Functional traits mediate the effects of soil property on the growth performance of Ardisia gigantifolia cuttings

BACKGROUND: Understanding how soil types influence functional traits and growth performance is essential for effective plant cultivation and management. Ardisia gigantifolia (A. gigantifolia) is a rare traditional medicinal plant in China; however, the mechanisms underlying its growth responses remain poorly understood. This study utilized a pot experiment to investigate the effects of different soil types (humus, loam, and sand) on the functional traits and growth performance of one-year-old A. gigantifolia cuttings and to characterize the interrelationships among these factors. RESULTS: Compared to sand, humus soil significantly increased the height, as well as root and stem biomass of A. gigantifolia cuttings. In humus, the specific leaf area, leaf water content, root average diameter, root volume, stem length, and stem average diameter were significantly higher, whereas leaf dry matter content and the tissue density of leaves, roots, and stems were lower. Additionally, loam significantly improved the photosynthetic and pigment traits of the cuttings. Results from RDA and PLS-SEM demonstrated that the growth performance of A. gigantifolia cuttings is primarily and directly governed by root, stem, and leaf morphological traits, which also mediate soil-driven regulation. Root morphological traits, in particular, showed the greatest direct and indirect impacts, highlighting them as key potential indicators for predicting the performance of A. gigantifolia cuttings. CONCLUSION: This study demonstrates that the growth performance and functional traits of A. gigantifolia cuttings are modulated by soil properties, while organ morphological traits serve as reliable predictors of plant growth performance. Our findings provide a scientific foundation for the conservation of wild A. gigantifolia resources and the advancement of its sustainable industrial development.