Abstract:In this study，a trehalose-based composite preservation liquid containing 108 CFU/mL of Pichia membranifaciens KD-316-3 was prepared.In order to explore the antifungal mechanism and application effect of this composite preservation liquid，the Alternaria species-induced black spot in fruits was studied in vitro，and the composite preservation liquid was applied to winter jujube in a preservation experiment.The experiment results showed that the composite preservation liquid inhibited the growth of Alternaria species in vitro with an antagonistic efficiency of 26.48%.It deformed the morphology of mycelium，causing extravasated electrolytes，leaked nucleic acid in mycelium，and decreased intracellular soluble protein content.During the storage of winter jujube，the composite preservation liquid inhibited the rates of weight loss of winter jujubes，effectively slowed down the spot and rot of winter jujubes，affected the content of malondialdehyde and the activity of polyphenol oxidase in the fruits，and improved the activity of peroxidase.Comprehensive analysis showed that composite preservation liquid containing Pichia membranaefaciens KD-316-3 could be used for the preservation of winter jujube.It could inhibit the rot caused by pathogenic fungi and maintain good fruit quality.