Early evaluation of root morphology of maize genotypes under phosphorus deficiency

In Brazil savanna type of soils presents problems with phosphorus content. The selection and identification of maize genotypes to such environments is a high priority of Brazilian research. The purpose of this paper was to evaluate, in soils with different P concentrations, the dry mass attributes and characteristics of root morphology in eight maize lines with different genetic background and origins of the Breeding Program of the National Research Center for Maize and Sorghum. The experiment was carried out in plots prepared with two levels of phosphorus: high phosphorus (HP) and low phosphorus (LP). The experimental design was randomized blocks with three replications. The evaluation of the characteristics of the shoots and the root system morphology was performed 21 days after sowing. The WinRhizo program of images analysis was used for the root morphology. There were no differences between the phosphorus levels for the dry mass attributes. However, when we compared P levels, root morphology of L13.1.2 strain performed the highest surface area (SA) and total root length (RL), length of thin (TRL) and very thin (VTRL) roots in low P concentration. The root systems digital images analysis techniques allowed efficient discrimination of maize genotypes in environments with low P levels.