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121.
Simone TelesJosé Alberto Pereira Carlos H.B. SantosRenata V. Menezes Ricardo MalheiroAngélica M. Lucchese Franceli Silva 《Industrial Crops and Products》2012,37(1):247-252
Lippia alba (Mill.) N.E. Brown, the ginger grass, is a medicinal and aromatic plant widely used in Latin America. In this work the effect of the geographical origin and different drying methodologies on L. alba leaves production, essential oil content and composition were evaluated. Field experiments were conducted in three different municipalities (Amargosa, Cruz das Almas and Santo Antônio de Jesus) from Bahia region (Brazil) and two drying methodologies (traditional and artificial with controlled conditions) were assessed. Fresh and dried leaves essential oils were extracted by hydro-distillation and their volatiles were determined by gas chromatography.The geographical origin affected the mass production, essential oil content and both qualitative and quantitative fractions of their composition. Leaves from Cruz das Almas had higher yield in essential oil content. Overall, 26 oil constituents were identified. Carvone, germacrene D and limonene were the main oil constituents. The drying methodologies combined with the geographic origin influenced essential oil composition showing that L. alba constituents were influenced by post-harvest treatments. Some constituents were sensitive to both methods applied, while some enhanced their content like germacrene D. 相似文献
122.
Márcia Regina Fagundes-Klen Márcia Teresinha Veit Carlos Eduardo Borba Rosangela Bergamasco Luiz Gustavo de Lima Vaz Edson Antonio da Silva 《Water, air, and soil pollution》2010,213(1-4):15-26
Copper biosorption onto chemically modified biomass of marine alga Sargassum filipendula was investigated in a batch reactor and a fixed bed column. Experiments were carried out in the batch reactor to obtain kinetic and equilibrium data and to assess the copper desorption efficiency of different eluent solutions. The pseudo-first-order, pseudo-second-order, and Langmuir kinetic models were used to correlate kinetic data. The experimental data fitted well to the pseudo first order and Langmuir kinetic models. Langmuir and Freundlich models were applied to describe the equilibrium data obtained at a fixed temperature of 30°C and at pH values of 3.0, 4.0, 5.0, and 6.0. The maximum capacities of copper biosorption onto the algal biomass were 1.43, 1.59, 2.40, and 2.36 mequiv./g at pH 3.0, 4.0, 5.0, and 6.0, respectively. The efficiencies of two eluent solutions (calcium chloride and hydrochloric acid) for copper removal from the biomass were evaluated at different concentrations (0.1, 0.2, 0.5, and 1.0 mol/L). The efficiencies of the calcium chloride solutions varied from 1% to 14%, while efficiencies varying from 95% to 99% were obtained when hydrochloric acid solutions were applied. Three adsorption/desorption cycles were carried out in a fixed bed column using 0.1 mol/L hydrochloric acid as eluent solution. The results showed that an increase in the number of cycles led to a reduction in the adsorption capacity of the alga. The desorbed copper fraction presented no significant variation, remaining around 63% in the three adsorption/desorption cycles. 相似文献
123.
Bentonite-humic acid improves soil organic carbon,microbial biomass,enzyme activities and grain quality in a sandy soil cropped to maize (Zea mays L.) in a semi-arid region 下载免费PDF全文
ZHOU Lei XU Sheng-tao Carlos M.MONREAL Neil B.MCLAUGHLIN ZHAO Bao-ping LIU Jing-hui HAO Guo-cheng 《农业科学学报》2022,21(1):208-221
A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effect on soil physicochemical and biological properties, and grain quality is largely unknown. The effect of B-HA, added at 30 Mg ha-1, was studied at 1,3, 5 and 7 years after its addition to a degraded sandy soil in a semi-arid region of China. The addition of B-HA significantly increa... 相似文献
124.
Henrique de Souza Luche José Antonio Gonzalez da Silva Rafael Nornberg Emilio Ghisleni Arenhardt Vanderlei da Rosa Caetano Luciano Carlos da Maia Antonio Costa de Oliveira 《Journal of Crop Science and Biotechnology》2017,20(2):73-80
In wheat, the increase of yield and stability associated traits can be achieved by combining parents containing the stay-green trait and favorable alleles for grain yield. The aim of this work was to analyze the genetic dissimilarity between wheat lines from stay-green and synchronized maturation groups and elite cultivars. Moreover, to propose promising combinations seeking the selection of high-grain yield and high bread-making quality genotypes containing stay-green trait. The experiment was conducted in a randomized block design with three replications in 2003, 2004, and 2005, using sister-lines with the presence and absence of stay-green trait and elite cultivars. Genetic variability exists among wheat strains from the synchronized stay-green maturation group and elite cultivars. Genotypes of maturation group stay-green obtained an average performance superior to the synchronized group. Crosses between stay-green lines and the CEP 29 and BRS 177 cultivars are promising in the selection of genotypes carrying the stay-green trait with high yield and bread-making quality. 相似文献
125.
