Study On The Mechanism Of Alleviating Chilling Injury Of Green Pepper By Exogenous Factor Treatments

Green peppers are cold-sensitive plants, they are susceptible to chilling injurywhen stored at low temperature, which is easy to cause postharvest fruit qualitydecline and even spoiled.In order to study the effects of exogenous substance on chilling-resistance ofgreen pepper, to research its physiological mechanism and variation rule of fruitquality, membrane damage and protection enzymes activity, pepper as basic testingmaterial were treated by SA (salicylic acid), BR (Brassinolide) GB (Glycine betaine).Methods of the Real-time Fluorescent Quantitative PCR (Real-time Q-PCR) wasemployed to analysis the changes of genes expression levers during the chilling stressprocess of green pepper. The main results showed as follows:The impact of different concentrations（0.5mmol/L，1mmol/L，2mmol/L）of SAsolutions on chilling injury development of green pepper fruit during cold storagewere studied. The results showed that green pepper with SA treatment could preventthe occurrence of chilling injury, improve the quality of pepper with cold-stored,delay the degradation of chlorophyll and the decline of Vc content. In addition, theraise of cell membrane permeability and the accumulation of MDA content as well asthe LOX activity were inhabited, antioxidant enzymes (POD, CAT, GR and APX）activities were also maintained at a high level when stored at3℃. The bestconcentration was2mmol/L.The impact of different concentrations（5μmol/L，10μmol/L，15μmol/L）of BRsolutions on chilling injury development, storage quality and Physiological andbiochemical indexes of green pepper fruit during cold storage were studied. Theresults showed that green pepper with BR treatment could prevent the occurrence ofchilling injury, improve the quality of pepper with cold-stored, delay the degradationof chlorophyll and the decline of Vc content. In addition, the raise of cell membranepermeability and the accumulation of MDA content as well as the LOX activity wereinhabited, the membrane lipid protect enzymes (POD, CAT, GR and APX）activitieswere also maintained at a high level when stored at3℃. Green pepper were storedbest in the concentration of15μmol/L. The impact of GB solutions on chilling injury development of pepper fruit duringcold storage were studied. The results showed that GB treatment could prevent theoccurrence of chilling injury, improve the quality of pepper with cold-stored, delaythe degradation of chlorophyll and the decline of Vc content. In addition, the raise ofcell membrane permeability and the accumulation of MDA content as well as theLOX activity were inhabited, antioxidant enzymes (POD, CAT, GR and APX)activities and genes expression levers were also maintained at a high level whenstored at3℃.