SOMATIC EMBRYOGENESIS ON THIN CELL-LAYERS OF A C-4 SPECIES, DIGITARIA-SANGUINALIS (L.) SCOP

Somatic embryogenesis was obtained from transverse thin cell layers (t TCLs) of Digitaria sanguinalis. tTCLs (0.2 -0.4mm thick, 1mm in diamet er) were excised from 4-week-old seedlings and placed onto Murashige a nd Skoog media supplemented with a varying concentration of 2,4-dichlo rophenoxyacetic acid (2,4-D) (from 1 mu M to 100 mu M) and sucrose (fr om 3% to 24%). Somatic embryos were obtained in the dark 7-10 days aft er inoculation from tTCLs excised at specific levels on the seedling a nd cultured in the presence of 2,4-D (5 mu M to 10 mu M) and sucrose ( 3 to 6%). The exposure of the tTCLs to light decreased the percentage of tTCLs forming somatic embryos. Viable plantlets were obtained 2 wee ks after transfer onto a cytokinin-containing medium.