Biofortification with selenium and implications in the absorption of macronutrients in Raphanus sativus L.

It is well known that selenium (Se) is an essential element for humans, presenting antioxidant functions. This study aimed to evaluate the efficiency of Raphanus sativus L. as an agricultural crop indicated for selenium biofortification and to investigate the influence of different sources and forms of application on Se accumulation and macronutrient absorption. The experiment followed a randomized complete design with five replicates, arranged in a 2 x 2 + 1 factorial scheme, consisting of two sources of Se (sodium selenate and sodium selenite) and two forms of application (application in the soil at the dose of 1.2 mg kg(-1) of Se and foliar application at the dose of 50 mu mol L-1 of Se), with a control treatment without the addition of selenium. The accumulations of Se in the leaf, root, and whole plants were higher with the selenate source applied via soil when compared with the foliar application. For the selenite source applied via soil, Se root contents were higher when compared with the fertilization via leaf. The Se content in the root was lower for the selenate applied via soil when compared with the other treatments and the control. Raphanus sativus L is an agricultural crop suitable for the agronomic biofortification of selenium, since it concentrates the appropriate levels of Se in the roots and leaves, not harming the crop yield. The application of Se in the form of selenate and via soil was the best technique to increase the contents of Se in the plant, without causing damages in the accumulation of biomass, despite having led to a reduction in the accumulation of S.