Plasticity of the Rice Genome: DNA Amplification in Cultured Cells

A message that geneticists and molecular biologists are increasingly addressing to plant breeders is that the plant genome is remarkably unstable. Plants of a population within a species can show karyotypic variations, with changes in chromosome number or with the appearance of supernumerary or β-chromosomes; but extensive submicroscopic variations, such as movement of transposable elements, chromosome rearrangements and gene amplification may also occur (Durrant 1974; Price et al. 1983; Walbot and Cullis 1983; Marx 1984).