First Count Of Germination Research Articles

Cytogenetic analysis of wheat seeds submitted to artificial aging stress

Several studies have been developed to understand the physiology of seed deterioration, however, the initial steps of the deterioration process are not completely clear. Seed vigor and viability losses are also associated with genetic material damage. This study was carried out to detect cytogenetic and physiological alterations occurring during the deterioration process of wheat seeds, due to artificial aging stress. Two cultivars, Ônix and Fundacep Campo Real, were submitted to six different treatments: control (T1), 24 (T2), 48 (T3), 72 (T4), 96 (T5) and 120 (T6) hours under artificial aging conditions: 42 °C and 100% relative humidity. Germination and vigor tests (First Count of Germination, Electrical Conductivity, Seedling Emergence in the Field and Emergence Speed Index) were performed. Cytogenetic evaluations were performed through smear technique for root tips, stained with 2% acetic orcein. Total number of cells under division and mitotic index (MI) were determined. According to results, vigor and mitotic index were affected due to deterioration process induced by artificial aging stress. A reduced number of dividing cells were observed in seeds submitted to prolonged period of aging. Chromosomal abnormalities in mitotic cells of aged seeds were detected with the occurrence of micronuclei, chromosome breaks and bridges.

Fertilidade do solo na qualidade fisiológica de sementes de soja

This study aimed to determine the variability of soil fertility in the fields of seed production and its effect on seed physiological quality of soybean seeds by precision agriculture tools. A sampling grid of 1 point per hectare was established, where soil and seed samples were collected. In soil samples were determined the concentrations of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), organic matter (%), clay contents (%), bases saturation (%), aluminum saturation (%), pH and cation exchange capacity (CEC). Seed quality was evaluated by germination test, first count of germination, accelerated aging and seedling emergence. From the obtained data, interpolation maps were created, besides correlation analysis among the factors studied. Soil properties evaluated, as well as the seed physiological quality showed spatial variability at different concentrations. Furthermore, the increase of Ca and effective CEC positively affect the germination of soybean seeds, while Al saturation of the soil adversely affects the soybean seeds vigor.

Envelhecimento acelerado na avaliação da qualidade fisiológica de sementes de Ricinus communis L.

The increase in the demand for seeds of castor bean in Brazil comes unchaining a great interest in tests that make possible the differentiation of lots of superior quality. Amongst the available tests, the accelerated aging is one of the most studied and recommended one for seeds of diverse crops. We used six seed lots IAC-226, and the quality assessed by the initial water content, germination, first counting of germination, plantlets emergence and emergence speed index. The seeds were submitted to accelerated aging test, adapted to temperatures 40 and 42 °C for periods of 48 and 60 hours in a completely randomized design with four repetitions. The accelerated aging was efficient for physiological potential evaluation of castor bean seeds, IAC226 cultivar, with a temperature of 42 °C for 60 hours, the most appropriate procedure for classifying lots into different vigor levels.

Crescimento de plântulas de aveia branca submetidas ao estresse salino

The cultivation of white oat in succession to irrigated rice is considered a viable alternative, mainly because of their added value and for their restorative characteristics of the soil, though their productive potential can be reduced considerably because of the soil salinization, being very important to determine salt concentration tolerated by different white oat cultivars.The objective is to evaluate, oat cultivars recommended for the state of Rio Grande do Sul under different salt concentrations in seed germination and early growth. The experimental design was completely randomized factorial 2X5, with four replications, (cultivars Barbarasul and Chiarasul, salt concentration and levels 0, 25, 50, 75 and 100 mM NaCl per liter of water). The physiological seed quality was evaluated in the laboratory by germination, first count of germination, length of shoot and root dry weight of shoot and root. Based on the results we can conclude that: germination and seedling growth of oat cultivars and Barbarasul Chiarasul are negatively affected with increasing salt concentration. In addition the response is more pronounced on the shoot than the root system. The concentration of 100 mM NaCl L-1 impossible to seed germination of both cultivars.

