6.4.3 Production of Artificial Clones in Plants Flashcards
What are cultivars?
Gardeners and horticulturalists can harness the natural processes of vegetative reproduction to form the basis of artificial cloning
Techniques such as cuttings, layering, grafting, division and budding have been used
This creates cultivars, strains of genetically identical plants that can endure as foodstuffs or commercial blooms for many years
All methods rely on the formation of meristematic tissue from which plant organs can differentiate
What is micropropagation and tissue culture?
Many plant cells are totipotent, unlike animal cells, and therefore an entire plant can be reproduced from any of these cells
Creating clones of cauliflowers is used to demonstrate totipotency through the production of tissue culture
Cauliflower is used because it is comprised mostly of actively dividing cells and can withstand being handled
A small piece of the plant is cut, this is called an explant, which is then grown into a new clone of the original plant
Care must be taken to disinfect the explant and to use aseptic techniques to avoid fungi from colonising the growth medium and causing the micropropagation to fail
This technique is used by scientists to reproduce endangered species of plants where relatively little source material exists
What is the method?
Wear eye protection at all times
Wipe all surfaces with disinfectant and soak all apparatus in sterilant
It is important to ensure a sterile environment so that no fungi contaminate the experiment, which would result in seeing a fungal growth rather than an explant growth
Break off a small floret of cauliflower from the plant then using a scalpel, cut a thin section of the floret (about 5-10mm long)
This thin section is the explant
Sterilise the explant by soaking it in sterilising solution for 15 minutes, swirling the explant around within the solution every 5 minutes
This ensures that the explant is sterile and therefore only cauliflower cells are present
Take out the explant using sterilised forceps and add it to a container of agar growth medium
The growth medium contains all the nutrients that the plant needs for growth and also contains a sterilant to ensure no contamination occurs throughout the experiment
Leave the container holding the agar growth medium and the explant on a sunny windowsill for 3 weeks
What are the results?
The result of this experiment is to grow a complete cauliflower clone from an explant
This shows that the cells in the explant have the capability to produce all the different cell types that make up a full cauliflower plant, hence they are totipotent
The complete cauliflower plant can then be distributed to commercial growers/garden centres in large numbers
