硒对小白菜生长和养分吸收的影响

以小白菜为材料 ,研究了硒对植株生长和养分吸收的影响。结果表明 ,当营养液中加入低浓度硒 (Se 1.0mg L)时促进了小白菜的生长 ,增加了产量 ;加高浓度硒 (Se 2 .5mg L)时则抑制了小白菜的生长。加硒后增加了小白菜地上部可溶性总糖、还原糖含量 ;降低了蔗糖和淀粉的含量 ;低浓度硒增加了粗纤维含量 ,而高浓度硒则降低了其含量 ;Se 1.0mg L的硒处理降低了植株地上部总蛋白质的含量 ,但随着硒浓度的进一步增加 (Se 1.0mg L)植株体内的总蛋白质含量逐渐升高 ,并大于对照。加硒后增加了小白菜地上部游离氨基酸总量和N、Ca、Mg、Mn、Zn含量 ,降低了P、K、S元素的含量 ;与对照相比 ,加硒后增加了小白菜地下部N、S元素的含量 ,降低了P、Ca、Mg、Fe、Mn、Zn元素的含量 ,但对K元素的影响不大。无论是小白菜地上部还是地下部 ,体内硒的含量均与营养液中硒的浓度呈显著的正相关。植物地上部硒的含量以有机态硒为主 ,有机硒转化率均在 80 %以上。

Effects of selenium on the growth and nutrient absorption of pakchoi

Effects of selenium on the growth and nutrient absorption in pakchoi(Brassica campestris ssp. chinensis L.)were studied. The results showed that the plant growth was promoted at lower selenite concentration, while it was inhibited at higher selenite concentration. The contents of soluble sugar and reducing sugar in shoots of pakchoi were increased, while those of the sucrose and starch were decreased. The content of cellulose was increased at lower selenite concentrations, but decreased at higher selenite concentrations. The content of protein was decreased at the treatment (Se≤1.0 mg/L ), but it was increased gradually with the increase of selenite concentration in the solution. The content of total free amino acids was higher than control. The contents of N, Ca, Mg, Mn, Zn in shoots of pakchoi treated with selenite were increased, while those of P, K, S were decreased. Compared to the control, the contents of N, S in roots of plant were increased while those of P、Ca、Mg、Fe、Mn、Zn were decreased at the treatment, but the K content was hardly affected . The content of selenium in either shoots or roots of the plant was positively correlated with the selenite concentration in the solution. Most of the selenium form in plant was organic selenium and the organic selenium invert rates were above 80 percent in all treatments.