A comprehensive comparison on root yield and content of polysaccharides and alkaloids from ten germplasms of Isatis indigotica Fort. in two growing areas

In order to promote the application of high-quality varieties and explore the diversity of cultivated resources of Isatis indigotica Fort., the source of medicinal Banlangen, 10 germplasms were planted in Heilongjiang (HLJ) and Shanxi (SX) provinces to analyze two-year agronomic traits, yields and active ingredient contents in this study. The results showed that germplasm no. 2 had the highest yields in both HLJ (236.54 kg/mu) and SX (368.68 kg/mu), and it had the highest Epigoitrin (RSG) content in HLJ in 2020 (0.8946 %). In addition, the polysaccharide (IRPS) content of germplasm no. 2 was the highest in HLJ (up to 39.100 mg/g), and ranked second in SX (30.767 mg/g). It was the only germplasm with IRPS content that exceeded 30 mg/g in both areas. The yield and RSG content of germplasm no. 6 was slightly lower than that of germplasm no. 2. The germplasms no. 2 and 6 had remarkable advantages in yield and active component content which were worthy of promotion as excellent cultivars in planting industry. Germplasm no. 5 and 10 had advantages in root width and IRPS content, respectively, which could be used as breeding germplasms. Screening germplasm with excellent traits and promoting its cultivation will help to ensure the quality stability of medicinal materials, and to improve economic efficiency of Banlangen production.