Kinetics and translocation of phosphorus in maize hybrids

Abstract

The objective of this work was to study the P absorption and P translocation in maize (Zea mays, L.) hybrids, grown at two P levels. Plants of three maize hybrids grown in nutrient solution with 0.02 mM and 0.10 mM of P were submitted to a P depletion experiment and to a P translocation experiment. The kinetic parameters (Imax, Km and Cmin), the weight and the P content of xylem exudate, and the P translocation from roots to shoots were evaluated. The reduced P level in nutrient solution increased Imax but without changes in Km e Cmin. Phosphate starvation decreased the weight and the P content of xylem exudate and the P translocation from the roots to the shoots in all hybrids. The hybrid BR 201 showed higher net influx rate, Imax and P content in xylem exudate at low P level when compared with the other hybrids.