Plant Propagation – Asexual Propagation

Mr. WilsonUintah High School

Agricultural Sciences

What is asexual propagation? Reproducing plant by means other than seed.

Asexual Reproduction: The reproduction of a plant without the

uniting of a pollen and ovule. Asexual reproduction is often referred to as

vegetative propagation since no seed is involved in the formation of the new plant.

It is known as a clone. Leaves, stems or roots may be used to grow a

new plant. *Produces a genetically identical plant.

What are the reasons for producing plant asexually?

The only way to reproduce certain varieties.

Assures that certain characteristics from the parent plant are carried to the next generation.

Quicker than other methods.Less expensive than other methods.

What are the types of asexual propagation?

Cuttings - using the stems and leaves to reproduce plant

Division/Separation - pulling or cutting apart groups of plants to make new individuals

Layering - producing a plant from a part of a plant while that part is still on the parent plant

Grafting & Budding - connecting two pieces of living plant material together to form a single plant.

Plant Propagation – Cuttings

What is a stem cutting?A section of stem with leaves

attached.Should have three to four leaves for best

rooting.Stem CuttingsNumerous plant species are propagated by stem cuttings. Some can be taken at any time of the year, but stem cuttings of many woody plants must be taken in the fall or in the dormant season.

How to make Stem Cuttings

Tools◦Sharp knife, single edge razor, &

disinfectant Remove all flowers & buds

◦Plant needs to utilize energy for root development

Apply Rooting HormoneUse proper soil medium

Vegetative Parts of a Plant

Stem Tip Cuttings

Normally include the terminal budStem 2-4” is used

◦Cut made just below the node◦Remove lower leaves◦Apply rooting hormone ◦Insert in media deep enough to be self

supporting◦1 node must be below the surface of the media

for root growth to occur

Stem Section Cuttings

Use middle portion of stem behind the tip cuttings, 2-4” sections are needed◦Remove lower leaves◦Cut just above a node on each end◦Handle as a tip cutting◦Position the cutting with the right end up

Axial buds are always on the tops of the leaves

Cane Cuttings Cane CuttingsFor plants with cane like stemsCut cane-like stems into sections containing one or two eyes, or nodes. Dust ends with fungicide or activated charcoal. Allow to dry several hours. Lay horizontally with about half of the cutting below the media surface, eye facing upward. Cane cuttings are usually potted when roots and new shoots appear but new shoots from dracaena and croton are often cut off and re-rooted in sand.

Heel Cuttings Used on woody

stemmed plants Shield shaped cut

made ½ way through the wood around the leaf & axial bud

Apply rooting hormone

Insert into media

Single-Eye Cuttings

Used on plants with alternating leaves

Cut ½ “ above & below the node

Apply rooting hormone

Place vertically or horizontally

Double-Eye Cutting

Used on plants with opposite leaves

Used when stock material is limited

Select single nodeCut ½” above &

below the nodeApply rooting

hormonePlace vertically

Leaf CuttingsLeaf cuttings are used almost exclusively for a few indoor plants. Leaves of most plants will either produce a few roots but no plant, or just decay.

Whole Leaf with Petiole

                                    

Whole Leaf with PetioleDetach the leaf and up to 1 1/2 inches of petiole. Insert the lower end of the petiole into the medium. One or more new plants will form at the base of the petiole. The leaf may be severed from the new plants when they have their own roots, and the petiole reused.Whole Leaf without Petiole

                                    

Whole Leaf without PetioleThis is used for plants with sessile leaves. Insert the cutting vertically into the medium. A new plant will form from the axillary bud. The leaf may be removed when the new plant has its own roots.

Leaf Cuttings

Leaf Cuttings

Made from leaf with the petiole cut to less then ½”

Make a clean cutApply rooting

hormonePlace vertically in

rooting media

Leaf Petiole Cuttings

Used on a leaf with ½” – 1 ½” long petiole

Place vertically in media

Several plants will develop from the base of the petiole

Leaf Section Cuttings

Split Vein

                      

              

Split VeinDetach a leaf from the stock plant. Slit its veins on the lower leaf surface. Lay the cutting, lower side down, on the medium. New plants will form at each cut. If the leaf tends to curl up, hold it in place by covering the margins with the rooting medium.

Leaf Section

                     

             

Leaf SectionsThis method is frequently used with snake plant and fibrous rooted begonias. Cut begonia leaves into wedges with at least one vein. Lay leaves flat on the medium. A new plant will arise at the vein. Cut snake plant leaves into 2-inch sections. Consistently make the lower cut slanted and the upper cut straight so you can tell which is the top. Insert the cutting vertically. Roots will form fairly soon, and eventually a new plant will appear at the base of the cutting. These and other succulent cuttings will rot if kept too moist.

