Morphological, pathological and molecular characterisation of rice sheath blight disease causal organismRhizoctonia solaniAG-1 IA in Egypt

Rice sheath blight disease caused by Rhizoctonia solani is considered a distractive soil-borne disease of rice production worldwide. The study aimed to determine the causal organism of sheath blight symptoms in Egyptian rice fields. Sheath blight symptoms were first observed in a small area during 2013, 2014 and 2016 seasons, later in a wide area of rice fields in 2016 to 2018 seasons. Pathogen identification was carried out based on morphological traits and internal transcribed spacer sequencing. Thirty-six isolates were identified as R. solani fungus. The isolates exhibited a wide range of variability in their morphological traits and virulence patterns. Five isolates were sequenced and aligned with Chinese isolates with 75–100% identity. This is the first report of R. solani AG-1 IA that associated with rice sheath blight in Egypt. Initiate a breeding program for disease resistance and integrated disease management procedures are important to keep the disease under control.