Effect of Trichoderma harzianum against Fusarium oxysporum in resistant and susceptible tomato cultivars

Abstract

Fusarium wilt disease presents a substantial challenge to tomato production, especially in an open field environment. The peroxidase (POD) activity and total phenolic compounds (TPCs) play a crucial role in measuring the antioxidant capacity of plants. Understanding the variations in the POD and TPC levels during disease-induced stress becomes important for effectively managing Fusarium wilt and enhancing tomato production. This study investigates the impacts of Trichoderma harzianum inoculation through the root drip method on five tomato cultivars. It compares these cultivars to their non-treated counterparts when they are subjected to infection by Fusarium oxysporum f. sp. lycopersici (Fol). The results showed that the level of resistance to Fol is based on the specific tomato cultivar. Notably, 'MT26' exhibited the lowest disease severity index (DSI), indicating a strong response, whereas 'CLN3682F' showed notable susceptibility. Regarding the POD and TPC activity, its exhibition differed in compatibility with the response of each tomato cultivar to Fusarium wilt disease. The resistant cultivars increased the POD activity after the Trichoderma induction before the Fol inoculation, and this activity was further boosted when exposed to disease conditions. Consequently, enhancing the POD and TPC levels during the initial stages could potentially serve as a systemic defence mechanism of tomatoes against the Fusarium wilt disease.