Liquid Culture Systems for in vitro Plant Propagation

422 J.P. Ducos et al.
increase the volumes of bulk dehydrated embryos preventing them sticking
together and/or to paper disks or other types of supports.
In the case of species like carrot, with a very fast growth rate, a chemical
protection against micro-organisms for two or three weeks could be
sufficient for the somatic embryos to reach the photoautotrophic status
(Dupuis et al., 1999). For other species like coffee, for which the embryo-toplantlet
conversion is longer than two months, it will be difficult to maintain
phytoprotection and, consequently, embryo sorting and sowing might have
to be performed under aseptic conditions.
Such an approach (Ducos et al., 1998), based on desiccation, suggests a
new strategy for a complete automation of a large-scale handling delivery
process (up to 14,000 embryos sown per hour). Indeed, embryos can be
delivered onto sterile miniplugs wetted with sucrose–containing media as
containerized delivery systems (Timmis et al., 1991), pharmaceutical type
capsules (Dupuis et al., 1994) or cellulose acetate mini-plugs (Dupuis et al.,
1999). This would make the mass propagation via somatic embryogenesis
very close to the horticultural transplant industry and economically viable
for a large number of plant species.
Acknowledgements
The authors would like to thank D. Chenevotot (Clause Semences) who
has directly participated on the sowing experiments.
References
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