EFFECT OF GAMMA IRRADIATION,METHYL METHANE SULPHONATE AND THEIR COMBINATIONS ON GROWTH, FLOWERING AND INDUCED VARIABILITY IN Tagetes erecta, L.

Seeds of Tagates erecta. were irradiated with different doses of gamma-rays ( 0,5,10 and 15 kr.),  other part of seeds was treated with different levels of MMS ( 0.0, 0.1, 0.2, 0.3,0.4, 0.5 and 1.0%) .  Also there were  combined treatments between the two mutagens..
            Intermediate doses of gamma-rays (10kr.) gave the lowest germination percentages in both  seasons. There were no significant differences among the different treatments of gamma-rays in M₁- and M₂-generations of both seasons- on the plant height. All doses of gamma-rays delayed the flowering date in all generations for both seasons. Except the M₂-generation of the first season, gamma-rays showed significant effect on the number of flowers in all generations. 5 kr. in the M₁-generations of both seasons had the largest average number of inflorescences, but in the M₂-generation of the second season,  it had the lowest one. Low doses of gamma-rays (5 kr.) caused smaller flowers than normal in the M₂-generation of the first season.
          Low concentrations of MMS (0.1%) caused a stimulating effect on seed germination in both generations. But the high concentration (1.0%) caused death of seeds ( lethal dose). Different treatments of MMS showed no significant differences in M₁-generation in both seasons on the plant height.  High concentration of MMS (0.5%) caused albino chlorophyll mutant in the seedlings in the M₂-generation of the first season. Low concentration of MMS (0.2%) delayed the flowering date in all generations with one exception in the M₂-generation of the second season, where 0.5% was the latest one. Low concentration of MMS (0.1%) gave the largest flower number in the M1-generation for both seasons but the high concentration (0.5%) gave the  largest one in the M₂-generation of the first season.
        The combined treatments were more efficient than the single ones on seed germination . The lethal dose ranged between the doses 1.0% MMS + 0. Kr. gamma-rays to 1.0% MMS + 15 kr. gamma-rays.  Generally, 0.5% MMS + 5 kr. gamma-rays gave the largest number of inflorescences in all generations except in the M₂-generation of the second season. Many different petals shape were obtained from the different combined treatments. Seeds of M1-plants treated with 10 kr. + 0.3% resulted in a mutation in stalk shape.