*2.3.1. Genetic modification*

Genetically modified crops are plants of which the DNA has been altered through the introduction of a foreign gene to express a trait not inherent to the modified plant. Three transgene-mediated strategies have been proposed for the management of mycotoxigenic fungi and mycotoxins in maize [48]. These include (1) the reduction of fungal infection, (2) the degradation of mycotoxins and (3) interfering with the mycotoxin biosynthetic pathway. To reduce infection by the fungus, the incorporation of antifungal and/or resistance genes, as well as the overexpression of defence-related genes, is required. Catabolic enzymes from microbes have been used to detoxify certain mycotoxins both *in vitro* and *in situ*, before they accumulate in the plant [49–51]. Fumonisin esterase and amine oxidase genes encoding FUM-degrading enzymes have been identified in *Exophiala spinifera* de Hoog and Hasse [48]. None of these genes have, however, been successfully introduced into maize. Maize plants have, however, been genetically engineered to interfere with the biosynthesis of AF and TCT [52, 53]. The best-known example of using genetically modified maize for reducing FER and FUM contamination of grain is Bt maize [54, 55]. This is due to the close association between kernel damage by insects and infection by *F. verticillioides* [56]. Bt maize plants that prevent insect damage, therefore, also reduce FUM contamination of maize grain. Genetically modified maize is not authorised in all countries and, consequently, conventional breeding efforts are still commonly used.

#### *2.3.2. Mutation breeding*

Exposure of seeds or other heritable materials to chemicals or radiation with the purpose to induce DNA changes (mutations) is known as mutation breeding. Nuclear technology for crop improvement makes use of ionising radiation, which causes induced mutations with a high mutation frequency in plants [57]. These mutations might be beneficial and alter physiological characters of plants, including plant height, ear height and improved root architecture [58, 59]. The radiation of seeds may also cause genetic variability that enables breeders to select new genotypes with improved grain yield and quality [60]. Mutation breeding has been successfully used to generate genetic variation in cereal crops, including maize, for a number of aspects including enhanced yield and productivity, altered ear length, drought tolerance and enhanced stem structure [61–63]. It can thus potentially provide an attractive means for generating tolerance to mycotoxigenic fungi and their mycotoxins.
