Exam 1 Flashcards
(177 cards)
1
Q
Define phytopathology.
A
Study of plant suffering
2
Q
Three F’s for studying plant suffering?
A
Food, fuel, fiber
3
Q
Which interaction has 0 effect on either species?
A
Neutralism
4
Q
Which interaction negatively affects species 1 and 0 effect on species 2? (one inhibits the other)
A
Ammensalism
5
Q
Which interaction has a positive effect on species 1 and 0 effect on species 2?
A
Commensalism
6
Q
Which interaction is favorable to both species, but not obligatory?
A
Synergism
7
Q
Which interaction is favorable to both and obligatory?
A
Mutualism
8
Q
Which interaction is negative to both and mutually inhibitory?
A
Competition
9
Q
Which interaction is negative to species 1 and positive to species 2 (one feeds on another?)
A
Predation
10
Q
Which interaction is negative to species 1 and positive to species 2 (one lives in intimate contact with the other, deriving nutrients?)
A
Parasitism
11
Q
The relationship of parasite to host is _____ only.
A
Nutritional
12
Q
Pathogens get ____ from the host, but also cause ____.
A
Nutrients; disease
13
Q
Any malfunctioning of host cells and tissues that results from continuous irritation by a pathogenic agent or environmental factor and leads to the development of symptoms?
A
Disease
14
Q
Short-term, mechanical abnormality
A
Damage
15
Q
Long-term, disturbance of plant metabolism caused by pathogens
A
Disease
16
Q
Two primary causes of disease
A
Biotic/Abiotic
17
Q
Alterations in the host caused by disease, progressing over time and characteristic of a particular disease
A
Symptoms
18
Q
3 factors of the disease triangle
A
Susceptible host, pathogen, conducive environment
19
Q
Biotrophs feed on…
A
living things
20
Q
Necrotrophs feed on…
A
dead thing
21
Q
Semi-biotrophs are a…
A
mixture of both
22
Q
Hemibiotrophs…
A
spend part of their life cycle as biotrops and part as necrotrophs
23
Q
Which lifestyle requires a living host to grow and reproduce, do not compete in the environment and usually cannot be grown in pure culture? (They are obligate parasites).
A
Biotrophs
24
Q
Which lifestyle feeds primarily on dead organic matter but can also colonize living tissue, kills cells before feeding on them, and often produces toxins? (Facultative parasites, opportunistic pathogens)
A
Necrotrophs
25
Which lifestyle primarily feeds on living hosts, but are also capable of living in dead host tissue/other organic matter? They may have a two-stage life cycle and are facultative saprotrophs.
Semi-biotrophs or hemibiotrophs
26
Has the ability to eat decaying things
saprotroph
27
Strong saprotrophs, weak pathogens, necrotrophs
Soil inhabitants
28
Weak saprotrophs, strong pathogens, biotrophs
Soil survivors
29
Uses signs, symptoms and tests for presence of a pathogen to identify a disease or other problem. It relies on existing knowledge and is not proof.
Diagnosis
30
```
Which plant malfunction category?
Nutrient deficiency
Nutrient toxicity
Water imbalance
Wind
Hail
Sunburn
Frost damage
Lightening
Chemical
```
Abiotic
31
```
Which plant malfunction category?
Insects
Mites
Browsing/grazing
Burrowing
Marking
Urination
```
Pests
32
```
Which plant malfunction category?
Bacteria
Fungi
Stramenopiles
Plasmodia
Nematodes
Viruses
```
Parasites and pathogens
33
Approximately ___% of plant problems are abiotic.
50
34
How to distinguish abiotic from biotic? 5 things
```
What does normal look like?
Symptom pattern?
Environmental history?
Soil characteristics?
Weather?
```
35
Blossom end rot is caused b a deficiency in ____.
Calcium
36
Nutrient toxicity can mimic ______.
Pathogenic agents
37
Girdling, root damage, soil compaction
Examples of physical damage
38
4 Challenges in identifying plant diseases
Inadequate information
Pathogen absent
Multiple possible problems match symptoms
Multiple problems present
39
Diagnosis or proof?
| Based on associations and confidence levels vary
Diagnosis
40
Diagnosis or proof?
| Defined series of steps to demonstrate pathogenicity (Koch's postulates)
Proof
41
Birth of agriculture was ~_____ BCE and was primarily ______ in the ______
10,000; Wheat/barley; fertile crescent.
42
Which plant disease contributed to the fall of the Roman Empire?
