SOMATIC EMBRYOGENESIS IN PEANUT (ARACHIS-HYPOGAEA L) - STIMULATION OFDIRECT DIFFERENTIATION OF SOMATIC EMBRYOS BY FORCHLORFENURON (CPPU)

The ability of forchlorfenuron (CPPU), a substituted phenylurea compou nd, for inducing somatic embryogenesis in peanut (Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Emb ryogenic response was dependent on applied CPPU concentrations. Exposu re of seedlings for only two days to CPPU induced somatic embryogenesi s, but the most effective treatment was to induce seed germination on media supplemented with either 2.5 or 4.0 mu M CPPU and to maintain th e seedlings on the same medium. Number of somatic embryos and the freq uency of embryogenesis was higher for younger seedlings (up to 9 days) , regardless of the CPPU concentrations and seedlings older than 21 da ys failed to produce somatic embryos. Removal of cotyledons from the s eeds drastically reduced the embryogenic potential of the seedlings. S omatic embryos developed into whole plants following their separation and subculture on a medium lacking growth regulators. The induction of somatic embryos using CPPU as a sole growth regulator may provide a u seful system to study the role of this compound in plant morphogenesis .