Hello, my name is Bradley Till.
I am the Head of the Genomics Unit at
the Centro de Genomica Nutricional Agroacuicola in Temuco, Chile.
My presentation will focus on the tilling technique and it's use in crop improvement.
Tilling is a reverse genetics technique that involves
the creation and genotypic screening of mutant populations.
In this presentation, I will first give you
some historical background on inducing mutations in plants and animals.
I will next describe the use of induced mutations in forward-genetic screens,
and review concepts in reverse genetics.
Next, I will introduce the tilling technique and summarize some of the achievements over
the past two decades including its use in polyploid crops.
I will then focus on
next-generation sequencing based technologies that
have improved mutation discovery for tilling.
I will provide some examples of using sequencing based tilling for crop trait improvement.
After this, I will describe some other strategies being applied to
mutant plant populations and to make comparisons
with targeted genome editing reverse-genetics approaches.
I will then end my presentation with an example of how
genomics technologies are adding great value to plant mutant populations,
and traditional forward genetic screens.
Prior to the 1920s,
geneticists had to rely on
rare spontaneous mutations that caused observable phenotypic differences.
This changed in the late 1920s with the work of Hermann Muller,
working with a model organism Drosophila melanogaster.
He showed that treating flies with ionizing radiation,
produced phenotypes at a rate that was orders of
magnitude higher than spontaneous mutations.
This had a profound effect on genetic research.
For this achievement, he was awarded the Nobel Prize in 1946.
Also in the 1920s,
Lewis Stadler used ionizing radiation to
create phenotypic differences in maize, wheat, and barley.
The figure on the right shows a phenotype of
a maize plant with an induced mutation in the A gene.
In this photo you can observe sectors lacking pigment.