Phosphorus efficiencies and their effects on Zn, Cu, and Mn nutrition of different barley (Hordeum vulgare) cultivars grown in sand culture

Abstract

<jats:p> A sand-culture experiment was carried out in a growth chamber to investigate the phosphorus (P) efficiencies of 8 barley cultivars that are parents of 4 mapping populations, and the effects of P nutrition on plant uptake of zinc (Zn), copper (Cu), and manganese (Mn). Two sources of phosphate were used, rock phosphate (sparingly soluble) and CaHPO4 (readily available). There were significant differences in P uptake and utilisation efficiencies between the 8 cultivars. Among the cultivars, the Sahara–Clipper pair is of the most interest, because these 2 cultivars had large differences in root/shoot ratios, P allocation between root and shoot, and P uptake/utilisation efficiencies. Higher P availability significantly reduced plant Zn uptake and tissue concentrations in all cultivars. Shoot Zn concentrations were found to decrease significantly with P influx to the xylem (P &lt; 0.01), indicating that genotypic variations in P translocation from roots to shoots may interact with Zn accumulation in shoots. Higher P availability reduced Cu concentrations in shoots, probably due to a dilution effect. P availability (rock phosphate v. CaHPO4) seemed to affect plant uptake of Mn in some cultivars, but further study is needed to elucidate the mechanisms involved and the practical implications of this interaction in Mn-deficient soils. </jats:p>