SWELLING OF PLANT CHROMOSOMES BY EXPOSURE TO HIGH-INTENSITY INCANDESCENT LIGHT

Although our previous studies indicated that exposure of animal chromosomes to high-intensity incandescent light produced distinct C-banding in some species, the method produced only faint C-banding in plant chromosomes. Exposure of plant chromosomes to high-intensity incandescent light for one hour at pH 6.8, however, produced a novel phenomenon which we refer to as <<chromosome swelling>>, which was not seen in animal chromosomes. These findings are most likely due to structural differences between plant and animal chromosomes. The process of chromosome swelling may facilitate future studies of plant chromosome structure, as well as the analysis of plant chromosome aberrations and fragile sites.