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排序方式: 共有194条查询结果,搜索用时 15 毫秒
101.
Tania Manzanos Glen R. Stanosz Denise R. Smith Jannes Muenchow Patrick Schratz Alexander Brenning Ana Aragons Eugenia Iturritxa 《Forest Pathology》2019,49(1)
Diplodia sapinea and Diplodia scrobiculata are opportunistic pathogens of Pinus species. Several studies about taxonomy, impact and epidemiology of these fungi have been conducted in previous years, which have provided useful information and have raised new issues. These diseases produce a considerable impact on plantations resulting in significant economic losses. The main aims of this study are to increase the knowledge of the potential of genetic exchange and the relative aggressiveness of these organisms that can persist in healthy tissues of asymptomatic trees. A collection of 250 isolates among which are 149 strains collected from Pinus radiata plantations in Basque Country (Spain) and 101 strains from different countries was included in this work. Mating type ratios were analysed and compared using the structure of the MAT locus (MAT1‐1‐1 and MAT1‐2‐1). Inoculations of Pinus radiata seedlings were performed in a biosafety greenhouse (P2) to confirm pathogenicity of isolates and compare their aggressiveness. The frequency of occurrence of both idiomorphs of D. sapinea in Basque Country isolates was close to 1:1, however, for collection of isolates of this fungus from around the world, the ratio was 1:2. Furthermore, the spatial distribution of the two mating types in the Basque Country was random. Despite no detection of a sexual state, these results could suggest sexual reproduction behaviour. The pathogenicity of all strains in the collection was confirmed. Although aggressiveness (in terms of lesion lengths resulting from inoculation) varied greatly, no statistically significant effects of MAT type or pathogen species were detected. 相似文献
102.
OBJECTIVE: To use an amplified ELISA technique to document the presence and quantify the concentration of the house dust mite allergen, Der f 1, in skin and coat dust samples collected from dogs. ANIMALS: 29 pet dogs of various breeds. PROCEDURE: Dogs were weighed, and body surface area in square meters was determined. Skin and coat dust samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard and amplified ELISA techniques. RESULTS: By use of the standard ELISA technique, Der f 1 was detected in skin and coat dust samples from 6 of 29 (21%) dogs. Mean concentration of Der f 1 in the 6 samples with positive assay results was 16.16 ng/mL (range, 5.61 to 31.24 ng/mL). Samples with negative assay results were retested for dust mite allergen by use of an amplified ELISA technique; an additional 14 dogs had positive assay results. Mean concentration of allergen was 0.36 ng/mL (range, 0.19 to 2.20 ng/mL). Combining both techniques, 20 of 29 (69%) dogs had positive assay results for Der f 1. CONCLUSIONS AND CLINICAL RELEVANCE: Results of our study indicate that house dust mite allergens are present on the skin and in the coat of dogs, and this source of allergen may act as a reservoir for allergen exposure in hypersensitive dogs. Use of an amplified ELISA technique to determine environmental concentrations of house dust mite allergens in homes and on dogs will help to identify the relationship between immunologic findings and environmental exposures in dogs with atopic dermatitis. 相似文献
103.
OBJECTIVE: To characterize Pasteurella spp isolated from healthy pack goats and evaluate the effects of administration of a commercial Pasteurella vaccine. ANIMALS: 45 goats. PROCEDURE: Pharyngeal swab specimens and blood samples were collected on day 0 before vaccination with a Pasteurella (Mannheimia) haemolytica serotype A1 bacterin. Samples were also collected from 17 goats on days 21 and 35. Isolated Pasteurella spp were assigned to biovariant groups on the basis of results of biochemical utilization tests and serotyped. Serum antibody titers were determined. RESULTS: Multiple strains of Pasteurella spp were isolated from swab specimens and assigned to 30 nonhemolytic and 14 beta-hemolytic biovariant groups. The most common biovariant isolated was nonhemolytic P trehalosi belonging to group 2. This strain was isolated from 41 goats. Nonhemolytic P haemolytica strains were isolated from 31 goats, whereas beta-hemolytic strains of P trehalosi and P haemolytica were isolated from 8 and 35 goats, respectively. Vaccination with the A1 serotype did not affect the proportion of goats from which we isolated each biovariant group or the number of biovariant groups isolated. CONCLUSIONS AND CLINICAL RELEVANCE: Multiple strains of P haemolytica and P trehalosi belonging to nonhemolytic and beta-hemolytic biovariant groups were isolated from the pharynx of healthy domestic pack goats. Because hemolytic activity correlates with leukotoxin production, beta-hemolytic strains may have a greater potential to cause disease in naive populations of wild ruminants. However, vaccination with an A1 serotype bacterin did not decrease the proportion of culture-positive goats. 相似文献
104.
