Cadmium accumulation characteristics of low-cadmium rice (Oryza sativa L.) line and F1 hybrids grown in cadmium-contaminated soils

Abstract

Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg soil, respectively. Cd concentrations in ear of F hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F hybrids were less than 0.2 mg kg at 1 mg Cd kg soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg soil).

Genome-wide association study and candidate gene analysis of rice cadmium accumulation in grain in a diverse rice collection

“…It has been reported that approximately 20 million hectares of cultivated lands in China, or 20% of the total, were contaminated by Cd (Hu et al 2016 ). Cd can be readily absorbed by the roots of crops and transferred to aboveground organs, then enter the human body through the food chain (Li et al 2017 ). Rice is a staple food for nearly half of the world’s population, and compared to other cereal crops, rice tends to accumulate more Cd (Hu et al 2016 ).…”

Breeding for low cadmium accumulation cereals

“…In rice, Arao and Ae (2003) investigated genotypic variation in grain Cd content, and identified three cultivars with the lowest Cd concentrations. Since then, many researchers have investigated the genotypic and environmental variation in Cd accumulation and distribution in rice and attempted to select low-Cd genotypes (Liu et al, 2005(Liu et al, , 2007He et al, 2006;Yu et al, 2006;Yan et al, 2010;Cao et al, 2014b;Pinson et al, 2015;Li et al, 2017;Zhou et al, 2017). In general, durum wheat tends to accumulate more Cd in grains than bread wheat (Stolt et al, 2003;Greger and Löfstedt, 2004).…”

Effects and Mechanism of Continuous Liming on Cadmium Immobilization and Uptake by Rice Grown on Acid Paddy Soils

“…Rice (Oryza sativa L.) is one of the most globally important food crops, especially in Asia and the Pacific region (Li et al 2017). The continuously growing world population and the adverse impacts of climate changes necessitate carrying out research aimed at ensuring the sustainable production of such a staple crop and food security through agro-ecological managerial practices (El-Mahdy et al 2018;Eissa and Negim 2018;Abou-Elwafa et al 2019).…”