Application of an electrophoretically detectable genetic marker to ploidy testing in brown trout (Salmo trutta L.) triploidised by heat shock     

Walter W. Crozier  Ian J.J. Moffett 《Aquaculture (Amsterdam, Netherlands)》1989,80(3-4):231-239

A phosphoglucose isomerase (PGI) variant, of brown trout (Salmo trutta L.), expressed in adipose fin tissue, was incorporated into experimental batches through selective crossing of brood-stock having the PGI-3 (110) marker gene. PGI-3 (110) homozygous females were crossed with PGI-3 (100) homozygous males to yield all PGI-3 (110/100) progeny. These were subject to heat shock for 10 min at 28°C, commencing 10 min after insemination. Electrophoretic examination of fry indicated that diploids and triploids were separable on the basis of PGI-3 banding patterns, having staining ratios of 1:2:1 and 4:4:1, respectively. This confirmed the retention of an extra maternal PGI-3 (110) gene in triploid individuals. Potential applications of this marker in triploid studies in brown trout are discussed.  相似文献   

Minimizing instrumentation requirement for estimating crop water stress index and transpiration of maize     

Saleh Taghvaeian  José L. Chávez  Walter C. Bausch  Kendall C. DeJonge  Thomas J. Trout 《Irrigation Science》2014,32(1):53-65

Research was conducted in northern Colorado in 2011 to estimate the crop water stress index (CWSI) and actual transpiration (T _a) of maize under a range of irrigation regimes. The main goal was to obtain these parameters with minimum instrumentation and measurements. The results confirmed that empirical baselines required for CWSI calculation are transferable within regions with similar climatic conditions, eliminating the need to develop them for each irrigation scheme. This means that maize CWSI can be determined using only two instruments: an infrared thermometer and an air temperature/relative humidity sensor. Reference evapotranspiration data obtained from a modified atmometer were similar to those estimated at a standard weather station, suggesting that maize T _a can be calculated based on CWSI and by adding one additional instrument: a modified atmometer. Estimated CWSI during four hourly periods centered on solar noon was largest during the 2 h after solar noon. Hence, this time window is recommended for once-a-day data acquisition if the goal is to capture maximum stress level. Maize T _a based on CWSI during the first hourly period (10:00–11:00) was closest to T _a estimates from a widely used crop coefficient model. Thus, this time window is recommended if the goal is to monitor maize water use. Average CWSI over the 2 h after solar noon and during the study period (early August to late September, 2011) was 0.19, 0.57, and 0.20 for plots under full, low-frequency deficit, and high-frequency deficit irrigation regimes, respectively. During the same period (50 days), total maize T _a based on the 10:00–11:00 CWSI was 218, 141, and 208 mm for the same treatments, respectively. These values were within 3 % of the results of the crop coefficient approach.  相似文献   

Performance of soil-applied FeEDDHA isomers in delivering Fe to soybean plants in relation to the moment of application     

Schenkeveld WD  Reichwein AM  Bugter MH  Temminghoff EJ  van Riemsdijk WH 《Journal of agricultural and food chemistry》2010,58(24):12833-12839

FeEDDHA (iron(3+) ethylenediamine-N,N'-bis(hydroxyphenylacetic acid) products are commonly applied to mend and prevent Fe deficiency chlorosis in soil-grown crops. Plants mainly take up Fe in the progressed vegetative and in the reproductive stages. This study examined which of the principal constituents of FeEDDHA products (the isomers racemic o,o-FeEDDHA, meso o,o-FeEDDHA, and o,p-FeEDDHA), most effectively meets the Fe requirements of soybean plants (Glycine max (L.) Merr.) grown on calcareous soil in the aforementioned growth stages. FeEDDHA isomers were applied once, separately or in mixtures, at t = 0, in the progressed vegetative stage or in the reproductive stage. o,p-FeEDDHA did not significantly contribute to Fe uptake in either growth stage. Both racemic and meso o,o-FeEDDHA were effective in supplying plants with Fe, approximately to the same extent. The moment of application had a significant effect on yield and FeEDDHA pore water concentrations at harvest, but not on Fe uptake. To optimize yield while minimizing FeEDDHA dosage, FeEDDHA is best applied to soybean plants prior to the onset of chorosis.  相似文献   

Investigating the mechanisms for the opposing pH relationships of fungal and bacterial growth in soil     

Johannes Rousk  Philip C. Brookes 《Soil biology & biochemistry》2010,42(6):926-934

Soil pH is one of the most influential variables in soil, and is a powerful factor in influencing the size, activity and community structure of the soil microbial community. It was previously shown in a century old artificial pH gradient in an arable soil (pH 4.0-8.3) that bacterial growth is positively related to pH, while fungal growth increases with decreasing pH. In an attempt to elucidate some of the mechanisms for this, plant material that especially promotes fungal growth (straw) or bacterial growth (alfalfa) was added to soil samples of the pH gradient in 5-day laboratory incubation experiments. Also, bacterial growth was specifically inhibited by applying a selective bacterial growth inhibitor (bronopol) along the entire pH gradient to investigate if competitive interaction caused the shift in the decomposer community along the gradient. Straw benefited fungal growth relatively more than bacterial, and vice versa for alfalfa. The general pattern of a shift in fungal:bacterial growth with pH was, however, unaffected by substrate additions, indicating that lack of a suitable substrate was not the cause of the pH effect on the microbial community. In response to the bacterial growth inhibition by bronopol, there was stimulation of fungal growth up to pH 7, but not beyond, both for alfalfa and straw addition. However, the accumulation of ergosterol (an indicator of fungal biomass) during the incubation period after adding alfalfa increased at all pHs, indicating that fungal growth had been high at some time during the 5-day incubation following joint addition of alfalfa and bronopol. This was corroborated in a time-series experiment. In conclusion, the low fungal growth at high pH in an arable soil was caused to a large extent by bacterial competition, and not substrate limitation.  相似文献   