Crescimento de plântulas de aveia branca submetidas ao estresse salino

The cultivation of white oat in succession to irrigated rice is considered a viable alternative, mainly because of their added value and for their restorative characteristics of the soil, though their productive potential can be reduced considerably because of the soil salinization, being very important to determine salt concentration tolerated by different white oat cultivars.The objective is to evaluate, oat cultivars recommended for the state of Rio Grande do Sul under different salt concentrations in seed germination and early growth. The experimental design was completely randomized factorial 2X5, with four replications, (cultivars Barbarasul and Chiarasul, salt concentration and levels 0, 25, 50, 75 and 100 mM NaCl per liter of water). The physiological seed quality was evaluated in the laboratory by germination, first count of germination, length of shoot and root dry weight of shoot and root. Based on the results we can conclude that: germination and seedling growth of oat cultivars and Barbarasul Chiarasul are negatively affected with increasing salt concentration. In addition the response is more pronounced on the shoot than the root system. The concentration of 100 mM NaCl L-1 impossible to seed germination of both cultivars.

Produção e qualidade fisiológica de semente de feijão após aplicação do herbicida Diquat

The objective of this research was to evaluate the influence of Diquat herbicide application, at different periods, on production and physiological quality of bean seeds, cultivar: Perola. The experimental design used was a randomized block (RBD). The treatments were constituted of application of such herbicide with dosage of 400 g ai / ha in eight stages of application (83, 85, 87, 89, 91, 93 and 95 days after seeding (DAS) and without application with 97 days – witness .) The analyzed variables were moisture content (%), germination (%), first count of germination (%)velocity index of germination, seedling emergence (%), initial stand (%)velocity index of emergency, thousand seed weight (g) and production (kg ha-1). The moisture content of the bean seeds at the times of herbicide application declined, anticipating up to 14 days to harvest beans. For the first counting and germination no difference was observed between treatments. But for the IVG observed superior results at 83 DAS. For emergence percentage and EVI the values were lower at 87 and 89 DAS. On the other hand, the data obtained for the initial stand did not differ. For the thousand seed weight and production results were superior to 89 DAS and at 89 and 95 DAS, respectively. The application of Diquat desiccant in bean crop from 83 days after sowing did not affect the germination of the seeds, however, affect significantly the production of seeds.

Potássio via recobrimento de sementes de soja: efeitos na qualidade fisiológica e no rendimento

No presente trabalho, o objetivo foi avaliar a qualidade fisiológica e o rendimento de sementes de soja recobertas com diferentes fontes e concentrações de potássio. Utilizando a cultivar de soja 'CD 201', cujo delineamento experimental adotado foi inteiramente casualizado e os tratamentos constaram de um fatorial 2x5 (fontes de potássio: KCl e K2SO4 e níveis: 0, 5, 50, 500 e 5000mg L-1), totalizando dez tratamentos. As sementes foram recobertas com 2mL de solução de potássio + 2mL de Polímero (Sepiret®) + 2mL de Inoculante (Rizofix®) por quilo, totalizando 6mL kg-1 de semente. As variáveis analisadas foram primeira contagem da germinação, germinação, envelhecimento acelerado, teste de frio e comprimento da parte aérea e raiz; após a colheita, avaliou-se a qualidade fisiológica e o rendimento das sementes produzidas. O recobrimento de sementes de soja, cultivar 'CD 201', com cloreto e sulfato de potássio não influencia na germinação, mas o cloreto de potássio beneficia o desempenho das plântulas. O potássio via recobrimento de sementes com sulfato e cloreto de potássio até 5000mg L-1 de semente não interfere no seu rendimento, porém o sulfato de potássio produz sementes de melhor qualidade.

Performance of rice seeds treated with zinc, boron, and molybdenum

The objective of this study was to assess physiological quality of seeds and the initial growth of lowland rice seedlings, cv. PUITA INTA-CL, treated with a product based on Zinc, Boron and Molybdenum. The following dosages of product were used: 0 (control), 50, 100, 150 and 200 mL.100 kg-1 seed. A completely randomized experimental design was used, with 10 treatments and four replications. Physiological quality of seeds was assessed by following tests: germination; first count of germination; and length and dry phytomass of seedlings. The initial growth was assessed at 7, 14, 21, 35, and 42 days after emergence (DAE) through plant height, leaf area and dry phytomass of aerial parts and roots. It was concluded that the treatment of rice seeds with the product containing Zinc, Boron and Molybdenum up to the dosage tested of 200 mL.100 kg-1 seed does not influence germination, first count of germination, and the dry phytomass of aerial parts and roots; however, negatively influences seedling length. In addition, it also promotes greater plant height, higher leaf area, higher production of dry phytomass of seedlings, and increase on the growth rate, until 42 DAE.

