Marker assisted selection in agriculture

Published on December 1, 2013   77 min

A selection of talks on Genetics & Epigenetics

Please wait while the transcript is being prepared...
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.
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.