Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis   总被引：1，自引：0，他引：1  

Heiner Flessa  Wulf Amelung  Mirjam Helfrich  Guido L. B. Wiesenberg  Gerd Gleixner  Sonja Brodowski  Janet Rethemeyer  Christiane Kramer  Pieter M. Grootes 《植物养料与土壤学杂志》2008,171(1):36-51

Quantitative information about the amount and stability of organic carbon (OC) in different soil organic‐matter (OM) fractions and in specific organic compounds and compound‐classes is needed to improve our understanding of organic‐matter sequestration in soils. In the present paper, we summarize and integrate results performed on two different arable soils with continuous maize cropping (a) Stagnic Luvisol with maize cropping for 24 y, b) Luvic Phaeozem with maize cropping for 39 y) to identify (1) the storage of OC in different soil organic‐matter fractions, (2) the function of these fractions with respect to soil‐OC stabilization, (3) the importance and partitioning of fossil‐C deposits, and (4) the rates of soil‐OC stabilization as assessed by compound‐specific isotope analyses. The fractionation procedures included particle‐size fractionation, density fractionation, aggregate fractionation, acid hydrolysis, different oxidation procedures, isolation of extractable lipids and phospholipid fatty acids, pyrolysis, and the determination of black C. Stability of OC was determined by ¹³C and ¹⁴C analyses. The main inputs of OC were plant litter (both sites) and deposition of fossil C likely from coal combustion and lignite dust (only Phaeozem).  相似文献   

Analysis of genetic diversity in a sweet potato (Ipomoea batatas L.) germplasm collection from Tanzania as revealed by AFLP     

Abdelhameed Elameen  Siri Fjellheim  Arild Larsen  Odd Arne Rognli  Leif Sundheim  Susan Msolla  Esther Masumba  Kiddo Mtunda  Sonja S. Klemsdal 《Genetic Resources and Crop Evolution》2008,55(3):397-408

Sweet potato (Ipomoea batatas L.) is the fifth most important crop in the developing countries after rice, wheat, maize and cassava. The amplified fragment length polymorphism (AFLP) method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection of Sokoine University of Agriculture, Morogoro and Sugarcane Research Institute, Kibaha, Tanzania. AFLP analysis of 97 sweet potato accessions using ten primer combinations gave a total of 202 clear polymorphic bands. Each one of the 97 sweet potato accessions could be distinguished based on these primer combinations. Estimates of genetic similarities were obtained by the Dice coefficient, and a final dendrogram was constructed with the un-weight pair-group method using arithmetic average. AFLP-based genetic similarity varied from 0.388 to 0.941, with a mean of 0.709. Cluster analysis using genetic similarity divided the accessions into two main groups suggesting that there are genetic relationships among the accessions. Principal Coordinate analysis confirmed the pattern of the cluster analysis. Analysis of molecular variance revealed greater variation within regions (96.19%) than among regions (3.81%). The results from the AFLP analysis revealed a relatively low genetic diversity among the germplasm accessions and the genetic distances between regions were low. A maximally diverse subset of 13 accessions capturing 97% of the molecular markers diversity was identified. We were able to detect duplicates accessions in the germplasm collection using the highly polymorphic markers obtained by AFLP, which were found to be an efficient tool to characterize the genetic diversity and relationships of sweet potato accessions in the germplasm collection in Tanzania.  相似文献   

Selection of cowpea genotypes based on grain mineral and total protein content     

Abe Shegro Gerrano  Willem S. Jansen van Rensburg  Sonja L. Venter  Nemera G. Shargie  Beyene A. Amelework  Hussein A. Shimelis 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(2):155-166

Grain legumes, including cowpea, are the cheapest sources of minerals and protein to enhance human nutrition. Cultivar development and deployment of cowpea with increased grain mineral content and protein composition rely on selection of genetically unique and complementary breeding lines. The objective of this study was to assess the grain minerals and protein composition of diverse cowpea collections of eastern, southern and western Africa to select promising parents to develop a breeding population. Twenty-two genetically diverse cowpea genotypes were field evaluated using a randomised complete block design with three replications in two locations in South Africa. The dried grain mineral contents were determined using an Atomic Absorption Spectrophotometre, while the protein content was determined by the combustion method. Analyses of variance showed significant (P?<?0.05) effects of genotypes, locations and their interactions. The test genotypes showed considerable variation for the following nine mineral contents: calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), and zinc (Zn) varying from 0.07 to 0.12?mg?kg^?1; 4.46 to 7.81?mg?kg^?1; 0.06 to 0.11?g; 11.82 to 14.45?g; 1.86 to 2.27?g; 9.24 to 13.30?mg?kg^?1; 0.26 to 0.80?g; 4.63 to 5.92?g and 0.03.00 to 0.05?g, respectively. Further, the total protein content varied from 23.16 to 28.13%. Significant correlations were detected among some mineral elements and total protein content, suggesting the possibility of simultaneous selection for these traits. The principal component analysis (PCA) identified four principal components (PCs) contributing to 70.93% of the total explained variation amongst genotypes. Overall the following genotypes with desirable grain mineral and protein attributes were selected: IT90K-59 (Ca), 98K-5301 (Ca and protein), ITOOK-1060 (Cu), ITOOK-1217 and IT845-2246 (Fe), Bensogla (K, Na, and P), TVU11424 and ITOOK-1217 (Mg), CH14 (Mn and Na), TVU12637 (Mn) and Glenda and Vuli (Zn). The selected cowpea genotypes are useful genetic resources for population and cultivar development for grain nutrients composition.  相似文献   