Other leaf cuttings

Leaf Section Cuttings Leaves such as begonia are cut into

wedges, each containing at least 1 veinMake the cut in a wedge shape with the

bottom being the point◦Done so you can tell the top from the bottom

Sections are then placed in media New plants will form where the vein is in

contact with the media

Split-Vein Cuttings Used with large leaf plants such as

begonias Remove leaf from stock plantSlit veins on the bottom surface of the leafPlace the leaf on rooting media with the

slits downA new plant will form at each of the slits

Split-Vein Cuttings

Plants with large roots

                      

              

Root CuttingsRoot cuttings are usually taken from 2 to 3 year old plants during their dormant season when they have a large carbohydrate supply. Root cuttings of some species produce new shoots, which then form their own root systems, while root cuttings of other plants develop root systems before producing new shoots.

Plants with Large RootsMake a straight top cut. Make a slanted cut 2 to 6 inches below the first cut. Store about 3 weeks in moist sawdust, peat moss, or sand at 40oF. Remove from storage. Insert the cutting vertically with the top approximately level with the surface of the rooting medium. This method is often used outdoors.

Root Cuttings

Root Cuttings Use plants that are 2 -3 years oldMake cuttings when plant is dormant

◦They will have larger supplies of carbohydrates◦Top cut is straight & bottom cut is slanted

Plants with large roots◦Use section 4-6 inches long

Plants with small roots◦Use section 1-2 inches long

Root Cuttings

Store cutting 2-3 weeks in moist peat moss or sand at a temperature of 40 degrees

Large roots◦Plant vertically with the slant cut down◦Top should be flush with surface of media

Small roots◦Place cutting horizontally ½” below media

surface

Small Root Cuttings

Plants with small roots

                       

             

Plants with Small RootsTake 1 to 2 inch sections of roots. Insert the cuttings horizontally about 1/2 inch below the medium surface. This method is usually used indoors or in a hotbed.

                      

              

Single EyeThe eye refers to the node. This is used for plants with alternate leaves when space or stock material are limited. Cut the stem about 1/2-inch above and 1/2-inch below a node. Place cutting horizontally or vertically in the medium.

                       

             

Double EyeThis is used for plants with opposite leaves when space or stock material is limited. Cut the stem about 1/2-inch above and 1/2-inch below the same node. Insert the cutting vertically in the medium with the node just touching the surface.

Eye Cuttings

                       

             

Heel CuttingThis method uses stock material with woody stems efficiently. Make a shield-shaped cut about halfway through the wood around a leaf and axial bud. Insert the shield horizontally into the medium.

Heel Cutting

Cuttings

Why is rooting hormone used?To induce root formationTo increase number of rootsTo prevent root-rot.

Why do people transplant cuttings?

To maximize growth. Most cuttings are planted in small pots or flats. After they develop enough roots they are transplanted into larger pots.

How do you properly transplant cuttings?After cuttings have developed a mass of roots they

are ready to be transplanted. Great care should be used when removing the plants from the medium.

Carefully remove the cutting. Grasp the top of the cutting with your left hand, slide the right hand under the cutting, and gently lift it from the medium.

If there is excessive amounts of medium, gently shake the cutting.

Plant it in the new pot. Make sure it is no deeper than it was planted in the propagation medium. If they are planted too deep, tender stem tissue is exposed to any diseases in the medium.

Water thoroughly.

What is the proper rooting environment?Moisture -- Cuttings have no roots and

must be kept moist until roots form.Above Ground Temperature – Varies

with cropBelow Ground Temperature -- Bottom

heat 70 - 80 degrees according to cropTime

Plant Propagation – Separation and

Division

What is separation?Separation is a method of

propagation that occurs naturally in which reproductive organs of a plant detach from the parent plant to become new plants.

They are bulbs or corms.Some plants are easily propagated by

separating the main part into smaller partsPlants with rooted crowns are separated by

cutting or pulling them apartPlant the clumps separately

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Division

What is division?Division is a method of propagation

requiring the cutting and dividing of plants.

Rhizomes, tubers, and tuberous roots are used in propagation by division.

Plant Propagation – Layering

MR. Wilson

Uintah High School

What is layering?Reproducing a plant from a part of

the plant while that part is still connected to the parent plant.

In many plants stems will develop roots in any area in contact with the medium while still attached to the parent plant

Advantages◦Plant doesn’t experience water stress◦Sufficient carbohydrates are supplied to the

developing plant

What is simple layering?

Where a branch from a parent plant is bent to the ground where it is partially covered at one point in the soil.

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Simple Layering Common on:

◦Azaleas, rhododendrons, & other plantsA stem is bent to the ground & covered

with medium Wound the bottom side of the stem in the

medium The last 6-10” of stem is left exposed

Simple Layering

A portion of the stem may be buried until roots form; then the connection with parent plant can be broken. This called ground layering.

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Simple Layering

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Tip Layering Common in Raspberries & Blackberries Make a hole in the medium next to the

parent plantPlace the tip of a shoot in the hole & cover

itThe tip will grow down & then upRoots will form at the bendWhen the new tip appears above the

medium it is ready for transplanting

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Tip Layering

What is air layering?A part of the plant stem is girdled and

then surrounded by a moist growing medium in some type of enclosure.

