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991.
Mírian Peixoto Soares da Silva Marta Simone Mendonça Freitas Paulo Cesar Santos Almy Junior Cordeiro de Carvalho Tiago Silva Jorge 《Journal of plant nutrition》2019,42(5):417-427
This study aims to describe macronutrient and boron deficiencies in pepper grown in a hydroponic system in the presence of a substrate during the vegetative and fruiting phases. The experiments were carried out into a greenhouse, and consisted of a randomized block design with eight treatments: complete solution (control) and nitrogen (-N), phosphorus (-P), potassium (-K), calcium (-Ca), magnesium (-Mg), sulfur (-S) and boron (-B) deficient solutions, with four repetitions for each assay. Visual diagnoses of certain macronutrient and boron deficiencies can be applied by farmers to aid in soil management, since they are observed in leaves, while N, P, Ca, S and B deficiencies led to roots symptoms. Pepper fruits showed nutritional deficiency symptoms when grown under N, K, Ca, Mg, S and B deficits. The appearance of nutrient deficiency symptoms in pepper plants occurs in the following order: N, K, P, Mg, S, Ca and B. 相似文献
992.
Carine de Freitas Souza Cristine Rampelotto Bruno Bianchi Loureiro Fernanda Alves Pereira Adriane Erbice Bianchini Carine Dahl Corcini Antonio Sergio Varela Junior Tatiana Emanuelli Leila Picolli da Silva Sílvio Teixeira da Costa Kalyne Bertolin Monique Tomazele Rovani Paulo Bayard Dias Gonçalves Berta Maria Heinzmann Bernardo Baldisserotto 《Fish physiology and biochemistry》2018,44(4):1253-1264
In aquaculture, nutrition and supplemented diets have been shown to affect broodstock reproductive performance. In this study, we investigated the effects of dietary supplementation with Cymbopogon flexuosus essential oil (CFEO) microcapsules on reproductive-related parameters in silver catfish (Rhamdia quelen) male broodfish. Adult male broodstocks were separated into three groups according to the concentrations of supplemented CFEO (0.0?=?control; 1.0 or 3.0 mL per kg of diet). After 20 days under experimental conditions, the animals were euthanized and the gonads were harvested for gonadosomatic index, sperm analysis, oxidative stress, and histopathology; testosterone levels were measured in the plasma; gene expression of prl, smtl, pomca, and pomcb was assessed in the pituitary gland by real-time PCR. The results showed no alterations on reproductive parameters in R. quelen males treated with Cymbopogon flexuosus essential oil compared to the control-diet animals. In conclusion, CFEO microcapsules supplied for 20 days in the concentrations of 1.00 or 3.00 mL per kilogram of diet did not affect the reproduction criteria evaluated in this study in male silver catfish. 相似文献
993.
994.
Bárbara Machado Campos Adriana Santana do Carmo Andrea Alves do Egito Arthur Silva da Mariante Maria Socorro Muaés do Albuquerque João José Simoni de Gouveia Carlos Henrique Mendes Malhado Lucas Lima Verardo Marcos Vinícius Gualberto Barbosa da Silva Paulo Luiz Souza Carneiro 《Tropical animal health and production》2017,49(8):1677-1684
Genetic diversity is one of the most important issues in studies on conservation of cattle breeds and endangered species. The objective of this study was to estimate the levels of genetic differentiation between locally adapted taurine (Bos taurus taurus) and zebu (Bos taurus indicus) breeds in Brazil, which were genotyped for more than 777,000 SNPs. The fixation index (F ST), principal component analysis (PCA), and Bayesian clustering were estimated. The F ST highlighted genetic differentiation between taurine and zebu breeds. The taurine lines, Caracu and Caracu Caldeano, had significant genetic differentiation (F ST close to 5%) despite their recent selection for different uses (meat and milk). This genetic variability can be used for conservation of locally adapted animals, as well as for breeding programs on zebu breeds. Introgression of zebu in locally adapted breeds was identified, especially in Curraleiro Pé-Duro breed. The Gyr breed, however, had low breed purity at genomic level due to its very heterogeneous mixing pattern. 相似文献
995.
