Reproductive Technologies in Agriculture

BC Science Probe 9Section 3.5Pages 93-97

Reproductive Technologies in Agriculture

• Living in and around Agassiz, agriculture is an important part of our community; what are some of the different technologies used in agriculture and how do they apply to sexual and asexual reproduction?

Selective Breeding

• This is the most commonly used reproductive technique.

• This is how it works:1. The breeder takes two individuals from the same

species (plant or animal) that have the desired characteristics and breeds them with each other.

Selective Breeding

2. The breeder selects the offspring with the desired characteristics of the parents and breeds them with other individuals who also have those traits.

3. This continues for multiple generations, and eventually all of the offspring will have the desirable traits.

Selective Breeding

Selective Breeding

• Some more examples:– Beef cattle have been

selectively bred to produce high quality and quantity of muscle.

– Canola plants have been bred to improve the quality of the oil.

Artificial Vegetative Reproduction

• In chapter 2 we talked about vegetative reproduction.

• Some plants are able to reproduce by taking cuttings from a desirable plant and growing a new, genetically identical one.

Artificial Vegetative Reproduction

• You can only take so many cuttings from a plant, so scientists came up with a better way to produce clones:– They take individual cells from the plant they want

to clone and can grow them in a Petri dish that contains nutrients and growth hormones!

– Once this tiny cell grows into a seedling with roots it can be transplanted into the soil.

Artificial Vegetative Reproduction

• Grafting is another method.– It is when a branch from a tree that produces

good fruit is attached to the trunk of another tree.– This other tree usually has good roots, but maybe

its fruit isn’t great.

Artificial Vegetative Reproduction

– The bark on the branch will eventually fuse with the bark on the trunk and the branch will grow to produce fruit.

– This is very common in apples, grapes and peaches.

Artificial Insemination

• This is when a veterinarian collects sperm from a male animal and inserts in into a female animal of the same species.

• This is used often in selective breeding for desirable traits and for speed as it often produces results faster that conceiving the normal way.

Artificial Insemination

• This is used often in dairy cows and also in zoos.– This helps to increase the population of

endangered species.

• Sperm are collected from the desired male then frozen for transport or saved until the female ovulates.

In Vitro Fertilization

• This is when both the sperm and the eggs are collected from the male and the female animals.

• Fertilization happens in the lab in a Petri dish.• Then the embryos are inserted into females. – These females are usually surrogate mothers

because they are not genetically related to the embryos.

In Vitro Fertilization

• Both artificial insemination and in vitro fertilization are advantageous to farmers because more offspring with desirable traits can be produced than there would be naturally.

Hatcheries

• Since salmon use external fertilization in the wild, sometimes they are not very successful.

• Hatcheries help to ensure a higher rate of survival in these wild fish populations.

Hatcheries

• Just before they are ready to reproduce, both the male and the female fish are caught.

• The eggs and sperm are collected and mixed together in a container.

• Then the fertilized eggs are incubated the fed until they are ready to be released into the wild.

Recombinant DNA

• This technology involved combining genes from different organisms into a single molecule of DNA!– Recombinant DNA can be used to produce certain

traits in organisms.– It can also be used to produce substances from

organisms.

Recombinant DNA

• Bacteria are often used to produce substances with recombinant DNA:– Human growth hormone• To treat some forms of dwarfism

– Insulin• To treat diabetes

– Vaccines against Hepatitis B

Genetic Engineering

• Organisms with genes that have been intentionally altered are called genetically modified organisms (GMOs).

Genetic Engineering

• In the 1960’s, Canadian scientists used selective breeding to improve the colour and the flavour of the oil they produced.

• More recently, GM canola plants have been produced to resist drought and disease.

Genetic Engineering

Genetic Engineering