烟草复合微生物菌剂的构建及其促生抗病效应

Establishment of tobacco composite microorganism agent and its effects on plant growth promotion and disease resistance

植物根际功能菌是微生物肥料的重要菌种资源,在农业生产中发挥重要的作用。利用稀释涂布法对采集自贵州省遵义市发病烟区的健康烟株根际土壤进行根际细菌的分离纯化,研究根际细菌解磷、分泌吲哚乙酸、抗烟草青枯病菌的能力以及功能菌株间的拮抗作用,构建复合微生物菌剂,并对该菌剂的促生抗病效果开展评价。结果表明,烟草根际细菌LSNSY15-4对烟草具有最佳的促生效果,处理的烟草株高、根长和鲜重相对于对照组增幅分别为22.45%、35.57%和155.72%;烟草根际细菌D对烟草青枯病菌具有较好的拮抗效果,抑菌圈直径为21.40 mm,分子鉴定结果表明促生菌株LSNSY15-4为泛菌属(Pantoea)微生物,拮抗菌D为贝莱斯芽孢杆菌(Bacillus velezensis);随后,在明确D和LSNSY15-4具有亲和性的基础上,将菌株D和LSNSY15-4体积比1:1混合培养24 h,获得复合微生物菌剂,发现该菌剂可促进烟草植株生长,处理的烟草株高、叶片数和鲜重相对于空白对照组增幅分别为10.21%、32.26%和54.67%,且对烟草青枯病菌抑菌活性具有增效作用,有效地防控烟草青枯病的发病程度。该研究结果为烟草土传病害的安全有效防治提供了新途径。

Plant rhizosphere functional bacteria are important species resources for microbial fertilizer,and they play im-portant roles in agriculture production.In this study,rhizosphere bacteria were isolated and purified from rhi-zosphere soil of healthy tobacco plants collected from diseased tobacco areas in Zunyi City,Guizhou Province by dilution plate method,and then the capability of phosphate-dissolving,indoacetic acid-secreting,disease resistance among experimental strains were evaluated,antagonistic effect of functional bacteria were detected,complex microbial community were constructed,and the plant growth promotion and disease resistance effects of microbial community on tobacco were evaluated.The results showed that rhizosphere bacteria LSNSY15-4 strain exhibited the best promoting effects on tobacco.Compared with control,the height,root length and fresh weight of tobacco treated with LSNSY15-4 increased by 22.45%,35.57% and 155.72%,respectively.Rhizosphere bacteria D showed great inhibitory effect on Ralstonia solanacearum,and its inhibitory zone diameter was 21.40 mm.Phylogenetic tree analysis proved that LSNSY15-4 belonged to Pantoea vagans,and antagonistic strain D was considered as Bacillus velezensis.On the basis of confirming the affinity between strain D and LSNSY15-4,strain D and LSNSY15-4 were mixed for 24 h at a volume ratio of 1:1 to obtain the complex microbial community.Compared with the blank control group,the plant height,leaf number and fresh weight of tobacco treated the complex microbial community increased by 10.21%,32.26% and 54.67%,respectively,and the complex microbial community could effectively prevent and control the incidence of tobacco bacterial wilt.The results provide a new way for the safety and effective control of tobacco soil borne diseases.