番茄灰霉病和叶霉病拮抗细菌WXCDD51的筛选鉴定及其生防促生作用

Screening,Identification,Biocontrol and Growth Promoting Effects of Antagonistic Bacteria WXCDD51 of Tomato Gray Mold Disease and Tomato Leaf Mold Disease

从健康番茄植株根际土中分离筛选得到对番茄灰霉病菌和番茄叶霉病菌均有较强拮抗作用的生防细菌WXCDD51,通过形态特征、生理生化特征和16S r DNA序列分析鉴定其属于假单胞菌属(Pseudomonas sp.)。菌丝生长试验研究结果表明,该菌株的无菌滤液可以显著抑制番茄灰霉病菌和番茄叶霉病菌菌丝生长,抑制率分别为94.29%和94.06%;盆栽试验结果表明,该菌株可以有效防治番茄灰霉病和番茄叶霉病,防效分别为66.23%和69.45%;拮抗试验显示,该菌株对10种植物病原真菌均有不同程度的抑制作用,抑菌率在53.04%~94.59%;促生试验表明,该菌株对番茄种子萌发及幼苗生长均具有一定的促进作用,用浓度为10~6 cfu·mL^(-1)的菌液浸种处理,种子发芽率、胚根长度与对照相比分别增加80.0%和62.57%。用菌液(10~7 cfu·mL^(-1))灌根处理的番茄幼苗,其各项生理指标均显著高于对照;用菌液(10~7 cfu·mL^(-1))浸泡番茄果实可防止腐烂且对果实营养品质无不良影响。

In this study,a strain,named as WXCDD51,which has strong antagonistic effects on tomato gray mold disease and tomato leaf mold disease,was screened out from the rhizosphere of healthy tomato plants.Based on the morphological,physiological characteristics and 16 S r DNA sequence analysis,WXCDD51 was identified as Pseudomonas sp.Mycelial growth assay results showed that the sterile filtrate of WXCDD51 could significantly inhibit mycelial growth of Botrytis cinerea and Fulvia fulva,and the inhibition rates were 94.29% and 94.06% respectively.The pot experiment results showed that WXCDD51 made effective control of tomato gray mold disease and tomato leaf mold disease,the control efficiencies were 66.23% and 69.45%.By dual culture,strain WXCDD51 had different degrees of inhibition on 10 kinds of plant pathogenic fungi and the inhibition rate was about 53.04%–94.59%.The growth-promoting assay showed that WXCDD51 could promote seeds germination and seedling growth of tomatoes.After seeds were treated by the fermentation liquid of WXCDD51（10~6 cfu · mL^（-1））,the germination rate of seeds and radicle length increased 80.0% and 62.57% respectively comparing to the control.Under the treatment of the fermentation liquid of WXCDD51（10~7 cfu · mL^（-1））,almost all physiological indexes of treated seedlings were significantly higher than that of the control groups.After tomato fruits were soaked in fermented liquid of WXCDD51（10~7 cfu · mL^（-1））,tomato fruits decay can be prevented without affecting tomato fruits＇ quality.