| Oriental melon(Cucumis melo var.makuwa Makino)has a high economic value and brings great potential to melon cultivation.But as a respiration type fruit,coupled with its own sweet and juicy characteristics,it is extremely perishable after harvest.Grafting is widely used as a method that can overcome continuous cropping obstacles,enhance plant growth,and improve plant resistance.In production,grafting has the phenomenon of prolonging the fruit maturity period and changing the fruit quality,which also has a certain impact on the fruit quality characteristics during shelf life.In order to study the effect of grafting on the shelf-life characteristics of muskmelon fruit and on the expression of ethylene synthesis-related genes,this experiment used ’Yinquan No.1’ and ’Shengzhen No.1’ as scion and rootstock,and adopted the method of double broken roots.After the commodity is mature,the fruits are stored in a simulated shelf life environment,and samples are taken every two days.First of all,the physiological indexes of fruits during shelf life were measured,and the quality change characteristics of melon fruits during shelf life were determined;Secondly,use gas chromatography,enzyme-linked immunoassay and other methods to determine the ethylene release,respiration rate and ethylene synthesis-related enzyme activities of melon fruits during shelf life,and determine the early,middle and late shelf life according to the ethylene jump;and finally real-time fluorescence quantification(q RT-PCR)Technology to determine the expression of genes related to ethylene biosynthesis and ethylene signal transduction in fruits during shelf life,and to clarify the key steps of grafting affecting ethylene biosynthesis and signal transduction.Exploring the effects of grafting on fruit quality characteristics during shelf life and the changing characteristics of ethylene synthesis provides a theoretical and practical basis for further extending the shelf life of melon fruits.The main findings are as follows:1.There is no significant change in color during shelf life;grafting significantly reduces the hardness of the melon fruit in the late of the shelf life;significantly increases the weight loss rate in the middle and late of the shelf life;significantly increases the SSC content in the midddle of the shelf life.2.Grafting significantly reduced the ethylene release and ACO enzyme activity in the middle of the shelf life,and significantly reduced the respiration rate during the respiratory jump period.The respiratory jump peak was 2 days before the peak of ethylene release.3.From the perspective of ethylene biosynthesis pathway,grafting significantly reduced the gene expression of Cm ACS1、Cm ACS5-1、Cm ACS7、Cm ACS10-1、Cm ACS10-2、Cm ACS11、Cm ACO1、Cm ACO4 and Cm ACO6 in the middle of the shelf life.4.From the perspective of ethylene signal transduction,it was found that grafting significantly reduced the expression of Cm ETR1、Cm ETR3、Cm EIN2-3 and Cm ERF2 genes in the middle of the shelf life,and significantly increased the gene expression of Cm ERF1. |
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