Genetic analysis of the maximum germination distance of Striga under Fusarium oxysporum f. sp. strigae biocontrol in sorghum     

Emmanuel Mrema  Hussein Shimelis  Mark Laing  Learnmore Mwadzingeni 《农业科学学报》2018,17(7):1585-1593

Maximum germination distance(MGD) is an important component of Striga resistance in sorghum. The objective of this study was to determine gene action influencing MGD of Striga hermonthica and Striga asiatica among selected sorghum lines treated with a biocontrol agent, Fusarium oxysporum f. sp. strigae(FOS) for effective breeding with Striga resistance, and FOS compatibility. Twelve sorghum genotypes were selected based on their Striga resistance, FOS compatibility, and superior agronomic performance. Selected genotypes were crossed using a bi-parental mating design to generate six families for genetic analysis. Agar-gel assays were used to determine low haustorium initiation factor(LHF) using the 12 parental lines, their F_1 progenies, backcross derivatives, and F_2 segregants in two sets. One set had S. hermonthica seed and the other one had S. asiatica seed. Both were treated with and without FOS. Genotypes were evaluated using a split-plot design with three replications and MGD data were recorded followed by generation mean analysis. FOS reduced MGD by 1cm under both S. hermonthica and S. asiatica infestations. Additive, dominance, and epistatic gene actions were involved in the control of MGD of the two Striga species in the evaluated populations. On average, the relative contribution of additive, additive×additive and dominance×dominance genetic effects on the MGD of S. hermonthica and S. asiatica, with FOS, were 20, 33, and 36%; and 21, 32, and 35%, respectively. Breeding methods exploiting these genetic effects may provide enhanced response to selection for Striga resistance and FOS compatibility in integrated Striga management(ISM) programmes.  相似文献   

Possible bitertanol and fuberidazole poisoning in young pheasants     

Laing PW 《The Veterinary record》2001,149(4):118-120

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TGF-beta3 exists in bony fish     

Laing KJ  Pilström L  Cunningham C  Secombes CJ 《Veterinary immunology and immunopathology》1999,72(1-2):45-53

A partial nucleotide sequence of transforming growth factor-beta3 (TGF-beta3) has been isolated from the Siberian sturgeon (Acipenser baeri), rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla), confirming a ubiquitous presence in the ray-finned (Actinopterygian) bony fish. The bony fish TGF-beta3 is highly conserved, with some 83-84% nucleotide identity (coding region) and 90-95% predicted amino acid identity to known homeotherm TGF-beta3's. Far lower homologies are apparent with other known TGF-beta isoforms in fish (e.g. 64-66% and 81-82% amino acid identity to trout TGF-beta 1/5 and carp TGF-beta2 respectively). Phylogenetic tree analysis showed that the fish TGF-beta3's clustered with the known homeotherm TGF-beta3's. The relatively tight clustering of TGF-beta1, TGF-beta2 and TGF-beta3 was in contrast to the TGF-beta5's, which are clearly a more heterogenous group.  相似文献   

Effect of Quil A,a saponin derivative,on the response of sheep to alum precipitatedBacteroides nodosus vaccines     

J. R. Egerton  E. A. Laing  C. M. Thorley 《Veterinary research communications》1978,2(1):247-252

Alum precipitatedBacteroides nodosus vaccines prepared from two antigens with and without the saponin derivative, Quil A, did not induce adverse tissue reactions in sheep injected subcutaneously. Vaccinated, non-infected Merino sheep had higher agglutinin antibody titres when the vaccines included Quil A. Moreover, the recovery rates in vaccinated sheep affected with foot-rot were higher when the vaccines included Quil A.  相似文献   

The occurrence, prevalence and transmission of Bacteroides nodosus infection in cattle   总被引：1，自引：0，他引：1  

E A Laing  J R Egerton 《Research in veterinary science》1978,24(3):300-304

Following reports of findings of ovine foot-rot flora in the feet of cattle, a study was undertaken to determine the prevalence of Bacteroides nodosus infection in the apparently normal cattle population. We found that 34.5 to 74.2 per cent of the animals examined on different farms had B nodosus present in one or more feet. B nodosus was not the most prevalent bacterium observed in smears from cattle. Other Gram negative species including Fusiformis necrophorus and many Gram positive cocci and coccobacilli were also present. Macroscopic lesions in the interdigital skin characterised by erosion and hyperkeratosis were usually associated with the occurrence of B nodosus. B nodosus isolated from cattle induced mild interdigital dermatitis in experimental cattle and sheep and the infection was transmitted to recipient cattle and sheep under field conditions. Virulent foot-rot of sheep was not transmitted to recipient cattle in conditions where the disease spread to susceptible sheep.  相似文献   

