产气克雷伯氏杆菌 Klebsiella aerogenes S2对植物病原真菌的抑菌活性及番茄促生效果

本研究以广西红树林的根际土壤为材料, 利用选择性培养基分离筛选多功能菌株, 并利用生理生化和分子生物学相结合的方法进行鉴定?采用平板对峙法测定筛选获得的菌株对几种植物病原真菌的拮抗效果, 同时通过盆栽试验和发芽试验研究其对番茄幼苗和种子的促生效果, 从而挖掘兼具促生防病功能的植物根际促生菌(plant growth-promoting rhizobacteria, PGPR)?经筛选获得一株具有溶磷及分泌生长素(indole-3-acetic acid, IAA)能力的细菌菌株S2, 经鉴定该菌株属于克雷伯氏菌属Klebsiella, 其对禾谷镰孢Fusarium graminearum, 玉蜀黍平脐蠕孢Bipolaris maydis等3种植物病原真菌具有一定的拮抗效果, 菌株发酵液浓度为1×104?2×104 cfu/mL时对番茄种子和幼苗的促生效果最好?综上, 菌株S2 是一株新型且兼具促生防病效果的多功能PGPR菌株, 该结果为绿色现代农业开发土壤微生物菌肥和植物生长调节剂提供优质菌源参考?

Antifungal activity of Klebsiella aerogenes S2 against plant pathogenic fungi and its growth promotion to tomato

In this study, the multi-functional strains were isolated and screened by selective medium from rhizosphere soil of mangrove in Guangxi province. The classification status of biocontrol bacteria was identified based on colony phenotype, physiological and biochemical characteristics and 16S rRNA gene sequence. And the antagonistic effect of the screened strains against variety plant pathogenic fungi were evaluated by plate confrontation method, and the growth-promoting effect on tomato seedlings and seeds were studied by pot experiment and germination experiment, so as to excavate plant growth-promoting rhizobacteria with the function of promoting growth and preventing disease. A bacterial strain S2 that can dissolve phosphorus and secrete IAA (indole-3-acetic acid) was screened and identified as Klebsiella. It displayed antagonistic activity on three plant pathogenic fungi, including Fusarium graminearum, Bipolaris maydis and so on. In addition, the fermentation broth concentration of the strain S2 was 1×104 cfu/mL and 2×104 cfu/mL, respectively, which had the best growth promotion effect on tomato seedlings and seeds. In conclusion, strain S2 is a new multi-functional PGPR strain with both growth promotion and disease prevention, which provides a high-quality reference for the development of soil microbial fertilizer and plant growth regulators in green modern agriculture.