ABSTRACT The objective of this study was to evaluate the virulence of Pyricularia oryzae isolates obtained from a single leaf blast lesion on wheat. The wheat cultivars (BRS Louro, BR 18, BRS Tarumã, BRS Parrudo, BRS 208) at the four-leaf stage were inoculated with a suspension of 100.000 conidia/mL. A significant difference was observed in the severity in the cultivars. Among the evaluated isolates, it was possible to observe differences in the susceptibility of the cultivars. Severity data ranged from 3.3 to 99.54% among treatments. Isolates 1 and 2 were the most aggressive for all cultivars tested. The greatest disease severity occurred in the interactions BRS 208 x isolate 1 (99.54%), BRS Louro x isolate 2 (99.34%), and BRS 208 x isolate 2 (99.09%).The lowest disease severity was observed in BRS Tarumã (68%) and BR 18 (75%) cultivars for the isolates 1 and 2, respectively. Isolate 3 presented medium aggressiveness in which the cultivars presented between 44 to 58% of wheat blast severity. The isolate 4 was the least aggressive for all cultivars with severity indexes ranging from 3 to 12%. These data indicate the existence of virulence diversity in P. oryzae isolates obtained from a single lesion.

Blast, caused by Pyricularia oryzae, has become a significant disease threat to wheat (Triticum aestivum L.) in Brazil. This study aimed to investigate at the histochemical level if silicon (Si) could enhance the production of flavonoids in the leaves of wheat plants in response to P. oryzae infection. Plants from the Aliança cultivar, which are susceptible to blast, were grown in hydroponic cultures containing 0 (-Si) or 2 mM of Si (+Si) and inoculated by spraying a conidial suspension of P. oryzae (1 × 105 conidia mL−1) on all adaxial leaf surfaces of plants at 60 days after emergence (growth stage 65). The fourth and fifth leaves of each plant were used to evaluate blast severity at 24, 36, 48, 72 and 96 h after inoculation (hai). At 96 hai, leaves were collected from plants to determine the foliar Si concentration. For cytological observations, leaf samples were randomly collected from the fourth and fifth leaves of each plant at 72 hai. The foliar Si concentration was higher in +Si plants (36 g kg−1) in comparison to -Si plants (2.6 g kg−1). This increased Si concentration was correlated with reduced fungal growth inside the epidermal cells and the development of blast symptoms on leaves. Strong fluorescence, which is an indication of the presence of flavonoids, was detected in the leaf cells of +Si plants using Neu’s and Wilson's reagents. A novel item of evidence is that, at the histochemical level, Si is involved in the potentiation of the biosynthetic pathway of flavonoids that increases wheat resistance to blast.

Considering the importance of blast, caused by Pyricularia oryzae, to reduce wheat yield, this study investigate how silicon (Si) could reduce the wheat blast symptoms in the rachis tissues using light microscopy and scanning electron microscopy. Wheat plants (cv. BR 18) were grown in hydroponic culture with either 0 (–Si) or 2 mM (+Si) of Si. Blast symptoms were very well developed on the spikes of the –Si plants, which showed intense discoloration in contrast with the spikes of the +Si plants. At 72 hours after inoculation (hai), fungal hyphae extensively colonized the epidermis and the collenchyma tissue in the radial direction in the rachis of the –Si plants. In the +Si plants, fungal hyphae colonized the epidermis and the collenchyma cells to a lesser extent than in the –Si plants. At 96 hai, fungal hyphae were observed in the epidermis, vascular bundles and cortical tissue in the rachis node of the -Si plants. In the +Si plants, a phenolic-like material was detected in the parenchyma with lower fungal colonization in comparison with the –Si plants. In scanning electron microscopy, fungal hyphae were scarcely observed in the upper epidermal, collenchyma and parenchyma cells in the rachis tissue of the +Si plants, whereas in the rachis tissue of the –Si plants, fungal hyphae extensively colonized the epidermis, collenchyma, parenchyma and vascular bundles.

