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Campinas, Brazil

Montanari R.,State University of Mato Grosso do Sul | Souza G.S.A.,State University of Mato Grosso do Sul | Pereira G.T.,Sao Paulo State University | Marques Jr. J.,Sao Paulo State University | And 2 more authors.
Precision Agriculture | Year: 2012

Spatial sampling designs used to characterize the spatial variability of soil attributes are crucial for science studies. Sample planning for the interpolation of a regionalized variable may use several criteria, which could be best selected from an estimated semivariogram from a previously established grid. The objective of this study was to optimize the procedure for scaled semivariogram use to plan soil sampling in sugarcane fields in the Alfisol and Oxisol regions of Jaboticabal Town in São Paulo State, Brazil. A scaled semivariogram for several soil chemical attributes was estimated from the data obtained from two grids positioned on a sugarcane field area, sampled at a depth of 0.0-0.5 m. The research showed that regular grids with uniform intervals did not express the real spatial variability of the soil attributes of Oxisols and Alfisols in the study area. The calculated final sampling density based on the scaled parameters of the semivariogram was one sample for each 2 ha in Area 1 (convex landscape) and one sample for each 1 ha in Area 2 (linear landscape), as indicated by SANOS 0.1 software. The combined use of the simulation programs and scaled semivariograms can be used to define sampling points. These results may help in soil fertility mapping and thereby improve nutrient management in sugarcane crops. © 2012 Springer Science+Business Media, LLC. Source

Siqueira M.V.B.M.,University of Sao Paulo | Pinheiro T.T.,University of Sao Paulo | Borges A.,University of Sao Paulo | Valle T.L.,Agronomic Institute | And 2 more authors.
Biochemical Genetics | Year: 2010

Using nine microsatellite loci, we investigated genetic structure and diversity in 83 Brazilian cassava accessions, including several landraces, in the Cerrado biome in Mato Grosso do Sul, Brazil. All nine loci were polymorphic, averaging 6.00 alleles per locus. Treating each of seven municipalities as a cassava group or population, they averaged 3.5 alleles per locus, with 97% polymorphic loci, high values for observed heterozygosity (0.32) and gene diversity (0.56). Total genetic variability was high (0.668), and most of this genetic variability was concentrated within municipalities (0.577). Cluster and structure analyses divided accessions into two major clusters or populations (K = 2). Also, a significant genetic versus geographic correlation was found (r = 0.4567; P < 0.0260). Migratory routes in the Cerrado are considered main contributors to the region's high cassava diversity and spatial genetic structure, amplifying interactions between traditional farmers and the evolutionary dynamics of this crop. © 2010 Springer Science+Business Media, LLC. Source

De Almeida L.F.R.,Institute of Biosciences of Botucatu | De Portella R.O.,Institute of Biosciences of Botucatu | Bufalo J.,Institute of Biosciences of Botucatu | Marques M.O.M.,Paulista University | And 3 more authors.
PLoS ONE | Year: 2016

The present study aimed to evaluate the effect of seasonal and diurnal events on the chemical profile of the essential oil obtained from the leaves of Copaifera langsdorffii Desf. This study was performed in a Brazilian savanna named Cerrado. We identified the best harvesting period for obtaining the highest amount of compounds used for commercial and industrial purposes. The chemical profile of the essential oils was evaluated by GC-FID and GC-MS, and the results were assessed through multivariate analyses. The data showed that the time of day and seasonal variations affect the quality of the essential oil obtained. Leaves harvested at the end of the day (5:00 pm) in the dry season resulted in richer essential oils with higher amounts of non-oxygenated sesquiterpenes. To the best of our knowledge, environmental conditions induce metabolic responses in the leaves of C. langsdorffii, which changes the patterns of sesquiterpene production. Therefore, these factors need to be considered to obtain better concentrations of bioactive compounds for pharmacological studies. © 2016 de Almeida et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Resende E.C.O.,Agronomic Institute | Martins P.F.,University of Sao Paulo | de Azevedo R.A.,University of Sao Paulo | Jacomino A.P.,University of Sao Paulo | Bron I.U.,Agronomic Institute
Brazilian Journal of Plant Physiology | Year: 2012

'Golden' papayas at maturity stage 1 (15% yellow skin) were chosen to study selected oxidative processes, the activity of antioxidant enzymes and lipid peroxidation in storage at 22°C, during the ripening of the fruit. An increase in ethylene production was observed on the second day of storage and it was followed by an increase in respiration. An increased activity of catalase, glutathione reductase and ascorbate peroxidase was observed concurrently or soon after this increase in ethylene production and respiration. The increased activity of these enzymes near the peaks of ethylene production and respiration is related to the production of oxidants accompanying the onset of ripening. On the fourth day of storage, there was an increased lipid peroxidation and decreased activities of catalase, glutathione reductase and superoxide dismutase. Lipid peroxidation induces the increase of antioxidant enzymes, which can be verified by further increases in the activities of catalase, glutathione reductase, superoxide dismutase and ascorbate peroxidase. Unlike the other antioxidant enzymes, the ascorbate peroxidase activity in the pulp increased continuously during ripening, suggesting its important role in combating reactive oxygen species during papaya ripening. With regard to physical-chemical characteristics, the soluble solids did not vary significantly, the acidity and ascorbic acid contents increased, and hue angle and firmness decreased during storage. The results revealed that there was variation in the activity of antioxidant enzymes, with peaks of lipid peroxidation during the ripening of 'Golden' papaya. These results provide a basis for future research, especially with regard to the relationships among the climacteric stage, the activation of antioxidant enzymes and the role of ascorbate peroxidase in papaya ripening. Source

De Oliveira Portella R.,Sao Paulo State University | Facanali R.,Agronomic Institute | Marques M.O.M.,Agronomic Institute | Rolim De Almeida L.F.,Sao Paulo State University
Natural Product Research | Year: 2015

GC/FID and GC-MS analysis revealed germacrene D, bicyclogermacrene, α-cadinol and cubenol as major compounds from aril. Germacrene D, bicyclogermacrene, trans-caryophyllene and δ-elemene are major compounds in fruits. Germacrene D, spathulenol, trans-caryophyllene and caryophyllene oxide are major compounds in leaves. Furthermore, multivariate analysis revealed distinct groups between the composition of essential oils from aril and fruit, when compared with terpene production found in leaves. Lipid composition found in arils could be protected by the presence of non-oxygenated sesquiterpenes, as germacrene D and bicyclogermacrene. Chemical profiles of essential oils from the fruits, arils and leaves of Copaifera langsdorffii Desf. revealed different compositions, which could be related to environmental pressures. Thereby, non-oxygenated sesquiterpenes can also work against herbivory, pathogens and predator's attack, emphasising the importance of further studies among terpenes, ecology interactions and plant physiology. © 2015 Taylor & Francis. Source

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