Physiological and sanitary attributes of organic lettuce seeds treated with essential oils during storage

The use of quality seeds becomes crucial in the seed production system. In the production of organic seeds, there is a need for specific techniques. Therefore, the objective of this work was to evaluate the applications of clove, lemongrass, rosemary, eucalyptus, ginger and tea tree essential oils in different concentrations of lettuce seeds. Seed quality was determined by physical (water content), physiological (germination and vigor) and sanitary parameters, immediately after the application of essential oils and after 180 days of storage. The design was completely randomized in a factorial scheme (6x5) with four replications. The application of rosemary, ginger and tea tree essential oils to the seeds shortly after harvest did not interfere with germination. The other essential oils resulted in reduced germination and vigor. Increasing the concentration of essential oils, especially clove and lemongrass, reduced germination, vigor and incidence of fungi. It was concluded that Clove, Lemongrass, eucalyptus, ginger, Rosemary and tea tree essential oils reduced the physiological quality of lettuce seeds and inhibited the development of Alternaria sp. lettuce.The use of quality seeds becomes crucial in the seed production system. In the production of organic seeds, there is a need for specific techniques. Therefore, the objective of this work was to evaluate the applications of clove, lemongrass, rosemary, eucalyptus, ginger and tea tree essential oils in different concentrations of lettuce seeds. Seed quality was determined by physical (water content), physiological (germination and vigor) and sanitary parameters, immediately after the application of essential oils and after 180 days of storage. The design was completely randomized in a factorial scheme (6x5) with four replications. The application of rosemary, ginger and tea tree essential oils to the seeds shortly after harvest did not interfere with germination. The other essential oils resulted in reduced germination and vigor. Increasing the concentration of essential oils, especially clove and lemongrass, reduced germination, vigor and incidence of fungi. It was concluded that Clove, Lemongrass, eucalyptus, ginger, Rosemary and tea tree essential oils reduced the physiological quality of lettuce seeds and inhibited the development of Alternaria sp. lettuce

Physiological conditioning of pearl millet seeds

A pesquisa foi realizada com o objetivo de avaliar o condicionamento fisiológico de sementes de três lotes de milheto do cultivar BRS 1501. Os tratamentos consistiram da testemunha, sementes hidratadas em água pura (potencial zero) e em oito potenciais de solução aquosa de PEG 6000 (-0,1; -0,2; -0,4; -0,6; -0,8; -1,0; -1,2 e -1,4 MPa). As sementes foram avaliadas quanto ao teor de água, germinação (total e primeira contagem de germinação), emergência da plântula (total e índice de velocidade de emergência da plântula), testes de envelhecimento acelerado e de condutividade elétrica. Os resultados indicaram que as sementes de milheto emitem a raiz primária ao atingirem 33% de água, porém, como esperado, na medida em que aumentou a concentração de PEG, maior foi o período necessário para absorção de água, sendo que para os potenciais de -1,2 e -1,4 MPa as sementes não absorveram mais do que 28% de água e, assim, não emitiram a raiz primária. As sementes de milheto do cultivar BRS 1501 emitem a raiz primária com 33% de água, em potencial hídrico de zero MPa. O condicionamento fisiológico das sementes de milheto, utilizando água ou PEG 6000, não interfere no desenvolvimento inicial das plântulas.The objective of this study was to evaluate the physiological conditioning of three pearl millet seed lots of the BRS1501 commercial cultivar. The treatments consisted of untreated seeds, seeds hydrated with pure water and seeds hydrated with water of eight different potentials provided by PEG 6000 (-0.1; -0.2; -0.4; -0.6; -0.8; -1.0; -1.2 and -1.4 MPa). The seeds were evaluated for water content, germination (first count of germination and final percentage), seedling emergence (final percentage and seedling emergence speed), accelerated ageing and electrical conductivity. The results showed that pearl millet seeds emit primary roots at 33% water content, but as expected, the higher the PEG 6000 concentration, the longer the imbibition period necessary. For the potentials of -1.2 and -1.4 MPa, the seeds did not absorb more than 28% of water, and thus, did not emit primary roots. The pearl millet seeds, cultivar BRS 1501, emit the primary root at 33% water content, at a potential of zero MPa. It can be concluded that the physiological conditioning of pearl millet seeds by using pure water or PEG 6000, does not interfere in the initial seedling development.CNP