A antracnose, causada pelo fungo Colletotrichum lindemuthianum, é uma das doenças mais destrutivas que afetam a cultura do feijoeiro. Com o objetivo de encontrar alternativas para o controle dessa doença, o presente trabalho investigou, em nível microscópico, o efeito do silício (Si) na resistência do feijoeiro à infecção por C. lindemuthianum. Plantas de feijoeiro (cv. Pérola) foram cultivadas em solução nutritiva contendo 0 (-Si) ou 2 mM (+Si) de Si e inoculadas no estádio de crescimento V4 com uma suspensão de conídios de C. lindemuthianum. A severidade da antracnose decresceu cerca de 52% nas folhas das plantas supridas com Si (4,4%) em relação às folhas das plantas não supridas (8,5%). Observações de folhas de feijoeiro das plantas não supridas com Si no microscópio eletrônico de varredura revelaram alterações morfológicas nas nervuras em contraste com as folhas de plantas supridas com Si. Utilizando-se a microanálise de raios-X, verificou-se maior concentração dos minerais enxofre, potássio e Si nas folhas das plantas supridas com Si. Em conclusão, o suprimento de Si em plantas de feijoeiro foi importante para reduzir os sintomas da antracnose.

The anthracnose, caused by the fungus Colletotrichum lindemuthianum, is one of the most destructive diseases affecting bean crop. With the objective to find alternative to the control this disease, this study investigated, at the microscopic level, the effect of silicon (Si) on bean resistance to infection by C. lindemuthianum. Bean plants (cv. 'Pérola') were grown in nutrient solution containing 0 (-Si) or 2 mM (+ Si) of Si and inoculated in the V4 growth stage with a suspension of conidia of C. lindemuthianum. The disease severity decreased by 52% in the leaves of plants supplied with Si (4.4%) in relation to the leaves of non supplied plants (8.5%). Observations of bean leaves of plants not supplied with Si by scanning electron microscopy revealed morphological changes in the veins in contrast with the leaves of plants supplied with Si. By using the X-ray microanalysis, it was found higher concentrations of the minerals sulfur, potassium and Si in the leaves of plants supplied with Si. In conclusion, the supply of Si in bean plants was important to reduce the symptoms of anthracnose.

O objetivo deste trabalho foi identificar SNPs em genes associados ao conteúdo de ácidos graxos em soja e implementar a metodologia "high resolution melting" (HRM) para genotipagem desses SNPs. Os iniciadores HRM foram desenhados para discriminar os alelos SNPs em duas populações de mapeamento (RILs e F2) e seguiram o padrão esperado de segregação. Os SNPs do gene ABI associaram-se significativamente ao conteúdo de ácido esteárico (R² = 12,14), e os do gene FAD3B, aos conteúdos de ácido oleico (R² = 14,69) e linolênico (R² = 10,62). A técnica de genotipagem dos SNPs por HRM é eficiente na discriminação das classes genotípicas.

The objective of this work was to identify SNPs in genes associated with fatty acid content in soybean and to implement the high resolution melting (HRM) technique for SNP genotyping. HRM primers were designed to discriminate SNP alleles in two mapping populations (RILs and F2) and followed the expected pattern of segregation. The ABI gene SNPs were significantly associated with stearic acid content (R² = 12.14), and the ones from the FAD3B gene, with oleic (R² = 14.69) and linolenic acid (R² = 10.62) contents. The technique of genotyping SNPs by HRM is efficient to discriminate genotype classes.

Blast, caused by Pyricularia oryzae, has become one of the most important diseases on wheat in Brazil. Knowing the beneficial effects of silicon (Si) in reducing rice blast severity, this study aimed to examine the cytological events occurring during the infectious process of P. oryzae on the leaves of wheat plants non-supplied (-Si) or supplied (+Si) with Si in an experiment arranged in a completely randomized design. The high foliar Si concentration for the +Si plants contributed to decrease the blast symptoms. Hyphae of P. oryzae grew successfully and formed an extensively branched mycelium in the first-invaded epidermal cell and invaded several neighboring cells on the -Si plants, while on the +Si plants fungal hyphae was restricted to the first-invaded epidermal cell. The number of brown adaxial epidermal cells and their intensity of browning were significantly lower for the +Si plants in comparison to the -Si plants. The frequency of appressorial sites showing type B reaction (infection hyphae within the epidermal cell and absence of cytoplasm granulation) was lower for the +Si plants than for the -Si plants from 72 to 96 hours after inoculation because the frequency of appressorial sites showing type A reaction (unsuccessful penetration) was kept higher in comparison to the -Si plants. This study provides novel cytological evidence of the negative effect of Si on the infection process of P. oryzae on leaves of wheat plants contributing, therefore, to reduce the blast symptoms.

