Histopathological studies of sesame (Sesamum indicum) seedlings infected with Fusarium oxysporum

摘要

Sesame (Sesamum indicum L.) is one of the most important and oldest oil seed crops, and vascular wilt caused by the soil-borne fungus Fusarium oxysporum is the most destructive disease of sesame worldwide. Histopathological studies were conducted on sesame plants after artificial inoculation with F. oxysporum. Characteristic disease symptoms such as chlorotic and wilted leaves appeared 15–20 days after inoculation. Light microscopic studies revealed the presence of pathogen in xylem vessels during initial stages. The pathogen then moved to adjacent cortical and epidermal cells intercellularly causing disintegration of the cells. Formation of cavities and plugging of xylem vessels with gum was observed, which retards water and nutrient supply to plants, thus resulting in wilting and ultimately leading to death of plant.