Identificação de danos mecânicos em sementes de soja

The objective of this research was to evaluate the tests for detection of mechanical damages in soybeans seeds. Thus, it was compared the use of sodium hypochlorite solution (2.0% and 5.25%), water and tetrazolium solution (0.075%). The study was conducted in soybean seeds, from the cultivars Embrapa 48 and FTS Águia with, respectively, 8.08% and 6.06% of lignin on seed coat, which were harvested mechanically and manually. The seed quality was evaluated by water content, germination and vigor (tetrazolium and electrical conductivity tests). The mechanical damages in soybean seeds, of immediate effect, can be determined by the use of the 2.0% sodium hypochlorite solution. O objetivo dessa pesquisa foi avaliar a eficiência da utilização de testes para determinar os danos mecânicos em sementes de soja. Assim, foi comparada a utilização das soluções 2,0% e 5,25% de hipoclorito de sódio, da água e da solução 0,075% de tetrazólio. A pesquisa foi conduzida com sementes de soja, cultivares Embrapa 48 e FTS Águia que têm, respectivamente,  8,08% e 6,06% de lignina no seed coato, e que foram colhidas manualmente e à máquina. Paralelamente as sementes foram avaliadas pelo teor de água, germinação e pelo vigor (testes de tetrazólio e de condutividade elétrica). Os danos mecânicos de efeitos imediatos nas sementes de soja podem ser determinados pela utilização da solução 2,0% de hipoclorito de sódio.El objetivo de esta investigación fue evaluar la eficacia de la utilización de test para determinar el daño mecánico en las semillas de soja. Así, se comparó el uso de la solución de 2,0% y 5,25% de hipoclorito de sodio, agua y solución de tetrazolio 0,075%. La investigación se llevó a cabo con semillas de soja, cultivar Embrapa 48 y FTS Águila que tienen, respectivamente, 8,08% y 6,06% de lignina en seed coato y que fueron cosechadas a mano y máquina. En paralelo las semillas fueran evaluadas por el teor de agua, germinación y vigor (tests de tetrazolio y conductividad eléctrica). Se puede determinar los daños mecánicos de efectos inmediatos de las semillas de soja mediante el uso de solución de 2,0% de hipoclorito de sodio

Restrição hídrica como método para a avaliação do vigor em sementes de soja

The objective of this study was to investigate the possibility of using hydric restriction as a method for evaluating vigor of soybean seeds. The soybean seeds, cultivar BRS 245RR, represented by four different seed lots, were characterized by germination and vigor. For the treatment of hydric restriction and temperature, the combination of substrate water potential and temperature were the following: deionized water (0.0 MPa); polyethylene glycol (PEG 6000) aqueous solution (-0.1, -0.3 and -0.5 MPa); and four temperatures (20 ºC, 25 ºC, 30 ºC, and 35 ºC), respectively. A completely randomized experimental design was used, with four replications per treatment, and the ANOVA was performed individually for each combination of temperature and water potential of substrate. According to results obtained, the test of hydric restriction has the same efficiency of the accelerated aging test in estimating vigor of soybean seeds, cv. BRS 245RR, when water potentials of -0.1 MPa or -0.3 MPa at a temperature of 25 ºC, or -0.3 MPa at a temperature of 30 ºC are used

Effect of light and different temperatures on germination of Heliocarpus popaanensis L. seeds

Heliocarpus popayanensis, conhecida popularmente como jangada-brava, é uma espécie arbórea pioneira utilizada no Brasil, principalmente, para restauração florestal. O objetivo desta pesquisa foi avaliar o efeito da luz e da temperatura na germinação das sementes de H. popayanensis. Para análise do efeito da luz, a semeadura foi realizada em caixas de plásticos transparente e preto, mantidas em germinador a 25 ºC. Na avaliação do efeito da temperatura foram analisados, em mesa termogradiente, nove intervalos de temperaturas constantes, compreendidas entre 15 ºC e 35 ºC, e duas alternadas (15-35 ºC e 20-30 ºC). Em ambos os experimentos, a semeadura foi realizada sobre duas folhas de papel mata-borrão, sendo o fotoperíodo diário de 8 h de luz. A germinação foi avaliada pela protrusão da raiz primária e pela formação de plântulas normais, e estudaram-se três lotes de sementes. Os resultados indicaram que as sementes de H. popayanensis são fotoblásticas neutras, a temperatura ótima para a germinação está entre 28,1 ºC e 30,2 ºC, temperaturas próximas a 35 ºC favorecem a superação da impermeabilidade do tegumento à água e a protrusão da raiz primária não foi eficiente na determinação da temperatura ótima para germinação, sendo a formação de plântulas normais o critério mais adequado para essa determinação.Heliocarpus popayanensis is a pioneer tree species used in Brazil mainly for forest restoration. The aim of this research was to evaluate the effect of light and temperature on the germination of H. popayanensis seeds. Seeds were put to germinate inside transparent and black plastic boxes and incubated in chambers at 25ºC for light evaluation on germination. For temperature evaluation, nine intervals of constant temperatures between 15ºC and 35ºC and two alternate temperatures (15-35ºC and 20-30ºC) were analyzed in thermo-gradient table. For both experiments, seeds were distributed on the top of two blotter paper sheets and the daily photoperiod was eight hours of light. Germination was evaluated from primary root protrusion and formation of normal seedlings, and three lots of seeds were studied. The results showed that H. popayanensis seeds are non-photoblastic, the optimum temperature interval is between 28.1ºC and 30.2ºC, temperatures around 35ºC stimulated seed impermeability overcome, and the primary root protrusion was not efficient to determine the optimum germination temperature, since the formation of normal seedlings is more indicated for this determination

