Rhizopus sp. on peach
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Transcript of Rhizopus sp. on peach
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Rhizopus sp. on peach
Rhizopus sp. on sunflower
Plant Pathology – G.N. Agrios
TRUE FUNGI
ASCOMYCETES - called the sac fungi because sexual spores (ascospores) are produced in a sac (ascus).
This is the largest group of fungi (35k +)with the most economically important members.
ASCOMYCETESCharacteristics :1. Most are facultative parasites - they can survive in
soil or plant debris, often for several years. A few are obligate parasites.
2. They produce a cellular hyphae (i.e., with distinct cell cross walls).
3. They produce a stroma - a mass of hyphae in which fruiting bodies are produced.
4. Sexual spores = ascospores. They are produced in groups of 8, which are enclosed in a single ascus (asci).
5. Ascospores in asci are produced in an ascocarp.There are several basic types of ascocarps, but each
fungus produces only one type:
Plant Pathology – G.N. Agrios
Ascocarps
a. Naked - asci are produced exposed on a plant surface, i.e., not in an ascocarp.
Ex: Taphrina deformans - peach leaf curlEx: Saccharomyces spp. - the yeasts
Naked - asci
Ascocarpsa. Naked - asci are produced exposed on a plant surface, i.e., not in an
ascocarp.
b. Cleistothecia - asci are produced in a completely closed spherical structure.
Ex: Sphaerotheca pannosa - powdery mildew of roseEx: Erysiphe graminis - powdery mildew of wheat
Plant Pathology – G.N. AgriosPlant Pathology – G.N. Agrios
Cleistothecia
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Ascocarpsa. Naked - asci are produced exposed on a plant surface, i.e., not in an
ascocarp.b. Cleistothecia - asci are produced in a completely closed spherical structure.
c. Perithecia - asci are produced in a nearly-completely closed structure with a single opening and a distinct wall. Perithecia can be round or some version of flask-shaped.
Ex: Claviceps purpurea - ergot of grains
Ex: Ophiostoma ulmi - Dutch elm disease
Ex: Cryphonectria parasitica - chestnut blight
Plant Pathology – G.N. Agrios
Perithecia
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Ascocarpsa. Naked - asci are produced exposed on a plant surface, i.e., not in an
ascocarp.b. Cleistothecia - asci are produced in a completely closed spherical
structure.c. Perithecia - asci are produced in a nearly-completely closed structure
with a single opening and a distinct wall. Perithecia can be round or some version of flask-shaped.
d. Apothecia - asci are produced in an open cup- or saucer-shaped structure.
Ex: Monilina fructicola – brown rot of stone fruitsEx: Sclerotinia sclerotiorum - white mold of bean
Plant Pathology – G.N. Agrios
Apothecia
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Ascocarpsa. Naked - asci are produced exposed on a plant surfaceb. Cleistothecia - asci are produced in a completely closed spherical
structure.c. Perithecia - asci are produced in a nearly-completely closed
structure with a single opening. Perithecia can be round or some version of flask-shaped.
d. Apothecia - asci are produced in an open cup- or saucer-shaped structure.
e. Pseudothecia (aka ascostroma) - asci are produced in cavities without a distinct wall within a stroma of mycelium within host tissues.
Ex: Venturia inaequalis - apple scabEx: Guignardia bidwellii - black rot of grape
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PseudotheciaAPS Slide Collection
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Ascocarpsa. Naked - asci are produced exposed on a plant surfaceb. Cleistothecia - asci are produced in a completely
closed spherical structure.c. Perithecia - asci are produced in a nearly-
completely closed structure with a distinct wall with a single opening. Perithecia can be round or some version of flask-shaped.
d. Apothecia - asci are produced in an open cup- or saucer-shaped structure.
e. Pseudothecia (aka ascostroma) - asci are produced in cavities without a distinct wall within a stroma of mycelium produced within host tissues.
Teleomorph vs AnamorphTeleomorph vs AnamorphThe The teleomorph teleomorph
(perfect stage)(perfect stage) is is the sexual stagethe sexual stage
The The anamorphanamorph (imperfect (imperfect stage)stage) is the is the asexual stageasexual stage
NectriaNectria - peritheciaperithecia FusariumFusarium - conidiaconidia
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