QUALIDADE DAS SEMENTES DE CEVADA EM FUNÇÃO DA MATURIDADE FISIOLÓGICA: PARÂMETRO FISIOLÓGICO E EXPRESSÃO GÊNICA DIFERENCIAL DE ENZIMAS ASSOCIADAS À GERMINAÇÃO

Abstract

The germination of the barley seeds is essential for the production of malt and enzyme degradation of the starch to soluble sugars, makes part of this seed germination process. The objective of this study was to evaluate the physiological parameters of barley seeds, from germination and vigor tests, depending of the harvests close to physiological maturity, stored or not, and the influence of the differential expression of the genes which codify to α amylase and β-amylase enzymes. The seeds of BRS Cauê and Irina were cultivate in 2017 and harvested at 99 (32% water), 104 (19.18% water), 107 (17.92% water) and 114 (15.89% water) days after sowing (DAS) to BRS Cauê and 102 (32.76% water), 107 (20.27% water), 121 (13.63% water) and 127 (17.43 % water) DAS to Irina. The seed quality was evaluated immediately after harvesting and storage for 111 days (BRS Cauê) and 107 days (Irina). The seeds kept dormancy, mainly in the initial evaluation; (15.89% water) for seeds from BRS Cauê and 107 (20.27% water) for Irina, without variation in the quality of the seeds evaluated after storage. The differential expression level of gene coding to α-amylase, to the seeds of BRS Cauê harvested at 114 DAS, was higher, regardless of the evaluation time and the 99 DAS. For Irina the highest levels of expression were obtained when the seeds were harvested at 127 DAS. The level of expression of the gene coding to β-amylase was higher for seeds harvested at 99 DAS for BRS Cauê and 102 DAS for Irina initially evaluated, with decrease after storage. Seed dormancy favored the maintenance of seed quality, regardless of when they were harvested. It is not possible to establish a correlation between the results of germination and vigor tests of barley seeds and gene expression for this experiment, evidencing the complexity of this relationship and the requirement for research that can better elucidate it.