJ1 was inhibited by 0.3%Zn2+,Mn2+,Cu2+,and Fe2+,but promoted by 0.3%Mg2+or K+.The biofilm formation ability of ZJ1 was further measured using a quantitative 96-well microplate method,and the results showed that ZJ1 was a strong biofilm-forming strain.The results of an indoor pot experiment showed that the protective effect of a 10-fold dilution of ZJ1 fermentation broth on tomato early blight was up to 95.54%,and the therapeutic effect of a 200-fold dilution of ZJ1 fermentation broth on tomato gray mold was up to 91.99%.Considering the therapeutic and protective effects of ZJ1 against these two disease-causing organisms,the 200-fold dilution of ZJ1 fermentation broth had the best control effect.The fermentation broth of ZJ1 at 10-fold to 200-fold dilution also had a growth-promoting effect on tomato plants.Therefore,strain ZJ1 is a microbial strain with biocontrol potential.