Regeneration of diploid annual medics via direct somatic embryogenesis promoted by thidiazuron and benzylaminopurine

The development of a simple and rapid procedure for direct somatic embryogenesis from wild Medicago spp. (M. truncatula, M. littoralis, M. murex, M. polymorpha) has exploited various explants including meristematic zones. Phytogel-solidified medium supplemented with thidiazuron or 6-benzylaminopurine at different concentrations effectively promoted this process. The first somatic structures emerged within 20 days of culture initiation. Histological analyses confirmed the nature of the directly formed embryos. Secondary embryogenesis was also observed. Cuttings of clusters of primary and secondary embryos were used for cyclic production of new embryo generations. Regenerated plants with well-developed root systems on medium with reduced levels of macroelements and sucrose were easily adapted to a greenhouse.