FINALS - Unit IV Flashcards
refers to the production of plants from very small plant parts, tissues or cells, grown
aseptically in a test tube or containers under controlled nutritional, environmental and aseptic conditions.
Micropropagation
Application of Micropropagation
- Rapid rate of multiplication of a plant clonally
- Production of disease-free and disease resistant plants
- Induction of mutants and selection
- Production of haploids through anther culture
- Nitrogen fixation
Disadvatages
- Expensive and sophisticated facilities
- High cost of production results f
- Contamination or insect infestation can cause high losses in a short time
- Higher level of somatic variation
- Poor establishment of the plantlets in the
Principles and Practices in Mircropropagation
- Totipotency and plant regeneration:
- Axillary bud proliferation
- Organogenesis (Development of organs)
- Somatic embryogenesis
Stages of Micropropagation
Stage 0: Selection of mother plant for explants isolation
Stage1: Explant establishment in culture medium
Stage2: Proliferation and multiplication
Stage 3: Plant establishment and rooting
Stage 4. hardening
involves culture of both shoot-tip and axillary-bud. The use of small shoot-tips comprising of the apical dome with one or two leaf primordia (0.1-0.5 mm) is the basis for the technique
known as meristem-tip-culture, pioneered by Morel in the 1950s.
Meristem culture
A piece of sterile plant tissue with living cells is transferred¬ to a culture medium to induce callus
proliferation.
Callus culture
The cells are maintained in suspension cultures so as to produce free cells and are then subcultured to regenerate complete plant from single cells.
Cell culture
It involves aseptic excision of the embryo and its transfer to a suitable medium for development
under optimum culture conditions.
Embryo culture
From different sources, protoplasts (the plant without any rigid cellulose wall but with plasmamembrane only allowed to fuse to form a somatic hybrid) are cultured in suitable media
Protoplast culture
The culture of anthers is of considerable value to breeders as it is possible to produce haploid plants which reveal recessive alleles.
Anther culture
The greatest potential for clonal multiplication is through somatic embryogenesis, where technically
a single isolated cell can produce first an embryo, then a complete plant.
Somatic embryogenesis
a complicated structure, which consists of a short-thickened stem bearing roots on the
underside and thick fleshy leaves on the upper side.
Bulb
Types of Bulb
- Tunicate (laminate) bulbs
- Non-tunicate (scaly) bulbs
Basically four types of plant development take place in this method of scaling
- Epigeous-type plant (ETP) in
- Hypoepigeous type plant (HETP)
- Hypogeous type plant (HTP)
- Non-green leaf bulblet (NLB)
is a swollen, modified underground stem, which primarily function as the storage organ of
the plant.
Tubers
It is a specified long slender stem that develops from the axil of leaf at the crown of a plant, which
prostate horizontally along the ground.
Runners
is a shoot, which arises on a plant below the ground, arising from an adventitious bud on a
root.
Suckers
is a young plant produced laterally by the parent plant or branch that develops from the
base of main stem in some plants, which can easily be detached from it.
Off-shoots
is a modified and specialized stem structure in which the main axis of the plant grows
horizontally at or just below the soil surface
Rhizome
is a short, solid, much swollen underground stem, enclosed by dry scale like leaves, with one
or several buds near the top, a tuft of leaves at the upper side and a ring of thick fibrous roots around the base .
Corms
is an enlarged fleshy stem with several nodes
Pseudo bulbs
