|Inglis, D. - WASHINGTON STATE UNIV|
|Dorrance, A. - WASHINGTON STATE UNIV|
|Powelson, M. - OREGON STATE UNIVERSITY|
|Lofoya-Saldana, H. - PICTIPAPA, MEXICO|
|Martin, M. - RETIRED USDA-ARS|
Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 9, 1998
Publication Date: February 15, 1999
Citation: Corsini, D.L., Brown, C.R., Inglis, D., Dorrance, A., Powelson, M., Lofoya-Saldana, H., Martin, M. 1999. Late blight resistant potato germplasm release: awn86514-2.. American Journal of Potato Research, 76:43-49.. Interpretive Summary: Late blight has once again become a major threat to potato production. The disease is caused by a fungus that for many years had been controlled by a systemic fungicide-metalaxyl. The fungal pathogen has now become resistant to the fungicide. There are protectant fungicides that still can be used to control the disease, but they often are only partially effective and generally do not control the tuber rot phase of late blight. All major varieties in the U.S. are susceptible to both leaf blight and tuber rot caused by the pathogen. Developing resistance to the new more aggressive strains of late blight has become top priority for potato breeding programs throughout North America. This germplasm release is a selection from the USDA-ARS potato breeding programs at Aberdeen, ID and Prosser, WA. It was tested against the new late blight strains in the U.S. and against the late blight strains that occur in the Toluca Valley of Mexico long considered to be the place of origin of the disease. AWN86514-2 has shown outstanding resistance at all locations and when used as a breeding parent can transfer this resistance to its progeny. It is being released as germplasm to be used by potato breeders around the world who are developing late blight resistant varieties.
Technical Abstract: 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, long-oblong, buff-skinned tubers. Specific gravity is high and French fry color from 7 C (45 F) storage is excellent. 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. This germplasm was developed and released by USDA-ARS in cooperation with the Agricultural Experiment Stations of Idaho, Oregon, and Washington.