In this study, 87 walnut resources introduced in Fenyang Walnut Seed Breeding Experimental Garden of the National Forestry Seed Base were used as research objects. The quality and quantitative traits of nut phenotypes were determined, and diversity analysis, principal component analysis, correlation analysis, cluster analysis, and comprehensive evaluation were performed on 6 quality traits and 14 quantitative traits. The results showed that the diversity index of 6 quality traits of 87 walnut nuts introduced in Shanxi ranged from 0.494 to 2.019, among them, nut shape and nucleolar skin color were the phenotypic markers with the most abundant genetic diverse and could be used as a core index for germplasm identification. The coefficient of variation of 14 quantitative traits ranged from 8.88% to 29.33%, among them, the high coefficient of variation in green fruit unit weight, nut wet weight, and walnut kernel rate provided a direct selection basis for the breeding for high-yield and high value-added varieties. Four principal components were extracted by principal component analysis, and the cumulative contribution rate reached 86.934%, which could better reflect the variation information of the main traits, and among them, nut size(PC1) and fruit shape index(PC2) were the dominant factors in phenotypic differentiation. Correlation analysis showed that 14 quantitative traits were associated to varying degrees, the negative correlation between shell thickness and walnut kernel rate provided a theoretical support for the breeding strategy of thin shell high kernel. Cluster analysis divided 87 walnut variety resources into four major groups when the Euclidean distance was 1.2. The result of the comprehensive evaluation indicated that the germplasm with excellent comprehensive performance such as Jufeng and Jinlong 1 could be directly applied to variety improvement, and the special materials such as Ziren required exploration of the unique metabolic pathways by functional genomics to expand the multiutilization scenarios of walnuts.
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