Nitrogen fertilization of warm‐season turfgrasses irrigated from varying irrigation systems: 2. Carbohydrate and protein content          下载免费PDF全文

M. Serena  M. Schiavon  R. Sallenave  B. Leinauer 《Journal of Agronomy and Crop Science》2018,204(3):265-273

A 3‐year study was conducted at New Mexico State University in Las Cruces, NM, to investigate whether different fertilization treatments affect the carbohydrate and protein content in two warm‐season grasses grown using water conservation strategies such as non‐potable saline irrigation water and a subsurface irrigation system. “Princess 77” bermudagrass (Cynodon dactylon L.) and “Sea Spray” seashore paspalum (Paspalum vaginatum O. Swartz) were irrigated with either potable (electrical conductivity [EC] = 0.6 dS m^?1) or saline (EC = 3.1 dS m^?1) water from either an overhead or a subsurface drip irrigation system. Four different fertilizers were used in this study: liquid slow release, granular slow release, granular urea and urea liquid, at two rates: 10 and 20 g N m^?2 yr^?1 for “Sea Spray” and 20 and 30 g N m^?2 yr^?1 for “Princess 77.” Carbohydrate (sucrose, starch, total soluble carbohydrates and total non‐structural carbohydrates) and protein content of the grasses were measured, and their effect on spring green‐up was determined. The total carbohydrate content within the stolons and rhizomes was found to be closely associated with speed of spring green‐up, resulting in R² values ranging from 0.36 to 0.76. The relationship between green‐up and carbohydrate content was similar for both grasses. Fertilizer treatment did not affect carbohydrate content in either grass under either irrigation system. Further analysis revealed that carbohydrate content in February was the best determinant for spring green‐up. Other sampling months also showed a significant correlation with spring green‐up, but with lower R² values.  相似文献   

From fish‐processing waste to feed additives for crayfish     

Yamila Eliana Rodriguez  Hernn Javier Sacristn  María Victoria Laitano  Laura Susana Lpez‐Greco  Analía V. Fernndez‐Gimenez 《Journal of the World Aquaculture Society》2019,50(5):954-968

This research studied the in vitro compatibility of Cherax quadricarinatus digestive proteases and crude enzyme extracts recovered from fish‐processing waste to evaluate their potential use as feed additives to increase digestion efficiency in decapod crustaceans. The sources of exogenous enzymes were: Pleoticus muelleri (Pm), Artemesia longinaris (Al), and Illex argentinus (Ia). The midgut glands of early (7.2 ± 0.34 g) and advanced juveniles (13.8 ± 1.49 g) of C. quadricarinatus were used for all the assays. The compatibility and synergy between crayfish and exogenous enzymes were evaluated through sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) electrophoresis and the hydrolysis of azocasein and four different meals. SDS–PAGE gels demonstrated that crayfish bands remained active when their enzymes were combined with the enzymes from Pm and Ia. An apparent enzymatic synergism was found when Pm and crayfish proteases were incubated together at pH 6 and 8 with azocasein (p ? 0.05). The ability to hydrolyze the different feed ingredients varied among the enzyme combinations assayed. Our findings suggest that fish waste has potential as a source of proteases, adding value to these processing residues and promoting a zero‐waste industry. Enzymes obtained from Pm and Ia are suitable to be used as food additives for crayfish. The results should be validated through feeding trials.  相似文献   

Antimicrobial Photodynamic Therapy: Study of Bacterial Recovery Viability and Potential Development of Resistance after Treatment     

Anabela Tavares  Carla M. B. Carvalho  Maria A. Faustino  Maria G. P. M. S. Neves  Jo?o P. C. Tomé  Augusto C. Tomé  José A. S. Cavaleiro  ?ngela Cunha  Newton C. M. Gomes  Eliana Alves  Adelaide Almeida 《Marine drugs》2010,8(1):91-105

Antimicrobial photodynamic therapy (aPDT) has emerged in the clinical field as a potential alternative to antibiotics to treat microbial infections. No cases of microbial viability recovery or any resistance mechanisms against it are yet known. 5,10,15-tris(1-Methylpyridinium-4-yl)-20-(pentafluorophenyl)-porphyrin triiodide (Tri-Py⁺-Me-PF) was used as photosensitizer. Vibrio fischeri and recombinant Escherichia coli were the studied bacteria. To determine the bacterial recovery after treatment, Tri-Py⁺-Me-PF (5.0 μM) was added to bacterial suspensions and the samples were irradiated with white light (40 W m⁻²) for 270 minutes. Then, the samples were protected from light, aliquots collected at different intervals and the bioluminescence measured. To assess the development of resistance after treatment, bacterial suspensions were exposed to white light (25 minutes), in presence of 5.0 μM of Tri-Py⁺-Me-PF (99.99% of inactivation) and plated. After the first irradiation period, surviving colonies were collected from the plate and resuspended in PBS. Then, an identical protocol was used and repeated ten times for each bacterium. The results suggest that aPDT using Tri-Py⁺-Me-PF represents a promising approach to efficiently destroy bacteria since after a single treatment these microorganisms do not recover their viability and after ten generations of partially photosensitized cells neither of the bacteria develop resistance to the photodynamic process.  相似文献   

