Predicting spring barley yield from variety-specific yield potential, disease resistance and straw length, and from environment-specific disease loads and weed pressure   总被引：1，自引：1，他引：0  

Hanne ?sterg?rd  Kristian Kristensen  Hans O. Pinnschmidt  Preben Klarskov Hansen  Mogens S. Hovm?ller 《Euphytica》2008,163(3):391-408

For low-input crop production, well-characterised varieties increase the possibilities of managing diseases and weeds. This analysis aims at developing a framework for analyzing grain yield using external varietal information about disease resistance, weed competitiveness and yield potential and quantifying the impact of susceptibility grouping and straw length scores (as a measure for weed competitiveness) for predicting spring barley grain yield under variable biotic stress levels. The study comprised 52 spring barley varieties and 17 environments, i.e., combinations of location, growing system and year. Individual varieties and their interactions with environments were analysed by factorial regression of grain yield on external variety information combined with observed environmental disease loads and weed pressure. The external information was based on the official Danish VCU testing. The most parsimonious models explained about 50% of the yield variation among varieties including genotype-environment interactions. Disease resistance characteristics of varieties, weighted with disease loads of powdery mildew, leaf rust and net blotch, respectively, had a highly significant influence on grain yield. The extend to which increased susceptibility resulted in increased yield losses in environments with high disease loads of the respective diseases was predicted. The effect of externally determined straw length scores, weighted with weed pressure, was weaker although significant for weeds with creeping growth habit. Higher grain yield was thus predicted for taller plants under weed pressure. The results are discussed in relation to the model framework, impact of the considered traits and use of information from conventional variety testing in organic cropping systems.  相似文献   

Plant breeding for organic and sustainable,low-input agriculture: dealing with genotype–environment interactions     

Edith T. Lammerts van Bueren  Hanne Østergård  Isabelle Goldringer  Olga Scholten 《Euphytica》2008,163(3):321-322

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Plagiotropism and auxin in Abies nordmanniana     

Veierskov B  Rasmussen HN  Eriksen B  Hansen-Møller J 《Tree physiology》2007,27(1):149-153

Main branches of Abies nordmanniana Spach. were examined through their first growth season from subapical buds around the leader bud to fully expanded shoots. Plagiotropism was evident in branch orientation, which was almost horizontal, as well as in the orientation of buds developing on the branches. Auxin transport capacity was predominantly basipetal (> 90%) and consistently higher in the middle part of the branch than in the distal and proximal ends. Auxin transport capacity was higher on the dorsal side of the branch during the short initial hyponastic growth phase, but the difference disappeared when the branch became horizontal. No dorsal-ventral differences could be detected in young horizontal branches in concentrations of indole acetic acid, cytokinins, gibberellins or abscisic acid. Branch orientation was unaffected by decapitation of the leader apex or by decapitation and replacement with exogenous auxin. However, decapitation resulted in a less plagiotropic bud arrangement on the branches, and auxin application to the leader bud scar counteracted this effect. Thus, a signal originating in the stem seems to be involved in regulating branch bud positioning, whereas the horizontal branch orientation must rely on a different mechanism, presumably autonomic within the branch.  相似文献   

Effect of air exposure on scallop behaviour, and the implications for subsequent survival in culture     

Dan Minchin  Geir Haugum  Hanne Skjæggestad  Øivind Strand 《Aquaculture International》2000,8(2-3):169-182

Scallop spat produced for continued culture normally requiretransportation between sites, and the associated stresses may causemortalities. In the present experiment, scallops of 40–55 mm shell heightwere emersed in air for time intervals up to 24 h and their behaviourexamined once re-immersed. Scallops were placed upside-down and thenumber of movements and the cumulative numbers righting in 5 min timeblocks were recorded. The greatest frequency for all behaviouralresponses was found at 15–17 °C in August. Responses were reducedin November and June (9–11 °C) and least at 5 °C in January.All effects of treatment, temperatures and season, and increases in airexposure were significantly different. Following the treatments, mortalitiesafter 10 days in culture was about 10–30% for scallops emersed for 18 and24 h in August and June. Scallops did not show significantly differentbehaviour whether they were emersed upright or inverted. However,scallops emersed at 15 °C had fewer responses than scallops held at <10 °C, so chilling during transport may prolong scallop vitality. Theresults suggest that air exposure >12 h should be avoided. At temperatures>9 °C, behavioural responses may be a simple and effective method toassess vitality which can assist in the management of scallop culture.  相似文献   

An assessment of forest sector modeling approaches: conceptual differences and quantitative comparison     

Hanne K. Sjølie  Greg S. Latta  Erik Trømborg  Torjus F. Bolkesjø  Birger Solberg 《Scandinavian Journal of Forest Research》2015,30(1):60-72

