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21.
Abstract A commercially blended 7–2–11 fertilizer containing 27 g ? kg‐1 soluble ammoniacal nitrogen (NH4‐N) was evaluated for ammonia (NH3) volatilization and injury to leatherleaf fern (Rumohra adiantiformis) and an indicator plant, tomato (Lycopersicon esculentum). Closed system laboratory incubation studies on pH‐buffered sand medium indicated a very highly significant response (p≤0.001) of NH3 volatilization to sand pH. The greatest risk from NH3 emissions at pH 8.6 and 32°C appeared to be in the 5 to 70 hour period after fertilizer application. Gypsum (CaSO4) did not affect NH3 volatilization. Ammonium nitrate (NH4NO3) was identified as the main source of NH3 volatilization from this fertilizer formulation, while on an equal mass basis, ammonium sulphate [(NH4)2SO4] was more important. Both tomato and immature leatherleaf fern fronds were highly sensitive to volatilized NH3 from the fertilizer. A critical phytotoxic NH3(aq) concentration in sand solution of 0.14 mM was estimated for immature fern fronds. Mature fern fronds were significantly more tolerant of NH3 emissions, which may explain their observed resistance to NH3 injury in the field. Assessment of selected soil and irrigation water pH's from a leatherleaf fern growing area in Florida indicated a strong likelihood that volatilized NH3 injury to foliage can occur under field conditions. 相似文献
22.
Exogenous N-secretion of the pancreas was investigated with growing pigs with fistulae in the pancreas. For this purpose the two protein sources toasted and untoasted soybean oilmeal were used. After the feeding of untoasted soybean oilmeal a significant increase of the secretion volume and of protein outpour could be observed in contrast to toasted soybean oilmeal within 24 h. The heat-labile soybean trypsin inhibitor also caused an activity increase of the pancreatic enzymes. 相似文献
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Speltoid spikes are characterized by pyramidal spike morphology featuring an elongated rachis and tenacious glumes. Speltoids
are considered undesirable spike aberrants in wheat breeding leading to increased heterogeneity within a cultivar candidate.
As a consequence, the presence of speltoids may result in rejection of a cultivar candidate during official field trials or
denial of cultivar certification during seed multiplication. A reliable method is, thus, required to assess the occurrence
of speltoids, early on in a wheat breeding program. The domestication gene Q located on the long arm of wheat chromosome 5A is known to suppress the speltoid phenotype in wheat. Here, a quantitative
pyrosequencing assay was developed to distinguish between normal wheat plants, which possess two copies of the Q allele, and aberrants, which are either aneuploids lacking the correct number of chromosome 5A copies or plants which carry
the primitive q allele. An accurate and reproducible determination of the Q gene copy number was achieved for different wheat genotypes based on homoeologous sequence quantification with two primer
combinations at the Q locus. Single plants with one to four copies of the Q allele could be detected by quantitative pyrosequencing which corresponded to the occurrence of speltoid (1 Q allele), normal (2 Q alleles), and compact (more than 2 Q alleles) spikes. Q and q specific alleles could be differentiated at SNP position 2299 of the Q gene. This SNP is assumed to be related to the emergence of free-threshing wheat forms. To our knowledge this is the first
report for detection of aneuploids and differentiation of Q alleles in bread wheat using pyrosequencing technology. In future, quantitative pyrosequencing assay can be applied in wheat
breeding programs to carry out marker-assisted selection against the presence of speltoid spike aberrants. 相似文献
25.
