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

Produção de mudas de tomateiro em função de diferentes formas de propagação e substratos

Uma alternativa para diminuir o custo de produção do tomateiro é o uso de propagação assexuada para a obtenção de mudas, além disso, a utilização de um substrato adequado pode promover um melhor enraizamento e desenvolvimento das estacas. Assim, objetivou-se com este trabalho avaliar o efeito de diferentes formas de propagação e substratos na produção de mudas de tomateiro. Realizou-se o experimento em casa de vegetação com estacas coletadas a partir de brotos laterais de plantas matrizes sadias, padronizadas em dois tamanhos e sementes híbridas de tomateiro. As estacas e sementes foram cultivadas em dois substratos comerciais, em delineamento experimental inteiramente casualizado, em esquema fatorial 3x2 (propagação x substratos), quatro repetições, totalizando 24 parcelas. Houve interação entre as formas de propagação e os tipos de substratos para as seguintes características: massa fresca das raízes, massa fresca da parte aérea, comprimento da raiz principal, comprimento final da parte aérea, massa seca da raiz, massa seca da parte aérea, massa fresca total e massa seca total. O enraizamento foi afetado pelo substrato, enquanto o comprimento da raiz principal pelas formas de propagação. As estacas de 11 cm de comprimento se destacaram, tornando a propagação vegetativa do tomateiro viável. A utilização do substrato de fibra de coco promoveu melhor desenvolvimento radicular

Production of tomato seedlings for different substrates and means of propagation = Produção de mudas de tomateiro em função de diferentes formas de propagação e substratos

In reducing the cost of production, one alternative is the use of asexual propagation when obtaining tomato seedlings. Use of the appropriate substrate can also result in better rooting and development of the cuttings. The aim of this experiment therefore, was to evaluate the effect of different substrates and means of propagation in the production of tomato seedlings. The experiment was carried out in a greenhouse with cuttings collected from the side shoots of healthy mother plants, sorted into two sizes and hybrid tomato seeds. The seeds and cuttings were grown in two commercial substrates. The experimental design was completely randomised in a 3x2 factorial scheme (propagation x substrate), with four replications, giving a total of 24 lots. There was interaction between the means of propagation and types of substrate for the following characteristics: root fresh weight, shoot fresh weight, length of main root, final length of shoots, root dry weight, shoot dry weight, total fresh weight and total dry weight. Rooting was affected by the substrate, and main root length by the means of propagation. The cuttings of 11 cm in length stood out for making the vegetative propagation of the tomato viable. Using coconut fibre as a substrate promoted better root development = Uma alternativa para diminuir o custo de produção do tomateiro é o uso de propagação assexuada para a obtenção de mudas, além disso, a utilização de um substrato adequado pode promover um melhor enraizamento e desenvolvimento das estacas. Assim, objetivou-se com este trabalho avaliar o efeito de diferentes formas de propagação e substratos na produção de mudas de tomateiro. Realizou-se o experimento em casa de vegetação com estacas coletadas a partir de brotos laterais de plantas matrizes sadias, padronizadas em dois tamanhos e sementes híbridas de tomateiro. As estacas e sementes foram cultivadas em dois substratos comerciais, em delineamento experimental inteiramente casualizado, em esquema fatorial 3x2 (propagação x substratos), quatro repetições, totalizando 24 parcelas. Houve interação entre as formas de propagação e os tipos de substratos para as seguintes características: massa fresca das raízes, massa fresca da parte aérea, comprimento da raiz principal, comprimento final da parte aérea, massa seca da raiz, massa seca da parte aérea, massa fresca total e massa seca total. O enraizamento foi afetado pelo substrato, enquanto o comprimento da raiz principal pelas formas de propagação. As estacas de 11 cm de comprimento se destacaram, tornando a propagação vegetativa do tomateiro viável. A utilização do substrato de fibra de coco promoveu melhor desenvolvimento radicula

PRODUCTIVE POTENTIAL OF THE CHERRY TOMATO GENOTYPE GROUP BEFORE INFECTION BY Alternaria tomatophila

Early blight (caused by Alternaria tomatophila ) is a major disease of tomato with no resistant cultivars. Thus, it is necessary to identify sources of resistance and productive genotypes for the development of new cultivars. Therefore, this study aimed to evaluate the productive potential of cherry tomato genotypes grown in the summer / fall, the severity of early blight on leaves and the incidence of disease in fruits. The treatments consisted of Carolina tomato genotypes, Cereja Vermelho, CH 152 and CLN1561A. The experimental design consisted of randomized blocks with six replications, and the experimental plot had 16 plants. The following characteristics were evaluated: area under the disease progress curve (AUDPC), average number of microinjuries on the fruits (MF), average number of fruits per bunch (NFC), average number of bunches per plant (NCP), average number of fruits per plant (NFP), average yield, number of fruits with incidence of early blight per plant (NFI) and the severity of early blight in leaves (%). The cherry tomato genotype CH152 showed tolerance to early blight with a smaller area under the disease progress curve, lower severity and fruits with incidence of A. tomatophila were not observed in this genotype. The CH152 had the highest number of fruits per bunch, greater number of bunches per plant, higher number of fruits per plant and higher productivity. This line has great potential of being integrated into breeding programs

Incidência e viabilidade de sementes crioulas de milho naturalmente infestadas com fungos em pré e pós-armazenamento Incidence and viability of creole seeds of corn naturally infested with fungi in pre-and post-storage

Objetivou-se com este trabalho avaliar a qualidade sanitária e fisiológica de quatorze variedades de sementes de milho crioulas em pré e pós-armazenamento em embalagens de polietileno tereftalato (PET). Houve efeito das variedades e das épocas de avaliações sobre a incidência de fungos e germinação. Dentre a micobiota observada, Fusarium moniliforme (88%), Penicillium spp. (6,9%) e Aspergillus spp. (2,1%) tiveram a maior porcentagem de incidência. Após o armazenamento, houve decréscimo de F. moniliforme (69%) e aumento de Penicillium spp. (35%) e Aspergillus spp. (22%). A incidência desses fungos não comprometeu a qualidade fisiológica das sementes, que apresentaram elevadas porcentagens de vigor e germinação.<br>The objective of this study was to evaluate the sanitary and physiological quality of fourteen varieties of creole corn seeds in pre-and post-storage in packaging of polyethylene terephthalate (PET). Among the mycobiota observed Fusarium moniliforme (88%), Penicillium spp. (6,9%) and Aspergillus spp. (2,1%) had the highest incidence. After storage there was a slight decrease in the percentage of F. moniliforme (69%) and a increase of Penicillium spp. (35%) and Aspergillus spp. (22%). The incidence of these fungi did not compromise the physiological quality of seeds that showed high percentages of vigor and germination