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 micromolar Picloram and 9.5 micromolar kinetin or 10.8 micromolar or 45.25 micromolar 2,4-dichlorophenoxyacetic acid (2,4-D) and 9.8 micromolar N6-(2-isopentenyl) adenine (2iP). These explants after 12 weeks in darkness at 28 degrees C, produced embryogenic callus with very compact, pale yellow, nodular structures. Proliferation and maintenance of embryogenic callus was on MS basal medium with 2.26 micromolar 2,4-D, 0.83 micromolar kinetin and 2 micromolar abscisic acid (ABA), with a regular subculture every 3-4 weeks. Somatic embryo development was promoted by two months of culture on MS liquid medium enriched with 2 micromolar ABA, for torpedo stage development, then on liquid MS medium with 1 micromolar N6-benzyladenine (BA) and 0.46 micromolar kinetin, for shoot induction. Germinated embryos were transferred to basal media enriched with 0.45 micromolar BA and 0.06 micromolar naphthaleneacetic acid (NAA) for root and shoot induction and elongation. Viable plants were recovered on basal MS free of plant growth regulators (PGRs), but percentages of plant conversion have to be improved.