Characterization of genotype variation and agronomic biofortification of cowpea with selenium: impacts on phytic acid and nutritional quality of grains

Author(s)

Vinicius Martins Silva

• Document type: Master's Dissertation
• Press: Ilha Solteira. 2019-02-11.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira
• Defense date: 2019-02-05
• Advisor: André Rodrigues dos Reis; Marco Eustáquio de Sá

Abstract

Selenium (Se) is a nutrient for humans and animals, and a beneficial element for plants, its low concentration in Brazilian soils might cause deficiency in animals and humans. Phytate is the main form of phosphorus (P) storage found in plant seeds, being considered an "anti-nutrient" by forming nondigestible complexes with nutrients such as Fe, Ca and Zn. Thus, there is a need to find alternatives to increase Se and decrease phytate concentration in the edible parts of modern cultivars. The objective of this study was to evaluate optimal levels and sources of Se to be applied in Brazilian conditions, as well as the influence of the Se in the production and nutritional quality in 29 genotypes of cowpea. Two experiments were performed: Experiment 1: The efficiency of agronomic biofortification was evaluated using 2 sources of Se (selenate and selenite) and 7 levels of Se (0; 2.5; 5.0; 10.0; 20.0, 40.0 and 60 g ha-1) applied via soil, phytate analysis was analyzed. Experiment 2: An experiment was carried out to characterize the uptake and accumulation of Se, phytate, sugars, storage proteins and amino acids in the grains of different genotypes of cowpea. In this experiment, 29 genotypes were evaluated in the presence and absence of Se (0 and 25 g ha-1), grown until the end of the cycle to obtain the grains. In experiment 1, it was observed that the application of selenate provides higher concentrations of Se in the grains compared to selenite. Selenium application showed no direct influence on the phytate concentration in the grains. In experiment 2 it was observed that the application of Se increased the concentration of the element in roots, shoot and grains of all evaluated genotypes. Se application may provide increase, decrease or not influence the content of phytates, sugars, reserve proteins and amino acids, depending on the genotype. (AU)

• FAPESP's process: 16/19773-8 - Characterization of genotypic variation and agronomic biofortification of cowpea plants with selenium to improve nutritional quality and low phytate content in grains
• Grantee: Vinicius Martins Silva
• Support Opportunities: Scholarships in Brazil - Master