298 research outputs found

    Correlação entre caracteres agronômicos, fisiológicos e fitoquímicos em variedades de Artemisia annua L

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    The aim of this study was to estimate the correlations among agronomic, physiological and phytochemical traits of two varieties of Artemisia annua and to identify correlations that can be used in selection and breeding processes for this species. The design was completely randomized and the treatments were for Artemisia annua varieties 2/39x5x3M and 2/39x1V, which were subjected to agronomic, physiological and phytochemical evaluations. The relationship among the studied traits was estimated with Pearson's correlation coefficient, and the significance level of correlations was established by the t-test using Genes software. A significant positive correlation was found between the traits canopy volume and essential oil yield for 2/39x5x3M variety, showing that the selection of plants with a larger canopy volume would facilitate indirect selection of the trait essential oil yield. This correlation was not found for the 2/39x1V variety. In both varieties, there was a significant negative correlation between canopy volume and artemisinin content, which suggested that the selection of plants with a large canopy volume and a large number of branches should be avoided if the goal is to increase artemisinin content.O objetivo deste trabalho foi estimar as correlações existentes entre caracteres agronômicos, fisiológicos e fitoquímicos em duas variedades de Artemisia annua e identificar correlações que possam ser utilizadas em processos de seleção e melhoramento da espécie. O delineamento foi inteiramente casualizado e os tratamentos foram às variedades 2/39x5x3M e 2/39x1V de Artemisia annua, submetidas a avaliações agronômicas, fisiológicas e fitoquímicas. A relação existente entre os caracteres estudados foi estimada através do coeficiente de correlação de Pearson e o nível de significância das correlações pelo teste t, realizadas no programa Genes. Encontrou-se correlação positiva e significativa entre os caracteres volume de dossel e rendimento de óleo essencial na variedade 2/39x5x3M, evidenciando que a seleção de plantas com maior volume de dossel possibilitaria a seleção indireta para o cárater rendimento de óleo essencial. Esta correlação não foi encontrada na variedade 2/39x1V. Em ambas as variedades, observou-se correlação negativa e significativa entre volume de dossel e teor de artemisinina indicando que deve-se evitar a seleção de plantas com grande volume de dossel e número de ramificações, se o interesse do melhoramento for maior teor de artemisinina.135141Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    EXPERIMENTAL AND THEORETICAL VALIDATION OF DOUBLE COLUMN INTERNAL FIXATION THEORY FOR DISTAL FEMORAL FRACTURES

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    Purpose of the study – to experimentally compare efficiency of lateral and bilateral (lateral and medial) plate fixation of distal femoral fractures and to validate the appropriateness of double column theory of distal femur anatomy for internal fixation for these fractures.Material and methods. The authors performed a biomechanical study in two series on polyurethane models of right femur corresponding in dimensions to natural femur. After simulating a 33 C2 fracture type it was fixed by one lateral plate or two (lateral and medial) plates. After fixation the models were tested in six load ranges with maximal load from 20 to 120 kgf in cyclic mode.Results. The authors obtained a significant difference in absolute values of fragments displacement amplitude depending on fixation method. In the first series of the experiment – one plate fixed on the lateral surface of the femur – under minimal load the displacement value was reported as0.3 mm and under maximal load —1.9 mm; in the second series of experiment – two plates fixed on the lateral and medial surfaces of the femur – displacement values were reported as0.35 mm and0.95 mm respectively. Conclusion. The presence or absence of medial support after internal fixation has a profound impact on ensuring stability in cases of comminuted fractures of distal femoral fractures. In this context the use of double column theory of distal femur anatomy for internal fixation can significantly improve the treatment outcomes for such patients. After trials of minimally invasive fixation method on anatomical specimen the described theory can be implemented into the clinical practice

    Genetic dissimilarity in varieties of Artemisia annua L. based on agronomic, physiological and phytochemical characters

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    O presente estudo objetivou estimar a variabilidade genética existente entre caracteres agronômicos, fisiológicos e fitoquímicos em variedades de A. annua. O delineamento experimental foi inteiramente casualizado e os tratamentos foram as variedades Artemis, 2/39x5x3M, e 2/39x1V de A. annua, submetidas a avaliações agronômicas, fisiológicas e fitoquímicas. Para a realização das estimativas de distância genética foram geradas matrizes de dissimilaridade utilizando a distância Euclidiana e os métodos de agrupamento de Tocher e UPGMA. Além disso, avaliou-se a importância relativa dos caracteres para divergência genética pelo método de Singh. As análises foram realizadas pelo software Genes e os dendrogramas obtidos pelo NTSYS. A presença de variabilidade genética dentro das variedades permitiu a identificação de acessos dissimilares e com média elevada para as características estudadas. O número de ramificações, concentração intracelular de CO2, e o rendimento de óleo essencial foram os caracteres que mais contribuíram para a dissimilaridade genética de A. annua. Os acessos B24, C5 e C32 foram os mais promissores dentro das variedades e devem ser conservados para futuras hibridações, sendo que as hibridações mais promissoras na obtenção de populações segregantes desejadas são B24 x C5, B24 x C32 e C5 x C321621356363COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçãoThis study aimed to estimate the genetic variability among agronomic, physiological, and phytochemical characters in varieties of A. annua. The experimental design was completely randomized and the treatments were the varieties Artemis, 2/39x5x3M and 2/39x1V of A. annua, subject to agronomic, physiological and phytochemical evaluations. To estimate the genetic distances, dissimilarity matrices were generated using the Euclidean distance and the Tocher and UPGMA grouping methods. Moreover, we evaluated the relative importance of the characters for genetic divergence through the method of Singh. The analyses were performed in the Genes software and the dendrograms were obtained from the NTSYS program. The presence of genetic variability within the varieties allowed the identification of dissimilar accessions with high average for all traits. The number of branches, intracellular concentration of CO2 and oil yield were the traits that contributed most to the genetic dissimilarity of A. annua. The accessions B24, C5 and C32 were the most promising within the populations and must be conserved for future crossings, and the most promising crosses to obtain the desired segregant populations were B24 x C5, B24 x C32 and C5 x C3

    Growth Enhancement Support Scheme (GESS) and Farmers’ Fertilizer Use in Rural Nigeria

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    Fertilizer use in Nigeria is estimated at 13 kg/ha, which is far below the 200 kg/ha recommended by the Food and Agricultural Organization (FAO). The objective of this investigation was to identify the determinant factors of farmers’ participation in the Nigeria’s growth enhancement support scheme (GESS). In addition, we determined the impact of the GESS on fertilizer use in rural areas. One thousand, two hundred rural farmers were sampled across the six geopolitical zones of Nigeria. Results from the use of recursive bivariate probit model indicated that GESS significantly impacted on the access and usage of fertilizer among the rural farmers; and that contact with extension agents, ownership of mobile phones, power for charging phone batteries, value output, mobile network coverage, ability to read and write were positive determinants of rural farmers participation in the GESS; whereas increased distance to registration and collection centers, and cultural constraints to married women reduced farmers’ tendency to participate in the GESS. The findings suggest that farmers’ participation in the GESS is a critical factor for raising fertilizer use in Nigeria. This implies that food security in sub-Saharan Africa can be achieved by increasing the participation of rural farmers in the growth enhancement support scheme
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