• 关键词：物种多样性  重金属污染  镉  互补效应

• 基金项目：浙江省自然科学基金(No.LQ14C030001,LY13C030003);浙江省新苗人才计划(No.2014R428010);台州学院2014校立项目

• 杨扬
• 台州学院生命科学学院, 台州 318000

• 王晓燕
• 1. 台州学院生命科学学院, 台州 318000;2. 浙江省植物进化生态学与保护重点实验室, 台州 318000

• 王江
• 1. 台州学院生命科学学院, 台州 318000;2. 浙江省植物进化生态学与保护重点实验室, 台州 318000

• 赵婷婷
• 台州学院生命科学学院, 台州 318000

• 陈思娅
• 台州学院生命科学学院, 台州 318000

• 邵丹丹
• 台州学院生命科学学院, 台州 318000

• 徐佳
• 台州学院生命科学学院, 台州 318000

• 摘要：土壤重金属污染是当今最为突出的环境问题之一,其中,重金属镉(Cd)已成为我国受污染土壤中最主要的无机污染物之一.植物修复法是去除土壤重金属的重要方法,研究表明,植物物种多样性的增加能促进生态系统功能.那么在Cd污染土壤中,植物物种多样性对植物生长和Cd污染修复会有怎样的影响,其内在机理是怎样的并不清楚.基于此,本研究选择6种本地常见草本植物(荆芥、鸡眼草、短叶水蜈蚣、牛筋草、鸭跖草和细风轮菜),通过室内控制实验研究不同植物物种多样性(1-,2-,3-,6-物种)对植物生长与土壤Cd污染修复的影响.结果表明:植物物种多样性的增加显著促进植物地下生物量和总生物量的积累,并对植物根系形态(根总长、根总表面积、根尖总数与根平均直径)和叶绿素荧光参数(PSⅡ最大光能转化效率F_v/F_m和PSⅡ潜在活性F_v/F₀)有显著的促进作用;植物物种多样性的增加能显著提高植物地上、地下及总Cd含量(积累量)和富集系数;植物物种多样性的增加对植物生长、根系形态指标及Cd的富集具有显著的净效应,且以互补效应为主.本研究选取的是对环境条件要求不高、生长周期短的本地草本植物,可为利用本地常见短世代周期植物进行土壤重金属污染修复提供理论依据.

• Abstract：Heavy metal pollution of soil is one of the most prominent environmental problems currently. Cadmium (Cd) has become one of the main inorganic contaminats in polluted soil in China. Phytoremediation is an important method for soil heavy metal removal. Studies also showed that plant diversity could promote the function of ecosystem. However, it was unclear whether the species diversity can affect plant growth and Cd accumulation and the phytoremediation mechanism. In this study, the pot experiments with different species richness (1-,2-,3-,6-species) of six local common herbs (Nepeta cataria, Kummerowia striata, Kyllinga brevifolia, Eleusine indica, Commelina communis and Clinopodium gracile) was conducted to reveal the effects of species diversity on plant growth and soil Cd detoxification. The results showed that plant species diversity could significantly improve underground biomass and total biomass, and promote root morphogenesis (e.g. root length, root surface area, number of root tip and root average diameter) and chlorophyll fluorescence parameters (e.g. PSⅡ maximum light energy conversion efficiency F_v/F_m and PSⅡ potential activity F_v/F₀). Aboveground, underground and total Cd concentrations and enrichment coefficient increased remarkably with the increase of species diversity. Species diversity had significant effect on plant growth, root morphogenesis and Cd concentration, with the complementary effect playing a major role. Moreover, the plant specials selected in our experiments were all local common herbs with relative low environmental requirements and short growth cycle. This study provides a theoretical basis for soil heavy metal removal from local common herbs using short growth cycle.

• Key words：species diversity  heavy metal pollution  cadmium  complementary effect

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