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au:"Ludwig, H."

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PHYTOTOXIC CONSTITUENTS FROM ENDOPHYTIC FUNGUS Xylaria cubensis ASSOCIATED WITH Eugenia brasiliensis
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Biasetto, Carolina R.

; Somensi, Andressa

; Abdalla, Viviane de C. P.

; Abreu, Lucas M. de

; Gualtieri, Sonia C. J.

; Pfenning, Ludwig H.

; Bolzani, Vanderlan da S.

; Araujo, Angela R.

Química Nova

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may 2019, Volume 42 N. 5 Pages 485 - 488

Abstract: En | Text: En | PDF: En

The upscaling of Xylaria cubensis, an endophyte of Eugenia brasiliensis (Myrtaceae), in PDB medium led to the isolation of known compounds including cytochalasin D (7) and cytochalasin C (8), which exhibited relatively higher phytotoxic activity in all the concentrations tested compared to the commercial herbicide GOAL®. Besides the aforementioned metabolites, one diketopiperazine (DKP) and two isocoumarins were isolated and two DKPs were also identified in the mixture. The structures were determined by 1D and 2D 1H NMR, MS analyses and were compared with the literature.

https://doi.org/10.21577/0100-4042.20170367 652 downloads

Griseofulvin, Diketopiperazines and Cytochalasins from Endophytic Fungi Colletotrichum crassipes and Xylaria sp., and Their Antifungal, Antioxidant and Anticholinesterase Activities
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Chapla, Vanessa M.

; Zeraik, Maria L.

; Cafeu, Mariana C.

; Silva, Geraldo H.

; Cavalheiro, Alberto J.

; Bolzani, Vanderlan S.

; Young, Maria C. M.

; Pfenning, Ludwig H.

; Araujo, Angela R.

Journal of the Brazilian Chemical Society

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aug 2018, Volume 29 N. 8 Pages 1707 - 1713

Abstract: En | Text: En | PDF: En

One new natural product, 1-phenylethyl-O-a-L-rhamnopyranoside, together with eight known diketopiperazines and two benzene derivatives were isolated from the endophytic fungus Colletotrichum crassipes, whereas six known compounds including two griseofulvins, three cytochalasins and one dihydroisocoumarin were produced from the endophyte Xylaria sp., both endophytic fungi are associated with leaves of Casearia sylvestris. Cyclo(D)-Pro-(D)-Phe, N-(2-phenylethyl)acetamide and 5-carboxy-6-hydroxy-3-methyl-3,4-dihydroisocoumarin exhibited potent antifungal activity against Cladosporium cladosporioides and C. sphaerospermum. The compounds cyclo(D)-Pro-(D)-Phe, griseofulvin, cytochalasin B and cytochalasin D exhibited antioxidant activity, and the compounds cyclo(D)-Pro-(D)-Phe, cytochalasin B and cytochalasin C showed potent acetylcholinesterase (AChE) inhibition. In addition, this is the first report on the isolation of secondary metabolites from two endophytic fungal strains, associated with Casearia sylvestris.

https://doi.org/10.21577/0103-5053.20180045 781 downloads

Diversity of Brazilian Fungi
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Maia, Leonor C.

; Carvalho Júnior, Aníbal A. de

; Cavalcanti, Laise de H.

; Gugliotta, Adriana de M.

; Drechsler-Santos, Elisandro R.

; Santiago, André L.M. de A.

; Cáceres, Marcela E. da S.

; Gibertoni, Tatiana B.

; Aptroot, André

; Giachini, Admir J.

; Soares, Adriene M. da S.

; Silva, Allyne C.G.

; Magnago, Altielys C.

; Goto, Bruno T.

; Lira, Carla R.S. de

; Montoya, Carlos A.S.

; Pires-Zottarelli, Carmen L.A.

; Silva, Danielle K.A. da

; Soares, Dartanhã J.

; Rezende, Diogo H.C.

; Luz, Edna D.M.N.

; Gumboski, Emerson L.

; Wartchow, Felipe

; Karstedt, Fernanda

; Freire, Fernando M.

; Coutinho, Flávia P.

; Melo, Georgea S. N. de

; Sotão, Helen M. P.

; Baseia, Iuri G.

; Pereira, Jadergudson

; Oliveira, Jadson J.S. de

; Souza, João F.

; Bezerra, José L.

