Biometria e qualidade fisiológica de sementes de diferentes matrizes de Tabebuia chrysotricha (Mart. Ex A. DC.) Stand I.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cruzamentos entre linhagens tropicais de milho doce e testadores com introgressão de germoplasma temperado

Pós-graduação em Agronomia (Horticultura) - FCA

Uso do efeito xênia em híbridos comerciais de milho (Zea mays L.)

Pós-graduação em Agronomia - FEIS

Potential of antimicrobial volatile organic compounds to control Sclerotinia sclerotiorum in bean seeds

The objective of this work was to evaluate the potential of an artificial mixture of volatile organic compounds (VOCs), produced by Saccharomyces cerevisiae, to control Sclerotinia sclerotiorum in vitro and in bean seeds. The phytopathogenic fungus was exposed, in polystyrene plates, to an artificial atmosphere containing a mixture of six VOCs formed by alcohols (ethanol, 3-methyl-1-butanol, 2-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and ethyl octanoate), in the proportions found in the atmosphere naturally produced by yeast. Bean seeds artificially contamined with the pathogen were fumigated with the mixture of VOCs in sealed glass flasks for four and seven days. In the in vitro assays, the compounds 2-methyl-1-butanol and 3-methyl-1-butanol were the most active against S. sclerotiorum, completely inhibiting its mycelial growth at 0.8 µL mL-1, followed by the ethyl acetate, at 1.2 µL mL-1. Bean seeds fumigated with the VOCs at 3.5 µL mL-1 showed a 75% reduction in S. sclerotiorum incidence after four days of fumigation. The VOCs produced by S. cerevisiae have potential to control the pathogen in stored seeds.

Effect of Fusarium graminearum and infection index on germination and vigor of maize seeds

Pathogens in maize (Zea mays) seeds cause serious problems, such as the loss of their capacity to germinative. The objectives of this study were to identify the optimal period for infection of maize seeds on agar colonized by Fusarium graminearum, when incubated for 4, 8, 16 and 32 h, and to evaluate the effect of the fungus on the germination and vigor of seeds with different infection levels. After the respective incubation periods, the seeds were removed from the culture medium and submitted to the blotter test for 3 min with and without superficial disinfection with 1% solution of sodium hypochlorite. Once the optimal period for seed incubation was identified, seeds from the same sample were again placed on the colonized agar for infection. Germination and vigor tests (accelerated aging and cold test) were performed with a mixture of healthy seeds (placed on PDA medium) and inoculated seeds, resulting in seeds with 0, 20, 40, 60, 80 and 100% rates of infection. The results showed that a period of 32 h was long enough to obtain seeds infected by the pathogen. There were no significant effects of fungal infection on seed germination at any of the infection levels, probably due to the high vigor of the maize seed lot tested. Regarding vigor tests, infection levels differed significantly from the control (0% infection), but there were no significant differences among the infection levels.

Note on the germination of Vochysia tucanorum seeds treated with growth regulators

(Note on the germination of Vochysia tucanorum seeds treated with growth regulators). The aim of this work was to evaluate the germination response of Vochysia tucanorum Mart. seeds treated with GA3 and CEPA and germinated under white light or darkness. Newly collected seeds from a Cerrado area were stored for 14 days at two temperatures (25 °C ± 2 and 7 °C ± 1). After the storage period the seeds were pre-treated with distilled water (control), gibberellic acid (GA3), 2-chloroethylphosphonic acid (CEPA) and a mixture of GA3 + CEPA. Following this, the seeds were sown in Petri dishes on filter paper moistened with distilled water and germinated in either darkness or white light. The results suggest that seeds are non-photoblastic and non-dormant, however a photoblastic behavior emerges when the seeds were previously stored at low temperature and imbibed in CEPA and GA3 solutions. In general, there is no difference between the 7 °C and 25 °C storage temperatures. The germination of seeds pre-treated with CEPA and CEPA + GA3 under white light was faster as compared to the distilled water control, and the effect of the CEPA + GA3 mixture was more pronounced than CEPA alone. Thus, the germination rate of V. tucanorum seeds can be improved by treatment with CEPA or CEPA + GA3 under white light.

