Micropropagation and medicinal properties of Barleria greenii

1.4 Value of tissue culture
The application of tissue culture as a biotechnological tool in the conservation of
threatened economic plants has gained tremendous impetus in the last two
decades. The tissue culture technique is a powerful tool for plant germplasm
conservation and can be a viable alternative to conventional propagation of slow
growing species or species that produce recalcitrant or few viable seeds (ABOEL-
NIL, 1997). Rapid and mass propagation of plant species and their long-term
germplasm storage are achievable in a small space and short time, with no
damage to the existing population. Plant material can be produced throughout the
year without any seasonal limitation. Due to the aseptic nature of tissue culture
technique, large numbers of uniform and disease-free plants can be produced
from very small portions of the mother plant. The sterile nature of in vitro cultures
facilitates the exchange of germplasm or plant materials even at international level
(SALIH et al., 2001).
Furthermore, plant tissue culture systems often serve as model systems in the
study of physiological, biochemical, genetic and structural problems related to
plants (TORRES, 1989). The use of in vitro culture technique has found
applications in genetic breeding and improvement, production of new hybrids and
overcoming incompatibility during crosses. Somaclonal variation, often referred to
as „off-types‟ is sometimes considered to be an unwanted side-effect of in vitro
culture technique. However, depending on the research objective, this could be
advantageous in increasing the pool of variability. The variability can result in
superior plants or plants with adaptive advantage that can be selected and further
exploited in genetic improvement programs. Moreover, the control of chemical and
physical conditions of in vitro cultures makes it possible to optimize conditions
needed for enhanced production of secondary metabolites in target cells or tissues
(ABOEL-NIL, 1997). In vitro production of secondary metabolites, in turn, offers a
steady and reliable source of supply for pharmaceutical or nutraceutical industries
(GIULIETTI and ERTOLA, 1999).
7