974 resultados para 100-250 µm
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This study aimed to determine the indole-3-butyric acid (IBA) requirement and proper concentration for Caesalpinia echinata rooting in a hydroponic system for plantlet production. The experiment was conducted in a greenhouse of the 'Faculdade de Ciencias Agrarias e Veterinarias', UNESP, in Jaboticabal, São Paulo state. The vegetal material consisted of 160 stem cuttings that were 11 to 12 cm in length with two pairs of leaves, prepared from young seedlings. The cutting bases were treated by slow immersion in 5% ethanol solution containing 0, 100, 200 and 400 mg L-1 of IBA during 14 hours and by fast immersion in 50% ethanol solution containing 0, 1000, 3000 and 5000 mg L-1 of IBA during 5 seconds. The cuttings were maintained in the hydroponic system for 90 days and, for additional 90 days in plastic bags containing substrate (Plantmax (R)) under intermittent mist. After 90 and 180 days of rooting, the percentage of cuttings that survived, the rooting percentage and the number and length of adventious root were evaluated. Cuttings should be treated with IBA at 100 mg L-1 for 14 hours and placed to root in a hydroponic system.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O trabalho teve como objetivo estudar a eficiência dos testes de vigor para identificação do potencial fisiológico em sementes de Guazuma ulmifolia Lam. O estudo foi desenvolvido no Laboratório de Análise de Sementes – UNESP/Jaboticabal/SP, utilizando-se quatro lotes de sementes: sendo lotes I e II, coletados no município de Jaboticabal em 2000 e 2001, respectivamente lote III em Santa Rita do Passo Quatro e lote IV, em Luiz Antonio, ambos em 2001. Para superação da dormência, realizou-se a escarificação das sementes com ácido sulfúrico durante 50 minutos e lavagem em água corrente durante 20 minutos. Foram avaliados: teor de água, percentual de germinação, primeira contagem, índice de velocidade de germinação e condutividade elétrica, realizada com diferentes quantidades de sementes (50, 75, 100), postas para embeber em copos de plástico contendo 50 e 75mL de água deionizada, durante 72 horas à 250 C. As sementes do lote III apresentaram potencial fisiológico superior às sementes dos demais lotes estudados. Para o teste de condutividade elétrica são necessários outros estudos, visando à possibilidade de uso como teste padrão de vigor para a espécie, enquanto que os testes de primeira contagem e índice de velocidade de germinação mostraram-se adequados para avaliação do vigor dos lotes.
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At present, the Brazilian market prefers cabbage (Brassica oleracea var. capitata) of smaller size, which can be achieved by increasing population density; yet this management can alter the optimum rate of nitrogen (N), its second most required nutrient. This study was conducted in the Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil, from February to June 2004. The objective was to evaluate the effect of population density: 31 250 (DI) and 46 875 plants ha(-1) (D2) with 0, 100, 200 and 300 kg N ha-1 on the growth and production of cabbage Astrus. The experimental design consisted of randomized blocks with a 2 x 4 factorial arrangement and three replicates. Statistical analysis were a variance analysis (F test), the Tukey test for population density averages and polynomial regression for the N rates. In D1, an increase was recorded in the number of inner and outer leaves, dry matter of inner and outer leaves, the stem diameter at the insertion of the head, and the stem dry and fresh matter. The maximum size of the plant in D2 was 1.57 kg and was obtained with 300 kg N ha(-1), while in D1 it was 2.1 kg and was obtained with 244 kg N ha(-1). The optimal economic rate in 131 was 227.1 kg N ha(-1). The highest yield (72.7 t ha(-1)) was obtained with the highest N rate in D2. Smaller cabbage heads, commercially preferred, were obtained without the application of N, regardless of plant population.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A nested-PCR assay for detection of Xylella fastidiosa in citrus plants and sharpshooter leafhoppers
