Qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem

Abstract

Resumo -O objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem. Utilizaram-se sementes de berinjela, cultivar Embu, condicionadas em solução aerada de KNO 3 (-0,8 MPa), a 25ºC, por 48 horas. As sementes foram submetidas aos seguintes procedimentos: redução do teor de água inicial (r), choque térmico (CT) e secagem lenta (SL) ou rápida (SR) por 48 horas. As combinações desses procedimentos constituíram os tratamentos: sementes condicionadas e sem secagem, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL e rCTSR, além da testemunha (sementes sem condicionamento). As sementes condicionadas e as secas lentamente expressaram maior percentagem de germinação. Não houve diferença entre os tratamentos quanto à percentagem de emergência de plântulas. A testemunha levou mais tempo para alcançar a máxima emergência do que os demais tratamentos. As sementes submetidas ao choque térmico apresentaram maiores valores de condutividade elétrica do que as que não passaram por esse tratamento. A qualidade fisiológica das sementes de berinjela obtida com o condicionamento é mantida após a secagem. A secagem de sementes de berinjela condicionadas deve ser realizada preferencialmente de forma lenta, com ou sem redução do teor de água inicial.Termos para indexação: Solanum melongena, atividade enzimática, condicionamento fisiológico, microscopia eletrônica de varredura. Physiological quality of osmoprimed eggplant seeds subjected to dryingAbstract -The objective of this work was to evaluate the physiological quality of osmoprimed eggplant seeds subjected to drying. Eggplant seeds of the cultivar Embu, primed in aerated KNO 3 (-0.8 MPa) solution, at 25ºC, for 48 hours, were used. The seeds were subjected to the following procedures: reduction of initial moisture content (r), heat shock (CT), and slow (SL) or fast drying (SR) for 48 hours. The combination of these procedures formed the treatments: primed seeds without drying, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL, and rCTSR, besides a control (seeds without priming). Seeds primed and those dried slowly expressed higher germination percentage. No difference was observed among treatments for seedling emergence percentage. The control took more time to express maximum emergence than the other treatments. Seeds subjected to heat shock presented higher values of electrical conductivity than those that did not undergo this treatment. The physiological quality of eggplant seeds gained with priming is maintained after drying. The drying of primed eggplant seeds should be preferably performed slowly, with or without reduction of initial moisture content.

Physiological and biochemical changes during desiccation tolerance loss in millet (<i>Pennisetum glaucum</i> L.) seeds

“…The rapid drying technique on silica gel allows drying to a sufficiently low water content without adverse effects on seed viability and vigor (Varghese & Naithani, 2008). However, Reis et al (2013), who studied seed conditioning, stated that rapid drying could be harmful to seed vigor. For millet seeds dried on silica gel in the present study, the germination speed index of the seeds soaked for 3h did not differ from the control treatment (0h).…”

Influence of light, temperature and humidity on substrate and osmoconditioning during the germination of Mimosa bimucronata (DC) O. Kuntze.

“…When PEG + KNO 3 was used at a concentration of −1.0 MPa ( Figure 3B), an increase was observed in the germination percentage (82.89%) in lesser time (37 h of imbibition), which was calculated based on the equation regression. Thus, it is evidenced that changes in the osmotic potential of the solutions and in the conditioning periods correspond to variations in seed germination (Reis et al, 2013). These disagreements are due to the fact that the ideal relationship between the osmotic potential and the conditioning period varies according to the species.…”