Effective Use of Base-Specific Chemical Mutagens in Rice

The study of the use of base analogues and base-specific mutagens through treatment modifications in rice involved administration of the chemical mutagens of known specificty such as 5-bromouracil, 2-aminopurine, hydroxylamine, hydrazine, ethyl methane sulfonate and nitrosoguanidine along with L-canavanine sulfate (CANS), an inhibitor of histone synthesis at replication phase of DNA having Mitomycin-C+ Caffeine-induced lesions. The treatment response as measured by M, and M, indices revealed (a) material subjected to pretreatment with lesion-inducing agents proved physiologically more vulnerable to treatment with different mutagens along with CANS, (b) mutation frequency in the M₂ reflected an enhanced effect in the pretreated material subjected to mutagen treatment along with CANS and (c) the effectiveness and efficiency of treatment modifications appeared to vary with the inherent mutagenicity/toxicity of the mutagens.