Wheat rust
43
Wheat rust is caused by which pathogen? What kind of pathogen is it?
Puccinia graminis (fungus)
44
Puccinia graminis: Biotroph or necrotroph?
Biotroph
45
Who described crop devastation in ~350 BCE?
Aristotle
46
Who provided a meticulous description of rust disease?
Theophrastus
47
Who is the deity of cereal rust in Roman times?
Robigus
48
What fungal pathogen causes Ergot of Rye?
Claviceps purpurea
49
What disease causes delusions/hallucinations and also burning sensations?
Ergotism (Holy Fire)
50
St. Anthony's Fire referenced what disease?
Holy Fire (Hospital dedicated to disease)
51
Who linked Ergotism to rye?
Thuillier
52
Who produced 1st mass produced microscopes?
Van Leeuwehoek
53
Who started taxonomy of living things?
Robert Hook
54
3 men of Germ Theory
Pasteur, Koch, deBary
55
Who disproved spontaneous generation?
Pasteur
56
4 Koch's Postulates
1. Organism found in diseased but not healthy hosts.
2. Isolate organism in pure culture
3. Culture causes same disease when introduced int healthy hosts
4. Same organism can be isolated from second host
57
Potatoes are native to...
South America
58
Potato Blight Years
1845-1860
59
Who proved pathogenicity of late potato blight using Koch's postulates?
Anton deBary
60
Which pathogen causes late potato blight?
Phytophthora infestans
61
Name the disease:
| Cankers on branches and trunk, wilting and death, resprouting from base
Chestnut blight; cryphonectria parasitica
62
6 Steps of Disease Cycle
```
Inoculation
Attachment
Penetration
Infection
Colonization & Growth
Reproduction & Dissemination
```
63
3 most common methods of pathogen dispersal
Wind, water, vectors
64
Which stage of the disease cycle?
| Introduction of pathogen onto susceptible host tissue
Inoculation
65
infective unit of a pathogen
inoculum
66
Inoculum produced on dormant structure that survives unfavorable season; causes initial infections at start of growing season
Primary inoculum
67
Inoculum produced on host plant from primary infections; causes secondary infections throughout growing season
Secondary inoculum
68
Which stage of the disease cycle?
Recognition of the host; production of adhesives and surface-degrading enzymes; pertains to bacteria, fungi, parasitic plants
Attachment
69
Time spent on the surface of the host before penetration
Incubation
70
Which stage of the disease cycle?
| Germ tube formation and extension; creates opening into plant (directly, naturally, through wounds or vectors)
Penetration
71
Penetration structure with tight adhesion, enzymes and turgor pressure
Appressorium
72
Thin hypha pushed through cuticle by appressorium
Penetration peg
73
How do fungal biotrophs penetrate?
Appressorium
74
How do fungal semi-biotrophs penetrate?
Hyphae from spore or mycelium
75
How do fungal necrotrophs penetrate?
Kill cells, enter through wound
76
How do parasitic plants penetrate?
Appressorium
77
Which stage of the disease cycle?
| Pathogen establishes contact, starts feeding (one host cell)
Infection
78
Which stage of the disease cycle?
| Symptoms appear
Colonization and growth
79
Time between inoculation and appearance of symptoms
incubation period
80
time between infection and appearance of symptoms
latent period
81
Which stage of the disease cycle?
| The pathogen reproduces and spores are spread via air, water, vector, or other methods.
Reproduction & Dissemination
82
Which is the dormant stage and may occur at various stages on or off the host?
Survival
83
An opisthokont has ____ flagellum/flagella.
One
84
Heterotrophic eukaryote feeding by absorptive nutrition with a single-celled or filamentous body plan; cell walls with glucan and chitin; reproduces by spores
Fungi
85
Cylindrical, branching filament with tubular cell walls; multinucleate; grows by tip elongation
Hyphae
86
Collective hyphae of an individual fungus
Mycelium
87
Single fungal cells reproducing by budding of fission
Yeast
88
Cross-walls that divide hyphae into distinct cells
Septation
89
Having no cross walls exept to delimit reproductive structures or aging hyphae (two terms)
Aseptate; coenocytic
90
Clear hyphae
hyaline
91
Sexual spore of Zygomycetes
Zygospore
92
Sexual spore of Ascomycota
Ascospore
93
Sexual Spore of Basidiomycota
Basidiospore
94
Sexual spore of Oomycota
Oospores
95
Where do sexual spores of Oomycota form?
Oogonium; antheridium attached
96
Where do sexual spores of Zygomycota form?
