Abstract:This study prepared oligogalacturonides（OGs）by enzymatic hydrolysis of pectin from different sources using perishable and hard-to-store berries as the test object.High performance liquid chromatography（HPLC）and RNA quantitative reverse transcription-polymerase chain reaction（qRT-PCR）were used to study the association mechanism between OGs and fruit softening，and application tests were carried out.Results indicated that OGs prepared by enzymatic hydrolysis of pectin from citrus peels and apple pomace had better effects in alleviating fruit softening，and the firmness of fruit in the treatment group was 1.68 times and 1.40 times that in the control group，respectively.At the same time，different esterification degrees of pectin had varying effects in slowing down fruit softening.By combining HPLC and postharvest physiological analysis，it was found that OGs with a retention time of less than 14 min exhibited excellent regulation of fruit softening.It was found that OGs induced obviously downregulated the genes SlPG2，SlPL3 and SlPL5 related to cell wall degradation by qRTPCR.The application of OGs in berries such as grapes，blueberries，and strawberries also obviously slowed down fruit softening，with fruit hardness in the treatment group being 38.22%，37.48%，and 69.87% higher than that in the control group，respectively.OGs were found to be effective in reducing the loss rate of the aforementioned fruit during storage，which proved that OGs could effectively inhibit the postharvest quality deterioration of berries such as softening and decay.