Effects Of 24-Epibrassinolide On The Relationship Between Sugar Metabolism And Cold Resistance Of Apricot Fruit During Storage

Although low-temperature storage can effectively control the rot of apricot fruits,it can easily lead to the occurrence of chilling injury.The change of soluble sugar content can enhance the chilling resistance of plants.In this study,Xinjiang Saimaiti and Diaogan apricot were treated with 0.9 mg/L 24-epibrassinolide,and explored the effects of 24-epibrassinolide on changes of storage quality,sugar content and related metabolic enzyme activities of apricot fruits during storage at 25 °C and 0 °C,this is to provide a theoretical reference for improving the protective mechanism of sugar under low temperature stress and the low temperature adaptive induction of postharvest fruits.(1)The Saimaiti apricot fruit that treated with 0.9 mg/L EBR inhibited the increase of decay rate at 25 °C and the increase of cold injury index,cold injury incidence,malondialdehyde content,and cell membrane permeability at 0 °C,effectively inhibited the cold damage of Saimiti apricot,it also delayed the increase of weight loss rate,and the decrease of hardness,SSC,TA,and Vc content of Saimaiti apricot fruit during the storage.(2)The Saimaiti apricot fruit that treated with 0.9 mg/L EBR delayed the decline of fructose,glucose and early sorbitol content,promoted the accumulation of sucrose at 25 °C.When Saimaiti apricot was stored at 0 °C,the content of fructose and glucose showed a gradual upward trend,EBR increased the content of fructose,glucose and sorbitol by increasing the activity of AI,NI,SSc,SPS,and SDH,but the sucrose content was decreased.EBR enhanced Saimaiti apricot fruit resistance to cold stress by increasing fructose and glucose content.(3)The Diaogan apricot fruit that treated with 0.9 mg/L EBR significantly inhibited the increase of rotting rate at 25 °C and inhibited the occurrence of chilling injury at 0 °C,and it also had a positive effect on the postharvest quality of Diaogan apricot.(4)The Diaogan apricot fruit that treated with 0.9 mg/L EBR significantly increased the apricot fructose,glucose and sucrose content at 25 °C.Compared to storage at 25°C,the contents of apricot fructose and glucose were significantly increased at 0°C.By increasing the activity of AI,NI,SSc,SPS,SDH and SOX,the fructose and glucose content were improved of Diaogan apricot fruit during storage at 0 °C,in order to delay the occurrence of fruit chilling.In summary,apricot fruit with 0.9 mg/L EBR treatment has a positive effect on the storage quality of postharvest apricot fruits at 25 °C and 0 °C.Compared with the changes in sugar content at 25 °C and 0 °C,it is considered that the effective control of chilling injury of apricot fruits by EBR may be closely related to the increase of fructose and glucose content.