The fungal diversity associated with maize from emerging farms in the Eastern Cape, South Africa

Abstract

Maize is a staple food crop cultivated globally. In South Africa, the Eastern Cape contributes less than 1% to the overall production. The farming community in the Eastern Cape is largely comprised of small scale and emerging maize farms. Maize production in the province has previously been associated with mycotoxigenic fungi and their toxic metabolites. The Eastern Cape has recently been identified as a region to be developed into a large maize producer. However, there is a gap in the knowledge on the fungi associated with maize in the province. This prompted the present study in which we explored the fungal diversity and mycotoxins associated with maize from emerging maize farms in the Eastern Cape. The fungal diversity associated with post-harvest maize collected from the Eastern Cape was examined. This study resulted in the isolation of 481 fungal strains belonging to Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium and 15 other genera. Communities were found to be relatively diverse with strains identified to 84 species. Amongst these were several known mycotoxin producers. The most common species identified were Fusarium boothii, F. poae, F. temperatum, and Cladosporium cladosporioides. In addition, this study aimed to identify the fungal species and mycotoxins associated with maize ear rots collected from maize farms in the Eastern Cape. We observed Cladosporium, Diplodia, Fusarium and Gibberella ear rots. It was noted that ear rots are caused by a more diverse range of species than previously thought. The co-occurrence of mycotoxins associated with these species was also recorded. This survey is the first reporting a diverse range of fungal species from Eastern Cape produced maize that employed DNA sequences to make identifications. Additionally, this is the first study conducted in the Eastern Cape to consider all of these aspects together. This study creates an important baseline knowledge for future surveys that will focus on the impact fungal communities may have on the production of high-quality maize in the region, the diseases they may cause, and the mycotoxins they may produce.