1. Plant Reproduction

2. Terms
Propagation/Reproduction –The process of increasing numbers of a species, or perpetuating a species
Sexual Reproduction – The union of an egg (ovule) and sperm (pollen), resulting in a seed. 2 parents creating a 3rd individual is referred to as sexual propagation
Asexual Reproduction/Vegetative – Utilizing a part or parts of 1 parent plant. The new plant is a clone (exact duplication) of its parent
Hybrid Vigor – Refers to the tendency of hybrid plants to be stronger and survive better than plants of a pure variety

3. Sexual/Asexual Comparison
Sexual Propagation Advantages
Less Expensive
Many parts can be produced quickly
Crosses result in hybrid vigor
Avoids passing on some diseases
Asexual Propagation Advantages
Less time is required to produce a salable (fit for sale) plant
Plants are genetically identical
The only way to produce some plant varieties

4. Parts of a Seed
Embryo- The young multi-cellular organism before it emerges from the seed
Endosperm- A source of stored food, consisting primarily of starches
Seed Coat- Consists of 1 or more protective layers that encase the seed
Cotyledon- A seed leaf that stores food in the form of starch and protein for use by the embryo
Epicotyl- The portion of the embryonic stem above the point at which the stem is attached to the cotyledon(s)

5. Germination Germination – A seed sprouting or starting to grow
Dormant – Resting stage, no active growth
To germinate the seed must be placed in certain favorable conditions
The 4 environmental factors that must be right for effective germination are water, air, light, and temperature

6. Germination-Water
Imbibition (the absorption of water) is the 1st step in the germination process
It allows the seed to fill all of its cells with water
A good germination medium is important – (Too dry – death of the embryo) (Too wet – Rotting)
In some species the seed coat is very hard and water cannot penetrate the endosperm. The seed can be scarified (nicking the seed coat with a knife or file) to remedy this.
Also can soak the seed in concentrated sulfuric acid or soaking the seeds in hot water for 12 to 24 hours

7. Germination - Air
Viable seed is alive and capable of germinating, respiration takes place in all viable seed
Oxygen is required
As germination starts, the respiration rate increases
Germination will be reduced or inhibited if oxygen supply is limited or reduced

8. Germination - Light
Some seeds are stimulated to grow by light and some are inhibited by the presence of light
Many agronomic crops do not require light
Many ornamental bedding plants are more likely to require light for germination. Ex – Impatiens, Petunia

9. Germination-Temperature
Heat is important for germination and effects the germination rate
The only way to control field crops is to plant when the ground is warm
A knowledge of the heat requirement is required in plants grown in greenhouses

10. Monocot Germination

11. Dicot Germination

12. Asexual Propagation Stem Cuttings
Stem Tip Cuttings
Stem Section Cuttings
Cane Cuttings
Heel Cuttings
Single-Eye Cuttings
Double-Eye Cuttings

13. Asexual Propagation Leaf-Type Cuttings
Leaf Cuttings
Leaf Petiole Cuttings
Leaf Section Cuttings
Split-Vein Cuttings

14. Asexual Propagation Root Cuttings

15. Asexual Propagation Simple Layering

16. Asexual Propagation Tip Layering

17. Asexual Propagation Air Layering

18. Asexual Propagation Division

19. Asexual Propagation Grafting= T-Budding

20. Asexual Propagation Tissue Culture