PRIMING COM BASSINOLIDE E NANOPARTÍCULAS DE SILÍCIO NO DESEMPENHO DE SEMENTES DE MILHO

Abstract

The use of high-quality and vigorous seeds is fundamental to increase agricultural productivity, being an essential factor for success of maize (Zea mays L.) cultivation. However, various challenges may compromise seed quality and plant development, such as seed deterioration and aging, as well as adverse environmental factors, including temperature fluctuations and water stress. These factors limit seed germination potential and vigor, hindering seedling growth and consequently affecting crop productivity. Maize productivity has been driven by new technologies, including the improvement of seed quality. Among the strategies employed, priming stands out as a technique that involves pre-conditioning seeds before sowing. This approach can increase germination speed and vigor, as well as to contribute to the early development of seedlings, especially under stress conditions, and allow the application of substances such as growth regulators and nanoparticles. This study investigated the potential of priming maize seeds using two distinct approaches: the use of brassinolide (BL) and silicon dioxide nanoparticles (SiO₂- NPs). Priming with BL (Experiment I) was performed using different concentrations (0.0, 0.5, 1, and 2 μM) to assess its effect on early seedling development, particularly under stress conditions. For this, germination tests, accelerated aging, and performance evaluation under stresses such as cold and water restriction were employed. Similarly, maize seeds were treated with different concentrations of SiO₂ nanoparticles (0, 200, 400, and 600 mg L-1) in Experiment II, the priming effect was analyzed through physiological and biochemical assessments. Both priming techniques were evaluated in relation to chlorophyll fluorescence tests, gas exchange, and other physiological parameters, such as α-amylase enzyme activity. These tests allowed the analysis of the priming effectiveness in improving seed vigor and resistance. The results indicated that both brassinolide and SiO₂ nanoparticles increased the physiological quality of the seeds, favoring germination and early seedling development, especially when seeds faced stress conditions.