Verticillium Wilt Resistance in Noncultivated Tuber-Bearing Solanum Species. D. L. Corsini, USDA-ARS Research Plant Pathologist, University of Idaho Research and Extension Center, Aberdeen 83210. J. J. Pavek, and J. R. Davis. USDA-ARS Research Geneticist, and Plant Pathologist, University of Idaho Research and Extension Center, Aberdeen 83210. Plant Dis. 72:148-151. Accepted for publication 4 September 1987. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/PD-72-0148.

Noncultivated tuber-bearing Solanum species were evaluated for resistance to Verticillium wilt (Verticillium dahliae). Four of the 66 species consistently showed high resistance when wilt symptom expression and stem colonization by V. dahliae were used as evaluation criteria. These were S. berthaultii (PI 265858), S. chacoense (PI 473402), S. sparsipilum (PI 311000), and S. tarijense (PI 473228). Five hundred sixty-eight accessions were obtained from the Inter-Regional Potato Introduction Project (IR-1) and tested under short-photoperiod greenhouse conditions and long-photoperiod field conditions. Some S. tuberosum accessions and other Solanum species, such as S. microdontum, showed resistance to wilt symptoms but not to pathogen colonization. None of the accessions was completely free of stem colonization by V. dahliae after repeated testing, indicating lack of immunity. The four most resistant species are diploids (2n = 24) with a common origin in Bolivia and northwestern Argentina. They can be hybridized with cultivated diploids, thereby serving as germ plasm resources.