Anti-inflammatory and antinociceptive activities of an acid fraction of the seeds of Carpotroche brasiliensis (Raddi) (Flacourtiaceae)

Carpotroche brasiliensis is a native Brazilian tree belonging to the Oncobeae tribe of Flacourtiaceae. The oil extracted from its seeds contains as major constituents the same cyclopentenyl fatty acids hydnocarpic (40.5%), chaulmoogric (14.0%) and gorlic (16.1%) acids found in the better known chaulmoogra oil prepared from the seeds of various species of Hydnocarpus (Flacourtiaceae). These acids are known to be related to the pharmacological activities of these plants and to their use as anti-leprotic agents. Although C. brasiliensis oil has been used in the treatment of leprosy, a disease that elicits inflammatory responses, the anti-inflammatory and analgesic activities of the oil and its constituents have never been characterized. We describe the anti-inflammatory and antinociceptive activities of C. brasiliensis seed oil in acute and chronic models of inflammation and in peripheral and central nociception. The mixture of acids from C. brasiliensis administered orally by gavage showed dose-dependent (10-500 mg/kg) anti-inflammatory activity in carrageenan-induced rat paw edema, inhibiting both the edema by 30-40% and the associated hyperalgesia. The acid fraction (200 mg/kg) also showed significant antinociceptive activity in acetic acid-induced constrictions (57% inhibition) and formalin-induced pain (55% inhibition of the second phase) in Swiss mice. No effects were observed in the hot-plate (100 mg/kg; N = 10), rota-road (200 mg/kg; N = 9) or adjuvant-induced arthritis (50 mg/kg daily for 7 days; N = 5) tests, the latter a chronic model of inflammation. The acid fraction of the seeds of C. brasiliensis which contains cyclopentenyl fatty acids is now shown to have significant oral anti-inflammatory and peripheral antinociceptive effects.

Chemical and biological treatments of castor bean seeds: effects on germination, emergence and associated microorganisms

The effect of chemical and biological treatments on castor bean emergence, seedling vigor, dry matter production, and also the control of microorganisms associated with seeds of the AL Guarany 2002 and Lyra cultivars, was evaluated. The products tested were carbendazim + thiram, carboxin + thiram and a product based on Trichoderma. Total seed and seedling emergence were evaluated at 27 days after sowing whereas dry matter production was verified for plants removed 45 days after sowing. The Guarany 2002 AL cultivar had a higher incidence of microorganisms than the Lyra cultivar. The chemical treatment was 100% effective in controlling fungi but the biological treatment did not reduce microorganism incidence on the seeds. Chemical treatment resulted in plants with more dry matter and the best results were for carbendazim + thiram and carboxin + thiram at doses of 60 g + 140 g and 50 g + 50 g/100 kg of seeds, respectively. The carbendazim + thiram mixture was the only treatment which was statistically higher for total emergence whereas the biological treatment increased emergence only for the Lyra cultivar, thus demonstrating its lower efficiency. The importance of fungicides to control pathogens associated with seeds was discussed.

Effect of Fusarium graminearum and infection index on germination and vigor of maize seeds

Patógenos em sementes de milho (Zea mays) causam sérios problemas, como a perda de sua capacidade germinativa. O objetivo do trabalho foi determinar qual o melhor tempo para infecção das sementes de milho com Fusarium graminearum, para posterior avaliação dos danos causados pelo fungo na germinação e vigor das mesmas. As sementes foram colocadas sobre meio de BDA contendo o patógeno e incubadas por 4, 8, 16 e 32 h. Após os respectivos períodos de incubação, estas foram submetidas ao teste de sanidade (papel de filtro), com duas variações, sem e com assepsia superficial, usando hipoclorito de sódio a 1% de cloro ativo, por 3 min. Determinado o melhor tempo para infecção, outras sementes foram infetadas com o patógeno, para realização dos testes de germinação e vigor (envelhecimento acelerado e teste de frio) com uma mistura de sementes sadias (colocadas sobre o meio BDA) e sementes inoculadas, resultando em 0, 20, 40, 60, 80 e 100% de sementes infetadas com o fungo em estudo. Os resultados obtidos mostraram que o período de incubação de 32 h foi suficiente para se obter sementes infetadas. Com relação à germinação, não houve diferenças significativas entre os diferentes níveis de infecção, provavelmente devido ao alto vigor das sementes de milho testadas. Quanto aos testes de vigor, os níveis de infecção diferiram significativamente da testemunha, apesar de não terem diferido entre si.