; Neta, Lídia S. Araujo

; Pfenning, Ludwig H.

; Gusmão, Luís F.P.

; Neves, Maria A.

; Capelari, Marina

; Jaeger, Melissa C.W.

; Pulgarín, Melissa P.

; Menolli Junior, Nelson

; Medeiros, Priscila S. de

; Friedrich, Raquel C.S.

; Chikowski, Renata dos S.

; Pires, Ricardo M.

; Melo, Roger F.

; Silveira, Rosa M.B. da

; Urrea-Valencia, Salomé

; Cortez, Vagner G.

; Silva, Valéria F. da

Rodriguésia

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2015, Volume 66 N. 4 Pages 1033 - 1045

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Resumo Até 2010, o conhecimento sobre a diversidade de fungos do Brasil estava registrado em publicações esparsas de taxonomia e ecologia e em algumas poucas listas de espécies. Com a publicação do Catálogo de Plantas e Fungos do Brasil, e a disponibilização da lista online, tem sido possível agregar o conhecimento disperso. A versão ora apresentada acrescenta 2.111 nomes de espécies aos 3.608 listados em 2010. São citadas 5.719 espécies de fungos distribuídas em 1.246 gêneros, 102 ordens e 13 divisões, consistindo em considerável aumento em relação a 2010, quando estavam registrados 924 gêneros e 78 ordens. Predominam os Basidiomycota (2.741 espécies, em 22 ordens) e Ascomycota (1.881 espécies, em 41 ordens). A Mata Atlântica possui a maior quantidade de registros, com 3.017 espécies, seguido pela Amazonia (1.050), Caatinga (999), Cerrado (638) e Pampa e Pantanal com 84 e 35 espécies, respectivamente. A região Nordeste tem a maior riqueza (2.617 especies), seguida pelo Sudeste (2.252), Sul (1.995), Norte (1.301) e Centro Oeste (488 espécies). Em relação aos Estados da Federação, São Paulo (1.846 espécies), Pernambuco (1.611) e Rio Grande do Sul (1.377) são os mais diversos.

Abstract Knowledge about the Brazilian fungal diversity was, until 2010, recorded in few taxonomy and ecology publications, as well as in a handful of species lists. With the publication of the Catálogo de Plantas e Fungos do Brasil and the continued availability of an online list, it has been possible to aggregate this dispersed knowledge. The version presented here adds 2,111 species names to the 3,608 listed in 2010. A total of 5,719 species of fungi distributed in 1,246 genera, 102 orders and 13 phyla represents a considerable increase over the last five years, when only 924 genera and 78 orders were registered. Basidiomycota (2,741 species in 22 orders) and Ascomycota (1,881 species in 41 orders) predominate over other groups. The Atlantic Rainforest has the largest number of records, with 3,017 species, followed by Amazon Rainforest (1,050), Caatinga (999), Cerrado (638) and Pampa and Pantanal with 84 and 35 species, respectively. The Northeast region has the greatest richness (2,617 species), followed by Southeast (2,252), South (1,995), North (1,301) and Central-West (488 species). Regarding the States of the Federation, São Paulo with 1,846 species, Pernambuco with 1,611 and Rio Grande do Sul with 1,377 species are the most diverse.

https://doi.org/10.1590/2175-7860201566407 9322 downloads

The etiological agent of cotton ramulosis represents a single phylogenetic lineage within the Colletotrichum gloeosporioides species complex
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Salustiano, Maria Eloisa

; Rondon, Marina Nunes

; Abreu, Lucas M.

; Costa, Sarah da Silva

; Machado, José da Cruz

; Pfenning, Ludwig H.

Tropical Plant Pathology

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oct 2014, Volume 39 N. 5 Pages 357 - 367

Abstract: En | Text: En | PDF: En

Ramulosis of cotton, caused by Colletotrichum gossypii var. cephalosporioides (CGC), is an important disease of cotton in Brazil. The main objective of this work was to test whether CGC is a phylogenetic species inside the Colletotrichum gloeosporioides species complex. A Bayesian inference phylogenetic analysis of a combined ITS and TUB2 dataset was conducted with 21 strains identified as CGC and five strains of Colletotrichum gossypii (CG), associated with cotton anthracnose, obtained from diseased plants from different regions of Brazil. All CGC strains formed a highly supported lineage inside the clade of Colletotrichum theobromicola, a member of the C. gloeosporioides species complex. CG strains formed another lineage in the same clade. These findings were supported by a second analysis conducted with three genes (ITS+TUB2+GAPDH) and a subset of five CGC and three CG strains. During pathogenicity tests, all five CGC strains tested induced typical symptoms of ramulosis on inoculated plants, including foliar necrosis, death of apical meristems and over sprouting. Plants inoculated with CG strains exhibited foliar necrotic spots two months after inoculation. These results give phylogenetic support for the placement of CGC in the C. gloeosporioides species complex, and the distinction between the ramulosis and anthracnose pathogens of cotton in Brazil.

