Detection of a simplex RAPD marker linked to resistance to potato virus Y in a tetraploid potato

Extreme resistance to potato virus Y, derived from a wild diploid species S olanum chacoense, was found in Japanese cultivar Konafubuki. The segregatio n ratio of resistant vs susceptible in the tetraploid population from Kita- akari (susceptible)x Konafubuki (resistant) indicated that the resistance g ene followed a monogenic dominant fashion, Bulked DNA samples of resistant and of susceptible clones were screened with 306 decamer primers by PCR to find RAPD markers linked to the resistance. The RAPD marker 38-530 was repr oducibly detected in the resistant clones with a recombination frequency of 16.3%, Except for Konafubuki the marker band was found only in a few limit ed parental lines and cultivars where the resistance is not involved. Thus, using Konafubuki as a resistance gene source, the RAPD marker 38-530 would be practically and widely useful in tetraploid breeding programs.