Evaluation of Mechanisms of Phosphorus Use Efficiency in Traditional Wheat Cultivars for Sustainable Cropping

Abstract

In order to search for low input alternative wheat cultivars, this study aims to investigate the mechanisms of phosphorous (P) uptake and utilization efficiency of two traditional wheat cultivars as compared to a modern cultivar. The experiment was conducted under semi-controlled conditions using four P supplies. Plant growth and P efficiency parameters were studied at two harvest dates. Plant and soil parameters where measured: shoot dry matter, P concentration in shoot, root length, root diameter, specific root density, root length/shoot weight, shoot growth rate, P shoot demand on roots, P influx, P efficiency ratio, P utilization index, extractable and soil solution P concentrations, and P recovery. Traditional and modern cultivars had similar overall uptake (P influx, and recovery) and utilization efficiency. In terms of specific efficiency traits, traditional cultivars had the superiority in having more root size, higher root shoot ratio, slower shoot growth rate and less shoot demand on roots for P, but were inferior in having thicker roots and less specific root density. Investigating P use efficiency mechanisms could be a useful tool in selection programs to separate plant cultivars to superior and inferior, but using different measures of utilization efficiency parameters could be in some cases misleading.