Long Meimei, Wang Qiuyue, Li Shanshan, Liu Changyun, Chen Shan, Yang Yanhui, Ma Haoyue, Guo Lulu, Fan Guangjin, Sun Xianchao, Ma Guanhua
Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, China.
Institute of Characteristic Crops, Chongqing Academy of Agricultural Sciences, Chongqing, China.
Pest Manag Sci. 2023 Oct;79(10):3871-3882. doi: 10.1002/ps.7591. Epub 2023 Jun 15.
Pepper blight, caused by Phytophthora capsici, is a destructive soilborne disease, which poses a serious threat to pepper, Capsicum annuum L., production. Chemical fungicides, which mainly are used to control pepper blight, have a negative effect on the environment, rendering biological control as a promising alternative to maintain the balance between ecology and pest management. The purpose of this study was to screen the biocontrol bacteria, reduce the dosage of fungicides and increase the stability of biocontrol bacteria, and to find the mixing ratio of biocontrol bacteria and fungicides giving the best control effect.
We isolated actinomycetes strains from the soil surrounding the roots of healthy pepper plants amongst field-grown plants infected with P. capsici. Of these, Streptomyces albus XJC2-1 showed a strong inhibition effect on the growth of P. capsici, with an inhibition rate of ≤85%. XJC2-1 effectively inhibited the formation of sporangium and release of zoospores of P. capsici as well as directly destroyed its hyphae, to achieve the inhibitory effect. Transcriptomic profiling of pepper leaves, postirrigation of plants with the XJC2-1 fermentation broth, revealed upregulation of genes related to the photosynthesis pathway in pepper. Furthermore, XJC2-1 treatment improved the net photosynthetic rate and intercellular CO concentration, thereby improving the pepper plant's resistance to pathogens. The combination of XJC2-1 with the fungicide dimethomorph (8 μg mL ) displayed strong synergism in inhibition of P. capsici infection, with a control efficiency as high as 75.16%, thus providing a basis for its application in the field.
Our study demonstrated that S. albus XJC2-1 inhibited Phytophthora pathogens from infecting pepper plants and enhanced plant host resistance. The combination of XJC2-1 and dimethomorph displayed a more stable and stronger control effect on pepper blight, showing potential for the future application of XJC2-1 in the field of biological control. © 2023 Society of Chemical Industry.
由辣椒疫霉引起的辣椒疫病是一种具有毁灭性的土传病害，对辣椒（Capsicum annuum L.）生产构成严重威胁。主要用于防治辣椒疫病的化学杀菌剂对环境有负面影响，这使得生物防治成为维持生态与害虫管理平衡的一种有前景的替代方法。本研究的目的是筛选生防细菌，降低杀菌剂用量并提高生防细菌的稳定性，以及找出能产生最佳防治效果的生防细菌与杀菌剂的混合比例。
我们从田间感染辣椒疫霉的植株中健康辣椒植株根围土壤中分离出放线菌菌株。其中，白色链霉菌XJC2-1对辣椒疫霉的生长表现出强烈抑制作用，抑制率≤85%。XJC2-1有效抑制了辣椒疫霉孢子囊的形成和游动孢子的释放，并直接破坏其菌丝，从而实现抑制效果。用XJC2-1发酵液浇灌植株后，对辣椒叶片进行转录组分析，结果显示辣椒中与光合作用途径相关的基因上调。此外，XJC2-1处理提高了净光合速率和细胞间CO浓度，从而提高了辣椒植株对病原体的抗性。XJC2-1与杀菌剂烯酰吗啉（8 μg mL）组合在抑制辣椒疫霉感染方面表现出强烈的协同作用，防治效果高达75.16%，从而为其在田间应用提供了依据。
我们的研究表明，白色链霉菌XJC2-1可抑制疫霉病原体感染辣椒植株并增强植物宿主抗性。XJC2-1与烯酰吗啉组合对辣椒疫病表现出更稳定、更强的防治效果，显示出XJC2-1在生物防治领域未来应用的潜力。© 2023化学工业协会。
