| 摘要: |
| 【目的】明确吉林白城和内蒙古开鲁辣椒白皮病病原，并从辣椒根际土壤中筛选对该病原菌具有良好防效的生防菌，为辣椒白皮病的诊断和绿色防控提供参考。【方法】从吉林白城和内蒙古开鲁辣椒产区，采集表现“白皮”症状的辣椒果实及其根际土壤样品，采用组织分离法分离纯化病原菌，果实接种法验证分离病原菌的致病性，通过形态学结合ITS-ACT-TUB-CHS-GAPDH-HIS3多基因联合法对分离的致病菌进行鉴定。利用逐级稀释法分离辣椒根际土壤样品中的放线菌，用离体结合活体测定法筛选对分离病原菌有显著拮抗活性的生防菌，并采用形态学、培养特性和分子序列相结合的方法对筛选的生防菌株进行鉴定。【结果】从吉林白城和内蒙古开鲁辣椒样品中分离得到25株真菌，其中有6株真菌在致病性测定中表现出典型的白皮病症状，分别为LJ1、LJ2、LJ3、LJ4、LJ5和KLLJ9，形态学结合多基因联合确定分离的病原菌均为斯高维尔炭疽菌（Colletotrichum scovillei）。以斯高维尔炭疽菌LJ1为供试靶标菌，从辣椒根际土壤中分离到1株拮抗放线菌SLJ2-2，其能有效抑制斯高维尔炭疽菌LJ1的感染和扩展，喷施3次SLJ2-2发酵上清液后对斯高维尔炭疽菌LJ1的抑制率达到95.53%，结合形态学、培养特性和分子生物学方法将SLJ2-2鉴定为微黄白链霉菌（Streptomyces albidoflavus）。【结论】吉林白城和内蒙古开鲁地区辣椒白皮病主要由斯高维尔炭疽菌侵染引起，从辣椒根际土壤中筛选出的微黄白链霉菌能有效抑制该病原菌的感染及其在辣椒上的扩展。 |
| 关键词: 辣椒白皮病 病原鉴定 生物防治 斯高维尔炭疽菌 微白黄链霉菌 |
| DOI： |
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| 基金项目:内蒙古自治区科技重大专项（2021SZD0040）；内蒙古自治区高教项目（NJZY21458，NJZY22521）；“科技兴蒙”行动重点专项（211） |
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| Isolation of pathogens causing chilli white skin disease in Baicheng,Jilin and Kailu,Inner Mongolia and screening of effective biocontrol agent |
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SUN Pingping,FAN Bowen,U Chongyi,et al
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| Abstract: |
| 【Objective】This study identified the pathogen causing chilli white skin in Baicheng, Jilin and Kailu,Inner Mongolia，and screened the biocontrol agent from rhizosphere of chilli plants with high control efficiency to provide information for the identification and control of chilli white skin disease.【Method】Diseased chilli fruits with symptoms of white skin and rhizosphere soil were collected from Baicheng,Jilin and Kailu,Inner Mongolia.Tissue isolation method was used to isolate the fungi,and the pathogenicity of isolated strains was verified by inoculation method before the pathogenic strains were identified by morphologic characters combined with ITS-ACT-TUB-CHS-GAPDH-HIS3 multigene method.Actinomycetes were isolated from rhizosphere of chilli plants by serial dilution method,and biocontrol agents with significant antagonistic activity against the fungi were screened by in vitro and in vivo assay.The isolated biocontrol agents were identified by morphologic characters combined with molecular methods.【Result】A total of 25 fungal isolates were isolated from chilli samples,and 6 of them (namely LJ1,LJ2,LJ3,LJ4,LJ5 and KLLJ9) showed typical white skin symptoms in the pathogenicity test.All of these 6 strains were identified as Colletotrichum scovillei by morphologic characters together with multigene method. The strain SLJ2-2 isolated from rhizosphere of chilli showed significant inhibitory activity against C. scovillei LJ1 and the disease diameter of C. scovillei LJ1 on chilli fruits was reduced by 95.53% after spraying SLJ2-2 by 3 times.The morphologic and cultural characters together with molecular identification indicated that SLJ2-2 was Streptomyces albidoflavus.【Conclusion】C. scovillei was the main cause of chilli white skin in Baicheng,Jilin and Kailu,Inner Mongolia and S. albidoflavus SLJ2-2 isolated from rhizosphere could effectively inhibit C. scovillei. |
| Key words: chilli white skin pathogen identification biological control Colletotrichum scovillei Streptomyces albidoflavus |
