| In this work somatic embryos of saffron at different levels were evaluated. Plantlet regeneration was achieved in culture of mature saffron embryos via somatic embryogenesis. Embryogenic calli increased fresh weight fourfold when cultured under temporary immersion system compared to those held in solid medium. The ultrastructural study of the embryogenic nodules revealed a structure composed of cell clumps of meristematic morphology (E0), continued divisions formed globular embryos (E1), that were attached to the callus surface by a broad multicellular structure. Further development of the embryoids was characterized by the emergence of a shoot apical meristem (E2, monopolar stage) and subsequent differentiation of minicorm in the basal part of the embryo (E3, dipolar stage), when fully developed somatic embryos were separated from the embryogenic calli (E4, plantlets).; The level of lipid peroxidation and the response of the antioxidant enzimatic system were measured from each stage of embryos development. Changes in the polyamine levels of five polyamines (Dap, Put, Cad, Spd and Spm), free and conjugated, and the implication of polyamine metabolism in the differentiation and regulation of somatic embryogenesis in saffron have been analysed in the different stages of somatic embryogenesis. The changes in the pattern of antioxidant enzymatic activities (mainly SOD) and polyamines free and conjugated levels will be employed as markers for embryogenic process in saffron.; Finally preliminary studies of two systems of plant genetic transformation: Biolistic and transformation via Agrobacterium tumefaciens were studied. The best results to transformation of embryogenic callus of saffron were obtained when Agrobacterium tumefaciens was used. Protoplast were also transformed.; Further studies will follow to increase our knowledge about somatic embryogenesis. |
