Recent progress in the field of N-acylalanines as systemic fungicides     

Franco Gozzo  Luigi Garlaschelli  Pier M. Boschi  Angela Zagni  Jean C. Overeem  Lambertus de Vries 《Pest management science》1985,16(3):277-286

The influence of structural variations in compounds of the N-acylalanine type, on their fungicidal activity towards Peronosporales, was examined. Within a series of methyl N-(acyl)-N-(2,6-xylyl)alaninates ( I ), a quantitative structure-activity relationship was given for the curative action against Plasmopara viticola, through a Hansch-type equation. A deviation from this equation is discussed with reference to benalaxyl ( I ; acyl=phenylacetyl). Syntheses and qualitative indications of activity are reported for structural changes in the xylyl and in the alanine moieties. Progress in the latter approach is briefly outlined.  相似文献   

Presence of Grapevine leafroll-associated virus 3 in primary salivary glands of the mealybug vector Planococcus citri suggests a circulative transmission mechanism     

Miguel Cid  Sonia Pereira  Cristina Cabaleiro  Franco Faoro  Antonio Segura 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(1):23-30

Grapevine leafroll-associated virus 3 (GLRaV-3) is a mealybug-transmissible ampelovirus. Though the transmission mechanism has been described as semipersistent on the basis of temporal parameters, definitive proof of this mechanism has never been provided. In the present study, we carried out preliminary assays to establish the location of the virus in its vector, Planococcus citri. After dissecting the insects, GLRaV-3 was detected by means of IC-RT-PCR in the salivary glands, intestine and Malpighian tubes, but not in the sucking apparatus. Immunogold labelling of the capsid protein revealed the presence of the virus in some cells of the primary salivary glands, but not in the alimentary channel of the stylet, or in the accessory salivary glands. The strong labelling of the electron-dense secretion vesicles in some cells of the primary salivary glands, together with the non-detection of the virus in the sucking apparatus suggests that the transmission mechanism may be different from that previously described. We propose a circulative transmission mechanism based on a specific transportation route for the viral particles from the midgut or hindgut to the salivary glands. As the transmission mechanism is generally a common feature of a viral genus, the existence of a circulative transmission mechanism for other mealybug-transmitted ampeloviruses is expected. Organ by organ analysis of GLRaV-1, another ampelovirus not transmissible by P. citri, showed the absence of the virus in the salivary glands, thus providing further, though indirect, evidence in favour of circulative transmission for this virus genus.  相似文献   

Chemical Reduction of Hexavalent Chromium and Its Immobilisation Under Batch Conditions Using a Slurry Reactor     

Franco  Débora V.  Da Silva  Leonardo M.  Jardim  Wilson F. 《Water, air, and soil pollution》2009,200(1-4):305-321

Water, Air, & Soil Pollution - Risks posed by antifouling agents (irgarol 1051, diuron and dichlofluanid) to the aquatic environment of the Gulf of Napoli have been estimated. Seawater samples...  相似文献   

On-farm evaluation of a low-input rice production system in Panama     

Marie-Soleil Turmel  Juan Espinosa  Le��n Franco  Candelario P��rez  Horacio Hern��ndez  Eric Gonz��lez  Guillermo Fern��ndez  Carlos Rojas  Daniel S��nchez  Nicol��s Fern��ndez  Manuel Barrios  Joann K. Whalen  Benjamin L. Turner 《Paddy and Water Environment》2011,9(1):155-161

On-farm trials were conducted to evaluate the potential of the System of Rice Intensification (SRI), a low-input crop management system, to increase rice yields and reduce water consumption on subsistence farms in several regions of Panama and to determine how inherent soil fertility might affect SRI yields and the yield response to SRI management in the first season of SRI management. SRI practices increased yield by 47% on average and showed potential to increase yield by over 90%, while reducing water consumption by as much as 86%. SRI yields were correlated with available soil K and the difference between SRI and the conventional system yields was positively correlated with extractable Ca, Mg and Mn. The results of this study indicate that SRI is a promising rice production system for smallholder farmers in rural Panama farming under Panamanian soil conditions.  相似文献   

