腐殖酸对水培小麦吸收硒酸态硒和亚硒酸态硒的影响

目的]研究腐殖酸对水培小麦吸收硒酸态硒和亚硒酸态硒的影响。方法]采用水培试验,研究小麦对10~80μg/L硒酸态硒(Se~(6+))及亚硒酸态硒(Se~(4+))的吸收和腐殖酸的影响。结果]小麦对Se~(4+)和Se~(6+)的吸收与其在培养液中的浓度呈线性关系,小麦对Se~(6+)的吸收是Se~(4+)的6.0~10.5倍。腐殖酸促进小麦对Se~(4+)的吸收,平均增加12.1%;但腐殖酸抑制小麦对Se~(6+)的吸收,平均减少18.6%,且随Se~(6+)浓度的增加抑制作用增强。有腐殖酸存在时小麦吸收Se~(6+)是Se~(4+)的4.3~7.4倍;有腐殖酸时Se~(4+)和Se~(6+)促进小麦生长,Se~(6+)促进作用更为明显,生物量平均增加12.3%。40和80μg/L Se~(4+)培养小麦地上部分吸收的硒分别为初始加入量的3.76%和3.31%,在这2个浓度下,小麦吸收的Se~(6+)分别为初始加入量的27.2%和27.8%。施用Se~(6+)是Se~(4+)作物利用率的7.2~8.4倍。结论]可以通过土壤溶液Se~(4+)或Se~(6+)的浓度调控农作物硒含量,应用Se~(6+)更为经济环保。

Effects of Humic Acid on the Absorption of Selenite and Selenate by Hydroponic Wheat

Objective] To research the effects of humic acid on the absorption of selenite and selenate by hydroponic wheat.Method] The absorption of selenite (Se4 +) and selenate (Se6 +) at 10-80 μg/L by hydroponic wheat was studied under the effect of humic sodium.Re-sult] The absorptivity of selenite and selenate by wheat was positively correlated with the concentration, the wheat absorbed 6.0-10.5 times more of selenate than that of selenite.Humic sodium increased the absorption of selenite by wheat, which was 12.1% on average.But humic sodium inhibited the absorption of selenate by wheat, which was 18.6%on average.The inhibiting ability increased with the concentration in-crease of selenate.Wheat absorbed 4.3-7.4 times more selenate than selenite with the adding of humic sodium.Under such condition, both selenite and selenate promoted the growth of wheat.But selenate had more significant promotion effects with the average biomass increase being 12.3%.At the concentrations of 40 and 80 μg/L selenite, shoots absorbed 3.76%and 3.31%selenite of the initially added amount, respec-tively, and the shoots absorbed 27.2% and 27.8% selenate.The efficiency of selenate applied was 7.2-8.4 times of that slenite.Conclu-sion] The selenium content of cereals could be regulated by adjusting the selenite or selenate concentration in soil solution, and the selenate is the better choice in terms of economic and environmental protection.