Variation in seed germination, embryo structure and seedling root traits in micropropagated plants of rhubarb ( Rheum rhaponticum L.).

摘要

Micropropagation has been successfully applied to regenerate planting materials of rhubarb (Rheum rhaponticum L.). Variations in seed germination, seedling root development and embryo structure of micropropagated rhubarb 'PC49' were investigated. Seeds from micropropagated plants showed a much reduced germination rate (11.8%) compared to conventional seeds (74.8%). Altered embryo structures, including "bowl shape", "spoon-shape" and "Y-shape" embryos, were found only in seeds derived from micropropagated plants. Additionally, the seedling root traits from micropropagated plants showed significant differences in both main root length and branch root number compared to seedlings of conventional seeds. Micropropagated seedlings developed a mean 22.5 mm main root length and 12.8 branch roots, compared to 35.1 mm root length and 17.4 branch roots from conventional seedlings. This study provides further evidence of somaclonal variation in micropropagated rhubarb 'PC49'.