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ORIGINAL RESEARCH article
Front. Fungal Biol.
Sec. Fungal Secondary Metabolites and Mycotoxins
Volume 6 - 2025 | doi: 10.3389/ffunb.2025.1563824
This article is part of the Research Topic Women in Fungal Secondary Metabolites and Mycotoxins 2024 View all articles
Journal: Frontiers in Fungal Biology Type: Original Research Fumonisin and ochratoxin-producing Aspergillus section Nigri strains associated with onion (Allium cepa L.) bulbs commercialized in markets in South West Nigeria
Provisionally accepted- 1 National Horticultural Research Institute (NIHORT), Ibadan, Nigeria
- 2 International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
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 Aspergillus niger strains. Mycotoxinproducing A. niger strains are detrimental to public health. Hence, this study was undertaken to screen the locally sourced onions bulbs for fumonisin (FB2) (Multiplex A: fum6 (374 bp), fum8 (272 bp), fum13 (168 bp), and fum19 (479 bp) and Multiplex B: fum1 (452 bp), fum7 (238 bp), fum3 (173 bp), and fum14 (321 bp) and ochratoxin (OTA) pks15ks (766 bp) A. niger biosynthetic genes. One hundred onion bulbs were collected from four different local markets (Dugbe, Agbowo, Sasa, and Omi). Each of the onion bulb's surfaces was disinfected, and after incubation, isolates of A. niger were detected. A. niger isolated were cultured on potato dextrose agar.Genomic DNA was extracted from isolates of A. niger. Multiplex PCR confirmed the presence and absence of FB2 (fum) and OTA (pks15ks) biosynthetic genes. A total of 200 isolates of A. niger were isolated from the onion bulbs. Twenty-two (11%) isolates amplified at least two fum genes while three (1.5%) amplified the pks15ks gene. All the isolates are positive to fum 1 and fum 19. The highest/lowest percentage of the location/isolates of fum and pks15ks was Agbowo/Dugbe, 32.0%/16.7%, and Dugbe/Agbowo, 6.7%/3.3% respectively. Hence, the use of multiplex PCR to detect FB2 and OTA biosynthesis genes in the isolated A. niger strains from the locally sourced onion bulbs will assist onion growers in the mass production of healthy onion seedlings with export potentials and qualities. The early detection of FB2 and OTA biosynthesis genes is important to predict possible mycotoxin-producing A. niger strains in the onion bulbs.
Keywords: Mycotoxigenic Aspergillus niger, fumonisin B2 (FB2), ochratoxin (OTA), Food security, Multiplex PCR (polymerase chain reaction), Post-harvest loss, Onion bulbs
Received: 20 Jan 2025; Accepted: 26 Feb 2025.
Copyright: © 2025 Esuola and Ortega-Beltran. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Catherine Oluwakemi Esuola, National Horticultural Research Institute (NIHORT), Ibadan, Nigeria
Alejandro Ortega-Beltran, International Institute of Tropical Agriculture (IITA), Ibadan, PMB 5320, Nigeria
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