Air LayeringAir layering is used to propagate some indoor plants with thick stems, or to rejuvenate them when they become leggy. Slit the stem just below a node. Pry the slit open with a toothpick. Surround the wound with wet unmilled sphagnum moss. Wrap plastic or foil around the sphagnum moss and tie in place. When roots pervade the moss, cut the plant off below the root ball. Examples: dumbcane, rubber tree.

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Air Layering

Stem is girdled with 2 cuts 1” apartRemove barkDust wound with rooting hormone &

surrounded in damp sphagnum mossWrap plastic around moss & tie at both

ends

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Air Layering

In a few weeks roots will appear throughout the moss

Cut the stem just below the newly formed root ball

Plant the ball into a well drained potting medium

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Air Layering

Air Layering Example

A section of stem may be wounded and covered with moist peat and black plastic covering. After roots form, the stem can be detached and planted. This is called air layering.

Layering

Tip Layering

                      

              

Tip LayeringDig a hole 3 to 4 inches deep. Insert the shoot tip and cover it with soil. The tip grows downward first, then bends sharply and grows upward. Roots form at the bend, and the recurved tip becomes a new plant. Remove the tip layer and plant it in the early spring or late fall. Examples: purple and black raspberries, trailing blackberries.

Simple Layering

                       

             

Simple LayeringBend the stem to the ground. Cover part of it with soil, leaving the last 6 to 12 inches exposed. Bend the tip into a vertical position and stake in place. The sharp bend will often induce rooting, but wounding the lower side of the branch or loosening the bark by twisting the stem may help. Examples: rhododendron, honeysuckle.

Compound Layering

                          

          

Compound LayeringThis method works for plants with flexible stems. Bend the stem to the rooting medium as for simple layering, but alternately cover and expose stem sections. Wound the lower side of the stem sections to be covered. Examples: heart-leaf philodendron, pothos.

Layering

Stolons and Runners

                       

             

Stolons and RunnersA stolon is a horizontal, often fleshy stem that can root, then produce new shoots where it touches the medium. A runner is a slender stem that originates in a leaf axil and grows along the ground or downward from a hanging basket, producing a new plant at its tip. Plants that produce stolons or runners are propagated by severing the new plants from their parent stems. Plantlets at the tips of runners may be rooted while still attached to the parent, or detached and placed in a rooting medium. Examples: strawberry, spider plant.

Stolons or Runners

Plant Propagation – Grafting and Budding

What is grafting?Grafting is a process by which two

different plants are united so that they grow as one.

The scion is the newly installed shoot or top of the plant.

The rootstock is the seedling or plant used as the bottom half of the plant. It becomes the root system of the newly grafted plant.

Why is grafting used?Rapidly increases the number of

desirable plants.Gives plants stronger, more disease-

resistant roots.To topwork a large tree. To insert a different variety on part of

the limbs of the tree.To propagate plants that may be

difficult to bud.

What are the requirements for successful grafting?Compatibility

◦The plants must be closely related to each other so the scion and stock are able to grow together.

Scion wood◦The scion wood should be one year old and of

vigorous growth.Timing

◦Grafting is usually done when the stock and scion are dormant and have no leaves.

What are the requirements for successful grafting?Matching of tissue

◦The cambium layer of the two matched plant parts must come in close contact and be held tightly together.

Waterproofing◦After the graft is made all cut surfaces must be

covered with a waterproof material like grafting wax, plastic ties, or rubber ties.

What is budding?

In budding a single bud is used instead of a scion like in grafting.

Why is budding used?

More plants can be reproduced from the same amount of parent wood.

Budding is accomplished more quickly.Budding can take place at different

times than grafting can.

What are some rules to follow to keep newly propagated plants disease-free?Hoses are not to be put in direct

contact with the ground.Keep greenhouse floor clean.Keep all benches clean of plant

material and debris. After propagating plants, clean all

equipment.Clean knives by washing off with

water, and then dip in rubbing alcohol.Return equipment to proper storage

place.

The goal of grafting is to connect or fit two tissues of living plant issue together in such as way that they will unite and subsequently behave as one plant.

Budding is the place of a single detached bud upon the stock.

Whip Grafting

Whip Grafting

T-Grafting

Tissue Culture

Small & actively growing plant part is used

Advantages ◦Many plants can be produced from one◦More efficient & economical

Materials for Tissue Culture

Clean sterile areaClean plant tissueMultiplication medium Transplanting mediumSterile glassware & toolsScalpel & tweezers

Preparing Sterile Medium – “Agar”1/8 cup of sugar1 tsp soluble all purpose fertilizer100 mg inositol (myo-inositol) 1-2 mg of thiamine 4 tsp coconut milk (from fresh coconut)3-4 grains of rooting hormone Distilled water

Procedure

Placing Tissue in Tube

Storing Tissue Culture

70 – 75 degrees of consistent warmth Well – Lighted area (not direct sunlight)Contamination will be evident in 48 – 96

hours – Remove tubes & wash When plantlets have grown to satisfactory

size, carefully transplant

Tissue Culture