-The objective of this experiment was to evaluate responses of soybean cultivars seeds (with different levels of lignin) considering harvest postponement under the incidence of water and the effect of storage. The experiment was conducted in Iraí de Minas, Brazil using a randomized block design with three replications under a 5 x 3 x 3 factorial arrangement, with five soybean cultivars (NK 7059 RR, SYN 1163 RR, SYN 9070 RR, AS 7307 RR and SYN 1283 RR), three harvesting periods (R8, R8 + one rain simulation in the pre-harvesting period and R8 + two simulations in the pre-harvesting period) under three storage times (0, 90 and 180 days). Seeds were evaluated for their chemical composition (lignin contents), the percentage of moisture damage using the tetrazolium test and physiological quality (germination, accelerated aging, conductivity test, seedling emergence and emergence index). Cultivar AS 7307 RR had the highest lignin content in the integument, the lowest percentage of damage by moisture and the highest physiological quality. Cultivars NK 7059 RR and SYN 1163 RR had the lowest lignin contents in the integument and the highest moisture damage. Electrical conductivity increased after storing all cultivars.Index terms: Glycine max, lignin, storage.Qualidade fisiológica de sementes de soja submetidas à chuva artificial na pré-colheita RESUMO -Objetivou-se com este trabalho avaliar o desempenho de sementes de cultivares de soja com diferentes teores de lignina considerando o retardamento da colheita sob incidência artificial de chuva, e ao longo do armazenamento. O ensaio foi conduzido em Iraí de Minas, MG, em blocos casualizados com três repetições e esquema fatorial 5 x 3 x 3, sendo cinco cultivares de soja (NK 7059 RR, SYN 1163 RR, SYN 9070 RR, AS 7307 RR e SYN 1283 RR), três épocas de colheita (R8, R8 + uma simulação de chuva na pré-colheita e R8 + duas simulações de chuva na pré-colheita), e três épocas de armazenamento (0, 90 e 180 dias). As sementes foram avaliadas quanto à composição química (teor de lignina), porcentagem de danos por umidade usando o teste de tetrazólio, e a qualidade fisiológica (germinação, teste de envelhecimento, condutividade elétrica, emergência, índice de emergência). A cultivar AS 7307 RR apresentou maior teor de lignina no tegumento, menor porcentagem de danos por umidade e melhor qualidade fisiológica. As cultivares NK 7059 RR e SYN 1163 RR apresentam menores teores de lignina no tegumento e maiores danos por umidade. Os valores de condutividade elétrica aumentam com o armazenamento para todas as cultivares.Termos para indexação: Glycine max, lignina, armazenamento.

Resumo -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 35 o C. 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 35 o C 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.Termos para indexação: Lactuca sativa, endo-β-mananase, proteínas tolerantes ao calor, termoinibição. Physiological and biochemical aspects of lettuce seed germination at different temperaturesAbstract -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.

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ABSTRACT. The aim of this study was to characterize maize lines tolerant to cold temperatures during the germination process. Seeds from lines with different levels of tolerance to low temperatures were used; 3 lines were classified as tolerant and 3 as susceptible to low germination temperatures. A field was set up to multiply seeds from selected lines. After the seeds were harvested and classified, we conducted physiological tests and analyzed fatty acid content of palmitic, stearic, oleic, linoleic, linolenic, and eicosenoic acids. In proteomic analysis, the expression of heat-resistant proteins, including catalase, peroxidase, esterase, superoxide dismutase, and α-amylase, were evaluated. Transcript analysis was used to measure the expression of the genes AOX1, AOX2, ZmMPK-17, and ZmAN-13. The material showing the highest susceptibility to low germination temperatures contained high saturated fatty acid content. Expression of α-amylase in seeds soaked for 72 h at a temperature of 10°C was lower than expression of α-amylase when soaked at 25°C for the same amount of time. We observed variation in the expression of heat-resistant proteins Gene expression related to temperature tolerance in maize in seeds of the lines evaluated. The genes AOX and Zm-AN13 were promising for use in identifying maize materials that are tolerant to low germination temperatures.

The use of an appropriate method that accurately expresses physiological seed quality and minimizes possible phytotoxicity by chemical products in laboratory testing with soybean seeds is relevant. The objective of this work was to evaluate the influence and infer the method adequacy for the representative evaluation of physiological quality of soybean seeds treated with phytosanitary products. Two experiments were carried out in a completely randomized design, with trial 1 in a 9×5 factorial scheme involving nine seed treatments, including fungicides and insecticides, and solutions with five osmotic potentials (0, -0.25, -0.5, -0.75 and -1.0 MPa) for wetting a paper substrate in a germination experiment, with evaluation of the normal seedlings at five and eight days after sowing. The second experiment consisted of a 9×7 factorial, with nine seed treatments and seven methods for germination evaluation at 5 days (between paper - BP, between sand - BS, between paper with water restriction - BPWR, between paper with preconditioning - BPC, sand between paper - SBP and vermiculite between paper - VBP). Treatments with insecticides affect seedling germination and evaluation, with greater phytotoxicity in relation to fungicides. Methods with readily available water led to greater phytotoxicity than methods with low water availability. For soybean germination evaluation of seeds treated with phytosanitary products, the BPC, SBP and VBP methods were optimal.

