Variation among New Zealand isolates of Sphaeropsis sapinea     

S. J. KAY  A. AH CHEE  P. O. SALE  J. T. TAYLOR  E. HADAR  Y. HADAR  R. L. FARRELL 《Forest Pathology》2002,32(2):109-121

Sphaeropsis sapinea is a pathogen of many coniferous species and causes significant losses to the plantation forestry industries of many countries. New Zealand isolates of S. sapinea were examined for colony and morphological characteristics, and pathogenicity to Pinus radiata seedlings. Considerable variation was observed in colony growth form and colour, and in the growth rates on four agar media. The conidial dimensions, carbon and nitrogen utilization, and pathogenicity also varied among the isolates. The variation observed was such that the isolates could not be placed within previously described distinct morphotypes and the present results concur with previous studies cautioning the use of morphological criteria alone to partition the species. These results contrast markedly with previous reports and seemingly indicate a change in the New Zealand S. sapinea population. This difference may reflect the re‐introduction or spread of additional isolates or a shift in the structure of the resident population.  相似文献   

Application of high-resolution melt curve analysis for classification of infectious bronchitis viruses in field specimens     

KA Hewson  GF Browning  JM Devlin  J Ignjatovic  AH Noormohammadi 《Australian veterinary journal》2010,88(10):408-413

Objective A real-time polymerase chain reaction (PCR)/high-resolution melt (HRM) curve analysis protocol was developed in our laboratory to differentiate infectious bronchitis (IB) virus reference strains. In the current study, this method was used to detect and classify IB viruses in field submissions. Procedure Over an 11-month period samples from 40 cases of suspected IB virus were received and 17 submissions were positive for IB virus by polymerase chain reaction. HRM curve analysis classified each strain as subgroup 1, 2 or 3 strain (12 submissions) or a strain that was unable to be classified (5 submissions). The 3′ untranslated region (UTR) and partial S1 gene nucleotide sequences for the 17 IB virus strains were determined and their identity with those of the relative reference strains compared to confirm the classifications generated using the HRM curve analysis. Results Of the 12 IB field viruses classified as subgroup 1, 2, or 3 using HRM curve analysis, the 3′UTR and S1 gene nucleotide sequences had identities ≥99% with the respective subgroup reference strain. Analysis of the 3′ UTR and S1 gene nucleotide sequences for the five IB virus strains that could not be classified indicated that four belonged to one of the subgroups, and one was a potential recombinant strain (between strains from subgroups 2 and 3). A novel recombinant strain was also detected. Conclusion HRM curve analysis can rapidly assign the majority of IB viruses present in field submissions to known subgroups. Importantly, HRM curve analysis also identified variant genotypes that require further investigation.  相似文献   

Rapid changes in flowering time in British plants   总被引：4，自引：0，他引：4  

Fitter AH  Fitter RS 《Science (New York, N.Y.)》2002,296(5573):1689-1691

The average first flowering date of 385 British plant species has advanced by 4.5 days during the past decade compared with the previous four decades: 16% of species flowered significantly earlier in the 1990s than previously, with an average advancement of 15 days in a decade. Ten species (3%) flowered significantly later in the 1990s than previously. These data reveal the strongest biological signal yet of climatic change. Flowering is especially sensitive to the temperature in the previous month, and spring-flowering species are most responsive. However, large interspecific differences in this response will affect both the structure of plant communities and gene flow between species as climate warms. Annuals are more likely to flower early than congeneric perennials, and insect-pollinated species more than wind-pollinated ones.  相似文献   

Comparison of Diverse Differential Plating Methods to Enrich Bovine Spermatogonial Cells          下载免费PDF全文

MI Giassetti  MD Goissis  FRO de Barros  AH Bruno  MEOA Assumpção  JA Visintin 《Reproduction in domestic animals》2016,51(1):26-32

Spermatogonial stem cells (SSC) have important applications in domestic animal reproduction and advanced biotechnologies. Because differential plating is one of the most common methods used for SSC enrichment, the goal of this study was to compare three differential plating methods for the enrichment of bovine SSC. To achieve this goal, testicular parenchyma from pre‐pubertal calves was minced and single cells were obtained after two enzymatic digestions. We compared three coating methods for differential plating: laminin (20 ng/ml), BSA (0.05 mg/ml) and PBS. Cells were incubated at 37°C, 5% CO₂ in air for 15 min onto laminin‐coated dishes or 2 h onto BSA‐ or PBS‐coated dishes. Cell viability was assessed by trypan blue exclusion method. Recovered cells were analysed for the expression of SSC molecular markers by quantitative RT‐PCR (GFRA1, CXCR4, ITGA6, THY1) and flow cytometry (GFRA1, CXCR4 and ITGA6). Cells at time 0, adherent cells on laminin and non‐adherent cells from BSA and PBS groups had the same cell viability (p = 0.0655). GFRA1, CXCR4 and THY1 relative gene expression was higher (p = 0.0402, p = 0.0007, p = 0.0117, respectively) for non‐adherent cells selected in PBS group. Flow cytometry analysis revealed that the presence of GFRA‐positive (GFRA+) cells was higher in non‐adherent cells from BSA and PBS groups (p < 0.001). However, laminin‐adherent cells had higher number of ITGA6+ cells (p < 0.001) and lower presence of CXCR4+ cells (p = 0.0012). In conclusion, differential plating is an effective method for the enrichment of bovine undifferentiated spermatogonia and higher expression of SSC markers is obtained without laminin or BSA coating.  相似文献   