Carlos Renato Ramos-Palacios Ernesto I. Badano Joel Flores Jorge A. Flores-Cano José L. Flores-Flores 《European Journal of Forest Research》2014,133(3):391-404
Forest fragmentation affects seed production, but little is known about how seeds are distributed in fragmented forests after primary dispersion and how this affects their interactions with other organisms. This study addressed these issues in a fragmented oak forest of Quercus laeta where four habitat types were recognized: interior and edge of patches, deforested matrix around patches, and an abandoned field. Areas and distances to the abandoned field were measured for 40 patches, and acorns were sampled in all habitats. Only samples from the interior and edge of patches had acorns, which were classified as aborted, viable, and parasitized by insects or fungi. Acorns in all these classes were regressed against patch area and distance to the abandoned field. Field experiments were also conducted to determine whether acorn removal rates varied across habitats. Aborted acorns within patches were not related to area or distance, but they decreased with increasing values of both variables at patch edges. Within patches, viable acorns were positively related to increases in area and distance, while the converse occurred for insect-damaged acorns; fungal-infested acorns were not related to patch variables in this habitat. Complex interactions between area and distance explained how acorns in these classes were distributed across patch edges. Acorn removal was higher within patches and their edges when compared to human-disturbed habitats; both mice and birds were identified as potential acorn dispersers. These results suggest that forest fragmentation affects acorn-mediated processes and that this may influence the recovery of patch connectivity in the landscape. 相似文献
126.
Robson Elpídio Pereira Ribeiro Alexandre Carneiro Leão de Mello Márcio Vieira da Cunha Suellen Brandão de Miranda Costa Janerson José Coelho Rayanne Thalita de Almeida de Souza Mércia Virginia Ferreira dos Santos 《Grass and Forage Science》2023,78(1):194-203
This study hypothesised that different elephant grass genotypes respond differently in terms of their morphological development to irrigation. The objective of this study was to evaluate how water availability could affect the morphological development of different genotypes of elephant grass. The treatments consisted of four genotypes of elephant grass [Cenchrus purpureus (Schumach.) Morrone], managed under irrigation or not, during a two-year field trial. The experiment was arranged in a randomised block design in a split-plot, with four replicates per treatment (n = 4). Between the genotypes, two of them were classified as tall-sized (IRI 381 and Elephant B), and two as dwarfs (Taiwan A-146 2.37 and Mott). A three-way interaction between season, irrigation, and genotype affected the variables plant height, stem diameter, number of dead tillers, light interception (LI), and leaf area index (LAI) (p < .05). The morphological development of all genotypes was negatively impacted by the dry season. All genotypes grew taller during the rainy season (p < .05) and had a greater light interception (62%–80%) compared to the dry period (28%–59%). The genotype Mott, showed comparable LI and LAI to the tall-sized genotypes, whilst Taiwan A-146 2.37 was characterized by the lowest values, despite being the genotype with the greatest tiller density (60 tillers m−2) (p < .05). The use of irrigation mitigated the negative effects of the dry season on the plants, however, the type and size (tall vs. dwarf) of the elephant grass genotypes defined the extent of the responses to the use of the irrigation during the dry period. 相似文献
127.
128.
Pablo A. Conejeros Carlos Calderón Daniela Gómez Luis Nilo Sergio H. Marshall 《Aquaculture International》2011,19(5):999-1005
As with any other intensively farmed animal species, the Atlantic salmon has been selectively bred and cross-bred to maximize
desirable traits. Selection tends to diminish genetic diversity in target populations, which among other negative effects
is hypothesized to decrease their capacity to confront a broad variety of pathogens. We have analyzed mitochondrial (mtDNA)
as well as major histocompatibility complex (MHC) DNA sequences from individuals collected from a single aquaculture cage
in southern Chile. Interestingly, only two mtDNA haplotypes were obtained; however, several different MH alleles were detected,
with divergence values that were compared with those of natural populations of salmonids. Thus, it seems evolutionary processes
responsible of keeping MH diversity in the wild managed to retain MH variability in farmed Atlantic salmon, maintaining high
immune diversity despite the generally lower levels of observed neutral genetic diversity. 相似文献
129.
