1. Chap 12. Plant Propagation
I. Three Methods of Plant Propagation
Sexual Propagation (Seed Propagation)
Asexual Propagation (Vegetative Propagation)
Micropropagation (Tissue Culture)

2. Mostly in Western States
II. Sexual Propagation
Seed production
Mostly in Western States
- California, Oregon, Washington, Idaho
- Low humidity (less fungal, bacterial diseases)
- Mild temperature (good for flowering, seed set)
- Even distribution of rainfall throughout year
- Isolated from major production areas
Hybrid Seed Production
- Use of male sterility (US production)
- Hand pollination (Developing countries)
Labor Intensive Operation
- Pollination
- Harvesting, cleaning, and handling

3. 2. Seed Storage Optimum condition for seed storage
Low temperature (0-32 oF)
Low humidity (less than 10% RH)
Practical storage conditions
32-50 oF, 50-65% RH
Seed longevity varies by species
Most annual flowers last 1-2 years
Woody plants 5-20 years
Lotus seed known to last over 1000 years
Permanent storage at cryogenic temperature(-196 oC)

4. 3. Seed Germination Seed Germination Test Enhancement of % Germination
Seed viability
Determined by percent germination (100 seed lots)
Tetrazolium (TTC) test to find tissue viability
Enhancement of % Germination
Seed quality and storage conditions
Seed priming to enhance germination vigor and uniformity

5. Seed Priming
A process of prehydrating and redrying seeds to enhance their subsequent germination performance
Used for flower and vegetable seeds for uniform and vigorous germination
Us e of osmotic solution

6. Breaking Seed Dormancy
Scarification
Overcomes physical seed dormancy
(Seed coat is impermeable to water)
Three methods
Mechanical abrasion
Hot water ( oF)
Acid treatment (concentrated sulfuric acid)
Stratification
Overcomes physiological seed dormancy
(Embryo dormancy, internal dormancy)
Moistened, cold storage
Storage at 32 oF for 1-9 months)
Some species may require warm stratification
Viburnum, Redbud

7. Two Different Types of Germination
Epigeous Germination
Cotyledons are exposed above ground
Epicotyl and hypocotyls are also visible
Cherry, soybean, radish
Hypogeous Germination
Cotyledons are buried in the ground
Only epicotyl are visible
Peach, pea, apricot

8. Germination of Angiosperm Seeds

9. Embryo Culture Used in abortive inter-specific crosses (i.e., potato)
Immature zygotic embryos are excised and cultured in vitro to obtain viable seeds
Used in abortive inter-specific crosses (i.e., potato)
Used for embryos lacking endosperm (i.e., orchids)
Double fertilization
In-ovulo
Embryo culture
Seed germination

10. 4. Field Establishment Direct Seeding Transplanting
Use of pelletized seeds
Mechanical planting
Transplanting
Mechanical transplanting
Use of fluid drilling
Plug-grown seedlings
High value vegetable crops
Lettuce, cabbage, celery (i.e., California, Arizona)

11. Seedling Production in Greenhouse

12. II. Vegetative Propagation
Use of Apomictic Seeds
Use of Specialized Vegetative Structures
Adventitious Root Induction (Cuttings)
Layering
Grafting

13. a. Use of Apomictic Seeds
Apomixis = Development of seeds from maternal tissue inside ovule
Some apomictic seeds are formed from megaspore mother cells
Apomictic seeds produce plants that are genetically identical as maternal plants
Examples: Mango, Kentucky bluegrass, Citrus

14. How is Apomictic Seed Formed?
Asexual seed formation from maternal tissues around zygotic embryo inside an ovule
Apomictic seeds can be formed from nucellar tissues, egg mother cell, flower heads (bulbils)
Found in Kentucky bluegrass, dandelion, citrus, Alliums
Nucellar embryos in Citrus

15. b. Specialized Vegetative Structures
Runners (Stolons)
Bulbs
Corms
Rhizomes
Off-Shoots
Stem Tubers
Tuberous Roots
Root Suckers