Large-scale turbidostat culture of marine microalgae     

I. Laing  E. Jones 《Aquacultural Engineering》1983,2(3):203-212

A simple and inexpensive device is described which maintains cultures of marine microalgae at predetermined cell densities by the automatic control of harvesting and replenishment of the culture volume with fresh medium. Cultures were maintained at a range of cell densities in 80-litre internally illuminated vessels and the daily cell production yield was evaluated.Maximum yields of 0·8–1·0×10¹² cells day^?1 of Isochrysis aff. galbana Green and 0·8–1·2×10¹¹ cells day^?1 of Tetraselmis suecica (Kylin) Butch. were obtained at culture densities of 15–17×10³ cells μlitre^?1 and 19–21×10² cells μlitre^?1, respectively. Turbidostat cultures of Skeletonema costatum (Grev.) Cleve could not consistently be maintained above 5–7×10³ cells μlitre^?1.  相似文献   

Combining ability and gene action of three components of horizontal resistance against rice blast     

Quaqua S. Mulbah  Hussein A. Shimelis  Mark D. Laing 《Euphytica》2015,206(3):805-814

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How management strategies have affected Atlantic White-cedar forest recovery after massive wind damage in the Great Dismal Swamp     

Joelle M. Laing  Theodore H. Shear 《Forest Ecology and Management》2011,262(8):1337-1344

In September 2003 Hurricane Isabel swept through eastern North Carolina and Virginia, destroying most of what formerly ranked among the most extensive remaining stands of Atlantic White-cedar (Chamaecyparis thyoides L., cedar). As Atlantic White-cedar communities are dependent on irregular, large-scale disturbances, the hurricane event can be viewed as an opportunity for perpetuating cedar populations in the Great Dismal Swamp. The success of cedar regeneration in the Dismal Swamp has been influenced by the management strategies employed by Great Dismal Swamp National Wildlife Refuge (active management) and by the adjacent Dismal Swamp State Park (passive management). We investigated the regeneration success of Atlantic White-cedar 5 years following Hurricane Isabel by sampling five stands at the Dismal Swamp State Park withstanding varying impact from the storm and previous windthrow events. We compared our findings to regeneration surveys completed at the adjacent Great Dismal Swamp National Wildlife Refuge. Atlantic White-cedar seedling densities were up to 100 times higher in the actively managed Wildlife Refuge compared to the passively managed State Park. We also determined the seedbank of viable cedar seeds and we described the vegetation at the State Park. The stands at the State Park are now dominated by red maple (Acer rubrum) with a dense shrubby understory. Since viable cedar seeds were still present in the seedbank (>800,000 ha⁻¹), future seedling establishment is possible at the State Park. However, active management is essential for achieving sufficient seedling densities and survival for regenerating a mature cedar stand.  相似文献   

Treatment of cyclophosphamide-induced hemorrhagic cystitis in five dogs     

E J Laing  C W Miller  S M Cochrane 《Journal of the American Veterinary Medical Association》1988,193(2):233-236

Sterile hemorrhagic cystitis developed in 5 dogs after treatment with cyclophosphamide. Four dogs were being treated with various antineoplastic protocols, and the fifth dog had recurrent immune-mediated thrombocytopenia. In all instances, clinical signs of hematuria and stranguria persisted after cyclophosphamide administration was discontinued. Three dogs required cystotomy to remove necrotic mucosa and calculi. The other 2 dogs were treated with intravesicularly administered dimethyl sulfoxide to decrease inflammation and to inhibit fibroplasia of the bladder wall. In 4 dogs, clinical signs resolved after treatment. The fifth dog, treated surgically, continued to have intermittent urinary incontinence attributable to residual bladder wall fibrosis.  相似文献   

Pulmonary changes associated with flotation techniques in the treatment of skeletal injuries in the horse     

S A McClintock  D R Hutchins  E A Laing  M A Brownlow 《Equine veterinary journal》1986,18(6):462-466

Six adult horses with normal blood gas values, normal thoracic radiographs and free from overt signs of respiratory disease were confined in flotation tanks for periods from one to seven weeks. With one exception, they all coughed, had a variable amount of nasal discharge and, at autopsy, showed cranio-ventral alterations to their lungs which were characterised by patchy irregular areas of absorption atelectasis with or without an inflammatory reaction and an accompanying alveolar emphysema.  相似文献