Investigation on seeds characteristics and establishment of aseptic cultural system for Rheum palmatum / 中草药

ABSTRACT

Objective: To study the seeds shapes and germination characteristics, construct aseptic seedlings and callus cultural system, and provide a basis for the rapid propagation and secondary metabolic regulation of Rheum palmatum. Methods: Ten batches of R. palmatum seeds were subjected to characteristic analyses from the aspects of size, purification, weights per thousand seeds, seeds vigor, germination rates, and germination energy. The optimum disinfection system for aseptic seedlings and the optimum hormone ratio for inducing callus were screened by orthogonal test. The content of ten active components in aseptic seedlings and calli were primarily evaluated by HPLC analysis. Results: There was no significant difference in the appearances of the ten batches of R. palmatum seeds from different regions. The content of moisture, seeds vigor, germination rates, and germination energy differed apparently. The germination characteristics in Hezheng and Weiyuan counties were the best. The best disinfection group for aseptic seedlings was the combination of 75% ethanol for 30 s with 10% hydrogen peroxide for 15 min. The optimum hormones for callus induction were 6-BA (1.0 mg/L) + KT (2.0 mg/L) + NAA (1.5 mg/L). Seeds treated with different disinfectants had no significant effect on the content of ten components in germinated aseptic seedlings (P > 0.05). Seven active components were detected in callus, which was significantly lower than that in aseptic seedlings. And the content of chrysophanol-8-O-glucoside was the highest in the callus. Conclusion: The seed characteristics from Hezheng and Weiyuan counties in Gansu Province were excellent by analyses of weights per thousand seeds, seeds vigor, germination rates, and germination energy. The aseptic seedlings and callus cultural system of R. palmatum were successfully established, laying a solid foundation for further study.