An invasive insect herbivore disrupts plant volatile-mediated tritrophic signalling     

Letizia Martorana  Maria Cristina Foti  Gabriele Rondoni  Eric Conti  Stefano Colazza  Ezio Peri 《Journal of pest science》2017,90(4):1079-1085

Plants respond to insect attack by emission of volatile organic compounds, which recruit natural enemies of the attacking herbivore, constituting an indirect plant defence strategy. In this context, the egg parasitoid Trissolcus basalis is attracted by oviposition-induced plant volatiles emitted by Vicia faba plants as a consequence of feeding and oviposition by the pentatomid host Nezara viridula. However, this local tritrophic web could be affected by the recent invasion by the alien pentatomid bug Halyomorpha halys, an herbivore that shares the same environments as native pentatomid pests. Therefore, we investigated in laboratory conditions the possible impact of H. halys on the plant volatile-mediated signalling in the local tritrophic web V. faba–N. viridula–T. basalis. We found that T. basalis wasps were not attracted by volatiles induced in the plants by feeding and oviposition activities of H. halys, indicating specificity in the wasps’ response. However, the parasitoid attraction towards plant volatiles emitted as a consequence of feeding and oviposition by the associated host was disrupted when host, N. viridula, and non-associated host, H. halys, were concurrently present on the same plant, indicating that invasion by the alien herbivore interferes with established semiochemical webs. These outcomes are discussed in a context of multiple herbivory by evaluating the possible influences of alien insects on local parasitoid foraging behaviour.  相似文献   

Pre‐crop effects of alfalfa management systems on inorganic soil nitrogen and cereals in organic farming under pannonian site conditions     

Renate de Kruijff  Gabriele Pietsch  Bernhard Freyer  Jürgen K. Friedel 《植物养料与土壤学杂志》2008,171(4):576-579

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Pyrrolizidine alkaloid production of Jacobaea aquatica and contamination of forage in meadows of Northern Austria     

Remigius Chizzola  Gabriele Bassler‐Binder  Gerhard Karrer  Monika Kriechbaum 《Grass and Forage Science》2019,74(1):19-28

Jacobaea aquatica (=Senecio aquaticus, Asteraceae), marsh ragwort, grows regionally in low management intensity wet grasslands in various European countries. The plant can be regarded as a noxious weed as it contains pyrrolizidine alkaloids (PAs), which cause health problems in livestock. In the Waldviertel region of Northern Austria, marsh ragwort has established dense populations as the fertilizing and production intensity of the meadows changed during the last decades. Ragwort biomass production and alkaloid concentration in J. aquatica were recorded during three consecutive years at three sites to study the effects of two treatments: cutting twice a year either early in June plus September, or in July plus August, respectively. Six PAs (Z‐erucifoline > senecionine > integerrimine > seneciphylline > acetyl‐erucifoline and acetyl‐seneciphylline) were evaluated. The alkaloid contents were highest in July and August when 600–1,400 mg/kg dry matter (DM) total PAs occurred in most ragwort samples. Consequently, the forage can easily be contaminated with 40–80 mg/kg DM of PAs and may present a health risk for domestic animals and also affect human health as these alkaloids are transferred into milk.  相似文献   

Diagnosis and treatment of arthrosis of cervical articular facet joints in Scottish Deerhounds: 9 cases (1998-2002)     

Kinzel S  Hein S  Buecker A  Krombach GA  Kuepper W 《Journal of the American Veterinary Medical Association》2003,223(9):1311-1315

OBJECTIVE: To determine diagnostic features and efficacy of treatment of arthrosis of the cervical articular facet joints between C2 and C3 in Scottish Deerhounds. DESIGN: Retrospective study. ANIMALS: 9 client-owned dogs. PROCEDURE: Medical records of affected dogs were reviewed. Diagnosis was confirmed by results of clinical examination (signs of severe pain from unilateral or bilateral flexion of the cervical vertebral column), radiography, myelography, and computed tomography. Treatment consisted of fluoroscopy-guided intra-articular injection of corticosteroids and lidocaine. RESULTS: Unilateral or bilateral arthrosis of the cervical facet joints between C2 and C3 was detected in all dogs. In 7 dogs, signs of pain were elicited by flexion of the side of the neck in which affected joints were detected radiographically. Two dogs had signs of pain during right lateral flexion, although bilateral lesions were detected. Five dogs had unilateral lesions, and 4 dogs had bilateral lesions; sclerosis and hypertrophy of the articular process were common. Two dogs had bridging of the articular space. Use of computed tomography confirmed the diagnosis. Myelography did not reveal abnormalities of the spinal cord or canal. After treatment, 8 dogs had rapid marked improvement of clinical signs, and 7 dogs remained free of clinical signs for > 4 months. CONCLUSIONS AND CLINICAL RELEVANCE: Arthrosis of the cervical facet joints in Scottish Deerhounds is a severely painful condition for which conventional radiography is a useful screening test. Intra-articular administration of corticosteroids and anesthetic is efficacious, long-lasting, and minimally invasive.  相似文献   

