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Susumu Takamatsu - One of the best experts on this subject based on the ideXlab platform.
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podosphaera lini ascomycota erysiphales revisited and reunited with oidium lini
Plant pathology & quarantine online, 2019Co-Authors: Uwe Braun, Preston Chris D, Cook R T A, M. Götz, Susumu TakamatsuAbstract:Podosphaera lini (Erysiphaceae) has recently been detected on linseed, Linum usitatissimum var. crepitans, in England and represents the first unequivocal record of this powdery mildew species from Great Britain. The history of powdery mildew on linseed/flax in the UK is critically discussed. DNA sequence data (ITS + 28S rDNA) have been retrieved, from the British material and a specimen from Germany, to be used for phylogenetic analyses. The position of P. lini as a species of its own in the genus Podosphaera, close to P. macularis (hop powdery mildew), was confirmed in the ITS-based phylogeny. The phylogenetic results, in concordance with the morphological traits of the flax powdery mildew (small peridial cells of the chasmothecia), place this species in Podosphaera sect. Sphaerotheca subsect. Sphaerotheca. Oidium lini, described from Croatia by Skoric in 1926, was later erroneously reduced to a synonymy with Golovinomyces orontii. Oidium lini has been reassessed and is now regarded as a synonym of Podosphaera lini. Oidium lini, cited in the literature as a name published by Bondartsev in 1913, is critically discussed and reviewed. The name O. lini was most likely never validly introduced and is doubtful.
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Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae (Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences - a taxonomic interpretation.
2013Co-Authors: Uwe Braun, Nina Shishkoff, Susumu TakamatsuAbstract:Abstract: Braun, U., Shishkoff, N. & Takamatsu, S. 2001: Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae ( Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences – a taxonomic interpretation. Schlechtendalia 7 : 45-52. Data of a phylogenetic analysis of the Podosphaera ( Sphaerotheca ) fuliginea complex based on rDNA ITS sequences are taxonomically interpreted. Using a morphological species concept, mainly based on the size of the ascomata and the diameter of the thin-walled apical portion of the asci (oculus), combined with biological data, the present taxonomic status of P. balsaminae, P. diclipterae, P. fuliginea, P. intermedia, P. pseudofusca and P. sibirica as separate species has been confirmed. P. fusca emend. as well as P. xanthii emend. are reassessed as complex, compound species. P. euphorbiae-hirtae and P. phaseoli are reduced to synonymy with P. xanthii . Zusammenfassung: Braun, U., Shishkoff, N. & Takamatsu, S. 2001: Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae ( Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences – a taxonomic interpretation. Schlechtendalia 7 : 45-52. Ergebnisse einer phylogenetischen Analyse des Podosphaera ( Sphaerotheca ) fuliginea -Komplexes auf Grundlage von rDNA-ITS-Sequenzen werden taxonomisch ausgewertet. Unter Anwendung eines morphologischen Artkonzepts, hauptsachlich auf Grundlage der Fruchtkorpergrose und des Durchmessers der dunnwandigen Scheitelregion der Asci (Oculus), in Verbindung mit biologischen Daten, wird der gegenwartige taxonomische Status von P. balsaminae, P. diclipterae, P. fuliginea, P. intermedia, P. pseudofusca und P. sibirica bestatigt. P. fusca emend. und P. xanthii emend. werden neu als komplexe Sammelarten bewertet. P. euphorbiae-hirtae und P. phaseoli werden zu P. xanthii gestellt.
