CHEMICAL MUTAGENESIS IN MANHAR VARIETY OF RICE (ORYZA SATIVA L.)

Abstract

Treatments with mono- and bifunctional ethylated (NEU, NDEU) and methylated (NMU, NDMU) urea and ethyl methane sulphonate (EMS) in Manhar, an early maturing (120 days) variety of indica rice reduced the germination, seedling survival, pollen fertility and spikelet fertility percentage in Mt generation. NEU produced the highest frequency of viable mutations in the M% generation, on the basis of segregating M% progenies as well as mutants/lOO M% seedlings. Treatments with NEU (6 h) also produced the widest spectrum and maximum relative frequency of viable mutations in M% generation. The relative mutation frequency of monofunctional compounds NEU and NMU was larger than their respective bifunctional compounds NDEU and NDMU. The most effective and efficient mutagens were 0.010/. NMU and 0.050/. NDEU, respectively.