Transcript sexo en vivo

Why do Plant Tissue Culture?
• A single explant can be multiplied into
several thousand plants in less than a
year - this allows fast commercial
propagation of new cultivars
• Taking an explant does not usually
destroy the mother plant, so rare and
endangered plants can be cloned safely
• Once established, a plant tissue culture
line can give a continuous supply of
young plants throughout the year
Why do Plant Tissue Culture
• In plants prone to virus diseases, virus
free explants (new meristem tissue is
usually virus free) can be cultivated to
provide virus free plants
• Plant ‘tissue banks’ can be frozen, then
regenerated through tissue culture
• Plant cultures in approved media are
easier to export than are soil-grown
plants, as they are pathogen free and
take up little space (most current plant
export is now done in this manner)
Why do Plant Tissue Culture
• Tissue culture allows fast selection for
crop improvement - explants are chosen
from superior plants, then cloned
• Tissue culture clones are ‘true to type’ as
compared with seedlings, which show
greater variability
Plant Tissue Culture Nutrient Media Composition
The essential (basal) components of all (most) nutrient media for plant tissue
cultures include I. inorganic (mineral nutrients) and II. organic (carbon
source, growth regulators)
I. Inorganic salts/mineral nutrients
A. Composition - essential macro- and micro-nutrients;
A nutrient is considered essential if:
a. it is required for the plant to complete its life cycle
and/or
b. it is part of a molecule that is an essential plant
constituent or metabolite, a cofactor, osmolyte, etc.
Essential Nutrients
Macronutrients (required content in the plant - 0.1% or % per dry weight) - C,
H, O, P, K, N, S, Ca, Mg
Micronutrients (requirement - ppm/dry weight) - Fe,
Mo
Na, Se and Si are essential for some plants
Mn, Zn, Cu, B, Cl,
Quantity of the Macro-Nutrient
Quantity of the Micro-Nutrient
MS medium was formulated from the ash content of tobacco callus. The higher
concentration of salts substantially enhanced cell division.
Chemical Form of the Nutrient
NO3Only
NO3-/NH4+
Types of culture
Embryo culture
Cell culture
Callus culture
Seed culture
Plant tissue culture
Bud culture
Meristem culture
Protoplast culture
Organ culture
Types of In vitro culture
(explant based)
 Culture of intact plants (seed and seedling culture)
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Embryo culture (immature embryo culture)
Organ culture
Callus culture
Cell suspension culture
Protoplast culture
Seed culture
 Growing seed aseptically in vitro on artificial media
 Increasing efficiency of germination of seeds that are
difficult to germinate in vivo
 Precocious germination by application of plant growth
regulators
 Production of clean seedlings for explants or meristem
culture
Embryo culture
 Growing embryo aseptically in vitro on artificial nutrient media
 It is developed from the need to rescue embryos (embryo rescue)
from wide crosses where fertilization occurred, but embryo
development did not occur
 It has been further developed for the production of plants from
embryos developed by non-sexual methods (haploid production
discussed later)
 Overcoming embryo abortion due to incompatibility barriers
 Overcoming seed dormancy and self-sterility of seeds
 Shortening of breeding cycle
Organ culture
Any plant organ can serve as an explant to initiate
cultures
No.
1.
2.
3.
4.
Organ
Shoot
Root
Leaf
Flower
Culture types
Shoot tip culture
Root culture
Leaf culture
Anther/ovary culture
Shoot apical meristem culture
 Production of virus free
germplasm
 Mass production of
desirable genotypes
 Facilitation of exchange
between locations
(production of clean
material)
 Cryopreservation (cold
storage) or in vitro
conservation of
germplasm
Ovary or ovule culture
 Production of haploid plants
 A common explant for the initiation of somatic
embryogenic cultures
 Overcoming abortion of embryos of wide hybrids at
very early stages of development due to incompatibility
barriers
 In vitro fertilization for the production of distant
hybrids avoiding style and stigmatic incompatibility that
inhibits pollen germination and pollen tube growth
Anther and microspore culture
Production of haploid plants
Production of homozygous diploid lines
through chromosome doubling, thus reducing
the time required to produce inbred lines
Uncovering mutations or recessive phenotypes
Callus Culture
Callus:
An un-organised mass of cells
A tissue that develops in response to injury caused by physical or
chemical means
Most cells of which are differentiated although may be and are
often highly unorganized within the tissue
Cell Culture
Cell suspension culture
 When callus pieces are
agitated in a liquid
medium, they tend to
break up.
 Suspensions are much
easier to bulk up than
callus since there is no
manual transfer or solid
support.
Protoplast culture
The isolation and culture of plant protoplasts in vitro
Different Techniques of Plant Tissue Culture:
•Callus and Cell culture
•Somatic embryogenesis
•Haploid culture
•Protoplast culture
•Micropropagation
•Organogenesis
•Production of virus-free
plants
•Somaclonal variation
• In Vitro Mutagenesis
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