Differential responses of Australian wheat cultivars to cadmium concentration in wheat grain

Abstract

Cadmium concentration in grain was studied for wheat cultivars grown nationally in the Interstate Wheat Variety (IWV) experiments (1988 and 1989) and cultivars grown in the Western Australian (WA) experiments (1990-1992). These experiments covered a range of differing soil and environmental conditions. The adaptation of these cultivars to changes in cadmium potential at a site was determined. Significant cultivar effects were identified, but these were less significant than the site effects. The Cd concentrations in grain exceeded the current Australian maximum permitted concentration (MPC) of 0.05 mg kg-1 at one site in the IWV experiments while the concentration exceeded the MPC at a larger proportion of sites in the WA experiments. Several trends in cultivar accumulation of Cd in grain were evident. Reeves and Kulin were found to have the highest Cd concentration at a number of sites for several years in both the IWV and WA experiments. The similar pedigrees of these two cultivars suggest that while wheat breeders were selecting for certain traits during the breeding selection process, they were inadvertently selecting for the ability to accumulate Cd. In the 1992 WA cultivar experiments, generally Aroona had the highest Cd concentration in grain. Aroona has different pedigree to Reeves and Kulin. Several of the cultivars that were low Cd accumulators also had similar pedigrees. This indicates that there is potential for selecting lines that are low Cd accumulators to be grown in areas where Cd accumulation in grain is a problem.