楝树等不同树种对Cd污染土壤的修复作用  

Rehabilitation of Cadmium-contaminated Soil by Different Tree Species Such as Melia azedarach

作　　者：赵竑绯 曹志华 陈丹维[1] 王娟[1] 饶显龙 李珏[1] 钟泰林 Zhao Hongfei;Cao Zhihua;Chen Danwei;Wang Juan;Rao Xianlong;Li Jue;Zhong Tailin(College of Urban Construction,Zhejiang Shuren University,Hangzhou,310015;Institute of Timber and Bamboo,Anhui Academy of Forestry Sciences,Hefei,230036)

机构地区：[1]浙江树人大学城建学院,杭州310015 [2]安徽省林业科学院用材林及竹子研究所,合肥230036

出　　处：《分子植物育种》2022年第2期570-576,共7页Molecular Plant Breeding

基　　金：浙江树人大学青年学术团队项目;高级别预研项目(KBY0119604C,KXJ0218105);“十三五”国家重点研发计划项目(2018YFD06001);中央引导地方科技发展专项(201907A03050001)共同资助。

摘　　要：利用树木对重金属污染地进行植物修复可能优于作物,因为木本植物生物量大、富集高、修复时间更久。本研究评估了3个多用途树种对镉(Cd)的植物修复潜力:桉树(Eucalyptus robusta)、银合欢(Leucaena leucocephala)、楝树(Melia azedarach)。对3个树种施加0、10、20、40、80和120 mg Cd/kg这6个浓度的Cd溶液(CdCl_(2)·H_(2)O)。经过18个月的生长后,采收样品,并测定了叶、茎、根干物质(dry matter, DM)及各部位Cd的含量,同时测定种植前和收割后土壤中的Cd含量。结果显示,在所有浓度处理下,银合欢的总干物质含量均为最高,而桉树最低。与对照相比,施用最高水平Cd (120 mg/kg土壤)时,桉树、银合欢和楝树的干物质产量分别下降了48%、40%和25%。在各个部位中,叶子中Cd的含量最高,而茎吸收Cd的能力最强。在各个Cd浓度处理下,银合欢富集Cd的能力最强,而Cd污染对楝树影响的安全临界值(85 mg/kg)最高。因此,苦楝对Cd的耐受性最强而银合欢对修复Cd污染土壤的潜力最大。Phytoremediation of heavy metal-contaminated sites using trees may be preferred over crops due to its plants have large biomass, high enrichment and longer remediation time. A study was undertaken to assess the cadmium(Cd) phytoextraction potential of three multipurpose tree species which are Eucalyptus( Eucalyptus tereticornis), Subabul(Leucaena leucocephala) and Dhrek(Melia azedarach) at six rates of Cd applied in solution form through CdCl_(2)·H_(2)O(0, 10, 20, 40, 80 and 120 mg Cd/kg soil) and harvested after 18 months of growth in an alkaline loamy sand soil in plastic drums. Dry matter(DM) of leaves, stems and roots, Cd content of these constituents and that of soil before planting and after harvesting the tree species were determined. Subabul had the highest and eucalyptus the lowest total DM production at all levels of Cd. As a result, Subabul had the highest and eucalyptus the lowest total DM production at all levels of Cd. The highest Cd level resulted in 48%, 40% and 25% reduction in total DM of eucalyptus, subabul and dhrek, respectively over control. Cadmium concentration was higher in leaves whereas uptake was higher in stems than the other components. The upper critical level of available Cd in the soil was the highest for dhrek(85 mg/kg) and the lowest for eucalyptus. Therefore, dhrek was more tolerant to Cd but subabul had the greatest potential for phytoextraction of Cd from the soil.

关 键 词：CD污染 植物修复 桉(Eucalyptus robusta) 银合欢(Melia azedarach) 楝树(Leucaena leucocephala) 

分 类 号：X53[环境科学与工程—环境工程] X173