Abstract:

Sinopodophyllum hexandrum is a rare and endangered medicinal plant. This study aimed to compare leaf traits, bioactive components and metabolic profiles in roots between wild population and ex-situ conservation population in Liupan Mountain, providing a theoretical basis for the resource protection and reintroduction of S. hexandrum. Rhizosphere soils, leaves and roots were collected from two-year-old S. hexandrum plants in both environments. Soil physicochemical properties, leaf functional traits, photosynthetic parameters, ecological stoichiometry, nutrient resorption efficiency and the content of medicinal composition and metabolomics in root were assessed. The results showed that soil in wild distribution areas contained significantly more organic carbon, total nitrogen, alkali-hydrolyzable nitrogen and available potassium, while pH was lower than in ecological planting area soils. No significant differences were observed in soil water content, total phosphorus or total potassium. The dry matter mass, C/N, C/P and N/P in the leaves and kaempferol content in the roots of two-year-old S. hexandrum in ex-situ conservation population were significantly higher than those of wild population. However, their leaf length, width, surface area, content of C, N and P elements in leaves, nutrient absorption efficiency, content of root podophyllotoxin and 4’-demethylated podophyllotoxin were significantly lower than those of wild population. Photosynthetic indices (net photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO₂ concentration), leaf relative water content and quercetin content in roots showed no significant difference both populations. There were a total of 3406 metabolites in the roots of S. hexandrum of ex-situ conservation population and wild population, of which 1136 metabolites showed no significant differences, some metabolites related to the synthesis of medicinal ingredients such as podophyllotoxin showed significant differences. The leaf functional traits, ecological stoichiometry characteristics and medicinal ingredient content of S. hexandrum of ex-situ conservation population are different from those of wild population, which may be related to environmental factors such as soil factors, rainfall and temperature in its distribution area. The results of this study can provide a theoretical basis for the optimization of ex-situ conservation habitat, the stable regulation of medicinal components and the regression and reconstruction of wild populations of S. hexandrum.

Key words: Sinopodophyllum hexandrum, ex-situ conservation, leaf functional traits, pharmacological ingredients, ecological stoichiometry characteristics