22.2 artificial cloning in plants

why would micropropogation be used

when a plant:

• does not readily produce seeds

• doesn’t respond well to natural cloning

• is very rare

• has been genetically modified or selectively bred

method for micropropogation

• take a small sample of tissue from the plant that you want to clone

• the sample is sterilised by immersing it in a sterilising agent such as bleach

• the material removed is known as an explant

• the explant is placed in a sterile culture medium containing plant hormones and the cells proliferate, forming a mass of identical cells known as a callus

• the callus is divided in individual cells or clumps and tranferred to a new culture medium

• the plantlets are potted into compost where they grow into small plants

advantages for micropropogation

• allows for the rapid production of large number of plants with a known genetic makeup

• culturing meristems produces disease free plants

• makes it possible to produce viable plants after the genetic modification of plants

• can produce large numbers of seedless plants

• way of increasing the numbers of rare or endangered plants

arguments against micropropogation

• it produces a monoculture so they are all susceptable to the same diseases

• it is expensive and requires skilled workers

• the explants and plantlets are vulnerable to infection by moulds and other diseases during the production process

• if the source material is infected with a virus, all of the clones will be infected

• in some cases, a large number of plants are lost during the process