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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #347304
Research Project: Improved Environmental and Crop Safety by Modification of the Aspergillus flavus Population Structure

Location: Pest Management and Biocontrol Research

Title: Prevalence of aflatoxin contamination in maize and groundnut in Ghana: Population structure, distribution, and toxigenicity of the causal agents

Author
item AGBETIAMEH, D - International Institute Of Tropical Agriculture (IITA)
item ORTEGA-BELTRAN, A - International Institute Of Tropical Agriculture (IITA)
item AWUAH, R - Kwame Nkrumah University Of Science And Technology
item ATEHNKENG, J - International Institute Of Tropical Agriculture (IITA)
item Cotty, Peter
item BANDYOPADHYAY, R - International Institute Of Tropical Agriculture (IITA)

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2017
Publication Date: 4/1/2018
Citation: Agbetiameh, D., Ortega-Beltran, A., Awuah, R.T., Atehnkeng, J., Cotty, P.J., Bandyopadhyay, R. 2018. Prevalance of aflatoxin contamination in maize and groundnut in Ghana: Population structure, distribution, and toxigenicity of the causal agents. Plant Disease. 102(4):764-772.

Interpretive Summary: Aflatoxins are toxic fungal metabolites that impair the immune system and cause cancer in humans. These poisons are a serious health concern in Ghana which consumes large quantities of maize in the form of the national dish Kenkey. Aflatoxins are produced by a diverse group of fungi. In order to develop management tools for limiting contamination, it is necessary to identify the fungi that cause the majority of aflatoxin contamination and to determine the distribution of contamination. Thirtyfive percent of 509 crop samples from Ghana contained aflatoxins. The most common aflatoxin producer among over 5,000 fungi examined from crop samples was the L morphotype of A. flavus which composed over 93%. Two high aflatoxin-producing fungi were also detected, A. parasiticus and S morphotype fungi. During the course of the work, areas with severe contamination were determined and fungi of potential use as biological control agents were identified. The results suggest that biocontrol is a viable option for future mitigation of contamination.

Technical Abstract: Aflatoxin contamination in maize and groundnut is perennial in Ghana with substantial health and economic burden on the population. The present study examined for the first time the prevalence of aflatoxin contamination in maize and groundnut in major producing regions across three agroecological zones (AEZ) in Ghana. Furthermore, the distribution and aflatoxin-producing potential of Aspergillus species associated with both crops were studied. Out of 509 samples (326 of maize and 183 of groundnut), with 35% had detectable levels of aflatoxins. Over 15% maize and 11% groundnut samples exceeded the aflatoxin threshold limits set by the Ghana Standards Authority, of 15 ppb and 20 ppb, respectively. Mycoflora analyses revealed various species and morphotypes within the Aspergillus section Flavi. A total of 5,083 isolates were recovered from both crops. The L morphotype of Aspergillus flavus dominated communities with 93.3% of the population, followed by Aspergillus spp. with S morphotype (6%), A. tamarii (0.4%), and A. parasiticus (0.3%). Within the L morphotype, the proportion of toxigenic members was significantly (P < 0.05) higher than that of atoxigenic members across AEZ. Observed and potential aflatoxin concentrations indicate that on-field aflatoxin management strategies need to be implemented throughout Ghana. The recovered atoxigenic L morphotype fungi are genetic resources that can be employed as biocontrol agents to limit aflatoxin contamination of maize and groundnut in Ghana.