The Northern Ireland Phytophthora infestans population 1998–2002 characterized by genotypic and phenotypic markers     

L. R. Cooke  D. J. Carlisle  C. Donaghy  M. Quinn  F. M. Perez  K. L. Deahl 《Plant pathology》2006,55(3):320-330

A total of 204 isolates of Phytophthora infestans from Northern Ireland, almost all from commercial potato crops, were collected over 5 years (1998–2002). Phenotypic diversity was assessed using mating type and metalaxyl resistance; genotypic diversity was assessed using two allozyme loci (glucose-6-phosphate isomerase, Gpi, and peptidase, Pep ), mitochondrial DNA haplotype and the multilocus RFLP probe RG57. All isolates were A1 mating type and Gpi 100/100 . The majority were Pep 100/100 , but four Pep 83/100 and six Pep 96/100 isolates were identified. Three mtDNA haplotypes were detected; haplotype IIa was the most common, but each year up to 2001 its frequency declined, with a concomitant increase in Ia isolates. Three isolates had the rare haplotype IIb, but this was only detected in 1998. Metalaxyl resistance and mtDNA haplotype were markedly associated: most haplotype Ia isolates were metalaxyl-resistant, whereas haplotype IIa was more commonly associated with metalaxyl sensitivity. Analysis of a subsample of 91 isolates revealed nine RG57 genotypes, three associated exclusively with haplotype IIa and six exclusively with haplotype Ia. The most common RG57 genotype (51% of isolates) comprised both metalaxyl-resistant and -sensitive haplotype IIa isolates. However, of haplotype Ia isolates, all metalaxyl-resistant phenotypes belonged to one of four RG57 types, one of which was the second most frequent overall (29% of isolates), while all metalaxyl-sensitive isolates belonged to one of two other types. The P. infestans population in Northern Ireland appears to consist of a limited number of clones related to, but differentiated from, the populations in mainland Britain and elsewhere in Europe.  相似文献   

Pregnancy‐Associated Glycoprotein Secretion in North Moroccan Goats     

M Chentouf  B El Amiri  J Sulon  JF Beckers  N Kirschvink  B Boulanouar  JL Bister 《Reproduction in domestic animals》2008,43(6):696-700

The plasma profile of pregnancy‐associated glycoprotein (PAG) and its relationship with fetal number were studied in 14 North Moroccan goats using a semi‐heterologous radioimmunoassay (RIA). Peripheral blood was collected every day during the first month of pregnancy, afterward the blood samples were collected trice a week. The PAG were first detected at day 20 of pregnancy, their levels increase to week 8 of gestation then decrease slightly until parturition. Statistical differences between goats carrying one or two foetuses are observed from week 5 of pregnancy until parturition. Factorial Discriminant Analysis provides mathematical models for the discrimination between the litter size using the PAG level and the week of pregnancy. Using only one blood sample per week, high sensitivity, specificity and overall accuracy (74%, 88% and 81%) were obtained using these models. It is concluded that the PAG RIA is an effective tool for early diagnosis of pregnancy and for discrimination between the litter sizes in North Moroccan goats.  相似文献   

Risk factors associated with Tritrichomonas foetus infection in beef herds in the Province of Buenos Aires, Argentina     

Mardones FO  Perez AM  Martínez A  Carpenter TE 《Veterinary parasitology》2008,153(3-4):231-237

Bovine trichomonosis (BT) is a contagious disease, characterized by reproductive failure, embryonic losses, infertility, and abortions, which directly impacts the reproductive performance of cattle. In this cross-sectional questionnaire-based study, 56 veterinarians provided information on the geographic location and on the demographic, husbandry, and sanitary characteristics of 173 beef herds located in 26 (21%) counties of the Province of Buenos Aires, Argentina. Herds rearing beef cattle (OR=2.5, 95% CI=1.0, 6.3), with low pregnancy rate in cows (相似文献   

Daily rhythms of cortisol and glucose and the influence of the light/dark cycle on anaesthesia in Nile tilapia (Oreochromis niloticus): Does the timing of anaesthetic administration affect the stress response?     

