Artificial Cloning In Plants Flashcards
what is micropropagation?
the process of making large numbersof genetically identical offspring from a single parent plant using tissue culture techniques.
when is micropropagation using tissue culture used?
- plant doesn’t readily produce seeds.
- when a plant does’t respond well to natural cloning.
- when a plant is rare.
- when a plant has been genetically modified or selectively bred with difficulty.
- when a plant is required to be pathogen-free.
what are the basic principles of micropropagation and tissue cultures?
- take small sample of tissue from plant you want to clone. meristem tissue is often dissected out in sterile conditions to avoid contamination.
- sample is sterilised by immersing it in sterilising agents. material removed is the explant.
- the explant placed in a sterile culture medium containing a balance of plant hormones which stimulates mitosis. cells proliferate, forming a mass of identical cells known as a callus.
- callus divided into individual cells and these are transferred to a new culture medium containing a different mixture of hormones and nutrients which stimulates development of tiny genetically identical plantlets.
- plantlets are plotted into compost where they grow into small plants.
- the young plants are planted out to grow and produce a crop.
what are the materials removed in tissue culture called?
explant.
what are the arguments for micropropogation?
- micropropogation allows for the rapid production of large numbers of plants with known genetic make-up which will yield good crops.
- culturing meristem tissue produces disease free plants
- it makes it possible to produce viable numbers of plants after genetic modification of plant cells.
- it provides a way of producing very large numbers of plants which are seedless and therefore sterile to meet consumer tastes.
- provides a way of growing plants which are naturally relatively infertile or difficult to grow from seed.
- provides a way of reliably increasing the numbers of rare or endangered plants.
what are the arguments against micropropogation?
- produces a monoculture so all susceptible to the same diseaes or changes in growing conditions.
- relatively expensive process and requires skilled workers.
- explants and plantlets are vulnerable to infection by moulds.
- if the source material is infected with a virus, all of the clones will also be infected.
- large numbers of plants can be lost during the process.
what is a monoculture?
many plants that are genetically identical.
which crop was the first to be produced?
banana.
what is a wild banana like?
full of hard seeds and is virtually inedible.
what disease were Gros MIchel bananas wiped out by?
fungal panama disease.
which bananas are resistant to fungal panama disease?
cavendish bananas.
which disease is wiping out cavendish bananas?
black sigatoka.