Oral bleeding associated with pancreatic enzyme supplementation in three dogs with exocrine pancreatic insufficiency     

Rutz GM  Steiner JM  Williams DA 《Journal of the American Veterinary Medical Association》2002,221(12):1716-8, 1714

Three dogs with exocrine pancreatic insufficiency developed oral bleeding during treatment with pancreatic enzyme supplements. According to the owners of the dogs, bleeding from the oral cavity developed during or shortly after consumption of meals containing the pancreatic enzyme supplement. Oral bleeding stopped in all dogs when owners reduced the dose of the pancreatic enzyme supplement. In 2 dogs, the decrease in the dose of the pancreatic enzyme supplement did not affect fecal consistency. However, in the third dog, the decrease in dose led to a recurrence of clinical signs. Findings in these dogs suggest that high doses of pancreatic enzyme supplements can cause oral bleeding in dogs with pancreatic insufficiency, but that oral bleeding can be successfully managed by dose reduction in most dogs.  相似文献   

Differences in wound-induced changes in cell-wall peroxidase activities and isoform patterns between seedlings of Prosopis tamarugo and Prosopis chilensis     

Lehner G  Cardemil L 《Tree physiology》2003,23(7):443-452

We determined changes in cell-wall peroxidase activities and isoform patterns in response to wounding in seedlings of Prosopis tamarugo Phil. (an endemic species of the Atacama Desert) and Prosopis chilensis (Mol.) Stuntz (a native species of central Chile), to assess tolerance to predation. In seedlings of both species, the maximal increase in peroxidase activity occurred 48 h after wounding, reaching three times the control value in P. tamarugo and twice the control value in P. chilensis. The activity of ionically bound cell-wall peroxidases increased only locally in wounded embryonic axes, whereas the activity of soluble peroxidases increased systemically in unwounded cotyledons. Analysis of ionic peroxidases by isoelectrofocusing revealed two groups of peroxidases in the cell walls of both species: four distinct acidic isoforms and a group of basic isoforms. In response to wounding, there was a large increase in activity of the acidic isoforms in P. tamarugo, whereas there was an increase in the activity of the basic isoforms in P. chilensis. In P. chilensis, the wound-induced increase in activity of the basic isoforms corresponded with one of the two isoforms detected in P. tamarugo prior to wounding. Experiments with protein and RNA synthesis inhibitors indicated that a preexisting basic peroxidase is activated in P. chilensis after wounding. Assays of ionically bound peroxidase activity with four different substrates corroborated the differences found in isoform patterns between species. In P. tamarugo, the largest increases in activity were found with ortho-phenylenediamine and ferulic acid as substrates, whereas in P. chilensis the largest increase in activity was found with guaiacol as substrate. Because the same basic cell-wall peroxidase that accumulated after wounding in P. chilensis was present in P. tamarugo prior to wounding, and the activity of acidic cell-wall peroxidases increased after wounding in P. tamarugo but not in P. chilensis, we conclude that P. tamarugo is more tolerant to wound stress than P. chilensis.  相似文献   

Satellite estimate of grass biomass in a mountainous range in central Italy   总被引：1，自引：0，他引：1  

Gabriele Schino  Flavio Borfecchia  Luigi De Cecco  Camilla Dibari  Massimo Iannetta  Sandro Martini  Franco Pedrotti 《Agroforestry Systems》2003,59(2):157-162

