Waterlogging Induces High to Toxic Concentrations of Iron, Aluminum, and Manganese in Wheat Varieties on Acidic Soil

ABSTRACT

Six wheat varieties with different tolerance to waterlogging were studied in acidic soil (pH 4.5), neutral soil, and potting mix (pH 6.7–7.8) under controlled conditions. Waterlogging for 49 d reduced shoot dry weight by 48% to 85% compared with drained treatments. The ranking of varieties for waterlogging changed under different soils, and this change explains why waterlogging tolerance of these varieties may vary in different environments. In waterlogged acidic soil, shoot concentrations of aluminum (Al), manganese (Mn), and iron (Fe) increased by two- to 10-fold, and in some varieties they were above critical concentrations compared with plants in drained soil. These elements decreased or remained the same in shoots of plants grown in waterlogged neutral soil. Marginal nitrogen (N) deficiency was induced in most varieties in all soil types. The results support the importance of screening in soils from the target environment for accurate germplasm characterization for waterlogging tolerance.

Keywords:

• waterlogging
• wheat
• aluminum
• manganese
• iron
• nitrogen deficiency
• microelement toxicity

ACKNOWLEDGMENTS

This work has been part of the ACIAR project CS1/1996/025, “Physiological and Genetic Approaches for the Development of Waterlogging Tolerance in Wheat on Sodic/Alkaline and Neutral Soils in India and Australia”. We wish to thank Jessica Sheppard and Glenn McDonald from teh Department of Agriculture, Katanning, for providing detailed information on waterlogging-prone sites and assistance in soil collection from Holly Siding and Wemyss Estate, Western Australia. Thanks to Professor Z. Rengel for the supply of UWA potting mix. We thank Ben Biddulph for his assistance and experimental support and Colin Hanbury for his useful editorial comments on an earlier version of this manuscript.