Jonathan M Frantz Glen Ritchie Nilton N Cometti Justin Robinson Bruce Bugbee 《Journal of the American Society for Horticultural Science》2004,129(3):331-338
The productivity of lettuce in a combination of high light, high temperature, and elevated CO2 has not been commonly studied because rapid growth usually causes a calcium deficiency in meristems called tipburn, which greatly reduces quality and marketability. We eliminated tipburn by blowing air directly onto the meristem, which allowed us to increase the photosynthetic photon flux (PPF) to 1000 micromoles m-2 s-1 (57.6 mol m-2 d-1); two to three times higher than normally used for lettuce. Eliminating tipburn doubled edible yield at the highest PPF level. In addition to high PPF, CO2 was elevated to 1200 micromoles m-2 mol-1, which increased the temperature optimum from 25 to 30 degrees C. The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield. Photosynthetic efficiency, measured as canopy quantum yield in a whole-plant gas exchange system, steadily increased up to the highest temperature of 32 degrees C in high CO2. The highest productivity was 19 g m-2 d-1 of dry biomass (380 g d-1 fresh mass) averaged over the 23 days the plants received light. Without the limitation of tipburn, the combination of high PPF, high temperature, and elevated CO2 resulted in a 4-fold increase in growth rate over productivity in conventional environments. 相似文献
105.
A Judith Cawdell-Smith Robert A E Pym Rodney G Verrall Mark A Hohenhaus Andrew Tribe Glen T Coleman Wayne L Bryden 《Journal of veterinary medical education》2007,34(5):542-549
Students in animal science and veterinary science at the University of Queensland (UQ) have similar introductory courses in animal handling in year 1 of their degree programs. Veterinary students take animal-handling instruction in farm and companion animals, whereas animal science students are instructed in handling farm animals, horses, and rodents. Veterinary students are introduced to rodents, and animal science students to dogs and cats, in subsequent years of the curriculum. Both cohorts receive additional training, with clinical emphasis for veterinary students in years 3, 4, and 5 of their five-year curriculum. The introductory course is well received by students; both student cohorts appreciate the opportunity provided and the effort that goes into the animal-handling classes. Undergraduates realize that acquiring animal-handling skills will increase their proficiency in their subsequent careers; veterinary graduates recognize that their handling prowess will give their clients confidence in their abilities. Most clients cannot judge the competence of a veterinarian's diagnosis or treatment but will judge their ability based on their handling skills. Ongoing practice allows students to become competent in animal handling. 相似文献
106.
Hahn KA Endicott MM King GK Harris-King FD 《Journal of the American Veterinary Medical Association》2007,231(5):742-745
OBJECTIVE: To determine whether the addition of doxorubicin chemotherapy affected the outcome of cats with incompletely excised, nonvisceral soft tissue sarcomas undergoing postoperative radiotherapy. DESIGN: Retrospective case series. ANIMALS: 71 cats. PROCEDURES: Medical records were reviewed for clinically relevant data on cats that underwent postoperative radiotherapy for treatment of incompletely excised soft tissue sarcomas with or without concurrent doxorubicin chemotherapy. Radiotherapy was performed on an alternate-day schedule, with a total dose of 58.8 to 63 Gy delivered in 21 fractions. Doxorubicin was administered every 21 days for 3 to 5 cycles. Follow-up information was obtained by means of physical examination or through telephone conversations with refer-ring veterinarians or owners. RESULTS: Median disease-free interval with concurrent radiotherapy and doxorubicin chemotherapy (15.4 months; range, 2.4 to 44.9 months) was significantly longer than median disease-free interval with radiotherapy alone (5.7 months; range, 1.0 to 50.8 months). However, survival time was not significantly different between groups. CONCLUSION AND CLINICAL RELEVANCE: Results suggested that doxorubicin chemotherapy may play a role in extending the disease-free interval in cats undergoing radiotherapy for treatment of incompletely excised soft tissue sarcomas. 相似文献
107.
