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Leveillula Stock Photos and Images

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Leveillula Stock Photos and Images

Powdery mildew (Leveillula taurica) infection on sweet pepper leaf, Portugal Stock Photo
RMBXGHRA–Powdery mildew (Leveillula taurica) infection on sweet pepper leaf, Portugal
Zucchini crop infested by Leveillula Taurica, close-up Stock Photo
RF2APM5TJ–Zucchini crop infested by Leveillula Taurica, close-up
Powdery mildew Leveillula taurica infection on sweet pepper leaf Portugal Stock Photo
RMAXHTEM–Powdery mildew Leveillula taurica infection on sweet pepper leaf Portugal
Close up of tomato green leaf with brown spots and dry endings. Plant diseases concept Stock Photo
RF2GYYJN4–Close up of tomato green leaf with brown spots and dry endings. Plant diseases concept
. Comparative morphology of Fungi. Fungi. 202 COMPARATIVE MORPHOLOGY OF FUNGI by the special structure of the perithecial rind. Before the rind has completed its peridial structure, some of its cells develop to long append- ages; these are generally characteristic and offer one of the most conven- ient points for the separation of genera. In Erysiphe, Leveillula (Fig. 127) and Sphaerotheca, they are simple, hyphal-like and intertwined with the mycelium; in Podosphaera (Fig. 128, 4) and Microsphaera (Fig. 128, 1 to 3), they are repeatedly dichotomously branched at the tips; in Uncinula (Fig. 12 Stock Photo
RMREF8CR–. Comparative morphology of Fungi. Fungi. 202 COMPARATIVE MORPHOLOGY OF FUNGI by the special structure of the perithecial rind. Before the rind has completed its peridial structure, some of its cells develop to long append- ages; these are generally characteristic and offer one of the most conven- ient points for the separation of genera. In Erysiphe, Leveillula (Fig. 127) and Sphaerotheca, they are simple, hyphal-like and intertwined with the mycelium; in Podosphaera (Fig. 128, 4) and Microsphaera (Fig. 128, 1 to 3), they are repeatedly dichotomously branched at the tips; in Uncinula (Fig. 12
Powdery mildew Leveillula taurica infection on sweet pepper leaf Portugal Stock Photo
RMAXHTJN–Powdery mildew Leveillula taurica infection on sweet pepper leaf Portugal
Powdery mildew (Leveillula taurica) infected tomato crop in polytunnel, Portugal Stock Photo
RMBJR3AJ–Powdery mildew (Leveillula taurica) infected tomato crop in polytunnel, Portugal
. Comparative morphology of Fungi. Fungi. PERISPORIALES 195 prefer damp climates. The only endophytic species, Leveillula taurica, belongs to dry subtropical regions whose phanerogams are generally xerophytes with a very thick epidermis. Further it appears that the Erysiphaceae in the tropics generally only propagate by imperfect forms and that the perithecia degenerate. They are also sharply specialized even in their ectophytism (Salmon, 1900, 1903; Steiner, 1908; Blumer, 1922; etc.). From the numerous forms so far studied, except for Erysiphe dehoracearum, none is able to go beyond a single Stock Photo
RMREF8FE–. Comparative morphology of Fungi. Fungi. PERISPORIALES 195 prefer damp climates. The only endophytic species, Leveillula taurica, belongs to dry subtropical regions whose phanerogams are generally xerophytes with a very thick epidermis. Further it appears that the Erysiphaceae in the tropics generally only propagate by imperfect forms and that the perithecia degenerate. They are also sharply specialized even in their ectophytism (Salmon, 1900, 1903; Steiner, 1908; Blumer, 1922; etc.). From the numerous forms so far studied, except for Erysiphe dehoracearum, none is able to go beyond a single
Powdery mildew Leveillula taurica mycelium on the underside of an infected tomato leaf Stock Photo
RMAT9N2R–Powdery mildew Leveillula taurica mycelium on the underside of an infected tomato leaf
. Comparative morphology of Fungi. Fungi. 210 COMPARATIVE MORPHOLOGY OF FUNGI direction of the Sphaeriales, it may become many layered. In many species, as in Erysiphe and Leveillula of the Erysiphaceae, it is symmetri- cal throughout the fructification; in others, as in Microsphaera and Uncinula, it is dorsiventral and is drawn out to a small wart or papilla at the tip; in other species, as in Meliola corallina (Fig. 132, 2), as a definite step in the direction of the Sphaeriales, a true opening, an ostiole, is formed at the top of the perithecium (Bucholtz, 1897). At times the perithecia, as Stock Photo
RMREF89J–. Comparative morphology of Fungi. Fungi. 210 COMPARATIVE MORPHOLOGY OF FUNGI direction of the Sphaeriales, it may become many layered. In many species, as in Erysiphe and Leveillula of the Erysiphaceae, it is symmetri- cal throughout the fructification; in others, as in Microsphaera and Uncinula, it is dorsiventral and is drawn out to a small wart or papilla at the tip; in other species, as in Meliola corallina (Fig. 132, 2), as a definite step in the direction of the Sphaeriales, a true opening, an ostiole, is formed at the top of the perithecium (Bucholtz, 1897). At times the perithecia, as
Powdery mildew Leveillula taurica infected tomato crop with damage on upper and lower surfaces Stock Photo
RMAT9N8P–Powdery mildew Leveillula taurica infected tomato crop with damage on upper and lower surfaces
Powdery mildew (Oidium lini) infection of linseed plants Stock Photo
RMBX75RM–Powdery mildew (Oidium lini) infection of linseed plants
Oidium or Powdery mildew Leveillula taurica on tomato leaves Portugal Stock Photo
RMA2GT86–Oidium or Powdery mildew Leveillula taurica on tomato leaves Portugal
. Comparative morphology of Fungi. Fungi. CI f^ ktfuj 'â¢'â â '/â â "" »;,*;..- f'* *.. â â "â Mi &$j i&-:^ â m .*»â¢â¢â -V ivS- :£>;;: v& *w*. ⢠/ fi ift i! ?4; â M | ft :.;-^ J" â .'****.: 'â i':**',' :â " i t -â : *" r*-*' â¢' Y â -l r<^-... W-. Fig. 123.âSphacrotheca Humuli. Development of conidiophore. (X830; after Foex, 1913.) conidia are cut off singly, in the ectoparasitic forms they arise in chains (Foex, 1912, 1913; Bezsonov, 1913). In the first type, Leveillula taurica (Fig. 122), the hyphae collect in the substomatal cavity to Stock Photo
RMREF8EM–. Comparative morphology of Fungi. Fungi. CI f^ ktfuj 'â¢'â â '/â â "" »;,*;..- f'* *.. â â "â Mi &$j i&-:^ â m .*»â¢â¢â -V ivS- :£>;;: v& *w*. ⢠/ fi ift i! ?4; â M | ft :.;-^ J" â .'****.: 'â i':**',' :â " i t -â : *" r*-*' â¢' Y â -l r<^-... W-. Fig. 123.âSphacrotheca Humuli. Development of conidiophore. (X830; after Foex, 1913.) conidia are cut off singly, in the ectoparasitic forms they arise in chains (Foex, 1912, 1913; Bezsonov, 1913). In the first type, Leveillula taurica (Fig. 122), the hyphae collect in the substomatal cavity to
Oidium or powdery mildew Leveillula taurica on sweet pepper leaves Capsicum annuum Stock Photo
RMA2GT89–Oidium or powdery mildew Leveillula taurica on sweet pepper leaves Capsicum annuum
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