Effect Of AVG And 1-MCP On Fruit Physiological Properties And Ethylene Production During Ripening In Melon

Melon is an important horticultural crop.Oriental sweet melons' stage of growth and development is short,the peel is thin,and most of cultivars were harvested in the summer.At room temperature,the quality of post-harvest fruit extremely reduced,and marketable life were short.'Cuili' melon was taken as experiment material.Melon fruit were harvested on 40 days after pollination,and treated by following treatments:1.fruit were sprayed with AVG(an inhibitor of ethylene synthesis)at 130?L/L on 20 days before harvest;2.fruit were exposed to 1-MCP(an inhibitor of ethylene action)at 1?L/L for 24 h;3.fruit were exposed to ethylene at 10?L/L for 24 h;4.Untreated melons as the control.Post-treated fruit were stored at room temperature(24??29?)and 5±2?,respectively.The changes of flesh firmness,total soluble solids,organic acid,soluble sugar,TSS/TA,juice PH,rind color,electrical conductivity and ethylene production of fruit in melons were investigated.Those provide theory basis of formulating for melon fresh-keeping.The main results were as follows:1.During ripening,the declining of flesh firmness and increase of electrical conductivity were delayed significantly by AVG and 1-MCP treatments,whereas were enhanced by ethylene treatment.Compared with room temperature,low temperature storage can slow down the decrease of flesh firmness and increase of electrical conductivity.The effect of four treatments is:AVG>1-MCP>control>ethylene.2.As the melon ripened,total soluble solid(TSS)content of fruit gradually reduced,and the decrease was inhibited by low temperature.Total soluble sugar content was not significantly changed by different treatments or low temperature.With the time of storage extended,vitamin C content and ripening index(TSS/TA)of fruit gradually reduced,and oxidative decomposition of vitamin C content was delayed by low temperature.3.Titratable acidity content and PH of juice in fruit were not significantly different between room temperature and 5?,and their changes were not affected by different treatments.4.During storage,the rind lightness and H°(hue angle)value of melons did not significantly changed,and is not affected by low temperature.C*(chroma)value gradually reduced.Compared with other three treatments,the rind color of fruit treated with AVG were more intense(higher C*value)(p<0.05)because of the green spot.5.At room temperature,ethylene production of melon fruit treated with AVG and 1-MCP were significantly inhibited within 14 days of storage,while no significant difference in the late storage.The coming of ethylene peak can be delayed by low temperature.The ethylene production was similar between low temperature and room temperature.6.At room temperature,there was no significant different in ACC oxidase activity between ethylene treated fruit and control.ACO and ACS enzyme activity in melons were inhibited by AVG treatment.1-MCP treatment can significantly inhibited ACO enzyme activity within 8 days of storage,but stimulated ACS enzyme activity.AVG was the most effective inhibitor of ethylene production in this trail.7.The experiment results indicated that flesh firmness,electrical conductivity,ethylene production,ACO and ACS enzyme activity in ripening melon fruit were regulated by ethylene.While total soluble solid,soluble sugar,vitamin C,titratable acidity content,ripening index(TSS/TA),PH of juice,rind lightness,C*(chroma)and H°(hue angle)value were not regulated by ethylene.