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

Abstract

Durum wheat (Triticum turgidum L. var durum) shows genetic variation for concentration of the heavy metal cadmium in the grain. This variation is being exploited to develop cultivars with low cadmium concentration, but there is no information on the effect of incorporation of the trait on uptake of other elements or on economic traits such as yield. Five pairs of near-isogenic high/low cadmium durum wheat lines and their parents were grown in a randomized complete block trial with three replications. Trials were grown at Swift Current, Saskatchewan in 1994, at Swift Current, Stewart Valley and Regina, Saskatchewan in 1995 and 1996, at Langdon and Fargo, North Dakota in 1995, and at Casselton and Langdon, North Dakota in 1996. Grain yield, test weight, kernel weight and protein concentration were determined. Grain cadmium, calcium, copper, iron, magnesium, manganese, nickel and zinc were measured by atomic absorption or inductively coupled plasma emission spectroscopy. The low cadmium trait had no significant effect on average yield, grain protein concentration, test weight, or kernel weight as indicated by comparison of the high and low cadmium isolines. Average grain cadmium concentration differed among years within locations, among locations within years, and among genotypes. The average grain cadmium concentration of the high cadmium isolines was approximately double that of the low cadmium isolines. There were significant genotypic differences in grain concentration of the other elements, but the differences were not associated with the high and low cadmium isogenic lines. The low cadmium allele seems to be specific for cadmium, lowering cadmium without altering concentrations of other elements or affecting economic traits. Key words: Triticum turgidum L. var durum; grain cadmium concentration; grain yield