3360 downloads

First report and characterization of Fusarium circinatum, the causal agent of pitch canker in Brazil
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Pfenning, Ludwig H.

; Costa, Sarah da Silva

; Melo, Maruzanete Pereira de

; Costa, Hélcio

; Ventura, José Aires

; Auer, Celso Garcia

; Santos, Álvaro Figueredo dos

Tropical Plant Pathology

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jun 2014, Volume 39 N. 3 Pages 210 - 216

Abstract: En | Text: En | PDF: En

Pitch canker is one of the most important diseases of pine trees worldwide, including South America. The causal agent of this disease is Fusarium circinatum, a member of the Gibberella fujikuroi complex (GFC). In South America, the species is reported from Colombia, Uruguay and Chile, but is considered a quarantine organism in Brazil. In this study we characterized isolates obtained from symptomatic pine seedlings intercepted in a nursery in Santa Catarina State using phylogenetic analyses, crossings and morphological markers. The Brazilian isolates grouped with reference material in an unique clade and formed fertile perithecia when crossed with reference tester strains. The detailed characterization given here and the availability of tester strains will allow for reliable identification and support monitoring of this important plant pathogen.

4440 downloads

Impact of Amazon land use on the community of soil fungi
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Fracetto, Giselle G. M.

; Azevedo, Lucas C.B.

; Fracetto, Felipe J. C.

; Andreote, Fernando D.

; Lambais, Marcio R.

; Pfenning, Ludwig H.

Scientia Agricola

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apr 2013, Volume 70 N. 2 Pages 59 - 67

Abstract: En | Text: En | PDF: En

Considered as one of the most biodiverse biomes, the Amazon has a featured role in the discovery of new species of plants, animals and microorganisms, which may be important for the functionality of different ecosystems. However, studies on the impacts resulted from changes in the Amazon land use on microbial communities and their functions are still limited. In this context, the soil fungal diversity can act as an important indicator of environmental stress caused by land use of the Amazon. This study describes changes in soil fungal communities caused by different systems of land use (primary forest, secondary forest, agroforestry, agriculture and pasture). Communities were observed in each of the areas using denaturing gradient gel electrophoresis (DGGE) of 18S rRNA gene combined with the non-metric multidimensional scaling (NMDS). Unique bands indicated the dominance of particular fungal groups in each of the specific treatments, mainly in areas converted to pasture, which differed greatly from samples of other systems of land use (SLU). The analysis of partial sequence of the 18S rRNA gene of fungi in soils under primary forest, agriculture and pasture showed differences (p = 0.001), evidencing the fungal community response to such changes. Most abundant phyla were the Zygomycota in the soil under primary forest and agricultural land, and Basidiomycota in the soil under pasture. The results show that the Amazon soil is an ecosystem susceptible to environmental changes in regarding the fungi community inhabiting this niche.

4301 downloads

Relação nitrogênio/potássio com mancha de Phoma e nutrição de mudas de cafeeiro em solução nutritiva
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Lima, Luciana M. de

; Pozza, Edson A

; Torres, Henrique N

; Pozza, Adélia A.A

; Salgado, Mirian

; Pfenning, Ludwig H

Tropical Plant Pathology

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aug 2010, Volume 35 N. 4 Pages 223 - 228

