施硒对花生镉吸收与抗性及化学形态的影响

采用温室盆栽试验,研究了低镉(Cadmium,Cd)浓度与高Cd浓度条件下,施硒(Selenium,Se)对花生生长、抗逆生理、Cd吸收积累及Cd在花生植株中形态的影响。结果表明,不同Cd条件下施Se均显著影响花生生物量。施Se可以缓解细胞膜的损害,降低丙二醛的积累。Cd胁迫抑制了花生的光合作用,随Se浓度增大,花生叶片光合速率呈现先升高后降低的趋势。Cd污染条件下,随施Se浓度增大,花生叶片及根系Cd含量先降低后升高,且在Se浓度为0.25 mg·kg~(-1)时效果最显著。在低Cd处理(3 mg·kg~(-1))和高Cd处理(30 mg·kg~(-1))条件下,施加0.25 mg·kg~(-1)Se使花生地上部分及根系Cd含量分别下降了12.71%、46.13%和21.29%、36.00%。花生植株中Cd形态以氯化钠提取态(FNaCl)、醋酸提取态(FHAc)和水提取态(FW)为主要形态。施Se处理可提高花生根部FHAc和FW提取态Cd的分配比例。研究结果显示,适量施Se可有效降低花生植株体内活性态Cd的比例,减少Cd的吸收。

The effect of selenium on cadmium accumulation,chemical forms and the resistance of peanuts

This paper investigates the influence of selenium on growth,physiological resistance,accumulation and chemical forms of cadmium(Cd) in peanuts under varied treatments of Cd(0,3,30 mg·kg^-1) through a series of experiments. Results showed that,application of Se influences peanut biomass significantly for all different Cd levels,and Se amendment decreased the accumulation of MDA and cell membrane damage. Cd stress significantly reduced the net photosynthesis rate of peanuts,and the net rate of photosynthesis first increased and then decreased with increasing Se levels. Under Cd pollution(3,30 mg·kg^-1),Cd concentrations in the peanut plants first decreased,then increased with increasing Se levels. The lowest Cd concentration in peanuts occured when treated with 0.25 mg·kg^-1 Se application. When soil Cd concentrations were 3 mg·kg^-1 and 30 mg·kg^-1,Cd concentrations in the shoots and roots decreased by 12.71%,46.13% and 21.29%,36.00%,respectively,under 0.25 mg·kg^-1 Se treatment. NaCl,HAc,and water-extractable Cd were predominant in peanuts. Application of Se increased HAc and water-extractable Cd. Results showed that moderate Se application could effectively inhibit Cd activity and decrease Cd transportation and accumulation in peanut plants.