Regulation Of Chilling Injury In 'xuxiang' Kiwifruit By Ethylene Treatment During Cold Storage

Kiwifruit is rich in nutrients,unique in taste and rich in vitamin C,so it is very popular among consumers.Kiwifruit is very easy to turn soft and decay at room temperature after harvest.The low temperature storage can effectively prolong its storage period.However,kiwifruit is a cold-sensitive fruit,and ordinary cold storage is easy to induce chilling injury,resulting in serious fruit loss during shelf life.As a natural plant hormone,ethylene can induce and promote the ripening of fruits and vegetables,increase the aroma,taste and color of fruits and vegetables.In addition,ethylene also plays an important role in tolerance and resistance to biotic and abiotic stresses.Exogenous ethylene treatment had achieved remarkable results in the research of chilling control of various fruits and vegetables,because of its non-toxic,non-polluting and simple operation.In order to clear the effect of ethylene on chilling injury of‘Xuxiang'kiwifruit,different concentrations of ethylene treatment,and ethylene with 1-MCP were experimented.After all treatments,0±0.5°C?RH95%?was stored for 100 d to study the effect of ethylene on chilling injury of kiwifruit at0°C.The research results were as follows:1.Three concentrations of ethylene treatment increased the chilling injury of kiwifruit to varying degrees,but there were differences among treatments:the treatments with 5?L·L^-1 and 10?L·L^-11 ethylene showed chilling symptoms of waterlogging on 40 d,and the chilling injury index,chilling injury rate and rot rate were higher,while treatment with 1?L·L^-1 ethylene and control showed chilling symptoms at 50 d.2.During the period of storage,different concentrations of ethylene treatment maintained the higher soluble solids content of kiwifruit,but increased the respiration rate and ethylene release of the fruit,promoted the respiratory and ethylene peaks,and increased the relative cell membrane permeability and accumulation of MDA,and the higher the concentration,the stronger the effect.3.The treatment with 0.25?L·L^-1 1-MCP and combination of 0.25?L·L^-1 1-MCP+1?L·L^-1 ethylene treatment both effectively alleviated the chilling symptoms such as water staining and lignification of‘Xuxiang'kiwifruit,reduced the chilling injury rate,chilling injury index,the respiratory intensity and ethylene release,inhibited cell membrane permeability and MDA content,maintained cell membrane structural integrity,increased the activities of superoxide dismutase,catalase and ascorbate peroxidase and inhibited the peroxidation of membrane lipids,thereby reducing the occurrence of chilling injury in kiwifruit.4.Ethylene treatment promoted the accumulation of lignin and the formation of lignified tissue during cold storage,promoted the deformation and disintegration of pulp cells,and promoted the softening of pulp;while the treatment of 1-MCP and 1-MCP+ethylene treatment had the effect of delaying these effects and significantly reduced the fruit rot rate during cold storage.The effect of 1-MCP alone treatment was more obvious.In summary,the post-harvest treatment of ethylene on‘Xuxiang'kiwifruit aggravated chilling injury,and higher concentration would accelerate the occurrence of cold damage and promote fruit softening and decay;suitable concentration of 1-MCP treatment after harvest had the effect of reversing the above adverse effects of ethylene.