Plant Propagation Final Exam OSU Study

Simple layering

-Bending an intach shoot to the ground and covering a single portion of stem with soil. -Bending, twisting, cutting, or girdling stimulate root initiation

Chip budding

-a chip of wood of the rootstock is replaced by a scion chip of desired cultivars -greater production window than T-budding -greater graft union than T-bud

Corm

-a unique geophyte structure in which the base of the stem axis is swollen, had nodes and internodes in a dry membranous tunic -Structure: solid stem structure with distinct nodes and internodes

What are the Limitation of Micropropagation?

-expense -species specificity -production scheduling and marketing -pathogen contamination

What are the advantages of clones as cultivars?

-genetic improvement and selection -uniformity of populations -control of phases of plant development -combine more than one genotype into a single plant

T-budding

-limited to rootstocks that range from 1/4-1 inch in diameter -rootstocks must be actively growing so the bark will slip

Side-tongue graft

-limited to small plants -tongue provides interlock and helps support the scion

What are the advantages of Micropropagation?

-mass propagation of specific clones -production of pathogen free plants -clonal propagation of parental stock for hybrid seed production -year-round nursery production -germplasm preservation

What are the disadvantages of clones as cultivars?

-monoculture -slow and costly reproduction -potential for genetic variation -potential for systemic pathogens

Trench layering

-mother plants are established in a sloping position -shoots of established plants can be placed horizontally at the base of the trench

Sectorial Chimera

-mutated cells occupy a discrete sector of the stem, including a sector of the meristem -generally very unstable, convert to mericlinal or periclinal or revert to wild-type or all mutant

Periclinal Chimera

-mutation occupies on the outer layer of cells surrounding the meristem, inner core of cells are un-mutated -very stable

Mericlinal Chimera

-mutation occupies only part of the outer cell layer, resulting in longitudinal streaks of mutated and nonmutated cells -generally unstable they tend to convert to periclinal, or revert to the nonmutated form.

Reasons for layering sucess

-physical attachment to the mother plant -increased photosynthates and hormones accumulated in the rooting area -excluding light in the rooting zone -invigoration and rejuvenation -Utilizing seasonal effects on rooting

What is plant morphology in response to the In Vitro environment?

-reduced leaf size and number of cell layers comprising the leaf -reduced wax formation -stomatal malfunction -low photosynthetic ability

Mound layering

-shoots are cut back to the ground -as new shoots emerge, rooting medium is mounded at the base of the new shoots -new roots form at the base of covered shoots

Stage 2 Shoot Multiplication

-to maintain the culture in a stabilized state and multiply microshoots to the number required for rooting -PGR: high ratio of cytokinin

Stage 3 Root Formation

-to root microcuttings and prepare them for transfer to ex vitro conditions -PGR: high auxin ratio

Advantages of Budding

-very efficient use of scion or bud wood -may result in a stronger union -simplicity and speed -useful for amateur horticulturalists -provides flexibility

What is the criteria for successful exploitation of a sport?

1. Mutation must be dominant 2. Cells that has mutated must occupy a significant part of the meristem 3. Mutation(trait) must be conspicuous so that the new selection can be identified by that mutation

Recombinant DNA technology

a gene from one organism is inserted into the genome of another individual to produce a new genotype

Serpentine layering

a horizontal shoot or vine is covered at individual nodes for rooting

Runners

a natural form of layering in which a specialized stem grows laterally from the crown of the plant and takes root at alternate nodes to produce a new plant that provides for vegetative expansion of the original plant

Chimera

a plant is composed of a mixture of tissues with different genotypes, also referred to as mosaics

Pseudobulbs

a pseudobulbs(False bulb) is a specialized storage structure, produced by many orchid species consisting of an enlarged, fleshy section of the stem made up of one to several nodes

Patch budding

a rectangular patch of bark is removed from the rootstock and replace by a patch of bark from the scion that contains a quiescent bud

Offsets

a specialized leafy plant stem that develops from the base of many monocots and is used for propagation

Rhizomes

a specialized stem structure in which the main axis of the plant grows horizontally at, or just below, the ground surface

Bulb

a specialized underground organ consisting of a short fleshy, stem axis, bearing at its apex a growing point or a flower primordium enclosed by thick, fleshy scales

Stolons

a specialized underground stem that grows laterally from the crown of the plant to produce either another plant or a tuber.

Bud-sport

a sudden change in a single branch due to a mutation apparently arising from a single bud

Tuber

a swollen modified stem with nodes and internodes which functions as an underground storage structure as well as an organ of vegetative propagation

Vitrification

a translucent, water-soaked, succulent appearance that results in cultures that fail to proliferate

Tunicate bulb

a type of bulb scale characterized by concentric layers of fleshy tissue

Scaly bulb

a type of bulb structure in which scales are fleshy, separate, and not enclosed in a membranous layer

Bulbils

a type of bulblet produced in the aerial portion of the plant enclosed within a dry, membranous scale

Twin-scaling

a variation of bulb cutting using a segment of 2 scales with portion of the basal plate

Fleshy roots

adventitious buds and roots are produced from it

Compound layering

an entire branch is laid horizontally to the ground and covered with rooting media

Root graft

an entire root system or pieces of root serve as the rootstock for the graft

Tissue culture

an inclusive term referring to procedures used to maintain and grow plant cells and organs in aseptic culture.

