Somatic embryogenesis in Canary Island date palm

Zygotic embryo and shoot tip explants of Phoenix canariensis were cultured on MS (1962) basal medium supplemented with 100 mu M Picloram and 9.5 mu M kinetin or 10.8 mu M or 45.25 mu M 2,4-dichlorophenoxyacetic acid (2,4-D) a nd 9.8 mu M N-6-(2-isopentenyl) adenine (2iP). These explants after 12 week s in darkness at 28 degrees C, produced embryogenic callus with very compac t, pale yellow, nodular structures. Proliferation and maintenance of embryo genic callus was on MS basal medium with 2.26 mu M 2,4-D, 0.83 mu M kinetin and 2 mu M abscisic acid (ABA), with a regular subculture every 3-4 weeks. Somatic embryo development was promoted by two months of culture on MS liq uid medium enriched with 2 mu M ABA, for torpedo stage development, then on liquid MS medium with 1 mu M N-6-benzyladenine (BA) and 0.46 mu M kinetin, for shoot induction. Germinated embryos were transferred to basal media en riched with 0.45 mu M BA and 0.06 mu M naphthaleneacetic acid (NAA) for roo t and shoot induction and elongation. Viable plants were recovered on basal MS free of plant growth regulators (PGRs), but percentages of plant conver sion have to be improved.