ABSTRACT

Soils are one of the repositories for heavy metal. Phytoextraction with hyperaccumulator Tagetes patula (T.patula) has great promise for the cadmium (Cd) removal from contaminated soils. However, there is lack of information about the effects of soil types with different properties on the phytoextraction efficiency and the associated bacterial communities. A pot experiment was performed for 90 d, with four types of soil (black soil, paddy soil, oasis soil, and fluvo-aquic soil) artificially contaminated with Cd at 10 mg kg⁻¹ soil. T.patula showed the greatest Cd uptake efficiency in black soil, followed by paddy soil, oasis soil and fluvo-aquic soil, respectively. Across the four soils, soil pH had the strongest impact on Cd bioaccumulation in T.patula. The Cd uptake amount in T.patula shoot positively correlated with soil CEC, organic matter, total N, total P and total K, and negatively correlated with soil pH and soil particle size. Black soil showed the highest diversity of bacterial community, followed by the paddy, oasis, and fluvo-aquic soils. The structure of communities was altered after phytoremediation albeit to a small degree. Proteobacteria, Acidobacteria, Chloroflexi, Firmicutes, Actinobacteria, Planctomycetes, Gemmatimonadetes, and Bacteroidetes dominated the four soils with different abundances. Soil particle size and CEC had significant negative and positive effects on the richness of the bacterial communities, respectively. These results are important to develop the application of phytoremediation by T. patula in a wide range of Cd-contaminated soils.

摘要

土壤是重金属的储存库之一。使用超富集万寿菊( T.patula ) 进行植物提取对于从受污染的土壤中去除镉 (Cd) 具有很大的前景。然而，缺乏关于具有不同性质的土壤类型对植物提取效率和相关细菌群落的影响的信息。进行了90 d的盆栽试验，对4种土壤（黑土、水稻土、绿洲土和潮土）进行了10 mg kg ^-1 Cd人工污染土壤。斑蝽黑土对 Cd 的吸收效率最高，其次是水稻土、绿洲土和潮土。在四种土壤中，土壤 pH 值对T.patula中 Cd 生物积累的影响最大。T.patula地上部Cd吸收量与土壤CEC、有机质、全N、全P、全K呈正相关，与土壤pH和土壤粒径呈负相关。黑土的细菌群落多样性最高，其次是水稻土、绿洲土和潮土。植物修复后群落结构发生了轻微变化。变形菌门、酸杆菌门、绿曲菌门、厚壁菌门、放线菌门、Planctomycetes、Gemmatimonadetes和Bacteroidetes以丰度不同的四种土壤为主。土壤粒径和 CEC 分别对细菌群落的丰富度有显着的负面和正面影响。这些结果对于开发T. patula的植物修复在广泛的 Cd 污染土壤中的应用非常重要。