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Evolutionary analysis of subsection Magnicellulatae of Podosphaera section Sphaerotheca (Erysiphales) based on the rDNA internal transcribed spacer sequences with special reference to host plants
Canadian Journal of Botany, 2000Co-Authors: Tetsuya Hirata, Nina Shishkoff, James H Cunnington, Urailak Paksiri, Saranya Limkaisang, Banga Grigaliunaite, Yukio Sato, Susumu TakamatsuAbstract:To understand the evolutionary history of subsection Magnicellulatae of Podosphaera section Sphaerotheca, nucleotide sequences of the rDNA internal transcribed spacer region were determined for 79 isolates from 60 host species. With the exception of two species occurring on the Scrophulariaceae, all isolates formed a large, well-defined clade. Genetic diversity among species on the Scrophulariaceae was much larger than the diversity among all other taxa, and the first split of the Magnicellulatae clade was shared by these species. This suggests that the Scrophulariaceae is the earliest host of subsection Magnicellulatae. Isolates from the Asteraceae shared the largest sequence diversity and were represented in all major groups. Most members of the basal groups consisted of isolates from the Asteraceae. This suggests that an early radiation in the large clade occurred on the Asteraceae. Based on the small sequence diversity and placement at the terminal end of the phylogenetic tree of isolates from the Cucurbitaceae and the Fabaceae, it is suggested that the ability of subsection Magnicellulatae to infect these families was acquired more recently. The groupings of fungal taxa by molecular phylogeny showed general agreement with groupings by infectivity, which suggests niche separation caused by host specialization triggers genetic divergence in these fungi.Key words: Ascomycetes, Erysiphaceae, host range, phylogeny, Podosphaera, Sphaerotheca.
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Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera, Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences, some taxonomic consequences
2000Co-Authors: Uwe Braun, Susumu TakamatsuAbstract:Abstract: Braun, U. & Takamatsu, S. 2000: Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera , Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences – some taxonomic consequences. Schlechtendalia 4 : 1-33. The very close relationship between the genera Erysiphe s.str. (= Erysiphe sect. Erysiphe ), Microsphaera , and Uncinula , which are connected by numerous intermediate taxa, is strongly supported by light as well as scanning electron microscopical features and has recently been confirmed by examinations of nucleotide sequences of rDNA internal transcribed spacers (ITS). Erysiphe s.str. and Microsphaera did not group into separate monophyletic lineage, but formed several small mixed clusters. It turned out that the formation of branched ascoma appendages does not have any taxonomic value at generic level. Therefore, Microsphaera is reduced to synonymy with Erysiphe s.str., and the new combinations, which are necessary, are introduced. Uncinula spp. form a basal subclade of the Erysiphe s.str./ Microsphaera ( Pseudoidium ) clade, but since some species of Erysiphe s.str. belong in this subclade, it is necessary to reduce Uncinula to synonymy with the latter genus, too. Erysiphe emend. is formally divided into sections for non-phylogenetical, but morphological groups of species, viz. Erysiphe sect. Erysiphe , E. sect. Microsphaera , and E. sect. Uncinula . Furthermore, examinations of nucleotide sequences of rDNA ITS regions of numerous taxa belonging to tribe Cystotheceae showed that Podosphaera and Sphaerotheca did not form separate monophyletic clades. Taxa of Sphaerotheca sect. Sphaerotheca and sect. Magnicellulatae grouped together with two different sets of Podosphaera spp. in two separate subclades of a single Podosphaera/Sphaerotheca clade. Based on these results and since Podosphaera and Sphaerotheca are morphologically only distinguished by having appendages which are branched and simple, respectively, it is proposed to merge the two genera. New combinations for Sphaerotheca spp. under Podosphaera are introduced. Podosphaera is formally divided into sections and subsections for non-phylogenetical, but morphological groups of species, viz. Podosphaera sec. Podosphaera , P . sect. Sphaerotheca subsect. Sphaerotheca , and subsect. Magnicellulatae . Furthermore, some changes of the classification of the Erysiphaceae are proposed. The