Environmental and genetic factors influencing the spatial differentiation of wild Ziziphus jujuba var. spinosa quality in the eastern Foothills of the Taihang Mountains.

Ziziphus jujuba var. spinosa (Z. jujuba), an important medicinal and edible plant, is well-known for its sedative properties. However, the factors influencing spatial variation in Z. jujuba quality, as well as the relative contributions of environmental and genetic factors, remain poorly understood. In this study, the eastern foothills of the Taihang Mountains were selected as the study area. By integrating phenotypic and chemical analyses, SCoT molecular markers, and mixed-effect modeling, we systematically investigated the spatial differentiation of Z. jujuba quality and its influencing factors. The results showed that: (1) Z. jujuba quality exhibits pronounced spatial heterogeneity. Phenotypic traits varied significantly among production regions, with coefficients of variation ranging from 2.52% to 21.46%, and generally displayed a spatial pattern of "high in the north and low in the south." Among the chemical constituents, spinosin, 6'''-feruloyl spinosin, and jujuboside A showed a distribution pattern characterized by "high in the central and southern regions and low in the northern region," whereas jujuboside B decreased from south to north. (2) The percentage of polymorphic loci reached 79.43%, whereas overall genetic diversity remained at a moderate level. Genetic variation mainly originated from within populations (92.00%), indicating a genetic structure characterized by high gene flow and low differentiation. (3) The environmental factors explained a larger proportion of quality variation than genetic factors, with environmental and genetic factors accounting for 85.91% and 5.12%, respectively. Elevation and temperature were identified as the primary factors affecting leaf area, leaf nitrogen content, and jujuboside B, whereas kernel yield, single-seed weight, leaf water content, and 6'''-feruloyl spinosin were jointly associated with elevation, temperature, precipitation, soil factors, and genetic background. We established an association framework integrating environment, gene, and quality based on these findings, revealing a macro-level pattern of quality formation characterized by a greater contribution of environmental gradients, responsiveness of genetic background, and their combined interaction. Therefore, this study provides a scientific basis for understanding the geo-authentic formation processes and for the conservation and sustainable utilization of Z. jujuba resources in the Taihang Mountains.