Latent heat flux over Cabernet Sauvignon vineyard using the Shuttleworth and Wallace model     

S. Ortega-Farias  M. Carrasco  A. Olioso  C. Acevedo  C. Poblete 《Irrigation Science》2007,25(2):161-170

The Shuttleworth and Wallace model (SW) was evaluated to estimate latent heat flux above a drip-irrigated Cabernet Sauvignon vineyard, located in the Pencahue Valley, Region del Maule, Chile (35°22′ LS; 71°47′ LW; 150 m above sea level). The performance of the WS model (LE_ws) was evaluated against the eddy-covariance method (LE_ed) on a 30 min time interval. Results indicate that the root mean square error (RMSE) and mean absolute error (MAE) were 29 W m⁻² and 22 W m⁻², respectively. For the vine evapotranspiration (ETv), RMSE was 0.42 mm day⁻¹ and MAE was 0.36 mm day⁻¹. The largest disagreements between LE_ed and LE_ws were observed under dry atmospheric conditions. Also, the sensitivity analysis indicates that predicted ETv by the SW model was sensitive to errors of ±30% in leaf area index and mean stomatal resistance, but it was not affected by errors in the estimation of aerodynamic resistances.  相似文献   

A lesion-mimic mutant of wheat with enhanced resistance to leaf rust   总被引：2，自引：0，他引：2  

C. A. Kamlofski  E. Antonelli  C. Bender  M. Jaskelioff†  C. H. Danna‡  R. Ugalde  A. Acevedo 《Plant pathology》2007,56(1):46-54

A lesion-mimic mutant was obtained from a mutagenic treatment performed with ethyl methanesulfonate on the Argentine bread wheat ( Triticum aestivum ) cultivar Sinvalocho M.A. The HLP (hypersensitive-like phenotype) mutant exhibited tiny, discrete, white lesions in the absence of any pathogen, resembling the typical hypersensitive response (HR). The lesions only became evident once the fifth or sixth leaf emerged, and spread at random along the leaf blades and leaf sheaths of the developing plant, including tissues of the spike. Because the lesion-mimic mutant showed no lesions at the seedling stage, the phenotypes of both the mutant and its mother line were identical at this point. Histochemical studies showed that spontaneous hypersensitive-like lesions in the HLP mutant corresponded to cell death. In leaf-rust ( Puccinia triticina ) infection experiments performed at seedling and adult-plant stages, adult HLP plants showed enhanced resistance to leaf-rust attack compared with plants of Sinvalocho M.A. of comparable developmental stage, suggesting that the HLP mutation may confer increased resistance to the fungus. Because enhanced resistance coincided with the presence of spontaneous HR lesions, activation of HLP plant defence responses appeared to be tightly linked to this phenomenon. Final plant height and yield components in the lesion-mimic mutant did not differ from those of the mother line, indicating that the HLP mutation caused no detrimental pleiotropic effects that significantly affected agronomic performance. These data support the direct use of mutations in disease-resistance breeding.  相似文献   

Nitrogen loading of Eucalyptus globulus seedlings: nutritional dynamics and influence on morphology and root growth potential     

Acevedo  Manuel  Rubilar  Rafael  Dumroese  R. Kasten  Ovalle  Juan F.  Sandoval  Simón  Chassin-Trubert  Rodrigo 《New Forests》2021,52(1):31-46

New Forests - Achieving successful outplanting of trees on increasingly harsher sites is a global concern. In Chile, for example, new Eucalyptus globulus plantations are being targeted to poorer,...  相似文献   

Evaluation of β-(1 → 3, 1 → 6)-glucans and High-M alginate used as immunostimulatory dietary supplement during first feeding and weaning of Atlantic cod (Gadus morhua L.)     

