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22.
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
23.
The interest in organic grown cereals has increased the need for variety tests under organic growing systems and/or the knowledge
on whether growth characteristics describe yield differently under conventional and organic conditions. This paper is a contribution
to that question by examining the relationships between some important growth characteristics in barley trials in both systems
in Northern Sweden and in Denmark. Mixed model analyses were used for regressions of growth characteristics (or transformations
of those) on yield (and log-transformed yield), allowing the slope to depend on the growing system. The analyses showed that
diseases seemed to have a less negative effect on yield in the organic growing system than in the conventional growing system
if pesticides were not applied. For other characteristics the effect depended on the country. This was the case for grain
characteristics where the effect of volume weight in the Swedish trials was much larger in the conventional growing system
than in the organic growing system, while a non-significant difference in the opposite direction was found for the trails
from Denmark. For the trials from Denmark the effect of grain weight was much larger in the organic growing system than in
the conventional growing system, but there was only a small and non-significant difference in the Swedish trials. In both
countries there was a significant interaction between the two grain characteristics. 相似文献
24.
Performance evaluation and validation of the animal trauma triage score and modified Glasgow Coma Scale with suggested category adjustment in dogs: A VetCOT registry study 下载免费PDF全文
25.
Margrethe Askegaard Jørgen Berntsen Mogens S. Hovmøller Kristian Kristensen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(5):421-430
Abstract In order to obtain a high and stable yield of organic spring barley, production should be optimized according to the specific environment. To test the performance of spring barley varieties under varying cropping conditions, a field experiment was carried out in 2003 and 2004 in a six-field mixed organic crop rotation. We investigated the choice of variety, the order in a rotation, and the application of manure (slurry and farmyard manure; 0 to 120 total-N ha?1) on grain yields of six selected varieties with different characteristics grown in either pure stands or in two spring barley mixtures, each consisting of three varieties. Average grain yield of the barley varieties varied between 3.3 t DM ha?1 and 4.1 t DM ha?1. Grain yields of the two mixtures were 4.0 and 3.6 t DM ha?1, respectively. The varieties/mixtures interacted with crop order and year. Foliar diseases were more severe in the barley following grass-clover with large annual differences in the individual diseases. Despite different rooting depths and nutrient uptake patterns, there was no interaction between variety/mixture and the manure input regarding grain yield. In the 1st year after grass-clover, one of the two mixtures gave higher grain yield than the average yield of the individual varieties in the mixture. This was not the case in the 4th year after grass-clover and for the second variety mixture. Thus, although the present results did not indicate that some barley varieties were better adapted to conditions with low manure input than others, variety mixtures that give a robust and stable organic production may potentially be developed. 相似文献
26.
Kreysing M Pusch R Haverkate D Landsberger M Engelmann J Ruiter J Mora-Ferrer C Ulbricht E Grosche J Franze K Streif S Schumacher S Makarov F Kacza J Guck J Wolburg H Bowmaker JK von der Emde G Schuster S Wagner HJ Reichenbach A Francke M 《Science (New York, N.Y.)》2012,336(6089):1700-1703
Despite their diversity, vertebrate retinae are specialized to maximize either photon catch or visual acuity. Here, we describe a functional type that is optimized for neither purpose. In the retina of the elephantnose fish (Gnathonemus petersii), cone photoreceptors are grouped together within reflecting, photonic crystal-lined cups acting as macroreceptors, but rod photoreceptors are positioned behind these reflectors. This unusual arrangement matches rod and cone sensitivity for detecting color-mixed stimuli, whereas the photoreceptor grouping renders the fish insensitive to spatial noise; together, this enables more reliable flight reactions in the fish's dim and turbid habitat as compared with fish lacking this retinal specialization. 相似文献
27.
