MOLÉCULAS SINALIZADORAS PARA INDUÇÃO DE TOLERÂNCIA A ESTRESSES ABIÓTICOS EM SEMENTES DE SOJA

Abstract

Soybean culture is emerging as one of the most important Brazilian commodities, and new technologies have been incorporated into production systems and genetic improvement programs to improve its seed quality. In this sense, the physiological conditioning of soybean seeds presents itself as a promising alternative, aiming to benefit the seedling germination and emergence, especially under less favorable conditions, such as drought and extreme temperatures. Thus, this paper aimed to study the efficiency of using signaling molecules to induce the tolerance to abiotic stresses in soybean crop, using physiological conditioning in seeds of two cultivars, cultivar I (early) and cultivar II (late). The seeds from the 2020/2021 harvest were taken to the laboratory and submitted to physiological conditioning with two conditioning substances, the nitric oxide and the hydrogen peroxide, then, submitted to high temperature stress at 38 ºC and water restriction induced by Polyethylene glycol solution (PEG). After the treatments, the seed physiological quality was evaluated by the test of moisture content, first germination count, final germination, length of primary and secondary roots, hypocotyl size, and total growth. A completely randomized design was used with a double factorial scheme 3 x 2 x + 1, three treatments (nitric oxide, hydrogen peroxide, and normal condition), two stresses (water and temperature), in addition to the control for each cultivar. The Dunnett test was carried out to compare the control with the treatments resulting from the factorial when significant. Conditioning using the signaling molecules of nitric oxide and hydrogen peroxide does not reduce the germination potential of soybean seeds. Soybean seed conditioning does not contribute to the development of seedling primary and secondary roots for both cultivar I and cultivar II.