Quantity of epicuticular wax on sorghum leaves (Sorghum bicolor L., Moench) and its contribution to water stress resistance

Abstract

This study determines the effect of the amounts of CCE on leaf area and aerial biomass production of grain sorghum under irrigation on drought conditions. The previous characteristics under irrigation and drought for four sorghum isolines for contrasting epicuticular wax load on the leaves were evaluated. Line Bm-22 had the lesser wax quantities and the smaller leaf area values, biomass and grain yield under both conditions than the rest of the isolines, and the greater reductions of these parameters under drought. On the other hand, line P-954035 showed the highest values of leaf area, biomass and grain yield than the rest of the lines. No meaningful correlation was found between the CCE load and the rest of the variables, except for grain yield which was significantly interrelated under drought (r=0.48{*}). It was concluded that small variations in the epicuticular wax load of sorghum do not bring about significant changes in the evaluated characteristics and that genotypes with high CCE wax load have greater drought resistance.