Propagation 2

Leaf-bud cuttings (single eye or single node)

- consists of a leaf blade, petiole and a small piece of stem with the attached axillaire bud -must regenerate roots -herbaceous and woody plants (magnolia, camalea ) -buds need to go under soil (you don't want buds to grow before roots)

stem cuttings

-1) herbaceous (non woody) not capacity to make wood which is herbaceous -2) softwood + deciduous (capable to make wood): -newest tenderous growth beginning of the season (around May -June -July) -rotation in size from small leaves on top to the bottom with bigger leaves -softwood stage is important to get it rooted.(May -June at the guidelines) -we need 6'' -condition needs to be of very high humidity, this young growth need humidity because they don't have roots to take water 3) semi hardwood (semi ripe, greenwood) -July, September: stems firmer 4) broad-leaved evergreens : July and September 5) hardwood stage (October, November, December, to March) -deciduous and needle-leaved evergreen (done in this stage) -depends on plants and species -look like sticks -make on straight (bottom) and one angle (on top) in order to know which way the stem needs to sit on the medium - rose cuttings (callus and stored)

Adventitious organs

Adventitious roots arise on aerial plants parts and underground stems and roots -needed for stem cuttings, leaf cuttings and often root cuttings -Adventitious buds: arise from any plant part other than terminal, lateral or latent buds on stems, it is a shoot. They are not dormant buds. Adventitious buds are not the same as dormant buds, they do not have a bud trace to the pith. An adventitious bud is an embryonic shoot. -Needed for leaf cuttings and root cuttings

What is cutting?

Any detached portion of a plants roots, stems or leaves used to clonally multiply plants. (Typically) Vegetate portions. Plants might mutate on their own but typically clones -asexual -seed doesn't become a clone

Polarity

Condition inherent in a cell, tissue or organ of having a definite orientation (up and down) Cuttings to be rooted (left ) were placed in an inverted position (upside down) cuttings (right) were placed in a normal upright position.

Why cuttings

Convenience (don't need to wait for proper age) Ease (easy) Maintain clones Quicker maturity Control of growth phase

2) wound induced roots

Develop after cutting is made in response wounding. These roots are considered to be de novo (anew)

Adventitious buds that are formed

Formed from wound induced secondary meristem. Meristemic region that is involved. Adventitious buds from leaf cuttings not when doing cuttings from stems

Topophysis: stem cuttings

Is defined as the effect of the position of the propagule on the plant upon the type of vegetative growth subsequently shown by the vegetative progeny -cuttings from upright shoots (orthotropic) will grow vertically -cuttings from lateral shoots (plagiotropic) will grow horizontally (never make good upright plants) - the plants need to express topophysis

adventitious roots

Roots that come from places we don't expect, dédifférenciation going backwards focusing on roots and not stems, don't come from meristem region

Cuttings

Roots/stems/leaves/

What happen when we make a cutting?

Wounded but if plant is healthy goes through a wood response, all the cells die and plant produce suberim that protects water and from pathogens. When healed, the living cells behind the necrotic parts start to make some parenchyma cells (not specialized cells), these cells divide and make callus. Plants need cell roots and the plant specialized: adventitious roots

medium

peat moss -sphagnum -shredded bark -coir -Compost -sand -perlite -vermiculite -pumice -calcined clay -rockwool -succulent only on sand

Root cuttings

-Must generate shoots, often roots, shoots first then roots -Suckers -thin roots: smaller cuttings (horizontally on medium) fleshy: bigger roots ( vertically) -observe polarity (top nearest the crown is cut flat and the bottom is cut sideways) -suckers: are adventitious shoot coming out of a root, if not coming from roots they are not suckers they are epicormic shoots or water sprouts -some plants do suckers so better take it that (woody plants)

Rooting ease

-easy to root (auxins and morphogens) -moderately easy to root (no auxins so need to provide some auxins but have morphogens) -recalcitrant difficult to root -root morphogens (co-factors): things that help rooting

medium

-hold cutting in place (physical support) -provide water (moisture) -provide oxygen (air) -provide darkness (promotes rooting) -cleaning (hot water )

Leaf cuttings in herbaceous plants only

-leaf tissue -entire leaf (blade or petiole) -section of leaf -must regenerate roots and shoots -herbaceous plants (woody plants do not respond to leaf cuttings) - you can cut leaf in the middle, slice the veins (root response for the wound and shoot response from the roots) -in leaf cuttings : roots come first bc it is easier then shoots coming from that piece we started -check for camera

plant growth regulators

-natural or synthetic chemical that shows hormonal effects -Phytohormones naturally occurring organic chemicals that regulate growth and development -Auxins (roots): IAA/IBA/NAA (most common) -cytokinins (shoots): Kinetin/zesting/BA/BAP

Cuttings types

-root cuttings -leaf cuttings -leaf-bud cuttings -stem cuttings Herbaceous Softwood Semi hardwood Broadleaf evergreen Hardwood: deciduous ...

Stages of adventurous root formation

-root initiation: Stage 1: dédifférencions of specific differentiated cells Stage 2: formation of root initials Stage 3: dvlpt of root initials into root primordia -root growth Stage 4: growth and emerged of root primordia

Taking cuttings

-turgid: well watered, early in a day or late -types: typical, Mallet (more mature tissue for mallet), Heel (sliver of much older tissue especially for conifers) -pencil thickness width for branches -wounding with knife, vegetable peeler if soft wood

adventitious roots

1) Preformed or latent root initials These ones occurred naturally, not a wound response (monocot) Already there

Cutting environment

1) temperature -medium is the bottom heat (provide heat from the bottom) (70-77) -above grounds parts no activity needed (air cooler than bottom) because we don't wan to promote top growth (40) 2) light (maintain suitable light levels for photosynthesis and carbohydrate production (shading) lower rate of photosynthesis -reduced light levels 3)Moisture: maintain an atmosphere with low evaporative demand (humidity) (mist on tenting) -miss nozzles on timer -misting with or without covering depending on what you are growing