Skip to main content
ARS Home » Research » Publications at this Location » Publication #61374
Title: LATE BLIGHT RESISTANCE AND DNA ANALYSES OF SOMATIC HYBRIDS BETWEEN SOLANUM BULBOCASTANUM AND POTATO

Author
item Helgeson, John
item JAMES, R - UNIVERSITY OF WISCONSIN
item STEVENSON, W - UNIVERSITY OF WISCONSIN
item Haberlach, Geraldine
item WIELGUS, S - UNIVERSITY OF WISCONSIN
item MCGRATH, J - UNIVERSITY OF WISCONSIN

Submitted to: Plant Molecular Biology International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: In the summer of 1994, a severe late blight epidemic in central Wisconsin facilitated a field test of somatic hybrids between Solanum tuberosum and bulbocastanum. The predominant isolate of Phytopthora infestans was a metalaxyl resistant, A2 mating type (US 8 genotype). By 9 August, 44 of the 64 test lines (including all tested cultivars) showed >95% defoliation. In contrast, 9 of the 13 BC1 and BC2 lines derived from crosses of susceptibl potato cultivars with S. bulbocastanum + S. tuberosum somatic hybrids showed good field resistance. Three of the late blight resistant lines also showed good resistance to Alternaria solani (early blight). These results indicate that heritable, field-effective resistances to both early blight and late blight can be obtained through somatic hybridization of potato with S. bulbocastanum We are now examining progency of S. bulbocastanum + S. tuberosum somatic hybrids with molecular markers for evidence of recombination and introgression. RFLP analyses clearly demonstrate that the plants are somatic hybrids and S. bulbocastanum markers are transmitted to BC1 generation in crosses of the somatic hybrids with potato. RAPD markers are currently being applied to the BC2 population with the goal of locating resistance determinants to particular chromosomes. Presently, 20 lines previously analyzed with RFLPs are being used to associate synteny groups with chromosomes.