1. Genetic Manipulation Selective Breeding Artificial Insemination
Vegetative Propagation
Genetic engineering and transgenics

2. How can we manipulate species?
Genetic manipulation
An outline of the principles is required, with advantages, disadvantages and limitations.
Selective breeding, outbreeding and crossbreeding
• Outbreeding involves breeding between individuals that are not closely related.
• To delete undesirable characteristics.
eg to prevent recessive inherited diseases, such as deformed spines and poor lung development in cattle.
• To enhance desirable characteristics
eg yield, growth rate, nutritional value.
• To combine different desirable characteristics
eg Zebu cattle (heat tolerance) × Ayrshire cattle (high milk yield).

3. Manipulation of the food species. Genetic Manipulation by Breeding
Use the text book or the internet to find out the following;
What is selective breeding?
What is cross breeding?
What is inbreeding?
What is hybrid vigour and heterosis?
What is the difference between asexual reproduction and sexual reproduction?

4. What are the desirable characteristics of these species?1 2 3

5. 4 5 6 7

6. Calves with high yield of low fat milk, good meat production & docile
Selective Breeding
Selective breeding involves:
Identifying the characteristics or “traits” that you want e.g. low fat content in cow milk or fast growth rate in rice
Selecting the 2 unrelated individuals you are going to use
Mating these 2 together (out-breeding)
Selecting the offspring that show the desired characteristics
Cow 1:
High milk yield Low fat milk
Bull 1:
High beef yield Docile
Mate With X
Calves with high yield of low fat milk, good meat production & docile

7. Aims of Selective Breeding
Crop/animal
Desired characteristics
Bulls
Rice
Wheat, Potatoes
Tomatoes
Cows

8. Aims of Selective Breeding
Crop/animal
Desired characteristics
High meat: fat ratio
High food conversion ratio/Gross Growth efficiency
Bulls
Good response to fertilisers
Stem strength
Resistance pest and drought
Rice
Wheat, Potatoes
Drought, pest & frost tolerance
Tomatoes
Uniformity of appearance
Resistance to viral attack
Improved taste
Cows
High milk production
Low fat content of milk

9. Rice Breeding
The International Rice Research Institute in the Phillipines has been breeding rice since 1959
They collected hundreds of different varieties & selected those with desirable characteristics
They cross-bred useful varieties by taking pollen from one variety and brushing it onto the stigmas of another variety
The seed that formed was sown and the resulting plants assessed.
Promising plants were then cross – bred again etc etc

10. Rice Breeding Miracle Rice (IR8) Dwarf variety from China x
Tall variety from Indonesia
4 generations of breeding
Dwarf
Strong stem
Fast maturing
High yield
IR8
Problems:
Susceptible to disease
Became hard after cooking
Breeding with 13 more varieties
More crosses
IR36
Semi-dwarf
High yield
Fast maturing
Disease resistant
IR72

11. Selective Breeding of Cattle
Breeding closely related individuals results in in-breeding
This increases the chances of harmful, recessive genes being expressed
To avoid this, farmers keep careful records of all crosses and individuals from very different genetic lines are periodically crossed = outbreeding
Outbreeding results in hybrid vigour

12. What are the advantages of selective breeding?
Selective breeding has produced varieties that have:
Improved food conversion ratios
eg faster crop growth rates, increased Gross Growth Efficiency of livestock
eg short stemmed cereals convert more energy into harvestable crop
Desirable qualities
eg better taste, improved nutritional content
Pest and disease resistance
eg potatoes that are resistant to fungal disease
Uniformity of appearance
eg fruit of the same size and shape to suit retail needs
Timing of growth stages
eg cereal crops that are all ready for harvest at the same time
Dependence on husbandry by humans
eg highly productive crops that rely on high fertilizer and water inputs. Genetic crop uniformity may require the purchase of F1 hybrid seeds every year.

13. This ppt can be found at Z:\Geography\Env STUDIES\ENVS4\2014 Selective Breeding.ppt
Research task- Manipulation of the food species. Selective Breeding, Methods of Reproduction.
Vegetative propagation (including micropropagation)
Artificial Insemination
Embryo transfer.
For your selected method of reproduction research the following;
An explanation of the science behind the technique
An example of a species on which this techniques is used.
Advantages and disadvantages of the technique
Set your work out under the headings.
Add pictures and web references.
Save your work to X:\Geography\Environmental Studies\Agriculture

14. Artificial Insemination
Sperm is obtained from, for example, a desirable bull and frozen
It can then be injected into females without the need for mating
This allows hundreds of cows to be fertilised so that desirable characteristics can be developed in many herds
The desirable traits of a bull can be maintained long after the actual bull has died and so farmers do not need to keep the bulls
Farmers can insure fertilisation of many cows is synchronised, allowing easier management of the herd
However, if many cows are inseminated using sperm from a small number of bulls, there is a risk of reduced genetic diversity (remember the elms!)

