High Physiological Quality Research Articles

Qualidade física e fisiológica de sementes de Phaseolus lunatus L.

The lima beans (Phaseolus lunatus L.) have rusticity and environment adaptability; have high levels of protein and important social aspect. The aim of this study was to evaluation the physical, physiological and morphological characteristics of the external seeds, which been collected in the Montes Claros-MG Municipal Market. The experiment has done at the Laboratory of Seed Analysis ICA/UFMG and has used three batches of four varieties, been studied: the morphology and integument coloration, moisture test, mass of thousand seeds, germination test, germination speed index, a field emergence test, emergence speed index, shoot dry mass. The experimental design has been completely randomized with factorial 4x3 (four seeds varieties vs. three different lots), with 4 repetitions, totaling 48 plots. It has found significant effects in the interaction between variety and lot about the characteristics: thousand seeds weight, germination percentage, germination speed index, emergency and initial moisture. There was variation in physical and physiological quality between studied varieties, as influenced by the environment. The varieties of lima bean called by ‘marronzinha’, ‘leite’ and ‘anduzinha’ demonstrated a high physiological quality.

Physiological Seed Quality of Melon as Affected by Fruit Ripeness

ABSTRACTIn order to obtain melon (Cucumis melo L.) seed of high physiological quality, the ideal harvesting time needs to be considered, which could be determined by fruit ripening stage. Seed viability of melon, cv. ‘Rock Cantaloup’, was evaluated based on ripening stage. A completely randomized experiment with fruit harvested at ripening stages based on color appearance and presence, or not, of epidermal reticulation, were classified as follows: I, green fruit with nonreticulated epidermis; II, green fruit with reticulated epidermis; III, yellow fruit and reticulated epidermis, and IV, 10 days after yellow fruit and reticulated epidermis. Seed were taken from fruit and evaluated based on moisture percentage, weight of 1000 seed, percentage germination and number of seed that germinated first, seedling formation, seedling growth rate, seedling length, fresh weight, dry weight, and aging speed. Physiological quality of melon seed increased as ripening advanced. Seed obtained from yellow fruit with reticulated epidermis at stage IV were best in all criteria. The best melon seed for germination and quality standards are from well-ripened fruit. However, seed from less mature fruit are still viable for use in melon cultivation.

English

The study aimed to evaluate the influence of physiological seed quality on the spatial distribution of plants in the field, as well as the effect on variability among soybean plants. Six lots of soybean cultivar CD 202, with three vigor levels (high, medium and low) and two lots on each level were used. Lots of high physiological quality showed germination of 96% and lots considered of medium vigor showed 82% of germination and vigor between 60% and 67%, whereas lots of low vigor showed 70% germination and vigor between 55% and 58%. The test was conducted in plots formed by seven 5 m long rows with spacing of 0.45 m. The sowing was performed by opening furrows by hand with the equidistant distribution of seeds using marked rulers, corrected by the germination of each seed lot. Lots of seeds of higher vigor provide greater uniformity in the distribution of plants in the field. The reduction in seed physiological quality provides increased variability among plants within populations, throughout the entire developmental period of soybean, also affecting the seed yield per plant.

Épocas de colheita e qualidade fisiológica de sementes de crambe

The objective of this study was to evaluate different harvest seasons on the seed quality of crambe, cultivar FMS Brilhante. The experiment was carried out at Experimental area of the Montes Claros State University – UNIMONTES in Janaúba-MG, on September 3, 2011. The first raceme harvest was performed 14 days after flowering, when approximately 50% of the plants showed full flowering. The other harvests were performed every six days, making a total of five harvests. Accumulation of thermal units in degrees day during time intervals was also determined. The collected racemes were taken to the Laboratory of Seed Analysis at UNIMONTES, when they remained under ambient conditions until beginning the analyses. Seeds were evaluated as for water content, germination and vigor (dry seed weight, thousand seeds weight, seedling emergence, and emergence speed). The experimental design was completely randomized, with five harvest seasons, which composed the treatments, and four replications. Crambe seeds present post-harvest dormancy. The maximum dry matter accumulation (physiological maturity) occurred 26 days after flowering. In conclusion, the best time to harvest crambe seeds, cultivar FMS Brilhante, with higher physiological quality (maximum germination and vigor) occurs within 14 to 26 days after flowering, which is a thermal sum 1111,1 to 1302, 15 degree day.