following new combinations are introduced: Erysiphaceae tribe Cystotheceae subtribe Sawadaeinae, Erysiphaceae tribe Golovinomyceteae, Erysiphaceae tribe Golovinomyceteae subtribe Arthrocladiellinae and subtribe Neoerysiphinae. Zusammenfassung: Braun, U. & Takamatsu, S. 2000: Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera , and Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences – some taxonomic consequences. Schlechtendalia 4 : 1-33. Die enge Verwandtschaft zwischen den Gattungen Erysiphe s.str. ( = Erysiphe Sektion Erysiphe ), Microsphaera und Uncinula , die durch zahlreiche morphologisch untermediare Taxa verbunden sind, wird stark durch licht- und elektronenmikroskopische Merkmale unterstutzt und durch neue Untersuchungen der Nukleotidsequenzen der rDNA-ITS-Region bestatigt, da diese Gattungen nicht zu verschiedenen monophyletischen Linien gehoren. Erysiphe s.str. und Microsphaera bilden jedoch verschiedene kleine, gemischte Gruppen. Es hat sich herausgestellt, das die Bildung verzweigter Fruchtkorperanhangsel keinen taxonomischen Wert auf Gattungsebene hat. Deshalb wird vorgeschlagen, Microsphaera als Synonym von Erysiphe zu betrachten. Die notwendigen Neukombinationen werden eingefuhrt. Uncinula -Arten bilden ein “Subclade” an der Basis des “ Erysiphe s.str./ Microsphaera ( Pseudoidium )-Clades”. Da auch einige Erysiphe s.str.-Arten in dieses “Subclade” gehoren, ist es notwendig, diese beiden Gattungen zu vereinigen. Erysiphe Sektion Erysiphe, E. Sektion Microsphaera und E. Sektion. Uncinula . Untersuchungen von Nukleotidsequenzen ribosomaler DNA (ITS) zahlreicher Taxa der Cystotheceae zeigten, das Podosphaera und Sphaerotheca keine getrennten “Clades” bilden. Taxa von Sphaerotheca Sektion Sphaerotheca und Sektion Magnicellulatae bilden zusammen mit zwei verschiedenen Gruppen von Podosphaera -Arten getrennte “Subclades”. Auf Grundlage dieser Befunde und da Podosphaera- und Sphaerotheca -Arten morphologisch nur durch verzweigte und einfache Fruchtkorperanhangsel unterschieden sind, wird vorgeschlagen, beide Gattungen zu vereinigen. Neukombinationen von Sphaerotheca -Arten unter Podosphaera werden eingefuhrt. Podosphaera wird formal in folgende morphologisch, aber nicht phylogenetisch begrundete Sektionen und Subsektionen gegliedert: Podosphaera Sektion Podosphaera , P . Sektion Sphaerotheca Subsektion Sphaerotheca , und Subsektion Magnicellulatae . Weiterhin werden einige Anderungen der Klassifizierung der Erysiphaceae vorgeschlagen. Folgende Kombinationen werden eingefuhrt: Erysiphaceae Tribus Cystotheceae Subtribus Sawadaeinae, Erysiphaceae Tribus Golovinomyceteae, Erysiphaceae Tribus Golovinomyceteae Subtribus Arthrocladiellinae und Subtribus Neoerysiphinae.
R T A Cook - One of the best experts on this subject based on the ideXlab platform.
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first record of oidium anamorph of podosphaera xanthii on medusagyne oppositifolia
Plant Pathology, 2010Co-Authors: Timothy Pettitt, B Henricot, D Matatiken, R T A CookAbstract:Powdery mildew first appeared on mature 3-year-old bushes of ‘jellyfish tree’, Medusagyne oppositifolia (Medusagynaceae), grown from seed at Eden Project, Cornwall, England, in collaborative conservation work with the Seychelles Government. Initially, young leaves showed distortion and patches of mycelium bearing conidia. Later, light brown lesions developed and badly affected plants showed extensive leaf-drop, especially destructive in seedlings. This is the first report of powdery mildew on Medusagyne. Conidia are catenate, elliptical to doliiform, (19) 24–34(47AE5) · (13AE5) 15–18 lm with fibrosin bodies and a sinuous wrinkling pattern. Conidiophores erect with a long cylindrical straight or twisted foot-cell, 41–86AE5 (140) · (7) 9–14 (16) lm, arising towards one end of its hyphal mother cell, the lower septum occasionally raised up to 10 lm, followed by a generative cell and 2–5 maturing conidial units. Superficial hyphal cells, 25–105 · 4AE5–11AE5 lm, branched at right angles, bearing inconspicuous or slightly nipple-shaped appressoria. No chasmothecia were present, but characteristics are consistent with Oidium subgenus Fibroidium, the anamorph of Podosphaera. The short, broad germ tubes typical of the fibroidium type, brevitubus subtype narrowed the identification to Podosphaera section Sphaerotheca subsect. Magnicellulatae (Cook & Braun, 2009) with the morphology close to that of Podosphaera (syn. Sphaerotheca) fusca, apparently a ubiquitous species with a broad host range.
