Genotypic differences in effect of cadmium on growth parameters of barley during ontogenesis

A solution culture experiment was carried out in a greenhouse to study genotypic differences in the effect of cadmium (Cd) on biomass, root and shoot growth of barley during ontogenesis, by using four cultivars and four Cd levels. Barley (Hordeum vulgare L) plants exposed to 0.1 muM Cd showed little difference (p > 0.05), compared with control, in growth parameters and biomass accumulation during the first 30 days of Cd exposure, and a slight increase in the later days. Exposure to 1 muM Cd induced a significant decrease and the deleterious effect became diminished with extended exposure of time, which may be attributed to an adaptation to Cd toxicity occurring during ontogenesis. Increasing Cd concentration in the medium to 5 muM caused a sharp decline (p less than or equal to 0.05) in all measurements and the deleterious effect of Cd became more obvious with extended exposure of time. There was a significant difference among 4 cultivars in the reduction of these parameters caused by Cd toxicity. Zhenong 1 and Wumaoliuling were the least and most affected, respectively. In addition, the difference among genotypes in their response to Cd toxicity basically remained consistent throughout the growth period.