Plant breeding
An introduction to plant breeding.
Simple articles that explain what plant breeding is and why it is necessary, the underlying principles of plant breeding and a number of important modern techniques that have contributed to the crops we have today.
Marker assisted breeding
Marker assisted breeding uses our knowledge of the genetic background of various traits to speed up plant breeding.
The detail
By identifying an area of DNA that is associated with a certain trait the process of plant breeding can be speeded up considerably. This section of DNA is known as a DNA or genetic marker and can be a gene responsible for the trait in question or a section of DNA close to it.
Knowing an associated genetic marker reduces the time needed to breed the trait into a plant. Rather than having to wait for the offspring from a cross to grow and testing these offspring in an appropriate way to reveal the trait (whether it be for disease resistance, yield or salt tolerance) thousands of plants can be quickly and easily screened for the genetic marker in question and hence the trait its self.
A micro-array. Each of these dots is a particular bit of DNA - they could each be DNA from a separate plant. More DNA (this time with a flourescent label attached) is then washed over the micro array, this is called a probe, if it contains a section of DNA which matches the DNA on a particular dot it will stick to it turning that dot flourescent. In this way a plants DNA can be searched for a particular section of DNA/DNA marker. The microarray above has actually been searched with two different probes, hence the different colours.
Photographer: Graham Seymour. Copyright: All rights reserved
As the selection of plants containing a specific trait may have to occur many times during the breeding process, for example during the repeated selection and back crossing necessary when breeding a trait from a wild plant into a crop plant, marker assisted breeding can significantly reduce the time needed to breed a trait in.