Using X-ray test to evaluate the quality of Embaúba seeds (Cecropia pachystachya Trec.)

O trabalho foi realizado com o objetivo de adequar o teste de raios X para a avaliação da qualidade de sementes de embaúba e verificar a influência da formação da sua estrutura interna na germinação. As sementes foram expostas à radiação por tempos e intensidades variados, com utilização do equipamento Faxitron X-Ray, modelo MX-20 para definição da melhor combinação para visualização da morfologia interna . Definidas as condições para melhor visualização interna, as sementes foram radiografadas e classificadas em três classes, de acordo com a estrutura interna visualizada nas radiografias, em sementes totalmente formadas, parcialmente formadas e sementes não formadas. Individualmente, as sementes foram devidamente identificadas de acordo com a classe de formação e submetidas ao teste de germinação.. O teste de raios X é eficiente para avaliar as estruturas internas da semente de embaúba e a exposição por 360 segundos na intensidade de 10kV é adequada para a visualização. Há relação entre o nível de formação das sementes e os resultados do teste de germinação.The x-ray test was studied to evaluate the quality of embaúba seeds and verify the influence of the internal morphology on the seed germination. Seeds of a lot harvested in 2005 were used from the Bio Flora company. The seeds were exposed to radiation for various amounts of time and intensity, using Faxitron X-Ray equipment, model MX-20. The seeds were divided into three categories according to their internal structure visualized by radiographs in totally formed, partially formed and not formed seeds. Soon after, seeds were submitted to the germination test. The results showed that the time of 360 seconds and 10kV intensity are recommendable for visualizing internal seed structures. The x-ray test is efficient to evaluate development level of embaúba seed structure. There is correlation between seed formation and the germination test results

Condicionamento fisiológico de sementes da árvore pioneira Guazuma ulmifolia (Malvaceae) avaliado por análise computadorizada de imagens

Direct seeding is one of the most promising methods in restoration ecology, but low field seedling emergence from pioneer tree seeds still reduces its large scale applicability. The aim of this research was to evaluate seed priming for the pioneer tree species Guazuma ulmifolia. Priming treatments were selected based on seed hydration curves in water and in PEG 8000 solution. Seeds were primed in water for 16 h and in Polyethylene glycol - PEG 8000 (-0.8 MPa for 56 and 88 h) at 20ºC to reach approximately 30% water content. Half of the seed sample of each treatment was dried back to the initial moisture content (7.2%); both dried and non-dried primed seeds as well as the unprimed seeds (control) were tested for germination (percentage and rate) and vigor (electrical conductivity of seed leachates). Seedling emergence percentage and rate were evaluated under greenhouse conditions, while seedling length and uniformity of seedling development were estimated using the automated image analysis software SVIS®. Primed seeds showed the highest physiological potential, which was mainly demonstrated by image analysis. Fresh or dried primed seeds in water for 16 h and in PEG (-0.8 MPa) for 56 h, and fresh primed seeds in PEG for 88 h, improved G. ulmifolia germination performance. It is suggested that these treatments were promising to enhance efficiency of stand establishment of this species by direct seeding in restoration ecology programs.A semeadura direta é um dos métodos mais promissores para a restauração ecológica, mas a baixa emergência de plântulas em campo a partir de sementes de árvores pioneiras ainda limita sua aplicabilidade em larga escala. Avaliou-se a resposta de sementes da espécie florestal pioneira Guazuma ulmifolia ao condicionamento fisiológico. Os tratamentos foram selecionados com base em curvas de hidratação em água e em solução osmótica de Polietilenoglicol - PEG 8000. As sementes foram condicionadas em água por 16 h e em PEG 8000 (-0,8 MPa por 56 e 88 h) a 20ºC, atingindo teor de água de, aproximadamente, 30%. Metade das amostras de cada tratamento foi secada até atingir teor de água próximo ao inicial (7,2%); em seguida, avaliou-se o desempenho das sementes condicionadas submetidas ao não à secagem, além de sementes não condicionadas (testemunha), quanto à germinação (porcentagem e velocidade) e o vigor (condutividade elétrica dos exudatos das sementes). A porcentagem e a velocidade de emergência de plântulas foram avaliadas em condições de casa de vegetação, enquanto que o comprimento de plântulas e a uniformidade de desenvolvimento das plântulas foram estimados usando o software de análise computadorizada de imagens de plântulas SVIS®. As sementes condicionadas fisiologicamente apresentaram potencial fisiológico superior, demonstrado principalmente pelos resultados da análise de imagens. Assim, as sementes condicionadas em água durante 16 h ou em PEG durante 88 h, ambas não submetidas à secagem subsequente, e as condicionadas em PEG durante 56 h e submetidas a secagem, beneficiaram o desempenho germinativo de G. ulmifolia. Sugere-se que esses tratamentos são promissores para aumentar a eficiência de estabelecimento de estande dessa espécie via semeadura direta em programas de restauração ecológica

