Genetic Diversity of Aflatoxin-producing Aspergillus Flavus Isolated from Selected Groundnut Growing Agro-ecological Zones of Uganda

dc.contributor.authorAcur, Amos
dc.contributor.authorArias, Renée S.
dc.contributor.authorOdongo, Steven
dc.contributor.authorTuhaise, Samuel
dc.contributor.authorSsekandi, Joseph
dc.contributor.authorAdriko, John
dc.contributor.authorMuhanguzi, Dennis
dc.contributor.authorBuah, Stephen
dc.contributor.authorKiggundu, Andrew
dc.date.accessioned2021-10-29T14:44:52Z
dc.date.available2021-10-29T14:44:52Z
dc.date.issued2020-08-14
dc.description.abstractGroundnut pre- and post-harvest contamination is commonly caused by fungi from the Genus Aspergillus. Aspergillus flavus is the most important of these fungi. It belongs to section Flavi; a group consisting of aflatoxigenic (A. flavus, A. parasiticus and A. nomius) and non-aflatoxigenic (A. oryzae, A. sojae and A. tamarii) fungi. Aflatoxins are food-borne toxic secondary metabolites of Aspergillus species associated with severe hepatic carcinoma and children stuntedness. Despite the well-known public health significance of aflatoxicosis, there is a paucity of information about the prevalence, genetic diversity and population structure of A. flavus in different groundnut growing agroecological zones of Uganda. This cross-sectional study was therefore conducted to fill this knowledge gap. Results: The overall pre- and post-harvest groundnut contamination rates with A. flavus were 30.0 and 39.2% respectively. Pre- and post-harvest groundnut contamination rates with A. flavus across AEZs were; 2.5 and 50.0%; (West Nile), 55.0 and 35.0% (Lake Kyoga Basin) and 32.5 and 32.5% (Lake Victoria Basin) respectively. There was no significant difference (χ 2 = 2, p = 0.157) in overall pre- and post-harvest groundnut contamination rates with A. flavus and similarly no significant difference (χ 2 = 6, p = 0.199) was observed in the pre- and post-harvest contamination of groundnut with A. flavus across the three AEZs. The LKB had the highest incidence of aflatoxin-producing Aspergillus isolates while WN had no single Aspergillus isolate with aflatoxin-producing potential. Aspergillus isolates from the pre-harvest groundnut samples had insignificantly higher incidence of aflatoxin production (χ 2 = 2.667, p = 0.264) than those from the post-harvest groundnut samples. Overall, A. flavus isolates exhibited moderate level (92%, p = 0.02) of genetic diversity across the three AEZs and low level (8%, p = 0.05) of genetic diversity within the individual AEZs. There was a weak positive correlation (r = 0.1241, p = 0.045) between genetic distance and geographic distance among A. flavus populations in the LKB, suggesting that genetic differentiation in the LKB population might be associated to geographic distance. A very weak positive correlation existed between genetic variation and geographic location in the entire study area (r = 0.01, p = 0.471), LVB farming system (r = 0.0141, p = 0.412) and WN farming system (r = 0.02, p = 0.478). Hierarchical clustering using the unweighted pair group method with arithmetic means (UPGMA) revealed two main clusters of genetically similar A. flavus isolates. Conclusions: These findings provide evidence that genetic differentiation in A. flavus populations is independent of geographic distance. This information can be valuable in the development of a suitable biocontrol management strategy of aflatoxin-producing A. flavus.en_US
dc.identifier.issnhttps://bmcmicrobiol.biomedcentral.com/
dc.identifier.urihttp://hdl.handle.net/20.500.12280/2856
dc.language.isoenen_US
dc.publisherBMC Microbiologyen_US
dc.relation.ispartofseriesBMC Microbiology;20, Article number: 252 (2020)
dc.subjectMycotoxinsen_US
dc.subjectSecondary metabolitesen_US
dc.subjectAspergillus speciesen_US
dc.subjectAgro-ecological zoneen_US
dc.titleGenetic Diversity of Aflatoxin-producing Aspergillus Flavus Isolated from Selected Groundnut Growing Agro-ecological Zones of Ugandaen_US
dc.typeArticleen_US

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