Sclerotinia stem rot (SSR), caused by the necrotrophic fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, poses a significant threat to yield and seed quality worldwide. Applying excessive fungicides to control S. sclerotiorum causes a lot of potential environmental problems. Thus, eco-friendly control methods are necessary to be developed. Selenium (Se) can sometimes serve as a beneficial element for plant growth and development. Selenium, as well as dissolved organic matter derived from rape straw pretreated with Se in soil, can inhibit mycelial growth of S. sclerotiorum by damaging the membrane system and interfering with its metabolism (Jia et al. 2018, 2019).