Components of resistance to late blight (Phytophthora infestans) in eight South AmericanSolanum species     

Leontine T. Colon  Dirk J. Budding  L. C. Paul Keizer  Martin M. J. Pieters 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(4):441-456

Four components of partial resistance toPhytophthora infestans were measured after inoculation in the greenhouse and in the field ofSolanum arnezii x hondelmannii, S. berthaultii, S. circaeifolium, S. leptophyes, S. microdontum, S. sparsipilum, S. sucrense andS. vernei, and four hybrid progenies ofS. microdontum withS. tuberosum. The four components were infection efficiency, lesion growth rate, generation time and sporulation capacity. The results were compared with resistance ratings derived from field experiments, and with observations made on the potato cultivars Bintje, Bildstar, Libertas and Pimpernel. Genetic variation for all components was found, while the relative importance of the components of partial resistance appeared to vary between the species. InS. microdontum, generation time, infection efficiency and lesion growth rate, and inS. tuberosum infection efficiency, lesion growth rate and sporulation capacity appeared positively associated, but in other species no such association was found. A strong hypersensitive reaction, the expression of which appeared to depend on environmental conditions, was found inS. microdontum. ForS. berthaultii, infection efficiency appeared to be the main resistance component.Abbreviations ADPC area under the disease progress curve - IE infection efficiency - LGR lesion growth rate - GT generation time - SC sporulation capacity  相似文献   

Metal chelate molluscicides: The redistribution of iron diazaalkanolates from the gut lumen of the slug,Deroceras reticulatum (Müller) (Pulmonata: Limacidae)     

Suzanne J. Clark  Nicola P. Coward  Glenn W. Dawson  Ian F. Henderson  Andrew P. Martin 《Pest management science》1995,44(4):381-388

Two related iron chelates, one toxic to slugs by ingestion, the other not, were introduced into the foregut of D. reticulatum. The subsequent movement and redistribution of the metal within the slug tissues was studied by labelling the chelates with the radioactive isotope ⁵⁵Fe. In slugs which survived treatment approximately half of the ⁵⁵Fe was voided in faeces. The iron retained became unevenly distributed, the highest concentration occurring in the digestive gland, irrespective of the chelate used. At high doses, slugs treated with tris(1-oxo-1,2-diazabutan-2-oxido)Fe(III) were fatally poisoned while those treated with the homologue, tris(1-oxo-1,2-diazaoctan-2-oxido)Fe(III) were not. Slugs killed by the toxic chelate consistently contained proportionally less iron in the digestive gland and proportionally more in the body wall and reproductive system. Dosing slugs already killed by carbon dioxide asphyxiation gave a similar pattern, suggesting that the greater mobility of the iron from the toxic chelate was not a function of the slugs' metabolism.  相似文献   

Brow suspension for treatment of ptosis and entropion in dogs with redundant facial skin folds     

Willis AM  Martin CL  Stiles J  Kirschner SE 《Journal of the American Veterinary Medical Association》1999,214(5):660-662

Brow suspension surgery was performed on 7 dogs with redundant facial skin folds, associated ptosis, and entropion. The surgical technique involved subcutaneous placement of polyester mesh strips to suspend the upper eyelid from the dorsal frontalis muscle and the underlying periosteum of the skull. Visual impairment associated with ptosis was resolved in all dogs at the 2 week reevaluation period. Upper eyelid position was maintained in 4 of 7 dogs available for long-term follow-up. One dog developed persistent draining tracts in the region of the implant, and removal of part of the implanted mesh was eventually required. Upper eyelid height in this dog, however, was maintained following mesh removal, probably because of fibrosis around the implant. Brow suspension is an option for surgical management of upper eyelid ptosis and entropion in dogs with redundant skin folds and avoids the need for facial skin fold excision.  相似文献   

Day length affects feeding behaviour and food intake in adult male emus (Dromaius novaehollandiae)     

Blache D  Martin GB 《British poultry science》1999,40(5):573-578

1. In south-western Australia, male and female emus decrease their food intake when they start breeding in early winter and increase their intake during spring and summer when the breeding season and egg incubation are finished. 2. This annual feeding cycle seems to be under the influence of several environmental factors. Here, we tested the importance of photoperiod using male emus kept in light-controlled rooms with ad libitum access to food and water. 3. Long days increased food intake whereas short days decreased it. Emus fed only during the light hours. 4. Frequency of meals was similar under the 2-day lengths but meal duration was shorter when the emus were on short days than when they were on long days. Thus, day length seemed to affect appetite but not interest in food. 5. Further investigations are needed to test whether these changes in feeding behaviour are a direct consequence of day length or if they are secondary to photoperiod-driven changes in sexual activity.  相似文献   

The associations of viral and mycoplasmal antibody titers with respiratory disease and weight gain in feedlot calves          下载免费PDF全文

Martin SW  Nagy E  Armstrong D  Rosendal S 《The Canadian veterinary journal. La revue veterinaire canadienne》1999,40(8):560-7,570

