Effect of N-methyl-N-nitro-N-nitrosoguanidine (NTG) on callus induction and survival rate on mature embryos of beans (Phaseolus vulgaris)

This research was conducted to study the effect of the chemical mutagen N-methyl-N-nitro-N-nitrosoguanidine on the percentage of callus induction and survival from mature beans embryos harvester cultivar. Seeds were treated with (0.2 or 0.4) millimolar of the mutagen NTG in combination with 0.0, 4 or 8% of ethanol, pH 5 ±2 0. for 24 h. Calli were induced on mature embryos by using MS medium with 0.5 mg/l of Benzyl adenine (BA), 1 mg/l Indole acetic acid (IAA) and 100 mg/l from each of Casein hydrolysate, Glycine, Asparagine, Tyrosine, and Myo-Inositol. Results showed that the hypocotyl surpassed the radical and the plume significantly in terms of survival reached 56.3%. Mutagen treatments showed asignificant effect on calli survival. Treatment with 8% Ethanol was lethal for all explants. While treatment with 0.4 mM NTG without Ethanol gaved the highest survival rate. The interaction between the treatments and the explants showed that the lowest survival percentage was which 8.8% that was for shoots treated with 0.2 mM of 4% Ethanol. Calli induced on hypocotyls treated with 0.4 mM NTG without Ethanol gave the highest fresh weight (347.2) mg while the lowest was (60) mg for calli induced on the radical treated with 0.4 mM NTG with 4% Ethanol. Moreover the highest dry weight was 22.5 mg for calli induced from hypocotyls treated with 0.4 millimolar NTG without Ethanol that was higher than the control 17.2 mg.The lowest dry weight obtained from calli induced on the radical treated with 0.4 mM NTG with 4% Ethanol was 3 mg. In conclusion the results showed that 0.4 mM NTG without Ethanol gave the highest survival rate and the highest fresh and dry weight for calli induced on the hypocotyl.