title: Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).
abstract: Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio.
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
authors.forename: Xiwang
authors.initials: X
authors.lastname: Tang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Pang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
authors.forename: Puhui
authors.initials: P
authors.lastname: Ji
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Gao
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China; College of Resources and Environment, Thu Dau Mot University, Binh Duong, Viet Nam.
authors.forename: Thanh Hung
authors.initials: TH
authors.lastname: Nguyen
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China. Electronic address: tongyanan@nwsuaf.edu.cn.
authors.forename: Yan'an
authors.initials: Y
authors.lastname: Tong
mesh_terms: D002104:Cadmium / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis; D018545:Lactuca / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D036226:Seedlings / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis*; D013054:Spectrophotometry, Atomic
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: Accumulation; Bio-indicator; Cadmium contamination; Growing stage; Lettuce