Genotypic Differences Among the Rice Genotypes to Arsenic Stress Cultivated Under Two Water Regimes: With an Inference to Human Health

Arsenic (As), a carcinogenic metalloid, is a serious threat to humans due to increased exposure through contaminated water and food. Rice is a staple food and feeds over half of the World's population. Among cereals, rice is more efficient in As uptake and its acquisition into rice grains adversely affect the quality of rice as well as the consumer’s health. The exploitation of genetic variation between rice genotypes for their ability to tolerate water limitations and As accumulation in grains is crucial. The study aimed to investigate the genetic potential of seven rice genotypes for their ability to withstand water limitation (aerobic cultivation) and As toxicity (As-100 µM). The results revealed that under aerobic cultivation system rice genotypes showed less As accumulation in the grains as compared to anaerobic cultivation. Moreover, among all the rice genotypes, less As accumulation in grains was observed in DHAN 140A (2.36 and 3.65 µg g−1) and Shaheen Basmati (2.92 and 3.55 µg g−1), respectively, under aerobic and anaerobic cultivation at high As soil contamination (As-100). Rice genotypes differentially responded against As stress and the cultivation conditions in terms of growth attributes and elemental composition of the plants. Moreover, health risk indices (i.e. ILTCR and HQ) indicate high carcinogenic and non-carcinogenic risks associated with rice consumption grown under high As stress. However, the risks were several folds higher in anaerobically than aerobically cultivated rice genotypes. Among all the genotypes, DHAN 140A indicated less risk, irrespective to the cultivation condition due to decreased As uptake and accumulation of in the grains. The study demonstrated that aerobic water management and selection of genotypes with low As accumulation could be appropriate options to minimize the health risk to human beings.