Análise de imagens no estudo morfológico e fisiológico de sementes de abóbora

A obtenção de sementes de abóbora com alta qualidade fisiológica é fundamental para colocar a produção nacional em condições de competitividade com as sementes importadas. Uma técnica que vem sendo utilizada recentemente para estudos relacionados à elucidação de vários aspectos do comportamento das sementes é a análise de imagens, incluindo as obtidas por meio do raio X. Esta técnica consiste em radiografar sementes com o objetivo de avaliar a morfologia interna e, assim, estabelecer relações com o desempenho da semente. O objetivo do presente estudo foi verificar se a técnica de raio X pode ser utilizada com sucesso na detecção de anormalidades e seus reflexos na qualidade fisiológica de sementes de abóbora. Foram utilizadas sementes de abóbora 'Brasileirinha' provenientes de frutos com diferentes estádios de maturação (30, 40, 50 e 60 dias após a antese). Em cada época, as sementes foram extraídas imediatamente após a colheita ou após o armazenamento dos frutos por 15 dias. No teste de raio X as sementes foram submetidas à intensidade de 25 kV por 40 segundos e, em seguida, foi conduzido teste de germinação sob temperatura alternada de 20-30ºC. Após quatro dias foi realizada a primeira contagem e após oito dias a última leitura, computando-se as porcentagens de plântulas normais, anormais e as sementes mortas. Após a obtenção do resultado do teste de germinação foi feita comparação desses resultados com imagens da morfologia interna de cada semente, obtidas por meio do raio X. Foi constatado que a técnica de raio X é eficiente na detecção de sementes mal formadas bem como de sementes vazias de abóbora e estas afetam negativamente sua germinação.

CO2-enriched atmosphere and supporting material impact the growth, morphophysiology and ultrastructure of in vitro Brazilian-ginseng [Pfaffia glomerata (Spreng.) Pedersen] plantlets

This study aimed to evaluate under photoautotrophic conditions the effect of CO2-enriched atmosphere (360 or 1,000 μmol CO2 mol−1 air) combined with two substrate types (agar or Florialite®) in vitro on plants of Pfaffia glomerata, an endangered medicinal species with promising applications in phytotherapy and phytomedicine. The effects of the treatments on the growth, stomatal density, Rubisco activity, carbon isotopic discrimination, metabolite accumulation, photosynthetic pigments and ultrastructural characteristics were investigated. After a 35-day cultivation period, the in vitro-growth of P. glomerata nodal segments under the different treatments resulted in plants with substantial differences in relation to their growth, photosynthetic pigments, stomatal density and leaf ultrastructural characteristics. The enrichment with CO2 coupled with a porous substrate increased the growth of P. glomerata. The stomatal density in the abaxial epidermis more than doubled in response to the high CO2 supply in both supporting types, whereas the Rubisco activity and activation state were both unresponsive to the treatments. Regardless of the CO2 supply, the plants grown in agar displayed higher carbon isotope discrimination than their counterparts grown in Florialite®. We propose that the long-term photosynthetic performance was improved using Florialite® as a growth support in combination with a high CO2 supply. No apparent signs of photosynthetic down-regulation could be found under elevated CO2 conditions. The enrichment of in vitro atmospheres with CO2 coupled with a porous substrate offers new possibilities for improving the growth and production on a commercial scale of high morphological and physiological quality Pfaffia plants.

Qualidade de sementes de pimenta jalapenho em função da maturação e tempo de permanência nos frutos

As sementes de pimenta podem apresentar baixas taxas de germinação, fato que, aliado ao desconhecimento do melhor estádio de colheita das mesmas, limita a oferta de sementes com máximo rendimento e alto vigor. Este trabalho objetivou avaliar a emergência de sementes de pimenta jalapenho extraídas de frutos colhidos aos 128 dias após o plantio, apresentando dois estádios de maturação (verde e vermelho) e submetidas ao armazenamento por 0, 7, 14, 21 e 28 dias, antes da extração das sementes. A qualidade fisiológica das sementes foi avaliada pelos testes de percentagem de emergência, primeira contagem de emergência, índice de velocidade de emergência e condutividade elétrica. Pôde-se concluir que, independentemente do estádio de maturação dos frutos, a permanência das sementes dentro deles proporcionou aumento de vigor nas sementes. A permanência das sementes por 28 dias, dentro dos frutos colhidos verdes, mostrou-se ideal para que as sementes completassem o seu desenvolvimento e adquirissem maior qualidade fisiológica.

