1. Plant Propagation ASEXUAL PROPAGATION
Level 2 Horticulture Science
Plant Propagation ASEXUAL PROPAGATION
US 20556
10 Credits – Internal Assessment

2. Contents Asexual vs sexual Propagation Asexual propagation (overview)
Division
Layering
Tissue culture
Cuttings
Budding and Grafting
Plant Breeders Rights

3. Propagation:
DEFN:
Plant propagation is the process of creating new plants
Plant propagation can also refer to the artificial or natural dispersal of plants.
Types of Propagation:
Things that are not examples of Propagation

4. Asexual and Sexual Propagation
Asexual Propagation - using one parent plant to produce a new individual that is a clone (genetically identical)
Key words: offspring, new individuals, parent plant(s),
Sexual Propagation – recombination of the genes to produce a new individual that is a genetically different
(also known as sexual reproduction)
In Angiosperms -This always involves flowers and always results in seed.
In Gymnosperms/ ferns and Moses this results in spores
Question – if a plant self pollinates is it sexual or asexual propagation?

5. Examples of Propagation Techniques
Sexual
Asexual
Seed
Layering
Tissue Culture
Grafting
Budding
Stem Cuttings
Leaf cuttings
Root Cuttings
Bulbs
Corms
Runner
Rhizomes
Crown division
Stolons

6. Asexual Propagation (outline)
We will be investigating 5 methods of asex prop.
Cuttings
Grafting and Budding
Division
Layering
Tissue Culture
To begin to understand asexual propagation (AsexP) we need to understand meristematic cells

7. Parts of a plant

8. Importance of Meristematic cells
Meristematic cells – plant cells that are capable of dividing to create new plant cells that are unspecialised
Cambium layer – contains the meristematic cells
Unspeciallised cells are able to turn into any type of plant cells.... Eg
xylem
Phloem
Epidermal
Mesophyll

9. Location of cambium layer

12. Division
Plant structures

13. Cuttings Leaf Stem Hardwood Semi-hardwood Softwood 4 types of cuttings
Stem cuttings are the second most widely used form of propagation in horticulture.
(Number one is seed)

14. Semi- hardwood cuttings of Forsythia
Leaf cuttings of petunias
Hardwood cuttings of grape vines
Tip (softwood) cuttings of Hydrangeas

15. Importance of Meristematic cells
Meristematic cells – plant cells that are capable of dividing to create new plant cells that are unspecialised
Cambium layer – contains the meristematic cells
Unspeciallised cells are able to turn into any type of plant cells.... Eg
xylem
Phloem
Epidermal
Mesophyll

16. Location of cambium layer

19. How does crown tissue work.
The crown area of a plant contains both stem and root tissue and corresponding cells such as xylem, phloem and epidermis
Theses cells are already speciallised and will go onto create more of the same specialised cells.
Crown of rhubarb plants

20. Seed sowing To understand seed sowing technique we will be looking at:
Seed structure
Germination
Respiration
Seed requirements
Seed Dormancy
Seed Sowing Menu

21. Seed sowing – seed structure
Three parts to a seed
Seed coat
Endosperm
Embryo
‘A seed is a plant in a box with it’s lunch’
Seed Sowing Menu

22. Seed sowing – seed structure
Seed coat -the outer covering of a seed helps protect the embryo from injury and drying out. Seed coats can be thin and soft as in beans or thick and hard as in walnuts or coconut seeds.
Endosperm, a temporary food supply, is packed around the embryo in the form of special leaves called cotyledons or seed leaves. These are often the first parts visible when the seed germinates.
Embryo – the ‘baby’ plant.
Seed Sowing Menu

23. Two different situations:
Cotyledon(s) appear above ground as first leaves (seed leaves)
Cotyledon(s) remain below the ground

24. Seed sowing – Seed Structure
There are two types of plants that produce seeds:
Monocotyledons
and Dicotyledons
Seed Sowing Menu

25. Seed Structure
Seed Sowing Menu

26. Germination Starts when the seed begins to absorb water
Ends when the new plant is able to get all its’ energy from photosynthesis.

27. Germination – the process
The seed absorbs water until it swells and smoothens its exterior wrinkles.
Swelling continues until the coat of the seed bursts open.
Food stored in cotyledons or endosperm soaks up water and soluble substances dissolve in it.
Respiration begins thus energy and raw materials are supplied by food for cell division and growth.
A radical appears first and then a pumule.

28. Respiration
During respiration (in plants and animals) energy is released from sugar (glucose) by a series of chemical reactions. The sugar is broken down into carbon dioxide and water in a process which uses oxygen.

29. Respiration in seeds
INPUTS OUTPUTS

30. Seed requirements List the inputs all seed require to germinate
Match your list to the following.
Allows seed to swell and break seed coat
Required for respiration
Speeds up the various chemical processes

31. Seed dormancy
Dormant seeds are seeds that are still alive but when the seed is supplied all that it needs to germinate, - it doesn't.
The seed is asleep, waiting for the proper time to awaken.
Seed dormancy aids a species' survival by delaying germination so that 'overall germination' is dispersed over time.

32. Seed Storage Germination needs water. warmth and oxygen
Seed storage needs (the opposite)
Cool and dry!
Why can we not store seeds in a oxygen free environment?

33. Seed Sowing Summary
Seeds don’t get re-assessment opportunities. Once they begin to germinate they either survive or die.
Seeds need the WOW factor to survive (water oxygen, warmth). Soil, light, CO2 are only for ‘grown-up’ seeds
A seed is a plant in a box with it’s lunch – but no dinner – if a seed is in the packet too long it will run out of lunch and die.

34. End – Seed Sowing
Back to Main menu

35. cuttings
Stem cuttings are the second most widely used form of propagation in horticulture.
(Number one is seed)

36. Semi- hardwood cuttings of Forsythia
Leaf cuttings of petunias
Hardwood cuttings of grape vines
Tip (softwood) cuttings of Hydrangeas

38. Division
Examples of Asexual
Examples of Sexual

39. Grafting
Examples of Asexual
Examples of Sexual

40. Layering
Both air layering and ground layering are used in commercial horticulture to produce cloned plants.
Layering is more difficult than taking cuttings but has the advantage that the plant is still attached to the parent plant receiving water and nutrients.
Air layering is often used to fast track the creation of a bonsi
The rooting process in layering may take form a few weeks to several years depending on the plant being propagated

41. Air layering
Air Layering is generally used when other forms of propagation are difficult.
Two techniques are shown – but both expose the cambium layer
You tube – Creating a bonsi

42. Ground layering
Ground layering is often used for brambles (cane berries such as raspberries etc.)
Also used for apples (although no longer commonly used)
Compound trench layering
Simple ground layering