Variabilidade genética em linhagens de arroz para biofortificação com selênio

Abstract

Currently, approximately 90% of the countries have some malnutrition in their population, be it hunger or the denominated hidden hunger, a diet that presents itself as a non-explicit lack of one or more micronutrients in the body, resulting in nutrient deficiency. Researches have been conducted to minimize the effects of the malnutrition. Among the micronutrients studied, the use of selenium (Se), a mineral with high antioxidant potential, is essential for the functioning and maintenance of the organisms of living beings and beneficial to plants. Cereals such as rice (Oryza sativa L.) are prominent as crops cultivated and consumed on all continents, playing a strategic role in both economic and social aspects. The objective of this work was to verify the existence of genetic variability in upland rice strains regarding the capacity to absorb selenium and translocate it to the grain through agronomic biofortification. We evaluated 20 genotypes through the value for cultivation and use (VCU) derived from the upland rice breeding program of the Universidade Federal de Lavras. We conducted the experiments at the Fazenda Muquém (UFLA) and EPAMIG/Substation, in the municipality of Lavras. The experimental design was in randomized blocks employing plots subdivided in space with three replicates in the form of selenium application incorporated to urea in topdressing fertilization, with the effect of the application of a source sodium selenate at the dose of 80 g ha-1 of Se. We evaluated the characteristics of plant height, the weight of a thousand grains, income, whole grain yield, grain productivity, and selenium content in the grain and the plant shoot. The application of Se increased the yield of whole rice grains in both environments. We observed genetic variability regarding the accumulation of Se in the grain. Therefore, all genotypes were biofortified, reaching the maximum content of 2.58 mg kg-1 of Se in the grain. The results show that it is possible to increase the content of Se in rice through the application of selenium incorporated to urea, that is, if using this strategy to minimize the deficiency of this nutrient in the population since this element is little representative in most cultivated soils. Thus, this strategy is advantageous for not requiring changes in consumer behavior and not altering the appearance, taste, texture, or preparation form of the food. Thus, it is considered a viable, effective, and sustainable alternative to fight the malnutrition of underprivileged population and benefit their health.