Pb^(2+)胁迫下黑麦草对外源有机酸的响应机制  

Response Mechanism of Exogenous Organic Acid on Ryegrass Under the Stress of Pb^(2+)

作　　者：乔冬梅[1,2] 樊向阳[1,2] 樊涛[1,3] 胡超[1,2] 赵志娟[1,3] 胡艳玲[1,2] 高青[1,2] 

机构地区：[1]中国农业科学院农田灌溉研究所,河南新乡453003 [2]中国农业科学院河南新乡农业水土环境野外科学观测试验站,河南新乡453003 [3]中国农业科学院农业水资源高效安全利用重点开放实验室,河南新乡453003

出　　处：《水土保持学报》2012年第2期261-264,270,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(50809074);国家科技重大专项(2008ZX07425-004)

摘　　要：为探讨根系分泌有机酸对植株吸收富集Pb2+的影响,土壤Pb2+含量为500mg/kg的条件下,设计外源有机酸类型为草酸、冰乙酸、丙二酸、酒石酸和苹果酸,其浓度均为1,3,5,6,7mmol/kg。在模拟日光温室中采用盆栽根袋法对黑麦草生长发育指标,根际与非根际土壤理化性质及黑麦草吸收富集效果进行分析。研究得出,外源有机酸能够在一定程度上促进黑麦草地上部分和根系干物质量的增加,黑麦草根系对Pb2+的吸收富集效果大于地上部分,有机酸的加入活化了土壤中的Pb2+,促进了植株对Pb2+的吸收富集。黑麦草根际土壤pH、Eh值和Pb2+残留量均小于非根际。酒石酸、苹果酸和丙二酸既不影响黑麦草植株生长,又可有效增加其对Pb2+的吸收富集,主要是增加地上部分对Pb2+的吸收富集;冰乙酸可显著活化土壤中的Pb2+。In order to discuss the effect of organic acid exudation from root on the absorption and accumulation of Pb2＋ by plant,oxalic acid,glacial acetic acid,malonic acid,tartaric acid and malic acid were added into soil under 500 mg/kg of Pb2＋ content.And the content of organic acid was 1,3,5,6,7 mmol/kg.The rhizobox method was used to study the growth and development index of ryegrass,physicochemical properties of soil in rhizosphere and non-rhizosphere and the effect of absorption and accumulation by ryegrass in simulation greenhouse.The results indicated that the exogenous organic acid could improve the dry weight of shoot and root to some extent.The absorption and accumulation effect of Pb2＋ by root was greater than shoot.And the activation of heavy metal was increased when added the organic acid.And the organic acid can promote the absorption and accumulation of Pb2＋ by plant.The value of pH,Eh and residual quantity of Pb2＋ in rhizosphere was less than non-rhizosphere.Tartaric acid,malic acid and malonic acid could promote the absorption and accumulation of Pb2＋ by plant,the effect was obvious on shoot,but there were not bad influence on the growth of ryegrass.Glacial acetic acid could increase the activation of heavy metal in soil markedly.

关 键 词：黑麦草 PB 有机酸 根际 非根际 

分 类 号：X53[环境科学与工程—环境工程]