Propagule

any plant part used as the starting point of a propagation process

Crippling

bending or cutting half way through the rootstock stem above the bud union

Offsets

bulblets grown to mature size

Open case

bury the graft of potted plants in moist peat

Cell suspension

callus cells grow in liquid culture that is constantly agitated. Agitation breaks cells apart, preventing them from forming large callus clump

Basal cuttage

cutting into the base of a bulb to stimulate adventitious bulblet formation

Scoring

cutting into the base of the bulb

Girdling

cutting through the bark and cambium completely around the rootstock stem

Mutation breeding

development of new clones with the use of mutagenic agents

Leptomorph

elongated, indeterminate rhizomes

Somatic hybridiation

fusion of protoplasts from two genotypes/species

True-to-Name(TTN)

implies that the plant conforms to the specific characteristics of the specified cultivars

True-to-Type(TTT)

implies the plants conform to the phenotypic expectations of the specific cultivars

Scaling

individual scales are removed from mother bulb, and adventitious bulblets form at the base of each scale

Layering

is a way of rooting cuttings in which adventitious roots are initiated on a stem while still attached to the plant

What is the goal of vegetative propagation?

is to select a single source plant of superior characteristics and to reproduce populations of progeny plants with identical genotypes that are its direct descendents.

Propagation Ratio(PR)

number of new microshoots produced per subculture

Side-veneer graft

often graft is covered with moist peat by burying the potted plant until scion has healed.

Mutation

permanent genetic change involving some part of the DNA molecule

Protoplast culture

plant cells without a cell wall, removed by microbial enzymes

Ovule culture and Ovary culture

pollen is added to the ovary while it is forming in tissue culture, resulting fertilized embryos

Aseptic Seed Culture

primarily used for orchid seed germination because the seed is so small and contains no seed storage reserves

Back bulbs

pseudobulbs that do not have foliage

Green bulbs

pseudobulbs that have foliage

Scooping

removal of basal plate

Callus

results from cell division of non-differentiated parenchyma cells

Crowns

root-stem juncture of the plant

Seedling selection

selecting a single plant that is genetically unique from a seedling population to be the start of a new clone cultivar

Pachymorph

short, thick, fleshy determinate rhizome

Inverted t-budding

similar to t-budding but the cut is inverted to allow for better drainage

Synthetic seed production

somatic embryos enclosed in an artificial seed coat, which may be a way of sowing somatic embryos for mass propagation

Tuberous roots

swollen root system attached to the crown

Tuberous stem

swollen stem produced by enlargement of the hypocotyl

Drop layering

the bases of shoots in plants established in containers and covered

Somatic Embryogenesis

the development of embryos from vegetative cells rather than from union of male and female gametes

Anticlinal

the direction of cell division in an end-to-end position to produce a continuous layer

Periclinal

the direction of cell division in an side-to-side position to increase numbers of cell layers

Hot-pipe callusing system

the graft union is kept warm by recirculating hot water in a PVC pipe

Organogenesis

the process of developing adventitious organs, such as leaves, shoots, or roots, form cells or tissues

Subculturing

the process of dividing stems or tissue from a tissue culture into smaller pieces and then transferring them to a fresh medium to multiply the tissue culture

Clonal selection

the process of selecting an individual plant or plant part to create a clone

Cloning

the process of vegetatively propagating a clone

Bark graft

the scion is inserted between the bark and wood of the rootstock

Tubercle

the small aerial tubers produced in leaf axils of certain species

Embryo culture and Embryo rescue

tissue culture of immature embryos that require controlled conditions to complete development

Stage 1 Establishment

to successfully place an explant into aseptic culture and an in vitro environment that promotes stable shoot production

Approach graft

two independent, self-sustaining plants are grafted together

Light

typical irradiance level between 40 and 80 umol

Bulblet

underground miniature bulb

Side-stub graft

used for branches that are too big for whip and tongue, but not large enough for cleft graft

Somaclonal variation

variation induced in plants produced from populations of cells in culture

Closed case

waxing may be omitted if bare-root grafts are protected in boxes containing moist peat

Air layering

wrapping an girdled aerial stem with rooting medium and causing adventitious roots to form

What are mutation agents?

x-rays, gamma rays, neutrons, chemicals

Air exchange

Co2, O2 C2H4 impact shoot development in culture

Protoplasts can absorb ________, proteins, and other large macromolecules

DNA

What are the 5 factors that affect the control of the tissue culture environment?

Temp, light intensity, photoperiod, light quality, air exchange

Bulb cutting

a bulb is cut into fragments of 3 or 4 bulb scales attached at the basal plate

Indirect Organogenesis

a developmental sequence involving an intervening callus stage