The objective of this study was to compare the different methods of detecting Toxoplasma gondii in sheep tissue, tested serologically positive by the indirect immunofluorescent antibody test (IFAT). Brain, diaphragm, and blood samples were collected from 522 sheep slaughtered at the S?o Manuel abattoir, S?o Paulo State, Brazil. Brain and diaphragm samples from IFAT seropositive animals were digested by both trypsin and pepsin and then injected into mice. Part of the digested samples was used to prepare slides for Giemsa staining and in the polymerase chain reaction (PCR). Tissue fragments were fixed in formalin and examined using hematoxilin-eosin (HE). Forty of the sheep (7.7%) were IFAT positive. T. gondii was isolated in 23 (59.0%) of the 39 mice with pepsin-digested brain samples and in 27 (69.0%) of the 39 with trypsin-digested brain samples. Injection of diaphragm samples led to T. gondii isolation in 26 (66.7%) of the 39 pepsin-digested samples and 21 (53.8%) of the 39 trypsin-digested samples. Cytological and hystopathological examination of both brains and diaphragms was negative in all examined sheep. PCR was positive in 7 (17.9%) of the trypsin and 2 (5.1%) of the pepsin-digested samples, while 9 (23.1%) of the trypsin and 3 (7.7%) of the pepsin-digested samples showed T. gondii DNA. T. gondii isolation rate in mice (n = 34; 85.0%) was significantly higher than detection by PCR (n = 15; 37.5%). 相似文献
996.
Lucas Silva Azevedo Incio Abreu Pestana Marcelo Gomes Almeida Wanderley Rodrigues Bastos Cristina Maria Magalhes Souza 《Ecology of Freshwater Fish》2022,31(1):72-80
Floodplain lakes are ecosystems characterised by annual flood and dry cycles. Fish ecology is influenced by the flood pulse due to the large influx of allochthonous food resources and diversification of habitats during the flood cycle, while during the dry cycle, fishes tend to be confined in reduced habitat. The aim of this study was to evaluate the seasonal variation in trophic niche width and overlap of four species—Mylossoma duriventre, Prochilodus nigricans, Cichla.pleiozona and Serrasalmus rhombeus—in an Amazonian floodplain lake. Stable isotope analyses were used to estimate trophic niche width and overlap during the flood and dry seasons. We hypothesised broader niche width for all species during the flood cycle and a higher degree of overlap between the two piscivorous fishes during the dry cycle. Isotopic niche width was 72% broader for P. nigricans, 61% for S. rhombeus and 54% for C. pleiozona during the dry cycle, which did not support our hypothesis. Core niche width overlaps were not observed between piscivorous species in either flood or dry cycle. The results indicate that seasonal variation in isotopic niche width is specific to feeding habit. Understanding how fish trophic ecology responds to changes in the hydrological regime during the seasons is crucial for sustainable fishery management in a region where many people rely heavily on fish for nutritional and economic purposes. 相似文献
997.
Brenna de Sousa Barbosa Herlon Victor Rodrigues Silva Beatriz Evaristo de Almeida Tabosa Thalles Gothardo Pereira Nunes Francisco Felipe de Magalhes Lúcia Daniel Machado da Silva 《Reproduction in domestic animals》2019,54(12):1630-1636
Sperm morphometry is the tool that confers objectivity to the morphological evaluation by accurately measuring the dimensions of the gamete and its structures. Thus, the aim of the study was to perform a morphometric characterization of the domestic cat sperm. Therefore, sperm samples were collected from twenty pairs of epididymis in a TRIS extender at 37ºC. An aliquot of the sample was used to make a smear with Rose Bengal solution, and afterwards, the morphology and morphometry were analysed. In the morphology, were quantified the percentage of normal sperm cells, morphological changes of head, midpiece and tail. In morphometry, each normal sperm cell was measured for length, width, area and perimeter of head and midpiece, tail length and total length. The parameters ellipticity, elongation, regularity and rugosity were also determined. The percentage of normal sperm was 67.21%. Of the abnormalities, the curled/folded tail, followed by the curved midpiece, abnormal shaped head and detached head were the most quantified. The sperm head presented 5.56 ± 0.01 μm and 3.10 ± 0.01 μm of length and width, respectively. The head area was 16.94 ± 0.05 μm2, while the perimeter was 16.16 ± 0.03 μm. In the derived parameters, the values were as follows: ellipticity of 1.81 ± 0.00; elongation of 21.39 ± 0.12; regularity of 0.81 ± 0.00; and rugosity of 0.14 ± 0.00. The midpiece presented length and width of 7.96 ± 0.01 μm and 0.76 ± 0.01 μm, respectively. The mean length of the sperm tail was 45.12 ± 0.06 μm, and the total cell size was 58.67 ± 0.06 μm. Thus, it was concluded that the cat sperm is an elongated cell, with high rugosity and regularity. The spermatic tail represents more than ¾ of the total length of the cell and the midpiece exceeds the length of the head. 相似文献
998.
