Absorção de cálcio e magnésio por cultivares de aveia submetidas a níveis de toxidez por alumínio

Abstract

Acid soils with high aluminum (Al) concentrations affect the productivity of oats and many crops. The toxicity of this cation, besides reducing root growth, interferes on the uptake, transport and use of nutrients such as magnesium (Mg) and calcium (Ca). The objective of this work was to evaluate the Ca and Mg uptake ability by measuring their content in the leaf tissues of white oat cultivars. Tolerant and sensitive cultivars were tested under hydroponic culture to verify if the genotypes with greater uptake ability of Ca and Mg do represent those with a tolerant response. In the study, two experiments were performed, one to validate the tolerance groups based on root regrowth and another aiming to reach plant dry masses large enough to determine Ca and Mg. In both situations, the experimental design was completely random at a 3 x 6 factorial for dose and genotype with three replications. The uptake of Ca and Mg are affected by the addition of Al to the hydroponic solution, with tolerant cultivars showing higher concentrations on the leaf tissues than sensitive ones in the absence and presence of Al. Therefore, there is a link between the tolerance levels with the Al uptake, representing a variable to be employed on the selection of more efficient genotypes.