Osmotic priming of rice seeds subjected to low temperatures

Aiming at verifying effects of priming on germination and emergence of seeds subjected to low temperatures, rice seeds (cv. IRGA 418) were primed into a KNO3 solution during 24, 48, and 72 h, at 20 °C; and into distilled water, for 24 h (control). Germination (G), first count of germination (FCG), and germination speed index (GSI) were the parameters assessed under temperatures of 17 °C, 20 °C and 25 °C. Besides, field emergence (FE), and emergence speed index (ESI) were also assessed under field conditions. A completely randomized design was used with treatments arranged in 4 x 3 factorial (treatments x temperatures) in all experiments. None statistically significant difference was found for seed germination within the 24 h imbibition period, under any of temperatures assessed; although after 48 and 72 h, at 17 °C, this variable has decreased. When seeds were imbibed in KNO3, during 48 and 72 h, the FCG and GSI were decreased, as compared to 24 h imbibition period, and for control treatment, at 17 °C and 25 ºC. After 24 h imbibition, the FE has not differed statistically from control treatment; as occurred for periods of 24 and 48 h imbibition for the ESI parameter. Priming in KNO3 does not cause beneficial effect on seed germination or on seedling emergence of rice.

Physiological quality of castor bean seeds originating from different racemes in the plant

The harvesting is one of the most critical phases in castor bean seed production system, once physiological quality of the seeds produced in the different types of racemes in the plant can be affected. The aim of this study was assessing physiological quality of castor bean seeds in function of position of the racemes on plant. Castor bean seeds, cv. IAC-226, harvested separately at distinct periods from primary, secondary, and tertiary racemes, or of mixture of seeds originating from the different types of racemes were used. Soon after harvest, the following determinations were performed: moisture content; 1,000 seeds weight; germination; first count of germination; seedling emergence; emergence speed index; and length and dry matter of seedlings. A completely randomized experimental design was used with four repetitions. Data were subjected to ANOVA and means were compared by Tukey test, at 5% probability. The seeds from primary racemes present higher weight and vigor as compared to seeds produced on other types of racemes. Seeds originating from secondary and tertiary racemes present post-harvest dormancy, being this event more evident on seeds originating from tertiary racemes.

Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds

We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development.

Assessment of the physiological potential of spinach seeds (Tetragonia tetragonoides (Pall.) Kuntze)

The efficiency of vigor tests in assessing the physiological potential of seeds depends on their standardization for different species. In this context, the research aimed to study specific methodologies to evaluate the vigor of spinach seeds (Tetragonia tetragonoides). For this purpose, five lots of spinach seed cv. New Zealand were submitted to germination, first count of germination, seedling emergence in the field, accelerated aging (with and without use of saturated solution of NaCl at 41and 45 ºC for 24,48 and 72 hours), controlled deterioration (18,21 and 24% seed water content adjustments for 24 hours at 45 ºC) and electrical conductivity tests with variations inwater volume (25, 50 and 75 mL), seed quantity (25 and 50) and soaking period (1, 2, 4, 8,12, 16 and 24 hours) at 25 ºC. The first count test allowed obtaining preliminary information about seed vigor, and other tests in general showed similarity with seedling emergence in the field. Thus, it was concluded that traditional accelerated aging test 24 h /41 ºC and accelerated aging test with saturated salt solution for 24 h at 41 ºC and 45 ºC, and controlled deterioration test with 21% seed water content / 24 h / 45 ºC were all efficient for evaluating the physiological potential of spinach seeds.

