Deciphering the effects of genotype and climatic factors on the performance, active ingredients and rhizosphere soil properties of Salvia miltiorrhiza

Abstract

Introduction: Salvia miltiorrhiza Bunge is an important medicinal herb, which is widely cultivated in most parts of China. It has attracted considerable attention because of its pharmacological properties and potential health benefits.

Methods: We used a field experiment to determine the effects of different genotypes and climatic factors on the performance (plant biomass, morphological parameters), active ingredients, rhizosphere soil physicochemical properties and microbial composition of S. miltiorrhiza at five cultivation locations.

Results: The results showed that these parameters were significantly different in the six different genotypes of S. miltiorrhiza from five producing areas. Genotype and soil physicochemical properties were the main factors affecting the growth traits of S. miltiorrhiza, while genotype, climate and soil physicochemical properties were the main factors affecting the content of active components of S. miltiorrhiza. Microbial phospholipid fatty acid analysis showed that the biomass of Gram-positive and Gram-negative bacteria was affected by the genotypes of S. miltiorrhiza plants, while the biomass of arbuscular mycorrhizal fungi, fungi, Gram-positive and Gram-negative bacteria was affected by climate factors.

Discussion: Based on the main results, DS993 was the most suitable genotype for S. miltiorrhiza in the five producing areas from the perspective of comprehensive growth traits and medicinal components, while DS993 and DS2000 were suitable for planting in Shandong province from the perspective of origin. DS996 is not suitable for all of the above production areas. These results are helpful to understand the ecological adaptability of different genotypes of S. miltiorrhiza resources, and to select appropriate S. miltiorrhiza genotypes for specific planting areas, so as to maximize yield and quality.

Keywords: Salvia miltiorrhiza; active compounds; climate; genotype; plant performance; soil microbial composition; soil physicochemical properties.

Figure 1

Plant growth parameters of Salvia miltiorrhiza genotype in different cultivation locations. Plant biomass (A); Plant height (B); Root diameter (C); Root branching number (D). BJ, Beijing; AH, Anhui; SD, Shandong; SX, Shaanxi; SC, Sichuan. Different letters above the error bars indicate significant difference at P < 0.05.

Figure 2

Active component contents of Salvia miltiorrhiza genotype in different cultivation locations. Tanshinone I content (A); TanshinoneIIA content (B); Cryptotanshinone content (C); Rosmarinic acid content (D); Salvianolic acid B content (E). BJ, Beijing; AH, Anhui; SD, Shandong; SX, Shaanxi; SC, Sichuan. Different letters above the error bars indicate significant difference at P < 0.05.

Figure 3

Rhizosphere soil physicochemical properties of Salvia miltiorrhiza genotype in different cultivation locations. Soil organic matter content (A); Soil pH (B); Soil sand content (C); Soil available N (D); Soil available P (E); Soil available K (F); Soil acid phosphatase (G); Soil alkaline phosphatase (H); Soil urease (I). BJ: Beijing; AH: Anhui; SD, Shandong; SX, Shaanxi; SC, Sichuan. Different letters above the error bars indicate significant difference at P < 0.05.

Figure 4

Rhizosphere soil microbial composition of Salvia miltiorrhiza genotype in different cultivation locations.Arbuscular mycorrhizal (AM) fungi biomass (A); Fungi biomass (B); G+ bacteria biomass (C); G- bacteria biomass (D). BJ, Beijing; AH, Anhui; SD, Shandong; SX, Shaanxi; SC, Sichuan. Different letters above the error bars indicate significant difference at P < 0.05.

Figure 5

Variation partitioning of climatic factors, genotype, soil physicochemical properties and soil microbial composition on the performance (A) and active ingredient (B) of S. miltiorrhiza. Climatic factors (including average temperature, mean temperature difference, soil mean temperature and mean rainfall); Genotype (including DS2000, DS992, DS993, DS994, DS995 and DS996); Soil physicochemical properties (including soil pH, organic matter, sand content, available N, available P, available K, acid phosphatase, alkaline phosphatase and urease); Soil microbial composition (AM fungi, fungi, G+ bacteria and G- bacteria).

Figure 6

Structural equation model (SEM) showing the causal relationships among climatic factors, genotype, soil physicochemical properties, microbial composition, growth parameters and active ingredients. The final model fitted the data well: maximum likelihood, X^{2 =} 105.89, df=18, P=0.001, GFI=0.925, AIC=167.229, and RMSEA=0.371. Solid lines and dashed lines indicate significant and non-significant pathways, respectively. The width of the solid lines indicates the strength of the causal effect, and the numbers near the arrows indicate the standardized path coefficients (*P < 0.05, **P < 0.01).