ABSTRACT The mobilization of reserves determines the formation of seedlings during germination, being influenced by seed vigor and adverse stress conditions. Seeds with higher vigor have greater potential for mobilization of reserves, and it can favor performance under conditions of salt stress. The objective of this study was to identify how the mobilization of reserves stored in common bean seeds contributes to the overcoming of salt stress, seeking to identify the difference in hydrolysis and mobilization of reserves among seeds with superior vigor. Seeds from two genotypes contrasting in vigor (BAF44 and BAF55) were used. Salt stress was simulated using sodium chloride, and evaluations were performed at one, three, five and seven days of germination. The variables analyzed in seedling was length, dry mass, and metabolic expenditure, while biochemical analyses of total starch, total protein, total soluble sugars, total soluble proteins, and alpha-amylase activity were evaluated in the embryonic axis and/or cotyledons. The salt stress condition negatively affected the performance of the seedlings, resulting in a decrease in length, mass accumulation, and reduced use of seed reserves, associated with a lower hydrolysis of starch and proteins. Seeds with higher vigor showed higher dry mass and seedling length even when subjected to salt stress conditions, because of greater hydrolysis capacity and use of soluble proteins and soluble sugars, which result in seedlings with better performance under control and salt stress conditions. germination BAF44 BAF (BAF4 BAF55 used chloride one three expenditure protein sugars alphaamylase alpha amylase andor or cotyledons accumulation BAF4 (BAF BAF5

ABSTRACT Seed vigor is one of main attributes of the physiological quality from seed lot. Thus, identify which mechanisms are used by seeds of higher vigor that favor the formation of seedlings with better performance is a key aspect in agriculture. The enzyme activity of phytase and alpha-amylase favor the availability of phosphorus and sugars, respectively, during germination and can be determinants of seed vigor. Thus, the objective of the present work was to identify the association of phytase and alpha-amylase enzymes with the vigor of a seed lot of common beans. The results showed a positive correlation between seed vigor and the enzymes evaluated. Based on the findings, it can be concluded that seeds with high vigor have a high capacity to form seedlings with better performance, because they present high enzymatic activity. Also, in seed lots of the same genotype, they can be used to determine seed vigor during germination. Thus agriculture alphaamylase alpha amylase sugars respectively beans evaluated findings Also genotype

ABSTRACT Under stressful conditions, the use of high-vigor seeds is a relevant alternative to reduce losses, as they can germinate in a wide range of environmental conditions. However, it is necessary to understand the biochemical strategies adopted by high-vigor seeds to achieve better performance during periods of stress. Thus, the objectives of this research were to evaluate the tolerance of maize seeds of contrasting vigor subjected to different levels of stress due to accelerated aging and to verify whether differences in antioxidant metabolism and starch reduction explain the differences between vigor levels. The experiment was conducted with a high-vigor seed lot and a low-vigor seed lot, in a completely randomized design. The lots were subjected to 0, 24, 48, 60 and 72 hours of accelerated aging (45°C and 100% relative humidity), and after that the tests were carried out. The variables analyzed were the percentage of normal (first and second count) and abnormal seedlings, dead seeds, vigor index, electrical conductivity, total soluble sugars in the leachate, alpha-amylase activity, soluble sugar content, catalase activity, peroxide hydrogen, lipid peroxidation, proline, and carotenoid content. High-vigor seeds better tolerate stress conditions caused by high temperature and humidity. The higher content of total soluble sugars and alpha-amylase activity may explain the better performance of high-vigor seeds. highvigor losses However Thus lowvigor low design 0 24 48 6 7 45°C 45C C 45 100 humidity, humidity , humidity) out first count seedlings index conductivity leachate alphaamylase alpha amylase hydrogen peroxidation proline Highvigor High 2 4 10 1