2-(4-IODO-2,5-DIMETOXIFENIL)-N-[(2-METOXIFENIL)METIL]ETAMINA OU 25I-NBOME: CARACTERIZAÇÃO QUÍMICA DE UMA DESIGNER DRUG

Drug trafficking and the introduction of new drugs onto the illicit market are one of the main challenges of the forensic community. In this study, the chemical profile of a new designer drug, 2-(4-iodine-2,5-dimethoxyphenyl)-n-[(2-methoxyphenyl)methyl]etamine or 25I-NBOMe was explored using thin layer chromatography (TLC), ultraviolet-visible spectrophotometry (UV-Vis), attenuated total reflection with Fourier transform infrared spectroscopy(ATR-FTIR), gas chromatography mass spectrometry (GC-MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). First, the TLC technique was effective for identifying spots related to 25C-, 25B- and 25I-NBOMe compounds, all with the same retention factor, Rf ≈ 0.50. No spot was detected for 2,5-dimethoxy-4-bromoamphetamine, 2,5-Dimethoxy-4-chloroamphetamine or lysergic acid diethylamide compounds. ATR-FTIR preserved the physical-chemical properties of the material, whereas GC-MS and ESI-MS showed better analytical selectivity. ESI(+)FT-ICR MS was used to identify the exact mass (m/z428.1706 for the [M + H]+ ion), molecular formula (M = C18H22INO3), degree of unsaturation (DBE = 8) and the chemical structure (from collision induced dissociation, CID, experiments) of the 25I-NBOMe compound. Furthermore, the ATR-FTIR and CID results suggested the presence of isomers, where a second structure is proposed as an isomer of the 25I-NBOMe molecule.

Controle da ferrugem da folha e da mancha bronzeada da folha de trigo pelo uso de fungicidas em tratamento de sementes

The control of leaf rust and tan spot of wheat by seed treatment with fungicides was evaluated during 1998 in Passo Fundo, RS. Except for treatments including triadimenol and iprodione, leaf rust and tan spot severity in above ground parts of wheat plants was drastically reduced by the fluquinconazole fungicide used.

Mancha foliar e podridão de frutos da acerola causadas por Calonectria ilicicola

A new leaf spot and fruit rot disease is reported on barbados cherry (Malpighia glabra), occurring in the State of Maranhão, Brazil, caused by the fungus Calonectria ilicicola.

RT-PCR and Dot Blot hybridization methods for a universal detection of tospoviruses

Transcriptase reverse - polymerase chain reaction (RT-PCR) and dot blot hybridization with digoxigenin-labeled probes were applied for the universal detection of Tospovirus species. The virus species tested were Tomato spotted wilt virus, Tomato chlorotic spot virus, Groundnut ringspot virus, Chrysanthemum stem necrosis virus, Impatiens necrotic spot virus, Zucchini lethal chlorosis virus, Iris yellow spot virus. Primers for PCR amplification were designed to match conserved regions of the tospovirus genome. RT-PCR using distinct primer combinations was unable to simultaneously amplify all tospovirus species and consistently failed to detect ZLCV and IYSV in total RNA extracts. However, all tospovirus species were detected by RT-PCR when viral RNA was used as template. RNA-specific PCR products were used as probes for dot hybridization. This assay with a M probe (directed to the G1/G2 gene) detected at low stringency conditions all Tospovirus species, except IYSV. At low stringency conditions, the L non-radioactive probe detected the seven Tospovirus species in a single assay. This method for broad spectrum detection can be potentially employed in quarantine services for indexing in vitro germplasm.

