The aim of this study was to characterize drought tolerance of 20 common bean genotypes using some biochemical markers for oxidative stress. 10 common bean cultivars (9 Bulgarian and a Mexican - BAT 477) and 10 mutant lines M(19–20), previously obtained by us after the treatment of seeds from Dobroudjanski 2 and Dobroudjanski 7 cultivars with ethyl methan sulphonate (EMS) and N-nithroso-N-ethyl urea (NEU) were used in this investigation. BAT 477 was chosen as a control and it was presented in unique cluster group. Three biochemical markers – malondialdehyde (MDA), hydrogen peroxide (H2O2) and proline were analyzed. The results were statistically elaborated by mono-, bifactorial ANOVA and cluster analyses. Our preliminary results demonstrated that to obtain more valuable information, concerning drought tolerance of both common bean cultivars and mutant lines, MDA, H2O2 and proline should be used as early warning markers. Genotypes studied could be of interest in future investigations being a geneplasme source of common bean drought tolerance.