Parasites of cultured and wild brown‐marbled grouper Epinephelus fuscoguttatus (Forsskål, 1775) in Lampung Bay,Indonesia     

Sonja Rückert  Sven Klimpel  Harry Wilhelm Palm 《Aquaculture Research》2010,41(8):1158-1169

A total of 210 Epinephelus fuscoguttatus (brown‐marbled grouper) was examined for parasites. During three consecutive seasons (two rainy and one dry season from 2002 to 2004), 35 specimens each taken from floating net cages of the National Sea Farming Development Centre (Balai Budidaya Laut) and from wild catches in Lampung Bay, South Sumatra, Indonesia were studied. Twenty‐five (cultured grouper) and 30 (wild grouper) parasite species/taxa were identified, with an infracommunity ranging from one to nine (cultured) and three to 14 parasite species (wild), demonstrating a species‐rich parasite fauna even in the cultured fish. Protozoans (1 species), microsporeans (1), myxozoans (1), digeneans (8), monogeneans (5), cestodes (3), nematodes (8), acanthocephalans (2) and crustaceans (6) were found. The most abundant parasites were the monogeneans Pseudorhabdosynochus epinepheli and Pseudorhabdosynochus lantauensis for both, cultured and wild grouper during all seasons. For the cultured fish, the prevalence of monoxenous ectoparasites (e.g. P. epinepheli, P. lantauensis, Capsalidae gen. et sp. indet., Benedenia epinepheli) was in most cases higher than that of heteroxenous endoparasites. This contrasts the wild grouper, where heteroxenous parasites such as Allopodocotyle epinepheli and Raphidascaris sp. occurred at a similar prevalence compared with the fairly abundant Pseudorhabdosynochus spp. No seasonality of infestation was observed for both cultured and wild fish. The high levels of infestation of potentially pathogenic monogeneans throughout the year could result in significant parasite outbreaks at the locality studied.  相似文献   

Cystoscopy in cattle--a valuable additional tool for clinical examination     

Franz S  Winter P  Baumgartner W 《Acta veterinaria Hungarica》2004,52(4):423-438

Based on the findings of physical examination and on laboratory findings the urinary bladder of 23 cows was examined endoscopically in order to investigate the application of cystoscopy in cattle. The endoscopic findings of all examined cows were compared with the findings of physical examination and the results of macroscopic and microscopic urinalysis and the bacteriological culture of the urine. By physical examination only 3 cows were diagnosed to have urinary tract disease, whereas all other cows were suspected of having an urinary tract disease. Bacteriological culture of the urine revealed Corynebacterium renale and Escherichia coli infection in 18 cows, while the remaining 5 cows were negative. By cystoscopy catarrhal cystitis was diagnosed in 2 cases, haemorrhagic cystitis in 5 cases, and fibrinous-purulent and fibrinous-haemorrhagic cystitis in 13 cases. Three cows showed no pathological changes of the urinary bladder mucosa by endoscopic examination. Cystoscopy facilitates diagnosis through the direct visualisation of mucosal lesions and makes it possible to give a more accurate prognosis based upon the findings.  相似文献   

Use of endoscopy for examination of the sacral epidural space in standing cattle     

Franz S  Dadak AM  Moens Y  Baumgartner W  Iff I 《American journal of veterinary research》2008,69(7):894-899