Germination test of seeds of Parapiptadenia rigida (Benth.) Brenan (Fabaceae)

Parapiptadenia rigida (angico vermelho) é uma espécie florestal brasileira que vem sendo utilizada para restauração florestal e para a extração de madeira. No entanto, as informações sobre o teste de germinação para as sementes dessa espécie são escassas, sendo necessários estudos adicionais visando a definição e a padronização de metodologias mais adequadas. Dessa forma, os efeitos de nove intervalos de temperatura, entre 15°C e 35°C, foram avaliados em mesa termogradiente com fotoperíodo diário de 8 horas; além disso, foram analisadas quatro condições de substratos (sobre papel, rolo de papel, entre vermiculita e sobre vermiculita) em germinadores a 25°C e 30°C, com o mesmo fotoperíodo. Os substratos entre e sobre vermiculita foram testados, também, na ausência de luz, na temperatura de 25°C. Com os resultados obtidos, conclui-se que o teste de germinação de sementes de P. rigida deve ser realizado na temperatura de 25ºC, utilizando-se o substrato entre vermiculita, na presença ou ausência de luz.Parapiptadenia rigida is a Brazilian tree species that has been used for forest restoration and wood extraction. However, the information available about the germination test with the seeds of this species is scarce, and additional studies are neede define and standardize the most favorable methodologies. Therefore, the effects of nine temperature intervals between 15°C and 35°C were evaluated in a thermo-gradient table with a daily photoperiod of 8 hours and four substrate conditions (on top of the paper, paper roll, in vermiculite and on top of vermiculite) were analyzed in chambers with the same photoperiod, at 25°C and 30°C. The substrates in and on top of vermiculite were also tested without light, at 25ºC. The results showed that the germination test of P. rigida seeds should be carried out at 25°C, with the substrate in vermiculite, with or without light

Germination and seedling morphology of four South American Smilax (Smilacaceae)

Species of Smilax,, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic. coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics. Rev. Biol. Trop. 60 (1): 495-504. Epub 2012 March 01.FAPESP (Sao Paulo Council for Research) BIOTAFAPESP (Sao Paulo Council for Research) - BIOTA [05/54984-5, 05/58964-9]CNPqCNP

Magnolia ovata St. Hil. seed conservation

A pesquisa foi regularizada com o objetivo de estudar a influência do teor de água da semente e da temperatura de armazenamento sobre a conservação das sementes de Magnolia ovata (Magnoliaceae), uma árvore nativa brasileira. Para tanto, sementes recém colhidas com 23,5% de água foram submetidas à secagem para a obtenção de sementes com os teores de água de 17,4%, 10,9% e 7,1%. Em seguida, as sementes foram acondicionadas em sacos de polietileno e armazenadas a 15ºC e a 20ºC. As sementes foram armazenadas por 180 dias e avaliadas mensalmente quanto ao teor de água, à emergência, ao índice e à velocidade de emergência da plântula e ao comprimento e à massa da matéria seca da plântula. A conservação das sementes de Magnolia ovata é favorecida pela secagem das sementes; as condições favoráveis para a conservação são sementes com 10,9% de água e 15ºC ou 20ºC de temperatura do ambiente de armazenamento.The research aimed to study the influence of the seed moisture content and storage temperature on Magnolia ovata (Magnoliaceae) seed conservation, a native Brazilian tree. Thus, recently harvested seeds with moisture content of 23.5% were dried to obtain seed lots with moisture content of 17.4 %, 10.9% and 7.1%. Then, seeds were placed in polyethylene bags and stored at 15ºC and 20ºC. Seeds were stored for 180 days, and were evaluated monthly for moisture content, seedling emergence, emergence index, speed of seedling emergence, seedling length and seedling dry mass. The physiological potential of M. ovata seeds was favored by drying seeds; seed conservation was favored by seed with 10.9% moisture content and 15ºC or 20ºC storage temperature.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq