关键词: 苹果, 品种, 矿质元素, 因子分析, 聚类分析

Abstract: 【Objective】 Studies on mineral elements characteristics in different apple varieties were conducted to provide a scientific basis for apple nutrition evaluation, apple consumption and parent selection. 【Method】 Seven indexes including K, P, Mg, Ca, Zn, Cu and Mn in 125 apple cultivars were determined and the contents were analyzed by factor analysis and cluster analysis.【Result】 The average contents of 7 mineral elements were followed by the order of K (1112.72 mg·kg^-1)＞P (119.59 mg·kg^-1)＞Mg (65.69 mg·kg^-1)＞Ca (56.96 mg·kg^-1)＞Zn (0.69 mg·kg^-1)＞Cu (0.66 mg·kg^-1)＞Mn (0.63 mg·kg^-1). The coefficient of variation was varied from 19.4% (Mg) to 43.9% (Cu). There were significant differences among K, P, Mg and Ca (P＜0.05), and no significant differences among Zn, Cu and Mn. All of the 7 mineral element contents obeyed the normal distribution by K-S test. The result of factor analysis showed that Cu, K, Mg, P and Mn were the characteristic elements of apples and the cumulative variance contribution rate of the first four components was 86.30%. The F1 (factor 1) represented Cu, K, Mg, P and the top three apple cultivars for F1 score were ‘Qiujin’, ‘May’ and ‘Guoqing’. The F2 represented Mn and the top three apple cultivars for F2 score were ‘Stark Spur Delicious’, ‘Chunxiang’ and ‘Yellow Transparent’. The F3 represented Zn and the top three apple cultivars for F3 score were ‘Yan shan hong’, ‘Szampion’ and ‘4-23’. The F4 represented Ca and the top three apple cultivars for F4 score were ‘Black Ben Davis’, ‘Fujin’ and ‘Pacific Rose’. The top five apple cultivars for synthesis scores were followed by the order of ‘Qiujin’, ‘May’, ‘New Ralls’, ‘Beidou’ and ‘Changhong’. The 125 apple samples were divided into 5 groups by cluster analysis. The first group included 9 samples in which the Ca content was very high, the second group included 28 samples in which the Cu content was very high, the third group included 23 samples in which the Zn content was very high, the fourth group included 44 samples in which the contents of Ca, Cu, K, Mg, P, Zn were relatively low and the fifth group included 21 samples in which the contents of K, Mg, Mn and P were high and the Zn content was low. 【Conclusion】 There were very significant positive correlations among K, Mg, Cu and P, and all the correlation coefficients were greater than 0.5. Cu, K, Mg, P and Mn were the characteristic elements of apples. The compositions of 7 mineral elements were different among different varieties. The 125 apple samples were divided into 5 types including high Ca variety, high Cu variety, high Zn variety, the variety with high Cu, K, Mg, P and Mn contents and the variety with low mineral element contents.

Key words: apple, variety, mineral element, factor analysis, cluster analysis