ANÁLOGOS DE BRASINOESTEROIDES REVIERTEN PARCIALMENTE EL IMPACTO DEL ESTRÉS SALINO EN EL CRECIMIENTO INICIAL DE LAS PLÁNTULAS DE DOS GENOTIPOS DE ARROZ (Oryza sativa L.).

The effect of two formulations based on spirostane brassinosteroid analogs known as BIOBRAS-6 (BB6) and BIOBRAS-16 (B16) on seedling growth of two rice varieties under saline conditions was studied in the present paper. Seeds of J-104 and INCA LP-7 varieties were dipped in water, 100 mM NaCl or 100 mM NaCl supplemented with different concentrations (1, 0.5, 0.05 and 0.005 mg.L-1) of B16 or BB6 for 24 hours. Later, seeds were placed in Petri dishes with filter paper dampened with distilled water for germination and maintained in a growth chamber at darkness during 48 hours. Germinated seeds were transferred to pots containing the different assayed solutions and placed in a growth chamber with 16 hour- photoperiod and 25±2°C temperature for seven days. At the end of the experiment, shoot and root lengths as well as fresh and dry weights were evaluated. Results showed that, in general, 0.005 mg.L-1 of B16 was the most effective treatment to revert adverse effects induced by salinity in both varieties, whereas the response to BB6 depended on the variety. [ABSTRACT FROM AUTHOR]