Molecular and pathogenic variability of Drechslera isolates from oats

Severe epidemics of leaf blotch and black leaf spot of oat (Avena sativa) caused by Drechslera avenae and Drechslera sp., respectively, are frequently observed in the State of Paraná, Brazil. Although some morphological differences between the isolates causing two different symptoms were noticed, the genetic relationship between them was not clear. Twenty-four isolates of D. avenae and Drechslera sp, collected between 1996-98, were assessed for the genetic variability by molecular and pathogenic analyses. The amplification products using primer pair ITS4/ITS5 showed a fragment length of approximately 600 bp for all the isolates except for one black spot isolate, where the fragment length was approximately 550 bp. Restriction enzymes Hinf I and Taq I, that cut in the ITS region, produced similar restriction patterns for all the isolates, whereas four others produced variable restriction patterns. RAPD analysis also showed distinctive patterns for some isolates. No clear difference between the black spot and the leaf blotch isolates was observed either by the molecular or by the pathogenicity analysis. Nonetheless, the rDNA analysis suggests that Drechslera probably comprises at least three distinct taxa. The results indicate that the difference observed between the isolates originating from two types of symptoms is due to intra-specific variants of D. avenae.

Detection of drechslera avenae in oat seeds

The fungus Drechslera avenae, the causal agent of Helminthosporium leaf spot on oats (Avena sativa), survives as mycelium in crop residues and in infected seeds. In trials carried out in the laboratory, ten methods were evaluated for their efficiency to detect D. avenae in oat seeds. In each experiment, groups of two or three methods were compared to a standard protocol, in which seeds were placed in Petri dishes containing the Reis selective medium and incubated at 25±2 °C for ten days. Data were submitted to analysis of variation and the means of the methods were compared using the Dunnett test at the 5% significance level. Overall, the highest levels of seed infection by D. avenae were observed on oat seeds plated in the osmotic, the oat-agar and the Reis media, or on seeds subjected to heat treatment previous to incubation in malt-agar. Therefore, these methods should be recommended for detection of D. avenae in oat seed testing.

Identification of Phaeoisariopsis griseola pathotypes from five States in Brazil

Due to the increased importance of angular leaf spot of common bean (Phaseolus vulgaris) in Brazil, monitoring the pathogenic variability of its causal agent (Phaeoisariopsis griseola) is the best strategy for a breeding program aimed at developing resistant genotypes. Fifty one isolates of P. griseola collected in five Brazilian States were tested on a set of 12 international differential cultivars in the greenhouse. When inoculated plants showed symptoms but no sporulation was observed, they were transferred to a moist chamber for approximately 20-24 h. After this period of time, if no sporulation was observed, the plants were considered resistant; otherwise, they were considered susceptible. From the fifty-one tested isolates, seven different pathotypes were identified. No Andean pathotypes were identified; consequently, all isolates were classified as Middle American pathotypes. Pathotype 63-31 was the most widespread. Pathotype 63-63 overcame resistance genes present in all differential cultivars and also the resistance gene(s) present in the cultivar AND 277. This fact has important implications for breeding angular leaf spot resistance in beans, and suggests that searching for new resistance genes to angular leaf spot must be pursued.

Detection and partial characterization of an isolate of Groundnut ringspot virus in Solanum sessiliflorum

The cubiu (Solanum sessiliflorum) fruit, originating in the Amazon basin, is commonly used in that region for food, medicine, and cosmetics. In an experimental culture of cubiu, in order to evaluate its adaptation to conditions in the Northern region of the state of Rio de Janeiro, it was observed plants with mosaic symptoms. A cubiu plant was collected and analyzed to identify the etiological agent. After mechanical passage through a local lesion host, a host range test was performed. The virus induced chlorotic local lesions in Chenopodium quinoa, necrotic local lesions in Gomphrena globosa, mosaic in S. sessiliflorum, leaf and stem necrosis in tomato (Lycopersicon esculentum) 'Rutgers', mosaic and leaf distortion in Datura stramonium and Physalis floridana, and necrotic local lesions followed by systemic necrosis and plant death in four Nicotiana species. Electron microscopic observations of ultra thin sections from infected cubiu leaves showed the presence of spheroidal, membrane-bound particles typical of tospovirus species. Analysis of the nucleocapsid protein from concentrated virus particles indicated the presence of a 28 kDa protein. RT-PCR was performed after total RNA extraction from infected IPA-6 tomato leaves. A fragment of approximately 0,8 kbp corresponding to the N gene was amplified, cloned and sequenced. The N protein from the cubiu isolate was 95% homologous to the Groundnut ringspot virus (GRSV) protein, and no more than 85% homologous to those from Zucchini lethal chlorosis virus (ZLCV) and Chrysanthemun stem necrosis virus (CSNV), Tomato spotted wilt virus (TSWV), and Tomato chlorotic spot virus (TCSV). This is the first report of the occurrence of GRSV (or any other plant virus) in cubiu.

