Tecnologias de pós-colheita em sementes de Braquiária híbrida cv. Mulato II

Abstract

Due the importance of forage species it is relevant the improvement of technologies to add greater quality seeds and provide a faster response to the investments made. Thus, whereas the treatment phytosanitary, the coating and storage has an important role in maintaining the seed quality. The aim in this research was study the physiological changes that occur in Braquiária híbrida cv. Mulato II (Urochloa brizantha x Urochloa decumbens x Urochloa ruziziensis) seeds submitted to technologies of scarification, chemical treatment and coating during the storage. The high temperature and humidity for up to 48 hours favors the germination of scarified seeds of Brachiaria híbrida cv. Mulato II, increasing the α-amylase enzyme expression and reduces the electrical conductivity values. There is loss of vigor when scarification seeds of Braquiária híbrida cv. Mulato II are exposed to high temperature and humidity for 96 h, with changes in enzyme systems and increased respiratory rate. The chemical treatment with Cruiser and Maxim influence negatively the viability, respiration rate and enzyme system of Braquiária híbrida cv. Mulatto II seeds. The chemical treatment with Cruiser and Maxim not affect positively the germination the seeds of Braquiária híbrida cv. Mulato II. However, when products are associated there are no increases in the percentage of germinated seeds. The conventional environment favors overcoming the physiological dormancy of Braquiária híbrida cv. Mulato II seeds, but as a result increases the seed deterioration. Braquiária híbrida cv. Mulato II stored under refrigerated (13 ± 3 ° C) have their dormancy preserved for 360 days. The coating retards the germination and enhances the expression of alcohol dehydrogenase enzyme in Brachiaria híbrida cv. Mulato II during storage.