Lucas Pecci Canisares Maurício Roberto Cherubin Laura Fernanda Simoes da Silva Andre Luiz Custodio Franco Miguel Cooper Sacha J. Mooney Carlos Eduardo Pellegrino Cerri 《Soil Use and Management》2020,36(2):189-199
Land use change (LUC) alters soil structure and, consequently, the functions and services provided by these soils. Conversion from extensive pasture to sugarcane is one of the largest land transitions in Brazil as a result of the growth of the domestic and global demands of bioenergy. However, the impacts of sugarcane expansion on the soil structure under extensive pasture remains unclear, especially when considering changes at the microscale. We investigated whether LUC for sugarcane cultivation impacted soil microstructure quality. Undisturbed soil samples were taken from two soil layers (0–10 and 10–20 cm) under three contrasting land uses (native vegetation—NV, pasture—PA and sugarcane—SC) in three different locations in the central-southern Brazil. Oriented thin sections (30 μm) were used for micromorphological analysis. The total area of pores decreased following the LUC in the following order: NV > PA > SC in both soil layers. The area of large complex packing pores (>0.01 mm²) also decreased with the LUC sequence: NV>PA>SC. Qualitative and semi-quantitative micromorphological analysis confirmed porosity reduction was driven by the decrease in complex packing pores and that biological features decreased in the same LUC sequence as the quantitative parameters. Therefore, LUC for sugarcane expansion reduced microscale soil porosity, irrespectively of soil type and site-specific conditions, indicating that the adoption of more sustainable management practices is imperative to preserve soil structure and sustain soil functions in Brazilian sugarcane fields. 相似文献
999.
Nicolás Vidal Franco Teixeira de Mello Iván González-Bergonzoni Anahí López-Rodríguez Giancarlo Tesitore Joaquín Pais Samanta Stebniki Ivana Silva Alejandro D’Anatro 《Ecology of Freshwater Fish》2020,29(2):334-345
Unravelling the effect of climate variability on species biology has been one of the main goals of ecological studies. Environmental factors such as river discharge and temperature have being proposed as triggers of reproductive cycle in fish. In temperate climates, fish reproduction is affected mainly by temperature, while is influenced by flood pulses in large tropical rivers. We evaluated the influence of temperature and river discharge as triggers of Iheringichthys labrosus’ reproduction. We studied the following reproductive variables: gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (K). Females of I. labrosus were examined in a time series of ten years along three sites located in Lower Uruguay River at the beginning (last week of November-first week of December, spring) and by the end of the reproductive period (middle-end of April, autumn). Generalised linear models detected a positive effect of mean winter temperature and site on the spring mature female GSI. Site was significant in addition to the interaction between temperature and site. Moreover, the effect of winter temperature was stronger than water discharge in triggering reproductive timing of I. labrosus, contrary to the model proposed for other species in tropical systems. Additionally, a literature review suggested a latitudinal gradient on reproduction, occurring earlier and prolonged with decreasing latitude (and increasing temperature). In this study, we stated the effect of temperature on the life history in a Neotropical fish using a multifaceted approach, particularly important in the current context of global climate warming. 相似文献
1000.
Isabela Ramsdorf Gomes Patinni Cristiane Alves de Andrade Cid Naudi Silva Campos Larissa Pereira Ribeiro Teodoro Sinomar Moreira Andrade Cassiano Garcia Roque Carlos Antônio da Silva Junior Paulo Eduardo Teodoro 《Journal of Agronomy and Crop Science》2020,206(6):806-814
Most of the Brazilian soils, especially in Cerrado biome, have high acidity and toxic aluminium, making the application of limestone an indispensable technique to obtain high yield in soybean crop. The hypothesis of this study was that contrasting base saturation provides changes in water-use efficiency (WUE) and agronomic traits of soybean populations. Thus, we evaluated the WUE and agronomic performance of F3 soybean populations under different base saturation levels. Each experiment was conducted in a randomized complete blocks design with three replicates and 10 F3 populations (P1, P2, P3, P4, P5, P6, P7, P8, P9 and P10) for two crop seasons. Segregating populations were obtained by bulk method. In the first experiment, F3 populations were evaluated without correction of base saturation (V = 30%), while in the second experiment, limestone was applied three months before sowing to increase base saturation to 60%. The traits evaluated were as follows: calcium, magnesium and potassium contents, water-use efficiency (WUE), plant height, first pod height, main stem diameter and grain yield. Our findings indicate that WUE and agronomic performance of F3 soybean populations depends on the saturation condition. We identified the P4 and P9 populations as the most promising for use in breeding programmes aiming at higher tolerance to abiotic stress caused by low base saturation in soil. 相似文献