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

Abstract

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 M1generations 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 gammarays (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.

The Influence of Diethyl Sulphate on Vegetative, Flowering Growth,Chemical Composition and ISSR Genetic Markers of Celosia argentea L. Plants

“…On the other hand, elevated concentrations seemed to inhibit the cell growth, decrease growth rate, and delay the flowering date, as reported by Badr et al (2000) and El-Nashar (2006).…”