Antioxidant activity of corn seeds after thermal stress

The aim of this research was to analyze the effect of different temperatures on physiological quality and relate the responses with the antioxidant activity of three lots of corn seeds. The seeds from three lots were exposed for 24h at temperatures of 15, 25, 35 and 40°C and then evaluated for percentage, speed index and first germination count, as well as early growth and activity of antioxidant enzymes in the seedlings. The experimental design was completely randomized with four replications, with subsequent polynomial regression analysis. The results showed that the seeds from the three lots of corn exposed to temperatures of 15 and 40°C, were of better high physiological quality (vigor), which explains the low activity of enzymes of the antioxidant defense system in these same temperatures. The antioxidant defense system is related to the physiological quality of corn seeds exposed to thermal stress.

Maturation of Eugenia pyriformis seeds under different hydric and thermal conditions

This study aims to analyze the maturation and dispersal of Eugenia pyriformis Cambess. seeds produced in different years, and the influence of variation in thermal and hydric environment on seed physical and physiological characteristics at dispersal. Fruits at different developmental stages were harvested in the city of São Paulo between 2003 and 2010, as well as in the cities of Campinas and Lavras, in 2009 and 2010 and analyzed for size and color. The seeds were extracted from the fruits and their dry mass, water content, germination and vigor were assessed. Results showed that seed maturation is unsynchronized to the maturation of the fruit, taking 45 days on average (430 growing degree-days), longer in rainy times or lower temperatures. Seeds with higher physiological quality were produced in rainy years and when the temperature range was larger. We concluded therefore that hydric and thermal environmental variations during development influence the maturation of Eugenia pyriformis seeds and are able to determine the formation cycle and the final seed quality.

Physiological quality of soybean seeds of cultivars submitted to harvesting delay and its association with seedling emergence in the field

With the aim of studying the relationship between the physiological quality of soybean seeds submitted to three harvest times and seedling emergence in the field, seeds of cultivars UFV-16, Splendor, Vencedora, Confiança, UFV-18, UFV-TN 105, Garantia and Celeste were harvested at stages R8, R8+15 and R8+30 days. The following tests were performed: accelerated aging, electrical conductivity, emergence in sand, emergence speed index and seedling emergence in the field. Germination and vigor were reduced in seeds harvested at 30 days after stage R8 in all the tests, except for the accelerated aging test, which showed a decline in vigor seeds harvested with a delay of 15 days. Seeds of cultivars UFV-16, Confiança and Garantia showed lower physiological quality in most tests, while the seeds of cultivar Celeste had higher physiological quality than the others. There was similarity between the test results of seed quality and seedling emergence in the field.

Viability of Inga vera Willd. subsp. affinis (DC.) T. D. Penn. embryos according to the maturation stage, fungal incidence, chemical treatment and storage

The main strategies for conserving Inga vera seeds during storage consist of their partial dehydration and low temperatures. However, such storage conditions can lead to further deterioration of the seed, either from its own metabolism or the development of microorganisms favored by moisture. In this study, the relationship between fungi and the conservation of I. vera embryos with different levels of hydration and maturity was studied, together with the efficiency of treating with carboxin + thiram (300 mL / 100 kg of embryos) for fungus control. Embryos were collected at two stages (immature and mature) and subjected to two drying levels. A sample of embryos from each stage and drying level was treated with carboxin + thiram. Embryos were then stored at 7 or 25 °C for up to 65 days. It was found that undried, mature embryos have a higher physiological quality than the immature ones after storage at 7 °C for 65 days. The carboxin + thiram treatment is phytotoxic for dried embryos. "Field" fungi develop according to the degree of embryo deterioration, differing from the classic pattern defined for orthodox seeds.

Physiological quality of dynamically cooled and stored soybean seeds

Storage is an important step in the production of soybean seeds, mainly in tropical regions, where high temperatures can drastically reduce seed quality. The storage at cooler temperatures may be a feasible alternative to preserve seed quality during storage. The objective of this study was to evaluate the physiological quality of soybean seeds artificially cooled by a dynamic process and stored in an environment, with non controlled temperature and relativity humidity. Two seed lots of cultivars Monsoy 8757, TMG 115 RR and BRS Valiosa RR were used. After processing and during packaging the seeds were cooled to 18 ºC by a dynamic process. Seed samples were collected after 0, 60 and 120 days of storage, using the following parameters germination, accelerated aging, seedling emergence in sand, speed of emergence index, electrical conductivity, tetrazolium and seed health. Although soybean seeds artificially cooled by the dynamic method may have slightly superior performance in maintaining physiological quality during storage in non-refrigerated warehouse, for lots of high physiological quality, these advantages are not observed.

Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

A adubação nitrogenada, além de aumentar a produtividade, pode favorecer a qualidade fisiológica de sementes. O objetivo do trabalho foi avaliar o efeito de doses de adubação nitrogenada em cobertura e de diferentes formas de ureia na qualidade fisiológica de sementes de genótipos de trigo. Foram avaliadas sementes de três genótipos (BRS 208, BRS Pardela e IWT 04008) cultivados sob quatro doses de nitrogênio em cobertura (0, 40, 80 e 120 kg.ha-1), provenientes de três formas de ureia (ureia convencional, ureia com inibidor de urease e ureia protegida). A adubação nitrogenada de cobertura foi realizada durante o estádio de perfilhamento, aos 20 dias após a emergência. Avaliaram-se: o teor de nitrogênio nas sementes, massa de 1000 sementes, germinação e vigor (primeira contagem de germinação, teste de frio, emergência de plântulas no campo, massa seca de plântulas, envelhecimento acelerado e condutividade elétrica). A linhagem IWT 04008 e a cultivar BRS Pardela apresentam sementes com qualidade fisiológica superior à cultivar BRS 208. As formas de ureia e as doses de nitrogênio em cobertura não alteram a qualidade fisiológica das sementes de diferentes genótipos de trigo.

Initial Growth of Soybean Plants from Seeds of High and Low Vigor Subjected to Water Stress

This study intends to evaluate responses on the growth of soybeans plants from seeds with high and low vigor in different drought periods. Experimental design was completely randomized in factorial AXB (Factor A: variables 0, 2, 3, 4 and 5 water stress; Factor B: level of seed vigor, high and low). Evaluations of fresh matter, plant height, leaf area and dry weight of shoots, 10, 20, 30 and 40 days after emergence (DAE). Soybean plants originated from seeds with high physiological quality perform better than the plants originated from seeds of low vigor, until 40 DAE. Water stress reduces the initial growth of soybean plants originated from seeds of both high and low force, until 40 DAE. Soybean seeds of high vigor generate plants with higher growth rate of the culture until 30 DAE, besides generating plants with greater capacity for growth after returning water stress.

Relationship between fruit maturation stage and physiological quality of physic nut (Jatropha curcas L.) seeds

The physic nut (Jatropha curcas L.) has great potential for use in biodiesel production due to the high oil content of its seeds. Production of high quality seeds depends upon the appropriate time of harvest. A field experiment was carried out to monitor the maturation process of physic nut seeds and to establish the ideal harvest time of the seeds based on external fruit color. Fruits were collected at different maturation stages based on the external color: green, yellow-green, yellow, yellow-brown and brown. Seeds were extracted manually and, after natural drying, were submitted to the following tests and determinations: moisture content and dry matter, germination, first count seedling emergence, seedling growth, accelerated aging, electrical conductivity, the weight of thousand seeds and oil content. A randomized design was used with four replications. Data were subjected to analysis of variance and, for each test, treatment means were compared by Tukey test at 5% probability. Physic nut seeds with high physiological quality are obtained from yellow and yellow-brown fruits. Seeds from green fruits have lower physiological quality, dry matter and oil content than the other maturation stages. The seeds obtained from brown fruits have a high germination potential, but have low vigor in relation to yellow and yellow-brown stages.

Detection of adventitious presence of genetically modified seeds in lots of non transgenic soybean

The difficulty on identifying, lack of segregation systems and absence of suitable standards for coexistence of non trangenic and transgenic soybean are contributing for contaminations that occur during productive system. The objective of this study was to evaluate the efficiency of two methods for detecting mixtures of seeds genetically modified (GM) into samples of non-GM soybean, in a way that seed lots can be assessed within the standards established by seed legislation. Two sizes of soybean samples (200 and 400 seeds), cv. BRSMG 810C (non-GM) and BRSMG 850GRR (GM), were assessed with four contamination levels (addition of GM seeds, for obtaining 0.0%, 0.5%, 1.0%, and 1.5% contamination), and two detection methods: immunoassay of lateral flux (ILF) and bioassay (pre-imbibition into 0.6% herbicide solution; 25 ºC; 16 h). The bioassay is efficient in detecting presence of GM seeds in seed samples of non-GM soybean, even for contamination lower than 1.0%, provided that seeds have high physiological quality. The ILF was positive, detecting the presence of target protein in contaminated samples, indicating test effectiveness. There was significant correlation between the two detection methods (r = 0.82; p < 0.0001). Sample size did not influence efficiency of the two methods in detecting presence of GM seeds.

