CYTOGENETICS OF MUTANTS IN RICE

A study was conducted on morphological and cytogenetic changes induced by gamma rays, EB, NMU and SA on 3 indica cvs of rice viz., Aditya, Annada and IR-36. The main objectives were to assess the relative effectiveness and efficiency of the mutagens employed and to evaluate the mutational response of cvs for induction of viable morphological, cytogenetic and chlorophyll mutants. Seedling and mature plant characters, types of cytological aberrations in M1, frequency and spectrum of chlorophyll and other morphological mutants in M2 were studied. Cytological aberrations were detected in treatments with gamma rays and SA only. Varietal differences were observed reflecting on their genetic diversity. In all the cvs higher frequency of chlorophyll mutants were observed with SA treatments. The true breeding dwarfs are of considerable interest from breeding point of view. Early flowering mutants with improved seed set in all the cvs appear to be suitable for commercial utilization. This monograph is useful to the researchers in the fields of genetics, plant breeding and biotechnology.