The investigation was conducted with 174 free threshable and 176 non free threshable mutant lines. Among free threshable mutants, physical irradiation with gamma rays showed high effect in getting more number of spot blotch resistant lines (70.15%) in M3 generation. In M4 generation, EMS treated mutant lines have given more number of spot blotch resistant lines (52.11%). Irradiation treatment on DDK-1001 has given highest effect in getting more number of resistant lines both in M3 and M4 generation. Among free threshable mutant lines 23 have shown resistance both in M3 and M4 generation....