烟草赤星病拮抗菌WN1的鉴定与生防效果研究

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中图分类号：S435.72 文献标识码：A文章编号：1007-5119（2026）01-0079-09

Abstract：Toinvestigatetheiologicalcontroloftobaccobownspot（BS），culturablebacterialstrainswereisolatedfroobac leavesandsubsequentlyscreenedforeffectiveantagonisticstrainsagainstAlterariaalterata.Theplatefaceofftestdemostrated thatstrain WN1 exhibitedaninhibitionrate of 84.62% onthehyphal growth ofA.alternata.Furthermore， the fermentation liquid derived from WN1 significantly inhibited conidial germination of A alternata. The broad-spectrum antibacterial activity assay revealedthatWN1alsopossessedapronouncedinhibitoryefectonseveral important plantpathogens，including Valsmal， Coletotrichum gloeosporioides， Magnaporthe oryzae， Fusarium graminearum， Phytophthora infestans，and P parasitica. Morphological identification，along withhysiologicalandbiochemicalanalyses，aswellasphylogeneticanalysis，cofidthat strainWN1belongs to Bacilusmethylotrophicus.Microscopic observationrevealed that the WN-GFPtaggedstrain wascapableof colonizingboth the surfaceand intermal tisses of tobacco leaves.The colonization numbers of WN1 were maintained at 103CFU/g in thetobacco leavessprayedwith6Otimes dilutionofWNfermentation liqud，monitoredat40days post-ioculation.Testrain WN1inducedandsignificantlyincreasedthactivitiesofdefense-relatedenzmesintobaccosuchasproxidase （OD），atalase （CAT），polyphenloxidase（PPO），andphenylalanineammonia-lyase（PAL）.Thefieldeficacyevaluationdemonstratedtatthe application of WN1 strain fermentation broth at a rate of 6kg/hm2 resulted in a control efficacy of 85.29% against TBS. Considering boththelaboratoryandfieldinhbitoryefectsofWN1onTBS，WN1demonstratessignificantpotentialasapromisingbiocontrol agent for the management of TBS.

Keywords： Bacillus; tobacco brown spot; antagonism; colonization; biological control

烟草NicotianatabacumL.是我国主要的经济作物之一，2023年烟叶年产量达到229.67万t，年产值约为600亿元，在国民经济中占据着重要地位。（剩余16576字）