Metal location and thickness in a multilayered sheet by measuring K alpha/K beta, L alpha/L beta and L alpha/L gamma X-ray ratios

When a multilayered material is analyzed by means of energy-dispersive X-ray fluorescence analysis, then the X-ray ratios of K alpha/K beta, or L alpha/L beta and L alpha/L gamma, for an element in the multilayered material, depend on the composition and thickness of the layer in which the element is situated, and on the composition and thickness of the superimposed layer (or layers). Multilayered samples are common in archaeometry, for example, in the case of pigment layers in paintings, or in the case of gilded or silvered alloys. The latter situation is examined in detail in the present paper, with a specific reference to pre-Columbian alloys from various museums in the north of Peru. (C) 2009 Elsevier B.V. All rights reserved.

Enraizamento de estacas de Camellia sinensis L. em função da época de coleta de ramos, genótipos e ácido indolbutírico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de tangerinas, tangores e tangelos em relação à clorose variegada dos citros

A Clorose Variegada dos Citros (CVC), causada pela bactéria Xylella fastidiosa, é uma séria ameaça à citricultura brasileira, constituindo-se, atualmente, numa das principais doenças dos citros no Brasil. O objetivo desse trabalho foi avaliar cultivares de citros introduzidas quanto à suscetibilidade ou resistência à CVC, em condições de campo. O trabalho foi conduzido em Bebedouro-SP. Os materiais genéticos estudados foram cultivares de tangerinas e híbridos (tangores e tangelos) introduzidas de bancos de germoplasma da Itália, Portugal, Espanha e Córsega. O trabalho foi constituído por 56 parcelas, com três plantas das quais uma foi inoculada, empregando-se o método de encostia, utilizando-se de mudas previamente infectadas como fontes da bactéria. Foram avaliados os sintomas da doença mediante observação visual através de notas e teste de PCR, específico para Xylella fastidiosa. Os materiais genéticos que se apresentaram positivos ao PCR, mas não apresentaram sintomas, e os que foram negativos ao PCR, possuem um potencial de utilização em programas de melhoramento genético visando à resistência e/ou à tolerância à doença.

Formação do pomar de tangerina 'Poncã', em função da adubação química e orgânica

Avaliou-se o efeito do esterco de curral curtido na adubação de formação do pomar de tangerineira 'Poncã' (Citrus reticulata, Blanco), comparando com a adubação química convencional. O experimento foi conduzido na Fazenda Experimental São Manuel da Faculdade de Ciências Agronômicas da UNESP, Câmpus de Botucatu-SP. Os tratamentos foram aplicados na adubação de formação do pomar durante dois anos. No primeiro ano, utilizaram-se 7,5; 15,0; 22,5 e 30,0 kg planta-1 de esterco de curral curtido e 400 g planta-1 de sulfato de amônio. Na adubação de formação do segundo ano, as doses de esterco de curral foram 15,0; 22,5; 30,0 e 37,5 kg planta-1 e 800 g planta-1 de sulfato de amônio. Nos dois anos, a adubação foi parcelada em três aplicações. Realizaram-se as avaliações aos 30; 150 e 270 dias após a última parcela de adubação do segundo ano, determinando-se: altura da planta, diâmetro do caule, volume, projeção e circunferência da copa. O delineamento experimental foi inteiramente casualizado, em parcelas subdivididas no tempo, e 3 repetições, sendo as parcelas representadas pela adubação e as subparcelas pelas épocas de avaliação. Verificou-se que, na média das avaliações, houve aumento linear das características avaliadas com o incremento das doses de esterco de curral curtido. Não houve diferença significativa entre os tratamentos com adubo orgânico e químico.

Search for associated Higgs boson production WH -> WWW*-> l(+/-)nu l('+/-)nu(')+X in p(p)over-bar collisions at root S=1.96 TeV

We present a search for associated Higgs boson production in the process p (p) over bar -> WH -> WWW*-> l(+/-)nu l('+/-)nu(')+X in final states containing two like-sign isolated electrons or muons (e(+/-)e(+/-), e(+/-)mu(+/-), or mu(+/-)mu(+/-)). The search is based on D0 run II data samples corresponding to integrated luminosities of 360-380 pb(-1). No excess is observed over the predicted standard model background. We set 95% C.L. upper limits on sigma ->(p (p) over bar WH) x Br(H -> WW*) between 3.2 and 2.8 pb for Higgs boson masses from 115 to 175 GeV.

