低分子量有教材机酸对硬质小麦根际环境中重金属的活化作用.pdf

Plant and Soil 203: 109–117, 1998. 109 © 1998 Kluwer Academic Publishers. Printed in the Netherlands. Low-molecular-weight organic acids in rhizosphere soils of durum wheat and their effect on cadmium bioaccumulation ´ ´ 1 23 2 2 2 G. Cieslinski , K.C.J. Van Rees , A.M. Szmigielska , G.S.R. Krishnamurti and P.M. Huang 1Research Institute of Pomology and Floriculture, 96–100 Skierniewice, Pomologiczna 18, Poland and 2Department of Soil Science, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada S7N 5A8. 3 Corresponding author Received 16 December 1997. Accepted in revised form 24 June 1998 Key words: cadmium bioaccumulation, durum wheat, organic acids, rhizosphere Abstract Cadmium (Cd) accumulation has been found to vary between cultivars of durum wheat (Triticum turgidum var. durum), and it is hypothesized that low-molecular-weight organic acids (LMWOAs) produced at the soil-root interface (rhizosphere) may play an important role in the availability and uptake of Cd by these plants. The objective of this study, therefore, was to (1) investigate the nature and quantity of LMWOAs present in the rhizosphere of durum wheat cultivars Arcola (low Cd accumulator) and Kyle (high Cd accumulator) grown in three different soils: Yorkton, Sutherland and Waitville, and (2) determine the relationship between Cd accumulation in these plants and LMWOAs present in the rhizosphere. Plants were grown for two weeks in pot-cultures under growth chamber conditions. Oxalic, fumaric, succinic, L-malic, tartaric, citric, acetic, propionic and butyric acids were found and quantified in the water extracts of rhizosphere soil, with acetic and succinic acids being predominant. No water e