OBJECTIVE: To develop an epiduroscopic technique for use in standing cattle and describe the endoscopically visible anatomic structures of the epidural space in the sacrococcygeal area. ANIMALS: 6 healthy nonlactating, nonpregnant cows (mean +/- SD age, 60 +/- 18.5 months; mean weight, 599.7 +/- 63.87 kg) and 3 bovine cadavers. PROCEDURES: Cadavers were used to allow familiarization with the equipment and refinement of the technique. Following these experiences, procedures were performed in live animals. Each cow was restrained in a stock. After sedation with xylazine (0.03 mg/kg, IV), 2% lidocaine hydrochloride (0.25 mg/kg) was injected epidurally in the first intercoccygeal or the sacrococcygeal intervertebral space. By use of an introducer set (guidewire and dilation trocar and shaft), a flexible endoscope (length, 75 cm; diameter, 2.3 mm) was inserted through the dilation shaft into the epidural space. To obtain an optimal view, small amounts of air were insufflated into the epidural space through the working channel of the endoscope via a syringe with special filter. RESULTS: Anatomic structures of the epidural space that were viewed by means of the endoscopic procedure included blood vessels, connective tissue, fat, nerves, and the spinal dura mater. No adverse events were detected during epiduroscopy, and it was tolerated well by all 6 cows. CONCLUSIONS AND CLINICAL RELEVANCE: In ruminants, epidural structures can be viewed via endoscopy. Such epiduroscopic procedures may be useful in anatomic studies as well as for the diagnosis of disease or therapeutic interventions in ruminants.  相似文献   

IMAGING DIAGNOSIS—THE COMPUTED TOMOGRAPHIC APPEARANCE OF A GIANT CELL TUMOR AFFECTING THE MANDIBLE IN A PYGMY GOAT          下载免费PDF全文

Jonathon Dixon  Renate Weller  Sonja Jeckel  Roy Pool  Alex Mcsloy 《Veterinary radiology & ultrasound》2016,57(5):E51-E53

A 3‐year‐old male neutered pygmy goat presented for evaluation of a progressive mandibular swelling and inappetence. A computed tomographic (CT) scan of the head and thorax was performed under general anesthesia. Computed tomography revealed an extensive multiloculated, markedly expansile lesion within the right hemimandible, which involved the articular surface of the temporomandibular joint. The goat was euthanased due to a poor prognosis and postmortem examination confirmed the diagnostic imaging findings. Histopathology was strongly suggestive of a multinucleated giant cell tumor, therefore this condition should be considered as a differential diagnosis in goats presenting with expansile mandibular mass lesions.  相似文献   

Septic keratitis in dogs,cats, and horses in Switzerland: associated bacteria and antibiotic susceptibility          下载免费PDF全文

Anja Suter  Katrin Voelter  Sonja Hartnack  Bernhard Martin Spiess  Simon Anton Pot 《Veterinary ophthalmology》2018,21(1):66-75

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Influence of litter chemistry and stoichiometry on glucan depolymerization during decomposition of beech (Fagus sylvatica L.) litter     

Leitner S  Wanek W  Wild B  Haemmerle I  Kohl L  Keiblinger KM  Zechmeister-Boltenstern S  Richter A 《Soil biology & biochemistry》2012,50(6):174-187

Glucans like cellulose and starch are a major source of carbon for decomposer food webs, especially during early- and intermediate-stages of decomposition. Litter quality has previously been suggested to notably influence decomposition processes as it determines the decomposability of organic material and the nutrient availability to the decomposer community. To study the impact of chemical and elemental composition of resources on glucan decomposition, a laboratory experiment was carried out using beech (Fagus sylvatica, L.) litter from four different locations in Austria, differing in composition (concentration of starch, cellulose and acid unhydrolyzable residue or AUR fraction) and elemental stoichiometry (C:N:P ratio). Leaf litter was incubated in mesocosms for six months in the laboratory under controlled conditions. To investigate the process of glucan decomposition and its controls, we developed an isotope pool dilution (IPD) assay using (13)C-glucose to label the pool of free glucose in the litter, and subsequently measured the dilution of label over time. This enabled us to calculate gross rates of glucose production through glucan depolymerization, and glucose consumption by the microbial community. In addition, potential activities of extracellular cellulases and ligninases (peroxidases and phenoloxidases) were measured to identify effects of resource chemistry and stoichiometry on microbial enzyme production. Gross rates of glucan depolymerization and glucose consumption were highly correlated, indicating that both processes are co-regulated and intrinsically linked by the microbial demand for C and energy and thereby to resource allocation to enzymes that depolymerize glucans. At early stages of decomposition, glucan depolymerization rates were correlated with starch content, indicating that starch was the primary source for glucose. With progressing litter decomposition, the correlation with starch diminished and glucan depolymerization rates were highly correlated to cellulase activities, suggesting that cellulose was the primary substrate for glucan depolymerization at this stage of decomposition. Litter stoichiometry did not affect glucan depolymerization or glucose consumption rates early in decomposition. At later stages, however, we found significant negative relationships between glucan depolymerization and litter C:N and AUR:N ratio and a positive relationship between glucan depolymerization and litter N concentration. Litter C:N and C:P ratios were negatively related to cellulase, peroxidase and phenoloxidase activities three and six months after incubation, further corroborating the importance of resource stoichiometry for glucan depolymerization after the initial pulse of starch degradation.  相似文献   

Predictive modelling of interventions to improve iodine intake in New Zealand     

Schiess S  Cressey PJ  Thomson BM 《Public health nutrition》2012,15(10):1932-1940

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