Forest sector models are widely used for policy and economic analyses. Basic assumptions vary considerably between models, but little attention has been paid to the impacts these differences may have on model results. Norway provides a great opportunity to fill this void as it has two forest sector models currently in use based on different modeling assumptions, but sharing the same data source. In one model, agents are assumed to be myopic in the meaning that they rely only on the current market conditions. Harvest behavior is in this model based on econometric relations and exogenous forest growth rates. The second model approach employs extensive forest data and assumes that agents have perfect information over the model time horizon. We discuss the differences between the two modeling approaches and compare quantitatively the model results of two case studies. However, both types of models are rather sensitive to changes in assumptions and data. The strengths and weaknesses of the two model approaches and their appropriateness for responding to the study questions should be considered when choosing modeling methodology. Using both models in parallel removes the uncertainty caused by the foresight assumption/optimization routine and thus provides in total more information.  相似文献   

Saponin-containing subfractions of soybean molasses induce enteritis in the distal intestine of Atlantic salmon     

Knudsen D  Urán P  Arnous A  Koppe W  Frøkiaer H 《Journal of agricultural and food chemistry》2007,55(6):2261-2267

The current work aimed at tracing the causative components for soybean-induced enteritis in Atlantic salmon (Salmo salar L.). Soybean molasses was subjected to phase separation using n-butanol. Three subfractions were obtained as follows: butanol phase, precipitate, and water phase. The biochemical composition of soybean molasses and the obtained subfractions were analyzed in detail: Protein, fat, and ash were quantified according to standard methods. Sucrose, raffinose, and stachyose were quantified using high-performance anion-exchange chromatography. Soyasaponins were quantified using reverse-phase high-performance liquid chromatography. Finally, sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to evaluate the size distribution of the proteins present in each fraction. Molasses and the different subfractions were thereafter fed to Atlantic salmon in two successive fish trials. The level of intestinal inflammation was evaluated by light microscopy using a semiquantitative scoring system. Histological assessments revealed that Atlantic salmon fed a combination of butanol phase and precipitate displayed significant enteritis. Atlantic salmon fed the water phase displayed normal intestinal morphology. The causative components for soybean-induced enteritis withstand butanol treatment and prolonged heating at 70 degrees C. Sucrose, raffinose, stachyose, nor soybean proteins larger than 10 kDa induce enteritis alone. Soyasaponins, or components that follow the same solubility pattern, trigger the inflammatory reaction. We therefore suggest that soybean-induced enteritis in Atlantic salmon is induced by soyasaponins alone or by soyasaponins in combination with other factors, e.g., antigenic soybean proteins or the intestinal microflora.  相似文献   

Global network reorganization during dynamic adaptations of Bacillus subtilis metabolism     

Buescher JM  Liebermeister W  Jules M  Uhr M  Muntel J  Botella E  Hessling B  Kleijn RJ  Le Chat L  Lecointe F  Mäder U  Nicolas P  Piersma S  Rügheimer F  Becher D  Bessieres P  Bidnenko E  Denham EL  Dervyn E  Devine KM  Doherty G  Drulhe S  Felicori L  Fogg MJ  Goelzer A  Hansen A  Harwood CR  Hecker M  Hubner S  Hultschig C  Jarmer H  Klipp E  Leduc A  Lewis P  Molina F  Noirot P  Peres S  Pigeonneau N  Pohl S  Rasmussen S  Rinn B  Schaffer M  Schnidder J  Schwikowski B  Van Dijl JM  Veiga P  Walsh S  Wilkinson AJ  Stelling J  Aymerich S 《Science (New York, N.Y.)》2012,335(6072):1099-1103

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Response     

Hanne Kortegaard  & Thomas Eriksen  Vibeke Baelum 《The Journal of small animal practice》2009,50(2):104-105

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Endodontic treatment of a tiger     

Kortegaard HE  Qvist J  Nielsen CG  Eriksen T 《Journal of veterinary dentistry》2003,20(3):149-153

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A cross-sectional study of epilepsy in Danish Labrador Retrievers: prevalence and selected risk factors     

Berendt M  Gredal H  Pedersen LG  Alban L  Alving J 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):262-268

The purpose of this study was to investigate the prevalence and selected risk factors of epilepsy, the proportion of dogs with epilepsy in remission, and the types of seizures in Danish Labrador Retrievers. A prospective cross-sectional study of epilepsy was conducted in 1999-2000. The study was carried out in 2 phases in a reference population consisting of 29,602 individuals. In phase 1, 550 dogs were selected by random sampling stratified by year of birth. A telephone interview was used to identify dogs with possible epilepsy. In phase 2, dogs judged during phase 1 as possibly suffering from epilepsy were further subjected to physical and neurologic examination, CBC, blood chemistry, and a questionnaire on seizure phenomenology. Seventeen dogs were diagnosed with epilepsy, yielding a prevalence of 3.1% (95% CI 1.6-4.6%) in the Danish population of Labrador Retrievers. A diagnosis of epilepsy was 6 times more probable in dogs >4 years (born before 1995) than in younger dogs (born between 1995 and 1999) (P = .004, relative risk = 6.5). No significant difference in risk between genders was observed, nor could any effect of neutering be proven statistically. The frequencies of primary generalized seizures and partial seizures (with or without secondary generalization) were 24 and 70%, respectively. The type of seizures could not be classified in 6%. In conclusion, the 3.1% prevalence of epilepsy in Danish Labrador Retrievers is higher than the 1% prevalence of epilepsy described in the general canine population, establishing that this breed is at increased risk.  相似文献