Complementary therapies for treating alcoholism First Annual meeting by Complementary Medicine Research Group of the Italian Society for Alcohol Studies-May 5, 2006, Florence, Italy     

Abenavoli L  Bardazzi G  Cracolici F  Quaranta C  Santini G  Graziosi S  Polero L  Leggio L  Addolorato G 《Fitoterapia》2008,79(2):142-147

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New phenolic esters from the resinous exudate of Haplopappus taeda     

Faini F  Labbé C  Torres R  Rodilla JM  Silva L  Delle Monache F 《Fitoterapia》2007,78(7-8):611-613

Two new phenolic esters 9-trans-p-coumaroyloxy-alpha-terpineol (1) and 7-trans-p-coumaroyloxy-taedol (2), both endowed with free radical scavenger activity and cleroda-3,13 (E)-dien-15,18-diol (3) for which a cis stereochemistry at the decalin junction was found, were isolated from the resinous exudate from Haplopappus taeda upper parts.  相似文献   

Identification of four novel members of Kunitz-like α-amylase inhibitors family from Delonix regia with activity toward Coleopteran insects     

Debora T. Alves  Ilka M. Vasconcelos  Jos T.A. Oliveira  Luciana R. Farias  Simoni C. Dias  Marileusa D. Chiarello  Simone Maria-Neto  Octvio L. Franco 《Pesticide biochemistry and physiology》2009,95(3):166-172

Crop improvement generally focuses on yield, seed quality and nutritional characteristics, rather than resistance to biotic and abiotic stresses. A clear consequence of this approach is the absence of natural anti-feedant toxins in some improved seed materials, allowing predation of commercial crops by insect herbivores. Cowpea (Vigna unguiculata), commonly cultivated by small farmers, is particularly affected by insect-pests that reproduce and develop inside stored seeds. One alternative to conventional pesticides for pest control is the use of biotechnological tools, such as the digestive enzyme inhibitors, that could be introduced in transgenic crops to enhance resistance. In this study, it was verified that the in vivo bioassays using artificial seeds containing 0.5%, 1.0% and 1.5% (w/w) of Delonix regia rich fraction, containing α-amylase inhibitors with effectiveness toward insect α-amylases and other sources, caused remarkable reduction in development and increased mortality of Callosobruchus maculatus cowpea weevil and to cotton boll weevil Anthonomus grandis. Therefore, attempts were made to isolated those inhibitors by SP-Sepharose ion exchange chromatography followed by high performance liquid chromatography on a Vydac C18-TP analytical column. Four inhibitor peaks were obtained with molecular masses of 6.0, 20 and 24 kDa. Their N-termini showed high sequence similarities with Kunitz-like inhibitor family members. These results provide evidence that D. regia synthesizes a multiple family of Kunitz-like α-amylase inhibitors, with different molecular masses and a wide biotechnological potential to control insect-pests.  相似文献   

Identification of 19-epi-okadaic Acid,a New Diarrhetic Shellfish Poisoning Toxin,by Liquid Chromatography with Mass Spectrometry Detection          下载免费PDF全文

Beatriz Paz  Antonio H. Daranas  Patricia G. Cruz  José M. Franco  Manuel Norte  José J. Fernández 《Marine drugs》2008,6(3):489-495

Okadaic acid (1) (OA) and its congeners are mainly responsible for diarrhetic shellfish poisoning (DSP) syndrome. The presence of several OA derivatives have already been confirmed in Prorocentrum and Dinophysis spp. In this paper, we report on the detection and identification of a new DSP toxin, the OA isomer 19-epi-okadaic acid (2) (19-epi-OA), isolated from cultures of Prorocentrum belizeanum, by determining its retention time (RT) and fragmentation pattern using liquid chromatography coupled with mass spectrometry (LC–MS/MS).  相似文献   

