Somatic embryogenesis:: A valuable alternative for propagating selected robusta coffee (Coffea canephora) clones

The behavior of four coffee (Coffea canephora cv. Robusta) clones was evaluated in this work to define the conditions that would allow somatic embryogenesis to be induced at different seasons of the year. The objective was to have an adaptive methodology for in vitro propagation of these four coffee clones that were selected for their agronomic characteristics. The use of 2,4-dichlorophenoxyacetic acid and Picloram in the culture medium at concentrations between 2.07 and 4.14 muM resulted in high-frequency somatic embryogenesis when leaves were collected between April and June for genotype C-R, and between April and July for M-229. Callus from 28 to 35d of induction showed better results throughout the whole regeneration process, particularly in liquid medium. There was a clear difference in the behavior of the clones evaluated.