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.

Cadmium accumulation in crops

“…Large genetic variation in kernel Cd concentration occurred among 200 sunflower lines that were grown at four locations, with the five lowest genotypes being fourfold lower in Cd concentration than the five highest genotypes (Li et al 1993). Genetic variation in Cd uptake has also been reported in carrot (Harrison 1986), potato (Sparrow et al 1992(Sparrow et al , 1993bMcLaughlin et al 1994), flax (Marquard et al 1990) wheat (Oliver et al 1995) and cucumber (Harrison and Staub 1986). Cadmium content varied widely in the cultivars Arcola and Kyle durum wheat and Genesis and Katepwa wheat grown at 12 locations in Saskatchewan (Clarke, Personal Communication, Swift Current, MB, Canada).…”

“…Cadmium accumulation also varies among cultivars within a species (Pettersson 1977;Chang et al 1982;Oliver et al 1995). Chang et al (1982) observed that Cd level varied among barley cultivars, but only when sludge was applied at high levels (Table 1).…”

Concentration of cadmium and other elements in the grain of near-isogenic durum lines

“…Cultivars with genetically determined low levels of cadmium can provide an economical and permanent means of reducing cadmium concentration in these crops to ensure continued acceptability in countries which have statutory limits for cadmium in grain and food products. Such cultivars would give farmers an effective alternative to the restriction of production of certain crops to only those soils with low available cadmium (Oliver et al 1995), or to utilization of uneconomical crop rotations or other management techniques intended to reduce cadmium to acceptable levels (Oliver et al 1993).…”

Cadmium Concentration in Grains of Japanese Wheat Cultivars : Genotypic Difference and Relationship with Agronomic Characteristics

“…Genotypic variation in Cd concentration in grain has been reported in durum and bread wheat (Oliver et al, 1995;Li et al, 1997;Greger and Lofstedt, 2004); however, there are few data on the Cd concentration in grain in Japanese wheat cultivars. Evaluation of Cd concentration in grain in broad genetic resources is necessary to understand the mechanisms of grain Cd accumulation and to construct a breeding program to decrease the Cd concentration in grain in wheat.…”