Studies On The Ripening Of Pyrus Communis L. And Mechanism Of 1-Methylcyclopropene Delay Ripening Senescence

The " Cascade " of the late ripening variety in pears is the test material in this article, By studying the different harvest after harvest of fruit in storage conditions at 20℃and 0℃when the fruit store at 20℃after 60d storage conditions, the situation the fruits in Physiological changes, to determine the different harvest time on fruit ripening. The results showed that: 5 September harvest (T1), 15 September harvest (T2), 25 September harvest (T3) post-harvest storage at 20℃, respectively, 12d, 10d, 8d or so after the completion of ripening; T1 fruits that stored at 0℃after 60d and transformed into 20℃storage were less capable of ripening fruit T2, T3, respectively, 8d, 4d or so after the completion of ripening.T2 fruits were treated respectively 0.25μl . L^-1, 0.5μl . L^-1, 1μl . L^-1, 2μl . L^-1 at 20℃, by researching on different concentrations of respiration rate, ethylene, relative conductivity and MDA, hardness, VC, soluble solids, titratable acid, core browning rate of change of core browning after the fruits were treated by 1-MCP, To determine the 1-MCP effects on fruit ripening, and quality. The results showed that: the fruits treated by 0.25μl . L^-1 1-MCP is not obvious on fruit ripening; the ripening time of the fruits treated by 0.5,1μl . L^-1 1-MCP were delayed by 2-4d and 4-6d, and have better quality on fruit ripening; 2μl . L^-1 1-MCP treatment was prevent from the release of ethylene excessively, and promoted the core browning, affected the normal fruit ripening and eating quality.Researching on the delayed fruits of postharvest senescence ripening mechanism at 20℃, with 1μl . L^-1 1-MCP Treatment T2 fruit of the delayed senescence of postharvest ripening mechanism. The results show that the :1-MCP inhibited the pears fruit PG, PME,β-Gal andα-L-Af and other cell wall degrading enzyme activity, slow down pectin, hemicellulose and cellulose degradation, maintain the integrity of the cell wall structure to control fruit ripening and softening, ripening and senescence of extension. 1-MCP treated fruits POD,CAT activity changes slowly, while maintaining SOD activity, inhibition of O2.- production, reduce lipid peroxidation product malondialdehyde production, protection of the integrity of membrane system, slow down ripening aging, thus affecting the shelf life of fruit storage and quality.