Esuola Catherine Oluwakemi, Ortega-Beltran Alejandro
Biotechnology Research Unit, National Horticultural Research Institute, Ibadan, Oyo-State, Nigeria.
Pathology and Mycotoxin Unit, International Institute of Tropical Agriculture, Ibadan, Oyo-State, Nigeria.
Front Fungal Biol. 2025 Mar 24;6:1563824. doi: 10.3389/ffunb.2025.1563824. eCollection 2025.
Onion bulbs are edible, nutritious vegetables and spices. In Nigeria, mass propagation of onion seedlings is limited due to infection of the onion bulbs by section , especially strains. Mycotoxin-producing strains are detrimental to public health. Hence, this study was undertaken to screen the locally sourced onion bulbs for fumonisin B (FB) [Multiplex A: (374 bp), (272 bp), (168 bp), and (479 bp) and Multiplex B: (452 bp), (238 bp), (173 bp), and (321 bp)] and ochratoxin A [OTA; (776 bp)] biosynthetic genes.
Thus, 100 onion bulbs were collected from four different local markets (Dugbe, Agbowo, Sasa, and Omi). The surface of each bulb was disinfected, and after incubation, isolates of were detected. isolates were cultured on potato dextrose agar. Genomic DNA was extracted from isolates of . Multiplex PCR confirmed the presence and absence of FB () and OTA () biosynthetic genes.
A total of 200 isolates of were isolated from the onion bulbs, and 22 (11%) isolates amplified at least two genes, while three (1.5%) amplified the gene. All isolates were positive for and . The highest/lowest percentage of the location/isolates of and was Agbowo/Omi with 32.0%/2.1% and Dugbe/Agbowo with 6.7%/2.3%, respectively. Hence, the use of multiplex PCR to detect FB and OTA biosynthetic genes in the isolated strains from the locally sourced onion bulbs will assist onion growers in the mass production of healthy onion seedlings with export potential and quality. Early detection of FB and OTA biosynthetic genes is important to predict possible mycotoxin-producing . section in onion bulbs.
洋葱鳞茎是可食用的营养蔬菜和调味品。在尼日利亚，由于洋葱鳞茎受镰刀菌属感染，特别是某些菌株感染，洋葱幼苗的大规模繁殖受到限制。产生霉菌毒素的菌株对公众健康有害。因此，本研究旨在筛选本地来源的洋葱鳞茎中伏马菌素B（FB）[多重PCR A：（374 bp）、（272 bp）、（168 bp）和（479 bp）以及多重PCR B：（452 bp）、（238 bp）、（173 bp）和（321 bp）]和赭曲霉毒素A [OTA；（776 bp）]生物合成基因。
从四个不同的当地市场（杜格贝、阿格博沃、萨萨和奥米）收集了100个洋葱鳞茎。对每个鳞茎的表面进行消毒，培养后检测镰刀菌属的分离株。将镰刀菌属分离株在马铃薯葡萄糖琼脂上培养。从镰刀菌属分离株中提取基因组DNA。多重PCR确认了FB（）和OTA（）生物合成基因的存在与否。
从洋葱鳞茎中总共分离出200株镰刀菌属分离株，22株（11%）分离株扩增出至少两个镰刀菌属基因，而3株（1.5%）扩增出赭曲霉毒素A基因。所有分离株的和检测均为阳性。镰刀菌属和赭曲霉毒素A的最高/最低位置/分离株百分比分别为阿格博沃/奥米，分别为32.0%/2.1%，以及杜格贝/阿格博沃，分别为6.7%/2.3%。因此，使用多重PCR检测从本地来源洋葱鳞茎中分离出的镰刀菌属菌株中的FB和OTA生物合成基因，将有助于洋葱种植者大规模生产具有出口潜力和品质的健康洋葱幼苗。早期检测FB和OTA生物合成基因对于预测洋葱鳞茎中可能产生霉菌毒素的镰刀菌属至关重要。
