Study On Harvest And Storage Quality And Induced Disease Resistance Of Apricot Fruit By Oligochitosan Pre-treatment

Saimaiti apricots of XinJiang are taken as the experimental material of this paper, whosepurpose is to study how the harvest and storage quality, reactive oxygen metabolism, diseaseresistance related enzyme activity and defense substances are effected by pre-harvestoligochitosan treatment. The influence of pre-harvest oligochitosan treatment on the harvest,storage quality and disease resistance is also analyzed here. The findings provide theoretical basesfor the study of how oligochitosan affect the disease resistance of harvest fruits on the one hand,and has realized the purpose of reducing the use of chemical bacterian-cide and improving safetyof fruits storage on the other hand.（1）Different oligosaccharide solutions,3000u and5000u molecular weight and density of0.01%、0.05%、0.25%, were applied to the apricots in different periods, namely the young fruitperiod, the stigmas period, the veraison period, and right harvest. Storage was done in coldwarehouses at4°C and90%-95%RH. The result shows the solution with a molecular weight of5000was the best option. Further analysis of natural and injury incidences indicate that thesolution with5000molecular weight and0.05%density provide the maximum inhibition to suchincidences.（2）Pre-harvest oligosaccharide treatment may remarkably increase reactive oxygen andresistance related enzyme activities in the fruit. The solution of5000molecular weight and0.05%density may strongly induce early and quick accumulation of signal molecules of H2O2, NO andethylene, which suppressed the rises of H2O2and ethylene and the falling of nitric oxide at laterstages. The activities of such enzyme are increased as CAT, GR, POD,APX,SOD, POD. Andenhanced are the contents of HRGP, lignose, MAPK and total phenols. Activities of CHT, GUNand PAL are also multiplied.（3） The treatment of this solution of5000molecular weight and0.05%density effectivelyreduces the hardness of the fruit and the chlorophyll content; prolongs the accumulation of titrable acid, ascorbic acid and soluble solid; and contains the loss of weight and disease index. It provesto be a valuable treatment for better storage of fruit after harvest.