Banca de QUALIFICAÇÃO: CRISTIAN BERNARDO DA SILVA

DEVELOPMENT AND PROOF OF CONCEPT OF A BIOSENSOR BASED ON THE TECHNOLOGY OF COLORIMETRIC DETECTION DEVICES ON PAPER FOR EVALUATING THE PHYSIOLOGICAL QUALITY OF SOYBEAN SEEDS

Lab-On-Paper, Vigour, Glycine max.

Low productivity, resulting in losses in the production chain of seed-disseminated crops, reflects a series of degenerative changes and consequent reduction in physiological potential and quality after maturity. Monitoring the physiological potential of seeds throughout all stages of production and storage, through the evaluation of batch vigor, provides important information and enables faster decision-making. Considering the socioeconomic importance of soybean cultivation and the assessment of seed vigor, this doctoral thesis project has been developed, presented here with three key objectives. Firstly, a systematic effort is made to map future scientific and technological developments capable of significantly influencing the seed sector. Secondly, through the study of seed deterioration using methods standardized by RAS, particularly in the evaluation of germination and physiological quality, the aim is to obtain auxiliary tools in seed analysis and promote the highest possible physiological quality. Lastly, to increase the participation of national technology in seed vigor assessment by analyzing the economic viability of physiological analysis of soybean seed lots using biosensors and evaluating their results with statistical tools. Analysis of data from the world's leading patent databases reveals that there is still little investment in industrial protection (patents) for technologies in seed vigor assessment. By analyzing the results of parameters such as pH, glucose content, potassium ions, and electrical conductivity in mass tests of soybean seed exudate after 24 hours of imbibition in deionized water, it is possible to demonstrate that the decrease in vigor and germination is directly proportional to the increase in leaching of cellular solutes from the seeds, suggesting an intimate relationship between membrane integrity and loss of vigor and germination. This could lead to their assessment based on the permeability of cell membranes, involving parameters related to the release of metabolites during seed imbibition. Their application in low-cost biosensors could assist producers more efficiently based on the results obtained during use.