Propagation

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Propagation

• Why we propagate plants.

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Why propagate?

• Why propagate?
• 1. Ensure future generations.
• 2. Keeps desired combination of traits alive.
• 3. Do not have to depend on seed germination.
  Some plants have seeds that are hard to
  germinate. Also, do not have to worry about
  pollination.

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Why propagate?

• Possible Problems
• 1. Will not have genetic variation.
• 2. Plants will not be able to change with the
  surroundings.

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Types of Propagation

• Two main types of propagation. They are
• Asexual and sexual.
• Asexual cloning does not require
  fertilization
• 1. Vegetative reproduce by mitosis (each
  daughter cell is an exact replica of its mother
  cell. (cont.)

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Types of Propagation

• Chromosome numbers and composition do not change
  during cell division). Ex stolons and rhizomes.
• 2. Cuttings taking parts of plants and planting
  them
• Stem cuttings
• Leaf cuttings

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Stem Cutting with terminal growing area.
Stem Cutting
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Leaf cutting without petiole.
Leaf cutting with petiole.
Leaf Cuttings
Leaf cutting that has rooted. Used leaf with
petiole.
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Leaf Cutting
Leaf cutting with the petiole attached. Placed
in water and will result in roots being formed.
Leaf cutting with petiole attached but placed in
soil. This will be the result.
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Asexual Cuttings

• Stem cuttings
• Hardwood
• Semi-hardwood
• Soft wood
• Herbaceous
• Leaf cuttings
• Leaf-bud cuttings
• Root Cuttings

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Stem cutting showing an adventitious bud
starting. Begonia plant.
Stem cutting with an auxiliary bud attached.
Stem Cuttings
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Leaf Bud Propagation
For this type of propagation, you use a leaf and
the axil of the leaf along with a portion of the
stem. Place all of this into a medium and let
grow. Type of plants you can use this on are
clematis, grape ivy, dracaena, camellia, jade
plant and rhododendron.
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Asexual Cuttings

• 3. Grafting using woody stems
• Why do we graft?
• Things to remember when grafting.

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Asexual Cuttings

• 3. Grafting when grafting, you use some part of
  the woody stem. There are many types of grafts.
  The following pictures show a procedure called
  whip grafting.

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Step 2 - Tools
Step 3 - Cutting stem to make area for grafting.
Step 1 -Selection
Whip Grafting
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Step 5 Adding the cut down through the middle.
Step 4 - Showing how to make the cut.
Step 6 Making the cut on the grafting material.
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Step 7 Making incision into the graft.
Step 8 Putting the two grafts together.
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Step 9 Wrapping the graft.
Step 10 Finished product.
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Propagation Methods

• 4. Budding inserting bud into existing wood
• 5. Layering taking a stem and promoting root
  growth.

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Layering Simple or mound
Layering taking a branch and placing it on the
soil.
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Removing epidermis for layering.
Packing moss around area to provide moisture.
Wrap in saran wrap to keep moisture in.
Air Layering
Removing saran wrap to see new roots and bud.
New bud with roots.
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Separation Method

• 7. Separation you take mature plants that were
  stolons or offspring from a parent plant and
  separate.

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Runners

• 6. Runners stems that run along the top of the
  ground. They root at the node.

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Stolons Parent plant puts out runners and each
node a new plant forms along with roots.
Runners or Stolons
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Separation of runner from parent.
Separation Method
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Division

• 8. Division taking tubers, roots, bulbs, or
  corms and dividing them.

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Stem Tubers potato eyes become plants.
Stem Tubers
Division
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Division
Corms roots develop around the edge in a
circle. The enlarged area is the stem and the
leaf sprouts in the concave area on top. Each one
of these leaves will become a corm next year.
Crocus and glads are examples.
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Suckering

• Suckers growth from the root or crown area.
  Would use division here because of the roots.

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Suckering where plants are produced from roots.
Raspberries, willows and dog woods are examples.
Suckering
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Tissue Cultures

• 9. Micro propagation Tissue cultures
• Tissue cultures are taking a small part of a leaf
  or stem (usually cut into small pieces), placing
  them in a petri dish that contains agar (medium
  that has nutrients added to it).

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Micro propagation
Micro propagation using a part of the plant
such as a piece of the leaf (African violet) and
placing it in a Petri dish that has agar in it.
Roots form from this piece of leaf.
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Factors Influencing Rooting

• Factors influencing the rooting of cuttings.
• 1. Source of cutting material.
• Young, non flowering plants only a few years away
  from a germinated seed is best.
• 2. Time of year the cutting material is taken.
• Woody perennial (means grows for a number of
  years)- anytime

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Factors Influencing Rooting

• Hardwood cuttings late winter
• Softwood cuttings spring after growth reaches
  4-6.
• Semi-hardwood cuttings midsummer
• Herbaceous anytime of the year (do not develop
  woody tissues).

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Factors Influencing Rooting

• 3. Treatment of cuttings with Auxins (natural
  plant hormones)
• IAA (indoleacetic acid), IBA (indolebutric acid)
  or NAA (naphthalenoeacetic acid
• All stimulate root growth

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Factors Influencing Rooting

• 4. Misting needed in herbaceous cuttings. Need
  to keep hydrated so will not dry out.
• Mist the plant then cover with plastic cover.
  Keeps moisture in.
• Can also have an automated mist system.
• 5. Bottom heat helps force rooting by
  stimulating the root to grow.

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Sexual Propagation

• Seed formation is an example of sexual
  propagation
• Get genetic diversity from this form
• Where you have a male and a female and have cross
  pollination for fertilization between the two to
  form the seed.
• Meiosis another form of sexual propagation

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Sexual Propagation

• In meiosis the number of chromosomes in the cells
  is reduced by half to form the male sperm cell
  and the female egg. The egg and sperm combine
  during fertilization in the ovule to form the
  zygote (fruit) that develops into the embryo
  (seed).
• California desert plant called Machaeranthera
  gracilis example

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Seed Germination

• Monocot Seed
• The seed imbibes (absorbs) water from the soil
• Emergence of radicle (primary root) and the
  plumule (primary shoot)
• These form the primary parts of the plant.

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Monocot Seed
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Dicot Seed

• Dicot Seed
• Seed imbibes water from soil and swells.
• Radicle emerges and grows downward.
• Hook of the bean (hypocotyl) emerges from soil,
  carrying the two cotyledons (leaves) with it.

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Dicot Seed
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Environmental Factors Influencing Seed Germination

• Adequate moisture in the soil.
• Proper temperature cold versus warm
• Good aeration of soil.
• Light (in some cases)
• Freedom from pathogenic organisms. Damping off.
• Freedom from toxic amounts of salts.

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