M. Glen N.L. Bougher I.J. Colquhoun S. Vlahos W.A. Loneragan P.A. O’Brien G.E.St.J. Hardy 《Forest Ecology and Management》2008
Species richness and species composition of ectomycorrhizal (EM) fungi were compared among rehabilitated mine sites and unmined jarrah forest in southwest Western Australia. Species richness, measured in 50 m × 50 m plots, was high. In the wetter, western region, mean species richness per plot in 16-year-old rehabilitated mine sites (63.7 ± 2.5, n = 3) was similar to that of unmined jarrah forest (63.6 ± 9.6, n = 9). In the drier, eastern region, species richness in 12-year-old rehabilitated mine sites (40.3 ± 2.1, n = 3) approached that of nearby forest (52.4 ± 9.3, n = 9). Species composition was analysed by detrended correspondence analysis. Rehabilitated sites of similar age clustered together in the analysis and species composition was closer to the native jarrah forest in the older rehabilitated plots. In unmined forest, species composition of fungal communities in the wetter, western region was different from communities in the drier, eastern region. 相似文献
108.
Theresa K. Herman Jaeyeong Han Ram J. Singh Leslie L. Domier Glen L. Hartman 《Plant Breeding》2020,139(5):923-931
The genetic base for soybean cultivars is narrow compared to most other crop species. Twenty-seven wild perennial Glycine species comprise the tertiary gene pool to soybean that may contain many genes of economic importance for soybean improvement. We evaluated 16 accessions of G. argyrea, G. clandestina, G. dolichocarpa, and G. tomentella for resistance to Heterodera glycines (HG), also known as the soybean cyst nematode, and to multiple isolates of Phakopsora pachyrhizi, the causal fungus of soybean rust. All 16 accessions were classified as resistant to H. glycines HG Type 2.5.7, based on number of cysts per root mass with plant introductions (PIs) 483227, 509501, 563892, and 573064 (all G. tomentella) void of any cysts indicating no reproduction by this pest. All 16 accessions had an immune reaction to one isolate of P. pachyrhizi. Regardless of isolate, no sporulating uredinia were observed on G. argyrea (PI 505151) and G. tomentella (PIs 483227, 509501, and 573064). These results demonstrate that some accessions within the perennial Glycine species harbour resistance to both H. glycines and P. pachyrhizi and would be good candidates for wide hybridization programs seeking to transfer potentially unique multiple resistance genes into soybean. 相似文献
109.
Lopa Goradia Glen L. Hartman Steven L. Daniel 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(2):331-335
Xanthomonas axonopodis pv. glycines causes bacterial pustule of soybean, which is a common disease in many soybean-growing areas of the world and is controlled
by a single recessive gene (rxp gene) commonly found in many conventional glyphosate-sensitive soybean cultivars. Since glyphosate-tolerant cultivars are
commonly planted today, there has been no information about whether these new cultivars have bacterial pustule resistance.
The goal of this study was to screen glyphosate-tolerant soybean cultivars for resistance to X. axonopodis pv. glycines. Three experiments were completed to evaluate resistance. In experiment 1, 525 commercial glyphosate-tolerant cultivars from
2001 were inoculated with X. axonopodis pv. glycines strain UIUC-1. Following inoculation, many of the cultivars were resistant (developed no detectable pustule symptoms) although
152 (~29%) developed bacterial pustule. In experiment 2, the aggressiveness of three strains (UIUC-1, UIUC-2, and ATCC 17915)
of X. axonopodis pv. glycines were compared on three bacterial pustule-susceptible, glyphosate-tolerant cultivars. One strain (UIUC-1) was less aggressive
than the other two (UIUC-2 and ATCC 17915) on all three cultivars examined. In experiment 3, 45 cultivars from 2005 (all different
from 2001) were inoculated with X. axonopodis pv. glycines ATCC 17915. A range of disease severities developed with five cultivars (11%) having disease severity ratings as high as
or higher than those on a susceptible check cultivar. Overall, these results suggested that resistance to bacterial pustule
occurs in glyphosate-tolerant soybean cultivars, but not at 100% frequency, which means bacterial pustule outbreaks could
occur when a susceptible cultivar is planted and conditions are conducive for bacterial pustule development. 相似文献
110.
多巴胺拮抗物 pimozide(PIM)或排除剂 reserpine(RES)和促黄体素释放激素类似物(LHRH-A)诱导养殖鱼类促性腺激素分泌和排卵的研究 总被引:2,自引:0,他引:2 下载免费PDF全文
由多巴胺拮抗物PIM或排除剂RES组成的高效新型鱼类催产合剂能有效的诱导主要的淡水养殖鱼类促性腺激素分泌和产卵,其中青鱼催产率为80%,鲢鱼为84%,鳙鱼和草鱼为88%,长春鳊为94%,鲮鱼为96%。试验表明这种催产剂的主要优点是:催产效果高而稳定,可以完全取代鱼脑垂体;对当年第二次成熟和产卵的亲鱼同样有效;有利于保护亲鱼;节省劳力和成本。 相似文献