RT-PCR-ELISA for detection of Apple stem grooving virus in apple trees

A method to detect Apple stem grooving virus (ASGV) based on reverse transcription polymerase chain reaction (RT-PCR) was developed using primers ASGV4F-ASGV4R targeting the viral replicase gene, followed by a sandwich hybridisation, in microtiter plates, for colorimetric detection of the PCR products. The RT-PCR was performed with the Titan™ RT-PCR system, using AMV and diluted crude extracts of apple (Malus domestica) leaf or bark for the first strand synthesis and a mixture of Taq and PWO DNA polymerase for the PCR step. The RT-PCR products is hybridised with both a biotin-labelled capture probe linked to a streptavidin-coated microtiter plate and a digoxigenin (DIG)-labelled detection probe. The complex was detected with an anti-DIG conjugate labelled with alkaline phosphatase. When purified ASGV was added to extracts of plant tissue, as little as 400 fg of the virus was detected with this method. The assay with ASGV4F-ASGV4R primers specifically detected the virus in ASGV-infected apple trees from different origins, whereas no signal was observed with amplification products obtained with primers targeting the coat protein region of the ASGV genome or with primers specific for Apple chlorotic leaf spot virus (ACLSV) and Apple stem pitting virus (ASPV). The technique combines the power of PCR to increase the number of copies of the targeted gene, the specificity of DNA hybridization, and the ease of colorimetric detection and sample handling in microplates.

Three new pathogens infecting antilles cherry in the State of Pará

When grown in monoculture, Antilles cherry (Malpighia glabra) plants have been affected by diseases which cause fruits malformation and spotting, reducing their value for market. From 1999 on, three new diseases characterised by leaf spot and fall of leaves have been observed in plantations located in Santa Izabel do Pará and Igarapé Açu counties. After isolation and pathogenicity tests on leaves of Antilles cherry plants, the isolates were identified as Calonectria ilicicola (anamorph: Cylindrocladium parasiticum) which causes large leaf spots reaching up to 7 cm long, brownish in colour, coalescent, scorching large leaf areas and causing 50% of leaf fall; Corynespora cassiicola, which provokes irregularly shaped, necrotic leaf spots with dark brown margins and white centers, surrounded by a yellow halo; and Myrothecium roridum which causes greyish target spots. Corynespora cassiicola has been reported causing leaf spots on different hosts in the Amazon region, while C. cassiicola has been recorded infecting Antilles cherry besides other hosts in the States of Maranhão and Pará.

Ocorrência de Bipolaris maydis causando mancha foliar em Paspalum atratum cv. Pojuca no Brasil

Bipolaris maydis was consistently isolated from infected Paspalum atratum cv. Pojuca plants showing leaf spot symptoms in the Cerrado of Brazil, in 2002. Pathogenicity tests under greenhouse conditions and subsequent reisolations of B. maydis from artificially inoculated Pojuca seedlings confirmed the hypothesis that this fungus was the causal agent of the disease. Symptoms of leaf spot appeared four days after inoculation in 100% of the inoculated Pojuca plants. All seven species of grasses evaluated were susceptible to B. maydis. The occurrence of leaf spot of Pojuca caused by B. maydis is reported for the first time in Brazil.