Evaluation of Physicochemical and Sensory Properties of Sausages Made with Washed and Unwashed Mince from Nile Tilapia By-products     

Paulo Roberto Campagnoli de Oliveira Filho  Elisabete Maria Macedo Viegas  Eliana Setsuko Kamimura  Marco Antonio Trindade 《Journal Of Aquatic Food Product Technology》2013,22(3):222-237

This study evaluates the effects of inclusion level (60 to 100%) and washing cycles (0 to 2) of minced fish from Nile tilapia fillet by-products on proximate composition, mineral contents, color, hardness, and sensory acceptance of sausages. A complete 2² factorial experimental design was used. Regression models for protein, fat, moisture, minerals, color, and hardness were developed. The optimum combinations for the independent variables are sausages made with 100% non-washed minced fish, which represents a better use of by-products without generating washing residues, leading to less expensive sausage with higher nutritional value.  相似文献   

<Emphasis Type="Italic">Clavibacter michiganensis</Emphasis> subsp. <Emphasis Type="Italic">michiganens</Emphasis>is strains virulence and genetic diversity. a first study in Argentina     

Eliana Wassermann  Marcela Susana Montecchia  Olga Susana Correa  Vega Damián  Ana María Romero 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(1):35-44

Tomato leaves showing severe leaf spot symptoms have been observed and sampled in the central west and southwest Taiwan during 2015 and 2016. The symptoms were similar to those of bacterial leaf spot/late blight diseases, but only Stemphylium-like fungi were consistently isolated from the diseased tomato. Upon spray inoculation of tomato, Stemphylium-like isolates caused leaf spot symptoms identical to those of naturally infected plants, and the pathogenic isolates were successfully re-isolated from inoculated leaves. The tomato-pathogenic isolates were identified as S. lycopersici based on morphological characterization and molecular identification. S. lycopersici has been previously reported to cause gray leaf spot of tomato in the temperate regions, but the majority of S. lycopersici-caused lesions were black/dark brown rather than gray in our surveillance. Accordingly, it is suggested that S. lycopersici-caused disease of tomato is named Stemphylium leaf spot of tomato more appropriately than tomato gray leaf spot. Moreover, S. lycopersici-caused leaf spot disease on tomato has been distributed in major tomato production regions in Taiwan. The information provided by our study will be important for future breeding of tomato cultivars, especially for tomato producers in Taiwan.  相似文献   

Post-catastrophe Analysis of the Fundão Tailings Dam Failure in the Doce River System,Southeast Brazil: Potentially Toxic Elements in Affected Soils     

Marcelo Braga Bueno Guerra  Brian T. Teaney  Brianna J. Mount  Daniel J. Asunskis  Brennan T. Jordan  Ryan J. Barker  Eliana E. Santos  Carlos Ernesto G. R. Schaefer 《Water, air, and soil pollution》2017,228(7):252

On November 5, 2015, after the collapse of the Fundão tailings dam, a massive amount of iron mine waste was released into the Doce River system in southeast Brazil. The aim of our study was to determine the mass fractions of potentially toxic elements in soil affected by the deposition of material by the waste wave. A preliminary screening was performed with portable X-ray fluorescence spectrometry (PXRF) and principal component analysis (PCA). The EPA 3050B method was further applied to digest the samples for quantitative determination of As, Ba, Cr, Cu, Mn, Ni, Pb, V, and Zn by inductively coupled plasma mass spectrometry. PCA was useful to classify the mine waste samples based on the Fe signal from the PXRF spectra, in spite of the heterogeneous nature of the material discharged into the Doce River system. The anomalous levels of As (up to 164 mg kg^?1) and Mn (as high as 2410 mg kg^?1) found in some mine waste and affected soil samples are within the background ranges typically observed in the soils of the Iron Quadrangle region. The toxicity characteristic leaching procedure shows no evidence of hazards regarding As, but a high natural background level of Mn was found in the mobile fraction. This preliminary environmental assessment highlights the importance of evaluation of long-term effects on soil directly impacted, as well as on the aquatic biota of the Doce River system and adjacent coastal environment given the large affected area, which includes regions with varying background levels of toxic elements.  相似文献   