Nawwar MA Ayoub NA El-Rai MA Bassyouny F Mostafa ES Al-Abd AM Harms M Wende K Lindequist U Linscheid MW 《Fitoterapia》2012,83(7):1256-1266
Three ellagitannins and one disulfated flavonol were isolated from the aerial parts of Reaumuria vermiculata L. Besides that, 16 known compounds were characterized as well. The structures of all compounds were elucidated on the basis of spectroscopic data including 1D and 2D NMR and ESI HR-FTMS. The in vivo antioxidant activity using the oxygen radical absorbance capacity (ORAC) method, of the extract, its column fractions and two of the isolated ellagitannins was accomplished. In addition, a possible cytotoxicity of the extract and two of the new ellagitannins on HaCaT human keratinocytes and the activity of both compounds against the prostate cancer cell line (PC-3) were also assessed, whereby a potent cytotoxicity with IC(50) less than 1μg/ml was determined for both compounds. Besides, the extract exhibited a potential cytotoxic effect against four different solid tumor cell lines, namely liver (Huh-7), colorectal (HCT-116), breast (MCF-7) and prostate (PC-3). The IC(50)s were found to be substantially low (ranged from 1.3±0.15 to 2.4±0.22μg/ml) with relatively low resistance possibility reaching to 0% in the case of Huh-7 cell. 相似文献
28.
Data from five 3-year experiments comparing different strategies of non-chemical weed control were analysed in order to set up a model that could be used for simulating further strategies. The treatments included different frequencies and effects of weed control using flaming, steaming and weed brushing. Each plot consisted of about 100 m of sidewalk. The amount of weed on the sidewalks was recorded several times during the 3-year period using a system of cameras mounted on a Terrain Vehicle moving on the sidewalk and post processing using image analyses of extracted images. The percentage of sidewalk covered by weed was estimated on the basis of the image analyses. The model used for describing the weed coverage comprises three components. The first component describes the growth of weeds; the second describes reduction caused by wearing and decay of weeds in the autumn and the third describes the reduction caused by weed control using weed brushing, steaming and flaming. The parameters of the model were estimated from the data for later use for simulating additional strategies. 相似文献
29.
The microbiota of pigs influenced by diet texture and severity of Lawsonia intracellularis infection
Mølbak L Johnsen K Boye M Jensen TK Johansen M Møller K Leser TD 《Veterinary microbiology》2008,128(1-2):96-107
Pigs with and without naturally occurring Lawsonia intracellularis infection were fed diets with different texture. In a previous study from 79 pig herds using a similar feeding on pelleted or non-pelleted form showed that the non-pelleted diet was associated with a reduced prevalence of L. intracellularis. In this study a mechanistic approach was taken for explaining and testing this observation by studying the microbiota and the occurrence of L. intracellularis in the distal ileum of 54 pigs by terminal restriction fragment length polymorphism (T-RFLP) analysis, Real-Time PCR and in situ hybridization. The texture of the diet influenced the microbiota, and from a quantitative discriminative analysis of the terminal restriction fragments (T-RFs) of ileum samples it was deduced that Clostridium spp. and Lactobacillus spp. were associated with the non-pelleted diet and Streptococcus spp. with the pelleted diet. In experimentally infected pigs it was verified that 89bp and 90bp sized T-RFs (HhaI) from ileum represented L. intracellularis. The non-pelleted diet seemed to reduce the relative amount of L. intracellularis in the total microbiota of the ileum, but the number of pigs detected positive with L. intracellularis by Real-Time PCR was not influenced. The five pigs with highest L. intracellularis content showed T-RFs that were not present in profiles from less or non-infected pigs, which may indicate that some bacterial species were associated with L. intracellularis infection. 相似文献
30.
Tore Sivertsen Wenche Langseth Elisabet Mo Kristian Ingebrigtsen 《Acta veterinaria Scandinavica》1993,34(2):227
4-methylimidazole (4-MeI) is up to now the main tremorogenic poison known to be present in ammoniated roughages. The concentration of 4-MeI is widely used as an indicator of the potential toxicity of individual batches of ammoniated straw and hay. 相似文献