不同体积分数铅尾矿砂胁迫处理对紫茉莉幼苗及耐铅能力的影响

Influences of Stress Treatment of Pb Tailings Sand on the Seedling of Mirabilis jalapa L. and Pb Tolerance Ability in Different Volume Fraction

以紫茉莉(Mirabilis jalapa L.)幼苗为试材,采用土培试验方法,研究了紫茉莉幼苗在体积分数为0%(CK)、25%、50%、75%、100%的Pb尾矿砂基质中对其生长以及生理指标的影响。结果表明:幼苗的株高、根长以及耐性指数随Pb尾矿矿砂体积分数的增加呈逐渐降低的趋势且均低于CK;随Pb尾矿砂体积分数的增加,幼苗叶片中Chla、Chlb和Car的含量变化与其生长指标变化一致且在纯Pb胁迫下,光合色素的含量较CK差异显著(P<0.05),分别降低了92.1%、89.8%和82.6%;在纯Pb尾矿砂胁迫处理下,幼苗地上、地下部相对电导率均高于CK且差异显著(P<0.05),较CK增加了26.01%、10.55%;在Pb尾矿砂处理条件下,幼苗地上部GSH含量呈Pb低体积条件增加、Pb高体积条件降低的趋向,在50%Pb处理下各培养组幼苗地上部的MDA和AsA含量最明显,而地下部MDA、AsA和GSH含量变化无明显规律性;综上所述,紫茉莉对低体积分数的Pb尾矿矿砂环境有一定的耐性,可为轻度Pb污染环境的修复方面提供一定的参考依据。

The seedling of Mirabilis jalapaL.was taken as experimental material,and the soil culture experiment was carried out to analyze its growth and physiological index in Pb tailings sand substrate with different concentration at 0%,25%,50%,75% and 100%.The results showed that the plant height,root length and tolerance index of seedlings tended to decrease with the increase of the volume fraction of Pb tailings sand,and they were lower than those of the control.Meanwhile,with the increase of the volume fraction of Pb tailings sand,the content changes of Chl a,Chl b and Car in the seedling leaves were consistent with those of the growth index.However,the content of photosynthetic pigments was significantly different from those of the control under the stress of pure Pb（P〈0.05）.It was decreased by 92.1%,89.8% and 82.6% respectively.Under the stress treatment of pure Pb tailings sand,the relative conductivity of above-ground and under-ground parts of seedlings were significantly higher than those of the control （P〈0.05）.It was increased by 26.01% and 10.55% respectively.Under the stress treatment of Pb tailings sand,the content of GSH in the overground part of seedlings was increased with low volume Pb and decreased with high volume Pb.Under the stress treatment of 50% Pb,the content changes of MDA and ASA in above-ground part of the seedlings was significant,while the content of MDA,ASA and GSH did not change regularly.To sum up,Mirabilis jalapa L.had a certain tolerance to the low volume fraction of Pb tailings sand,which provides a theoretical basis for the research of the restoration of mild Pb pollution.