中文摘要：

【目的】对采自陕西、甘肃和河南省的51个土壤样品中的细菌进行分离纯化，筛选番茄灰霉菌的拮抗生防菌株，并研究其防治效果和最优发酵条件。【方法】分别以平板对峙法和牛津杯法测定所分离菌株及其发酵滤液对番茄灰霉菌的抑菌作用，筛选出抑菌作用显著的菌株，测定其离体和温室防治效果，并通过正交试验对防治效果明显且稳定的生防菌株的发酵条件进行优化，最后进行i6SrDNA序列分析，对筛选菌株进行初步鉴定。【结果】经分离纯化得到533株细菌菌株，其中18BS-12的抑菌活性最好，离体和温室防治效果分别为82.37％和75.61％。对菌株18BS-12发酵培养基（NA培养基）进行正交试验优化，得到最佳发酵培养基配方（质量分数）为玉米粉2.0％，牛肉膏1.5％，FeSO4 0.015％。发酵滤液抑菌活性最强的发酵条件为：在250mL三角瓶中，将种子液按3％的体积比接种到50mL培养基中，初始pH7.0，温度32℃，转速180r／min，发酵时间5d。菌株18B-12的发酵滤液活性物质在高温、碱性条件和紫外光照射下较稳定。通过对其16SrDNA序列的分析比对，初步将其鉴定为唐菖蒲伯克霍尔德菌（Burkholderiagladioli）。【结论】菌株18BS-12是1株对番茄灰霉病具有防治潜力的生防菌株。

英文摘要：

[Objective] Bacterial strains were isolated from 51 soil samples from Shaanxi, Henan and Gansu for screening the antagonism strains of tomato grey mold. Their control effect and optimal fermentation conditions were also studied. [Method] Using Botrytis cinerea as the target,inhibitory effect of isola ted strains was detected through plate confrontation and Oxford plate method. The control effects of isolated strains with high antibacterial activity were determined in vitro and in greenhouse. Then, fermentation conditions of strains with significant and stable control effect were orthogonally optimized. At last, the selected bacterial strain was identified through 16S rDNA sequences analysis. [Result] Bacterial strain 18BS-12 was screened with highest antibacterial activity among 533 isolated strains. The control effects of strain 18BS-12 against tomato gray mold in vitro and in greenhouse were 82.37% and 75.61% ,respectively. Orthogonal test obtained the optimal medium （NA） .corn meal 2.0% ,beef extract 1.50//oo and FeSO4 0. 015%. The optimal fermentation conditions for producing antimicrobial substance were.250 mL flask,volume ratio of seed 1 r/min, and perature, a quid 30%, fermentation medium 50 mL, initial pH 7. 0, temperature 32 ℃, rotation speed 180 fermentation time 5 d. The active substance of fermentation filtrate was stable under high temkaline conditions and UV. Based on 16S rDNA sequences comparison and analysis, 18BS-12 strain was initially identified as Burkholderia gladioli. [Conclusion] Strain 18BS-12 is a potential biocontrol strain against B. cinerea.