Efecto del estrés salino en el crecimiento y contenido relativo del agua en las variedades IR-43 y amazonas de Oryza sativa "arroz" (Poaceae).

Oryza sativa L. "rice" (Paceae) is one the most important crops worldwide. However, it is drastically affected by salinity. Therefore, the objective of this research was to determine the effect of salinity over the absolute growth rate (AGR) and the relative water content (RWC) of rice varieties IR-43 and amazonas. "Rice" seedlings were grown in hydroponic conditions with nutritive solution La Molina® and arranged in a factorial design. 16-day plantlets were treated with NaCl solutions 0, 100, 150 and 200 mM to determine AGR and RWC at 8-day-treatment. Salinity stress affected both variables. IR-43 was more affected when treated with 200mM NaCl, showing AGR of 12.46 and 19.04 mm/day in shoots and roots respectively; when treared with 100 mM, RWC was 73.35%. The Amazonas variety had more tolerance to salinity, with AGRs of 21.25 and 22.54 mm/day in shoots and roots treated with 200mM NaCl, respectively; and RWC was 78.47% at 100mM. The reduction in growth could be caused by changes in cell water state caused by salinity and changes in nutrient and water uptake. The differences in stress response to salinity in both rice varieties showed advantages in osmotic adjustment and regulation to maintain cell homeostasis of Amazonas over IR-43 rice varieties. [ABSTRACT FROM AUTHOR]