A multi-step process by which plant somatic embryos can be sown and germinated
ex vitro using conventional seeding equipment, growing mixes, and plant propagation
environments. The process most preferably comprises the steps of: placing a somatic
embryo on or within a three-phase substrate, the phases comprising solid, liquid
and gas phases, placing the substrate containing a somatic embryo into an environmentally-controlled
plant-growing environment in which at least one environmental factor (i.e. moisture
level within the three-phase substrate, atmospheric humidity, temperature, nutrients,
ambient light intensity and diurnal photoperiod) may be controlled and manipulated,
manipulating at least one of the environmental factors to enable and facilitate
germination of the somatic embryo, and applying water and/or nutrient solutions
at regular intervals, the intervals preferably ranging from 1 minute-24 hours,
to the surface of the substrate in the form of microdroplets, preferably for a
period of time ranging between 3 to eight weeks, such that somatic embryo imbibition,
germination, growth and development occur. The process can be practiced in non-sterile
conditions with "naked" fresh and/or HRHT-treated and/or desiccated embryos, i.e.,
non-encapsulated or otherwise uncoated embryos, and does not require the use of
aseptic techniques or sterilized media or equipment.