Blood samples from 32 groups of calves (n = 700) were taken on arrival and after 28-35 days at the feedlot. Eleven groups were housed in feedlots in Ontario, and 21 groups in feedlots in Alberta. Serum antibody titers to bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PIV-3), infectious bovine rhinotracheitis virus (IBRV), Mycoplasma dispar and M. bovis, plus data on bovine corona virus (BCV) from a previous study were investigated for their association with the risk of bovine respiratory disease (BRD), and with 28-day weight change, both before and after controlling for titers to Pasteurella haemolytica and Haemophilus somnus. Exposure to IBRV and M. bovis was infrequent, and although exposure to PIV-3 was more common, none of these agents had important associations with BRD. Higher titers to BVDV, BRSV, and BCV on arrival were associated with reduced risks of BRD and increased weight gains. However, there was some variation in these relationships and higher arrival titers to BVDV and BRSV in a subset of the calves were associated with increased risks of BRD. Titer increases to BVDV were associated with a higher risk of BRD and lower weight gains. Titer increases to BRSV were not usually associated with the occurrence of BRD, but titer increases to BRSV in a subset of calves that were vaccinated against BRSV, on arrival, were associated with an elevated risk of BRD. Of all the agents studied, BVDV had the most consistent associations with elevated risk of BRD and lower weight gains. Higher BRSV arrival titers were related to lower risk of BRD and higher weight gains; in some instances titer increases to BRSV were associated with higher BRD risk. Higher titers to BCV on arrival were related to reduced risks of BRD. Practical ways of adequately preventing the negative effects of these agents are still needed.  相似文献   

The Effects of Intercrop Spacing Patterns on the Silage Yield of Maize and Soybean     

R. C. Martin    H. D. Voldeng  D. L. Smith 《Journal of Agronomy and Crop Science》1991,167(2):81-90

The effects of intercrop spacing patterns on the silage yields of both maize (lea mays L.) and soybean (Glycine max [L.] Merr.) were examined from 1985 to 1987. Dwarf maize was intercropped with nonnodulatmg or nodulating soybean in the spacing patterns, S_40same (two crops in the same row, 40 cm row width) and S_20ait or S_40ak (two crops in alternate rows, 20 cm or 40 cm row width, respectively). Tall maize was intercropped with nodulating soybean in S_40sames S_40alt and S_40pair (maize in 40 cm paired rows, soybean rows 20 cm outside each maize row and 80 cm from the next set of four rows) at 0 or 60 kg N ha⁻¹ and at population densities of 67% maize: 67% soybean or 50 % maize: 50% soybean. Maize and soybean were also intercropped and stripcropped on a farm-scale. The only difference between intercrops arranged in the same rows versus those in alternate rows was that the average soybean protein yields were higher in S_40same than in S_40alt. In 1986, the S_40alt maize-soybean intercrops produced higher maize yields, total biomass yields and Land Equivalent Ratios (LERs) than in S_40pirs, and in 1987, these responses were higher in intercrops than in stripcrops. In 1986, at 0 kg N ha⁻¹, the soybean biomass and protein yields were lower in S_40alt, than in S_40pairs and in 1987, these responses were lower in intercrops than in stripcrops.  相似文献   

Hepatic vasculopathy and encephalopathy in Brahman-type calves     

PA GILL  WL TOWNSEND 《Australian veterinary journal》1993,70(2):69-69

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Capillary Supply During Development of Individual Regenerating Muscle Fibers     

E. Luque    J. Peña    P. Martin    I. Jimena  R. Vaamonde 《Anatomia, histologia, embryologia》1995,24(2):87-89

This study describes the capillary supply of individual regenerating muscle fiber during three stages of its development. Regeneration was induced by the injection of mepivacaine in the anterior tibial muscle of rats. Muscle fiber capillarization during regeneration was analysed in semithin sections, employing the following parameters: the number of capillaries around a fiber and the number of capillaries per fiber cross-sectional area. The results revealed that during development of regenerating fibers, the fiber cross-sectional area increased, the number of capillaries around each fiber increased and the number of capillaries per fiber cross-sectional area decreased. These data indicated a greater capillary supply of the individual regenerating muscle fiber during its early stage of maturation.  相似文献   

The effects of two shipping treatments on the carcass characteristics of bulls implanted with zeranol and unimplanted steers     

S D Jones  J A Newman  A K Tong  A H Martin  W M Robertson 《Journal of animal science》1986,62(6):1602-1608

A total of 144 male crossbred calves were allocated to four management treatments (bulls; steers; bulls implanted with zeranol at 100 d of age and re-implanted at 69, 93 and 56 d thereafter; bulls implanted with zeranol at 168 d of age and re-implanted at 93 and 56 d thereafter), and two pre-slaughter shipping treatments (minimum pre-slaughter stress with cattle shipped and slaughtered within 4 h of leaving the feedlot pen; moderate pre-slaughter stress with cattle mixed, trucked 160 km and slaughtered up to 24 h of leaving the feedlot pen) in a 4 X 2 factorial arrangement. Management treatment had no significant effect on carcass pH (45 min), carcass muscle temperature (45 min), or peak shear-force of cooked longissimus muscle. Steers had significantly lower dressing percentage, warm-carcass weight, hide weight and carcass-lean content, but higher marbling score, fat thickness and intramuscular-fat content than all treatments with bulls. Minimum pre-slaughter stress resulted in significantly lower dressing percentage, warm-carcass weight, and carcass pH (45 min), but generally had no effect on carcass tissue-yield measurements compared with the moderate stress treatment. Implanted bulls produced carcasses with significantly darker meat, higher 24-h pH and lower meat expressible juice than bulls and castrates for the moderate pre-slaughter stress treatment. These results provide evidence that zeranol implantation in bulls had a minor influence on carcass characteristics, and did not reduce the incidence of dark-cutting carcasses in young bulls subjected to moderate pre-slaughter shipping stress.  相似文献   

Studies on liquid hemicellulose and cane molasses as carbohydrate sources in urea-containing diets of sheep     

D L Williams  J D Moore  L C Martin  A D Tillman 《Journal of animal science》1969,28(5):667-672

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