Biologia de Ceratobasidium spp. associada à doença queima dos fios no chá (Camellia sinensis L.)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Atividade anti-inflamatória e citotoxicidade dos extratos glicólicos de Cynara cardunculus var. scolymus (L.) Fiori (alcachofra), Myracrodruon urundeuva Allemão (aroeira-do-sertão) e Camellia sinensis (L.) Kuntze (chá verde)

Pós-graduação em Biopatologia Bucal - ICT

Enraizamento de estacas de Camellia sinensis L. em função da época de coleta de ramos, genótipos e ácido indolbutírico

Objetivou-se avaliar o efeito da época de coleta de ramos, genótipo e concentração de ácido indolbutírico (AIB) no enraizamento de estacas de Camellia sinensis L. Para tal, foram coletados ramos dos genótipos IAC 259, F 15 e Comum, em Pariquera-Açu, SP, Brasil, no inverno, primavera, verão e outono. em seguida, foram preparadas estacas que foram tratadas com AIB (0, 2.000, 4.000, 6.000 e 8.000 e 10.000mg L-1), plantadas em vermiculita e mantidas em viveiro sob 70% de sombreamento e irrigação periódica. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 4x3x6 (quatro épocas, três genótipos e seis concentrações de AIB), com quatro repetições de oito estacas. A época ideal para se coletar os ramos foi o inverno. Estacas coletadas no inverno apresentaram mortalidade média de 41%, enquanto nas estacas vivas o enraizamento médio foi de 66%, influenciado apenas pelo genótipo, todas apresentaram brotações e apenas 32% apresentaram calos. O AIB influenciou o número e o comprimento das raízes formadas em estacas no inverno. Na primavera, apesar da menor mortalidade (31%), apenas 0,34% das estacas vivas apresentaram raiz e 49% brotação, enquanto 97% das estacas apresentaram calo. No verão e outono a mortalidade das estacas foi extremamente alta, respectivamente, 93 e 81% das estacas.

Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts

The objective of this study was to produce citrus somatic asymmetric hybrids by fusing gamma-irradiated protoplasts with iodoacetamide-treated protoplasts. Protoplasts were isolated from embryogenic suspension cells of grapefruit (Citrus paradisi Macfad.) cultivars Ruby Red and Flame, sweet oranges (C. sinensis Osbeck) 'Itaboraí', 'Natal', Valencia', and 'Succari', from 'Satsuma' (C. unshiu Marcow.) and 'Changsha' mandarin (C. reticulata Blanco) and 'Murcott' tangor (C. reticulata x C. sinensis). Donor protoplasts were exposed to gamma rays and receptor protoplasts were treated with 3 mmol L-1 iodoacetamide (IOA), and then they were fused for asymmetric hybridization. Asymmetric embryos were germinated, and the resulting shoots were either grafted onto sour orange, rough lemon or 'Swingle' (C. paradisi x Poncirus trifoliata) x 'Sunki' mandarin rootstock seedlings, or rooted after dipping their bases in indol-butyric acid (IBA) solution. The products were later acclimatized to greenhouse conditions. Ploidy was analyzed by flow cytometry, and hybridity was confirmed by amplified fragment length polymorphism (AFLP) analysis of plantlet DNAsamples. The best treatment was the donor-recipient fusion combination of 80 Gy-irradiated 'Ruby Red' protoplasts with 20 min IOA-treated 'Succari' protoplasts. Tetraploid and aneuploid plants were produced. Rooting recalcitrance was solved by dipping shoots' stems in 3,000 mg L-1 IBA solution for 10 min.