Abiotic degradation pathways of isoxaben in the environment     

Abderrahim Mamouni  Philippe Schmitt  Mohamed Mansour  Michel Schiavon 《Pest management science》1992,35(1):13-20

Photolysis of isoxaben [N-[3-(1-ethyl-1-methylpropyl)isoxazol-5-yl]-2,6-dimethoxybenzamide] in dilute aqueous solutions, adsorbed on silica gel plates, has been investigated under natural and simulated solar light conditions. Eight photoproducts were isolated and identified by spectroscopic methods. Photo-decomposition with sunlight led to the formation of three isomers, dimethoxy-benzonitrile and dimethoxybenzamide as major photoproducts. The rearrangement has been shown to proceed in two photochemical steps by way of an azirine and a non-identified photoproduct as stable intermediates. The azirine rearranges almost quantitatively to an oxazole and rearranges back to the starting isoxaben.  相似文献   

Pre- and post-embedding immunogold labeling and electron microscopy in plant host tissues of three antigenically unrelated MLOs: primula yellows,tomato big bud and bermudagrass white leaf     

R. G. Milne  Eliana Ramasso  R. Lenzi  Vera Masenga  Nonglak Sarindu  M. F. Clark 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(1):57-67

Methods are described for pre- and post-embedding immunogold labeling of mycoplasmalike organisms (MLOs) in thin sections of infected plants. Antisera against primula yellows (PY), tomato big bud (TBB) and bermudagrass white leaf (BGWL) MLOs, and a monoclonal antibody (mab) against PY were tested with the three serologically unrelated MLOs. Labeling was specific for each MLO and was localized to the outer surface of the MLOs. The antisera performed well in both pre- and post-embedding experiments; the mab reacted well in pre-embedding conditions but gave no labeling with post-embedding. Glutaraldehyde fixation reduced levels of labeling in post-embedding conditions. The results show that these techniques can be used to differentiate MLOs reliably, and extend the usefulness of electron microscopy in this area.  相似文献   

Virulence and pCM1 plasmid carriage are related to BOX-PCR fingerprint type in strains of Clavibacter michiganensis subsp. michiganensis that cause bacterial wilt and canker of tomato in Argentina     

Eliana Wassermann  Marcela S. Montecchia  Valeria S. Garaventa  Olga S. Correa  Ana M. Romero 《Plant pathology》2020,69(4):723-732

Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial wilt and canker in tomato, producing important economic losses worldwide. Its virulence has been related to several putative virulence factors present on a chromosomal pathogenicity island and on plasmids pCM1 and pCM2, in strain NCPPB382. We genotypically characterized a collection of Cmm isolates from the main greenhouse tomato-producing areas of Argentina by BOX-PCR fingerprinting and screened for the presence of genes and plasmids involved in pathogenicity by PCR. In addition, we evaluated in vitro cellulolytic activity and virulence in planta of selected strains. BOX-PCR fingerprinting clustered strains into four groups. Group II was dominant and included the most virulent strains, while Group III was the smallest and had the least virulent strains. All local strains exhibited similar cellulolytic activity. Most of the examined strains carry two plasmids of similar size to those of NCPPB382, although there were strains with one or three plasmids. By PCR amplification of repA, pCM1 was detected only in strains belonging to Group III, which includes local strains closely related to reference strain NCPPB382. All analysed pathogenicity genes were widespread among strains, and so in strains belonging to Groups I and II, celA found on pCM1 in NCPPB382 could be found in the chromosome or in plasmids other than pCM1. This study contributes to a better understanding of the diversity of Cmm genetic profiles and virulence of strains present in Argentina. Such information could be useful for the selection of strains for screening of host resistance and development of resistant tomato varieties.  相似文献   

Reducing atrazine leaching by integrating reduced herbicide use with mechanical weeding in corn (Zea mays)     

L. Heydel  M. Benoit  M. Schiavon 《European Journal of Agronomy》1999,11(3-4):217-225

Concern about the effects of pesticides on the environment and the desire to reduce purchased inputs are stimuli to reduce herbicide use. Field research was conducted for three growing seasons to compare the chemical contamination and effectiveness of three weed management practices. Weed control treatments included application of a herbicide mixture of 1.5 kg ai ha⁻¹ of atrazine plus 0.9 kg ai ha⁻¹ of pyridate, this mixture being broadcast alone or band-applied in combination with mechanical weeding, and mechanical weeding alone. The results show that it is possible to decrease the amount of atrazine residue in soil with the band-applied treatment. Such a method is very attractive because crop yields were not decreased, at least in the short run. However, we do not yet know the long-term efficiency of this method regarding groundwater quality, weed population dynamic and crop yield. Further work is therefore needed to assess the long-term impact of this weeding method.  相似文献