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Este trabalho foi realizado com os objetivos de avaliar a influência de diferentes doses de nitrogênio (N) e de potássio (K), fornecidos via solução nutritiva, na intensidade da mancha de Phoma e determinar a quantidade de matéria seca e a concentração de macro e micronutrientes em folhas e ramos de mudas do cafeeiro. Os tratamentos consistiram em 5 doses de K (4, 5, 6, 7 e 8 mmol/L) combinadas com 5 doses de N (3, 7, 11, 15 e 19 mmol/L) em esquema fatorial, constituindo 25 tratamentos, com 3 repetições. Esse experimento foi repetido três vezes a 20ºC. Com o aumento das doses de N, houve aumento linear em 34,8%, para AACPI (Área abaixo da curva de progresso da incidência) e 34,3%, para AACPS (Área abaixo da curva de progresso da severidade). Aumentando as doses de K, verificou-se redução de forma quadrática, tanto para AACPI quanto para AACPS até a dose de 7 mmol/L, a partir da qual ocorreu aumento da doença. A matéria seca das mudas de café aumentou linearmente com o aumento das doses de N. Com o aumento das doses de N, observou-se aumento de N na parte aérea. As doses de potássio influenciaram significativamente os teores de N, K, Ca, S e B nas folhas e ramos. Assim, a nutrição balanceada, além de minimizar alterações nutricionais, pode ser manipulada para reduzir o número de pulverizações com fungicidas neste patossistema.

This work was carried out to evaluate different dosages of N and K amended through roots via nutrient solution on the intensity of Phoma spot in coffee seedlings, and to determine the dry matter and the concentration of macro and micronutrients in the aerial part of coffee seedlings inoculated with Phoma tarda. Treatments encompassed 5 dosages of K (4, 5, 6, 7 and 8 mmol/L) combined to 5 dosages of N (3, 7, 11, 15 and 19 mmol/L), in 25 treatments and three replicates. This assay was repeated three times at 20ºC. By increasing the amended N, there was a linear increase of 34.8% for AUIPC (Area under incidence progress curve) and 34.3% for AUSPC (Area under severity progress curve). By increasing the K, there was a square-shaped reduction for both AUIPC and AUSPC. The dry matter of coffee seedlings increased linearly with the increase in the amended N. By increasing the amended N, a corresponding increase in shoot N content was observed. Dosages of potassium significantly influenced the N, K, Ca, S and B contents in the shoot of coffee seedlings. Thus, balanced fertilization, besides minimizing nutritional problems, can be manipulated to reduce the number of fungicide applications in this pathosystem.

4054 downloads

Citocalasinas produzidas por Xylaria sp., um fungo endofítico de Piper aduncum (piperaceae)
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Silva, Geraldo H.

; Oliveira, Camila M. de

; Teles, Helder L.

; Bolzani, Vanderlan da S.

; Araujo, Angela R.

; Pfenning, Ludwig H.

; Young, Maria Claudia M.

; Costa-Neto, Claudio M.

; Haddad, Renato

; Eberlin, Marcos N.

Química Nova

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2010, Volume 33 N. 10 Pages 2038 - 2041

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

A chemical study on the EtOAc extract produced by Xylaria sp., an endophytic fungus from Piper aduncum, resulted in the isolation of a new cytochalasin 1, along with five known 19,20-epoxycytochalasin D (2), C (3), N (4), Q (5), and R (6). The 1-6 were evaluated against the fungi C. cladosporioides and C. sphaerospermum and only 5 showed weak activity. The cytotoxicity in vitro against HeLA and CHO cells lines were investigated and the cytochalasins 2-4, and 6 showed a strong activity against HeLA. The DNAdamaging activity of 1-6 were also investigated against mutant strains of S. cerevisiae.

4123 downloads

Escala diagramática para avaliação da severidade da mancha de Phoma do cafeeiro
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Salgado, Mirian

; Pozza, Edson A.

; Lima, Luciana Maria de

; Pereira, Ricardo T.G.

; Pfenning, Ludwig H.

Tropical Plant Pathology

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dec 2009, Volume 34 N. 6 Pages 422 - 427

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

Para avaliar a severidade da mancha de Phoma do cafeeiro (Phoma tarda) foi construída uma escala diagramática com oito níveis de severidade. A escala foi então validada por sete avaliadores. Quanto à precisão da escala, os valores de R² variaram de 0,82 até 0,87 e de 0,85 até 0,94 sem e com o uso da escala, respectivamente. Os erros absolutos médios, severidade real menos a estimada, foram na maioria inferiores a 10%. A escala apresentou boa acurácia com valores estimados de severidade próximos dos valores de severidade real. A reprodutibilidade dos valores estimados por avaliadores foi satisfatória, com valores de R² superiores a 0,75 em todos os casos. A escala construída e validada pode ser considerada uma boa ferramenta para avaliar a severidade da mancha de Phoma, uma das mais importantes doenças do cafeeiro.

