不同发育阶段苦瓜皂苷变化特征及相关性分析OA北大核心

[Objectives]The paper aimed to study the variation characteristics,differences and correlation of saponins in different development stages during fruit setting,in order to provide a scientific basis for functional breeding,optimal harvesting period determination and quality control of bitter gourd(Momordica charantia L.).[Methods]The independently selected bitter gourd'Minglü 5'was selected as experiment object.The composition,content and physicochemical factors of bitter gourd saponins were detected by vanillin method,high performance liquid chromatography-mass spectrometry,ion emission spectrometer,and other methods,and the results were analyzed by chemometrics.[Results]The total saponin contents of bitter gourd varied significantly at different developmental stages(P＜0.01),showed an overall downward trend with a range of 3.14-10.64 mg·g-1,while the total saponin contents of single fruit showed an upward trend with a range of 9.03-77.14 mg.A total of 55 common peaks were calibrated in the characteristic chromatogram,which contained most of the information about bitter gourd saponins.The relative standard deviation(RSD)range of the common peak area at different developmental stages was 14.68％-193.01％,with a range of over 50％of the common peaks accounting for 85.45％.The result of cluster analysis showed 5 distinct groups which were consistent with principal component analysis.The three batches of young fruit stage were clustered into one group alone,the expansion stage was clustered into one group,and the three maturity stages were clustered into one group.Partial least squares discriminant analysis(PLS-DA)showed little diversity in green maturity stage to full maturity stage,but it was a significant difference compared to the young fruit stage and the swelling stage.And 10 characteristic differential metabolites were identified by mass spectrometry.Correlation analysis showed that the differential metabolites should highly significant positive correlation with total saponins,fruit shape index,nitrogen,phosphorus and copper during fruit setting(P＜0.01),and highly significant negative correlation with fruit length,fruit horizontal diameter,single fruit weight,flesh thickness and moisture content(P＜0.01).[Conclusions]The saponin composition of bitter gourd was relatively stable at different developmental stages,and there were significant differences in the total saponins and their compositions.The color-changing period could be used as the optimal harvesting period for the saponins.The 10 monomer saponin components such as momordicoside L and momordicoside K were the main active monomers at different developmental stages,whose changes were closely related to the total saponins,fruit shape index,nitrogen,phosphorus,and copper elements.