There are conclusive evidences of selenium deficiency in Brazilian soils, which can lead selenium deficiency in plants, animals and humans. Thus, is needed to increase the Se content on edible parts of modern cultivars, because the highest yield has shown a low micronutrient content and poor nutritional food quality of cereals. This study aim to evaluate the influence of selenium on yield and nutritional quality in cowpea beans genotypes and to establish optimal levels of selenium to apply in Brazilian environemtal conditions. To achieve our propose, the following experiments will be carried out: Experiment 1: Based on our previous studies on selenium accumulation in plants (Reis et al., 2013), an experiment will be conducted to characterize the efficiency of absorption, translocation and accumulation of selenium in different genotypes of cowpea beans. In this experiment, 30 different cowpea genotypes will be cultivated in the absence and presence of selenium (0 and 0.3 mg kg-1), with 4 replicates. All plants will be grown in a greenhouse by the end of life cycle to obtain the cowpea beans for chemical analysis. Experiment 2: The efficiency of agronomic biofortification will be evaluated using two contrasting cowpea genotypes (high and low selenium accumulation in beans based on results of Experiment 1) and 6 levels of selenium (0, 10, 25, 50, 100 and 150 g ha-1) applied via soil using sodium selenate as source. The content of nutrients, organic forms of selenium (selenocysteine and selenomethionine), total amino acids, protein and sugars of beans harvested from Experiment 1 and 2 will be analyzed. The mechanisms involved in genetic variation on selenium accumulation and its traits related to crop response to selenium fertilizer can provide a poweful information for further plant breeding and fertilizer management to improve food nutritional quality.
News published in Agência FAPESP Newsletter about the scholarship: