Effects of fishing protection on the genetic structure of fish populations     

Ángel Pérez-Ruzafa  Mercedes González-Wangüemert  Concepción Marcos 《Biological conservation》2006,129(2):244-255

Marine reserves have been identified as an important tool in the management of fishery resources and their number is increasing rapidly, most of them being on islands. However, knowledge on the real effect of protection from fishing on the genetic structure of populations, the spatial scales involved, or the suitability of islands as reserves in terms of connectivity, is scarce. This paper analyses the effects of fishery protection on the genetic structure of populations of Diplodus sargus, a target species, in protected and non-protected areas of the western Mediterranean. Populations studied showed high genetic variability at spatial scales from 10¹ to 10³ km. Protected areas have significantly higher allelic richness. The lower levels of heterozygosis and higher heterozygote deficit showed by islands compared with coastal areas makes clear the importance of considering the connectivity processes when designing a MPA.  相似文献   

Distribution and storage characterization of soil solution for drip irrigation   总被引：1，自引：1，他引：0  

Claudinei F. Souza  Marcos V. Folegatti  Dani Or 《Irrigation Science》2009,27(4):277-288

The increased use of marginal quality water with drip irrigation requires sound fertigation practices that reconcile environmental concerns with viable crop production objectives. We conducted experiments to characterize dynamics and patterns of soil solution within wet bulb formed by drip irrigation. Time-domain reflectometry probes were used to monitor the distribution of potassium nitrate (KNO₃) and water distribution from drippers discharging at constant flow rates of 2, 4 and 8 L h⁻¹ in soil-filled containers. Considering results from different profiles, we observed greater solute storage near the dripper decreasing gradually towards the wetting front. About half of the applied KNO₃ solution (48%) was stored in the first layer (0–0.10 m) for all experiments, 29% was stored in the next layer (0.10–0.20 m). Comparing different dripper flow rates, we observed higher solution storage for 4 L h⁻¹, with 45, 53 and 47% of applied KNO₃ solution accumulating in the first layer (0–0.10 m) for dripper flow rates of 2, 4 and 8 L h⁻¹, respectively. The results suggest that based on the volume and frequency used in this experiment, it would be advantageous to apply small amounts of solution at more frequent intervals to reduce deep percolation losses of applied water and solutes.  相似文献   

Upland rice breeding in Brazil: a simultaneous genotypic evaluation of stability, adaptability and grain yield     

José Manoel Colombari Filho  Marcos Deon Vilela de Resende  Orlando Peixoto de Morais  Adriano Pereira de Castro  Élcio Perpétuo Guimarães  José Almeida Pereira  Marley Marico Utumi  Flávio Breseghello 《Euphytica》2013,190(1):117-129

A durum wheat recombinant inbred line population developed from PDW 233 × Bhalegaon 4 cross was analyzed in five environments to understand the genetic network responsible for test weight (TW), thousand kernel weight (TKW), grain yield (YLD), spike length (SL), spikelets per spike (SPS), kernels per spike (KER) and kernel weight per spike (KWS). Genotype, environment and their interactions were main sources of variance for all the traits. TW and TKW were influenced by 11 main effect QTL and 6 digenic epistatic interactions detected on chromosomes 2A, 2B, 4B and 7A. Grain yield was influenced by three epistatic interactions and five main effect QTL, of which two on chromosome 2A were most consistent. A major QTL for spike length was observed on chromosome 3B. QTL for spike characters were distributed over 9 chromosomes. All the traits showed significant influence of digenic epistasis (QQ) and, to a certain extent, QTL × environment interactions (QQE). Therefore, while breeding for complex traits like kernel characters and grain yield components, these interactions should also be considered important. The consistent QTL on chromosome 2A between the marker interval Xgwm71.2–Xubc835.4 with pleiotropic effect on TW and TKW, may be utilized in early generation selection to improve TW and TKW and thereby the milling potential of the durum wheat.  相似文献   

Esophageal varices in dogs: A retrospective case series     

Tanner S. Slead  Christine L. Gremillion  Eli B. Cohen  M. Katherine Tolbert 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(2):493

BackgroundEsophageal varices (EV) are abnormally dilated veins in the esophagus caused by alterations of blood flow or pressure. Esophageal variceal hemorrhage is a major complication of hepatic disease in humans, but a lack of information exists regarding associated adverse events in dogs.ObjectiveTo describe the clinical manifestations and associated etiologies and outcomes of dogs with EV.AnimalsTwenty‐five client‐owned dogs with EV diagnosed via computed tomography (CT), endoscopy, or fluoroscopy.MethodsRetrospective case series. Cases were identified by review of the hospital imaging records database between 2010 and 2020. Signalment, clinical signs, and outcomes were documented. When present, additional collateral vasculature was also recorded. Cases were subcategorized into suspected etiology based upon the anatomic location or absence of an attributable underlying disease process, as well as the direction of blood flow.ResultsTwenty‐four of 25 cases were identified via CT, with a prevalence of 0.012% (24/1950 total studies). Presenting clinical signs were nonspecific, and more likely because of the underlying cause as opposed to complications secondary to EV themselves. Etiologic anatomic locations were similar in occurrence between the abdomen (N = 14) and thorax (N = 11). All cases with an abdominal etiologic location had presumed or confirmed portal hypertension and 9/11 cases with a thoracic etiologic location had pulmonary, caval, or systemic hypertension. No cases died or were euthanized as a direct result of EV or associated hemorrhage.Conclusions and Clinical ImportanceEsophageal varices are rarely reported in dogs and commonly identified concurrently with portal, pulmonary, and caval hypertension. Hemorrhage is not a common clinical manifestation of EV.  相似文献   

Population structure of the critically endangered Brazilian guitarfish Pseudobatos horkelii (Rhinobatidae) revealed by double-digest restriction site-associated DNA sequencing     

Yan Torres  Matheus Marcos Rotundo  Marcelo Vianna  Patricia Charvet  Vicente Vieira Faria  Claudio Oliveira  Fausto Foresti  Vanessa Paes Cruz 《水产资源保护:海洋与淡水生态系统》2024,34(1):e4035

Genetic variation and phylogenetic relationships based on RAPD analysis in section Caulorrhizae, genus Arachis (Leguminosae)     

Marcos Aparecido Gimenes  Catalina Romero Lopes  Maria Leticia Galgaro  José Francisco Montenegro Valls  Gary Kochert 《Euphytica》2000,116(3):187-195

Wild Arachis germplasm includes potential forage species, such as the rhizomatous Arachis glabrata and the stoloniferous A. pinto and A. repens. Commercial cultivars of A. pintoi have already been released in Australia and in several Latin American countries, and most of these cultivars were derived from a single accession of A. pintoi (GK 12787). Arachis repens is less productive as a forage plant than is A. pintoi. However, it can be crossed with A. pintoi, and thus has good potential as germplasm for the improvement of A. pintoi. Arachis repens is also used as an ornamental plant and ground cover. Many new accessions of these two stoloniferous species are now available, and they harbor significant genetic variability beyond that available in the few older accessions, previously available. Therefore, these new accessions need to be conserved, documented and considered in terms of their potential for crop improvement and direct commercial use. Sixty-four accessions of this new germplasm were analyzed using RAPD analysis. Most of the accessions of A. repens grouped together into a clearly distinct group. In general, the accessions from the distinct valleys of the Jequitinhonha, São Francisco and Paranã rivers did not group together, suggesting there is not a tight relation between dispersion by rivers and the geographic distribution of genetic variation in these species.  相似文献   

Data on the aetiology of swine atrophic rhinitis. V. The role of genetic factors.     

B Eliás  D Hámori 《Acta veterinaria Academiae Scientiarum Hungaricae》1976,26(1):13-19

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The differentiation of Bordetella bronchiseptica strains. 5. Virulence factors in relation to phase changes in Bordetella bronchiseptica strains     

B Eliás  M Krüger 《Archiv fuer experimentelle veterinaermedizin》1988,42(6):859-866

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Thiophanate-methyl sensitivity and fitness in Lasiodiplodia theobromae populations from papaya in Brazil     

Rômulo Diniz Cavalcante  Waléria Guerreiro Lima  Ricardo Brainer Martins  Juan Manuel Tovar-Pedraza  Sami Jorge Michereff  Marcos Paz Saraiva Câmara 《European journal of plant pathology / European Foundation for Plant Pathology》2014,140(2):251-259

Stem-end rot, caused by Lasiodiplodia theobromae, is an important postharvest disease of papaya in Brazil. The use of fungicides is one of the main disease management measures. However, there are no data available on the sensitivity of L. theobromae to thiophanate methyl (methyl benzimidazole carbamate), the most common fungicide used in papaya orchards in northeastern Brazil. Thus, the effective concentration that results in 50 % of mycelial growth inhibition (EC₅₀) of 109 isolates, representing five populations of the pathogen was estimated in vitro. Seven components of fitness were measured for the 10 isolates with lower and high values of EC₅₀. Of the 109 isolates, 20.2 % were resistant to the fungicide with EC₅₀ values greater than 300 μg ml^?1, whereas the remaining 79.8 % were sensitive with an average EC₅₀ of 1.87 μg ml^?1. The EC₅₀ values for the resistant isolates were significantly (P?≤?0.05) higher than those for the sensitive isolates. When the fitness components were evaluated, only in relation to the spore production was significant difference among sensitive and resistant isolates, and resistant isolates showed sporulation capacity significantly lower than the S isolates, indicating a fitness cost.  相似文献   

Generation of reactive oxygen species by leukocytes of Prochilodus lineatus     

Marcos Tucunduva de Faria  Maria Fernanda Cury-Boaventura  Lucia Rossetti Lopes  José Roberto Machado Cunha da Silva 《Fish physiology and biochemistry》2014,40(2):445-455

Prochilodus lineatus (curimbatá), from the Procholodontidae family, is a Brazilian freshwater fish, which is important commercially, nutritionally and ecologically. It is encountered in the Rio da Prata Bay in Southern South America. Studies on the immune system of this fish are scarce, but the physiological mechanisms of the species are analogous to those of other vertebrates. Thus, this work discusses the present study, which correlates P. lineatus leukocytes and the generation of reactive oxygen species after modulatory stimuli. Leukocytes were characterized by light and electron transmission microscopy and investigated by the generation of H₂O₂ and O₂ ^?, using phenol red, flow-cytometry and electron transmission histochemistry. The study determined that monocytes and neutrophils are the main cells responsible for generating O₂ after stimulation with phorbol myristate acetate. Superoxide dismutase successfully inhibited the generation of reactive oxygen species in neutrophils and monocytes, but stimulated generation when in association with phorbol myristate acetate. Fish leukocyte samples from P. lineatus showed cross-reactivity with antibodies directed against human NADPH-oxidase antibody subunits (p47^phox and p67^phox). Thus, catalase enhanced the presence of p47^phox. Neutrophil mitochondria were shown to be generators of H₂O₂ (charged by cerium precipitate), being enlarged and changing their format. The present study contributes to a better understanding of the respiratory burst pathways in this species and suggests mitochondria as the organelle responsible for generation of reactive oxygen species.  相似文献