Lecture 3 and 4: Propagation by Cuttings

Question 1

Benefits of cuttings

Answer 1

1. more efficient use of space
2. least expensive way of cloning plants
3. more uniform crop

Question 2

Topophysis

Answer 2

the position on the stock plant impacts the growth orientation of the propagule

Question 3

Dedifferentiation

Answer 3

the ability of previously developed, differentiated cells to initiate cell division and form new meristematic regions

Question 4

Necrotic plate

Answer 4

protective barrier from drying and from potential invading pathogens

Question 5

callus

Answer 5

hard formation of tissue

Question 6

4 Stages of Adventitious Root Formation

Answer 6

1. Dedifferentiation of cells
2. Formation of root initials
3. Development of root initials into organized root primordia
4. Growth and emergence of the root primordia outward through stem tisssue

Question 7

What time of year should the cutting be taken?

Answer 7

When a bud begins growth in the spring the shoot is immature and there is very little secondary growth

Question 8

Deciduous plant are most often propagated by…

Answer 8

softwood cuttings

Question 9

Broad-leaved evergreems usually root best as…

Answer 9

semi hardwood cuttings

Question 10

Conifers root best as…

Answer 10

hardwood cuttings

Question 11

Softwood stage of growth

Answer 11

from bud break until about the time the shoot stops elongating

Question 12

Semi-hardwood stage of growth

Answer 12

After shoot growth stops, secondary development continues and by early-fall, the plant is preparing for dormancy

Question 13

Hardwood stage of growth

Answer 13

once dormancy sets in, the shoots are in the hardwood stage of growth

Question 14

Transpiration

Answer 14

the process that drives water movement in a plant from roots to shoots

Question 15

How can water loss be managed?

Answer 15

1. Mist systems
2. Fog
3. Low temp

Question 16

How does mist manage water loss?

Answer 16

mist settles out of the air onto the cuttings and the media which limits transpiration

Question 17

How does fog manage water loss?

Answer 17

fog reduces the oppurtunities for evaporative cooling

Question 18

Water logging

Answer 18

can be caused by using a media whose texture is too fine or by over misting

Question 19

Auxins

Answer 19

1. the only plant hormone/PGR that reliably induce rooting
2. active ingredient in most rooting compounds in which cuttings are dipped during vegetative production

Question 20

Indoleacetic Acid(IAA)

Answer 20

1. naturally created in leaves and moved down stem to roots
2. limited use for rooting since plants and microbes easily break it down

Question 21

Indole butyric acid(IBA)

Answer 21

1. mimic auxin
2. can be applied in a liquid or power form
3. has to dissolve and then carried into cutting

Question 22

Naphthaleneaetic acid

Answer 22

-most commonly used PGR after IBA
-Dip n Grow

Question 23

Etoliation

Answer 23

buds break dormancy and grow in the dark

Question 24

Phototropism

Answer 24

bending toward a light source

Question 25

Geotropism

Answer 25

downward root growth in response to gravity

Question 26

Gibberellins

Answer 26

1. stimulates cell division and elongation
2. involved in seed dormancy and rate of germination
3. inhibits bud, shoot, and root formation

Question 27

Cytokinins

Answer 27

1. stimulates and plays a regulatory roll in cell division
2. included in sterile media when growing plants in tissue culture to initiate shoot formation

Question 28

Ethylene

Answer 28

1.only found in gaseous form
2. governs the development of laves, flowers, and fruits
3. induces ripening

Question 29

High cytokinins

Answer 29

low auxin ratio stimulates adventitious bud formation and overcomes apical dominance

Question 30

Abscisic acid(ABA)

Answer 30

1. regulates stomata closure
2. induces germination

Question 31

Epinasty

Answer 31

when ethylene damage have leaves that are curled down and stems that are twisted

Question 32

1-MCP

Answer 32

is a gaseous ethylene action inhibitor