Abstract:Inorganic elements in medicinal plants not only affect the growth and development of medicinal plants, but also are important constitutes of its active ingredients. The present study examined the content and variability of inorganic elements in Scutellaria baicalensis and its relevant rhizosphere soils, as well as the plant's absorption characteristics for various inorganic elements, to explore the relationship between inorganic elements in rhizosphere soil and inorganic elements in roots. A total of 92 S. baicalensis plant and its 92 relevant rhizosphere soil samples, derived from 16 different origins across China, were employed in this experiment. Ten different inorganic elements were detected in the plant samples and the analyses of their corresponding rhizosphere soils. The inorganic element contents of plants from different origins and their corresponding rhizosphere soils varied significantly, and the variation among soils of different origin was much greater than in plants. The ANOVA showed that, in addition to Zn, the contents of other inorganic element in the samples and their corresponding rhizosphere soils were significantly different according to origin. For example, the Cr contents in the samples from Durbat, Heilongjiang were significantly higher than those of samples from other origins and nearly eight times greater than the study average. The rhizosphere soils from Weichang, Hebei and Chicheng, Hebei, contained significantly more Cr, Fe, K, Mn, and Sr than did samples from other areas. The coefficients of variation for Cr, Fe, K, Mn, P and Sr in the plant samples from the 16 origins were significantly greater than those in the rhizosphere soil. However, no significant differences were observed between the coefficients of variation of the inorganic elements for their overall distribution in the plant samples and in the corresponding rhizosphere soils. Furthermore, the content of Mg (9 level) in S. baicalensis (9) was relatively higher than in other plants, while the P (1 level), K (2 level), and Mn (3 level) contents were relatively lower. S. baicalensis also showed a strong concentration of Sr (with an enrichment coefficient of 3.52) and a weak concentration of P (with an enrichment coefficient of 1.27). At the same time, the enrichment coefficient of each inorganic element varied significantly according to origin. Additionally, we obtained the fingerprint spectra of the inorganic elements of S. baicalensis using inorganic element distribution curve analysis and filtered out the characteristic inorganic elements using principal component analysis. Mg, K, Ca, Fe and Zn were the characteristic inorganic elements of S. baicalensis, while Ca, K, Mg, Mn and Zn were the characteristic inorganic elements in the rhizosphere soil of S. baicalensis. Overall, the study showed that the absorption capacity of S. baicalensis for each element varied with origin and that the absorption capacity for each inorganic element was tied to the plant's growth demands and the absorption characteristics of the element. These results also suggested that a correlation existed between the absorption of inorganic elements and the inorganic elements in the rhizosphere soil. This study provided a comprehensive understanding of the geographic variation of nutrient quality for S. baicalensis and a theoretical basis for choosing appropriate planting habitats.