Cultural and molecular identification of fungal genera and species occurring in maize : Fungi genera and species found in maize.

Abstract

Mycotoxins contribute to a substantial loss of global maize grain yields in terms of tonnes. However, in sub-Saharan Africa, screening of mycotoxin-producing fungi predominantly relies on culture-based methods, which are both time-consuming and labour-intensive. This study examined the major fungal species responsible for aflatoxin production in major maize-producing regions of Kenya using molecular techniques. Maize samples were collected from Kilifi, Makueni, and Kisumu counties. For fungal isolation followed by molecular identification targeting the internal transcribed spacer region (ITS) for Fusarium and calmodulin (CaM) genes for Aspergillus, Penicillium, and Trichoderma, this was followed by basic local alignment search tool (BLAST) analysis. The study revealed 14 fungal species belonging to four genera namely Aspergillus, Penicillium, Fusarium, and Trichoderma. Kisumu County had the highest diversity of fungal species, representing 47.8% of the total identified. Within Kisumu, Penicillium species were the most prevalent, with an incidence rate of 72.9%. In contrast, Aspergillus species were most common in Kilifi County (54.5% incidence). The application of DNA barcoding techniques significantly enhanced the precision of identifying aflatoxin-producing fungi compared to conventional identification methods. This study confirms the presence of multiple fungal species responsible for aflatoxin production in Kenya's maize-growing regions.