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Basidiomycetes
- saprophytes
- rusts- 4 spore types + male gametes
- smuts- 2 spore types
- produce basidiospores on basidia (sexual)
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Rusts
- Obligate pathogens
- one species but different races affect different hosts
- Heteroecious- two different hosts
- autoecious- one host
- Rust color is repeating spore urediniospores
- Black color is overwintering spore basidiospores
- Spetate w/ Clamp connections
- club fungi
- some poly cyclic
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Rust Spore Types
- Teliospores- over winter, aren't infectious, black // produces basidiospores
- Basidiospores- infect alternate host and produce mycelium that form spermagonia
- Spermatia & receptive hyphae- recombination, don't infect // form aeciospores on alternate host
- Aeciospores- infect host & produce mycelium
- Urediniospores- infect host and produce more uredospores, secondary inoculum
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Coffee Rust
- Started in Ethiopia in middle east 1500s
- 1600s coffee houses were the big thing
- Monoculture then 1860s rust spread rapid
- Didn't get to S. America til 1970s
- Everywhere but Hawaii
- Choleric spots and urdiniospores under leaf
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Wheat Rust
- Greeks knew about it
- Barbarry
- Barbarry eradication
- but ureodiniospores can blow north
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Ceder Apple Rust
- Symptoms: Galls on cedar trees, swollen areas, deformed apples
- Signs: Jelly-like horns, spermagonia on top
- Conditions: wet spring, dry summer
- Management: Fungicides
- Monocyclic- no secondary inoculum
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Corn Smut
- Utilago maydis
- Monocyclic
- Basidiospores- infect
- black teliospores over winter
- Sexual reproduction only
- no alternate host
- septate w/ clamp connection
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Wheat Smut
- Sticking smut
- Tilletia tritici
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General disease cycle of smut
- overwinter in vegetative hypeae in roots
- Systematic infection
- teliospores (plant sterile)
- Basidiospores (looks like yeast)
- Fusion (all happens on surface)
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Bacteria
- ice nucleators
- cell membrane, cell wall, flagella, slime layer
- rod shaped
- like warm and wet
- Can move in the clouds
- reproduce by fusion not spores
- exponential growth then level off
- Plasmids and large DNA in circle
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Mollicutes
- (mycoplasma like organisms – MLOs)
- phytoplasmas and spiroplasmas
- no cell wall
- pleomorphic (have various shapes)
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Bacteria Taxonomy
- Gram Negative:
- Agrobacterium
- Pseudomonas
- Xanthonmonas
- Erwinia
- Gram Positive:
- Clavibacter
- Streptomyces
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Pathovar
strains of the same species that differ only in the hosts that they infect are designated as pathovars of the species
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Soil inhabitants
- survive for extended periods of time (yrs) in soil
- eg Agrobacterium- picked up from soil, causes crown gull
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Soil invaders
- enter the soil in host tissue and remain there until host tissue decays or as saprophytes for varying times
- Most bacteria stay in host tissue not good saprophytes
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Agrobacterum Symptoms
- crown gall
- harry root
- over production of host tissue
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Clavibacter symptoms
- Potato ring rot
- gram positive
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Erwinia
blight, wilt, soft rot
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Infection Process of Bacteria
- 1. build up population (quorum sensing)
- 2. Migration of bacteria to entry sites (need water)
- 3. Bacterial entry into plant tissue
- through wounds & natural opening
- 4. Movement in plants- intracellular and passive through vascular
- 5. Chemical Weapons (toxins- dead spots, Enzymes, plant hormones- Agrobacter)
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Spread of Bacteria
- Water
- Insects
- Animals
- Human Activity
- infected seed/plant part
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