Effect Of 24-Epibrassinolide On The Disease Resistance Of The Postharvest Apricot Fruits

Reactive oxygen metabolism and phenylpropane metabolism play an important role in improving fruit disease resistance.The effects on disease resistance of postharvest apricot fruits by 24-Epibrassinolide?EBR?treatment were investigated.“saimaiti”apricot fruits as the experimental material,the reactive oxygen metabolism,phenylpropane metabolism and storage quality were determined.The theoretical reference was provided for the application of EBR in the preservation of apricot fruit.The main results are as follows:?1?The apricot fruit was treated with EBR at different concentrations?0 mg/L,0.5 mg/L,0.7 mg/L,0.9 mg/L,1.2 mg/L,1.5 mg/L?and stored at 4?,90%-95%RH.The natural incidence,inoculation injury incidence and lesion diameter of apricot fruit were determined regularly.The results showed that the natural morbidity,the incidence of injury and the diameter of the apricot were inhibited with the EBR treatment at the concentration of 0.9 mg/L is best..the response surface method was used to obtaining the optimal conditions of EBR for the decompression osmosis of apricot fruit were 0.9 mg/L,0.05 MPA and 2min.?2?The hydrogen peroxide?H₂O₂?content of apricot fruit in the early storage time was raised by EBR treatment to initiate a series of defensive responses.The results showed that the content of H₂O₂ was increased by 0.9 mg/L EBR treatment in the early storage period,the activity of superoxide dismutase?SOD?,peroxidase?POD?,polyphenol oxidase?PPO?were enhanced,and the activity of catalase?CAT?was maintained,while the concentration of O₂^-·was reduced.It is indicated that the ripening and senescence are delayed,and the disease resistance is enhanced by regulating the antioxidant defense system enzyme activity in fruit with EBR treatment.?3?The phenylpropane metabolic pathway was activated by 0.9 mg/L EBR treatment.The activity of PAL,C4H,4CL,CHT and GLU were increased.Lignin and total phenol contents were promoted,and the content of flavonoids was increased significantly in the later storage time.It is indicated that the resistance of the fruit can be enhanced by regulating the phenylpropane metabolic pathway with 0.9 mg/L EBR treatment.?4?The relevant indicators of the quality of apricot fruits were determined.The results showed that the natural incidence of apricot fruit rate,incidence and lesion diameter were inhibited obviously,the SSC,TA,Vc content were delayed.The respiration and MDA were decreased;Thereby the quality of fruit was improved during the storage.It is indicated that the resistance of the fruit can be enhanced by regulating the antioxidant defense system enzyme activity and phenylpropane metabolic pathway the quality of fruit was improved during the storage and thus enhancing the disease resistance of apricot fruit,with 0.9 mg/L EBR treatment.