BIOCHEMICAL-MECHANISM IN GLOSSY SORGHUM LINES FOR RESISTANCE TO SALINITY STRESS

In this study 17 glossy sorghum genotypes were evaluated in pots filled with white perlite to determine their resistance to salinity stress. We used 0.25 M sodium chloride solution for salinity treatments and distilled water for the control for a period of 25 d after emergence. The variables measured were: seedling height, root length, root, shoot and total dry mass of the plants. Highly significant differences were found among genotypes and among treatments for all these traits. Tolerance indice were calculated, and on the basis of these results, the genotypes IS-22201 and IS-4473 were selected as resistant and the genotypes IS-5643 and IS-1096 as susceptibles to salinity stress at the seedling stage. In the second phase the four genotypes selected were evaluated with salinity treatments of 0, 0,10, 0.15, 0.20 and 0.25 M sodium chloride. In this experiment the fluctuations of total chlorophyll, hydrocyanic acid, and epicuticular wax in the leaves, and proline content from the root, were determined. There was a marked relation between concentrations of these compounds and the salinity levels used.