番茄采后寄生菌的分离鉴定及(E)-2-己烯醛抑菌活性研究

摘要

There were many diseases of tomato during postharvest storage and transportation,which seriously affect the quality of tomato.Because of low toxicity and high efficiency,biological control had been used as a new way to control postharvest diseases,became research hotspot.The paper mainly focused on the isolation and purification of the parasitic bacteria on the surface of the mature tomato,the bacterial strains were identified by morphological characteristics,physi-ological and biochemical characteristics,rDNA-ITS sequence analysis and phylogenetic analysis.Antibacterial activity of different concentrations of (E)-2-Hexenal against the bacterial strains were analysed.18 S rDNA genes were amplified by using universal fungal primers,PCR products (about 500 bp) were obtained.After sequencing,the bacterial strains were determined to be Penicillium cyclopium by blasting in NCBI database.According to the growth curve of Penicillium cyclopium,which can be learned that the biomass reached the maximum around 60-72h,the optimum temperature was 25-30 ℃,the optimum pH was 5.0.The antibacterial results showed (E)-2-Hexenal treatment was significantly effec-tives against mycelial growth of Penicillium cyclopium,the MIC was 160 μl/L in growth inhibition assays.%番茄采后储藏、运输中遭受的病害有很多,严重影响了番茄的品质.生物防治因低毒、高效,已作为控制采后病害的新途径,成为研究热点.本文主要对采后成熟番茄表面寄生菌进行分离纯化,通过形态特征、生理生化特性、rDNA-ITS序列分析以及系统发育分析对该菌株进行鉴定,并通过不同浓度(E)-2-己烯醛对该菌种进行抑菌分析.采用真菌通用引物扩增18S rDNA基因,得到PCR产物(约500 bp).测序后,NCBI数据库比对可知,确定其为圆弧青霉菌(Penicillium cyclopium).根据圆弧青霉的生长曲线可知,生长60-72 h,其生物量达到最大,其最适温度为25-30 ℃,最适pH为5.0.抑菌结果显示,(E)-2-己烯醛对圆弧青霉的菌丝生长有较好的抑制作用,对菌丝生长的最低抑菌浓度(MIC)为160 μL/L.