四种抗污染木本植物对锑的生理响应及积累特征研究

以臭椿（Ailanthus altissima）、构树（Broussonetia papyrifera）、大叶黄杨（Buxus megistophylla）和紫穗槐（Amorpha fruticosa）4种抗污染木本植物苗木为材料，在盆栽条件下设置0、250、500、1000和2000 mg·kg^-1 5个锑的质量分数梯度，分析胁迫过程中苗木苗高、地径、生物量、耐性指数、相对叶绿素含量、POD活性和SOD活性等指标的变化，探讨这4种苗木对锑胁迫的生理响应，并通过测定苗木地上、地下部分锑的质量分数，明确这几种植物对锑的积累特征，以期为锑污染植物修复材料筛选提供理论基础。结果表明：在不同质量分数锑胁迫下，4种木本植物的苗高、地茎、生物量及耐性指数出现不同程度的下降，其中大叶黄杨在不同质量分数锑处理下的耐性指数均大于90%，表现出对锑较强的抗性。除大叶黄杨外，在中、中高质量分数（500、1000 mg·kg^-1）锑处理后，其他3种木本植物叶片叶绿素含量较对照均显著下降。而在高质量分数锑胁迫下，4种木本植物的叶绿素含量与对照相比均显著下降，表明锑能通过影响植物的光合作用来降低这4种木本植物的生物量合成。在中高质量分数锑胁迫下，4种植物根系的POD和SOD活性均呈现不同程度的增加；在高质量分数锑胁迫下，臭椿、构树和紫穗槐的POD及SOD活性增加幅度减少或受到抑制，表明抗氧化酶系统在植物抵抗锑胁迫过程中发挥重要作用，同时高质量分数的锑胁迫又能降低抗氧化酶系统清除活性氧的能力。在不同质量分数的锑胁迫下，4种木本植物地上、地下部分锑的质量分数存在差异，分别为构树＞紫穗槐＞臭椿＞大叶黄杨，紫穗槐＞构树＞臭椿＞大叶黄杨，表明大叶黄杨可能通过对锑较强的排斥能力，减少锑对叶绿素合成、POD和SOD活性的抑制作用，近而增强了其对锑胁迫的抗性。固氮植物紫穗槐根系最大锑?

Physiological Response and Accumulation Characters of Four Anti-pollution Woody Plants under Antimony Stress

The height, ground diameter, biomass, relative chlorophyll content, tolerance index and the activities of POD and SOD of 4 kinds of antipollution woody plant seedlings of Ailanthus altissima,Broussonetia papyrifera, Buxus megistophylla and Amorpha fruticosa growing on containers with five soil antimony （Sb） mass fraction （0, 250, 500, 1 000 and 2 000 mg·kg^-1） were examined to explore the physiological response of these plants to Sb stress. Mass fraction of Sb in both aboveground and underground part of these plants were also measured to understand the accumulation characteristics of these plants under Sb stress. These researches would provide a theoretical foundation to select plant materials for Sb phytoremediation. The result showed that the height, ground diameter,biomass and tolerance index of all these four species decreased with the increase in Sb mass fraction. Except for Buxus megistophylla, the chlorophyll contents of other three species were significantly reduced under middle and upper-middle mass fraction（500, 1 000 mg·kg^-1）of Sb stress. However, the chlorophyll contents of all these woody plants were reduced under high mass fraction of Sb stress, indicating that Sb could reduce biomass Synthesis by disturb the photosynthesis of these plants. Under upper-middle mass fraction of Sb stress, the activities of POD and SOD in roots of four woody plants were increased while it were reduced or suppressed in Ailanthus altissima,Broussonetia papyrifera and Amorpha fruticosa under high mass fraction, suggesting that antioxidase enzyme system might play a important role under Sb stress and high mass fraction of Sb stress also reduce the capacities of antioxidase enzymes in scavenging reactive oxygen species. These plants showed different capacities of Sb accumulation both in aboveground and underground parts with the order of Broussonetia papyrifera〉Amorpha fruticosa〉Ailanthus altissima 〉 Buxus megistophylla and Amorpha fruticosa 〉 Broussonetia papyrifera 〉 Ailanthus altissima 〉 Buxus