ABSTRACT
Genetic variability is an essential component of any breeding program designed to improve the characteristics of crop plants. The variability generated by the use of a tissue culture cycle has been termed somaclonal variation by P. J. Larkin and W. R. Scowcroft. Two schemes, with and without in vitro selection, have been generally followed for getting somaclonal variation in crop plants. When attempting to produce somaclones for a new crop plant, some factors that are valid for both the schemes must be considered. Genotype can influence both frequency of regeneration and the frequency of somaclones. The variation observed among plants regenerated from cultured gametic cells is termed gametoclonal variation as compared to somaclonal variation that is somatic tissue derived variation. Gametes are products of meiosis, governed by Mendel’s laws of segregation and independent assortment. Gametoclones can be produced through the culture of either male or female gametic cells, or their derivatives.
