Vigor and anaerobic metabolism of soybean seeds evaluated by ethanol test

Abstract

Among the vigor tests, ethanol is an alternative that provides desirable characteristics to be applied in seed-producing companies internal quality control planning. The aim was to evaluate the vigor of soybean seeds by the ethanol test and the fermentative metabolism after its application. A completely randomized experimental design with five replications was used, with treatments consisting of 10 lots of soybean seeds, except for the variables composing the fermentative metabolism, for which five lots of soybean seeds were used. First, the initial quality of the lots was assessed by evaluating water content, germination, seedling emergence, accelerated aging, tetrazolium test (vigor), electrical conductivity, and seed respiration. For the ethanol test, the seeds were subjected to soaking times of 30, 60, 90, and 120 minutes until the moment of reading, and subsequently, the fermentative metabolism was evaluated (lactate dehydrogenase - LDH, pyruvate decarboxylase - PDC, and alcohol dehydrogenase - ADH). The ethanol test in soybean seeds efficiently ranks lots into different levels of vigor, using the soaking time of 30 minutes, showing a moderate association between the electrical conductivity test and seed respiration. Furthermore, the activity of the enzymes LDH, PDC, and ADH proves that ethanol is produced during the soaking process of soybean seeds.