硒对汞胁迫小麦幼苗生理特性的影响

通过沙基培养研究不同ρ（Se）对Hg胁迫下小麦（Triticum aestivum L.）幼苗苗高、叶绿素相对含量（SPDA）、丙二醛（MDA）含量及抗氧化酶活性等的变化,探讨外加Se对Hg胁迫下小麦幼苗生理活性的影响。结果表明：单独ρ（Hg）=2.5 mg.L-1处理下,小麦幼苗叶绿素含量降低,SOD与CAT活性受到抑制降低,丙二醛（MDA）含量升高。ρ（Se）=5 mg.L-1和ρ（Hg）=2.5 mg.L-1共同处理下,叶绿素含量比Hg单独处理升高了7.6%,比对照升高了3.5%,MDA含量降低了38.8%,低于对照20.0%;外加ρ（Se）高于10 mg.L-1的处理中,叶绿素含量逐渐降低,MDA则呈升高趋势。ρ（Hg）=2.5 mg.L-1胁迫下低ρ（Se）=5~10 mg.L-1促进了SOD与CAT活性,其活性随Se质量浓度升高逐渐增强;ρ（Se）=10 mg.L-1和ρ（Hg）=2.5 mg.L-1共同处理下,两种酶活性比Hg单独处理分别升高了21.8%与32.8%,高ρ（Se）=15~20 mg.L-1处理下,两种酶活性则呈下降趋势。这些结果表明,不同ρ（Se）对Hg胁迫下小麦幼苗各生理指标具有显著影响,Se一定程度上缓解了Hg对小麦幼苗的毒害。

Effects of Se on some physiological characteristics of wheat seeding under Hg stress

Our objective was to study the effects of additional Se on the physiological activity of wheat seedlings under the stress of Hg. Wheat seedlings were treated with different concentration ofp（Se）=5-20 mg.L＂1, then the height of seedling, the relative content of chlorophyll, the accumulation of MDA and antioxidant enzyme activities of Trimicum aestivum L.wheat seedlings under Hg stress （2.5 mg.L1） were tested by field commander culture method. We found that treatment with p（Hg）=2.5 mg.Lq alone led to decreasing of concentration of chlorophyll, inhibition of the activity of SOD and CAT, and increased content of MDA in sweat seedlings. In further research, we co-treated the wheat seedlings with Se and Hg at the the concentration of mg＇Ll and Hg mg.Lq respectively. With cotreatment, chlorophyll content increased by 7.6% than the Hg treatment alone, and 3.5% higher than the control; MDA levels decreased by 38.8%, 20.0% lower than the control. When treated with additional Se at high concentration more than 10 mg＇L1, the chlorophyll content of wheat seedlings decreased gradually, while MDA content showed an rising trend. Treatment with additional Se at a concentration of 5-10 mg.Lq led to promotion of the activity of SOD and CAT, and their activities increased with the rise of Se concentration. Co-treated with Hg and Se at the concentration ofp（Se）=10 mg.Lq and p（Hg）=2.5 mg＇Lq respectively increased the activity of the two kinds of enzymes above by 21.8% and 32.8%, comparing with the single treatment with Hg. However when p（Se） increased at 15 mg-Ll to 20 mg.L1, the downtrend of their activities appear. These results elucidated that treatment with different concentration of Se and Hg appreciable impact on the physiology index, and Se can alleviate the toxicity of Hg to wheat seedlings.