ABSTRACT
Chromosomal aberrations are a common occurrence in cell and tissue culture-derived calluses and their regenerants. In general, numerical and structural changes in chromosomes are attributed to spindle failure that causes endoreduplication, c-mitosis, nuclear fragmentation (amitosis), multipolar configurations, and lagging chromosomes. These changes are induced by media composition; age of the callus; nature of the callus, morphogenic versus nonmorphogenic; genetic background of the explants; and kinds of media, solid versus liquid (Bayliss, 1973, 1980; Evans and Reed, 1981; Wersuhn and Dathe, 1983; D’Amato, 1985; Ogura, 1990; Greier, 1991).
