Fusarium Species and Associated Fumonisin Contamination in Maize as Influenced by Sample Types in Eastern Ethiopia

Abstract

Fusarium species are the most toxigenic fungal pathogens responsible for various diseases in maize and other food grains. Fusarium infection in maize contaminates harvested grain with mycotoxins such as Fumonisins. Fumonisins contamination in maize can cause yield loss and health problems in humans and animals. The study aims to assess Fusarium species and fumonisin contamination in fresh harvested and three-month stored maize samples collected from five major maize growing districts of eastern Ethiopia, during the 2017/18 cropping season. Fusarium species were isolated and identified using direct plating technique, while Fumonisin concentration was analyzed by ELISA protocols. Higher numbers of Fusarium isolates were recorded in fresh harvested (2376 isolates) than in three-month stored maize samples (1897 isolates). The isolates were recorded in 97 and 90% of fresh harvested and three-month stored maize samples, with an average kernel contamination of 62 and 50%, respectively. A total of seven Fusarium species were identified from the samples. The most prevalent species was F. verticillioides in both samples, followed by F. proliferation and F. subgulitnans in fresh harvested and three-month stored samples, respectively. All fresh harvested and 92% of three-month stored maize samples were found fumonisin-positive (ranging from 105 to 5,460 )ig kg '). In all districts fumonisin concentration recorded in fresh harvested samples (2,509 j.ig kg-1) was higher than that of three-month stored maize samples (1,668 Hg kg-1). Prevalence of different Fusarium species could indicate the possibility of maize contamination by other mycotoxins. Therefore, further studies are needed considering different factors over different cropping years. Findings of the study could serve as foundation for any other study on Fusarium species and fumonisin contamination in maize in Ethiopia to design appropriate management strategies.