Alterações fisiológicas e bioquímicas em sementes de arroz sob diferentes condições de armazenamento

Abstract

Seed storage has become is an essential activity, whose function is to maintain the quality of seed for the next sowing. Rice seeds (Oryza sativa L.) can be stored either in sacks as bulk, seeking to preserve your physiological quality, through conditions where damage seeds are minimal. Therefore, this experiment aimed at evaluate the influence of temperature during storage on the physiological quality of rice sseds, cv BR- IRGA 417, and verify changes in chemical compositions and activity of hydrolytic enzymes. For that, rice seeds were submitted to four storage conditions, without humidity and temperature control (laboratory), contant temperature of 15 ºC, temperature of 15 ºC with rise temperature to 25 ºC during 24 hours, every seven day storage, and temperature of 15 ºC with rise temperature to 25 ºC during 24 hours, every 14 day storage, remain stored for 168 days and evaluated at regular intervals of 56 days. The following testes were performed: germination test, first count of germination, germination speed rate, shoot and root length, dry mass of shoot and root, electrical conductivity, in all periods, already the following tests: chemical composition, and determining the activity of α-amylase and phosphatase acid, as well as parameters obtained in the emergency seedlings test, were carried out before starting storage and after 168 days. The results showed that during storage temperature alternation causes reduction in the seed physiological quality. Therefore, it can be concluded that though maintaining high germination potential occurs reduction in the effect of rice seeds cv BR-IRGA 417, when stored under unsuitable temperature conditions.