15. Embryo Transfer Advantages
Cow with desired characteristics (e.g. high milk production or high protein/low fat content of milk) is treated with follicle-stimulating hormone (FSH). This hormone causes the cow to produce more eggs.
Advantages
The sex of the introduced sperm can be chosen. So if a farmer wants males for beef cattle he will choose Y sperm. If he wants cows for milk he will choose X sperm
With sheep, this technique can be used to produce multiple offspring, rapidly increasing flock size
Using FSH allows control of the oestrus cycle of the herd, thus when and how many pregnancies occur

16. There are two techniques available for embryo transplantation:
Embryo Transfer
There are two techniques available for embryo transplantation:
Technique 1:
Sperm from a desired bull is introduced into the cow by artificial insemination
The sperm fertilise some of the eggs and embryos develop
Embryos are removed from the cow after 6-8 days before they attach to the uterus wall
Embryos can be frozen in liquid nitrogen and used later, or directly transferred into the uterus of the recipient cow

17. There are two techniques available for embryo transplantation:
Embryo Transfer
There are two techniques available for embryo transplantation:
Technique 2:
Eggs are removed from the ovaries of dead cows and cultured in a laboratory
The eggs are fertilised using desirable sperm and the embryos are grown
The embryos are then transferred to the recipient cows

18. Vegetative Propagation
Some plants reproduce by turning their stems or roots into new plants
Example 1: Strawberry plant
Mother plant produces runners from buds near the ground
Daughter plant eventually grows its own roots
Runner dies: we now have two separate strawberry plants

19. adventitious root system
Vegetative Propagation
Some plants reproduce by turning their stems or roots into new plants
Example 2: Potato plant
aerial shoot
stolon
daughter bulb
adventitious root system
old potato (tuber)
Nodes in the buried stem produce stolons. The stolons grow horizontally through the soil and tubers form at their tips. Each tuber is capable of growing into a new potato plant

20. Vegetative Propagation
Advantages
Vegetative organs are bigger than seeds – so the new plant gets lots of food and can out-compete other plants
Disadvantages
Most types only produce small numbers of new plants
Being genetically identical the entire population may be wiped out by a disease

21. Genetic Engineering and Transgenics
A transgenic organism or genetically modified organism is one that has had a gene from another organism inserted into it
Aims of genetic engineering:
Increase growth and yield
Reduce the need for chemical pesticides and herbicides
Reduce water use
Develop plants that are productive in marginal farmland
Increase nutritional quality
Improve flavour and appearance
Improve plant qualities for harvesting, shipping and storage
The genetic code is universal – a gene that codes for a useful protein in a bacterium will, if it is cut out and inserted into a cow, produce the exact same protein in the cow

22. Genetic Engineering and Transgenics
Maize and the corn borer
Maize is attacked by corn borer insects
A gene from a bacterium ( Bacillus thuringiensis ) has been chopped out of the bacterium and inserted into maize
The gene codes for production of a protein called BT toxin which kills any corn borer that feeds on the maize
Q What are the benefits of Bt maize?
Higher crop yields
Reduced use of insecticidal sprays
Reduced cropland, more for conservation?
Q What are the possible problems?
Humans or other animals that eat the maize may be harmed by the BT toxin or the bacterial DNA
Non-target insects may be killed, disrupting food chains and pollination
Spread of the gene into wild plant species with unknown consequences

23. Transgenic Livestock
A useful gene can be inserted into a zygote nucleus, sperm cells or into body cells using special viruses
By inserting useful genes into livestock we may be able to improve characteristics such as:
Growth rate and body composition e.g. pigs
Disease resistance
Reduced lactose content of milk
Pronuclear injection or nuclear transfer
Transgenic founder animals
Increased milk production
Increased feed and usage growth
Improved carcass composition
Increased disease resistance
Enhanced prolificacy and/or reproduction
Producing transgenic animals is problematic because:
Most characteristics are controlled by several genes, not just one
Transferring genes so that they are expressed is extremely difficult and expensive

24. Combining GM with Crossbreeding
Read the passage and answer the questions
Consumers do not like GM. Now Monsanto and DuPont are turning to marker-assisted selection (MAS). This involves analyzing plants for genetic markers associated with desirable traits, then using conventional breeding methods to introduce the genes into a host. The markers are used to quickly identify the superior seedlings.
For example, a wild apple variety might have a brilliant red skin. Scientists scan the apple's genome for the gene responsible. They then search the chromosome containing the skin colour gene for a unique and easy-to-identify segment - the marker. After crossbreeding the wild apple with a domestic variety, scientists look for the genetic marker rather than waiting a few years to see which of the seedlings picked up the red skin trait.
This is much faster than growing the seedlings to see which trees have the red-skinned apples.
Questions for discussion
Suggest why consumers “ do not like GM”
What problems does this technique overcome?
Is this an example of transgenics?

25. Task Working in groups, prepare short reports on the folowing issues:
Bt crops and Monarch butterflies – is there a problem?
Isn’t genetic engineering just faster selective breeding?
Is there any evidence that genes inserted into crops can spread to and harm wild plants?
Does the use of GM crops really reduce pesticide use?