Jorunn Skjermo  Trond R. Størseth  Karina Hansen  Gunvor Øie 《Aquaculture (Amsterdam, Netherlands)》2006,261(3):1088-1101

Stimulation of the non-specific defence enhances the disease resistance and growth, and has good potentials as a measure for increased microbial control in juvenile production of marine fish and shellfish. So far, the most commonly used immunostimulants are β-(1 → 3, 1 → 6)-glucans, and in this study the stimulatory potential of a β-(1 → 3, 1 → 6)-glucan of marine origin, the storage polysaccharide from the marine diatom Chaetoceros mülleri, was examined. The glucan (chrysolaminaran) was extracted from cultures of C. mülleri, and used as a dietary supplement in two first feeding experiments with larvae of Atlantic cod Gadus morhua L. In one experiment the microalgal glucan was compared to the commercial yeast-glucan product MacroGard®, and in the other to an alginate with a high content of mannuronic acid (High-M alginate) isolated from Durvillaea antarctica. The stimulants were given via rotifers, and weaning to formulated feed was initiated at day 17 or 18 after hatching. The survival ± SEM at day 27 after hatching was 24.5 ± 2.0%, 14.8 ± 4.5% and 13.1 ± 1.4% for the groups fed C. mülleri-glucan, yeast glucan and for the control, respectively, in the first experiment. The group fed C. mülleri-glucan group had higher survival compared to the control (P < 0.05) group, whereas the yeast glucan had no positive effect on the survival (p > 0.05). The dry weights of the groups at day 27 were low, with 203.2 ± 52.2, 165.2 ± 43.4 and 198.5 ± 58.1 μg per larva for the C. mülleri-glucan, yeast glucan and control groups, respectively. In the second experiment the survival in the period of feeding formulated feed (days 18-30) were 44.6 ± 4.3%, 44.7 ± 1.3%, and 33.8 ± 4.1% survival for the C. mülleri-glucan, High-M alginate and control group, respectively. The cod larvae fed C. mülleri-glucan reached an average weight of 531.6 ± 17.2 μg at day 30, which was significantly higher (p < 0.05) than the control group that had an average of 473.6 ± 3.5 μg. The larvae fed High-M alginate had an average weight of 470.3 ± 31.6 μg per larva at day 30, and not significantly different from the control (p > 0.05). The early weaning to formulated diet had detrimental effect on the growth of the larvae. In both experiments the C. mülleri-glucan group was the only group showing a positive growth rate in the period of weaning to dry feed. The microbial conditions in larval gut and water were monitored with respect to total colony forming units on Marine agar, and Vibrio- and Pseudomonas-like species on selective agars (TCBS and marine Pseudomonas Agar with CFC-supplement). The larvae were rapidly colonised after hatching, but no or weak effects of the stimulants were observed on the colonisation rates or the composition. The total CFU varied from 10¹ to 10² CFU per μg larva after initiation of the first feeding. The percentages of Pseudomonas-like bacteria increased throughout the period, whereas the levels of Vibrio-like bacteria were low and stable. The chrysolaminaran from the diatom C. mülleri was shown to be a promising candidate for use as an immunostimulatory feed additive, and which should be further explored.  相似文献   

Genetic differentiation among Atlantic island populations of the brown spiny lobster Panulirus echinatus (Decapoda: Palinuridae)     

Juliana Gaeta  Ivn Acevedo  Violeta Lpez‐Mrquez  Rui Freitas  Raúl Cruz  Rodrigo Maggioni  Rogelio Herrera  Annie Machordom 《水产资源保护:海洋与淡水生态系统》2020,30(5):868-881

1. Declines in Panulirus echinatus Smith, 1869 populations along their wide distribution in the Atlantic Ocean have spurred efforts to improve their fisheries management and conservation. In this study, the genetic structure of these populations is reported for the first time.
2. In a survey of 18 species‐specific polymorphic microsatellite markers, 152 individuals were genotyped from five Atlantic oceanic islands, covering most of the insular distribution range of the species. The analyses revealed that P. echinatus is genetically partitioned into two stocks in the Atlantic Ocean. A highly significant genetic structure was observed between north‐east and south‐west Atlantic populations based on fixation index, discriminant analysis of principal components, and structure and barrier analysis.
3. We suggest that the Equatorial Circulation System represents a biophysical barrier that effectively limits migration among Atlantic subtropical gyre systems, as has been described for other species. Other physical and ecological barriers, such as the Mid‐Atlantic Ridge itself, the distance between the eastern and western sides of the Atlantic (Mid‐Atlantic Barrier) and water mass differences, as well as other biological aspects, may also influence larval dispersal and modulate the insular distribution of this species.
4. The results show the existence of two distinct genetic stocks of P. echinatus and have implications for fisheries management in the Atlantic Ocean, including their independent management according to their individual status. The Cabo Verde and the Canarian populations (north‐east Atlantic) showed the lowest level of genetic variability in comparison with the south‐western populations. A combination of factors that have occurred or are occurring in the Canary Islands, such as overfishing and volcanic eruptions, is likely to explain the reduced abundance of this lobster species in the area.

