Objective To excavate high-quality germplasm resources and provide solid foundation for the selection and breeding of superior and new varieties in the future, it is necessary to analyze the phenotypic traits variation pattern of E. mollis.

Method 100 10-year-old seedlings were selected from the provincial nature reserve of E. mollis located in Yicheng, Shanxi Province. A trait list of E. mollis was compiled according to the quantitative classification method. Various methods were used to reveal the variation pattern of E. mollis germplasm resources.

ResultsThe phenotypic variation of E. mollis ranged from 9.72% to 37.66%, with an average coefficient variation value of 22.26%. H’ of the phenotypic traits varied between 1.056 and 2.213. Correlation analysis showed that phenotypic traits of a single organ correlated significantly with each other, phenotypic traits from different organs showed no correlation. However, the leaf length showed significant correlation with fruit traits. PCA result showed that the first 7 principal components contributed 79.053% to the total variation, and the contribution rate of each trait was scattered. Cluster analysis based on phenotypic traits of fruit showed that all the individuals can be divided into 3 groups at the coefficient distance of 10 and differences among these 3 groups were significant. PCA analysis of phenotypic traits of fruit indicated that yield and kernel related traits can be chosen as the primary target in future E. mollis breeding. Therefore, individual 10, 17, 33, 37, 56 and 74 were chosen as the primary material for future breeding of superior and new varieties of E. mollis.

Conclusion The phenotypic traits variation pattern of E. mollis plantation in Shanxi Province was high, different materials can be chosen based on various breeding targets.