Qualidade fisiológica de sementes de berinjela osmocondicionadas

Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15º C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15º C and 25º C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30º C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15º C or 25º C for 24, 48 or 72 hours

Desempenho fisiológico de sementes de cagaita (Eugenia dysenterica DC.) Submetidas à secagem

The present study aimed to determine the imbibition curve and evaluate the effects of ‘reducing the water content of cagaita seeds (Eugenia dysenterica DC.), using the radiographic image analysis technique. To this end, three assays were carried out: seed imbibition curve and root protrusion were determined in assay 1. Seeds in silica gel were oven dried for to 72 h and were then analyzed for water content and vigor in assay 2. Seeds were dried up to certain levels of the water content and were evaluated by radiographic imaging analysis in assay 3. A rapid mass gain was observed in the first 60 imbibition hours and the root protrusion reached 94.4% after 192 imbibition hours. Cagaita seeds did not tolerate drying periods longer than 24 h, which corroborates the recalcitrant behavior of the seeds of these species. The analysis of the radiographic image obtained by an X-ray test allowed the establishment of a direct relation between the increased free space area within the seed and the decrease in the seedling emergence. The drying process altered the internal morphology of the seed and such changes directly influenced the development of the seedlings.Objetivou-se com este trabalho determinar as relações entre níveis de absorção de água e a germinação, bem como, avaliar os efeitos da redução do teor de água no vigor de sementes de cagaita (Eugenia dysenterica DC.). Para tanto, foram realizados três ensaios: No ensaio 1 determinou-se a curva de embebição e germinação das sementes. No ensaio 2 as sementes foram submetidas a secagem em estufa e em sílica gel por até 72 horas e submetidas a avaliações do teor de água e do vigor. No ensaio 3 as sementes foram submetidas a secagem até determinados teores de água e avaliadas por meio da análise de imagens radiográficas. Houve um rápido ganho de massa nas primeiras 60 horas de embebição, com protrusão radicular chegando a 94,4% após 192 horas de embebição. As sementes de cagaita não toleraram secagem por períodos superiores a 24 horas, reafirmando o comportamento recalcitrante das sementes da espécie. A partir da análise de imagens radiográficas, obtidas pelo teste de Raios X, foi possível estabelecer relação direta entre o aumento da área de espaço livre no interior da semente, e a diminuição da emergência de plântulas