Infl uence of Phytophthora capsici L. inoculation on disease severity, necrosis length, peroxidase and catalase activity, and phenolic content of resistant and susceptible pepper (Capsicum annuum L.) plants

Authors : Esra KOÇ, Ayşen Sülün ÜSTÜN

Pages : 357-371

View : 18 | Download : 5

Publication Date : 2012-12-01

Article Type : Research Paper

Abstract :This study explored the level of infection caused by different inoculum concentrations insert ignore into journalissuearticles values(102, 103, and 104 zoospores mL-1); of Phytophthora capsici in 3 pepper cultivars at days 2, 4, and 6. The effect that the infection induced on the peroxidase insert ignore into journalissuearticles values(POX);, catalase insert ignore into journalissuearticles values(CAT);, and phenolics of resistant and sensitive seedlings, as well as the defense mechanism against the pathogen, were also investigated. The resistance of PM-702 against the isolate used was high, whereas KM-Hot and DEM-8 displayed sensitive reactions. As a result of analyses of the leaves and stems from the 3 pepper cultivars, important changes in biochemical parameters were observed between resistant and sensitive cultivars after inoculation with the root rot pathogen P. capsici. The maximum increase of POX and CAT was observed in the resistant PM-702 cultivar. However, with a high inoculum concentration insert ignore into journalissuearticles values(104 zoospores mL-1);, a loss of CAT activity was determined, especially in susceptible cultivars. The maximum increase in phenolics was detected in leaves of susceptible DEM-8 and stems of PM-702 on day 6 following infection. The results suggest that during Phytophthora root rot development there is a relation between the disease induced by P. capsici and the antioxidant system.
Keywords : Key words Antioxidants, defense responses, plant disease, plant pathogen interaction