1. Seed Characteristics
Plant Propagation

2. 3 Basic Parts
Embryo
Food Storage Tissues
Coverings

3. Embryo Living part of the seed.
Produced by the fusion of male and female gametes.

4. Young Seedling
Epicotyl: means “above the cotyledons”. It becomes the above-ground shoot.
Hypocotyl: means “below the cotyledons”. It becomes the below-ground root system.

5. Epigeous vs. Hypogeous Germination
Epigeous Germination
Hypogeous Germination
Cotyledons
First true leaves

6. Food Storage Tissues
Endosperm in monocots.
Cotyledons in dicots.

7. Coverings Seed coat ( formed from integuments).
In some cases the Pericarp (ovary wall).

8. Sunflower Seed

9. Germination Requirements of Seed
Moisture
Favorable temperatures
Oxygen

10. Light and Seed Germination
May be required for germination in some species:
Small-seeded annual plants
Photo-dormant weed seeds

11. Seed Dormancy
A seed is said to be dormant when it is unable to germinate even though the proper conditions for germination are all present.

12. Viable vs. Non-viable Seed
Viable: the embryo is alive and capable of germinating.
Non-viable: the embryo is dead and cannot germinate.

13. Viability Tests #1 Place the seed in a bucket of water.
#2 Tetrazolium test.
#3 Cut test.
#4 Germination test.

14. Seeds Treated with Tetrazolium

15. Stages of Seed Germination
#1 Activation
#2 Nutrient digestion and translocation
#3 Seedling growth

16. Activation Imbibition of water – physical process
Increased enzyme activity
Cell elongation/enlargement
Radicle emergence

17. Radicle Emergence in Corn
Corn Seed
Radicle

18. Nutrient Digestion and Translocation
Stored food converted from starches to simpler forms (sugars).
Sugars absorbed by cotyledons and translocated to the embryo.

19. Seedling Growth Epicotyl emergence.
Continued development of the radicle.

20. Seed Provenance
Refers to the geographical region from which the seed is collected.
Cold hardiness
Growth rate
Drought tolerance, etc…
USDA Forest Service “Super Trees”.

21. The End