Abstract: In order to screen out highly effective antifungal bacterium,which can be well colonized in the rhizosphere,root and leaf of tomato and has good control effect on tomato gray mold,the methods of plate screening,field screening,rifampicin resistance marker,morphological identification,physiological and biochemical identification,16S rRNA,gyrA and gyrB identification were used to screen and study the colonization characteristics and taxonomic status of highly efficient antifungal bacteria against Botrytis cinerea.The results showed that among 58 strains,strain ZSY-1 had more significantly antifungal activity against B.cinerea than other strains and had more than 75% antifungal activity against B.cinerea in indoor and field trials.Although the colonization characteristics of strain FG-6 in tomato rhizosphere (1.76×10⁶cfu/g),root system(1.54×10⁶cfu/g)and leaf(0.87×10⁶cfu/g) were significantly better than strain ZSY-1(rhizosphere:1.67×10⁶cfu/g;root system:1.46×10⁶cfu/g;leaf:0.64×10⁶cfu/g),but its field control effect was only about 30%,which was significantly lower than strain ZSY-1. Strain ZSY-1 was identified as Bacillus velezensis based on morphology,physiological and biochemical characteristics,16S rRNA,gyrA,and gyrB genes.The above results determined that strain ZSY-1 might be an excellent candidate strain against B.cinerea for the development of biological agents.

Key words: Endophytic bacteria, Botrytis cinerea, Colonization characteristics, Filed efficacy, Classification and identification

摘要： 为筛选出既可在番茄根际、根部、叶片良好定殖，又对番茄灰霉病具有较好防治效果的高效拮抗细菌，采用平板筛选、田间筛选、利福平抗性标记、形态鉴定、生理生化鉴定及16S rRNA、gyrA基因、gyrB基因鉴定相结合的方法对番茄灰霉病高效内生拮抗细菌进行筛选，并对其进行定殖特性测定和分类地位研究。结果表明，58株细菌中菌株ZSY-1抑菌活性较优，在室内和田间试验中对番茄灰霉病菌均可保持75%以上的抑菌效果；虽然菌株FG-6在番茄根际、根系、叶片中的定殖特性（菌落数分别为1.76×10⁶、1.54×10⁶、0.87×10⁶ cfu/g）明显优于菌株ZSY-1（菌落数分别为1.67×10⁶、1.46×10⁶、0.64×10⁶ cfu/g），但其田间防效较差，仅约30%，明显低于菌株ZSY-1；利用形态学、生理生化鉴定及16S rRNA、gyrA基因、gyrB基因鉴定，将菌株ZSY-1鉴定为贝莱斯芽孢杆菌（Bacillus velezensis）。上述结果表明，ZSY-1可作为番茄灰霉病防治菌剂和菌肥开发的优良候选菌株。

关键词: 内生细菌, 番茄灰霉病菌, 定殖特性, 田间防效, 分类鉴定