16. Runners (Stolons) Above-ground running stems
New plants are formed on each node
Examples: Strawberry, Spider Plant, Buffalograss
Strawberry
Buffalograss

17. Bulbs
A specialized underground organ consisting of a basal plate, growing points, flower primordia, and fleshy scales
Found in monocots
Tunicate bulbs - Onion, tulip, garlic, hyacinth
Non-tunicate bulbs – Easter lily, Oriental lily
Bulblets, bulbils, stem bulblets

18. Scaly Bulbs: Easter Lily

19. Corms: Gladiolus

20. Rhizomes Laterally grown underground stems
Iris, ginger, lily of the valley, orchid

21. Offshoots
Lateral shoots, often with roots at the base, produced on main stems which can be separated and grown as independent plants
Examples: Pineapple (slip), dendrobium, cymbidium

22. Stem Tuber Examples: potato, caladium, Jerusalem artichoke
Tuber is a swollen, modified stem structure that functions as an underground storage organ
Examples: potato, caladium, Jerusalem artichoke
Use of eyes in potato propagation

23. Tuberous Roots

24. b. Cutting Propagation
Detached stems and roots are used to induce adventitious roots or shoots
Woody Plants
Hardwood cuttings
Softwood cuttings
Semi-hardwood cuttings
Single-node cuttings
Root Cuttings
Problem with phenotype conversion in chimeric plants

25. Influence of IBA on Rooting-Cordia parvifolia
1-Control, 2-50% ethanol, ppm, ppm, ppm, ppm, ppm, ppm, ppm IBA

26. Cutting Propagation in Jojoba
Regular Stem Cuttings
Use 4-5 nodes
Semi-hardwood cuttings
Single Node Cuttings
Double-eye single node cuttings
Single-eye single node cuttings

27. Single Node Cuttings of JojobaSE DE
5-node SE DE

28. Softwood Cuttings-Peach

29. Hardwood and Semi-hardwood Cuttings3 1 2 5 4 6
1-Stock plant nursery, 2-making cuttings, 3-bundles of cuttings, 4-IBA treatment, 5-rooting in artificial mix, 6-outdoor misting system for rooting

30. Pauk Ecke’s Poinsettia Greenhouse

31. Herbaceous Cuttings - Carnation

32. Leaf Cuttings-African Violet, Piggyback Plant

33. Chimeras Chimera (Greek Word)
A plant that is composed of tissues of more than one genotype
Chimera (Greek Word)
A mythological monster, having a lion’s head, a goat’s body and a serpent’s tail
Chimera
Periclinal Chimera

34. Three Types of Chimeras

35. Examples of Chimeric Plants
Chrysanthemum
Rose

36. Propagation by Grafting
Requirements for Success
Compatibility between stock and scion
Alignment of cambium layers
Prompt handling
Grafting Methods
Cleft grafts
Whip-and-Tongue
Side grafts
Budding
Inarching
Bridge Grafts
Topworking

37. Use of Herbaceous Grafting
Virus Indexing
Synthetic Plants
Construction of Genetic Chimeras
Improved Crop Performance
Research in Plant Physiology
Enhancement of Esthetic Value

38. Cucurbits (watermelons, melons, cucumbers, squashes, etc.)
Various grafting methods in vegetables with or without rootstock root systems
Solanaceous crops (tomatoes, peppers, eggplants, paprika, etc.)

39. Chinese cabbage/Radish
Tomato/eggplant
Eggplant/potato

40. Robotic Grafting Machine

41. Hylocereus trigonus, the most popular rootstock for cactus grafting
Cut
Diameter of scion: 10 mm.
Vascular bundle
※ After placing the scion on the top of rootstock to match the vascular bundle, thread or clips are used to hold the position.
* Standard rootstock length : 9 cm long
* Diameter of rootstock: 30~ 35 mm
Hylocereus trigonus, the most popular rootstock for cactus grafting

42. G F H