Leandro Santos Costa  Felipe Guedes de Araújo  Renan Rosa Paulino  Luciano Jos Pereira  Edgar Junio Damasceno Rodrigues  Paula Adriane Perez Ribeiro  Priscila Vieira Rosa 《Aquaculture Research》2019,50(9):2371-2379

Although daily variations in drug pharmacokinetics have been reported for a variety of teleost species, the influence of this daily variation on the cortisol response following anaesthesia remains poorly understood. To address this, two experiments were performed. The first experiment described the daily patterns of cortisol and glucose secretion in tilapia (Oreochromis niloticus). The second experiment investigated how the timing of anaesthetic administration (specifically at mid‐light [ML] or at mid‐dark [MD]) affects the induction and recovery times and plasma cortisol and glucose levels of juvenile Nile tilapia exposed to benzocaine, clove oil or tricaine methanesulphonate (MS‐222). The results revealed that the effect on the stress response associated with the moment when anaesthesia took place (ML or MD) varied according to the treatment (p < 0.05). Cortisol levels were significantly higher at ML for MS‐222 (ML = 116.23 ± 25.55; MD = 48.25 ± 22.33 ng/dl) (p < 0.05) and clove oil (ML 59.73 ± 14.27; MD 38.26 ± 12.07 ng/dl) (p < 0.05), whereas no significant differences were found between ML and MD cortisol levels for the control treatment (ML = 72.91 ± 18.42; MD = 64.80 ± 10.68 ng/dl) (p > 0.05) or in the benzocaine‐treated group (ML = 38.7 ± 4.90; MD = 38.60 ± 3.69 ng/dl) (p > 0.05). The highest plasma cortisol level in ML was found in the MS‐222‐treated group. All the tested anaesthetics had similar cortisol levels at MD (p > 0.05).  相似文献   

Dynamic stock model for analysing semi‐intensive production of whiteleg shrimp Litopenaeus (Penaeus) vannamei affected by the acute hepatopancreatic necrosis disease: Assessment of disease severity indicators and relationships with pond water quality parameters     

Nallely Estrada‐Perez  Javier M. J. Ruiz‐Velazco  Francisco J. Magallon‐Barajas  Angel I. Campa‐Cordova  Alfredo Hernndez‐Llamas 《Aquaculture Research》2020,51(1):242-254

The production of Litopenaeus vannamei was analysed when affected by the acute hepatopancreatic necrosis disease using a dynamic stock model and primary data of seven production cycles from a shrimp farm in Mexico from 2013 to 2016. Significant results (p < .05) of the correlation analysis indicated that during those years mortalities by the disease were more severe when water salinity was high and productivity was low. Significant results from ANOVA showed that throughout the period, disease severity and salinity diminished while pond productivity initially declined but subsequently improved. Significant results from regression analyses conducted for each production cycle also indicated the importance of salinity and productivity on disease severity and showed that early mortality by the disease occurred in ponds with warmer water. Within the observed range of water quality parameters, increases of 1 cm in water transparency and 1 g/L in salinity resulted in increments within 0.17%–0.25% and 1.7%–3.1% in shrimp mortality by the disease. When increases of 1°C in water temperature were recorded, outbreaks occurred 0.2–1.57 weeks earlier. In conclusion, the disease strongly determines the dynamics of shrimp production, and the role of salinity, productivity and temperature is worthy of further delving.  相似文献   

The reproductive ecology of exotic Trachemys scripta elegans in an invaded area of southern Europe     

Natividad Perez‐Santigosa  Carmen Díaz‐Paniagua  Judith Hidalgo‐Vila 《水产资源保护:海洋与淡水生态系统》2008,18(7):1302-1310

  相似文献   

Prevalence and risk factors for Trichomonas foetus infection in cattle in northeastern Costa Rica     

Enrique Perez  Patricia A. Conrad  David Hird  Ana Ortuno  Jorge Chacon  Robert BonDurant  Jos Noordhuizen 《Preventive veterinary medicine》1992,14(3-4):155-165

Two studies (one pilot and one cross-sectional) were conducted in the two main livestock-rearing areas of Costa Rica using an improved method (In-Pouch TF) for the detection of Trichomonas foetus infection in bulls. Herd prevalence rates of 6.7% (6/98) and 15.9% (10/63), and bull prevalence rates of 3.9% (6/153) and 6.2% (14/225) were found in the pilot and cross-sectional studies, respectively. Adjusted prevalences in the cross-sectional study were 18.4% and 7.2% for aarms and bulls, respectively. Breed (Bos taurus) and age (over 4 years) were the main risk factors identified using random-effects logistics regression. The nature of the disease and the high prevalence indicated that trichomoniasis could have a serious economic impact on cattle production in Costa Rica.  相似文献   

