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) and 9.8 mu M N-6-(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 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 liquid 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 enriched with 0.45 mu M BA and 0.06 mu M 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.