One of the main problems in managing ranges used for extensive pastoralism is the difficulty of obtaining reliable estimates of grass biomass over very large areas. Estimates of grass biomass are useful as an indicator of both available forage and risk of soil erosion. Nevertheless, large scale field measurements are expensive and time-consuming. The use of satellite images may provide a complementary means of estimating grass biomass over very large areas at a reasonable cost. The aim of this study was to test the use of Landsat satellite data for estimating grass biomass in a mountainous range in central Italy used primarily for sheep breeding. During each of four ground campaigns carried out over two years, grass was cut and its biomass measured in 60-90 test plots. Four Landsat images taken simultaneously to the ground campaigns were processed to obtain several vegetation indexes calculated for each ground test plot. The vegetation indexes showed significant correlations with measured grass biomass. The Normalized Difference Vegetation Index (NDVI) provided the most accurate estimate of grass biomass. When data for each of the four ground campaigns were analyzed separately, correlations for early summer campaigns were higher than correlations for late summer campaigns, indicating that when the ratio of dry/green biomass increases, satellite estimate becomes less accurate. Overall, our results show that satellite data can provide a useful source of biomass information for the management of large ranges. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Evaluation of biological safety in vitro and immunogenicity in vivo of recombinant Escherichia coli Shiga toxoids as candidate vaccines in cattle     

Katharina Kerner  Philip S Bridger  Gabriele K?pf  Julia Fr?hlich  Stefanie Barth  Hermann Willems  Rolf Bauerfeind  Georg Baljer  Christian Menge 《Veterinary research》2015,46(1)

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Effect of CaCl2 on the kinetics of dissolved organic matter release from a sandy soil�     

Gabriele E. Schaumann 《植物养料与土壤学杂志》2000,163(5):523-529

The dissolution of organic matter in soil is of fundamental relevance for the fate of organic contaminants associated with organic matter and for the microbial availability of organic matter. In this study, the kinetics of soil organic matter (SOM) dissolution from a sandy forest soil was investigated under different electrolyte conditions, using a continuous extraction method. The mathematical analysis of the concentration signal obtained from extractions with constant flow rates and after sudden flow rate changes showed that the dissolution of SOM is diffusion limited. The dissolution rate was lower during extraction with 0.01 M CaCl₂. The reaction on sudden flow rate changes was slower when extracting with 0.01 M CaCl₂ as compared to water, and the mechanism was different. These observations were explained by a gel phase developing in the swelling SOM. The lower dissolution rates found for extractions with 0.01 M CaCl₂ could indicate a more stable gel structure in the presence Ca²⁺. The development of the gel phase may be influenced by mechanical strain due to increased flow rates.  相似文献   

The influence of chemical soil factors on the development of VA mycorrhizas of ash (Fraxinus excelsior L.) and sycamore(Acer pseudoplatanus L.) in pot experiments     

Gabriele Weber  Marion Claus 《植物养料与土壤学杂志》2000,163(6):609-616

The objectives of this study were (1) to investigate effects of soil acidity on the formation of mycorrhizas in ash and sycamore, and (2) to elucidate if mycorrhization can improve the acquisition of Ca, Mg, and P by these tree species. Soil substrates with different Ca, Mg, and Al saturation were used in pot experiments with mycorrhizal ash and sycamore seedlings and various Ca and Mg fertilization treatments. The development of vesicular‐arbuscular‐mycorrhizas (VAM) in both species was considerably affected by the chemical soil properties and by the nutritional status of the plants. Mycorrhizal fungi developed well only in plants growing on basalt‐derived, Ca and Mg rich loam and in substrates fertilized with Ca and Mg carbonate. In these substrates, the pH value, Ca and Mg supply and growth of the plants were optimal. The mycorrhizas degenerated in an acid loam derived from phyllite, in tertiary sand and in all treatments receiving Ca and Mg sulfate. Ash and sycamore suffered from Ca and Mg (P) deficiency, and partly from Al antagonism against Ca and Mg uptake (sycamore) or Al toxicity (ash). The symbiosis between fungi and the plants was disrupted since the tree species and the VAM fungi (from fertile nursery soils) did not adapt to the acidic experimental soil substrates with high Al activity. Consequently, the fungi lost their function of supporting the plants by improved nutrient uptake and the plants likely did not produce enough organic substances for the fungi. In addition, N fertilization possibly suppressed the development of VA mycorrhizas and inhibited new colonization in acid substrates.  相似文献