Induction of Somatic Embryogenesis in Carrot by Osmotic Stress.

Abstract

Segments of cotyledon and apical tip taken from 1-week-old seedlings of Daucus carota L. were cultured for 3 weeks on hormone-free Murashige and Skoog's (MS) medium containing high amounts of sucrose (0.3-0.7M) and then transferred to the same medium with lower sucrose concentration (0.09M). Somatic embryos were formed from the segments 3 to 6 weeks after the transfer. On the other hand, hypocotyl segments given the same treatment did not produce somatic embryos. When the primary culture medium contained 0.61M mannitol and 0.09M sucrose, cotyledon segments and apical tip segments also produced somatic embryos when transferred to hormone-free MS medium with 0.09M sucrose. In all cases, somatic embryos were formed directly from the explants without visible callus formation.