Somatic embryos are characterised by the absence of any protection, a very low reserve level and a high water content. The effects on the respiration and the radicular elongation of somatic embryos of a non toxic and easy to use hydrogel, such as alginate, have been studied. Respiration or germination rates decreased with an increase in alginate concentration. When the encapsulated somatic embryos were placed in a liquid medium, there was very little difference between the germination rates observed at different alginate concentrations, either with or without an additional PEI layer. The effect of capsule concentration on germination rate was significatively different when the artificial seeds were growing on solid media. Besides the anoxic treatment upon encapsulated somatic embryos, storage for one month also decreased the germination rate.