Liquid Culture Systems for in vitro Plant Propagation

334 F. Afreen et al.
the plant quality. In commercial micropropagation, labour usually
accounts for about 70 % of the total in vitro and ex vitro costs (Aitken-
Christie et al., 1991).
7. Conclusion
For the first time we have shown the photosynthetic ability of somatic
embryos of Coffea arabusta and successfully grew the somatic embryos
photoautotrophically. The important consequences of the study are that the
cotyledonary and converted embryos have photosynthetic ability and that the
light pre-treatment (PPF: 100 µmol m -2 s -1 ) speeds up the process. Therefore,
it is concluded that the cotyledonary stage is the earliest stage embryo,
which can be cultured photoautotrophically (in the absence of sugar in the
culture medium) to develop coffee plantlets. We hope that the
photoautotrophic culture system described here might also provide the basis
of a useful model for the in vitro propagation by somatic embryogenesis of
other important plant species.
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