Sementes de soja produzidas em épocas de safrinha na região oeste do Estado do Paraná

The soybean culture in out season as a practice that consolidates in terms of an option between harvests, could also serve to the production of soybean seeds. The present work was carried out with the objective of evaluating the effect of sowing in out season, on physiological and sanitary quality of seeds of three soybeans cultivars, in west of Paraná state. For such way were conducted four assays in the year of 2005, arranged in a completely randomized block design, with each assay sown in different dates (01/15, 01/30, 02/15 and 03/15). The studied cultivars were CD 202, CD 215 and CD 216. The seeds were evaluated by germination and vigor tests (first counting and accelerated aging) and of health. The seeds produced in “out season” in the year of 2005, to the environmental conditions of the west of Paraná state were not favorable to the attainment of high physiological quality seeds

Qualidade fisiológica da semente e desempenho de plantas isoladas em soja

O presente trabalho teve como objetivo avaliar o efeito da qualidade fisiológica de sementes no rendimento de grãos em plantas isoladas de soja. O trabalho foi desenvolvido na Faculdade de Agronomia Eliseu Maciel (FAEM/UFPel) utilizando a cultivar de soja Mercedez. Os tratamentos constaram de dois níveis de qualidade fisiológica, alta e baixa. O delineamento experimental foi de blocos ao acaso com 11 repetições. Os níveis de qualidade fisiológica foram obtidos a partir de um lote de sementes com 90% de germinação e 69% de vigor, utilizando como critério o período de emergência, sendo que as plântulas emergidas até o 6º dia após a semeadura foram consideradas provenientes de sementes de alta qualidade fisiológica e até o 9º e 10º dias, de baixa qualidade. Na implantação do experimento a campo semeou-se 06 sementes por cova e após emergência, realizou-se o desbaste mantendo uma planta por cova de acordo com o tratamento (alta ou baixa qualidade fisiológica). Para avaliar o efeito da qualidade fisiológica sobre o desenvolvimento individual e evitar a competição entre plantas utilizou-se espaçamento de 0,50m nas entrelinhas e entre plantas na linha. O número de ramificações por planta e o peso de 1000 sementes, não foram afetados pelo nível de qualidade fisiológica das sementes. As plantas oriundas de sementes de alta qualidade fisiológica apresentam maior altura de plantas, diâmetro de caule e rendimento de grãos 25% superior.

Morfologia de sementes e do desenvolvimento pós-seminal de espécies de Bromeliaceae

O estudo teve como objetivos caracterizar as sementes, fornecendo informações sobre o tipo e o tempo médio de germinação e de formação de plântulas, além de descrever a morfologia do desenvolvimento pós-seminal de seis espécies de Bromeliaceae. Os resultados mostram germinação do tipo epígea e plântulas criptocotiledonares para todas as espécies. As porcentagens máximas de germinação obtidas, acima de 80%, indicam alta qualidade fisiológica das sementes. O tempo médio de germinação e de formação de plântulas foi de 4-15 e 8-18 dias, respectivamente. As sementes são filiformes a elípticas, lisas ou com apêndices plumosos. Os caracteres morfológicos mais relevantes para a diferenciação entre gêneros e subfamílias de Bromeliaceae referem-se à forma e ao tipo de apêndices das sementes, e na forma e tamanho da bainha cotiledonar, hipocótilo e raiz primária das plântulas, subsidiando estudos taxonômicos, ecológicos e na área de tecnologia de sementes.

Artificial Regeneration of Major Oak (Quercus) Species in the Eastern United States—A Review of the Literature

Abstract Although natural regeneration is often the best method for establishing new oak (Quercus spp.) stands, there are increasingly more situations in which high potential for oak regeneration failure dictates the use of artificial regeneration including direct seeding and planting seedlings. Additionally, afforestation planting programs frequently incorporate oak species. Artificial regeneration of oak stands is challenging for numerous reasons. In this article we synthesize the current state of knowledge regarding growing and planting the major oak species in the eastern United States, point out critical research gaps, and provide some general growing, planting, and stand tending guidelines and recommendations. Adequate site preparation, careful planting of healthy, genetically adapted seed or seedlings of high morphological and physiological quality, and subsequent control of competing vegetation and browse damage are necessary actions to assure regeneration success. Oak seedling survival in the early years after planting or seeding is a poor indicator of regeneration success. Successful regeneration may be defined as having a desired proportion of the oak planting stock reach dominant/codominant status in the stand. The costs of all activities required to produce a successful oak tree in the future stand should be considered in economic comparison of alternative prescriptions for oak regeneration.