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My
name is Andrew Patterson.
I'm a professor at the University
of Georgia in the United States.
And my subject is to address marker
assisted selection in agriculture.
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Perhaps the single most important
reason that marker assistant
selection has become important
is because it's frequently
very challenging to be able
look at a plant or animal
and assess its genotype
based on the way it looks,
based on its phenotype.
This is an example
from peanut, which
is the plant that's growing here.
Based on some work done by two of
my former professional colleagues,
Charles Simpson,
who's squatting down,
and James Starr, who's
sort of kneeling,
taller, they're standing
in a row of peanut that's
highly resistant to
the Root-Knot Nematode
that these two gentlemen have bred.
And next to it is a strain
that's highly susceptible.
In fact, it's near isogenic
to the line that they've bred.
This is a particularly challenging
phenotype to determine, first
of all because the organism
that's attacking the plant
lives underground,
lives in the roots.
You can't see it.
You can only see what's
happening above ground.
You can eventually see what's
happening above ground,
but by that time it's
killed the plant.
So in order to actually see
the phenotype developing,
one has to dig up the roots
and count the nematode eggs
on the roots, keeping in mind that
the nematode itself is microscopic
and the eggs are even smaller.
There might be hundreds of eggs or
even thousands of eggs on the roots
of one plant, so one
could imagine that this
would get sort of tedious.
Furthermore, in order to accurately
assess a large number of plants
for their phenotype,
one has to be sure
that one has a uniform infestation.
By, in this case,
the nematode, or it
could be some other
pest or pathogen,
or it could be an abiotic
stress like drought resistance.
One has to make sure they have the
proper environment to actually see
the phenotype develop.
In some years, nature might
dish out the proper environment.
In other years, nature might not.
And finally, once one has the
proper conditions to actually see
the phenotype, one has to be
able to visualize the data
and digitize the data in some
sort of quantitative manner.
Those things can all
be very challenging,
particularly for a trait like
this where most of the action
is underground.
