关键词: 玉米, 铅, 镉, 富集, 转运

Abstract: Based on a pot experiment using 10 cultivars of maize from 10 difference production areas, characteristics of the maize adsorbing and accumulating heavy metals, like Pb and Cd were studied. Results show that under combined Pb (400.0 mg · kg^-1）and Cd (10.0 mg ·kg^-1) stress, the accumulation of Pb in maize varied with the growth stage, displaying decreasing order of ripening stage＞jointing stage＞seedling stage, while the Cd accumulation in maize did, too, but displaying a different order, i.e. seedling stage ＞ jointing stage ＞ milking stage. In addittion, the distribution of Pb and Cd in the plant also varied, showing an order as root ＞ stem ＞ leaf ＞ grain, which means that root was the main part where the heavy metals were accumulate. Obviously, the 10 cultivars of maize all exceeded the criteria for Pb (≤0.2mg· kg^-1) in grains specified in the National Sanitation Standard of China (NSSC),in content of Pb, while Cultivars Guangtian 3, Guoshenjun 79-5, Xinghuangdan 892, Jindan 51, and Beike were under the criteria for Cd (≤0.1mg· kg^-1) in grain specified in the NSSC. The lowest accumulation of Cd was found in Guangtian 3, which suggested that this maize cultivar can be extraploted to areas slight or medium in soil pollution.

Key words: maize, lead, cadmium, accumulation, transfer