Development and application of a 6.5 million feature Affymetrix Genechip® for massively parallel discovery of single position polymorphisms in lettuce (<it>Lactuca spp.</it>) oleh Stoffel Kevin, van Leeuwen Hans, Kozik Alexander, Caldwell David, Ashrafi Hamid, Cui Xinping, Tan Xiaoping, Hill Theresa, Reyes-Chin-Wo Sebastian, Truco Maria-Jose, Michelmore Richard W, Van Deynze Allen