Abstract
The nuclear modification for prolonged subculture was studied with rice callus tissues using three varieties.
The nuclear size of Tan-ginbozu callus tissues, a dwarf variety in Japonica type, increased from 6μ to 7μ in their mean diameter after about one year of subculture. The cells having the giant nucleus above 11μ were observed. The elucidation of the histological steps of the nuclear modification ascertained that the enlarged and vacuolated cells containing the giant nucleus are enveloped with the cells having nuclei of ordinary size. However, the cells of Te-Tep and Konansen, tall varieties in Indica type, retained their characteristic morphology of nuclei for prolonged periods of culture.
