The genus Pythium Pringsheim from Brazilian cerrado areas, in the state of São Paulo, Brazil

Baptista, Filipe R; Pires-Zottarelli, Carmen Lidia Amorim; Rocha, Maristela da; Milanez, Adauto Ivo

doi:10.1590/s0100-84042004000200008

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…As características dos espécimes concordam com a descrição de Plaats-Niterink (1981) e Baptista et al (2004); no entanto, Dick (1989) As características dos espécimes estão de acordo com a descrição de Frezzi (1956), Plaats-Niterink (1981) e Baptista et al (2004). As estruturas sexuadas são menores que as citadas por Pires- , que descrevem oogônios esféricos com 18-26 µm diâm.…”

Section: Resultsunclassified

Oomycota (Straminipila) da Reserva Biológica de Paranapiacaba, Santo André, SP, Brasil

Gomes

Pires-Zottarelli

2008

Acta Bot. Bras.

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Durante o período de novembro/2003 a novembro/2004, coletas trimestrais de amostras de água e solo foram realizadas na Reserva Biológica de Paranapiacaba, importante fragmento de Mata Atlântica localizado no estado de São Paulo, para estudo da diversidade de oomicetos. Para o isolamento destes organismos, as amostras foram tratadas pelo método de iscagem, que resultou na identificação de 35 espécies, das quais uma pertence a Leptomitales, quatro a Peronosporales, duas a Rhipidiales, e 28 a Saprolegniales, sendo descritas, comentadas e ilustradas neste trabalho as de ocorrência relatada no Brasil, das quais três são citadas pela primeira vez para o estado de São Paulo, Leptolegnia eccentrica Coker & Matthews, Pythiopsis humphreyana Coker e Pythiopsis irregularis Seymour, e 20 para a Reserva.

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Section: Resultsunclassified

Oomycota (Straminipila) da Reserva Biológica de Paranapiacaba, Santo André, SP, Brasil

Gomes

Pires-Zottarelli

2008

Acta Bot. Bras.

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“…Although extant Peronosporomycetes oogonia bear ornamentation, none appears to have complex branched crowns on the sculptural elements, a character which is used to distinguish the new order. Some modern Pythium oogonia have robust spinose ornamentation [64], [65], especially those of P. oligandrum [66], [67], and P. prolatum Hendrix and Campbell [68], but the extant forms typically lack forked apices on the spines. Other extant forms that exhibit broadly similar robust spinose/conate ornamentation include Aphanomyces stellatus [69], [70], [71].…”

Section: Discussionmentioning

confidence: 99%

Peronosporomycetes (Oomycota) from a Middle Permian Permineralised Peat within the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica

2013

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The fossil record of Peronosporomycetes (water moulds) is rather sparse, though their distinctive ornamentation means they are probably better reported than some true fungal groups. Here we describe a rare Palaeozoic occurrence of this group from a Guadalupian (Middle Permian) silicified peat deposit in the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica. Specimens are numerous and comprise two morphologically distinct kinds of ornamented oogonia, of which some are attached to hyphae by a septum. Combresomyces caespitosus sp. nov. consists of spherical oogonia bearing densely spaced, long, hollow, slender, conical papillae with multiple sharply pointed, strongly divergent, apical branches that commonly form a pseudoreticulate pattern under optical microscopy. The oogonia are attached to a parental hypha by a short truncated stalk with a single septum. Combresomyces rarus sp. nov. consists of spherical oogonia bearing widely spaced, hollow, broad, conical papillae that terminate in a single bifurcation producing a pair of acutely divergent sharply pointed branches. The oogonium bears a short truncate extension where it attaches to the parental hypha. We propose that similarities in oogonium shape, size, spine morphology and hyphal attachment between the Permian forms from the Prince Charles Mountains and other reported Peronosporomycetes from Devonian to Triassic strata at widely separated localities elsewhere in the world delimit an extinct but once cosmopolitan Palaeozoic to early Mesozoic branch of the peronosporomycete clade. We name this order Combresomycetales and note that it played an important role in late Palaeozoic and early Mesozoic peatland ecosystems worldwide.

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“…P. tardiscrescens was originally isolated from diseased wheat roots in Canada. It was later recorded on grass in England and the USA (Van der Plaats-Niterink 1981), and in Brazil in 2004 (Baptista et al 2004). P. tradiscrescens presents aplerotic oospores while in P. graminicola the oospores are plerotic; also, the daily growth rate is slow in P. tradiscrescens.…”

Section: Phylogenetic Analysismentioning

confidence: 99%

Identification and characterization of Pythium graminicola, causal agent of kikuyu yellows in Argentina

Grijalba

Palmucci

Guillín

2017

Trop. plant pathol.

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Kikuyu grass (Pennisetum clandestinum) is a perennial plant that belongs to the Poaceae family. In Argentina, it is used in warm areas as tropical pasture, forage and grass in gardens and sports fields. Species of Pythium have a cosmopolitan distribution and are important pathogens of a wide range of plant hosts. In the spring of 2009, a new disease affected areas cultivated with kikuyu grass in different parks located near the city of Buenos Aires. The symptoms were an evident chlorosis of leaves, which got circular as the affected area expanded, followed by severely rotten roots and blighting. The aim of this study was to identify the causal agent of kikuyu yellows in Argentina. An oomycete was consistently isolated from diseased tissues. The pathogen was identified as Pythium graminicola based on cultural characteristics and the morphology of vegetative and reproductive structures. Phylogenetic analyses were performed based on combined sequence datasets of the internal transcribed spacer of the nuclear rDNA and the beta tubulin gene. Pathogenicity tests were carried out and Koch's postulates were fulfilled. This is the first report of P. graminicola causing kikuyu yellows in Argentina and in the world.

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The genus Pythium Pringsheim from Brazilian cerrado areas, in the state of São Paulo, Brazil

Cited by 7 publications

References 2 publications

Oomycota (Straminipila) da Reserva Biológica de Paranapiacaba, Santo André, SP, Brasil

Oomycota (Straminipila) da Reserva Biológica de Paranapiacaba, Santo André, SP, Brasil

Peronosporomycetes (Oomycota) from a Middle Permian Permineralised Peat within the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica

Identification and characterization of Pythium graminicola, causal agent of kikuyu yellows in Argentina

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