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Aims: Detection of Xylella fastidiosa in citrus plants and insect vectors.Methods and Results: Chelex 100 resin matrix was successfully standardized allowing a fast DNA extraction of X. fastidiosa. An amplicon of 500 bp was observed in samples of citrus leaf and citrus xylem extract, with and without symptoms of citrus variegated chlorosis, using PCR with a specific primer set indicating the presence of X. fastidiosa. The addition of insoluble acid-washed polyvinylpyrrolidone (PVPP) prior to DNA extraction of insect samples using Chelex 100 resin together with nested-PCR permitted the detection of X. fastidiosa within sharpshooter heads with great sensitivity. It was possible to detect up to two bacteria per reaction. From 250 sharpshooter samples comprising four species (Dilobopterus costalimai, Oncometopia facialis, Bucephalogonia xanthopis and Acrogonia sp.), 87 individuals showed positive results for X. fastidiosa in a nested-PCR assay.Conclusions: the use of Chelex 100 resin allowed a fast and efficient DNA extraction to be used in the detection of X. fastidiosa in citrus plants and insect vectors by PCR and nested-PCR assays, respectively.Significance and Impact of the study: the employment of efficient and sensitive methods to detect X. fastidiosa in citrus plants and insect vectors will greatly assist epidemiological studies.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fruit of 'Satsuma Okitsu' tangerine are similar to 'Ponkan', with a maturation period starting in January, and supplying the Brazilian market during the off-season. Fruits of this cultivar have to be harvested with green peel, which is not well accepted by the market. This study aimed to evaluate the degreening of 'Satsuma Okitsu' tangerine using ethephon (2-chloroethyl phosphonic acid). The fruits were harvested with stems when they reached soluble solids: acidity ratio of >7. After selection, the fruits were treated with the Imazalil fungicide (200 ml 100 L-1) for two min and after 24 hours fruits were dipped in different concentrations of ethephon (Ethrel 240): control, 250, 500 and 1000 ppm. The fruits were analyzed every 3 days during 9 days of storage at 18 +/- 2 degrees C, 85 +/- 5% RH for appearance, weight loss, rind color, soluble solids, acidity and ascorbic acid content. The experiment was conducted as a factorial in a completely randomized design. The treatment with Ethrel provided the best flavedo or rind degreening which made these fruits turn orange with greater intensity and showed good quality during 9 days at 18 degrees C, besides increase in weight loss.
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A retenção de Se pelos colóides do solo constitui importante processo para a manutenção da sanidade ambiental. A informação sobre a adsorção de Se em solos altamente intemperizados é restrita e existem poucos padrões quantitativos disponíveis para a definição de estratégias de remediação de áreas contaminadas. Quantidades crescentes de Se (5, 10, 25, 50, 100 e 250 mg L-1), na forma de Na2SeO3, foram adicionadas a amostras de dez Latossolos brasileiros [três Latossolos Vermelho-Amarelos (LVA-1, LVA-2 e LVA-3), dois Latossolos Vermelhos (LV-1 e LV-2), um Latossolo Vermelho eutroférrico (LVef), um Latossolo Vermelho acriférrico (LVwf), dois Latossolos Amarelos (LA-1 e LA-2) e um Latossolo Amarelo acriférrico (LAwf)]. Isotermas de adsorção foram construídas e foi verificado o ajuste dos resultados experimentais aos modelos de Langmuir e de Freundlich. A equação de Langmuir ajustou melhor os resultados de adsorção de Se do que a isoterma de Freundlich. Todas as isotermas apresentaram o formato tipo-L (exponencial), com exceção daquelas obtidas para o LVA-1 e para o LVA-2, que apresentaram comportamento tipo-C (linear). Valores de adsorção máxima (Ads máx), estimada pelo modelo de Langmuir, variaram de 135 (LVA-3) a 2.245 mg kg-1 (LA-1), enquanto os coeficientes de afinidade (K L) estiveram entre 0,002 (LVA-2) e 0,326 (LVA-3). A constante de afinidade estimada pelo modelo de Freundlich (Kf) variou de 13,7 (LVA-2) a 180,1 (LAwf). A adsorção máxima de Se foi mais elevada no LVef e nos Latossolos ácricos (LAwf e LVwf), enquanto os maiores valores de Kf foram encontrados no LV-2, LVef, LVA-3 e LVwf. Não houve correlação entre os atributos dos solos e as constantes de Langmuir. Valores de Kf correlacionaram-se com os teores de argila (r = 0,42*) e com a capacidade de troca de ânions (r = 0,64*).