With the aim of offering an aid to evaluate disease severity of phoma leaf blight of coffee trees, a diagrammatic scale with eight levels of severity was developed. The scale was then validated by seven independent testers. As to the precision of the scale, R² values varied between 0.82 and 0.87, and 0.85 and 0.94, with and without the use of the scale, respectively. The absolute average error, expressing the real severity minus the estimated severity , was mostly lower than 10%. The scale evidenced good accuracy, with estimated values of severity close to the values of real severity. Reproducibility of the estimated values by the raters was satisfactory, with R² values superior to 0.75 in all cases. This validated scale is a suitable tool for the evaluation of the severity of Phoma leaf blight, one of the most important diseases of the coffee tree.

4705 downloads Cited 5 times in SciELO

10.

Novel antimicrobial secondary metabolites from a Penicillium sp. isolated from Brazilian cerrado soil
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Petit, Philippe

; Lucas, Esther M. F.

; Abreu, Lucas M

; Pfenning, Ludwig H

; Takahashi, Jacqueline A

Electronic Journal of Biotechnology

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oct 2009, Volume 12 N. 4 Pages 8 - 9

Abstract: En | Text: En | PDF: En

The morphological features of a Penicillium, isolated from Brazilian cerrado soil, were characterized and showed to be distinctly different from all well-defined Penicillium species. Chemical and biological investigation on the ethyl acetate extract of this Penicillium isolate resulted in the isolation of three new naphthalenoids: a major metabolite, methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate and two minor ones, methyl 6-acetyl-4-methoxy-7,8-dihydroxynaphthalene-2-carboxylate and methyl 6-acetyl-4-methoxy-5,8-dihydroxynaphthalene-2-carboxylate. Their structures were determined based on their mono and bidimensional nuclear magnetic resonance data. Acetyl, allyl and methoxyl derivatives of the major metabolite were prepared in order to establish structure-activity relation. Antimicrobial activity of the major natural product and its semi-synthetic derivatives was screened by macro dilution methodology and the corresponding minimum inhibitory concentrations were determined. Natural secondary metabolite methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate, isolated in a very high yield (0.3175 mg.L-1) showed to be the most active compound, possessing expressive activity against Candida albicans (minimum inhibitory concentration (MIC) 32 µg/mL), Listeria monocitogenes and Bacillus cereus (MIC 64 µg/mL for both).

5128 downloads Cited 1 time in SciELO

11.

Fitopatologia Brasileira goes international
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Pfenning, Ludwig H.

; Resende, Mário Lúcio V.

; Casela, Carlos R.

Tropical Plant Pathology

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feb 2008, Volume 33 N. 1 Pages 3 - 3

Abstract: En | Text: En | PDF: En

2089 downloads

12.

Métodos de inoculação e efeitos de Fusarium oxysporum f. sp. vasinfectum em sementes de algodoeiro
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Sousa, Marcella V.

; Machado, José C.

; Pfenning, Ludwig H.

; Kawasaki, Vivian H.

; Araújo, Dejânia V.

; Silva, Adriano A.

; Martini Neto, Alfredo

Tropical Plant Pathology

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feb 2008, Volume 33 N. 1 Pages 41 - 48

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

A disponibilidade de sementes com diferentes níveis de infecção por fungos, transmissíveis por esta via, é importante na realização de diversos estudos. Este trabalho teve como objetivo avaliar procedimentos de inoculação e períodos de exposição das sementes de algodoeiro ao Fusarium oxysporum f. sp. vasinfectum (Fov), por meio da técnica de restrição hídrica, capazes de proporcionar elevados índices de infecção. Para isso, foram comparados os métodos: 1) imersão das sementes por 10 min em suspensão de conídios (10(6) conídios/mL) com incubação, em seguida, em substrato com potencial osmótico de -1,0 MPa; 2) atomização de suspensão de conídios (10(6) conídios/mL) sobre o substrato e sobre as sementes, e 3) contato direto das sementes com o micélio do fungo previamente desenvolvido no substrato de papel. Todos os métodos permitiram a obtenção de sementes com diferentes potenciais de inóculo, equivalentes aos diferentes tempos de exposição, 24 h, 48 h, 72 h, 96 h e 120 h, ao substrato contendo ou não o fungo previamente desenvolvido. As avaliações neste ensaio foram feitas por meio dos testes de germinação em rolo de papel, emergência em solo/areia e sanidade. O método mais eficaz foi o de imersão das sementes na suspensão de conídios com incubação em substrato de papel com restrição hídrica. O período de tempo que as sementes devem ficar em contato com o patógeno, sem afetar a sua qualidade fisiológica, é de 53 h a 57 h.

