Fungal Like Organisms (Protists and Chromist) Phyla not apart of the fungi kingdom

What are Protists and Chromists?

Before Chromista was erected, any eukaryotes that weren’t animals, plants, or fungi were place in Protista.

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Chromists is a new group; that arose ancestrally eukaryote- eukaryote chimaeras that arose by symbiotic enslavement of a eukaryote (red algae)

(eukaryotes merged to make Chromists; one eukaryote enslaves another.)

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Protists are a garbage can group; arose ancestrally **monophyletically** by the origin of the eukaryote cell and a prokaryote cell and its enslavement of a symbiotic purple bacteria to make mitochondria.

(prokaryote cell is purple bacteria that turn into mitochondria)

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These groups look similar but are distinct, they have **converged** (not related but share characteristics)

Myxomycota

Known as slime molds(move like slime)

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Not important as plant parasites

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Can colonize grass blades (hanging out in glass blades)

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More of a visual problem than a plant pathogen

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Probably a chromist

The slime mode; a member of the class Myxomycetes, aka the dog vomit fungus

**Fuligo**

Badhamia uticularis

eats fungi decomposing wood

Physarum cinereum is found in

the grass

Life cycle of Myxocete

Has diploid and haploid stage

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Start at mature fruiting bodies

Plasmodiophormycota

Plasmodiophara brassicae

causes club root of cabbage family

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Spongospora subterranea

causes powdery scab of potato and transports potato mop top virus

Club roots of Brassicas

Occurs only on Brassicas(mustards aka cabbages)

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Favored by cool, wet soil and low pH

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Survives ten or more years in the soil

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Very difficult to manage

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Crop rotation

Main reason we switch crops is to stop and kill pathogens.

Plant cells with A B C

A: Host cell with profiles of multiple young sporogenic plasmoida.

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B and C: Cells fillied..

Start with resting spores

Disease cycle of clubroot

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Thursday, March 2, 2023 at 12:26:11 PM (panopto.com)

Best way to manage club root of cabbage

Change pH in the soil

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Soil usually in 5-6 pH range

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Club like roots appear in said range.

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Change pH with lime and get the soil to 8 the pathogen gets into roots and will infect soil but no symptoms will arise.

Best way to manage club root of cabbage

grow resistant crops

Powdery scab of potato

Caused by Spongospora subterranea

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Spongospora can survive for 18 years in the soil without the hosts

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Spongospora can damage the potato directly and transmit the potato mop top virus, which was 1st discovered in the US in 1992

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crop rotation doesn’t work on this as spores only wake up when potato is cropped; they can detect the chemicals in the soil.

Resting Sturctures

Soil-borne plant pathogens are those that survive in the soil and primarily cause diseases of roots, crown, and fruit on the ground.

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In order to survive, they produce various structures that are discussed below.

**Oospores**

Sexual spores produced by oomycetes; they can survive for many years in the soil

Chlamydospores

Thick-walled microscopic resting spores that allow fungi and oomycetes to survive long periods of time(years) in the soil

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Shown here in chains, but single cells

Sclerotia (Sclerotium, singular)

Not a spore; more like a mushroom

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A compact mass of hyphae, usually with a rind

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Most sclerotia are large enough to see the eye

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Can survive many years in the soil

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Produced by ascomycetes and basidiomycetes.

Resting structures of smuts are

Teliospores but smuts aren’t soil-born soil-borne pathogens and teliospores only survive on top of the ground.

Resting structures of rusts are

Teliospores; overwinter in plant material on top of the ground

Summary of resting structures

Sclerotia multicellular, vegatative and macroscopic

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Chlamydospore: thick-walled spore, vegatitive and microscopic

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Oospore: sexual and microscopic

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Zygospore: sexual and microscopic

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Teliospore: asexual and microscopic produced by smuts and rusts(basidiomycetes)