Uwe Braun - One of the best experts on this subject based on the ideXlab platform.
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podosphaera lini ascomycota erysiphales revisited and reunited with oidium lini
Plant pathology & quarantine online, 2019Co-Authors: Uwe Braun, Preston Chris D, Cook R T A, M. Götz, Susumu TakamatsuAbstract:Podosphaera lini (Erysiphaceae) has recently been detected on linseed, Linum usitatissimum var. crepitans, in England and represents the first unequivocal record of this powdery mildew species from Great Britain. The history of powdery mildew on linseed/flax in the UK is critically discussed. DNA sequence data (ITS + 28S rDNA) have been retrieved, from the British material and a specimen from Germany, to be used for phylogenetic analyses. The position of P. lini as a species of its own in the genus Podosphaera, close to P. macularis (hop powdery mildew), was confirmed in the ITS-based phylogeny. The phylogenetic results, in concordance with the morphological traits of the flax powdery mildew (small peridial cells of the chasmothecia), place this species in Podosphaera sect. Sphaerotheca subsect. Sphaerotheca. Oidium lini, described from Croatia by Skoric in 1926, was later erroneously reduced to a synonymy with Golovinomyces orontii. Oidium lini has been reassessed and is now regarded as a synonym of Podosphaera lini. Oidium lini, cited in the literature as a name published by Bondartsev in 1913, is critically discussed and reviewed. The name O. lini was most likely never validly introduced and is doubtful.
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Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae (Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences - a taxonomic interpretation.
2013Co-Authors: Uwe Braun, Nina Shishkoff, Susumu TakamatsuAbstract:Abstract: Braun, U., Shishkoff, N. & Takamatsu, S. 2001: Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae ( Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences – a taxonomic interpretation. Schlechtendalia 7 : 45-52. Data of a phylogenetic analysis of the Podosphaera ( Sphaerotheca ) fuliginea complex based on rDNA ITS sequences are taxonomically interpreted. Using a morphological species concept, mainly based on the size of the ascomata and the diameter of the thin-walled apical portion of the asci (oculus), combined with biological data, the present taxonomic status of P. balsaminae, P. diclipterae, P. fuliginea, P. intermedia, P. pseudofusca and P. sibirica as separate species has been confirmed. P. fusca emend. as well as P. xanthii emend. are reassessed as complex, compound species. P. euphorbiae-hirtae and P. phaseoli are reduced to synonymy with P. xanthii . Zusammenfassung: Braun, U., Shishkoff, N. & Takamatsu, S. 2001: Phylogeny of Podosphaera sect. Sphaerotheca subsect. Magnicellulatae ( Sphaerotheca fuliginea auct. s.lat.) inferred from rDNA ITS sequences – a taxonomic interpretation. Schlechtendalia 7 : 45-52. Ergebnisse einer phylogenetischen Analyse des Podosphaera ( Sphaerotheca ) fuliginea -Komplexes auf Grundlage von rDNA-ITS-Sequenzen werden taxonomisch ausgewertet. Unter Anwendung eines morphologischen Artkonzepts, hauptsachlich auf Grundlage der Fruchtkorpergrose und des Durchmessers der dunnwandigen Scheitelregion der Asci (Oculus), in Verbindung mit biologischen Daten, wird der gegenwartige taxonomische Status von P. balsaminae, P. diclipterae, P. fuliginea, P. intermedia, P. pseudofusca und P. sibirica bestatigt. P. fusca emend. und P. xanthii emend. werden neu als komplexe Sammelarten bewertet. P. euphorbiae-hirtae und P. phaseoli werden zu P. xanthii gestellt.
