Mutagenic potential of cadmium nitrate [Cd(NO3)2] and ethyl-methane sulphonate [EMS] in quantitative and cyto-physiological characters of Capsicum annum L. cultivars

Abstract

Mutation breeding sustained food demand of the world through the introduction of desirable changes in the plants at the phenotypic as well as genotypic level. The study was primarily based on the aspects of beneficial and harmful effects of cadmium nitrate [Cd(NO 3 ) 2 ] and ethyl-methane sulphonate (EMS) as mutagenic agents in cyto-physiological and quantitative characters in Capsicum annum L. cultivars. The chilli seeds were treated with different concentrations of Cd(NO 3 ) 2 (0.01%, 0.02%, 0.03%, 0.04%, and 0.05%) and different concentrations of EMS (0.10%, 0.25%, 0.50%,0.75%, and 1.00%) alone to induce the cyto-physiological and quantitative changes and also to assess the mutagenicity of both chemicals. The results were revealed that Cd(NO 3 ) 2 has more toxic effects even in low concentrations than EMS with high concentrations. A high frequency of distortive chromosomes was found under treatment of Cd(NO 3 ) 2 while EMS revealed the least chromosomal effects. The physiological parameters were also recorded and results shown a decreasing trend in all the characters. The yield and yield contributing characters were recorded to moderate with increasing concentrations of Cd(NO 3 ) 2 while in EMS treated it decreased with increasing concentrations and showed some positive effects. The stomata aperture is reduced to close at high concentration of Cd(NO 3 ) 2 while EMS has little effect on stomata movement. The proline content and superoxide dismutase (SOD) enzyme activity increased with the increasing concentration of Cd(NO 3 ) 2 , whereas a small increment in proline content and SOD activity also was reported in EMS at higher concentrations. The mutagenic efficiency of a chemical mutagen can be calculated by determining the effectiveness of inducing the trait of interest in chilli crop plants having a narrow genetic base. The following changes in chilli cultivars can be further used to improve the quantitative and physiological characters through the plant breeding programs.