Where gametangia fuse
97
Where do sexual spores of Ascomycota form?
Ascus
98
Where do sexual spore of Basidiomycota form?
Basidium
99
Sexual fruiting body of asocmycota that is open and cup-shaped?
Apothecium
100
Sexual fruiting body of ascomycota that is closed but with a pore (U-shaped)?
Perithecium
101
Sexual fruiting body of ascomycota that is closed?
Cleistothecium
102
Generic name for fruiting body of ascomycota?
Ascocarp
103
Asexual spores of Oomycota? (two options)
Zoospores, Chlamydospores
104
Asexual spores of Zygomycota? (two options)
Sporangiospores (Conidia), Chlamydospores
105
Asexual spores of Ascomycota? (two options)
Conidia, Chlamydospores
106
Asexual spores of Basidiomycota? (two options)
Conidia, Chlamydospores
107
Asexual fruiting body of ascomycota that is flat and bears short conidiophores?
Acervulus
108
Asexual fruiting body of ascomycota that is enclosed and flask shaped?
Pycnidium
109
Asexual fruiting body that is a cushion-shaped pad?
Sporodochium
110
What spores are formed from existing hyphae; thick walled survival spore and occurs in all groups?
Chlamydospores
111
What are a mass of hyphae with the outer layer melanized to make them more durable?
Sclerotia
112
Basidospores are born on ____
Basidium
113
What is the fruiting body of basdiomycota?
Basidiocarp
114
What has hyphae, forms mycelium, has radial growth, produces sexual and asexual spores, and has heterotrophic absorptive nutrition?
Oomycete
115
What component is missing in the cell wall of oomycetes, replaced by cellulose?
Chitin
116
What structure produces Zoospores?
Sporangium on sporangiophore
117
Are oomycetes septate or aseptate?
Aseptate
118
How many flagella do oomycetes have?
2
119
Which primitive fungi have no hyphae and a single flagellum?
Chytrid-like fungi
120
NAME THAT PATHOGEN!
Biotrophic plant pathogen
Holocarpic
Potato Wart; S. endobioticum
Synchytrium
| CHYTRID
121
NAME THAT PATHOGEN!Biotroph
Foliar infection, soil survival
Brown spot of corn
Physoderma
| CHYTRID
122
NAME THAT PATHOGEN!
| O. brassicae, non-pathogenic obligate parasite that takes up and passes on viruses to plants as they swim
Olpidium
| CHYTRID
123
Which fungi is aseptate and has zygospores for sexual spores with asexual spores in sporangia?
Zygomycetes
124
NAME THAT PATHOGEN!
Soft rot of fruit and vegetables
Opportunistic, necrotrophic (commonly post-harvest)
Rhizopus
| ZYGOMYCETES
125
NAME THAT PATHOGEN!
| Fruit rots on peach, pear, tomato, dragon fruit
Gibertella
| ZYGOMYCETES
126
Which fungi has septate hyphae, ascospores in asci, and most fungal plant pathogens reside here?
Ascomycota
127
NAME THAT PATHOGEN!
| Naked asci develop on leaf surface
Taphrina
| ASCOMYCOTA
128
NAME THAT PATHOGEN!
| Opportunistic pathogen, seeds of corn, peanuts, cotton, nut trees; enters through wounds; aflatoxin production
Aspergillus flavus
| ASCOMYCOTA
129
NAME THAT PATHOGEN!
Causes anthracnose, hemibiotroph with 2 phases (bio and necro); wide host range including leaves, fruits, and stems (Coffee berry disease)
Colletotrichum gloeosporioides
| ASCOMYCOTA
130
NAME THAT PATHOGEN!
| Southern corn leaf blight
Cochliobolus heterostrophus
| ASCOMYCOTA
131
NAME THAT PATHOGEN!
Broad host range; saprophytic stage prior to infection; ascospores infect senescing blossoms; no conidia just sclerotia; apothecia formed on sclerotia
Sclerotinia sclerotiorum
| ASCOMYCOTA
132
Which fungi have clamp connections, basidia on basidiocarps and their fruiting bodies are often macroscopic?
Basdiomycota
133
Which subphyla of basidiomycota has may lifestyles and include a variety of pathogens?
Agariomycetes
134
Which subphyla of basidiomycota are all parasitic and smut fungi?
Ustilaginomycotina
135
Which subphyla of basidiomycota consist of almost all parasitic fungi and rust fungi?