Quantitative analysis of two important epidemiological features of the common bean: Phaeoisariopsis griseola pathosystem

This work quantifies two important epidemiological features of the bean (Phaseolus vulgaris)/Phaeoisariopsis griseola pathosystem. The first is the effect of the number of nights of leaf wetness on infection efficiency. Infection efficiency was below 10% when inoculated leaflets were exposed to less than two nights of leaf wetness. Optimum infection efficiencies were obtained after three to four nights of leaf wetness, at about 50%. Further nights of leaf wetness did not increase the infection efficiency. The second feature quantified is the relative rate of leaflet defoliation for varying levels of angular leaf spot severity. It increased with disease severity according to a logarithm-like curve, and a relative rate of 0.23 day-1 was estimated for a severity of 18%. The implications of these results on the disease epidemiology are discussed.

Silicon and rice disease management

The element silicon (Si) is not considered an essential nutrient for plant function. Nevertheless, Si is absorbed from soil in large amounts that are several fold higher than those of other essential macronutrients in certain plant species. Its beneficial effects have been reported in various situations, especially under biotic and abiotic stress conditions. The most significant effect of Si on plants, besides improving their fitness in nature and increasing agricultural productivity, is the restriction of parasitism. There has been a considerable amount of research showing the positive effect of Si in controlling diseases in important crops. Rice (Oryza sativa), in particular, is affected by the presence of Si, with diseases such as blast, brown spot and sheath blight becoming more severe on rice plants grown in Si-depleted soils. The hypothesis underlying the control of some diseases in both mono- and di-cots by Si has been confined to that of a mechanical barrier resulting from its polymerization in planta. However, some studies show that Si-mediated resistance against pathogens is associated with the accumulation of phenolics and phytoalexins as well as with the activation of some PR-genes. These findings strongly suggest that Si plays an active role in the resistance of some plants to diseases rather than forming a physical barrier that impedes penetration by fungal pathogens.

A Semi-Selective agar medium to detect the presence of Xanthomonas axonopodis pv. malvacearum in naturally infected cotton seed

A semi-selective agar medium was developed for detection of Xanthomonas axonopodis pv. malvacearum (Xam) in cotton (Gossypium hirsutum) seed. The basic medium was peptone-sucrose-agar (PSA). Criteria for the semi-selective medium were the typical colony characters of Xam and its pathogenicity on cotton. Several systemic fungicides and antibiotics in different concentrations were tested alone or in combination with others. The final composition of the semi-selective agar medium was established after several attempts in order to inhibit most of the fungal and bacterial saprophytes and favour the development of Xam. It contained PSA + cyclohexamide, cephalexin, pencycuron, triadimenol and tolylfluanid. The bacteria were recovered from naturally infected seeds by the direct plating of 2,000 surface disinfected seeds on the semi-selective medium. The recovery of the pathogen from naturally infected leaf tissues and in dilution plating, on semi-selective medium and on nutrient agar, were comparable. Among the three detection methods tested, the semi-selective medium was found to be the most reliable and quantifiable. Degree of severity of angular leaf spot in the field was not always correlated with the level of infection in the seed. This is the first report of a semi-selective agar medium to detect the presence of Xam in naturally infected cotton seed.

Effect of extracts from citric biomass, rusted coffee leaves and coffee berry husks on Phoma costarricencis of coffee plants

Phoma leaf spot, caused by Phoma costarricensis poses a serious threat to coffee (Coffea arabica) production, especially in the highlands of the state of Minas Gerais, Brazil. Extracts of citric biomass, coffee berry husks and coffee leaves severely affected by rust caused by Hemileia vastatrix, were evaluated against P. costarricensis. In an in vitro assay, aqueous extracts of rusted leaves and berry husks plus the commercial extracts based on citric biomass named Ecolife® and Agromil® were tested at various dilutions on the mycelial growth inhibition of P. costarricensis. In vivo, coffee seedlings maintained in glasshouse, were sprayed with these extracts seven days before inoculation of P. costarricensis. Only extracts from citric biomass had inhibitory effects on the fungus. In vivo, Ecolife® (5 ml/l), Agromil® (5 g/l) and the aqueous extract of rusted coffee leaves (dilution 1:6) reduced Phoma leaf spot. Both, Ecolife® and the extract of rusted coffee leaves were significantly more effective in reducing the area under the lesion progress curve when applied at lower doses, indicating a possible effect on the induction of resistance.