Plants suffer from many diseases which are caused by various microbes like bacteria, fungi__ampersandsignnbsp; virus etc. Fungi of the genus Fusarium, widely distributed saprophyte, are extremely pathogenic to plants causing damage to plants by various vascular wilts, collar rot of seedlings, rot of tubers, bulbs and corms etc. Most of the diversity studies have been done on pathogenic strains of Fusarium sps which are split into divisions called host specific formae speciales (abbreviated f.sp.) .Many Fusarium sps produce harmful secondary metabolites called mycotoxins like zearalenones, trichothecenes, fumonisins etc. They reproduce by forming spores viz. microconidia, macroconidia and chlamydospores. Genetic variation studies among these can be performed by various methods using different types of molecular markers. These studies have characterised Fusarium sps. in different plants all over the world which can be exploited for developing biocontrol agents for resistance breeding. This would be an environment friendly and economical viable approach to control fungal plant diseases as compared to chemical fungicides.