Pucciniomycotina
136
NAME THAT PATHOGEN!
| No conidia, profuse sclerotia, no basidiocarps, two types of hyphae (fine and coarse), infrequent sexual stage
Athelia (Sclerotium) rolfsii
| BASIDIOMYCOTA
137
NAME THAT PATHOGEN!
No conidia, rarely basdiospores, have pseudosclerotia; causes many rots especially in seedlings; stem and crown rots, blights, fruit rots
Rhizoctonia
| BASIDIOMYCOTA
138
Obligate biotrophs; specialists in restricted host ranges
Rusts
139
Pathogen strains with identical morphology that attack different host species
forma specialis (f. sp.)
140
Race attacks one or more cultivars (varieties) within host species
Pathogen races
141
Rust whose life cycle requires 2 hosts
Heteroecious
142
Rust whose life cycle is on a single hose
Autoecious
143
Rust with all 5 spore types in its life cycle
macrocyclic
144
Rust lacking urediniospores in its life cycle
demicyclic
145
Rust with only 2 types of spores produced (Basidiospores and teliospores)
microcyclic
146
5 Rust Spores
```
Basidiospores
Spermatia
Aeciospores
Urediniospores
Teliospores
```
147
Basidiospores are produced on ______ and are ____
Basidia, 1n
148
Spermatia are produced on _______ and are __
Spermagonia, 1n
149
Aeciospores are produced on _________ and are _____
Aecia; n+n
150
Urediniospores are produced on ______ and are ____
Uredinia; n+n
151
Teliospores are produced on _________ and are _____
Telia; n+n
152
Look at wheat rust cycle
OK
153
NAME THAT PATHOGEN!
| Wheat rust; heteroecious (barberry, wheat); macrocyclic
Puccinia graminis
154
NAME THAT PATHOGEN!
| Fusiform rust; heteroecious (pine, oak); macrocyclic
Cronartium quercum
155
NAME THAT PATHOGEN!
| Cedar apple rust; heteroecious (cedar, apple); demicyclic
Gymnosporangium
156
NAME THAT PATHOGEN!
| Soybean rust; indefinitely in asexual stage, continuously makes uredospores
Phakopsora meibomiae
157
NAME THAT PATHOGEN!
| Soybean rust; autoecious; microcyclic
Phakopsora pachyrhizi
158
Which term describes a scenario where there are other possibilities, but not required?
Alternative
159
Which term describes a scenario that implies a requirement?
Alternate
160
Oomycete diseases can be _____ or ______
Soilborne or aerial
161
```
Soilborne or Aerial?
Root & crown rots
Damping off
Tuber rots/blights
Fruit decays on or near ground
Seed decays
```
Soilborne
162
```
Soilborne or aerial?
Leaf & Stem blights
Leaf & Fruit Mildews
Fruit decays
Cankers
```
Aerial
163
Soilborne or Aerial Pathogens?
Aphanomyces
Pythium
Phytophthora
Soilborne
164
Soilborne or Aerial Pathogens?
Albugo
Downy Mildews
Phytophthora
Aerial
165
Which term describes when the antheridia and oogonia are on the same mycelium?
Homothallic
166
Which term describes when two opposite mycelia are required?
Heterothallic
167
What term describes when the antheridium is on the side?
Paragynous
168
Which term describes when the antheridium is on both sides?
Amphigynous
169
```
Pythium or Phytophthora?
Which pathogen(s) has/have paragynous antheridium attachment?
```
Pythium or Phytophthora
170
```
Pythium or Phytophthora?
Which pathogen(s) has/have amphigynous antheridium attachment?
```
Phytophthora
171
```
Pythium or Phytophthora?
Which pathogen(s) has/have multiple antheridia?
```
Pythium
172
Pythium or Phytophthora?
| Which pathogen forms a vesicle and then bursts?
Pythium
173
Pythium or Phytophthora?
| Which pathogen has zoospores that swim out individually?
Phytophthora
174
```
Pythium or Phytophthora?
Necrotrophs
Soil inhabitants
Wide Host ranges
Pathogenicity in seeds, seedlings, roots; opportunistic
Many lifestyles
```
Pythium
175
```
Pythium or Phytophthora?
Semi-biotrophs
Soil survivors or aerial
Few with wide host range
All species are plant pathogens
```
Phytophthora
176
Pythium or Phytophthora?
| Pale, water-soaked spots with cholorotic border; rapidly enlarging lesions; fruit discoloration, rot; damaged tubers
Phytophthora
177
What are biotrophs favored by cool, wet weather with abaxial sporangia?
Downy mildews
