Dormancy and enzymatic activity of rice cultivars seeds stored in different environments

Abstract

-The objective of this study was to assess the dormancy and the enzymatic activity of seeds of rice cultivars during storage in different environments. After harvesting, the seeds of two rice cultivars (BRS Ourominas and BRSMG Caravera) were dried in the sun, to reach a moisture content around 13%. Then, they were packed in paper and stored in four environments: 5 ± 2 °C / 70 ± 5% RH, 12 ± 2 °C / 70 ± 5% RH, 18 ± 2 °C / 65 ± 5% RH and in a natural condition. Germination and enzymatic activity were assessed at the beginning and at 3, 6, 9 and 12 months of storage. The experiment was conducted in split subplots in a completely randomized design with three replications. The dormancy of seeds stored in the natural environment was exceeded in a shorter time than the dormancy of seeds stored in cold. Catalase and ascorbate peroxidase activity increased during the storage period, the most obviously in storage in natural environment to cultivate BRSMG Caravera. The activity of the enzyme α-amylase decreased during the storage period.Index terms: enzymes, germination, Oryza sativa L. Dormência e atividade enzimática de sementes de cultivares de arroz armazenadas em diferentes ambientes RESUMO -O objetivo deste trabalho foi avaliar a dormência e a atividade enzimática de sementes de cultivares de arroz durante o armazenamento em diferentes ambientes. Após a colheita, as sementes das cultivares de arroz BRS Ourominas (várzea) e BRSMG Caravera (terras altas) foram secadas ao sol, até atingirem teor de água em torno de 13%. Em seguida, foram acondicionadas em embalagem de papel e armazenadas em quatro ambientes: 5 ± 2 °C/70 ± 5% UR, 12 ± 2 °C/70 ± 5% UR, 18 ± 2 °C/65 ± 5% UR e em condição natural. A germinação e a atividade enzimática foram avaliadas no início e aos 3, 6, 9 e 12 meses de armazenamento. O experimento foi realizado no esquema de parcelas subdivididas no delineamento inteiramente casualizado com três repetições. A dormência das sementes armazenadas em ambiente natural foi superada em menor tempo do que as sementes armazenadas em câmara fria. Houve aumento da atividade das enzimas catalase e ascorbato peroxidase, com maior evidência no armazenamento em ambiente natural, para a cultivar BRSMG Caravera. A atividade da enzima α-amilase diminuiu durante o período de armazenamento.Termos para indexação: enzimas, germinação, Oryza sativa L.

Storage time affects the germination and proteomic profile of seeds of Cariniana legalis (Mart.) O. Kuntze (Lecythidaceae), an endangered tree species native to the Brazilian Atlantic Forest

“…The observed reductions in moisture content and seed germination percentage during storage in this study could be associated with the low tolerance to seed desiccation in this species (Sousa et al 2016). Low desiccation tolerance has also been reported in other species (Beardmore et al 2008;Marques et al 2014;Dias et al 2016;Sena et al 2016). The proteomic analysis revealed differences in the abundances of proteins in several classes among the different times of storage, and we discuss our results in the context of the functional classifications of these differentially abundant proteins.…”

Alternative treatment to stimulate the germination of recently harvested wheat seeds

“…and after physiological maturity, temperatures significantly influence dormancy control in seeds; this was also observed in rice seeds (Marques et al, 2014). During seed formation, the exposure of plants to low temperatures induces dormancy, since a reduced temperature itself is essential to overcome dormancy after physiological maturity (Reddy et al, 1985).…”

“…A significant reduction was noticed in the percentage of dormant seeds in the tested genotypes, which is probably associated to the hormonal balance between germination promoters and inhibitors, such as gibberellin and abscisic acid (Bojovic, 2010;Tunes et al, 2011;Taiz and Zeiger, 2013;Liu et al, 2013;Gao and Ayele, 2014;Marques et al, 2014;Marcos-Filho, 2015). When gibberellin is in higher concentrations than abscisic acid and the environment is favorable to the germination process, germination will occur.…”

Effect of Temperature and Storage Period on Seed Germination and Some Morphological Characteristics of Rice (Oryza sativa L.) RD 6 cultivar

“…Low temperature decline seed deterioration that will cause low germination rate, survival rate and sensitive to stress environment [4]. Too high temperature and low temperature may cause ROS (Reactive Oxidation Species) accumulation that affect to hydrolytic enzyme activities such as protease, amylase, phosphatase, phospholipase and other enzyme [9] that importance for early embryo growth and development [10]. Moreover, optimal relative humidity is also significant for rice seed storaging because optimal relative humidity will induce seed softener that is useful for oxygen absorption and respiration in seed germination process.…”