不同水稻品种积累镉的差异及其动态变化

Difference and dynamics of Cd uptake in four rice cultivars

采用盆栽试验,研究了广西4个水稻(Oryza sativa)品种在红壤和水稻土上积累镉的差异及其动态变化。结果表明,红壤与水稻土相比,更利于镉向水稻体内转移;水稻对镉的积累有明显的基因型特征,籽粒中镉含量随镉浓度加大而显著提高,在外加镉浓度为2.0 mg/kg条件下,红壤土栽培的水稻籽粒镉含量超过了0.2 mg/kg食品卫生标准;不同水稻品种对镉的积累存在显著差异,4个品种吸镉量随取样时期呈现先升高后降低的趋势,特优1012和培杂泰丰镉积累量高于其他两个品种。因此,在污染土壤上宜选种食用部位重金属积累低的水稻品种,以减少人类吸收重金属的风险。

Pot experiment was conducted to study the differences and dynamics of Cd accumulation among four different rice varieties cultured on the red soil and paddy soil in Guangxi. The result indicated that Cd accumulation in grains of the four rice varieties was significantly different. Compared with the paddy soil, the rice varieties grown the red soil accumulated more Cd in grains. The rice varieties exhibited the genetic character on the Cd accumulation. The Cd contents of the grains increased with the increasing Cd concentration in soil. Under the 2.0 mg/kg treatment, the grain Cd went beyond the limit of the food health standards （0.2 mg/kg） in the red soil. During the treating period, the Cd accumulation of the four rice varieties increased up to a peak, and then decreased. Cd accumulation of Teyou1012 and Peizataifeng were higher than that of the others. Therefore, for reducing the risk of the humanity to heavy metal, the rice varieties with the low capability of accumulating heavy metal in grains could be planted in a polluted soil.