Water management regimes alter Pb uptake and translocation in fragrant rice.

ABSTRACT

Rice cultivation in lead (Pb) polluted soils often leads to high Pb contents in rice grains. The present study investigated the dynamics of Pb uptake under different water regimes in two fragrant rice cultivars i.e., Guixiangzhan and Nongxiang-18. Results revealed that water dynamics regulated the antioxidant activities in both rice cultivars under Pb toxicity. Compared to continuous ponding (CP), taken as control, alternate wetting and drying (AWD) reduced the Pb contents in roots, stems, leaves, and grains up to 17%, 41%, 22%, and 52% in Guixiangzhan and 23%, 19%, 17%, and 37% in Nongxiang-18, respectively. Furthermore, AWD-treatments reduced paddy yield from 11% to 21% in Guixiangzhan and 11-33% in Nongxiang-18 under Pb toxicity. In conclusion, Pb loadings in fragrant rice can be regulated by effective water management and/or by controlling irrigation water at different growth stages. Special control measures or management is required to cultivate the rice in metal(loid)s polluted soils.