  相似文献   

Tracking Anthropogenic Inputs in Barigui River, Brazil Using Biomarkers     

Sandro Froehner  Daniele Botelho Souza  Karina Scurupa Machado  Edson Cordova da Rosa 《Water, air, and soil pollution》2010,210(1-4):33-41

The Barigüi River watershed is located in the metropolitan region of Curitiba, Southern Brazil, passing through several neighboring counties. In recent years, due to growth and disorderly occupation along the river, in addition to lack of sanitation, the Barigüi River suffered a very large inflow of untreated domestic wastewater. Current programs to monitor the watershed use traditional physical–chemical parameters. Here, the presence of some molecular tracers found in domestic effluents was investigated, such as caffeine and coprostanol at some selected sites in Barigüi River. Caffeine is highly soluble in water and its presence in water bodies is due to the disposal of untreated sewage. Caffeine is eliminated in the urine (approximately 0.5% to 10% of the consumption). The samples were collected in three campaigns, two in dry weather and another during a week in the rainy season. The results showed that caffeine concentration ranged between zero and 753.5 μg g^?1. Higher values were found on rainy days. Caffeine showed a positive correlation between BOD and nitrate; it also showed a positive correlation with coprostanol, a fecal biomarker. Finally, caffeine has been shown to be a good parameter to determine the contamination by domestic wastewater.  相似文献   

Evaluation of proline analysis and chlorophyll fluorescence quenching measurements as drought tolerance indicators in durum wheat (Triticum turgidum L. var. durum)     

T. Ali Dib  Ph. Monneveux  E. Acevedo  M. M. Nachit 《Euphytica》1994,79(1-2):65-73

Summary The possibility of using proline accumulation and fluorescence inhibition as predictive tests for drought tolerance in durum wheat has been investigated. The drought susceptibility of 25 genotypes was evaluated by comparing yields and yield components in irrigated and non irrigated conditions in the field. A drought susceptibility index (DSI) was calculated based on yields from irrigated and dry treatments and compared with the results obtained using the two physiological criteria. Proline accumulation and chlorophyll fluorescence inhibition were found to be significantly and negatively correlated with DSI of grain yield, biological yield, and thousand kernel weight, and tiller index. The use of both criteria for breeding durum wheat in Mediterranean dryland is discussed.  相似文献   

Occurrence and distribution of organochlorine pesticides (OCPs) in tomato (Lycopersicon esculentum) crops from organic production     

Gonzalez M  Miglioranza KS  Aizpún de Moreno JE  Moreno VJ 《Journal of agricultural and food chemistry》2003,51(5):1353-1359

Organochlorine pesticides (OCPs) were quantified by GC-ECD in tomato (Lycopersicon esculentum) during a vegetation period. Plants were harvested at 15, 60, and 151 days after seed germination. Leaves, stem, roots, and fruit (peel and flesh) were analyzed separately. The results showed that tomato plants were able to accumulate OCPs from soils, and a trend to reach the equilibrium among tissues at mature stages was also observed. Endosulfans comprised the main OCP group, probably due to its spray during summer months in the surrounding areas. Banned pesticides such as DDTs, heptachlor, and dieldrin were found. OCPs levels in the fruit were below the maximum residues limits (MRL) considered by the Codex Alimentarius. DDE/DDT and alpha-/gamma-HCH ratios of <1 would indicate recent inputs of DDT and lindane in the environment. The occurrence of OCPs in the study farm, where agrochemicals have never been used, is a result of atmospheric deposition of those pesticides.  相似文献   

Implantation of exogenous enzymatic activity in isolated alveolar macrophages     

J Theodore  J C Acevedo  E D Robin 《Science (New York, N.Y.)》1972,178(67):1302-1304

Alveolar macrophages acquired the capacity to oxidize uric acid after exposure to uricase. Presumably this resulted from intracellular incorporation of the enzyme by endocytosis. This approach may provide a general method for (i) testing regulatory biochemical mechanisms, (ii) therapeutic replacement of deficient regulatory macromolecules, and (iii) studying environmental factors that produce genetic alterations.  相似文献   

Protecting invaders for profit     

Lambertucci SA  Speziale KL 《Science (New York, N.Y.)》2011,332(6025):35

  相似文献