ELKasaby Aya I, Ghoneem Khalid M, Shabana Yasser M
Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt.
Seed Pathology Research Department, Plant Pathology Research Institute, Agricultural Research Center, Giza, 12619, Egypt.
Sci Rep. 2025 Jul 30;15(1):27864. doi: 10.1038/s41598-025-10036-8.
Onion white rot, caused by Stromatinia cepivora, is a major soil-borne fungal disease that severely affects onion production. This study introduces a novel endophytic bacterium, Achromobacter xylosoxidans AX77 16S, isolated from healthy onion seeds, as a potential biocontrol agent and growth promoter. Out of 78 bacterial isolates screened, AX77 16S showed the strongest antifungal activity, inhibiting pathogen growth by 50% in dual culture assays. Its application significantly enhanced seed germination (up to 82%) and improved shoot and root development, increasing vigor indices by over 100% compared to untreated controls. The strain was identified by biochemical and molecular techniques and registered in GenBank (ON679518). GC-MS analysis revealed ten bioactive compounds in the bacterial filtrate, while scanning electron microscopy confirmed its damaging effects on fungal structures. Additionally, AX77 16S was formulated into a granular product that remained viable for up to one year. This study presents a promising, sustainable, and cost-effective alternative to chemical fungicides for managing onion white rot and promoting crop growth.
由洋葱核盘菌引起的洋葱白腐病是一种严重影响洋葱生产的主要土传真菌病害。本研究介绍了一种从健康洋葱种子中分离出的新型内生细菌——木糖氧化无色杆菌AX77 16S，它可作为一种潜在的生物防治剂和生长促进剂。在筛选的78株细菌分离物中，AX77 16S表现出最强的抗真菌活性，在双培养试验中抑制病原菌生长达50%。其应用显著提高了种子发芽率（高达82%），并改善了地上部和根部的发育，与未处理的对照相比，活力指数提高了100%以上。该菌株通过生化和分子技术进行了鉴定，并在GenBank（ON679518）中注册。气相色谱-质谱联用分析揭示了细菌滤液中的十种生物活性化合物，而扫描电子显微镜证实了其对真菌结构的破坏作用。此外，AX77 16S被制成颗粒产品，可存活长达一年。本研究为防治洋葱白腐病和促进作物生长提供了一种有前景、可持续且经济高效的替代化学杀菌剂的方法。
