EVALUATION OF INDUCED WATER STRESS RESPONSES IN COMMERCIAL RICE (ORYZA SATIVA L.) GENOTYPES IN THE DOMINICAN REPUBLIC

Abstract

Due to the negative effects of climatic change on agricultural production, it is becoming more necessary to determine crops with tolerance to adverse environmental conditions such as drought. In order to determine rice (Oryza sativa L.) genotypes with potential tolerance to water stress, the physiological and biochemical responses of commercial varieties grown in the Dominican Republic to induced water stress were analyzed; this by utilizing polyethylene glycol 8000 (PEG-8000) as stress inductor. Said substance tend to cause osmotic stress thanks to its viscosity under certain temperatures, restricting the transport of water through the plant membranes leading to water deficit. According to preliminary results, the varieties Jaragua and Quisqueya performed relevant physiological responses by having larger seedlings and roots which indicates adaptations for water browsing. On the other hand, the variety Aceituno had surprising biochemical responses with the highest accumulation of chlorophyll b which is attributable to the light conditions that seedlings were submitted, also, as a defense to water stress by carrying the function of replacement molecule for energy transport in the Photosystem II during photosynthesis, because of the dehydration of chlorophyll a. These results suggest the existence of a tolerance index among rice varieties grown in the Dominican Republic.