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Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera, Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences, some taxonomic consequences
2000Co-Authors: Uwe Braun, Susumu TakamatsuAbstract:Abstract: Braun, U. & Takamatsu, S. 2000: Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera , Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences – some taxonomic consequences. Schlechtendalia 4 : 1-33. The very close relationship between the genera Erysiphe s.str. (= Erysiphe sect. Erysiphe ), Microsphaera , and Uncinula , which are connected by numerous intermediate taxa, is strongly supported by light as well as scanning electron microscopical features and has recently been confirmed by examinations of nucleotide sequences of rDNA internal transcribed spacers (ITS). Erysiphe s.str. and Microsphaera did not group into separate monophyletic lineage, but formed several small mixed clusters. It turned out that the formation of branched ascoma appendages does not have any taxonomic value at generic level. Therefore, Microsphaera is reduced to synonymy with Erysiphe s.str., and the new combinations, which are necessary, are introduced. Uncinula spp. form a basal subclade of the Erysiphe s.str./ Microsphaera ( Pseudoidium ) clade, but since some species of Erysiphe s.str. belong in this subclade, it is necessary to reduce Uncinula to synonymy with the latter genus, too. Erysiphe emend. is formally divided into sections for non-phylogenetical, but morphological groups of species, viz. Erysiphe sect. Erysiphe , E. sect. Microsphaera , and E. sect. Uncinula . Furthermore, examinations of nucleotide sequences of rDNA ITS regions of numerous taxa belonging to tribe Cystotheceae showed that Podosphaera and Sphaerotheca did not form separate monophyletic clades. Taxa of Sphaerotheca sect. Sphaerotheca and sect. Magnicellulatae grouped together with two different sets of Podosphaera spp. in two separate subclades of a single Podosphaera/Sphaerotheca clade. Based on these results and since Podosphaera and Sphaerotheca are morphologically only distinguished by having appendages which are branched and simple, respectively, it is proposed to merge the two genera. New combinations for Sphaerotheca spp. under Podosphaera are introduced. Podosphaera is formally divided into sections and subsections for non-phylogenetical, but morphological groups of species, viz. Podosphaera sec. Podosphaera , P . sect. Sphaerotheca subsect. Sphaerotheca , and subsect. Magnicellulatae . Furthermore, some changes of the classification of the Erysiphaceae are proposed. The following new combinations are introduced: Erysiphaceae tribe Cystotheceae subtribe Sawadaeinae, Erysiphaceae tribe Golovinomyceteae, Erysiphaceae tribe Golovinomyceteae subtribe Arthrocladiellinae and subtribe Neoerysiphinae. Zusammenfassung: Braun, U. & Takamatsu, S. 2000: Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera , and Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences – some taxonomic consequences. Schlechtendalia 4 : 1-33. Die enge Verwandtschaft zwischen den Gattungen Erysiphe s.str. ( = Erysiphe Sektion Erysiphe ), Microsphaera und Uncinula , die durch zahlreiche morphologisch untermediare Taxa verbunden sind, wird stark durch licht- und elektronenmikroskopische Merkmale unterstutzt und durch neue Untersuchungen der Nukleotidsequenzen der rDNA-ITS-Region bestatigt, da diese Gattungen nicht zu verschiedenen monophyletischen Linien gehoren. Erysiphe s.str. und Microsphaera bilden jedoch verschiedene kleine, gemischte Gruppen. Es hat sich herausgestellt, das die Bildung verzweigter Fruchtkorperanhangsel keinen taxonomischen Wert auf Gattungsebene hat. Deshalb wird vorgeschlagen, Microsphaera als Synonym von Erysiphe zu betrachten. Die notwendigen Neukombinationen werden eingefuhrt. Uncinula -Arten bilden ein “Subclade” an der Basis des “ Erysiphe s.str./ Microsphaera ( Pseudoidium )-Clades”. Da auch einige Erysiphe s.str.-Arten in dieses “Subclade” gehoren, ist es notwendig, diese beiden Gattungen zu vereinigen. Erysiphe Sektion Erysiphe, E. Sektion Microsphaera und E. Sektion. Uncinula . Untersuchungen von Nukleotidsequenzen ribosomaler DNA (ITS) zahlreicher Taxa der Cystotheceae zeigten, das Podosphaera und Sphaerotheca keine getrennten “Clades” bilden. Taxa von Sphaerotheca Sektion Sphaerotheca und Sektion Magnicellulatae bilden zusammen mit zwei verschiedenen Gruppen von Podosphaera -Arten getrennte “Subclades”. Auf Grundlage dieser Befunde und da Podosphaera- und Sphaerotheca -Arten morphologisch nur durch verzweigte und einfache Fruchtkorperanhangsel unterschieden sind, wird vorgeschlagen, beide Gattungen zu vereinigen. Neukombinationen von Sphaerotheca -Arten unter Podosphaera werden eingefuhrt. Podosphaera wird formal in folgende morphologisch, aber nicht phylogenetisch begrundete Sektionen und Subsektionen gegliedert: Podosphaera Sektion Podosphaera , P . Sektion Sphaerotheca Subsektion Sphaerotheca , und Subsektion Magnicellulatae . Weiterhin werden einige Anderungen der Klassifizierung der Erysiphaceae vorgeschlagen. Folgende Kombinationen werden eingefuhrt: Erysiphaceae Tribus Cystotheceae Subtribus Sawadaeinae, Erysiphaceae Tribus Golovinomyceteae, Erysiphaceae Tribus Golovinomyceteae Subtribus Arthrocladiellinae und Subtribus Neoerysiphinae.
