Exam 2 Part 2 Micropropagation Flashcards
(45 cards)
Plant cell/tissue culture
Sterile culture of plant parts on defined nutrient media, controlled environmental condition.
The use of cell/tissue culture
Important tool in both basic and applied studies as well as commercial application.
Crop improvement.
Micropropagation
A very large number of uniform copies of a selected parent plant in a short period of time
Basic studies of plant morphogenesis
From a single cell to recovering whole rooted plants.
Virus-free plants
Vegetatively propagated plants: potato, garlic, citrus, banana, etc.
Germplasm preservation and transport
Critical with rapid destruction of habitat and need to preserve the genetic pool.
Androgenesis/Gynogenesis for haploid and dihaploid (DH)
Obtaining homozygous plants for plant breeding programs
Embryo rescue for unique hybrids
Interspecific incompatibility- wide hybridization crosses can result in small shrunken seeds which indicate that fertilization has occurred, but the seed fails to develop
Cell selection and somaclonal variation
Create unique germplasm- Different from the original starting materials *Stress resistant plant (salt, temperature, etc.)
Protoplast fusion for somatic hybrids
An excellent material for fundamental studies
Create new crops
Secondary products
Produce massive plant secondary metabolites
Plant genetic engineering
Add unique foreign genes to enhance agronomic characteristics
Traits
Herbicide resistance Heat stress tolerance }Insect resistance Cold stress tolerance }Delayed fruit ripening Drought stress tolerance }Virus-resistance Salt stress tolerance }Vaccine production High phytonutrient }Nutritional quality Toxic heavy metal clean
Micropropagation
Asexual reproduction resulting in genetically identical copies of a cultivar
In vitro- Aseptic culture
Plants in a controlled, artificial environment using glass or plastic culture vessels, aseptic techniques, and a defined growing media.
Aseptic culture is widely used in
- Ornamental and floriculture 2. Unique forest/plantation trees 3. Vegetable and fruit crops FOR— Mass-production
Materials
Isolating a shoot tip or lateral bud: Encouraging multiple shoots or enhanced axillary branching
Other explants, such as petiole, stem, leaf sections, etc.: Direct production of adventitious shoots/somatic embryos Plant Growth Regulators
Somatic embryogenesis
From plant cells that are not normally involved in the development of embryos 1. Clonal propagation of genetically uniform plant material 2. Development of synthetic seed technology 3. Source tissue for genetic transformation
What is callus?
A wound response; an unorganized, proliferated mass of differentiated plant cells
Stages of micropropagation
- Stage I: Initiation of aseptic cultures
- Stage II: Shoot multiplication
- Stage III: Rooting
- Stage IV: Transplant (Soil)- Acclimatization
Factors to consider for micropropagation
- Media
- Environment (light/dark, temperature, photoperiod, etc.)
- Browning – usually in Stage I due to oxidation of phenolic compounds
Advantages of micropropagation
- One can clonally propagate a very large number of uniform copies of a selected parent plant. 2. Faster 3. Not limited by field seasons/environmental influences 4. Pathogen-free plants 5. Long-term germplasm storage 6. For breeding program (double haploid, maintaining a heterozygous plant population)
Advantages of conventional propagation
- Equipment costs minimal 2. Little experience or technical expertise needed 3. Inexpensive 4. Specialized techniques for growth control (e.g. grafting onto dwarfing rootstocks)
Disadvantages of micropropagation
- Specialized equipment/facilities required 2. More technical expertise required 3. Protocols not optimized for all species 4. Relatively expensive > 50 - 85% labor > Stage II: repeated cutting, transferring and > Stage III: Rooting > Stage IV: Transplant (soil)
