Evaluation of pea seed vigor by the accelerated aging and controlled deterioration tests

Vigor tests were developed to detect differences in seed lots due to limitations of germination tests. The objective of this work was to investigate the efficiency of the accelerated aging and controlled deterioration tests to assess the vigor of pea seed lots. The water content and physiological quality of five pea lots cv. Aragon were determined using the germination and vigor tests (first count, electrical conductivity, seedling emergence and speed of emergence index, accelerated aging with the traditional system and with saturated NaCl solution at 41ºC for 48, 72 and 96 hours; and controlled deterioration test with 15, 20, 25% water content for 48, 72 and 96 hours at 42ºC). The accelerated aging test with saturated NaCl solution for 96 hours was efficient to categorize pea seeds lots. Combinations of 20% water for 72 hours and 25% water for 48 and 72 hours were efficient to categorize pea seed lots using the controlled deterioration test

Vigor of lentil seeds evaluated by the tests of accelerated aging and controlled deterioration / Vigor de sementes de lentilha avaliadas pelos testes de envelhecimento acelerado e deterioração controlada

The objective of this work was to investigate the efficiency of the accelerated aging and controlled deterioration tests in the evaluation of lentil seeds’ vigor. Water content was determined and the physiological quality was evaluated using germination and vigor tests (first count, seedling emergence, indices of germination speed and emergence, accelerated aging test with traditional method and with NaCl saturated solution at 41ºC and 45ºC for 24, 48, 72 hours and controlled deterioration with 20% and 24% water content for 24, 48 and 72 hours at 45ºC) in seven lots of lentil seeds cv Silvina. The use of traditional accelerated aging test and the NaCl saturated solution method at 41ºC for 48 hours were efficient to classify lentil seeds’ lots. The combination of 20% and 24% water for 48 hours exposure and of 20% water for 72 hours exposure were efficient to classify the lentil seed lots by the controlled deterioration test. 

Electrical conductivity of coffee seeds in function of the number of seeds and imbibing period / Condutividade elétrica de sementes de café em função do número de sementes e período de embebição

Coffee farming is one of the most expressive agricultural activities in Brazil. Coffee is a perennial crop with recalcitrant seeds, therefore, seed germination is irregular and lengthy. A fast evaluation of the quality coffee seeds is of an extreme importance. Thus, the objective of this work was to evaluate electrical conductivity of coffee seeds in function of the number of seeds and the imbibing period. To perform the experiments coffee seeds from four cultivars were used: IPR98, IPR100, IPR105 and IPR106. In the initial characterization the water content, the first and the last counting of the germination test and the accelerated aging of the seeds were determined. To determine seed vigor in a fast and precisely manner, the bulk electrical conductivity test was used, using replicates with 25 and 50 seeds at a temperature of 25 oC for the evaluation periods of 2, 4, 6, 8, 12 and 24 hours. A completely random design was used for the experiments. The electrical conductivity test is efficient to evaluate coffee seed vigor. Cultivar IPR98 showed more deteriorated seeds. The test performed with 25 seeds showed differences between cultivars with 24 hours of imbibing period. Using 50 seeds it is possible to evaluate the physiological quality of the cultivars starting at 4 hours of imbibing period. 

Aspectos fisiológicos e bioquímicos da germinação de sementes de alface em diferentes temperaturas

O objetivo deste trabalho foi avaliar os padrões eletroforéticos das proteínas resistentes ao calor e a atividade da enzima endo‑β‑mananase durante a germinação de sementes de alface, em alta temperatura. Sementes de oito cultivares de alface foram submetidas aos testes de germinação, primeira contagem e emergência em duas temperaturas, 20 e 35ºC. Foram calculados o índice de velocidade de germinação (IVG) e o índice de velocidade de emergência (IVE). Avaliou-se, também, a expressão das proteínas resistentes ao calor e da enzima endo‑β‑mananase, para todos os tratamentos. Utilizou-se o delineamento experimental inteiramente casualizado, em arranjo fatorial 2x8, com duas temperaturas e oito cultivares. A maior germinação é observada a 35oC na cultivar Everglades, considerada termotolerante. Os padrões de proteínas resistentes ao calor em sementes de alface apresentam bandas específicas na cultivar Everglades, a 35ºC. A atividade da enzima endo‑β‑mananase é maior na cultivar Everglades, nessa temperatura. Essa cultivar tem potencial para utilização em programas de melhoramento de alface com vistas à tolerância a altas temperaturas durante a germinação.The objective of this work was to evaluate the electrophoretic patterns of heat‑tolerant proteins and the activity of the endo‑β‑mannanase enzyme during lettuce seed germination, at high temperature. Seeds of eight lettuce cultivars were subjected to germination, first count, and emergence tests at two temperatures, 20 and 35°C. The index of germination speed (IVG) and the emergence rate index (IVE) were calculated. The expression of heat‑tolerant proteins and of the endo‑β‑mannanase enzyme was also evaluated for all treatments. The experimental design was completely randomized, in a 2x8 factorial arrangement, with two temperatures and eight cultivars. The highest germination is observed at 35°C in the Everglades cultivar, considered thermotolerant. The patterns of heat‑tolerant proteins in lettuce seeds present specific bands in the Everglades cultivar, at 35ºC. The activity of the endo‑β‑mannanase enzyme is higher in the Everglades cultivar, at this temperature. This cultivar has potential for use in lettuce breeding programs aiming for tolerance to high temperatures during germination

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Germinação e vigor de sementes de girassol Helianthus annuus ao longo do armazenamento climatizado

