基于主成分和灰色关联度分析的鲜食枣果实品质评价

Evaluation of fruit quality of fresh-eating jujube based on principal component and gray correlation analysis

【目的】完善果实品质评价标准,筛选高品质的鲜食枣品种,为枣树栽培和品种选育提供参考依据。【方法】以25个优选的鲜食枣实生株系的果实为研究对象,测定果实品质相关指标:纵径、横径、果形指数、单果质量、维生素C含量、可滴定酸含量、可溶性固形物含量、可溶性糖含量、固酸比、糖酸比,分别采用主成分分析法和灰色关联度分析法进行果实品质的综合评价。【结果】优选株系果实品质指标的变异系数为7.92%~37.92%,单果质量、维生素C含量、可滴定酸含量、固酸比、糖酸比的变异系数较大,变异系数大于20%,纵径、横径、果形指数的变异系数较小,变异系数小于10%。通过主成分分析,从10项果实品质指标中提取出4个主成分,其累积方差贡献率达90.90%,可代表鲜食枣果实品质90.90%的信息量。第1主成分反映的指标为可滴定酸含量、固酸比、糖酸比,第2主成分反映的指标为横径、单果质量,第3主成分反映的指标为可溶性固形物含量、可溶性糖含量,第4主成分反映的指标为维生素C含量。根据所建立的鲜食枣果实品质综合评价模型,综合品质排序前5位的株系分别为Z-4、2-2、Z-3、F-4、Z-1。采用因子分析法确定各品质指标的权重,纵径、可滴定酸含量的权重最大,均为0.114,结合灰色关联度分析法,构建了灰色关联度综合评价模型,采用该模型得出的综合品质排序前5位的株系分别为Z-4、2-3、2-2、F-4、Z-3。采用2种方法得出的各株系排序的秩相关系数为0.895。【结论】Z-4、2-2、Z-3、F-4株系的枣果实综合品质较优。根据采用主成分分析法和灰色关联度分析法建立的综合评价模型,对鲜食枣果实品质进行评价,结果全面可靠。

【Objective】To improve the evaluation standard of fruit quality and screen high-quality fresh-eating jujube varieties,which provides a reference for the cultivation and variety selection of jujube.【Method】The fruits of 25 fresh-eating jujube strains were used as research materials.The related indexes of the fruit quality including longitudinal diameter,transverse diameter,fruit type index,single fruit mass,vitamin C content,titratable acid content,soluble solid content,soluble sugar content,solid acid ratio and sugar-acid ratio were measured.And the principal component analysis and gray correlation analysis were used comprehensively to evaluate the fruit quality.【Result】The variation coefficient of fruit quality index of the selected strains was 7.92%-37.92%.The single fruit mass,vitamin C,titratable acid,sugaracid ratio and solid acid ratio showed greater coefficient of variation,which were more than 20%.The longitudinal diameter,transverse diameter and fruit type index showed relatively lower coefficient of variation,which were less than 10%.The four principal components were extracted from 10 fruit quality indexes by principal component analysis,and the cumulative contribution rate was 90.90%,which represented 90.90%information of fruit quality.The first principal component reflected index of titratable acid,solid acid ratio and sugar-acid ratio.The second principal component reflected index of horizontal diameter and single fruit mass.The third principal component reflected index of soluble solid content and soluble sugar content.The fourth principal component reflects index of vitamin C content.On the basis of the comprehensive evaluation model of fresh-eating jujube fruit quality,the top five strains were Z-4,2-2,Z-3,F-4 and Z-1.The weight of each quality index was determined by factor analysis method,and the weight of longitudinal diameter and titratable acid were the largest,which was both 0.114.Combined with gray correlation analysis,the comprehensive evaluation model of weighted correlation degree was established.The top five strains by the model were Z-4,2-3,2-2,F-4,Z-3.The rank correlation coefficient of two methods was 0.895.【Conclusion】The comprehensive quality of jujube fruit of Z-4,2-2,Z-3 and F-4 are better.The comprehensive evaluation model established by principal component analysis and gray correlation analysis is comprehensive and reliable.