Applications of Cell Culture

Mutant Selection
An important use of cell cultures is in mutant selection in relation to crop improvement. The frequency of mutations can be increased several fold through mutagenic treatments, and millions of cells can be screened. Since selection of mutations will be exercised at cellular level, no chimeras will be obtained, which is sometimes a drawback of mutation breeding methods, where mutants are selected at the level of whole plants. Further, if haploid cells (like microscopes) are used for cell culture, the problem of dominance not permitting the expression of mutations in M1 generation is also automatically overcome. A large number of reports are now available where mutants have been selected at the cellular level. The cells are often selected directly by adding the toxic substances against which resistance is sought in the mutant cells.

Salt tolerant and cold tolerant cell lines have also been isolated in the genus Nicotiana. Auxotrophic mutants are selected by microbial methods using the minimal medium, where only prototrophs will grow. The cell lines will be grown first on complete medium and then on the minimal medium. Lack of growth on minimal medium will suggest the presence of and auxotroph, which can be grown on supplemented media to identify nutritional deficiency. The selected mutant cells need to be grown into whole plants in the field, which will be multiplied and tested for the mutant phenotype. This mutant phenotype may or may not express at the level of whole plants. If it expresses in whole plant, its genetics can be studied using conventional methods of genetics.