Survey of captive parrot populations around Port Phillip Bay,Victoria, Australia,for psittacine beak and feather disease virus,avian polyomavirus and psittacine adenovirus          下载免费PDF全文

CL Hulbert  A Chamings  KA Hewson  PA Steer  M Gosbell  AH Noormohammadi 《Australian veterinary journal》2015,93(8):287-292

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Earthworm extraction by electroshocking does not affect canopy CO₂ exchange, root respiration, mycorrhizal fungal abundance or mycorrhizal fungal vitality     

Philip L Staddon  Nick OstleAlastair H Fitter 《Soil biology & biochemistry》2003,35(3):421-426

Electroshocking has been used to manipulate earthworm populations in agroecosystems. However, data on the effects of electroshocking on vegetation are lacking. Here we report on a field experiment with the aim to validate electroshocking as a means of manipulating earthworms without otherwise affecting the soil-plant system. We showed that there was no effect of electroshocking on canopy CO₂ exchange, root respiration or mycorrhizal fungal abundance and vitality (i.e. the proportion of mycorrhizal fungal structure which was alive). The potential for using electroshocking to manipulate earthworm populations in the field and test ecological hypotheses relating to the role of soil biodiversity in soil processes is discussed.  相似文献   

Metabolic blood profile of beef heifers during oestrous and non‐oestrous states          下载免费PDF全文

EM Crane  JC Munro  SL Bourgon  M Diel de Amorim  R Ventura  AH Fredeen  YR Montanholi 《Reproduction in domestic animals》2016,51(5):819-826

Haematological metabolic profiles in heifers could contribute to the development of proxies for oestrous detection and provide clues to further characterize biological changes during oestrus. One hundred and seven beef heifers were observed for oestrous behaviour twice daily for 124 days. Feed intake and productive performance (body weight and composition) traits were measured, and feed efficiency was determined using residual feed intake (kg DM/day). Blood plasma samples were collected when signs of oestrus were observed and every 30 ± 2 days. Heifers were considered in oestrus (n = 71) when plasma progesterone concentrations were <0.6 ng/ml. Least square means of blood metabolic parameters were compared between oestrous and non‐oestrous states and within oestrous groups according to performance traits and age. Heifers in oestrus exhibited higher concentrations of alkaline phosphatase, aspartate aminotransferase (AST), beta‐hydroxybutyric acid, creatine kinase (CK) and triiodothyronine (T3) than heifers in non‐oestrus. Heifers in oestrus revealed lower osmolality and concentrations of calcium, sodium and total protein than during non‐oestrus. Younger (and smaller) heifers had greater concentrations of CK, gamma‐glutamyl transferase (GGT), glucose and sodium than the older heifers. Heifers with lower fatness had increased osmolality and concentrations of cholesterol, CK, phosphorus, sodium and reduced T3 levels. Feed efficient heifers had greater levels of AST, cholesterol and GGT than inefficient heifers. Blood plasma parameters may be complementary to oestrous detection upon further validation; effects of age, feed efficiency, body size and body composition should be considered to optimize this haematological assessment.  相似文献   

Humid‐thermal index for a new management approach of Ommatissus lybicus     

Rashid Al Shidi  Lalit Kumar  Salim AH Al‐Khatri 《Pest management science》2019,75(11):3060-3069

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The Renin-Angiotensin System in the Bovine Utero-Placental Unit     

AH Nielsen  KH Schauser  H Winther  V Dantzer  K Poulsen 《Reproduction in domestic animals》2000,35(3-4):153-156

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ANGIOGRAPHIC APPEARANCE OF COMMON CAROTID COLLATERAL CIRCULATION IN THE GOAT RESULTING FROM PROSTHETIC GRAFT IMPLANTATION     

John T.  Hathcock  DVM  MS  Ram C.  Purohit  BVSc & AH  PHD  Jan E.  Bartels  DVM  MS  Gerald H.  Hankes  DVM  PHD  Shei-Wen  Lee  DVM  MS  Luisito S.  Pablo  DVM  MS 《Veterinary radiology & ultrasound》1989,30(5):227-231

Carotid arteriography was performed in six normal goats. The same procedure was performed on these six and 112 other goats at various time intervals after placement of an arterial graft in one or both carotid arteries. An arterial catheter was introduced into the femoral artery and advanced to the origin of the brachiocephalic trunk with the aid of image-intensified fluoroscopy. Hand-injection of the contrast medium resulted in complete opacification of both common carotid arteries in normal animals. Opacification of one or both of the vertebral arteries was usually seen in the goats with prosthetic grafts. The left vertebral artery was seen more often than the right, and when both vertebral arteries were seen together, the left was often larger. This angiographic method proved to be reliable for opacifying both common carotid arteries from their origin on the brachiocephalic trunk to the cranial cervical region. No clinical problems were associated with either the catheterization procedure or with the permanent ligation of the catheterized femoral artery.  相似文献