Asexual propagation

Why use asexual propagation?

• Uniformity• Propagate non-seed producing plants• Avoid seedborne diseases• To create insect or disease resistant plants• To incorporate environmental tolerances• To reproduce and retain the genetic traits of a hybrid• Control size and form of a plant• Can be faster and easier, cheaper

Disadvantages of asexual propagation

• Uniformity• Short storage time• Bulky• Systemic infections can be spread

Types of asexual propagation

• Specialized parts• Cuttings• Layering• Grafting• Tissue culture

Specialized plant parts

• Offshoots• Separation• Division

Division

Division - rhizomes

Division of rhizomes

Division

Division

Division – fleshy roots

Division – tuberous roots

Separation

• Bulbs• Corms

Separation – bulbs

Separation – bulbs

Separation - bulbs

• Amaryllis (a tunicate bulb)

Scooping bulbs

Separation – scaly bulbs

Separation - corms

Cuttings

• Herbaceous• Woody plants

– Softwood– Semi-hardwood (ripe)– Hardwood

Cuttings

• Herbaceous– Stem– Stem tip– Leaf bud– Leaf

Leaf cuttings

Whole leaf cuttings

Leaf cuttings

Keep moist at all times

Leaf cuttings

Cuttings from variegated plants

Roots tend to develop at nodes

Cuttings

• Softwood – late spring, new growth

• Semi-hardwood (ripe) – summer, recent growth

• Hardwood – late fall (dormant), 1 yr. growth

Semi-hardwood (ripe) cuttings

Semi-ripe: Leaf-bud cuttings

Cutting principles• Age of material• Correct seasonal timing• Sterile rooting medium, sanitation• High humidity• No direct sun• Shoots without flowers or flower buds• Node near base of cutting• Rooting hormones• Basal wounding of woody cuttings• Remove leaves in contact with rooting medium

Bottom heat aids in rooting

Cutting resources

• Fine Gardening Magazine online• University Ag Extension sites

– NCSU– Purdue– Univ. of Missouri

Campbell University

Mission statement

God and plant propagation

• " 'This is what the Sovereign LORD says: I myself will take a shoot from the very top of a cedar and plant it; I will break off a tender sprig from its topmost shoots and plant it on a high and lofty mountain. 23 On the mountain heights of Israel I will plant it; it will produce branches and bear fruit and become a splendid cedar.” (Ezekiel 17)

Runners

Layering

Types of layering

• Simple layering• Tip layering• Compound layering• Mound layering• Trench layering• Air layering

Tip layering

• Limited to brambles

Simple layering

• Layer in Spring with 1 yr. old wood –rooted by fall--remove

Rooting layers

Compound (serpentine) layering

• Use with flexible vines

Mound layering

• Used for rootstock production in nursery trees

Trench layering

Air layering

• Developed by Chinese

Air layering

Grafting

Why graft?

• Incorporate disease, insect resistance (link)• Incorporate temperature tolerance• Quickly increase # of a desirable type• Change cultivar of fruit in an orchard• Control form (dwarfing, weeping, tree mums &

roses)• Repair bark damage

Grafting principles

• Contact between vascular cambium of scion and rootstock

Grafting principles

• Taxonomic compatibility• Timing of graft (dormant scion)• Waterproof graft junction• Rootstock diameter > scion diameter

Whip or Tongue grafting

• Most common grafting method

Grafting over

• Adding a cultivar to an established fruit tree– Replace the existing cultivar– Add a new pollinator– Try a new cultivar

• Top-working• Frame-working

Bark grafting (Rind graft, p. 437)

Cleft grafting

Topworking

Double working (p. 440)

• Using an interstock to graft an incompatible scion to a rootstock– Interstock is compatible with both scion and

rootstock

Side grafting

Approach grafting

• Use when detached scion not possible

Flat grafting cacti

Budding

• Scion is a bud• Used to propagate fruit trees, roses

T-budding

Chip budding

Patch budding

Bridge grafting to repair damage

Bridge graft to strengthen a narrow crotch angle

Inarching to repair damage

Grafting information online

• UGA Extension Service• NCSU Home propagation• Texas A & M

Micropropagation

• Utilizes cell and tissue culture• Home tissue culture