Breeding potatoes is fascinating. I earned my Masters in plant breeding working with wild potato species. I screened various populations of Mexican and South American species for resistance to late blight (caused the Irish potato famine and new aggressive forms of the pathogen has emerged in the last decade or so). I then began to breed in the resistance to modern potatoes.

True Potato Seed (TPS) is wonderful for especially developing countries because of ease of storage and being essentially virus free. For developed countries where great uniformity is necessary for processing it probably will never catch on. There is just too much segregation going on in TPS hybrids for most developed markets. Potatoes resist inbreeding (strong inbreeding depression), so it would be hard to inbreed parents to bring them to homozygosity so when two of them are crossed their progeny will be uniform. For countries where biomass and food is the major concern, TPS is wonderful.

A great web site is the Potato Association of America. From that site you can get a link to the US potato germplasm repository in Sturgeon Bay, WI. You may ask for seeds of material you are interested in and typically they send it out for free. I was able to visit the center a couple years ago and greatly enjoyed seeing their facility and was impressed how much they accomplish with such a limited budget.

Sincerely,
David