Cadmium accumulation in peanut kernels: effect of location and genotype and its relationship with other factors

Seventy peanut cultivars were planted at two locations to study peanut kernel Cd accumulation. Six entries (8.57%) had a maximum kernel Cd concentration exceeding the European Union allowable upper limit of 0.20 mg/kg. Ten low Cd peanut entries with a maximum kernel Cd concentration below 0.10 mg/kg were tentatively obtained. Location, genotype and their interaction significantly affected peanut kernel Cd accumulation, with location contributing most of the variability (96.67%) and cultivar alone only accounting for 1.69%. Significant positive correlation was detected between kernel protein content and kernel Cd concentration. Negative and positive Spearman rank correlation was also found for SPAD readings and leaf spot ratings with kernel Cd concentration, respectively. The output of this study provides a basis for exploring the mechanisms underlying low Cd accumulation in peanut kernels and for mining relevant genes/QTLs through association analysis.