The objective of this study was to understand the infection process of Fusarium oxysporum f. sp. phaseoli (Fop) in bean cultivars classified as resistant (Manteigão Fosco 11), intermediate (VP8) and susceptible (Meia Noite). Plants of the three cultivars were inoculated at 10 days after emergence with a suspension of 1×10(6) conidia of Fop per mL. At 43 days after the inoculation, stem segments were observed with a scanner electronic microscope. The cultivars Manteigão Fosco 11 and VP8 presented an occluding material in the xylem vessels, which may have restricted tissue colonization by Fop. The resistance of bean cultivars to Fop seemed also to be explained by structural differences in the xylem tissue.

Este estudo objetivou determinar o efeito do ácido jasmônico (AJ), do Acibenzolar-S-Metil (ASM) e do silicato de cálcio (fonte de silício solúvel, Si) na potencialização da resistência da soja à ferrugem asiática (FA). A severidade da FA foi significativamente reduzida nas plantas pulverizadas com ASM ou supridas com Si em comparação com as plantas pulverizadas com água deionizada ou AJ. Para a atividade das quitinases (QUI), diferenças significativas entre plantas não inoculadas e inoculadas que foram pulverizadas com água destilada ou ASM ocorreram às 72 horas após a inoculação (hai); às 24 e 72 hai para plantas pulverizadas com AJ e às 141 hai quando supridas com Si. Para β-1,3-glucanases (GLU), diferenças significativas entre plantas inoculadas e não inoculadas que foram pulverizadas com água deionizada ocorreram às 24, 48 e 141 hai, mas não ocorreram até as 72 hai para plantas pulverizadas com ASM. Para fenilalanina amônia-liases (PAL), houve diferença significativa na atividade entre plantas inoculadas e não inoculadas somente para aquelas pulverizadas com ASM as 72 e 141 hai. Em conclusão, os sintomas da FA podem ser reduzidos em plantas pulverizadas com ASM ou em plantas supridas com Si, em parte, pela participação das enzimas de defesa estudadas.

This study aimed to determine the effect of jasmonic acid (JA), Acibenzolar-S-Methyl (ASM) and calcium silicate (a source of soluble silicon, Si), on the potentiation of soybean resistance to Asian soybean rust (ASR). The ASR severity was significantly reduced on plants sprayed with ASM or supplied with Si in comparison to plants sprayed with JA or deionized water. For chitinases (CHI), significant differences in activity between non-inoculated and inoculated plants sprayed with deionized water or with ASM occurred at 72 hours after inoculation (hai), at 24 and 72 hai when sprayed with JA and at 141 hai when supplied with Si. For β-1,3-glucanases (GLU), significant differences in activity between non-inoculated and inoculated plants sprayed with deionized water occurred at 24, 48 and 141 hai, but not until 72 for plants sprayed with ASM. For phenylalanine ammonia-lyases (PAL), significant differences in activity between non-inoculated and inoculated plants occurred only for plants sprayed with ASM at 72 and 141 hai. In conclusion, the ASR symptoms can be mild on plants sprayed with ASM or supplied with Si and that this amelioration likely involved the defense enzymes.