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Genomewide marker information can improve the reliability of breeding value predictions for young selection candidates in genomic selection. However, the cost of genotyping limits its use to elite animals, and how such selective genotyping affects predictive ability of genomic selection models is an open question. We performed a simulation study to evaluate the quality of breeding value predictions for selection candidates based on different selective genotyping strategies in a population undergoing selection. The genome consisted of 10 chromosomes of 100 cM each. After 5,000 generations of random mating with a population size of 100 (50 males and 50 females), generation G(0) (reference population) was produced via a full factorial mating between the 50 males and 50 females from generation 5,000. Different levels of selection intensities (animals with the largest yield deviation value) in G(0) or random sampling (no selection) were used to produce offspring of G(0) generation (G(1)). Five genotyping strategies were used to choose 500 animals in G(0) to be genotyped: 1) Random: randomly selected animals, 2) Top: animals with largest yield deviation values, 3) Bottom: animals with lowest yield deviations values, 4) Extreme: animals with the 250 largest and the 250 lowest yield deviations values, and 5) Less Related: less genetically related animals. The number of individuals in G(0) and G(1) was fixed at 2,500 each, and different levels of heritability were considered (0.10, 0.25, and 0.50). Additionally, all 5 selective genotyping strategies (Random, Top, Bottom, Extreme, and Less Related) were applied to an indicator trait in generation G(0), and the results were evaluated for the target trait in generation G(1), with the genetic correlation between the 2 traits set to 0.50. The 5 genotyping strategies applied to individuals in G(0) (reference population) were compared in terms of their ability to predict the genetic values of the animals in G(1) (selection candidates). Lower correlations between genomic-based estimates of breeding values (GEBV) and true breeding values (TBV) were obtained when using the Bottom strategy. For Random, Extreme, and Less Related strategies, the correlation between GEBV and TBV became slightly larger as selection intensity decreased and was largest when no selection occurred. These 3 strategies were better than the Top approach. In addition, the Extreme, Random, and Less Related strategies had smaller predictive mean squared errors (PMSE) followed by the Top and Bottom methods. Overall, the Extreme genotyping strategy led to the best predictive ability of breeding values, indicating that animals with extreme yield deviations values in a reference population are the most informative when training genomic selection models.
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Este trabalho teve por objetivo a avaliação da vida útil potencial de carambolas cv. Golden Star, minimamente processadas, armazenadas em diferentes tipos de embalagens plásticas, para a concepção da atmosfera modificada. Os frutos colhidos fisiologicamente maturos apresentaram coloração verde-amarelada, sólidos solúveis (SS) médios de 6,8 ºBrix e massa média de 185 g. Antes da aplicação dos tratamentos, os frutos foram selecionados, higienizados em solução de hipoclorito de sódio (NaOCl) a 100 mg. L-1, resfriados por 12 horas a 15 ± 0,5 °C, seccionados transversalmente, sendo então novamente higienizados em solução de NaOCl a 10 mg.L-1, por 3 minutos. em seguida, os pedaços em forma de estrelas foram acondicionados em bandejas rígidas de poliestireno, com capacidade para 250 g, e revestidas com os seguintes materiais: T1: filme plástico perfurado de polietileno de baixa densidade (PEBD), de 0,006 mm; T2: filme plástico poliolefínico com antiembassamento da Dupont® (AGF), de 0,015 mm; T3: filme plástico poliolefínico da Dupont® (HF), de 0,015 mm; T4: filme plástico de PEBD, de 60 µm; T5: filme plástico de PEBD, de 80 µm; T6: filme plástico de polipropileno (PP), de 22 µm, e T7: bandeja rígida de polietileno tereftalato (PET), com capacidade para 500 mL, com tampa do mesmo material. As embalagens foram então armazenadas em câmara frigorífica a 12 ± 0,5 °C e 90 ± 3% de U.R, por 18 dias. Observou-se que não houve diferença significativa quanto aos sólidos solúveis (SS) e acidez titulável (AT). O maior número de microrganismos e valor de pH foram observados nos frutos embalados nos filmes plásticos de PEBD de 0,006 mm, AGF e HF de 0,015 mm da Dupont®. Entretanto, os frutos acondicionados nas embalagens PET apresentaram o maior teor de ácido ascórbico. da mesma forma, somente nas embalagens PET é que se conseguiu modificação atmosférica eficiente do ponto de vista da manutenção dos atributos de qualidade durante o AR. Assim, esse tratamento proporcionou adequado controle microbiológico e manutenção das características de qualidade por 18 dias para as carambolas minimamente processadas.
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The 100% cotton fabric (CO)* treated with plasma of methane CH4 has direct application in all areas that needs of aqueous solutions repellent material like coatings and uniforms applied biomedical, aeronautics, and automobile between others. 100% cotton fabric (CO) samples were treated by plasma with two differents atmosphere: Methane gas (CH4), treatment time was varied in 10 in 10 min. until 60 min., and mixture methane/argon (CH4/Ar), it was varied the proportion 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 e 9:1, with treatment time of 30 minutes. In both, the fluxe was 5 sccm (second cubic centimeter), pressure 6 mbar, voltage 490 V and current 0,15A. The objective of work was measure the superficial tension of 100% CO then it treated with plasma, using contact angle measures of water and glycerol with the surface. The samples were tested after treatment, with 8 and 12 months to verify the superficial modification effects. It was verified an increase of hydrophobility with the Sessile drop values varied between 116,69º to 137,85º and it carried on after 12 months. The no treated samples shows contact angle equal 0º. OES analysis and Raman spectroscopy were accomplished. In the SEM analysis was verified oligomers. The plasma treatment is correct environmental, It turning greater than conventional treatments