Elevated levels of nitrate-nitrogen (NO3-N) in the surficial aquifer above the drinking water quality standard, i.e. maximum contaminant limit (MCL; 10 mg L−1), have been reported in some part of central Florida citrus production regions. Soils in this region are very sandy (sand content >95%), hence are vulnerable to leaching of soluble nutrients and chemicals below the rooting depth of the trees. The objective of this research was to develop N and irrigation best management practices for citrus in sandy soils to maintain optimal crop yield and quality, and to minimize potential leaching of nitrate below the root zone. Six years of field experiment was conducted in a high productive (mean fruit yield > 80 Mg ha−1yr−1) >20-year-old ‘Hamlin’ orange trees [Citrus sinensis (L.) Osbeck] on ‘Cleopatra mandarin’ (Citrus reticulata Blanco) rootstock grown on a well drained Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) in Highland county, FL. Nitrogen rates ranged from 112 to 280 kg ha−1 yr−1 applied as fertigation (FRT), water soluble granular (WSG), 50:50 mix of FRT and WSG, and controlled-release fertilizer (CRF). Tensiometers were used to monitor the soil water content as a basis to schedule optimal irrigation. Fruit yield response over the entire range of N rates was greater for the FRT and WSG sources as compared to that for the WSG + FRT or CRF sources. Using the regression analysis of the fruit yield in relation to N rate, the optimum N rate appeared to be at 260 kg ha−1 yr−1. Based on fruit production response in this study, the N requirement for production of 1 Mg of fruit varied from 2.2 to 2.6 kg across four N sources. This study demonstrated an increased N uptake efficiency, as a result of best management of N and irrigation applications. The optimal N and K concentration in the 4–6-month-old spring flush leaves were 26–30, and 15–18 g kg−1, respectively. However, fruit yield response showed no significant relationship with concentrations of P in the 4–6-month-old spring flush leaves over a range of 0.8–2.4 g kg−1. The results of fate and transport of N in soil and in soil solution with application of different rates and sources of N, and components of citrus tree N budget, are reported in a companion paper. 相似文献
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J. Schumann S. Basiouni T. Gück H. Fuhrmann 《Journal of animal physiology and animal nutrition》2014,98(6):1013-1020
Canine atopic dermatitis (CAD) is an inflammatory skin disorder that is characterized by pruritus and associated cutaneous changes. Treatment interventions include allergen avoidance, allergen‐specific immunotherapy as well as a symptomatic therapy using glucocorticoids and antihistamines. In addition, a dietary intervention using polyunsaturated fatty acids (PUFA) has been shown to alleviate symptoms in some dogs. Although the beneficial effects of PUFA in the treatment of CAD have been known for several years, their mode of action remains unclear. This review discusses the evidential basis of the therapeutic use of dietary PUFA in the treatment of CAD. Particular emphasis will be placed on the role of cutaneous mast cells. In addition, recent evidence from in vitro studies on the regulation of mast cell exocytosis will be used to build a mechanistic model of the active principle of PUFA. It is proposed that dietary PUFA are integrated into mast cell membranes resulting in a reorganization of membrane microdomains. This may then be accompanied by functional changes of membrane‐associated proteins such as the phospholipases D (PLD), enzymes having an important impact on mast cell exocytosis processes. 相似文献
28.
M.M. Swindle R.E. Schumann W.S. Johnson B. Knick A.C. Smith B.A. Carabello M. Zile C.L. Case P.C. Gillette 《Veterinary anaesthesia and analgesia》1991,18(Z1):273-276
Abstract: Protocols for utilizing intravenous infusions of sufentanil were developed for experimental cardiac surgery in swine and dogs. After initial experiences with fentanyl, sufentanil was selected for these procedures due to its increased potency and shorter half life thus requiring a smaller volume for infusion and more control. In dogs with experimental mitral valve regurgitation, an initial bolus of sufentanil 3 γg/kg IV was followed by a continuous IV infusion at a rate of 9–13 γg/kg/hr. Swine used in experiments involving cardiac conduction system ablation received ketamine 33 mg/kg IM and acepromazine 1.1 mg/kg IM as a preanesthetic combination. Following the preanesthetic, an initial infusion of sufentanil 15 γg/kg/hr was started and a loading dose of sufentanil 7 γg/kg IV was administered as a bolus for induction. They were then maintained by a continuous IV infusion at a rate of 15–30 γg/kg/hr. Dogs but not pigs required periodic supplementation of anaesthesia with isoflurane and/or nitrous oxide during portions of the experimental protocol. No anaesthetic related deaths have occurred in either species using these anaesthetic protocols for cardiac procedures. 相似文献
29.
Daniela H. Haarmeyer Katharina Schumann Markus Bernhardt-Römermann Rüdiger Wittig Adjima Thiombiano Karen Hahn 《Agroforestry Systems》2013,87(6):1363-1375
Non-timber forest products (NTFPs) are of high socio-economic value for rural people in West Africa. Main factors determining the status of the populations of socio-economically important tree species providing those NTFPs are human activities. This study assesses the impact of human population density, land use, and NTFP-harvesting (pruning and debarking) on population structure and fruit production of the socio-economically important tree Lannea microcarpa that is normally conserved by farmers on fields. We compared L. microcarpa stands of protected sites with those of their surrounding communal sites in two differently populated areas in Burkina Faso. Our results reveal an opposed land use impact on the population structure of L. microcarpa in the two areas. In the highly populated area, the species population was more stable in the protected site than in the communal site, while the opposite was observed for the less populated area. Trees of the communal sites bore more fruits than trees of the protected sites. Debarking and pruning had a negative impact on fruit production of the species. We conclude that low intensity of human impact is beneficial for the species and that indirect human impact facilitates fruit production of L. microcarpa. In contrast, in the densely populated area, human impact has reached an intensity that negatively affects the populations of L. microcarpa. While the extent of protecting L. microcarpa on fields still seems to be enough to guarantee the persistence of this important species in the less populated area, it is no longer sufficient in the densely populated area. 相似文献
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