A simple in vitro approach for assessing resistance and pathogenicity in the Fusarium head blight-Triticum spp. pathosystem

An effective in vitro approach to predict host resistance and pathogenicity of Fusarium species causing head blight (FHB) may improve resistance evaluation in wheat. The in vitro capacity of four Fusarium species to cause disease on young plant parts of six bread and durum wheat cultivars with known quantitative resistance was assessed using a coleoptile infection assay. Significant differences were detected in pathogenicity among Fusarium species and susceptibility/resistance levels among wheat cultivars. Only the resistance measured by coleoptile length (CL) was correlated with resistance criteria generated under in vitro (area under disease progress curve, r = -0.951), controlled (Type I and Type II, r = -0.813 and r = -0.907, respectively) and field (Type I during 2018/19 and 2019/20, r = -0.857 and r = -0.866, respectively) conditions. Moreover, the values of seed germination and CL components were significantly correlated with pathogenic indices obtained under several experimental conditions. CL predicts quantitative traits at the earliest and latest wheat development phases during disease invasion. Thus, CL may suggest a veritable potential of simple, quick, and trustworthy early screening of FHB resistance in wheat cultivars and the pathogenicity of Fusarium species.