Abstract: Forty-four apple varieties were evaluated for differences in fruit quality indicators including individual fruit weight, flesh weight, edible rate, volume, density, longitudinal diameter, transverse diameter, shape index, core size, L*, a* and b*. Meanwhile, these quality indicators were analyzed by correlation analysis and principal component analysis (PCA). The results showed that the 12 quality indicators revealed a significant difference among 44 different apple varieties. A significantly positive or negative correlation was observed among some of the quality indicators. Three major components with a characteristic value larger than 1 during PCA were extracted and the cumulative variance contribution rate was 82.618%. The first principal component represented fruit size; the second principal component represented skin color and the third principal component represented fruit density, shape index and core size.

Key words: apple, quality trait, principal component analysis