Effect of Sperm Cryopreservation on the European Eel Sperm Viability and Spermatozoa Morphology     

JF Asturiano  F Marco-Jiménez  DS Peñaranda  DL Garzón  L Pérez  JS Vicente  M Jover 《Reproduction in domestic animals》2007,42(2):162-166

The main objective of the present work was to study the effect of cryopreservation of European eel sperm both on the sperm viability and the spermatozoa head morphology. Spermatozoa morphology was evaluated with computer-assisted morphology analysis after collection in fresh samples, after adding the freezing medium containing dimethyl sulfoxide as cryoprotectant and, finally, after the cryopreservation process and thawing. Cell viability was assessed, in both fresh and thawed samples, by Hoechst 33258 staining. Computer-assisted sperm analysis (CASA) was used to determine the percentage of motile cells and to measure motility parameters in sperm samples. A significant decrease of head perimeter (12.56%) and area (17.90%) was detected from spermatozoa in fresh to thawed samples, indicating that cells do not recover the original size after the cryopreservation process. CASA was used to measure the percentage of motile cells (51.9%) and spermatozoa motility parameters such as curvilinear, straight line and angular path velocities, as well as beating cross frequency. This technique was employed in the fresh sperm samples but proteins present at the freezing medium (L-alpha-phosphatidylcholine) made impossible to use this last technique in thawed samples. When sperm viability was assessed by Hoechst staining, a significant decrease of approximately 15% (73.10 vs 58.26%) of alive spermatozoa was registered from fresh to thawed samples. The percentage of motile cells measured by CASA in fresh samples (51.9%) was lower than the percentage of alive cells determined by Hoechst stainning, suggesting the existence of different batches of spermatozoa in different stages of development, even during the eight to tenth weeks of treatment, when the highest sperm quality was found.  相似文献   

Serum activity/concentration profiles of a sustained-released formulation of sulphathiazole-trimethoprim (2.5:1) in calves     

Sumano H  Gutierrez L  Zamora MA  Perez M  Cruz C 《The Veterinary record》2004,155(21):672-674

Thirty-six two-week-old healthy Holstein-Friesian calves weighing between 52 and 58 kg were divided at random into three groups of 12; group A calves were given a single oral bolus containing 2.5 g sulphathiazole and 1 g trimethoprim in a sustained-release formulation; group B received the same doses of the drugs but the trimethoprim was not in a sustained-release formulation; group C received a bolus containing 2.5 g sulphathiazole and 0.5 g conventional trimethoprim. Blood samples were collected at intervals for two days, the serum was separated and the composite antibacterial activity profiles of the mixture were analysed by an agar-diffusion microbiological method. The mean maximum activities in the serum of the three groups were 23.4 microg/ml in group A, 9.25 microg/ml in group B and 8.01 microg/ml in group C. The mean areas under the curves of the serum activity time curves were 838 microg/ml/hour in group A, 216 microg/ml/hour in group B and 182 microg/ml/hour in group C.  相似文献   

谷子新品种朝谷11号特征特性及高产栽培技术     

孙佳馥  赵术伟 《辽宁农业科学》2000,(4):53-54

朝谷 1 1号由辽宁省水土保持研究所选育 ,于1 997年经辽宁省品种审定委员会审定通过。1 998年被列为省重点农技推广项目 ,计划在 1 998～ 2 0 0 0年在辽宁省朝阳市、阜新市、葫芦岛市的 8县 2区及赤峰市的宁城县推广 6.7万ｈｍ2 。1　朝谷 11号主要特征特性1 .1　农艺性状朝谷 1 1号的叶片、成株茎均为绿色 ,苗期生长快 ,株型紧凑整齐 ,株高 1 65ｃｍ左右 ,穗长 2 3～ 2 5ｃｍ ,单穗粒重 1 4～ 1 6ｇ ,籽粒圆形、黄色 ,出谷率 83%～ 84%,谷草比 1∶1 .3。1 .2　生育期及抗性朝谷 1 1号为中早熟品种 ,生育期 1 0 4～ 1 1 4ｄ ,4月下旬至 5月…  相似文献