Fusarium species are soil borne vascular wilt pathogens, which are among the most important phytopathogenic and toxigenic fungi. They are filamentous and belong to the Class Ascomycetes and Family Hypocreaceae. Fusarium species typically produce macroconidia and microconidia, as well as mycelia and chlamydospores that serve as propagules in infecting host plants. The life cycle can be divided into dormant, parasitic and saprophytic stages. Most species are harmless saprobes; some species are parasitic, with some producing mycotoxins on plants. The pathogenic strains have high level of host specificity which has led to the development of the "formae specialis" concept. Each formae specialis can be further sub divided into races, on the basis of virulence in a set of differential cultivars within the same plant species. Fusarium wilt is a major concern in agriculture as it causes great economical losses in a wide variety of crops. The symptoms of Fusarium wilt range from stunted growth, yellowing andwilting of the leaves, reddish discolouration of the xylem vessels (visible inside the stem as lines or dots in cross section) and white, pink or orange fungal growth on the outside of affected stems (particularly in wet conditions), to root or stem decay.There is remarkably little knowledge available about the molecular mechanism and/or pathogenicity genes required by Fusarium species to cause disease and how hosts combat or tolerate the pathogen. The genomes of some Fusarium species have been sequencedand comparative genomic analyses have shown that pathogenic Fusarium species consist of a larger number of proteins in the pathogenicity related protein families such as transcription factors, hydrolytic enzymes, and transmembrane transporters which playsignificant roles in pathogenicity, compared to non pathogenic species. In general, the disease is difficult to control, as physical,chemical and cultural methods of control are not only ineffective but also expensive.The best method of control is breeding for resistant cultivars. Also, rhizosphere fungi such as Trichoderma harzianum, T. asperellum, T. koningii, Penicillium spp. and Streptomyces griseoviridis have been used to control the disease. This present reviewgives a general overview of some common Fusarium wilts.
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