Induced chlorophyll mutations. I. Mutagenic effectiveness and efficiency of EMS, HZ and SA in mungbean

Abstract

A systematic and comparative study on the frequency and spectrum of chlorophyll mutations induced by ethylmethane sulphonate (EMS) — an alkylating agent, hydrazine hydrate (HZ) — a base analogue and sodium azide (SA) — a respiratory inhibitor, was carried out in two mungbean varieties, namely, PDM-11 and NM-1. Awide spectrum of chlorophyll mutants was obtained in the M2 generation. All these chlorophyll-deficient mutants were lethal except maculata, viridis and virescent. Chlorina followed by xantha types were predominant in both the varieties. EMS treatments induced the highest frequency of chlorophyll mutations followed by HZ and SA. The frequency of chlorophyll mutations was dose-dependent and increased with the mutagen concentration. Based on effectiveness in both varieties, the order of mutagens was HZ > SA > EMS. Two criteria viz., pollen sterility (Mp/S) and seedling injury (Mp/I) were taken into consideration to determine the efficiency of the mutagens. EMS was found to be the most efficient mutagen followed by HZ and SA. Moderate concentrations of the mutagens were the most effective and efficient in inducing mutations.