Objective To clarify the variation patterns of fruit traits in hybrid offspring of Castanea henryi, and to conduct comprehensive evaluation and selection of excellent individual plants.

Method The genetic diversity and variation of 7 shape feature traits and 12 quantitative traits of the fruit phenotype of 143 individual plants of F₁ generation of Castanea henryi were analyzed, and all individual plants were comprehensively evaluated by principal component analysis and grey correlation analysis.

Result The results showed that the diversity index of 6 shape feature traits such as nut shape in F₁ hybrid generation was greater than 0.8, which showed high genetic diversity. Among the 12 quantitative characters, fruit bract mass, total nut weight and single nut weight had a large variation range, and the smallest variation range was the percentage of kernels. The differences of fruit phenotypic characters among single plants were very significant (P < 0.01), which had great selection potential. There were 42 groups of extremely significant correlation ( P < 0.01) and 6 groups of significant correlation ( P < 0.05) among the 12 fruit quantitative traits, and joint selection could be carried out. The highest comprehensive score of single plant was G-98 through principal component analysis and grey correlation analysis, and 10 excellent single plants including G-98 were selected by these two methods.

Conclusion There are rich variations and correlations among various phenotypic traits in the F₁ hybrid of Castanea henryi, and the overlap of comprehensive selection results is high. The results lay a foundation for the creation of new germplasm and the breeding of fine new varieties of Castanea henryi.