In an earlier post, I discussed our efforts to select new breeding lines with genetic resistance to potato virus Y. This is just one part of a larger strategy for virus management in the breeding program. Another key part that has been gaining momentum in recent weeks is our tissue culture collection. Tissue culture allows us to maintain and propagate many plants in a small space, and to do so under aseptic conditions (i.e., without introducing disease). Each plant grows in a test tube filled with semi-solid growth media, and many racks of tubes can fit inside an insulated growth chamber with controlled lighting and temperature:
Once a new breeding line is deemed to have significant commercial potential, which typically occurs after 6 years of field testing, young sprouts from the tubers are introduced into tissue culture for the first time. At this point the plants are most likely not disease-free because they have been propagated in the field for many years, so the plants are put through a virus eradication process that involves exposure to certain antiviral chemicals and environmental conditions. Grace has just transferred our first batch of breeding lines onto the antiviral media, so we’ll provide more updates on their progress later this year.