Phosphorus rates on yield and quality of lettuce seeds

Because of lack of information about phosphorus fertilization in lettuce from the standpoint of seed production, this study was undertaken. The work was carried out in Botucatu, São Paulo state, Brazil, from September 25, 2003 to February 19, 2004, in order to study the influence of crescents phosphorus rates on yield and quality of lettuce seeds, cultivar Verônica. The experimental design was randomized blocks with five treatments (0; 200; 400; 600 and 800 kg ha-1 of P2O5) and five replications. The following characteristics were evaluated: seed production per plant (g plant-1), number of seeds per plant and quality (percentage of germination and seed vigor). A linear increasing was observed on production and number of seeds per plant of lettuce with phosphorus rates, but these rates did not affect the seed physiological quality evaluated on weight of 1,000 seeds (average = 0.91 g), first count of germination (98%), standard germination test (99%), seed germination speed index (68.5), seedling emergence speed index (97.0) and emerged seedlings (49.3%).

Allelopathic effects of aqueous extract of Brassica napus on germination of seeds of Phaseolus vulgaris

Secondary compounds produced by plants are considered an alternative method of weed suppression but can cause negative effects on crops in succession, especially in a no-tillage system, due to the degradation of crop residues with allelopathic potential. The objective of this work was to analyze the influence of foliar aqueous extracts of Brassica napus on the germination and initial development of seedlings of Phaseolus vulgaris. The extract was prepared as a stock 10 % weight/volume solution, and diluted into treatments of relative concentrations of 100 % (i.e. 10 % w/v stock), 75 %, 50 %, 25 % and 0 % (untreated control consisting of distilled water), in a completely randomized design. The seeds of Phaseolus vulgaris were moistened with the differing concentrated extracts and kept in a germination chamber at 25 °C, with a photoperiod of 12 h for nine days. The variables evaluated were: percentage germinating, first count of germination and germination velocity index, as well the root and hypocotyl length, and fresh and dry mass of the seedlings. The aqueous leaf extracts of Brassica napus did not influence the germination of Phaseolus vulgaris seeds, but did induce the growth of abnormal seedlings by inhibition of secondary roots and reduced prominence of the primary root.

Priming and drying on the physiological quality of eggplant seeds

We evaluated the effect of the priming with polyethyleneglicol (PEG) 6000 followed or not of drying on two lots of eggplant seeds with medium and low vigor respectively. The seeds were submitted to the treatments of priming with PEG 6000 in the osmotic potentials of -0.6, -0.9 and -1.2 MPa during 48 or 96 hours of priming with and without subsequent drying. For the soaking of seeds in osmotic solutions, these were placed over three sheets of paper boxes such germitest gerbox conditioning moistened with each solution in a 3:1 ratio. The control group was represented by unprimed seeds. The priming for both lots provided higher values in relation to the vigor through the first counting of germination, seedlings and primary root length, germination and emergence rates, emergence and dry weight of seedlings when compared to the non-primed seeds. These results were not verified for germination; significant differences practically were not observed in relation to the controls. Improvements in relation to the vigour were not higher on lot 2 than those obtained on lot 1. The priming with PEG 6000 with subsequent drying increased the vigor of eggplant seeds of the cultivar Morro Grande in relation to those non-primed, however, without differences in the germination.

Potencial fisiológico de sementes de girassol influenciado pelo umedecimento artificial

O objetivo do trabalho foi avaliar a qualidade fisiológica de sementes de girassol após a hidratação pelos métodos da atmosfera úmida e substrato úmido em temperaturas de 10 e 20°C visando a elevar o teor de água das sementes a 15, 20 e 25%. A qualidade fisiológica inicial e após o umedecimento das sementes foi determinada por testes de germinação e vigor (primeira contagem da germinação, germinação a baixa temperatura, emergência e índice de velocidade de emergência de plântulas em areia, massa de matéria seca e comprimento de plântulas). O método do substrato úmido a 10°C visando a aumentar o teor de água a 15 e 20% foi favorável em sementes de elevada qualidade, embora com redução do vigor das plântulas.

