Diversity Analysis of Leaf Phenotypic and Fruit Quality Traits Among Six Superior Trees of Nai Plum (Prunus salicina Lindl. var. cordata)

This study analyzed the phenotypic and internal fruit quality diversity of six superior Nai plum trees to provide detailed phenotypic profiles and preliminary relational hypotheses, supporting superior genotype re-selection for breeding. Using leaves and mature fruits, we conducted diversity, correlation, and principal component analysis (PCA) on all quantitative traits. The average Shannon–Wiener index (H′) for qualitative traits was 0.543, and the average coefficient of variation for quantitative traits was 19.98%. Correlation analysis revealed complex trait relationships, including the synchronous variation between the total number of soluble solids (TSS) and reducing sugars (RS) or soluble sugars (SS) and the opposite trends between the TSS and potassium (K), magnesium (Mg), or soluble protein (SP). PCA extracted four principal components (cumulative contribution: 91.074%) from all traits. Based on factor scores, S6 ranked highest, indicating its potential as a comprehensive candidate. The findings offer a theoretical basis for Nai plum cultivation and breeding.