Download Propagation

Propagation
Why we propagate plants.
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.
Why propagate?

Possible Problems
1. Will not have genetic variation.
2. Plants will not be able to change with
the surroundings.
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 it’s mother cell. (cont.)
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
Stem Cutting with terminal growing area.
Stem Cutting
Leaf cutting
with petiole.
Leaf cutting
without
petiole.
Leaf Cuttings
Leaf cutting that has rooted. Used leaf with petiole.
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.
Asexual Cuttings
Stem
cuttings
 Hardwood
 Semi-hardwood
 Soft wood
 Herbaceous
Leaf cuttings
 Leaf-bud cuttings
Root Cuttings
Stem cutting showing an
adventitious bud starting. Begonia
plant.
Stem cutting with an
auxiliary bud attached.
Stem Cuttings
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.
Asexual Cuttings
Grafting – using woody stems
Why do we graft?
Things to remember when grafting.
 3.
Asexual Cuttings
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.
 3.
Step 1 Selection
Step 2 - Tools
Whip Grafting
Step 3 - Cutting
stem to make
area for grafting.
Step 4 - Showing
how to make the cut.
Step 5 – Adding the cut
down through the middle.
Step 6 – Making the cut on the grafting material.
Step 7 – Making
incision into the graft.
Step 8 – Putting the
two grafts together.
Step 9 – Wrapping the
graft.
Step 10 – Finished
product.
Propagation Methods
Budding – inserting bud into
existing wood
 5. Layering – taking a stem and
promoting root growth.
 4.
Layering – Simple or mound
Layering – taking a branch and placing it
on the soil.
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.
Separation Method
Separation – you take mature
plants that were stolons or offspring
from a parent plant and separate.
 7.
Runners
Runners – stems that run along the
top of the ground. They root at the
node.
 6.
Stolons – Parent plant puts out runners and each
node a new plant forms along with roots.
Runners or Stolons
Separation of runner from parent.
Separation Method
Division
Division – taking tubers, roots,
bulbs, or corms and dividing them.
 8.
Stem Tubers – potato – eyes become plants.
Stem Tubers
Division
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.
Suckering
– growth from the root or
crown area. Would use division here
because of the roots.
 Suckers
Suckering – where plants are produced from
roots. Raspberries, willows and dog woods are
examples.
Suckering
Tissue Cultures
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).
 9.
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.
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
Factors Influencing Rooting
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).
 Hardwood
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
Factors Influencing Rooting
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.
4.
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
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
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.
Monocot Seed
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.
Dicot Seed
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.
