ABSTRACT
Ferula gummosa Boiss. a highly valuable medicinal plant which naturally propagates in very limited areas of the Middle East with specific environmental conditions. The production of Ferula gummosa somatic embryos and the karyological analysis of somatic seedlings were the purpose of this study. High frequency indirect embryogenesis was induced in callus derived from zygotic embryonic axes. Embryogenesis was obtained when callus tissues were placed onto an agar induction Murashige and Skoog medium with 1-naphthalene acetic acid and after the transfer of the cultures in a thermoperiod regime of 16 h, 19 degrees C/8 h, 7 degrees C under photoperiod of 16 h light/8h dark. Embryogenic callus tissues were maintained by subculture on induction medium. Globular proliferation was achieved with suspension culture in the Murashige and Skoog medium added with 1-naphthalene acetic acid or 2,4-dichlorophenoxyacetic acid for two weeks. Maturation of embryos and development of plantlets arose on the induction agar medium, but was better after transfer into the hormone free Murashige and Skoog medium. However, the level of abnormal embryos was high. Direct embryogenesis was obtained from somatic seedlings. The best results were obtained from hypocotyl explants. Embryo induction was achieved by two week culture of the explants in 2,4-dichlorophenoxyacetic acid liquid medium; somatic embryo growth and maturation was recovered on the hormone free medium. High level of abnormalities was recorded in the culture. Karyological analysis showed a high incidence level of cytochimerism in somatic seedlings with chromosome stickiness, polypoidy and aneuploidy in metaphase cells of the same root tip. The frequency of these karyological changes varied with the type of somatic embryos with regard to morphological abnormalities. Normal and abnormal rooted somatic seedlings were able to grow until production of the first leaf and then entered dormancy in the same manner as zygotic plantlets.
