Test 2 Flashcards
4 main groups of disease causing fungi:
Ascomycota Basidiomycoda Chytridiomycota ZygoMycota
Example of Ascomycetes:
yeasts, cause:apple scab, chestnut blight, and dutch elm disease, also various cankers, leaf spots, powdery mildews.
Ascomycetes are? (4)
Obligate parasites, facultive parasites, and saphrophytes, obligate saphrophytes.
______ have Haploid septate, and many produce sclerotia.
Ascomycetes.
Sexual spores of ascomycetes:
ascospores
Asexual Spores of Ascomycetes:
conidia
Asexual stages usually serve as ______ innoculum, Ascospores usually are ______ innoculum,or overwintering stage.
secondary primary
Wood decay pathogens, mushrooms,puffballs, conks, smut fungi and rust fungi.
Basidiomycota and Basidiomycetes
Basidomyctoa: Smut fungi are _______
facultative saprophytes
Basidomyctoa: Rust fungi are _______
obligate parasites.
Basidomycota have ________ Hyphae and ___ ____ that form at some septa of their hyphae. Unique to this group.
dikaryotic, clamp connections.
basidospores
sexual spores-two hapliod nuclei fuse(Karyogamy) in basidum. then undergo meiosis to form 4 haploid nuclei. Haploid, Infect alternate host to form pycnia.(fruiting structure)
smut fungi produce sexual spores called
sporidia
Chlymadiospores-
think or doublewalled asexual resting spore developed by modification of a hyphal cell or transformation of conidial cells. can be overwintering stage.
Teliospores-
Dikaryotic spores, become diploid, germinate to form basidia and basidiospores or sporidia
Rust Fungi- and infection symptoms.
most destructive of plant diseases, attack mainly leaves and stems. appear orange,red,and white(rust colors)
Autoecious-
requires a single host to complete their life cycle.
Heteroecious-
required two unrelated plant species to complete its life cycle.
Pycniospores also called_______ are _______ and combine with________ to end up forming a dikaryotic mycelium.
spermatia asexual receptive hyphae
Aeciospores-
Dikaryotic ,asexual infects primary host. gives rise to uredinospores or teliospores. Cupshaped.
Urediniospores-
Dikaryotic, asexual. Repeating cycle of rust fungi.
How to manage fungual diseases:
- Correctly identify pathogen. 2.Know the disease cycle. 3.Integrated management approaches are most successful. 4.Can use avoidance,exclusion, eradication and/or protection.
Avoidance-
choose planting sites or times to avoid environmental conditions favoring disease.
Exclusion-
international or local quarantines or pathogen free seed.
Eradication-
Crop rotation, remove infected hosts, remove weed hosts, prune and remove infected parts of woody plants, disinfect tools.
Protection-
Fungicides,minimize leaf wetness, plant resistant cultivars, cultural practices.
Coccal -shape
round
Rod shaped-
bacilliform
Mollicutes-
no cell walls, only cell membranes
Phytoplasmas
pleomorphic or variably shaped
Spiroplasms
helical
Bacteria that produce long branched filiments, live in soil and produce antibiotics.
Actinobacterium orActinomycetes
cytoplasm
mixture of organic compounds,minerals, and water.
Extracellular Polysaccharide(EPS)
Secreted by many bacteria, attached to the exterior surface of cells as slime layer(capsule). promotes disease process.
Flagella-
external structures that rotate and move cells short distances.
polar- Peritrichous-
located at the ends of cells. all over the cell
Nuclear material-
one large circular ‘chromosome’ composed of DNA.
Plasmids-
additional, smaller circular genetic material.
Bacteria reproduce by? and explain it.
Fisson, cell splits in exactly 2 parts. DNA and plasmids also duplicate. may divide every 20-50 mins, and 1 can be 1million in a day.
Fastidious-
cultured only on complex, specialized media.
Gram positive-
thick cell walls, stain purple with gram stain procedure.
Gram negative-
thin cell wall, purple stain does not maintain. stained pink, most plant pathogenic bacteria.
Bacteria survival in soil:
only on plant material Saprophytically in their natural bacterial ooze.
Bacteria survival in plants:
as parasites, epiphytically(on surface), on wounds or in buds, in plant exudate.
How do bacteria move? and how do they enter plants?
water,insects, animals. need water to infect. through natural openings or wounds.
Bacteria in plants
live and multiply in intercellualr spaces,stems, leaves,flowers and galls, degrade plant cells, colonize dead cells
Agrobacterium
Rhizosphere and soil inhabitants aerobs. motile, abundant EPS Gram-negative.
Erwinia
causes necrosis or wilt disease, soft rots.
Pseudomonas
polar flagella, aerobes, gram negative. leaf spots, blights, wilts.
Xanthomonas
Motile, one polar flagella, yellow colonies.
Clavibacter
non-motile,aerobes. irregularly shaped rods.
Streptomycets
produced branched,non-septate hyphae and spores (conidia) produced antibiotics, gram-positive
Xylella
Nonmotile; fastidious bacteria. Live in plant xylem.
Bacterial ooze-
sticky liquid composed of EPS and bacterial cells
Symptoms of Bacteria
Leaf spots and blights, sort rots of fruits, roots and storage organs water soaking wilts galls scabs and cankers
Soft rots-
involve parenchyma tissue of various plant organs.results in slimy decay
Leaf Spots-
involve leaf and stem parenchyma cells
Blight-
sever sudden and extensive spotting,discoloration, wilting, or destruction of plants or plant parts.
Scorch-
Necrosis on leaf edge; looks like fire.
Galls-
hyperplasia and hypertrophy
Cankers-
Tissue becomes sunken following necrosis.
Witches broom-
phloem colonizing bacteria
Scabs
scabby lesions
How to manage bacteria:
Exclusion ,eradication, and protection.
Apothecium
Sexual
Ascospore
Chasmothecium
Sexual
Ascospore
Pycnidium
Asexual
Conidia
Acervulus
asexual
Conidia
Pycnidum
asexual
Conidia
Telium
asexual
Basidiomycetes
Aecium
Asexual
Basidiomycetes
Uredium
Asexual
Basidiomycetes
Zygospore
Sexual
Zygomycetes
Sporangia
Asexual
Zygomycetes