Torres M. Francisco - One of the best experts on this subject based on the ideXlab platform.
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Fertiriego con silicio en variedades de rosa sobre la severidad de mildeo polvoso (Sphaerotheca pannosa var. rosae)
Tulio Cesar B., 2016Co-Authors: Albornoz Cesar, Silva P. Amanda, Torres M. FranciscoAbstract:La investigación evaluó el Fertiriego con silicio en la severidad del mildeo polvoso (Sphaerotheca pannosa var. rosae) en tres variedades de rosa bajo invernadero. Se empleó un diseño de parcelas subsubdividas; los tratamientos principales correspondieron a tres dosis de silicio (SiO2) (DS): (DS1=3mgL-1), (DS2=6mgL-1) y (DS3=9mgL-1); los sub-tratamientos a dos tipos de Fertiriego (L): (L1=3 mmdía-1), (L2=5 mmdía-1) y los sub-sub-tratamientos a tres variedades (V): (V1 = Vendela), (V2 = Reed Unique) y (V3 = Miracle). Se presentaron diferencias (p≤0,01) por el efecto de la DS (dosis de silicio), L (láminas de fertiriego) y V (variedades); como también de la interacción DS*L (p≤0,01). Las aplicaciones de DS3 redujeron el porcentaje de severidad del hongo (20%) y las de DS1 fueron menos eficientes (230%). Se obtuvieron menores porcentajes de severidad del hongo con la aplicación de la lámina de agua de fertiriego L1 (130%) y más altos con la L2 (280%). Las variedades V2 y V3 fueron menos afectadas por el hongo (170 y 160%) y la V1 fue más susceptible (320%). La dosis DS3 y la lámina de fertiriego L1 actuaron conjuntamente sobre una menor reducción del grado de severidad del hongo (75%) (p≤0,05). El comportamiento de las variedades Miracle y Reed Unique con una lámina de fertiriego de 3mmdía-1 y dosis de 9mgL-1 de Silicio, podrían ser claves para la disminución de la severidad de Sphaerotheca pannosa var. rosae en zonas productoras de flores de Colombia
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Fertiriego con silicio en variedades de rosa sobre la severidad de mildeo polvoso (Sphaerotheca pannosa var. rosae)
2016Co-Authors: Albornoz B. Cesar, Silva P. Amanda, Torres M. FranciscoAbstract:The research evaluated the Fertigation with silicon in the severity of the powdery mildeo (Sphaerotheca pannosa var. Rosae) in three varieties of rose under greenhouse. The experiment was a split-split plot design with silicon doses (DS) as the main-plot factor: (DS1 = 3mgL-1), (DS2 = 6mgL-1) and (DS3 = 9mgL- 1); Fertigation (L) as the sub-plot factor: (L1 = 3 mm day-1), (L2 = 5 mm day-1) and rose varieties (V) as the sub-sub-plot factor: (V1 = Vendela), (V2 = Reed Unique) and (V3 = Miracle). There were differences (p≤0.01) due to the effect of SD (silicon dose), L (fertigation) and V (varieties); As well as the DS * L interaction (p≤0.01). DS3 applications reduced fungus severity (20%) while DS1 was less efficient (230%). Lower percentages of fungal severity were obtained with Fertigation L1 (130%) and while L2 had the higher (280%). Varieties V2 and V3 were less affected by fungus (170 and 160%) while V1 was more susceptible to it (320%). The DS3 dose and the L1 fertigation interaction reduced fungal severity (75%) (p≤0.05). The behavior of the Miracle and Reed Unique rose varieties with a 3-mm.day-1 fertigation and a silicon dose of 9mgL-1 could be key to decreasing the severity of Sphaerotheca pannosa var. Rosae in flower