Somaclonal Variations and Their Applications in Medicinal Plant Improvement

Abstract

Plant tissue culture is an important tool for various investigations in many plants including medicinal plants. Different techniques are used to in vitro cultivate medicinal plants for mass propagation, conservation, and secondary metabolites production. They include micropropagation, axillary bud, shoot culture, root, and callus culture, organogenesis, somatic embryogenesis, and cell suspension culture. For the production of phytochemicals, cell suspension and callus cultures are most preferred followed by root and shoot cultures and somatic embryogenesis. However, plant tissue culture may generate somaclonal variations as a result of gene mutation and/or changes in epigenetic marks, particularly with highly differentiated explants and callus stage passage. On one hand, the occurrence of somaclonal variation may be an obstacle for both in vitro propagation and germplasm conservation, while it is exploited in many crop plant improvements on the other hand. In the present chapter, possible somaclonal variation following medicinal plant tissue culture and their consequent implication in the regulatory network of secondary metabolites production are presented.