Fusarium graminearum Inoculation on Wheat Head

Background

Fusarium graminearum is a destructing fungal pathogen which causes globally serious Fusarium head blight (FHB) disease on cereal crops. In recent years, the incidence of FHB increased with the global climate change and changes in farming practices. Additionally, F. graminearum produces several mycotoxins including trichothecene mycotoxin deoxynivalenol (DON), which threatens the health of humans and animals (Tanaka et al., 1988; Windels, 2000; Su et al., 2018). Up to date, the most effective tools to control FHB are derived from the studies on pathogenic mechanisms and breeding for disease resistant plant (Steiner et al., 2009; Son et al., 2013).

Because lack of the pathogen-specialized patterns that typically induce gene-for-gene-mediated resistance in the host (van Eeuwijk et al., 1995), the infection and spreading of F. graminearum are easily influenced by the environment. The study of pathogenesis mechanisms could be accelerated by analyzing of the F. graminearum pathogenicity. It is necessary to make a standard and an effective protocol of inoculation which is repeatable and accurate. One of the most important method to prevent FHB is breeding for resistant plants. Numerous studies have shown that inheritance of resistance of wheat to FHB is of a quantitative nature. Therefore, the major task of research FHB resistance is to map the quantitative trait loci (QTLs) region, and a large number of QTLs were described by genetic mapping in diverse wheat germplasm (Buerstmayr et al., 2009; Dhariwal et al., 2018). To verify the functions in QTLs region, an effective inoculation protocol is indispensable. However, the traditional wheat inoculation method for resistance identification is using the conidial suspension to widely sprinkle on the wheat surface instead of inoculation in the specific position of wheat in the field. This inoculation method is constrained by many factors, such as lower accuracy or stability, and sensitivity to environment (Fernando et al., 1997; Francl et al., 1999). The objectives of this protocol are to introduce a method of F. graminearum inoculation, which is standard, effective and repeatable on wheat in a growth chamber. It could help to improve the analysis accuracy and reduce the costs to some extent. In brief, the method can lay a foundation for the research of FHB pathogenesis and resistant breeding.