Soils in the semi-arid area of the El Melah Lagoon (NE Tunisia) — Variability associated with a closing evolution     

M.I. Prudêncio  M.I. Dias  F. Ruiz  J.C. Waerenborgh  J. Duplay  R. Marques  D. Franco  R. Ben Ahmed  M.A. Gouveia  M. Abad 《CATENA》2010

Soils of the semi-arid area of the El Melah coastal lagoon (NE Tunisia), with a closing evolution dynamic, were studied aiming: (1) the chemical and mineralogical characterization of surface and subsurface layers of soil profiles from locations previously submerged and of soils developed on dunes; (2) to evaluate the dependence on the environment conditions of the geochemical patterns of the soils; and (3) to determine chemical and mineralogical variations with the emersion of the sediments resulting from the decrease in the extent of the area permanently covered by water in the lagoon. The compositional results obtained showed significant differences depending on the environment (littoral plain, old dunes and sandy spit), but soils of the different environmental zones studied do not appear to be significantly polluted as far as trace elements are concerned. Among the elements studied, high element/Sc ratios and variations were found for As, Sb and Zn. Antimony is more concentrated in coarser samples suggesting its adsorption in Fe or Mn oxides coating quartz grain surfaces. Arsenic and zinc may be incorporated into the carbonates structure, as well as adsorbed on, or coprecipitated with, iron oxides. Zinc may also be significantly incorporated in clay minerals. Iron was found to be more oxidized in the cultivated soil from the old dune strand; and more reduced in the sandy spit where ankerite occurs suggesting the reduction of Fe³⁺ in oxide/hydroxides by microorganisms and incorporation of Fe²⁺ in carbonates. REE patterns, particularly the HREE/LREE are correlated with carbonates, indicating preferential incorporation of the HREE in carbonates, and of the LREE in clay minerals/iron oxides. High Ga contents were found in soils and sediments rich in clay minerals/Al, suggesting its incorporation in clay minerals structure. Therefore, Ga may be used as an indicator of the clay minerals proportion in sediments and soils. Carbonates, sulphates, besides Fe and/or Mn oxides and clay minerals, appear to play an important role on the trace elements distribution.  相似文献   

Assessment of vineyard water status variability by thermal and multispectral imagery using an unmanned aerial vehicle (UAV)   总被引：3，自引：0，他引：3  

Javier Baluja  Maria P. Diago  Pedro Balda  Roberto Zorer  Franco Meggio  Fermin Morales  Javier Tardaguila 《Irrigation Science》2012,30(6):511-522

The goal of this study was to assess the water status variability of a commercial rain-fed Tempranillo vineyard (Vitis vinifera L.) by thermal and multispectral imagery using an unmanned aerial vehicle (UAV). The relationships between aerial temperatures or indices derived from the imagery and leaf stomatal conductance (g _s) and stem water potential (Ψ_stem) were determined. Aerial temperature was significantly correlated with g _s (R ²?=?0.68, p?<?0.01) and Ψ_stem (R ²?=?0.50, p?<?0.05). Furthermore, the thermal indices derived from aerial imagery were also strongly correlated with Ψ_stem and g _s. Moreover, different spectral indices were related to vineyard water status, although NDVI (normalized difference vegetation index) and TCARI/OSAVI (ratio between transformed chlorophyll absorption in reflectance and optimized soil-adjusted vegetation index) showed the highest coefficient of determination with Ψ_stem (R ²?=?0.68, p?<?0.05) and g _s (R ²?=?0.84, p?<?0.05), respectively. While the relationship with thermal imagery and water status parameters could be considered as a short-term response, NDVI and TCARI/OSAVI indices were probably reflecting the result of cumulative water deficits, hence a long-term response. In conclusion, thermal and multispectral imagery using an UAV allowed assessing and mapping spatial variability of water status within the vineyard.  相似文献