O controle da Ferrugem Asiática da Soja (FAS), causado pelo fungo Phakopsora pachyrhizi, tem sido difícil devido à agressividade do patógeno e pela falta de cultivares resistentes. O objetivo deste estudo foi avaliar os efeitos da pulverização com silicato de potássio (SP) e do suprimento de Si via silicato de cálcio (SC) no solo sobre a resistência da soja à FAS. A solução de PS foi pulverizada nas folhas 24 horas antes da inoculação, enquanto que o SC foi aplicado no solo 35 dias antes da semeadura. O processo infeccioso de P. pachyrhizi foi investigado por microscopia eletrônica de varredura. As urédias nas folhas das plantas pulverizadas com SP foram menores e mais compactas do que as observadas nas folhas das plantas cultivadas em solo contendo SC ou em solo não contendo SC (tratamento controle). Nas folhas das plantas do tratamento controle, as urédias produziram muitos uredosporos aos nove dias após inoculação e a severidade da FAS foi de 15, 8 e 9% para as plantas dos tratamentos controle, SP e SC, respectivamente. Em conclusão, a pulverização de SP contribuiu para reduzir o número de urédias cm-2 da área foliar e ambas, a pulverização com SP e a aplicação do SC, resultaram na redução dos sintomas da FAS.

The control of Asian Soybean Rust (ASR), caused by Phakopsora pachyrhizi, has been difficult due to the aggressiveness of the pathogen and the lack of resistant cultivars. The objective of this study was to evaluate the effects of spray of potassium silicate (PS) and soil amendment with calcium silicate (CS) on soybean resistance to ASR. The PS solution was sprayed to leaves 24 hours prior to fungal inoculation while CS was amended to the soil at thirty-five days before sowing. The infection process of P. pachyrhizi was investigated by scanning electron microscopy. The uredia on leaves of plants sprayed with PS were smaller and more compact than those observed on the leaves of plants grown in soil amended with CS or in soil non-amended with CS (control treatment). On leaves of plants from the control treatment, uredia produced many urediniospores at 9 days after inoculation, and the ASR severity was 15, 8 and 9%, respectively, for plants from control, PS and CS treatments. In conclusion, the spray of PS contributed to reduce the number of uredia per cm² of leaf area and both PS spray and CS resulted in lower ASR symptoms.

A brusone, causada por Pyricularia oryzae, é a doença fúngica mais importante do arroz no mundo. O objetivo deste estudo foi comparar o suprimento radicular e foliar de silício solúvel (Si) na resistência do arroz à brusone. A aplicação de Si solúvel para as raízes das plantas de arroz aumentou a concentração de Si nos tecidos foliares quando comparados aos de plantas cultivadas em solo suprido com silicato de cálcio. Não houve aumento na concentração foliar de Si após a aplicação de Si solúvel, independentemente de as folhas terem sido lavadas ou não antes da análise. Foi demonstrado por microanálise de raios-X que a deposição de Si foi muito semelhante na epiderme de plantas pulverizadas com Si solúvel, com raiz supridas com Si solúvel ou cultivadas em solo com silicato de cálcio. O tamanho da lesão, o número de lesões por cm² de folha e a área abaixo da curva de progresso da brusone foram reduzidos em plantas cultivadas em solos que receberam a aplicação de Si solúvel ou foram supridas com silicato de cálcio. Os resultados deste estudo demonstram que o fornecimento de Si solúvel às raízes ou a sua pulverização sobre as folhas de arroz podem diminuir os sintomas da brusone.

Blast, caused by Pyricularia oryzae, is the most important fungal disease of rice worldwide. This study aimed to compare root and foliar supply of soluble silicon (Si) on rice resistance to blast. The application of soluble Si to the roots increased Si concentration in leaf tissues as compare to plants grown in soil amended with calcium silicate. There was no increase in leaf Si concentration after soluble Si spray, regardless if the leaves were washed or not before analysis. X-ray microanalysis revealed that Si deposition was very similar on the leaf epidermis of plants sprayed with soluble Si, root amended with soluble Si or grown in soil amended with calcium silicate. The lesion size, the number of lesions per cm² of leaf and the area under blast progress curve were reduced for rice plants grown in soil that received the application of soluble Si or was amended with calcium silicate. The results of this study showed that the supply of soluble Si to the roots or its spray onto to the rice leaves can decrease blast symptoms.

