楔叶菊种子及幼苗对镧、铈耐受性及富集特性研究

Tolerance and enrichment of lanthanum and cerium in seeds and seedlings of Chrysanthemum naktongense

以乡土野生花卉楔叶菊(Chrysanthemum naktongense)为研究材料,研究其在不同浓度稀土元素镧(La)、铈(Ce)胁迫下的种子萌发、幼苗生理生化响应及富集特征。结果表明,随着La^(3+)、Ce^(3+)浓度的升高,楔叶菊种子萌发表现出“低促高抑”效应,幼苗地上及地下生物量未发生显著变化,而耐性指数均大于0.5,说明幼苗对于稀土元素的耐受性均较高。La^(3+)胁迫下,楔叶菊幼苗抗氧化系统指标(CAT、SOD、MDA、POD)活性整体呈现显著升高趋势^(3+)Ce^(3+)胁迫下,CAT、MDA、POD整体呈现上升趋势,抗氧化系统指标的升高增强了植物的抗氧化应激水平。楔叶菊根部更容易积累La^(3+)、Ce^(3+)元素,而转移系数均小于0.5,说明由根系向上转移的能力不强。这些结果表明楔叶菊对La^(3+)、Ce^(3+)没有超富集作用,但具有较高的耐受性,根部具有一定的富集作用,可作为La^(3+)、Ce^(3+)污染土壤区域植被恢复的绿化植物使用。

The Chrysanthemum naktongense,a native wild flower,was used as the research material to study its seed germination,seedling physiological and biochemical responses and enrichment characteristics as treated with different concentrations of rare earth elements lanthanum(La)and cerium(Ce).The results showed that low concentration of La^(3+) and Ce^(3+) promoted the germination of C.naktongense seeds,high concentration inhibited the germination.With the increase of La^(3+) and Ce^(3+) concentrations,the aboveground and underground biomass of seedlings did not change significantly,but the tolerance index was greater than 0.5,indicating that the seedlings had high tolerance to rare earth elements.Under La^(3+) stress,the antioxidant system indexes(CAT,SOD,MDA,POD)activities of seedlings showed a significant increase overall.Under Ce^(3+) stress,CAT,MDA,POD showed upward trend.The antioxidant system indexes increased the antioxidant stress level of the plant.The roots of C.naktongense were more likely to accumulate La^(3+) and Ce^(3+) elements,but the transfer coefficient was less than 0.5,indicating that the ability to transfer upward from the root was not strong.These results showed that C.naktongense was not hyperaccumulation plant,but the roots have certain enrichment effect and high tolerance to La^(3+) and Ce^(3+).It could be used as a green plant for vegetation restoration in La^(3+) and Ce^(3+) contaminated soil regions.