This work aimed at evaluating the effect of different NaCl concentrations (0, 68, 137 and 205 mM) in two maize (Zea mays L.) genotypes (W64Ao2 and Arizona 8601) callus cultures in N6 medium, supplemented or not with 6.0 mM proline. Treatments consisted of the combinations of the four NaCl levels with the two-proline levels under 4x2 factorial. Treatments were maintained for 60 days with subcultures at 20 days each. Relative growth rate, endogenous free putrescine, spermine, spermidine, proline and others amino acids were evaluated at the end of the experimental period. Proline addition improved callus growth in both genotypes in the control treatment and reduced deleterious effects in the highest salt level (250mM NaCl). W64Ao2 callus growth rate was higher than in the Arizona 8601 probably due, in part, to the higher proline accumulation and the maintenance of polyamine metabolism in those calluses.
Aminoacids; poliamines; salinity; Zea mays
