SELECTION OF CADMIUM NON-ACCUMULATING RICE GENOTYPES TO REDUCE HEALTH RISK

Abstract

Cadmium (Cd) is regarded as one the most toxic heavy metals. Long term exposure to Cd via air, water, soil or food can be carcinogenic and can also lead to other bone, urinary, reproductive, cardiovascular and nervous disorders. Farmers in order to achieve high quality crops often use excess phosphorus fertilizers and in addition to this leakage of sewage sludge in the agricultural farmlands often leads to Cd contamination in agricultural fields. This holds a long term consequence because the Cd can be easily absorbed by the plants and thus Cd enters the food chain and can get accumulated in human organs. Rice is a major staple crop across the world which holds a vast genotypic variation. Different rice cultivars tends to accumulate different levels of Cd in the rice grains and hence detailed study is required to identify the rice genotypes which do not accumulate Cd in the grains so that they can be regarded as “Cdsafe” cultivars. In the present study, 58 different indica rice cultivars which are popularly grown all over India, have been grown in moderately Cd contaminated soil and results showed differential levels of Cd in the rice grains. Among 58 rice cultivars, 32 cultivars accumulated Cd in the rice grains and rest did not. The rice cultivars namely, Suma, Ranjit, Pratiksha, Kausallya, Ratna, Khitish, Mali-4, Barsha and Annada can be considered to be Cd hyperaccumulators based on the level of Cd accumulation in the rice grains.