Susceptibility of tangerines to citrus variegated chlorosis

Citrus variegated chlorosis (CVC), a citrus disease first discovered in Brazil in 1987, is caused by the bacterium Xylella fastidiosa and transmitted by sharpshooters and budwood. Since the disease affects almost all sweet orange cultivars, it has become one of the most serious problems for Brazilian citriculture. To evaluate their resistance to CVC disease, fifteen tangerines or mandarins (C. reticulata Blanco) and their hybrids were grafted on Rangpur lime (C. limonia Osb.) and inoculated with CVC-contaminated Pera sweet orange (C. sinensis (L.) Osb.) by twig grafting in a greenhouse. Tangerines and their hybrids Wilking, Fortune, Sunki, Ellendale, Orlando tangelo, Nunes clementine, Nova, Sun Shu Sha Kat, Suenkat, and Batangas showed CVC leaf symptoms and gave positive results on enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) (with specific primers for X. fastidiosa), indicating that they are susceptible to CVC. Although X. fastidiosa bacteria were detected by ELISA and PCR in inoculated plants of tangerines Cravo and Oneco, no CVC leaf symptoms were observed on these two cultivars, suggesting that they are tolerant to the disease. CVC leaf symptoms were not observed and X. fastidiosa was not detected in tangerine Dancy and mandarins Okitsu satsuma and Ponkan after inoculation, showing that they are resistant to the disease.

Metabolite profiles of essential oils in citrus peels and their taxonomic implications

China is an important center of origin for the genus Citrus L. of the family Rutaceae and is rich in wild Citrus species. The taxonomy of Citrus has been a subject of controversy for more than a half century. We propose that the metabolite profiles of Chinese native Citrus species can be used for classification and understanding of the taxonomic relationships within the Citrus germplasm. In this study, triplicate gas chromatography-mass spectrometry (GC-MS) metabolite profiles of 20 Citrus species/varieties were acquired, including 10 native varieties originating in China. R-(+)-limonene, alpha-pinene, sabinene and alpha-terpinene were found to be major characteristic components of the essential oils analyzed in this study, and these compounds contributed greatly to the metabolic classification. The three basic species of the subgenus Eucitrus (Swingle's system), i.e., C. reticulata Blanco, C. medica L. and C. grandis Osb., were clearly differentiated based upon their metabolite profiles using hierarchical cluster analysis (HCA) and partial least square-discriminant analysis (PLS-DA). All the presumed hybrid genotypes, including sweet orange (C. sinensis Osb.), sour orange (C. aurantium L.), lemon (C. limon Burm.f.), rough lemon (C. jambhiri Lush.), rangpur lime (C. limonia Osb.) and grapefruit (C. paradisi Macf.), were grouped closely together with one of their suggested parent species in the HCA-dendrogram and the PLS-DA score plot. These results clearly demonstrated that the metabolite profiles of Citrus species could be utilized for the taxonomic classification of the genus and are complementary to the existing taxonomic evidence, especially for the identification and differentiation of hybrid species.

Genetic transformation of Citrus sinensis cv. Hamlin with hrpN gene from Erwinia amylovora and evaluation of the transgenic lines for resistance to citrus canker

Transgenic Citrus sinensis (L.) Osb. cv. Hamlin plants expressing the hrpN gene were obtained by Agrobacterium tumefaciens (Smith and Towns) Conn-mediated transformation. hrpN encodes a harpin protein, which elicits the hypersensitive response and systemic acquired resistance in plants. The gene construct consisted of gst1, a pathogen-inducible promoter, a signal peptide for protein secretion to the apoplast, the selection genes nptI1 or aacC1 and the Nos terminator. The function of gst1 in citrus was evaluated in transgenic C. sinensis cv. Valencia harboring the reporter gene uidA (gus) driven by this promoter. Histochemical analysis for gus revealed that gst1 is activated in citrus leaves by both wounding and inoculation with Xanthomonas axonopodis Starr and Garces pv. citri (Hasse) Vauterin et al. Genetic transformation was confirmed by Southern blot hybridization in eight cv. Hamlin acclimatized plants. RT-PCR confirmed hrpN gene expression in seven cv. Hamlin transgenic lines before pathogen inoculation. Some hrpN transgenic lines showed severe leaf curling and abnormal growth. Six hrpN transgenic lines were propagated and evaluated for susceptibility to X axonopodis pv. citri. RT-PCR confirmed gene expression in all six hrpN transgenic lines after pathogen inoculation. Several of the hrpN transgenic lines showed reduction in susceptibility to citrus canker as compared with non-transgenic plants. One hrpN transgenic line exhibited normal vegetative development and displayed very high resistance to the pathogen, estimated as up to 79% reduction in disease severity. This is the first report of genetic transformation of citrus using a pathogen-inducible promoter and the hrpN gene. Further evaluations of the transgenic plants under field conditions are planned. Nevertheless, the evidence to date suggests that the hrpN gene reduces the susceptibility of citrus plants to the canker disease. (C) 2009 Elsevier B.V. All rights reserved.

