Response of two sugarcane clones towards Sporisorium scitamineum infection

Abstract Smut disease, caused by the basidiomycete fungus Sporisorium scitamineum , is one of the major diseases in sugarcane worldwide. The response of sugarcane varieties to S. scitamineum infection varies, which depends on their resistance characteristics to the pathogen. The resistance of sugarcane also influences the yield loss caused by the disease. In susceptible varieties, smut disease can cause severe yield losses of up to 70% or more. One of the factors contributing to the resistance of sugarcane varieties to S. scitamineum is their ability to produce chemical metabolites, such as phenolic compounds, which serve as a defense response of sugarcane to smut disease. Our research aimed to unravel the reaction of sugarcane after being infected by S. scitamineum teliospores. Meristematic tissues of two different sugarcane clones, ASA Agribun and J19R17 325/15/3-9 (a putative sugarcane mutant), were inoculated by dipping and injection with S. scitamineum teliospores. The research was arranged in a Completely Randomized Design with four treatments and replicated four times. We observed the distribution of S. scitamineum mycelia within meristematic tissues and phenolic compound content after several time periods of inoculation. Our results revealed that there was no mycelial distribution detected on a putative mutant after seven days of inoculation. On the other hand, the mycelia occupied (19.44%) within a meristematic tissue of ASA Agribun. In addition, a putative mutant produced higher total phenolic compounds (0.225 mg/g) than ASA Agribun (0.06 mg/g). These results indicate that the existence of phenol influenced the resistance of sugarcane to S. scitamineum infection.