Physiochemical Responses and Cold Survival Mechanism of Rice Seedlings of Selected Cultivars in Northwest Bangladesh

摘要

Cold stress at seedling stage is a serious concern to the sustainable rice production in some regions of the world. A field experiment was carried out to investigate the physiological parameters of seedlings of selected five rice cultivars, namely Binadhan-6, BR-26, BRRI dhan28, BRRI dhan29, and BRRI dhan50 (Banglamoti) for cold survival mechanism during low temperature in the Northwest Bangladesh. The field experiment was arranged following Randomized Complete Block Design (RCBD) with three replications. The physiological parameters such as leaf proline, chlorophyll, total carotenoid content, relative water content (RWC) and starch were determined. In this study, the rice cultivars showed significant variation of physiological activities at low temperature. BRRI dhan28 synthesized the highest amount of proline (1.25 mg g~(-1)), chlorophyll-a (2.63 mg g~(-1)), chlorophyll-b (0.85 mg g~(-1)), relative water content (93.33%) and starch (28.21%) content. Significant variability was observed among the cultivars during the experiment time for their survivability. The sequence of survival potentiality was observed as BRRI dhan28 BRRI dhan29 BR-26 BINA dhan-6 BRRI dhan50. The present finding infers that BRRI dhan28 showed the best survival potentiality based on the synthesis of proline, chlorophyll and other physiological parameters.