Trabalho de Conclusão de Curso (Graduação)A cultura do girassol é uma das mais versáteis entre as existentes. A semente de girassol deve ter, além de alto poder germinativo, também elevado vigor para proporcionar urna rápida e uniforme germinação e emergência de plântulas, sob condições edafoclimáticas extrínsecas, como umidade, temperatura e aeração. O conhecimento prévio do potencial de armazenamento de um lote de semente é muito importante para a indústria sementeira. Este trabalho teve como objetivo avaliar o desempenho das sementes de girassol armazenadas em condição de ambiente climatizado (câmara fria) por diferentes períodos de armazenamento. As sementes foram armazenadas por 300 dias, em condições climatizadas, no laboratório de sementes da Universidade Federal de Uberlândia. Os tratamentos foram constituídos por amostras de dois híbridos comerciais (H-250 e H-251), com dois níveis de vigor, constituindo um fatorial 2x2. O delineamento experimental foi o de blocos casualizados com parcelas subdivididas no tempo e com três repetições. A germinação, a classificação do vigor, a emergência em areia, o grau de umidade, o peso de mil sementes e o crescimento de plântulas das sementes foram avaliadas no início, aos 120 e aos 300 dias de armazenamento. Concluiu-se que o grau de umidade das sementes de girassol variou no decorrer do armazenamento em função do híbrido juntamente com o grau de vigor das sementes. O peso de mil sementes sofreu alterações durante a armazenagem em função dos híbridos estudos e dos graus de vigor das sementes. A germinação e a emergência em areia reduziram significativamente com o tempo de armazenamento. Independente do híbrido avaliado e do grau de vigor das sementes o crescimento do sistema radicular reduziu linearmente com o tempo de armazenamento. O mesmo não ocorreu com a parte aérea, que após 159, para o H-250, e após 169, para o H-251, dias de armazenamento retomou crescimento significativo

Physiological, isozyme changes and image analysis of popcorn seeds submitted to low temperatures

Abstract: This present study aimed to assess seed quality of popcorn seedlings subjected to low temperatures by examining their physiological changes, enzymes, and images. We used a completely randomized design with four replications in a factorial arrangement with four hybrids (P618, AP6002, AP8202, AP8203) and five temperatures (10, 13, 16, 19 and 25 °C). Their physiological quality was assessed through radicle protrusion, germination, dry mass of seedlings and emergence. We have assessed the images of seedlings through their hypocotyl and root lengths; and through rates of automatic force, uniformity and growth, provided by Groundeye. The isozyme expressions were determined for the catalase (CAT - IUBMB: EC 1.11.1.6), alcohol dehydrogenase (ADH - IUBMB: EC 1.1.1.1), malate dehydrogenase (MDH - IUBMB: EC: 1.1.1.37) and α-amylase (α-AMY - IUBMB: EC 3.2.1.1). Results show that low temperatures cause a negative effect on seed physiological quality in enzyme expression of CAT, ADH, MDH and α-AMY and on the performance of seedlings. These alterations compromise seed quality. Hybrids AP6002 and AP8203 should be recommended for sowing at up to 16 °C. The Groundeye software was efficient in the analysis of popcorn seedlings and in for the assessment of seed quality when submitted to low temperatures

Physiological, isozyme changes and image analysis of popcorn seeds submitted to low temperatures

<div><p>Abstract: This present study aimed to assess seed quality of popcorn seedlings subjected to low temperatures by examining their physiological changes, enzymes, and images. We used a completely randomized design with four replications in a factorial arrangement with four hybrids (P618, AP6002, AP8202, AP8203) and five temperatures (10, 13, 16, 19 and 25 °C). Their physiological quality was assessed through radicle protrusion, germination, dry mass of seedlings and emergence. We have assessed the images of seedlings through their hypocotyl and root lengths; and through rates of automatic force, uniformity and growth, provided by Groundeye. The isozyme expressions were determined for the catalase (CAT - IUBMB: EC 1.11.1.6), alcohol dehydrogenase (ADH - IUBMB: EC 1.1.1.1), malate dehydrogenase (MDH - IUBMB: EC: 1.1.1.37) and α-amylase (α-AMY - IUBMB: EC 3.2.1.1). Results show that low temperatures cause a negative effect on seed physiological quality in enzyme expression of CAT, ADH, MDH and α-AMY and on the performance of seedlings. These alterations compromise seed quality. Hybrids AP6002 and AP8203 should be recommended for sowing at up to 16 °C. The Groundeye software was efficient in the analysis of popcorn seedlings and in for the assessment of seed quality when submitted to low temperatures.</p></div

Physiological quality of popcorn seeds assessed by the accelerated aging test

Abstract: Despite the insufficient internal supply of popcorn kernel cultivars, the Brazilian production is continuously increasing. Therefore, searching for tests that offer fast results and reliable information on the physiological potential of the seeds is very important. The objective of this study was to assess the efficiency of the accelerated aging test, by using different times and exposure temperatures, for the evaluation of the physiological quality of popcorn seed lots. Popcorn seeds from three lots of the hybrid AP 8203 were used. For the initial characterization of the lots, the following tests were conducted: seed moisture content, first and final germination count, and field emergence. The accelerated aging test was performed in a 3x4x2 factorial scheme. After aging, the seeds were tested for moisture content, germination, and electrical conductivity. The experiment was carried out in a completely randomized design. The characteristic vigor was affected during aging, as evidenced by the increase in the amount of leachate detected by the electrical conductivity test. Seed lot 3 was most vigorous in the aging test conducted for 48 h at 45 °C. The accelerated aging test at 42 ºC for 48 h provides consistent information to differentiate seed lots of popcorn