Preface

*Fusarium* is a fungal genus belonging to phylum Ascomycota, subphylum Pezizomycotina, class Sordariomycetes, order Hypocreales, and family Nectriaceae. It is a large cosmopolitan genus of imperfect fungi with an estimated 1500 species. As plant pathogens, they cause root and stem rot, vascular wilt, and/or fruit rot in several economic crop species. *Fusarium* is one of the most important mycotoxigenic fungal genera in food and feed. However, they contain non-pathogenic strains that can colonize plant roots with an equal measure of pathogenic strains. The pathogenic strains are classified into host-specific forms (*formae speciales*) based on their host ranges, and further subdivided into pathogenic races according to their abilities to infect plant cultivars. Fumonisins, zearalenone, deoxynivalenol, and additional trichothecenes are well-known *Fusarium* mycotoxins. Though *Fusarium* research has improved our understanding of this group of fungi over the past decades, many traits of its biology still need to be addressed. Among *Fusarium* diseases, *Fusarium* wilts is a major problem all over the world. *Fusarium oxysporum, F. solani, F. fujikuroi*, and *F. graminearum* are the representative species known as plant-pathogenic *Fusarium*. Although *Fusarium* spp. use multiple infection strategies, these fungi are hemibiotrophs capable of transitioning from biotrophic to necrotrophic phases depending on environmental conditions. Since *Fusarium* is predominantly a soil-borne pathogen that survives for a long time because it is resistant to chlamydospores in soil, management of *Fusarium* diseases remains a challenge. This book provides an overview of recent research on *Fusarium* species in the fields of metabolites, pathogenicity, plant-pathogen interactions, and management strategies in agricultural practices.

I hope that this book will help a wide range of readers to update their knowledge of *Fusarium*. I would like to thank IntechOpen for inviting me to be the book editor. Special thanks go to Author Service Managers Jasna Bozic and Andrea Tomurad for their help and cooperation during the editing process.

## **Seyed Mahyar Mirmajlessi**

Faculty of Bioscience Engineering, Ghent University (Gent), Ghent, Belgium

Section 1
