Late blight resistant potato germplasm release AWN86514-2

Potato breeding selection AWN86514-2, Solanum tuberosum gp tuberosum, is being released as germplasm that is highly resistant to prevalent North American strains of Phytophthora infestans. This selection has been tested under field conditions in Mount Vernon, Washington (P. infestans US11 and US8 with complex virulence pathotypes), as well as Corvallis, Oregon, and eight other locations in North America (predominantly P. infestans US8) between 1994 and 1997. Both foliage and tubers show partial resistance. Although AWN86514-2 is pollen sterile, it can be successfully used as a female parent. An average of 34% of the progeny from crosses between AWN86514-2 and four susceptible clones were resistant to late blight when tested at Toluca, Mexico, in 1996. AWN86514-2 also has high resistance to Verticillium wilt and potato virus Y. AWN86514-2 is late maturing, with medium yields of smooth, longoblong, buffskinned tubers. Specific gravity is high and french fry color from 7 C (45 F) storage is excellent. The male parent of AWN86514-2 was Ranger Russet, a dual purpose french fry and fresh market variety, and the female parent was KSA195-96, a selection made at Aberdeen, Idaho, from Polish germplasm received as true seed from the Polish Plant Breeding and Acclimatization Institute. Possible sources of the late blight resistance in this clone include S. acaule, S. demissum, S. phureja, S. simiplicifolium, S. stoloniferum, and S. tuberosum gp andigena which are in the lineage of KSA195-96. This germplasm was developed and released by USDA-ARS in cooperation with the Agricultural Experiment Stations of Idaho, Oregon, and Washington.