Composto orgânico no potencial fisiológico de sementes de brócolis após o armazenamento

The study was carried out with the objective to evaluate the broccoli seeds (cultivar Ramoso Santana) germination and vigor from plants cultivated with different organic compost levels and after storage in dry chamber. At seed production stage, the experiment was conducted in randomized complete blocks design, with five treatments (0; 30; 60; 90 and 120 t ha-1 of Biomix® organic compost) and four replications. Soon after harvesting and after 12 and 24 months of conservation in dry chamber room (20ºC and 40% relative humidity) it was evaluated germination, following seed analisys rules, and vigor (first count of germination and germination speed index – IVG). There were no differences in germination and vigor in seeds as soon as they were harvested and after 12 month of storage. After 24 months of storage, the lesser the organic compost rates, the lesser seed germination and IVG, with respective values, without compost, of 69% and 12,3. For another hand, the highest values for germination and IVG, 82% and 16,1, respectively, were obtained with the highest rate of organic compost (120 t ha-1).

Physiological maturity of fruits and seeds of Poincianella pyramidalis (Tul.) L.P. Queiroz

The Leguminosae family is one of the most representative botanical families of the Caatinga, with 80 endemic species, highlighting the catingueira (Poincianella pyramidalis). The objective of this research work was to study the maturation process of P. pyramidalis seeds based on the physiological maturity. Five harvest of fruits and seeds were carried out, with 15 days interval each, in a period from July to September 2010. The harvests began 75 days after anthesis (d.a.a.) and lasted until 135 d.a.a. Fruits and seeds were subjected to the following assessments: size, moisture content, and dry mass of fruits and seeds; and germination and vigor of seeds (first count of germination, germination speed index, length and dry mass of seedling). Under the environmental conditions of municipality of Soledade, State of Paraiba, Northeast Brazil, the point of physiological maturity of P. pyramidalis seeds occurs at 125 d.a.a., when the maximum accumulation of dry mass is 1.993 g and moisture content is 21%. The ideal point of harvest is between 130 d.a.a and 135 d.a.a., before natural dehiscence, when the moisture content of seeds is between 13.0% and 5.0%.

Performance of lowland rice seeds coated with dolomitic limestone and aluminum silicate

The objective of this study was to evaluate the performance of seeds of two cultivars of lowland rice (Oryza sativa L.), coated with dolomitic limestone and aluminum silicate. It was used a completely randomized experimental design, with the treatments arranged in a 4 X 2 factorial scheme [4 treatments: dolomitic limestone; dolomitic limestone + aluminum silicate; aluminum silicate, at the dosages of 50 g/100 kg of seeds; and control (without the products) X 2 cultivars: IRGA424 and IRGA 422 CL], totaling eight treatments with four replications each. The variables analyzed were: fresh and dry weights of aerial biomass; plant height; leaf area at 10, 20, and 30 days after emergence (DAE). The physiological quality of seeds was also assessed using tests of: seed emergence; first count of germination; emergence speed index; and field emergence. It was concluded that the coating of rice seeds with dolomitic limestone and aluminum silicate does not affect seed germination and field seedling emergence. Aluminum silicate used via seed coating on cultivar IRGA 424 promoted greater leaf area, after 20 DAE. The dolomitic limestone and the aluminum silicate used via seed coating generated plants with larger dry biomass, after 20 DAE, for the cultivar IRGA 422 CL.

Aspectos da germinação de sementes de assa-peixe (Vernonia polyanthes Less.)

O objetivo do presente trabalho foi avaliar o efeito da temperatura e luz na germinação de sementes de assa-peixe (Vernonia polyanthes Less.). Para tanto foram testadas seis temperaturas constantes (15, 20, 25, 30, 35 e 40°C) e quatro combinações de temperaturas alternadas (15-20, 15-25, 20-30 e 20-35°C) na presença e ausência de luz, a qual foi fornecida durante os períodos de temperaturas mais altas, quando avaliada a alternância. As variáveis avaliadas foram: teor de água, germinação e vigor (primeira contagem e velocidade de germinação). O delineamento experimental adotado foi o inteiramente casualizado e os resultados foram submetidos à análise da variância, com as médias comparadas pelo teste de Tukey a 5% de probabilidade. Sementes da espécie V. polyanthes são fotoblásticas preferenciais, com germinação favorecida pela presença de luz, mas as maiores porcentagens de germinação e níveis de vigor dessas sementes foram obtidas em temperaturas de 25°C constante e de 15-25°C alternada, na presença de luz.