Note on the germination of Vochysia tucanorum seeds treated with growth regulators

(Nota sobre a germinação de sementes de Vochysia tucanorum tratadas com reguladores vegetais). O objetivo deste trabalho foi avaliar a resposta germinativa sob luz branca e escuro de sementes de Vochysia tucanorum Mart. tratadas com GA3 e CEPA. Sementes recém-coletadas de uma área de Cerrado foram armazenadas durante 14 dias em duas temperaturas (25 ± 2 °C e 7 ± 1 °C). Após o período de armazenamento, as sementes foram pré-tratadas com água destilada (controle), ácido giberélico (GA3), ácido 2-cloroetilfosfônico (CEPA) e uma mistura de GA3 + CEPA; em seguida, as sementes foram semeadas em placas de Petri sobre papel filtro umedecido com água destilada e colocadas para germinar em escuro e sob luz branca. Os resultados sugerem que as sementes não são fotoblásticas nem dormentes, no entanto um comportamento fotoblástico emerge quando as sementes foram previamente armazenadas em baixa temperatura e embebidas em soluções de GA3 e CEPA. em geral, não houve diferença entre as temperaturas de armazenamento de 7 °C e 25 °C. A germinação sob luz branca de sementes pré-tratadas com CEPA + GA3 e CEPA foi antecipada, em comparação com o controle de água destilada, sendo que o efeito da mistura CEPA + GA3 foi mais pronunciado do que o de CEPA sozinho. Assim, a taxa de germinação de sementes de V. tucanorum, sob luz branca, pode ser melhorada pela embebição das mesmas em soluções de CEPA ou de CEPA + GA3.

Content of essential oil of fennel seeds in two different stages of development

This experiment was carried out at Plant Production Sector, Agronomical Science College-Botucatu, S.P., Brazil, in March, 2000. The aim of this assay was to determine the yield of essential oil of fennel (Foeniculum vulgare Miller) in different stages of development. Essential oils were prepared by hydrodistillation from the seeds using of Clevenger apparatus. The water utilized for the extraction of essential oil was sufficient to cover 100 g of seeds and the mixture was distilled for three hours. The volume of essential oil in the graduated side -arm of Clevenger apparatus was observed. There were no significative difference statistic was observed (Tukey 5%) in percentage (v/m) of oil content, based on dry weight of green seeds compared with dry weight of mature seeds, when they were harvested in two different stages of development. There was significative difference statistic between data obtained of humidity content of green seeds when these were compared with mature seeds. These results shows that others specifics studies about adaptation of fennel in tropical conditions are necessary, because the obtained data were different of data described on literature.

Evaluating of the activity antioxidant and fatty acids profile of lychee seeds (Litchi chinensis SONN.)

Purpose: The purpose of this paper is to characterize lychee seeds regarding their centesimal composition, and also to evaluate their antioxidant potential and fatty acid profile. Design/methodology/approach: To obtain the extract, dehydrated and grinded seeds were extracted with ethyl alcohol for 30 min, at a proportion of 1:3 of seeds:ethyl alcohol, under continuous agitation, at room temperature. Afterwards, the mixture was filtered and the supernatant subjected to a rotoevaporator at 40oC aiming to determine, by direct weighing, the extract dry matter yield. Findings: The largest found values went to the total carbohydrates (72.75 percent). In the oil from the lychee seeds there was a high percentage of unsaturated fatty acids, the main component being linoleic, considered an essential fatty acid. Research limitations/implications: Implies the identification of compounds biativos extracted from seeds of tropical and subtropical fruits, and to prevent certain types of diseases. Originality/value: The article tries to identify new source of phenolic compounds extracted from fruit. © Emerald Group Publishing Limited.