The availability of seeds infected by fungi or other pathogens transmissible by this way is important for several purposes. This work was conducted to evaluate proceedings of inoculations and period of exposition of seeds to Fusarium oxysporum f. sp. vasinfectum through the water restriction technique. The following methods were compared: (1) seed immersion in a conidial suspension (10(6) conidia/mL) following incubation in substrate with an osmotic potential of -1.0 MPa; (2) atomization of a conidial suspension (10(6) conidia/mL) upon the substrate and on the seeds, and (3) direct contact of the seeds with the fungus mycelium, grown upon the substrate. All methods enabled to obtain seeds with different inoculum potential equivalent to different times, 24, 48, 72, 96 and 120 hours of seed expositions to the fungus. To evaluate the efficacy of infection, germination tests on roll paper and in soil/sand substrate and Blotter Test were applied. The most effective method was the immersion of seeds in inoculum suspension followed incubation in substrate with water restriction. The period of time that seeds should stay in contact with the pathogen, without affecting their physiological quality, was 53 h to 57 h.

3907 downloads

13.

Colletotrichum coccodes, patógeno de solanáceas no Brasil
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Costa, Maria Helena D.

; Pfenning, Ludwig H.

; Pozza, Edson A.

Fitopatologia Brasileira

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jun 2006, Volume 31 N. 3 Pages 315 - 315

Abstract: Pt | Text: Pt | PDF: Pt

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14.

Peronosclerospora sorghi, o agente etiológico do míldio do sorgo
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Barbosa, Flávia C. Rufini

; Pfenning, Ludwig H.

; Casela, Carlos R.

Fitopatologia Brasileira

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apr 2006, Volume 31 N. 2 Pages 119 - 132

Abstract: Pt En | Text: Pt En | PDF: Pt | PDF: En

O agente etiológico do míldio do sorgo, Peronosclerospora sorghi, infecta as culturas do sorgo (Sorghum spp.) e do milho (Zea mays). Esse patógeno encontra-se disseminado em muitas regiões tropicais e subtropicais do mundo e pode ocasionar danos significativos na produção de sorgo quando as condições climáticas são favoráveis à sua ocorrência e em cultivares de alta susceptibilidade. No Brasil, antes restrito aos estados da região Sul, o míldio foi registrado também nos estados da região Sudeste e Centro-Oeste, causando prejuízos principalmente em áreas de produção de sementes. O cultivo de genótipos resistentes é o método mais eficiente para o controle da doença. Entretanto, essa estratégia é dificultada pela alta variabilidade genética apresentada pelo patógeno. Essa revisão aborda aspectos da taxonomia, biologia e distribuição geográfica do míldio do sorgo e discute questões relacionadas com a sua epidemiologia e controle, enfatizando estratégias que utilizam resistência genética.

The causal agent of sorghum downy mildew, Peronosclerospora sorghi, is a pathogen of sorghum species (Sorghum spp.) and corn (Zea mays). The pathogen is disseminated in many tropical and subtropical regions all around the world, causing considerable losses when conditions are favorable for its development or susceptible cultivars are used. Within Brazil it was initially restricted to the Southern region but has now also spread to the Southeast and Middle-West, causing significant losses specifically in areas of seed production. The use of resistant genotypes is the most efficient method to control the disease. Nevertheless, a high genetic variability of the pathogen makes it difficult to use resistant cultivars. This revision considers aspects of taxonomy and biology of sorghum downy mildew and discusses questions related to geographic distribution, epidemiology and control, focusing on strategies that use genetic resistance.

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15.

Ocorrência natural de Greeneria uvicola em uva
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Pfenning, Ludwig H.

; Goussain, Rita de Cássia S.

; Almeida, Anderson R.

; Alves, Eduardo

Fitopatologia Brasileira

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apr 2006, Volume 31 N. 2 Pages 213 - 213

Abstract: Pt | Text: Pt | PDF: Pt

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