Biofortificação agronômica com selênio em variedades de arroz do Pantanal Mato-Grossense e sua acessibilidade in vitro

Abstract

Selenium (Se) is recognized as an essential micronutrient for animals and humans, which can contribute to human immunity and prevent chronic noncommunicable diseases. As a staple crop, rice (Oryza sativa L.) is the main cereal produced and consumed in the world. The production of rice enriched with Se can be one of the ways to supply it to the population. There is scientific evidence that rice is capable of absorbing Se in the soil and therefore, this research was developed with the objective of evaluating plant growth, grain production and Se accumulation in three rice varieties in response to Se application in the soil and to evaluate the in vitro availability of Se in the rice grains of the three varieties evaluated in the study. For this, the study was divided into two stages. In the first one, three varieties of rice were used, one commercial (cv. Esmeralda) and two ethnovarieties from the Pantanal MatoGrossense (var. Branquinho and Agulhinha Vermelho) and the treatments of selenium doses (0, 5, 10, 15 , 25 and 50 g ha-1 ), in the form of sodium selenate. At the end of the experiment, plant height (m), panicle length (cm), shoot and root dry mass (g pot-1 ), grain production (g pot-1 ), Se content in the grains (μg kg-1 ), use of Se applied by grains (%). In the second stage, two ethnovarieties from the Pantanal MatoGrossense (Branquinho and Agulhinha Vermelho) and a commercial grow crops (Esmeralda) were used, agronomically biofortified with sodium selenate (50 g ha-1 ) and grain production (g plant-1 ), total phenolic concentration (µg GAE 100 g-1 MS), total Se (µg 100 g-1 MS), Se after TGI (gastrointestinal simulation) (µg 100 g-1 rice) and Se accessibility (%). In the first stage of the study, the rice ethnovarieties, Branquinho and Agulhinha Vermelho, showed similar behavior to the commercial grow crops Esmeralda, in terms of agronomic biofortification. Plant growth increased in response to Se application in the soil, showing an increase in grain yield in all evaluated rice varieties. The concentration of Se in rice grains increased, as doses of Se were supplied via soil, for all varieties used. At the highest applied dose, the Se content found in rice grains may contribute with part of the recommended daily intake (IRD) of Se, considering the daily per capita consumption of 108 g of rice, which is equivalent to about 10% of the needs Se daily for an adult individual. The efficiency of use of Se applied via soil, by polished rice grains, for all varieties used, were low in relation to the evaluated Se doses (0 to 3,4%). The effects of Se on the evaluated agronomic characteristics were dependent on the dose applied to the soil. In the second stage of the study, the ethnovarieties showed higher g plant-1 production and total Se concentration in relation to the commercial cultivar, Esmeralda. All genotypes showed Se accessibility greater than 60%, it is noteworthy that the commercial cultivar provided greater Se accessibility and content of phenolic compounds.