SEQUENTIAL SAMPLING AND MICROSATELLITES FOR EVALUATION OF THE GENETIC QUALITY IN CORN SEEDS LOTS

In the seed production system, genetic purity is one of the fundamental requirements for its commercialization. The present work had the goal of determined the sample size for genetic purity evaluation, in order to protect the seed consumer and the producer and to evaluate the sensitivity of microsatellite technique for discriminating hybrids from their respective relatives and for detecting mixtures when they are present in small amounts in the samples. For the sequential sampling, hybrid seeds were marked and mixed in with the seed lots, simulating the following levels of contamination: 0.25, 0.5, 1.0, 2.0, 4.0, and 6.0%. After this, groups of 40 seeds were taken in sequence, up to a maximum of 400 seeds, with the objective of determining the quantity of seeds necessary to detect the percentage of mixture mentioned above. The sensitivity of microsatellite technique was evaluated by mixing different proportions of DNA from the hybrids with their respective seed lines. For the level of mixture was higher than 1:8 (1P1:8P2; 8P1:1P2), the sensitivity of the marker in detecting different proportions of the mixture varied according to the primer used. In terms of the sequential sampling, it was verified that in order to detect mixture levels higher than 1% within the seed lot- with a risk level for both the producer and the consumer of 0.05- the size of the necessary sample was smaller than the size needed for the fixed sample size. This also made it possible to reduce costs, making it possible to use microsatellites to certify the genetic purity of corn seeds lots.

Reserve carbohydrates and lipids from the seeds of four tropical tree species with different sensitivity to desiccation

Considering the importance of water content for the conservation and storage of seeds, and the involvement of soluble carbohydrates and lipids for embryo development, a comparative study was carried out among the seeds of Inga vera (ingá), Eugenia uniflora (pitanga), both classified as recalcitrant, and Caesalpinia echinata (brazilwood) and Erythrina speciosa (mulungu), considered as orthodox seeds. Low concentrations of cyclitols (0.3-0.5%), raffinose family oligosaccharides (ca. 0.05%) and unsaturated fatty acids (0-19%) were found in the seeds of ingá and pitanga, while larger amounts of cyclitols (2-3%) and raffinose (4.6-13%) were found in brazilwood and mulungu, respectively. These results, in addition to higher proportions of unsaturated fatty acids (53-71%) in orthodox seeds, suggested that sugars and lipids played important role in water movement, protecting the embryo cell membranes against injuries during dehydration.

Nutritional reserves of Vochysiaceae seeds: chemical diversity and potential economic uses

Contents of proteins, carbohydrates and oil of seeds of 57 individuals of Vochysiaceae, involving one species of Callisthene, six of Qualea, one of Salvertia and eight of Vochysia were determined. The main nutritional reserves of Vochysiaceae seeds are proteins (20% in average) and oils (21. 6%). Mean of carbohydrate contents was 5. 8%. Callisthene showed the lowest protein content (16. 9%), while Q. cordata was the species with the highest content (30% in average). The contents of ethanol soluble carbohydrates were much higher than those of water soluble carbohydrates. Oil contents lay above 20% for most species (30. 4% in V. pygmaea and V. pyramidalis seeds). The predominant fatty acids are lauric (Q. grandiflora), oleic (Qualea and Salvertia) or acids with longer carbon chains (Salvertia and a group of Vochysia species). The distribution of Vochysiaceae fatty acids suggests for seeds of some species an exploitation as food sources (predominance of oleic acid), for other species an alternative to cocoa butter (high contents or predominance of stearic acid) or the production of lubricants, surfactants, detergents, cosmetics and plastic (predominance of acids with C20 or C22 chains) or biodiesel (predominance of monounsaturated acids). The possibility of exploitation of Vochysiaceae products in a cultivation regimen and in extractive reserves is discussed.