Liquid Culture Systems for in vitro Plant Propagation

406 V.A. Savangikar et al.
together even by applying a rubber band around it or by applying a clip.
Length and width of the bags and volume of the medium used can be varied
depending upon the size of the inoculum.
For the dimensions of the bags given above, single plants were
inoculated, which transformed into a bunch of plants in four to six weeks
depending on the ambient temperature. The lower the ambient temperature,
the more the time required to come to full development.
Inoculated bags were tied in a group of 18 bags in each taking care to
avoid overlap, on a thick rope in the greenhouse. While hanging, the bags
may remain horizontal, or usually, medium accumulates in one of the
corners of the bag. In a greenhouse of 28 m length and 25 m width, 6 meter
height at center, 100,000 bags were accommodated. Mutual shading of the
bags was avoided as far as practically possible.
Mother cultures to be used in the new model were adapted to a
proprietary medium with better fine-tuning of the ingredients and new
conditions of incubation for three passages and were subjected to visual
indexing. As a matter of policy, antibiotics, high levels of cytokinin and
2,4-D are not used at any stage in the medium. Multiplication cultures were
also initiated using medium of the old model in liquid form (by omitting
agar) and cultures incubated in old model as well as in the new model.
The location of the laboratory is near 20 o North and 80 o East in central
India. Climate of the location of the facility is semi-tropical, hot and humid.
In hot days in May, ambient temperature reaches up to 43 o to 46 o C for few
hours in the day. In winter months, minimum temperature reaches 6 o C
approximately. Fan-and-pad cooling is needed for about four months per
year, in October, March, April and May, when maximum ambient
temperature crosses 36 o C in the afternoon. For most of the days in monsoon
months of June to September, sky is overcast with clouds. In rest of the days
in a year, the sky is clear with full sunshine. Ambient humidity in monsoon
remains between 70 to 90%, in October it remains between 50 to 65%, in
winter months of November to January it remains between 50 to 80% and in
other months, it comes down sharply and remains between 10 to 30%.
Primary hardening is usually carried out between August to December, when
humidity inside the polyhouse is maintained between 70 to 90% by
intermittent misting.
The production data maintained in regular course for operations in old
and new model was used to compare the practical efficiencies of both
models. The data selected for comparison was based on the steady state
period of large-scale operations with the use of 6 laminar clean air flow
stations in the new model in a one shift operation and 10 laminar clean air
flow stations in old model in a two shift operation, taking the average over
the period. From the old system data, an 11 week period was selected for