Plant propagation

What are 3 advantages to propagation?

1. Can select genes

2. Uniformity

3. Control of juvenile and mature phase

What are 3 disadvantages of propagation?

1. Monoculture

2. Slow & costly

3. Mutations can go unnoticed

Superior clones

Induced mutations from X-rays/gamma rays

Jumping genes

Mobile genetic factors that move from place to place on chromosome DNA
Turns genes on or off when present

Ortet

Original seedling tree

Ramet

Vegetative progeny

L1

Epidermal cells, small marginal islands: anticlinal

L2

Inner cortex layer: anticlinal

L3

Inner most roots & vascular (anticlinally & periclinally)

What type of chimera is this and define

Mericlinal: mutated tissue on only part of outer cell layer
Unstable

either becomes periclinal or reverts to non-mutated form or produces variable mericlinal shoots

What type of chimera is this & define

Periclinal: mutated tissue on outside layer of cells surrounding core of non-mutated tissue

Very stable

What type of chimera is this & define

Sectorial: mutated cells extend through all cell layers but only in one section

Reverts to periclinal/mericlinal or loses chimera

How long does a patent last?

20 years, exclusive rights to owner

How long does a trademark last?

10 years, can be renewed

Adventitious

Roots arising from any plant part other than those formed from normal development of seedling root meristems

What are the 4 stages of adventitious root formation?

1. Dedifferentiation

2. Formation of root initials

3. Root primordia develop

4. Root emergence

What is the difference between direct and indirect root formation?

Direct: roots don’t form on callus

Indirect: adventitious roots form on callus

What is the difference between primary and secondary meristems (leaf cuttings)

Primary: descended from embryonic cells, never ceased being meristematic

Secondary: dedifferentiation & creation of new meristems on base of leaf blade or petiole

4 Advantages of Cuttings

1. Cheap

2. Space efficient

3. Fast & simple

4. No special techniques required

4 Advantages of Pruning Stock Plants

1. Disease free

2. True to name

3. Juvenility maintained

4. Increases # of cuttings

Wood cuttings: Where to take from Hardwood & Softwood

Softwood: terminals

Hardwood; laterals

3 Goals of Intermittent Mist

1. Reduce air temp.

2. Reduce transpiration

3. Increase humidity

3 Advantages of Enclosed Mist System

1. High humidity

2. Uniform

3. Less water needed

2 Types of Nozzles: what are they & define

1. Deflection & anvil

   1. Stream of water hitting flat surface

      1. Coarse mist

      2. Cheaper

      3. Clogs less

   2. Pressure jet

      1. Less water

      2. Clogs

      3. Finer mist

      4. Expensive

Goal of misting plants

Keep a thin layer of water on foliage

3 Reasons to use Seedling Rootstock

1. Readily available

2. Virus free

3. Better root systems

5 Reasons to Graft

1. Multiplying a clone

2. Novelty plants

3. Unique plant forms

4. Repairing injuries

5. Double working -using interstock

How do Grafts Form?

The scion & rootstock form a callus bridge that grows towards each other & form together then it forms the cambium & starts to divide new phloem & xylem

4 Tips for Successful Graft

1. Align cambium layers

2. Dormant scion, recently active rootstock

3. Prevent drying

4. Polarity

3 Causes for Incompatibilities

1. 1. Adverse physiological response between scion & rootstock

   1. Only fixable if non-translocatable

2. Virus or phytoplasma transmission

3. Anatomical abnormalities

4 External Signs of Unsuccessful Graft

1. Yellow foliage at end of growing season

2. Reduced growth

3. Premature death

4. Rootstock suckering

2 Reasons for Dwarfing

1. Anatomical features

2. Hormones- reduced conc. of auxin, higher rations of ABA

What is a Bud Graft?

1 bud and small section of bark

3. Reasons for Bud Grafting

1. Young plants or small branches

2. 90-100% success

3. Propagating wood is scarce

3 Reasons Fall Budding is Better?

1. Higher temp promote extensive bud union formation

2. No storage needed- budsticks

3. Buds grow earlier following spring

Chip Budding (4)

1. Puzzle piece rootstock, scion cut to size

2. Unions stronger than T-bud

3. New growth vigorous

4. More uniform plants

4 Layering Advantages

1. Continual supply of water

2. Less maintenance

3. Propagation performed on site

4. Easy

2 Layering Disadvantages

1. Slow root development

2. Small number of plants produced

3 Tips for Layer Success

1. Girdling

2. Bending of stem

3. Add auxin

Simple Layer

Bend shoot to ground to create adventitious rooting then bend the bottom of U to stimulate rooting and pin down shoot

French Layering

Branch laid horizontally to ground, many shoots develop along length

Which layering method is used for fruit understocks and produces most plants?

Mound

In Vitro

In a culture vessel w/ a controlled environment & nutritive medium

3 Categories in Establishment: Microprop (Ex-)

1. Explant source

2. Explant disinfestation

   1. Wash in soapy water w/ 10-20% bleach

   2. Remove leaves from shoot

What hormones are added to culture medium?

At first only cytokinins then during rooting only auxins

Both during establishment

4 Steps of Microprop

1. Establishment

2. Multiplication

3. Rooting

4. Acclimatization

How to acclimatize microprop?

Greenhouse then outside

3 Differences of Microprop leaves

1. Reduced cuticular waxes

2. Thinner

3. Less functional stomata

2 Characteristics of Microprops

1. High vigor

2. Increased branching

5 Parts of Microprop Facility

1. Preparation area- kitchen where media is made & dispersed

2. Autoclave

3. Transfer area- area where explants are placed in culture & transfers/subcultures are done

4. Laminar flow hood

5. Growing area