Liquid Culture Systems for in vitro Plant Propagation

408 V.A. Savangikar et al.
In making cost calculations for the new and old model, following factors
are considered:
a) Repayment on capital assets considered at 20% each year. Capital cost in
new model being 25% of the capital cost for old model. It is presumed
that capital costs shall be similar in all countries.
b) Interest (per annum) on capital cost considered at 18% for developing
countries and at 4% for developed countries.
c) Depreciation on capital assets considered at 10% per annum.
d) Electrical consumption in new model, 33% of the old model.
e) Labour cost in developing countries is considered to be US $ 0.73 per
day (8 hour shift). Same in developed countries is taken to be US $ 40
per day (8 hour shift).
f) Costs in primary and secondary hardening are not included in cost
calculations as the location-specific differences, purpose specific
requirements/imperatives and species specific imperatives differ widely
and should be separately considered. Further, they are not a part of the
micropropagation model and should be assessed entirely separately.
3. Results and discussion
Production from the new model was more reliable than the old model in
terms of general vigor, contamination control and productivity.
Multiplication and rooting were also achieved simultaneously. The
multiplication culture lines initiated with use of old model medium in liquid
form (by omitting agar) lost vigor slowly with every subculture and despite
the application of visual indexing, were subject to high rates of
contamination and were discontinued eventually. The new model cultures
initiated with the new liquid medium and visual indexing were also subject
to fluctuating contamination incidents, but continued to be vigorous and
ultimately settled to a steady production rate. These stabilized lines are the
inputs for the work which has given the reported and analysed data. It was
also seen that success in primary hardening in plants derived from the new
model was better than the plants derived from the old model. This was
mainly due to the acclimatization effect, which the plants get already in
culture developmental stage in the new model i.e. development of hardiness
in leaves, stem and profuse rooting in culture itself as response to high
intensity of natural illumination of the cultures while they are undergoing
differentiation and multiplication while hanging in the greenhouse. Ziv
(1986) has also maintained that acclimatization in vitro is the best possible