Qualidade fisiológica e expressão enzimática de sementes de soja RR®

Abstract

The herbicide glyphosate affects soil quality bio indicators and morph physiological and nutritional aspects of RR® soybean plants. However, to the best of our knowledge, the impact of these physiological effects on the quality of RR® soybean seeds is not known. The expression of enzymes is related to quality of soybean seeds according to the genotype and production environment. The aim of this study was to evaluate the physiological quality and the enzymatic activity of RR® soybean in two production environments as a function of glyphosate doses. The seeds were produced in the 2014/15 crop in Lavras and Patos de Minas in a factorial 3 x 6, three soybean RR® cultivars a function (CD 250, TMG 1174, V-MAX) and six doses of the herbicide glyphosate (0, 960, 1920, 2880, 3840, 4.800 g e.a. ha-1). The harvested seeds were analyzed in the laboratory and enzyme expression as well as water content, germination (in sand and in paper), seedling emergence, emergence speed index, electrical conductivity, accelerated aging and vigor and seed viability. A completely randomized design was adopted. The application of increasing doses of glyphosate up to 4.800 g a.e. ha-1 do not affect the physiological quality of soybean seeds. There was no effect of increasing rates doses of glyphosate on the enzymatic expression of esterase, alcohol dehydrogenase, malate dehydrogenase and catalase. Cultivar V-MAX RR presented 80% of germination in sand with the seed marketing standards in Brazil.