河南农业科学2026，Vol.55Issue(5)：83-95,13.DOI:10.15933/j.cnki.1004-3268.2026.05.009
烟草疫霉拮抗菌株的筛选、鉴定及体外拮抗机制分析
Screening,Identification,and in Vitro Antagonistic Mechanism Analysis of Strains against Phytophthora nicotianae
摘要
Abstract
To screen strains with antagonistic activity against Phytophthora nicotianae and to develop microbial resources for the biological control of tobacco black shank,antagonistic strains were isolated using dilution plating and dual-culture assays.Dominant antagonistic strains were identified based on morphological characteristics,16S rRNA gene,and the sequences of 31 housekeeping genes.Their antimicrobial capacity was further evaluated via broad-spectrum inhibition assays and determination of antibacterial activity in sterile fermentation filtrate.The control efficacy of sterile fermentation filtrates against P.nicotianae was assessed by measuring lesion length on detached leaves.Whole-genome sequencing of the antagonistic strain was performed using next-generation sequencing technology,and the genomic data were analyzed with KEGG database and antiSMASH software.Active antimicrobial compounds were identified by ultra-performance liquid chromatography coupled with high-resolution mass spectrometry(UPLC-MS).Results indicated that a strain of Bacillus cereus YC5 with antagonistic activity against P.nicotianae was successfully isolated and screened.Dual-culture assays demonstrated that strain YC5 exhibited a 74.22％inhibition rate against P.nicotianae,along with antifungal activity against multiple plant pathogenic fungi including the causal agents of tobacco Fusarium wilt and wheat crown rot.In vitro leaf tests confirmed that the sterile fermentation filtrate of YC5 significantly suppressed lesion expansion,demonstrating remarkable antifungal efficacy.Genomic analysis revealed that YC5 possessed a genome size of 5 859 938 bp with 34.779％GC content.Among the 5 824 predicted genes,3 813 were annotated in the KEGG database.antiSMASH predicted 14 secondary metabolite biosynthetic gene clusters,and UPLC-MS identified various upregulated antimicrobial compounds.These findings demonstrated that YC5 exerted its biocontrol activity primarily through the production of diverse antimicrobial substances,which effectively suppressed the growth of P.nicotianae and other phytopathogens,thereby providing protective effects for plants.In summary,strain YC5 has the ability to synthesize multiple antibacterial compounds,and has antagonistic effects on Phytophthora nicotianae and various plant pathogenic fungi.关键词
烟草黑胫病/烟草疫霉/拮抗菌株/生物防治/蜡样芽胞杆菌/基因组测序/代谢组学Key words
Tobacco black shank/Phytophthora nicotianae/Antagonistic strain/Biological control/Bacillus cereus/Genome sequencing/Metabolnomics分类
农业科技引用本文复制引用
张志高,王闯,尹冬,黄旭民,章慧芬,许兴辉,何文卿,张红..烟草疫霉拮抗菌株的筛选、鉴定及体外拮抗机制分析[J].河南农业科学,2026,55(5):83-95,13.基金项目
河南省科技攻关项目(252102410005) （252102410005）
中国烟草总公司江西省公司科技计划项目(202301006) （202301006）