Wilson Wagner Ribeiro Teixeira Rafael Battisti Paulo Cesar Sentelhas Milton Ferreira de Moraes Adilson de Oliveira Junior 《Journal of Agronomy and Crop Science》2019,205(5):533-544
Soya bean yield gap can be caused by different factors resulting in uncertainties when the objective is to use such information for farm decision‐making and reference yield determination. Thus, this study aimed to quantify the soya bean yield gap for four sites, located in Southern and Midwestern Brazil, as well as the uncertainties of that related to cultivars, sowing dates, soil types and reference yields. The crop simulation model DSSAT‐CSM‐CROPGRO‐Soybean was calibrated for cultivars with similar maturity groups, based on the data obtained from the best farmers at the county level. The yield gap by water deficit (YGWD) was obtained through the difference between potential and attainable yields, and that one caused by sub‐optimum crop management (YGCM) by subtracting actual yield of each county, obtained from official statistics between 1989/90 and 2014/15 growing seasons, from the estimated attainable yield. The yield was simulated using four sowing dates, three soil types and two soya bean maturity groups by county. The reference yield uncertainty was quantified using yield reference from crop model and regional winners of the soya bean yield context, conducted by CESB (Brazilian Soybean Strategic Committee), for the growing seasons from 2013/14 to 2015/16. The crop model showed a good agreement between measured and simulated crop development and growth using calibration by maturity group, with low root mean square error (347 kg/ha). Southern sites had a mean YGWD of 1,047 kg/ha, while in the Midwest, it was lower than 100 kg/ha. The YGCM was 1,067, 528, 984 and 848 kg/ha, respectively, for Castro, PR, Mamborê, PR, Montividiu, GO and Primavera do Leste, MT, representing the opportunity for yield gain when having the best farmers as reference. The maturity groups, sowing dates and soil types showed to be an important source of uncertainty for yield gap determination, being recommended to investigate the farms in detail for an appropriate quantification. The reference yield showed expressive uncertainties, with some farmers presenting conditions to increase their soya bean yields by more than 3,000 kg/ha, when considering as reference the yields obtained by the winners’ farmers. These results show that uncertainties must be reduced when assessing farm yield gaps, in order to ensure that expected rate of soya bean yield growth could be reached by adopting the same technologies from CESB winners and best farmers in the county as a reference. 相似文献
130.
Ahmed Ibrahem I. Badawy Kathleen Lutz Anja Taubert Horst Zahner Carlos Hermosilla 《Veterinary research communications》2010,34(2):103-118
Host immune responses conducted against antigens of Eimeria bovis are key factors for the development of protective immunity against this protozoan disease. In this study we investigated
the expression of E. bovis-derived antigens on the host cell surface membrane during E. bovis first merogony in vitro. Host cells carrying E. bovis-meront I stages expressed E. bovis host cell surface antigens (EbHCSAg) on their surface membrane which were recognised by hyperimmune sera of calves and by
sera from rats immunized with E. bovis merozoites I, when tested by indirect immune fluorescent antibody test (IIFAT), laser scanning confocal microscopy (LSCM)
and immune electron microscopy. Expression of EbHCSAg on permissive host cells was earliest detected 7 days p. i., thus coinciding
with the onset of the parasite replication. Membrane-associated EbHCSAg were removed from infected host cells by proteinase
K, partially by Triton X-100, Triton X-114 and Triton X-405, but not by 1 M NaCl, CHAPS or phospholipase C treatment. Antibodies,
affinity-purified on paraformaldehyde/glutardialdehyde (PAGA)-fixed E. bovis meront I-infected bovine host cells bound to the surface meront I-carrying cells and to merozoites I (IIFAT, LSCM) but, in
contrast to untreated sera, not to sporozoites. When tested on methanol-fixed merozoites I and sporozoites by IIFAT, affinity-purified
antibodies bound to structures in the apical complex area of merozoites I, but not to sporozoites, whilst untreated sera caused
diffuse labelling of internal structures of both parasite stages. Immune electron microscopy demonstrated binding of affinity-purified
antibodies to micronemes and dense granules of merozoites I. Although the function of EbHCSAg is still unknown, results of
this study might suggest an involvement in the development of protective immunity against E. bovis infections. 相似文献