Screening of Some Traditional Rice Cultivars of Assam, India, for Their Response to Arsenic-Induced Abiotic Stress

Abstract

Rice is the staple food of more than 700 million people in the world and the most important food crop in Assam, India. However, the metalloid arsenic, which is widespread in the groundwater of many parts of Assam, adversely affects the productivity of different crops, including rice. In this study, seedlings of 23 different traditional rice cultivars were subjected to 0.5 mg/L (low) and 0.8 mg/L (high) arsenic under hydroponic conditions, and various growth parameters (viz., relative water content, shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, and chlorophyll a, chlorophyll b, and total chlorophyll content) were recorded. The cultivars showed varying degrees of susceptibility, as observed by the changes in the different morphological and physiological parameters under arsenic-induced stress. The calculated stress response indices revealed that the cultivar ‘Monasali’ had the best overall tolerance at the high arsenic concentration, whereas ‘Biyoi Sali,’ ‘Baismuthi,’ and ‘Bora’ were most susceptible. On the basis of these observations, ‘Monasali’ was determined as an arsenic-tolerant cultivar, but further biochemical and molecular studies are needed to verify this.