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. |