growing areas of Colombia.La investigación evaluó el Fertiriego con silicio en la severidad del mildeo polvoso (Sphaerotheca pannosa var. rosae) en tres variedades de rosa bajo invernadero. Se empleó un diseño de parcelas subsubdividas; los tratamientos principales correspondieron a tres dosis de silicio (SiO2) (DS): (DS1=3mgL-1), (DS2=6mgL-1) y (DS3=9mgL-1); los sub-tratamientos a dos tipos de Fertiriego (L): (L1=3 mmdía-1), (L2=5 mmdía-1) y los sub-sub-tratamientos a tres variedades (V): (V1 = Vendela), (V2 = Reed Unique) y (V3 = Miracle). Se presentaron diferencias (p≤0,01) por el efecto de la DS (dosis de silicio), L (láminas de fertiriego) y V (variedades); como también de la interacción DS*L (p≤0,01). Las aplicaciones de DS3 redujeron el porcentaje de severidad del hongo (20%) y las de DS1 fueron menos eficientes (230%). Se obtuvieron menores porcentajes de severidad del hongo con la aplicación de la lámina de agua de fertiriego L1 (130%) y más altos con la L2 (280%). Las variedades V2 y V3 fueron menos afectadas por el hongo (170 y 160%) y la V1 fue más susceptible (320%). La dosis DS3 y la lámina de fertiriego L1 actuaron conjuntamente sobre una menor reducción del grado de severidad del hongo (75%) (p≤0,05). El comportamiento de las variedades Miracle y Reed Unique con una lámina de fertiriego de 3mmdía-1 y dosis de 9mgL-1 de Silicio, podrían ser claves para la disminución de la severidad de Sphaerotheca pannosa var. rosae en zonas productoras de flores de Colombia
Timothy Pettitt - One of the best experts on this subject based on the ideXlab platform.
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first record of oidium anamorph of podosphaera xanthii on medusagyne oppositifolia
Plant Pathology, 2010Co-Authors: Timothy Pettitt, B Henricot, D Matatiken, R T A CookAbstract:Powdery mildew first appeared on mature 3-year-old bushes of ‘jellyfish tree’, Medusagyne oppositifolia (Medusagynaceae), grown from seed at Eden Project, Cornwall, England, in collaborative conservation work with the Seychelles Government. Initially, young leaves showed distortion and patches of mycelium bearing conidia. Later, light brown lesions developed and badly affected plants showed extensive leaf-drop, especially destructive in seedlings. This is the first report of powdery mildew on Medusagyne. Conidia are catenate, elliptical to doliiform, (19) 24–34(47AE5) · (13AE5) 15–18 lm with fibrosin bodies and a sinuous wrinkling pattern. Conidiophores erect with a long cylindrical straight or twisted foot-cell, 41–86AE5 (140) · (7) 9–14 (16) lm, arising towards one end of its hyphal mother cell, the lower septum occasionally raised up to 10 lm, followed by a generative cell and 2–5 maturing conidial units. Superficial hyphal cells, 25–105 · 4AE5–11AE5 lm, branched at right angles, bearing inconspicuous or slightly nipple-shaped appressoria. No chasmothecia were present, but characteristics are consistent with Oidium subgenus Fibroidium, the anamorph of Podosphaera. The short, broad germ tubes typical of the fibroidium type, brevitubus subtype narrowed the identification to Podosphaera section Sphaerotheca subsect. Magnicellulatae (Cook & Braun, 2009) with the morphology close to that of Podosphaera (syn. Sphaerotheca) fusca, apparently a ubiquitous species with a broad host range.