Endophytic population of Pantoea agglomerans in citrus plants and development of a cloning vector for endophytes

Harmless bacteria inhabiting inner plant tissues are termed endophytes. Population fluctuations in the endophytic bacterium Pantoea agglomerans associated with two species of field cultured citrus plants were monitored over a two-year period. The results demonstrated that populations of P. agglomerans fluctuated in Citrus reticulata but not C. sinensis. A cryptic plasmid pPA3.0 (2.9 kb) was identified in 35 out of 44 endophytic isolates of P. agglomerans and was subsequently sequenced. The origins of replication were identified and nine out of 18 open reading frames (ORFs) revealed homology with described proteins. Notably, two ORFs were related to cellular transport systems and plasmid maintenance. Plasmid pPA3.0 was cloned and the gfp gene inserted to generate the pPAGFP vector. The vector was introduced into P. agglomerans isolates and revealed stability was dependent on the isolate genotype, ninety-percent stability values were reached after 60 hours of bacterial cultivation in most evaluated isolates. In order to definitively establish P. agglomerans as an endophyte, the non-transformed bacterium was reintroduced into in vitro cultivated seedlings and the density of inner tissue colonization in inoculated plants was estimated by bacterium re-isolation, while the tissue niches preferred by the bacterium were investigated by scanning electronic microscopy (SEM). Cells from P. agglomerans (strain ARB18) at similar densities were re-isolated from roots, stems and leaves and colonization of parenchyma and xylem tissues were observed. Data suggested that P. agglomerans is a ubiquitous citrus endophyte harboring cryptic plasmids. These characteristics suggest the potential to use the bacterium as a vehicle to introduce new genes in host plants via endophytic bacterial transformation.

Desempenho de diferentes estádios embrionários no cultivo in vitro de embriões de 'Pêra Rio' x 'Poncã'

Objetivou-se verificar qual o melhor estádio embrionário para o cultivo de embriões imaturos oriundos de frutos provenientes de hibridação entre 'Pêra Rio' x 'Poncã' , bem como o efeito de diferentes concentrações do meio de cultura MT. Os embriões em diferentes estádios de desenvolvimento (globulares, torpedo e cordiforme) foram excisados e inoculados em tubos de ensaio contendo 15 mL do meio MT com diferentes concentrações (0; 50; 100 e 150% da composição original e acrescido de 50 g.L-1 de sacarose). Após a inoculação, os embriões foram incubados à 27±1ºC, fotoperíodo de 16 horas e irradiância de 32 mmol.m-2.s-1. Após 90 dias, avaliou-se o comprimento da parte aérea e do sistema radicular, massa fresca e número de folhas das plântulas. Melhor desenvolvimento dos embriões imaturos foi obtido em estádio cotiledonar e com a concentração de 150% do meio MT.

Parasitóides de lepidópteros minadores presentes em plantas de crescimento espontâneo em pomar orgânicos de citrus montenegro - RS

Este trabalho teve como objetivos verificar se Phyllocnistis citrella ataca plantas de crescimento espontâneo, presentes em pomar de citros orgânicos, identificar nestas plantas outros lepidópteros minadores e seus parasitóides, e verificar se estes parasitóides são os mesmos relatados para P. citrella. O trabalho foi conduzido no município de Montenegro-RS, em um pomar orgânico do híbrido 'Murcott' (Citrus sinensis x C. reticulata). Realizaram-se amostragens quinzenais, de maio de 2003 a maio de 2004, coletando-se, em cada ocasião, todas as folhas com minas contidas na área delimitada por um aro de 0,28 m², que era jogado nas linhas e nas entrelinhas de 30 árvores sorteadas. O material coletado foi levado ao laboratório para triagem. Durante o estudo, foram registradas 11 espécies de lepidópteros minadores e 12 espécies de microimenópteros parasitóides. Alguns gêneros identificados neste estudo já haviam sido relatados em várias regiões do mundo com espécies parasitando P. citrella, tais como Chrysocharis, Closterocerus, Sympiesis (Hymenoptera: Eulophidae) e Bracon (Hymenoptera: Braconidae).