Loss of low molecular weight dissolved organic carbon (DOC) and nitrogen (DON) in H₂O and 0.5 M K₂SO₄ soil extracts     

Johannes Rousk  Davey L. Jones 《Soil biology & biochemistry》2010,42(12):2331-2335

Soil extracts are routinely used to quantify dissolved organic nutrient concentrations in soil. Here we studied the loss and transformation of low molecular weight (LMW) components of DOC (¹⁴C-glucose, 1 and 100 μM) and DON (¹⁴C-amino acid mixture, 1 and 100 μM) during extraction of soil (0-6 h) with either distilled water or 0.5 M K₂SO₄. The extractions were performed at 20 °C, at 4 °C, or in the presence of an inhibitor of microbial activity (HgCl₂ and Na-azide). We showed that both glucose and amino acids became progressively lost from solution with increasing shaking time. The greatest loss was observed in H₂O extracts at 1 μM for both substances (>90% loss after 15 min). Lower temperature (4 °C) and presence of K₂SO₄ both resulted in reduced loss rates. The presence of microbial inhibitors effectively eliminated the loss of glucose and amino acids. We conclude that microbial transformation of LMW-DOC and DON during H₂O or K₂SO₄ extraction of soil may affect the estimation of their concentrations in soil. This finding has significant implications for methods that rely on chemical extractions to estimate LMW-C components of DOC and DON.  相似文献   

Der Einfluß hoher N-Gaben auf die zellulolytische Aktivität des Bodens sowie Beziehungen zwischen Mikroorganismentätigkeit und Ertragsleistung einer Weide     

Horst Unger 《Archives of Agronomy and Soil Science》2013,59(1-3):215-232

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Cellulose acetate electrophoresis of canine plasma after fibrinogen precipitation by ethanol     

Silvia Rossi  Walter Bertazzolo  Saverio Paltrinieri  Alessia Giordano 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2008,37(4):422-428

Background: In routine canine medicine, anticoagulated blood is often the only sample sent to laboratories for diagnostic purposes. This hampers the interpretation of protein electrophoretic tracings because plasma contains fibrinogen, which migrates in the β–γ region. In human medicine, fibrinogen can be precipitated from plasma using ethanol. Objectives: The purpose of this study was to assess ethanol precipitation as a method for removing fibrinogen from canine plasma so as to facilitate the interpretation of electorphoresis results. Methods: Blood samples collected from 40 dogs were divided into plain tubes and tubes containing EDTA (n=20) or lithium–heparin (n=20). An aliquot of plasma from each sample was incubated with ethanol at a final concentration of 100 mL/L. Cellulose acetate electrophoresis was then performed on serum, plasma, and plasma treated with ethanol. To verify the efficiency of ethanol treatment, fibrinogen was added to 5 canine serum samples at final concentrations of 2.5, 5.0, and 10.0 g/L, and electrophoresis was performed before and after ethanol treatment. Results: Visual analysis of electrophoretograms from ethanol‐treated samples confirmed the disappearance of the fibrinogen peak from the β₂‐globulin region. Treatment with ethanol caused a significant decrease in the percentage of β₂‐globulins and a significant increase in the percentage of α₂‐globulins. Absolute values of most electrophoretic fractions were significantly decreased in ethanol‐treated plasma compared with serum. Conclusions: Ethanol treatment successfully removed fibrinogen from canine plasma and normalized electrophoretic profiles, but probably also precipitated proteins other than fibrinogen. Ethanol treatment is recommended to facilitate visual identification of abnormal monoclonal peaks, but not for determining absolute protein concentrations in electrophoretic fractions.  相似文献   

Korrelationen zwischen den Werten der Saugkraft,der Zellsaftkonzentration und des Feuchtegehaltes in Zuckerrübenblättern und die Abhängigkeit der Zellsaftkonzentration von der Luft- und Bodenfeuchtigkeit     

Johannes Birke 《Archives of Agronomy and Soil Science》2013,59(12):1041-1049

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Langjähriger witterungseinfluss auf das grünland in zwei verschiedenen landschaftsgebieten     

Wolfgang Leipnitz  Horst Käding  Gisbert Schalitz 《Archives of Agronomy and Soil Science》2013,59(4):283-289

Langjährige Beobachtungen der Witterungsfaktoren Temperatur und Niederschlag auf Ertrag und Pflanzenbestand von zwei Dauergrünlandstandorten verschiedener Klimagebiete wurden ausgewertet. Anlaß war das Phänomen, daß im Erzgebirge der Ertrag trotz hoher Stickstoffdungung nach dem 3. Versuchsjahr sukzessive abfiel und nach dem 12. Jahr wieder anstieg. Als Vergleich bot sich nahezu gleich bewirtschaftetes Grünland im Havelländischen Luch an.

Die Ursache fur die Ertragsdepression wurde zunächst in einer Umschichtung der Pflanzenbestände vermutet. Schließlich wurde ein Zusammenhang zwischen Witterung und Ertrag am Beispiel der Abweichungen von den Mittelwerten gefunden.  相似文献   

Autorreferate demnächst erscheinender Arbeiten     

Johannes Birke 《Archives of Agronomy and Soil Science》2013,59(9):679-682

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