Evaluation of the anti-rust enzymatic activity in Stylosanthes guianensis cv. CIAT-184, during the organgenesis process under conditions of saline stress

Stylosanthes guianensis cv. CIAT-184 is a promising forage legume for poor and acid soils using for cattle production. In this research were determined the tolerance levels to salinity during in vitro seedling, thus was evaluated the organogenic response and the enzymatic activity of different explants (hypocotyls, cotyledons leaves and leaves) in a callogenic medium supplied with different NaCl levels (0-100 mM). The peroxides and catalases enzymatic activities were determined in both assays, as well as the total carbohydrates and proteins. The highest germination percentage was found between 10-20 mM/L of NaCl; a progressive diminishing of germination percentage was observed as NaCl concentration was increased. During germination assay, was determined an increase in the enzymatic activities of both catalases and peroxidases according the NaCl increasing levels, but in callogenic process the activities diminished after 50 mM of NaCl. It was possible to obtain callus in all treatments used, although the callus showed some differences in texture and colour according to the medium salt concentration.