The effect of short term temprature stress with H₂O₂ and CaCl₂ on two pepper spicies ( Hot and Bell pepper) in diffrent growth stage

High-temperature effects a change in biochemical, physiological and also molecular change in plants’ metabolism such as chemical analysis of molecules, destruction of nucleic acids, reduction in photosynthesis, increase in respiration and disruption to membrane permeability. These alterations, in consequence, cause damage to plant such as inhibiting its growth and reducing the yield. This study was conducted in green house of Isfahan University of Technology to evaluate the effect of foliar application of H₂O₂ (1 Mm) and CaCl₂ (1 Mm (under high-temperature condition on two spicies of pepper (hot pepper and bell pepper) in a combined analysis as a completely randomizes design with two temperature treatment (25±2Cº and 40±2Cº) in two growth stage ( vegetative and reproductive) and in two time of factor measurement ( after stress and after recovery) with three replication for each treatment. The result of the study indicate that the use of CaCl₂ and H₂O₂ in two spices and both of growth stage and both of time of measurement increases prolin, phenol, antioxidant capacity, calcium, SPAD index, chlorophyll fluorescence and reduce MDA and electrolyte leakage. H₂O₂ reduce level of internal H₂O_2. Bell pepper in both growth stage and both time of measurement indicated more in prolin, phenol, antioxidant capacity, calcium, SPAD index, chlorophyll fluorescence and less in reduce MDA, electrolyte leakage and H₂O₂.Finally it can be concluded that simultaneous application of CaCl₂ and use bell pepper spice whether in optimum condition or stress one, brings a positive effect on physiological characteristics of plants. Therefore, damages cause by high-temperature stress can be reduce by using CaCl₂ and bell pepper, promote plant growth and repair stress damages.