镉及镉与铁、锌互作对水稻生长的影响

摘要

为了研究铁、锌与镉在吸收运转上的互作效应及其对苗期水稻生长的影响,采用木村B溶液培养试验,以水稻品种威优46和 C 两优266为材料,应用随机区组设计,添加0.0,0.1,0.5,1.0,2.0 mg/kg Cd2+处理,以及 CK (1.0 mg/kg Cd2+)、TFe(CK+ 5.0 mg/kg Fe2+)和TZn(CK+ 5.0 mg/kg Zn2+)处理.结果表明,随着镉浓度的增加,2个水稻品种地上部干质量和根部镉转运系数呈下降趋势,而地上部和根部镉含量、总镉含量和根部镉净吸收量呈上升趋势,且威优46的地上部干质量和镉含量均高于C两优266.外源添加Fe2+显著提高了C两优266的地上部干质量,显著降低了威优46根部镉含量,但对2个水稻品种其他部位的镉含量以及镉转运的影响不大,表明Fe2+处理后可以抑制威优46根部对镉的吸收.Zn2+处理增加了2个品种水稻的根部和地上部分干质量以及地上部镉含量,但是降低了威优46根部镉含量,这表明Zn2+处理后促进了Cd2+从根部到地上部的转运,且通过抑制水稻根部发育从而降低水稻对Cd2+的吸收.由此可见,外源添加Fe2+、Zn2+可以缓解镉对水稻生长发育的毒害作用,且缓解程度存在明显的品种差异.%This work was designed to study the interaction effects of cadmium with iron,zinc on the growth of rice seedling and the cadmium absorption and translocation in the rice seedling. This study included two experi-ments,which both used the rice variety of Weiyou 46 and C-liangyou 266 under the hydroponic culture conditions. Experiment Ⅰ was designed to explore the cadmium concentration on the cadmium transportation in the rice seed-ling and included the treatments of 0.0,0.1,0.5,1.0,2.0 mg/kg Cd2+. ExperimentⅡwas designed to explore the interaction of cadmium with iron,zinc on the growth of rice seedling and included the treatments of CK (1.0 mg/kg Cd2+), TFe (CK +5.0 mg/kg Fe2+) and TZn (CK +5.0 mg/kg Zn2+). Results of Experiment Ⅰshowed that the above-ground biomass weight and cadmium transport coefficient decreased in the roots of two varie-ties with the increasing of Cd2+concentration,while the cadmium content and cadmium accumulation in the above-ground and roots,the roots cadmium uptake increased. There was a general trend that the above-ground biomass weight and cadmium content of Weiyou 46 were higher than that of C-liangyou266. Results of Experiment Ⅱshowed that applying Fe2+significantly increased the above-ground biomass weight of C-liangyou 266 and decreased the root Cd content of Weiyou 46,but with insignificantly effect on the cadmium transport and Cd content in other parts of both rice varieties. This indicated that Fe2+application would restrain the cadmium absorption in roots of Weiyou 46. Zn2+treatment increased the above-ground biomass weight and Cd content in both rice varieties,while reducing the Cd content in root of Weiyou 46. This indicated that Zn2+application would promote the transportation of Cd2+from root to top, and inhibit Cd2+uptake through inhibiting the development of rice roots. Therefore, adding Fe2+and Zn2+to soil can alleviate the toxic effects of cadmium on the rice growth.