Physiological responses of resistant and susceptible pepper plants to exogenous proline application under Phytophthora capsici stress

Phytophthora capsici Leon. is the main pathogen that limits production of peppers. In this study, effects 1 and 10 mM proline (Pro), prior to exposure resistant (CM-334) susceptible (SD-8) pepper seedlings P. , on some physiological parameters were investigated. A lower Pro concentration (1 mM) was found be more effective than in increasing stress tolerance CM-334 cultivar. Namely, cultivar, highest chlorophyll a b carotenoid, glucose fructose content 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity percentage detected seventh day after application + while lowest malondialdehyde (MDA) amount measured third same treatment. The ferric reducing antioxidant power (FRAP) increase determined application. treatments SD-8 cultivar somewhat differed; amounts anthocyanins, fructose, total protein endogenous application, MDA DPPH % FRAP values with Although differences between cultivars, against general resulted positive effect photosynthetic pigments, soluble carbohydrates capacity pepper. exogenous helped non-resistant overcome stress.