L8: Plant Improvement and Tissue Culture Flashcards
What is plant tissue culture
growth and development of plant seeds, organs, explants, tissues, cells or protoplasts on nutrient media under sterile conditions
What are biotechnlogy techniques needed for plant improvment
micropropagation => manipulate plants in vitro
vector + construction => recombinant DNA tech
genetic tranformation =>DNA transger
Define Explant, Plant Callus, Totipotency, Differentiation
Explant: the “original” tissues and cells
that are used to start tissue culture
Plant callus: a mass of undifferentiated
cells that grow over an explant
Totipotency: The capacity of a cell or
tissue to give rise to an entirely
differentiated organism.
Differentiation: Transition from meristematic
cells to specialized cells
What do explant and plant callus consit of
explant: leaves, roots, meristems, shoots, floral sections
plant callus: shoot, root embryonic
List methods of embryo/organ development
Zygotic Embryogenesis: The formation of a zygote after fusion of a sperm and egg cell and housed in a seed.
Tissue culture
Somatic embryogenesis:
The formation of an embryo from
cells other than sperm-egg
fusion; does not occur in nature.
Organeogeniss: development of organs from non meristematic cells
What are the adv of Tissue culture/Uses
- Mass propagation of specific clones
- Alternative propagation methods (“special
needs” plants) - Production of pathogen-free plants
- Clonal propagation of parental stocks for
hybrid seed production - Year-round nursery production
- Genotype modification—targets for
transformation - Plant regeneration after transformation
- Germplasm preservation
- Micrografting
- Reforestation/preservation
What are disadvantages of tissue culture
- expensive
- sophisticated facilitites
- only trained profs
- contamination can be lethal
- species + genotype specificty
- off type production (variability)
What are the stages of tissue culture
- Select and prepare explants
- Establishment of aseptic cultures
- Shoot production
- Rooting
- Transfer plants from cultures and sterile
conditions
How do you acheive shoot production
via organogenesis
* repeated enchanced formation of axillary shoots from top to lateral buds
* increase cytokinin concenstraction
* low to no auzin levels
* subculture for 4-8 weeks
How do you do rooting + transfer out of cutlure
- In vitro rooting for few weeks
up cytokinin down auxin - After rooting, transfer to non-sterile
environment (potting mix in pots) - Harden off from 100% humidity to
ambient humidity
What are issues with transferring rooted plants out of tissue culture
Desiccation from low stomatal control
low vasculature connectivty
Pests and contaminants
photosynthesis
What are plant growth regulators
hormones
* use 0.001-10um
* sensitivty to high temps
* PGR interact with specific target tissues causing different physio responses
What are methods for generating haploid plants (MAIN)
- anther culture
- microspore culture
- naturally occurring haploid
- interspecific crossing
List Factors affecting anther culture
genotype
growth conditions of donor plants
pretreatment of anthers
developmental stage of the microscope
culture medium/conditions
regeneration
How do you make a microspore culture
- Harvest anthers or whole flowerbuds
- Crush to release microspores
- Filtrate to remove debris
- Sediment microspores by centrifugation
- Resuspend and culture in liquid media
- Tobacco, oil seed rape and barley
