Genetic fidelity of organized meristem-derived micropropagated plants: A critical reappraisal |
| |
Authors: | Vijay Rani S N Raina |
| |
Institution: | (1) Laboratory of Cellular and Molecular Cytogenetics, Department of Botany, University of Delhi, 110007 Delhi, India |
| |
Abstract: | Summary The commercial multiplication of a large number of diverse plant species represents one of the major success stories of urilizing
tissue culture technology profitably. Micropropagation has now become a multibillion dollar industry, practised all over the
world. Of the various methods used to micropropagate plants, somatic embryogenesis and enhanced axillary branching have become
the principal methods of multiplication. Long-term benefits of this enterprise, however, lie in the production of clonally
uniform plants. The concept of genetic uniformity among micropropagated plants derived through organized meristems was exploded
by several convincing reports of the incidence of somaclonal variation at morphological, cytological (chromosome number and
structure), cytochemical (genome size), biochemical (proteins and isozymes), and molecular (nuclear and organellar genomes)
levels. Somaclonal variation is not limited to any particular group of plants; it has been reported, for example, in ornamentals,
plantation crops, vegetable and food crops, forest species and fruit trees. The upsurge of these reports, facilitated to a
large extent by the technical developments made in molecular biology, is a matter of great concern for any micropropagation
system. The economic consequences of somaclonal variation can be enormous in forest trees and woody plants, as they have long
life cycles. Therefore, somaclonal variation has to be dispensed with if large-scale micropropagation of diverse plant species
is to become not only successful but also accepted by end-users. In the light of the various factors (genotype, ploidy level,
in vitro culture age, explant and culture type, etc.) that lead to somaclonal variation of divergent genetic changes at the cellular
and molecular levels, genetic analysis of micropropagated plants using a multidisciplinary approach, especially at the DNA
sequence level, initially and at various cultural stages, is essential. The results obtained at early multiplication stages
from these tests could help in modifying the protocol/s for obtaining genetically true-to-type plants, and ultimate usage
by entrepneneurs without any ambiguity. |
| |
Keywords: | enhanced axillary branching genetic analysis micropropagation somaclonal variation somatic embryogenesis |
本文献已被 SpringerLink 等数据库收录! |
|