Early characterization of maize (Zea mays L.) genotypes, as well as the study of the genetic control of traits associated with water deficit tolerance, can provide information to guide breeders in the selection of cultivars adapted to drought environments. The aim of this study was to estimate heterosis and combining ability of maize genotypes under water stress during seed germination and seedling emergence. Four inbred lines previously characterized as water stress tolerant were crossed with four nontolerant lines in partial diallel scheme to obtain 16 hybrids and 16 reciprocals. Seeds were germinated in trays with sand in two environments, with and without water stress, with field capacity adjusted to 10 and 70% of humidity. The traits evaluated were seedling emergence, emergence speed index, shoot length, root length, number of seminal roots, and shoot and root dry weights. The heterosis effect, general combining ability, specific combining ability, and reciprocal effects were estimated for each trait using a partial diallel mixed model. The nonadditive effects were more important, and heterosis was observed in all cases, more expressively for root traits. The reciprocal effects were significant, highlighting the importance of the correct choice of the female parent to obtain maize hybrids tolerant to water stress.

-The present study aimed to evaluate effects of different storage conditions on the castor bean seed cultivar IAC-226 quality, stored for 12 months. For this purpose, seeds were stored in different environment and packaging conditions: in a cold chamber and conventional storage, using multiwall Kraft paper and in no vacuum and vacuum plastic packages at 1 atm; as well as under cryopreservation storage (-196 °C). Seed quality was evaluated before and after 4, 8 and 12 months of storage by germination tests, first count of germination, emergence percentage, emergence speed index and determination of changes in catalase (CAT) and superoxide dismutase (SOD) enzyme systems. Cryopreservation (-196 °C) is efficient in maintaining the physiological quality of castor bean cultivar IAC-226 for 12 months. The enzyme catalase stands out as a marker of castor seed deterioration during storage.Index terms: Ricinus communis L. storage, cryopreservation, vacuum.Aspectos bioquímicos e fisiológicos da deterioração de sementes de mamona armazenadas em diferentes embalagens e temperaturas RESUMO -Objetivou-se avaliar os efeitos de diferentes condições de armazenamento sobre a qualidade de sementes de mamona cultivar IAC-226, armazenadas por um período de 12 meses. Para isso, as sementes foram armazenadas em diferentes ambientes e tipos de embalagens: em câmara fria e armazém convencional, utilizando embalagens papel Kraft multifoliado e plástico com e sem acondicionamento a vácuo a 1 atm; e também armazenamento sob criopreservação (-196 °C). A qualidade das sementes foi avaliada antes e após 4, 8 e 12 meses de armazenamento pelos testes de geminação, primeira contagem de germinação, porcentagem de emergência, índice de velocidade de emergência e pela determinação das alterações nos sistemas enzimáticos catalase (CAT) e superóxido dismutase (SOD). A criopreservação (-196 °C) é eficiente na manutenção da qualidade fisiológica de sementes de mamona cultivar IAC-226 por 12 meses. A enzima catalase se destaca como um marcador da deterioração de sementes de mamona durante o armazenamento.Termos para indexação: Ricinus communis L., isoenzimas, criopreservação, armazenamento.1

ABSTRACT. Studies evaluating the internal morphology and seed quality of native species are essential for successful conservation programs. Our aim was to verify the efficiency of X-ray imagery in evaluating cashew-tree-of-the-cerrado (Anacardium othonianum Rizz.) achene viability after desiccation. The achenes were collected at 12% water content (w.b.) and dried in silica gel until they reached 10, 8, 6, and 4% (w.b.). The fruit morphology and the quality of the seeds were evaluated by X-ray test together with vigor, electrical conductivity and emergence tests. Achenes with different water contents were exposed to an Xray machine at 18 kV for 11 s and were thereafter submitted to emergence tests. The images were analyzed, and the achenes were classified based on internal morphology as completely full, malformed, or empty. These results were compared to those from the emergence tests. The statistical design was a complete randomized factorial (5 x 3). Desiccation to 4% (w.b.) did not damage or modify the internal structures. Xray was efficient in evaluating the internal morphology and detecting achene quality, making it possible to remove empty and abnormal fruit and form vigorous seed lots, reducing the cost of storage and bedding plant production for this native species.Keywords: X-Ray, fruit tree, cerrado, desiccation, internal morphology.Análise de imagens radiográficas em aquênios de Anacardium othonianum Rizz (anacardiaceae) submetidos à secagem RESUMO. Estudos referentes à avaliação da morfologia interna e da qualidade de sementes de espécies nativas são de fundamental importância para o sucesso dos programas de conservação. Objetivou-se com este estudo verificar a eficiência do teste com raios X na avaliação da viabilidade de aquênios de caju-deárvore-do-cerrado (Anacardium othonianum Rizz.) submetidos à secagem. Para tal, aquênios de A. othonianum Rizz foram coletados com 12% (b.u.) e submetidos à secagem em sílica gel até a obtenção dos teores de água de 10, 8, 6 e 4% (b.u.). Os frutos foram avaliados quanto à morfologia interna e qualidade física pelo teste de raios X, e o vigor das sementes pelos testes de germinação, condutividade elétrica e emergência de plântulas. Para a obtenção das imagens radiográficas, aquênios com diferentes teores de água foram expostos à radiação em um aparelho de raios X digital "Faxitron HP", MX-20 à intensidade de 18 kV por 11 segundos, e posteriormente foram submetidos ao teste de emergência. As imagens radiográficas foram analisadas e os aquênios classificados de acordo com a morfologia interna em três categorias: Cheios, mal formados e vazios. O delineamento estatístico utilizado foi o inteiramente casualizado em esquema fatorial (5 x 3). A secagem dos frutos até 4% (b.u.) não danificou ou alterou as estruturas internas dos aquênios. O teste de raios X é eficiente na avaliação da morfologia interna e na detecção da qualidade de aquênios de A. othonianum Rizz, possibilitando a separação de aquênios vazios ou com anormalidades embrionárias e permite a formação de lotes ...