Biofortificação genética e agronômica para enriquecimento de zinco em grãos de arroz: do arroz em casca ao arroz polido

Abstract

Approximately, 2 billion people in the world have some implicit deficiency of one or more micronutrient, also called hidden hunger. Therefore, research is being carried out in order to minimize the effects of this nutrition. Zinc deficiency is among the most prevalent mineral deficiencies in humans, affecting about 1.2 billion people, which can cause severe pathological conditions, such as growth retardation, dysfunction and cognitive impairment, suppressed immunity, pneumonia and eye injuries. Cereals such as rice (Oryza sativa L.) stand out for being consumed on all continents and social classes, playing an important socioeconomic role. Thus, the present study aimed to verify the existence of genetic variability and the potential for absorption of the Zn micronutrient, in grains of elite upland rice lines from different beneficiation processes, after the completion of agronomic biofortification. Five genotypes were obtained from the cultivation and use value tests (VCU), from the upland rice breeding program at the Federal University of Lavras - MelhorArroz. The experiments were conducted in the local of Lavras and Lambari in a randomized block design in a 5x2 factorial scheme, with three replications, season 2019/20. The following characteristics were evaluated: plant height, weight of a thousand grains, grain yield, percentage of whole grain yield, germination and accumulated Zn content in polished, brown and paddy rice. Genetic variability was observed regarding the accumulation of Zn in the grains, reaching a maximum of 47.39 mg kg-1 and 35.25 mg kg-1 of Zn in the whole and polished grains, respectively, in the ERF 85-15 genotype. It was found that the average contribution of the ERF 85-15 genotype, when performed a biofortification, in the daily intake of Zn when considering the average rice consumption of the world population was 63.6% and 47.4% in brown rice and polished, respectively. Thus, advanced combined genetic and agronomic biofortification strategies are advantageous in upland rice lines, being sustainable and effective in combating zinc deficiency, without requiring behavioral change from consumers.