Module 3: Seed Propagation

Question 1

What are the three essential parts of the seed?

Answer 1

Embryo
Cotyledons and endosperm
Seed covering

Question 2

What is the hilum?

Answer 2

Scar where the seed was attached to the fruit

Question 3

What is the micropyle?

Answer 3

Small opening

Question 4

What is the raphe?

Answer 4

Ridge on the seed

Question 5

What does the embryo of a dicot seed consist of?

Answer 5

Epicotyl, hypocotyl, radicle and 2 cotyledons

Question 6

What is a plumule?

Answer 6

Name given to the primary shoot

Question 7

What is the sequence of events involved in germination?

Answer 7

Imbibition of water by the seed
Activation of hormones and enzymes
Embryonic growth and development

Question 8

What is in a monocot seed?

Answer 8

1 cotyledon in the seed
Endosperm as a second food storage structure

Question 9

What are the sequences of events involved in monocot seed germination?

Answer 9

Emergency of the radicle and plumule

Question 10

What is the coleoptile?

Answer 10

Membrane covering the plumule, protecting it as it emerges from the soil

Question 11

What environmental factors can affect seed germination?

Answer 11

Adequate moisture
Proper temperature
Good aeration
Light (some cases)
Freedom from pathogens
Freedom from excessive salt

Question 12

What is seed production?

Answer 12

To maintain a cultivar through seed propagation.

Very important to control the seed source

Question 13

Why is it beneficial to have self-pollinated species?

Answer 13

Seed purity is generally assured

Question 14

What are the cons of having cross-pollinated species?

Answer 14

Need to be separated from other plants to avoid pollen contamination

Question 15

What does Canadian Seed Growers’ Association do?

Answer 15

Determines purity standards and is responsible for the certification of most agricultural crops

Question 16

What is an F1 Hybrid seed?

Answer 16

Crossing of two inbred lines may produce an F1 hybrid seed with increased plant vigor

Question 17

Where does F1 hybrid seed crossing occur?

Answer 17

Field crops, vegetables, herbaceous bedding plants

Question 18

How does humidity and temperature affect seed storage?

Answer 18

Seeds in sealed containers at low temps ( 0-4C) and humidity of 15% will last longer compared to seeds at room temperature in a humid environment

Question 19

How long will willow, maple and elm seeds remain viable?

Answer 19

Few days to months

Question 20

How long will legume seeds remain viable?

Answer 20

Several years

Question 21

What are the different seed viability tests you can conduct?

Answer 21

Cut test (cut to see if there’s an embryo)

Float test (floating seeds don’t have embryos)

Xray photographs

Germination test: for seeds with no dormancy issues, germination % can be calculated

Tetrazolium test: tetrazolium turns red when it comes in contact with respiring tissue

Excised embryo test

Question 22

Why is seed dormancy a survival mechanism?

Answer 22

Important for woody perennials to prevent germination of seeds all at once or during unsuitable periods of time

Question 23

What is seed coat dormancy?

Answer 23

The seed coat is impermeable to water and gases or has high resistance to embryo expansion

Question 24

How can you artificially overcome seed coat dormancy?

Answer 24

Scarification (scratch seed surface)

Heat treatment (boiling water)

Acid scarification (concentrated sulfuric acid)

Question 25

What is embryo dormancy?

Answer 25

Physiological conditions in the embryo that prevent active growth

Question 26

How can you overcome embryo dormancy?

Answer 26

Stratification (moist chilling treatment)

• Moisture, 1-7C, oxygen, time