Final part 2

Question 1

Haustoria-

Answer 1

Specialized absorption structures produced on parasitic plants

Question 2

Epiphytes:

Answer 2

Physiologically dependent, no chlorophyll or leaves. Ex: Spanish moss

Question 3

Holoparasites: .

Answer 3

Dependent entirely on host; biotroph. Small leaves, scales. Contains chlorophyll.

Question 4

Hemiparasites: Dependent of host for water and minerals. Contains chlorophyll and leaves.

Answer 4

Dependent of host for water and minerals. Contains chlorophyll and leaves.

Question 5

4 major groups of parasitic plants:

Answer 5

1. Broomrapes, holoparasite. Host: sunflower.
2. Dodder, holoparasite. Host: wide range of perennials.
3. Witchweeds, hemiparasite. Host: corn.
4. Mistletoe, hemiparasite. Leafy Host: Hardwoods. Dwarf host: conifers

Question 6

How are parasitic plants managed?

Answer 6

Protection: Provide adequate water and nutrients for host plant.
Avoidance: Choose planting sites where chance of parasite is low.
Exclusion: Impose quarantines.
Eradication: Herbicides, selective pruning, hand-pulling plants.

Question 7

Trap crops:

Answer 7

: (example) host crop is planted to stimulate seed germination then plowed before weed germinate.

Question 8

how is witch weed managed?

Answer 8

trap crops

Question 9

Disease:

Answer 9

injurious and progressive; gets worse over time.

Question 10

injury:

Answer 10

damage caused by transitory interaction with insect, chemical, or unfavorable environmental conditions

Question 11

Winter burn:

Answer 11

 Or desiccation, rust occurring of evergreens caused by low soil moisture, freezing temperatures and harsh winds

Question 12

Sunscald:

Answer 12

Winter time injury to tree trunks, caused by the sun—deciduous

Question 13

Etiolation:

Answer 13

plants grown in the absence of light.

Question 14

Which minerals are most likely to be toxic?

Answer 14

Boron, Manganese, Copper

Question 15

What is acid rain/precipitation?

Answer 15

Air pollutants, such as sulfur and nitrogen oxides, react with H2O to form sulfuric and nitric acids

Question 16

How does acid rain affect plant growth?

Answer 16

Causes chlorosis, defoliation, and stunting of trees- forest decline.

Question 17

What causes injury due to herbicides?

Answer 17

Misapplication, spray drift, movement of water, and chemical residues.

Question 18

List three other causes of abiotic diseases

Answer 18

Excessive or deep cultivation, construction, girdling of trees by fence wire

Question 19

Immunity –

Answer 19

Freedom from attack and injury by pathogen

Question 20

Tolerance –

Answer 20

Ability of plant to survive effects of disease without suffering serious injury or great crop loss

Question 21

Escape –

Answer 21

Apparent resistance

Question 22

Constitutive (passive) defenses –

Answer 22

mechanisms are in place whether or not the pathogen is present; waxy cuticles

Question 23

Induced (active) defenses –

Answer 23

mechanisms develop in response to attempted entry and/or establishment of pathogen; cork layers

Question 24

o Tyloses –

Answer 24

form in xylem
Outgrowth of adjacent protoplasts
Plug xylem vessels and stop movement of pathogen

Question 25

which types of pathogenss have all 3 types of variations?

Answer 25

parasitic plants
fungi
nematodes

Question 26

Which types of pathogens have only mutation as a source of genetic variation?

Answer 26

bacteria and viruses

Question 27

Pathogenicity –

Answer 27

ability of pathogen to cause disease in a plant species (virulence)

Question 28

What is the gene-for-gene hypothesis?

Answer 28

“For each gene in the host capable of mutating to give resistance, there exists a gene in the pathogen capable of mutating to overcome that resistance.”

Question 29

Mass Selection:

Answer 29

slow improvements, select seed of highly resistant plants in a field with natural disease infection.

Question 30

Pure line or pedigree selection:

Answer 30

select highly resistant plants, propagate progency of each plant separately.

Question 31

Recurrent selection or backcrossing:

Answer 31

desirable but susceptible cultivar is crossed with a resistant cultivar or wild relative.

Question 32

Production of Hybrids: Cross two lines containing different genes for resistance.

Answer 32

Cross two lines containing different genes for resistance.

Question 33

Marker-assisted selection:

Answer 33

Used with traditional breeding methods, use molecular biology to identify R genes on chromosomes

Question 34

Genetic engineering:

Answer 34

Transfer of specific genes b/t organisms using enzymes and laboratory techniques instead of traditional biological crossing.

Question 35

Name three methods of exclusion.

Answer 35

Quarantines, Pathogen-free seed, and pathogen-free propagative parts

Question 36

Hypovirulence:

Answer 36

using a virus that infects pathogen, reducing its

Question 37

Name four methods of reducing leaf wetness.

Answer 37

Fans, improve soil drainage, row orientation

Question 38

Cross-protection:

Answer 38

inoculate with a mild strain of virus to protect against infection

Question 39

inorganic fungicides are strictly ?

Answer 39

protective

Question 40

2 common fungicides:

Answer 40

Captan and Bravo

Question 41

Amphimobile:

Answer 41

phloem-mobile; move both upward and downward within plant.

Question 42

What does FRAC stand for?

Answer 42

Fungicide Resistance Action Committee

Question 43

What types of pathogens are killed by antibiotics?

Answer 43

Bacteria, mollicutes and some fungi.

Question 44

Define integrated pest management

Answer 44

Combination of cultural, biological, physical and chemical controls.