Submitted to: Canadian Journal of Plant Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/18/2001
Publication Date: 1/1/2002
Citation: CLARKE, J.M., NORVELL, W.A., CLARKE, F.R., BUCKLEY, W.T. CONCENTRATION OF CADMIUM AND OTHER ELEMENTS IN THE GRAIN OF NEAR-ISOGENIC DURUM LINES. CANADIAN JOURNAL OF PLANT SCIENCE. 2002. v. 82. p. 27-33. Interpretive Summary: Durum wheat is a major staple food grain used extensively in pasta production. Many varieties of durum wheat tend to accumulate more of the non-essential and potentially harmful trace metal cadmium in grain than do other wheats. Breeding for lower cadmium levels in grain is facilitated by genetic differences in existing durum wheat cultivars, but little is known about the effect this might have on other important grain characteristics, such as yield, protein content, kernel size, and content of essential mineral elements. Five pairs of otherwise nearly identical wheat varieties containing the gene for high or low cadmium level were compared at five locations in the US or Canada. Grain yield, test weight, kernel weight and protein concentration were determined. Grain was analyzed also for cadmium and other mineral elements. The desired low cadmium trait reduced grain cadmium by more than a half, but did not impair the accumulation of essential and beneficial elements. Nor did the desired trait have any detrimental effect on yield, protein, test weight, or kernel size of grain. This results are very encouraging, and they indicate that standard plant breeding techniques should be capable of developing, without great difficulty or long delay, marketable durum wheat cultivars with low cadmium in grain.
Technical Abstract: Durum wheat (Triticum turgidum L. var durum) shows genetic variation for concentration of the heavy metal cadmium in 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. 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. Concentrations of cadmium, calcium, copper, iron, magnesium, manganese, nickel and zinc were measured in grain from most locations. 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 and among location 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 concentrations of the other elements, but the differences were not associated with the high or low cadmium allele. It was concluded that the low cadmium trait seems to be specific for cadmium and has little or no effect on economic traits or concentrations of other elements.