Water-soluble Carbohydrates in Rice Shoots as Affected by Submergence Stress at Vegetative Stage

Abstract

Submergence stress is one of the most important constraints for the productivity of rice in Bangladesh. A pot experiment was conducted at the net house of the Department of Crop Botany, Bangladesh Agricultural University during Aman season from July 2018 to December 2018 to study the changes in water-soluble carbohydrates in rice plant during the submergence stress and the recovery. The experiment consisted of two factors—(i) rice cultivars (Binadhan-11 and Binadhan-12 as submergence tolerant and BRRI dhan49 as susceptible) and (ii) submergence stress (both control and submerged for 14 days at vegetative stage). Submergence stress was imposed by dipping the pot grown plants into a water tank about 90 cm depth of water for 14 days. After 14 days, plants were removed from the tank and grown in net house. Samplings were done at 0, 5, 10, 14 and 40 days after submergence to measure the contribution of shoot reserves, leaf greenness and shoot dry mass for their survival. Tolerant rice cultivars Binadhan-11 and Binadhan-12 had higher initial soluble carbohydrates than the susceptible one, BRRI dhan49. Under submerged condition the tolerant cultivars showed slow depletion of water-soluble carbohydrate compared to susceptible one. Higher carbohydrate contents in tolerant cultivars might act as buffer stock during submergence for their better survival and growth.