PLANT PROPAGATION

Propagation• The multiplication of a kind or species.• Reproduction of a species.

Sexual Propagation• Propagation from seeds.• Pollen is transferred from the anther to the stigma. • Fertilization occurs and seeds are produced.

Germination Rates

• Percent of seeds that sprout• 75 out of 100=75%

• Rate is affected by seed viability, temperature and moisture.

• Rates vary depending on plant and quality of seed.

Seeds• Plant depth depends on the size of seeds

• larger seeds are planted deeper• water small seeds from bottom by soaking

Embryo

Endosperm

Seed Coat

Seedlings (small plants)• Transplant when first true leaves appear• Reduce humidity and water and make environment more

like outside to “harden off” plants

Seeds to Seedlings

Advantages of Sexual Reproduction• Fast way to get many plants• Easy to do• Economical

Disadvantages of Sexual Reproduction

• Some plants, especially hybrids, do not reproduce true to parents

• Some plants are difficult to propagate from seeds

Asexual Reproduction

• Uses growing plant parts other than seeds• Types of asexual reproduction:

• cuttings• layering• division or separation• budding • grafting• tissue culture

Rooting from Cuttings

• Rooting media should be about 4 inches deep• Best time of day is early mornings because plants

have more moisture• Types of cuttings:

• stem• leaf• root

Stem Cuttings

• Using a small piece of stem to reproduce plants• using hormones and dipping in fungicides help speed

up rooting

Leaf cuttings• Using small pieces of leaves to reproduce new plants• from herbaceous plants• vein must be cut

Stem Cuttings-Step 1

Gather all materials needed

Stem Cuttings-Step 2

Cut 3 to 4 inch shoot from stem tip

Stem Cuttings-Step 3

Remove lower leaves from the shoot

Stem Cuttings-Step 4

Dip cut surface in rooting hormone

Stem Cuttings-Step 5

Thoroughly moisten rooting medium

Stem Cuttings-Step 6

Stick one or more cuttings in rooting media

Stem Cuttings-Step 7

Cover with plastic wrap or place on a mist bench in a warm area away

from direct sunlight.

Stem Cuttings-Step 8

Once rooted, cuttings can be separated carefully and

transplanted

Root Cuttings• Using small pieces of roots to reproduce plants• should be three inches apart in rooting area

Layering• Scarring a small area of stem to produce new plants

• air layering• trench layering• mound layering

Trench Layering

Division or Separation

• Cutting or pulling apart plant structures for reproduction• bulbs• corms• rhizomes• tubers• runners• stolons• suckers

Bulbs

Grafting• Joining separate plant parts together so that they form

a union and grow together to make one plant.

Wedge Graft

Approach Graft

Grafting Terms• Scion-the piece of plant at the top of the graft• Rootstock-the piece of the plant at the root or bottom of

the graft

Methods of Grafting• If the scion and rootstock are the same size

• wedge• splice• whip and tongue• approach

Methods of Grafting• If the scion is smaller than the rootstock

• cleft• side• notch• bark inlay

Budding

• A form of grafting when a bud is used• patch budding• T-budding• Chip Budding

Chip Budding

How to perform T-budding

Step 1

Step 2

Step 3

Step 4

Tissue Culture• Using a small amount of plant tissue to grow in a sterile

environment• The most plants in a short time• True to parent plant

Advantages of Asexual Production• Plants mature in a shorter time• Budding is faster than grafting• In trench layering, a plant forms at each node on a

covered stem• Some plants do not produce viable seed• New plants are the same as the parent plant

Disadvantages of Asexual Reproduction• Some require special equipment and skills, such as

grafting• Cuttings detach plant parts from water and nutrient source• Some plants are patented making propagation illegal

The Uses of Biotechnology in Horticulture

What is Biotechnology?

• The use of cells or components (parts) of cells to produce products or processes

Methods• Tissue culture or micropropagation• Cloning• Genetic Engineering

Tissue Culture

• Uses terminal shoots or leaf buds in a sterile or aseptic environment on agar gel or other nutrient-growing media to produce thousands of identical plants

Cloning• Genetically generating offspring from non-sexual tissue

Genetic Engineering

• Movement of genetic information in the form of genes from one cell to another cell to modify or change the genetic make-up

Benefits of Biotechnology• Produce many identical plants in a short time• Increase disease and insect resistance• Increase tolerance to heat and cold• Increase weed tolerance

Benefits of Biotechnology• Increase tolerance to drought• Improve environment• Increase production• Other genetic changes