Cd Uptake And Cd-Zn Correlation In Grains By Hybrid Rice In Two Paddy Soils

Cd pollution of croplands of China has been shown intensified due to the increasing Cd loading from industrial contamination, sewage water irrigation, application of sewage sludge and Cd-containing fertilizers, which poses critical challenge for food security and ecological safety of China. Cd translocation through soil-food crop-diet is generally considered as one of most important pathways for human Cd exposure. Rice is a major source of Chinese food and rice grain has been traditionally consumed as a dormant daily food. Hybrid rice cultivars are extensively cultivated and super rice cultivars with potential yield over 9 t per ha are being extended in rice areas of South China. However, rice has been considered as a particular crop with high Cd uptake and accumulation in grains among the main food crops and Cd-accumulated rice could be resulted from severe Cd pollution araising serious health concerns for Chinese subsistence diet farmers.Knowledge about Cd uptake by hybrid rice and the potential health risks is still insufficient especially the interactive effect of paddy soils and cultivars under field soil conditions although there have been a number of studies on genotype effect on Cd uptake and grain partitioning. In previous studies, it was clearly demonatrated that the uptake of Cd and accumulation in grains could reach a serious level of health risk of non-hybrid cultivars under interaction of genotype and soil types. How such interaction affects Cd uptake and health risk by hybrid rice or super rice is still unknown. In this study, a pot experiment was conducted to elucidate mutual interaction of soil and cultivars on uptake and grain accumulation of Cd by hybrid rice with or without Cd spiking at 2.5mg·kg^-1 under continuous submerging condition. Two hybrid rice cultivars (Shanyou 63, a common hybrid rice and Ⅱ Youming 86, a super-rice) and two paddy soils (a Wushantu, a Gleyic Stagnic Anthrosols and a Hongshanitian, an Ultic Stagnic Anthrosols) were used.The main results were as follows:Significant differences were observed in Cd uptake and grain partitioning between soils, cultivars and the soil-cultivar interactions. The cultivars effect on uptake of...