O objetivo deste trabalho foi avaliar o efeito do silício (Si) no processo infeccioso de Phakopsora pachyrhizi em folíolos de soja cultivada em solução nutritiva com ou sem Si. Observações realizadas sob microscópio de luz e microscópio eletrônico de varredura indicaram que, nos folíolos das plantas supridas com Si, as urédias foram menores e em menor número. Houve redução de 27, 23 e 60% no número de lesões, urédias fechadas e urédias abertas, respectivamente, nos folíolos das plantas com Si. Plantas de soja supridas com Si apresentam redução nos sintomas da ferrugem-asiática-da-soja.

The objective of this work was to evaluate the effect of silicon (Si) on the infection process of Phakopsora pachyrhizi in leaflets of soybean plants grown in nutrient solution with or without Si. Observations done with light microscope and scanning electron microscope indicated that, in leaflets of plants supplied with Si, uredia were smaller and fewer in number. There were reductions of 27, 23 and 60% in the number of lesions, closed uredia and open uredia, respectively, in leaflets of plants with Si. Soybean plants supplied with Si show reduction in Asian soybean rust symptoms.

This study investigated the experience of professional nurses involved in the care of cancer patients whose cancer was beyond treatment. The study had a qualitative approach and was undertaken with the participation of thirteen professionals from a nursing team in a teaching hospital in the countryside in Sao Paulo state. The data was collected through interviews between August and October 2009. By applying Bardin's content analysis, the data was categorized in three groups; nursing routines with patients with incurable cancer, facing work with patients in the terminal phase, and difficulties in working with patients beyond cure. The results indicated that patient care was limited to physical care, and that facing work with these patients was accomplished with individual strategies, putting patient safety at risk. The health care professionals' lack of preparedness for emotional care was the main difficulty related, with evidence for the need for training in this matter.

Esta investigación analizó la experiencia del profesional de enfermería en el cuidado al paciente oncológico sin posibilidad de cura. Se trata de un estudio de abordaje cualitativo, con participación de 13 profesionales del equipo de enfermería de un hospital de enseñanza del interior paulista. Los datos fueron recogidos entre agosto y octubre/2009, por medio de entrevista. El análisis de contenido de Bardin posibilitó la categorización de los datos en: El cotidiano de la enfermería con el paciente oncológico sin posibilidad de cura; El afrontamiento del trabajo con paciente en fase terminal; y Dificultades en el trabajo con el paciente sin posibilidad de cura. Los resultados apuntaron que la asistencia a los pacientes se restringió a los cuidados físicos y el afrontamiento se dió con estrategias individuales, siendo posible poner en riesgo la seguridad del paciente. La falta de preparación de los profesionales para el cuidado emocional fue la principal dificultad relatada, con evidencias de necesidad de su capacitación.

Esta pesquisa investigou a experiência do profissional da enfermagem no cuidado ao paciente oncológico fora de possibilidade de cura; trata-se de um estudo de abordagem qualitativa, com participação de 13 profissionais da equipe de enfermagem de um hospital de ensino do interior paulista. Os dados foram coletados entre agosto e outubro/2009, por meio de entrevista. A análise de conteúdo de Bardin possibilitou a categorização dos dados em: O cotidiano da enfermagem com o paciente oncológico fora de possibilidade de cura; O enfrentamento do trabalho com paciente em fase terminal e Dificuldades no trabalho com o paciente fora de possibilidade de cura. Os resultados apontaram que a assistência aos pacientes restringiu-se aos cuidados físicos e o enfrentamento se deu com estratégias individuais, podendo colocar em risco a segurança do paciente. O despreparo dos profissionais para o cuidado emocional foi a principal dificuldade relatada, com evidências de necessidade de sua capacitação.

Este trabalho objetivou avaliar o potencial do ácido jasmônico (AJ), quitosana desacetilada (QUI), silicato de potássio (SP), acibenzolar-S-metil (ASM), Ethefon (ET) e fosfito de potássio (FP) na redução da severidade da brusone do trigo. O fungicida tebuconazole (TE) e a água destilada (AD) foram utilizados como tratamentos controle. Plantas das cultivares BR 23, BH 1146 e BRS 208 foram pulverizadas com AJ, QUI, SP, ASM, ET, FP, TE e AD 24 h antes da inoculação com Pyricularia grisea. Avaliou-se o período de incubação (PI), a severidade e o efeito fungitóxico dos produtos no crescimento micelial de P. grisea. Para o PI, não houve diferença significativa entre os fatores cultivares e tratamentos, mas para a severidade houve interação entre esses fatores. A menor severidade da brusone para a cultivar BR 23 ocorreu com a pulverização do TE, FP e ET, os quais não diferiram estatisticamente. Para BH 1146, os tratamentos AD, QUI e ASM não diferiram estatisticamente, mas diferiram dos demais tratamentos que apresentaram menor severidade. A aplicação do TE e do FP garantiram uma menor severidade da brusone para a cultivar BRS 208. O FP propiciou uma maior redução da severidade da brusone nos dois cultivares. Os menores valores para o crescimento micelial de P. grisea ocorreram com a adição de TE e SP no meio de cultura. Os resultados desse estudo apontam para o efeito promissor do FP e do ET na potencialização da resistência do trigo à brusone, a qual mostrou ser dependente do nível de resistência basal da cultivar de trigo.

This study aimed to determine the potencial of jasmonic acid (JA), deacetylated chitosan (DC), potassium silicate (PS), Acibenzolar-S-Methyl (ASM), ethephon (ET), and potassium phosphate (PP) on the reduction of blast severity on wheat. The fungicide tebuconazole (TE) and distilled water (DA) were used as control treatments. Plants from the cultivars BR 23, BH 1146, and BRS 208 were sprayed with JA, DC, PS, ASM, ET, PP, TE, and DA 24 h before inoculation with Pyricularia grisea. The incubation period (IP), blast severity, and the effect of the treatments on mycelial growth of P. grisea were evaluated. For the IP, there was no significant difference among cultivars and also for the treatments, but there was interaction between these factors for severity. The lowest severity for BR 23 cultivar occurred with the spray of TE, PP, and ET, which were not significantly different among them. For BH 1146 cultivar, the treatments DA, DC, and ASM were not significantly different among them, but differed significantly from the other treatments to which were obtained the lowest severity. The spray of TE and PP gave the best reduction on severity for BRS 208 cultivar. The PP was the treatment that most reduced severity on the three cultivars tested. The lowest values for mycelial growth of P. grisea occurred upon the addition of TE and PS to the culture medium. The results of this study point to the promising effect of PP and ET in the potentiation of wheat resistance to blast disease, which showed to be dependent on the basal level of resistance of the cultivar.

O objetivo deste trabalho foi avaliar o progresso da ferrugem asiática (Phakopsora pachyrhizi) em genótipos de soja destinados à produção de silagem, sob condições naturais de infecção. Avaliou-se a severidade da ferrugem ao longo do tempo e a capacidade combinatória de cinco cultivares e 20 progênies F3 de soja. A maior área abaixo da curva de progresso da ferrugem (AACPF) foi de 2.116, para as progênies originadas do cruzamento entre as cultivares UFVS 2003 x UFV16, e a menor de 1.307, para UFV16 x Tucunaré. Houve efeito significativo das capacidades geral e específica de combinação, para a AACPF entre os genitores e as progênies, bem como para os cruzamentos recíprocos. Esses resultados indicam que a resistência à ferrugem asiática da soja pode ser influenciada por componentes maternos.

The objective of this work was to evaluate the progress of Asian soybean rust (Phakopsora pachyrhizi) on Brazilian soybean genotypes destined for silage production, under natural conditions of infection. Rust severity over time and combining ability of five cultivars and 20 F3 soybean progenies were evaluated. The largest area under rust progress curve (AURPC) was 2,116 for progenies from the cross between cultivars UFVS 2003 x UFV16, and the smallest was 1,307 for UFV16 x Tucunaré. The effects of the general and specific combining abilities for AURPC were significant between the parents and progenies, as well as for the reciprocal crosses. These results indicate that resistance to Asian soybean rust can be influenced by maternal components.