Objective  To study the variation of phenotypic traits and the relationship with ecological factors in natural population of Hippophae rhamnoides L. subsp. sinensis Rousi in Shanxi Province, so as to provide technical support for germplasm resource collection, preservation and breeding of H. rhamnoides.

Method  10 phenotypic traits were investigated for 110 superior individuals in 11 natural populations of H. rhamnoides subsp. sinensis from Shanxi, China. The phenotypic variation among populations was studied using analysis of variance, coefficient of variation. The principal component analysis and cluster analysis were used to classify the population.

Result  The correlation analysis revealed the correlation between ecological factors and phenotypic traits. The results showed that 10 phenotypic traits of H. rhamnoides subsp. sinensis were significant (p < 0.05) or extremely significant (p < 0.01) among elite trees of different populations. The average variation coefficient of elite trees in natural populations was 5.23%～37.42%. There were significant positive correlations (p < 0.01) between the transverse and longitudinal diameter of fruit, the weight of a hundred fruits, the thousand-grain weight of seed and the branch length of the current year, while negatively correlated with fruit shape index and fruiting density (p < 0.01). The thousand-grain weight was positively correlated with the transverse and longitudinal diameter of fruit, and the weight of a hundred fruits (p < 0.01). Fruit shape index, fruit stalk length, branch length of the current year and latitude factor were extremely significantly (p < 0.01) and negatively correlated; the transverse and longitudinal diameter of fruit, the weight of a hundred fruits, the thousand-grain weight of seed, the branch length of the current year and altitude factor showed a extremely significant (p < 0.01) and positive correlation. The results of principal component analysis showed that the comprehensive score of elite trees in Xixian population was the highest, while that of Wuzhai population was the lowest. The cluster analysis was carried out using Euclidean distance between populations, and the elite trees of 11 populations were divided into 4 groups. The results revealed the phenotypic traits of elite trees of H. rhamnoides subsp. sinensis in Shanxi did not form the rule of continuous variation, and had the characteristics of random variation.

Conclusion  There are abundant phenotypic variations among elite trees in natural populations of H. rhamnoides subsp. sinensis in Shanxi. The comprehensive traits of elite trees in Xixian populations are the best, which can be referred to as a key area for collection of elite germplasm resources of H. rhamnoides subsp. sinensis.