Somatic embryogenesis of maize hybrids: histological analysis

The immature zygotic embryos of reciprocal maize hybrids (CHI-31 x GF(1) and CHI-31 x GE;?) were used as the initial material for induction of somatic embryogenesis in vitro. Histological analysis of somatic embryogenesis revealed high developmental variability. The arising formations were classified into 5 groups: A) somatic embryos phenotypically similar to zygotic embryos, B) polyembryos, C) formations with radicle but without meristematic plumule, D) formations with radicle without differentiated plumule, and E) formations with plumule without radicle. The formatioms A and B regenerated directly into plants. Plant regeneration from formations E required preculture on the rooting medium. Formations C and D failed to develope into plants possibly because of early loss of meristematic cell character during the embryo axis differentiation. The reverse sequence of radicle and plumule differentiation in somatic embryos in comparison with zygotic ones was noted. The epigenetic character of the scutellum, coleoptile, coleorhiza and leaves primordia development was discussed.