|Hanneman Jr, Robert|
Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: April 20, 1998
Publication Date: N/A
Technical Abstract: As a part of the joint National Cooperative Enhancement Project, materials are being evaluated for resistance in untreated plots at Hancock, WI. The following is a summary of field data taken this past year. Late blight evaluations were done in the field on 665 clones exposed to natural late blight infection. All materials were killed, except for foreign breeding stocks CEX-69-1 (20% defoliation), PI 517317 (30%), and the bacterial wilt line MS 35.9 (10%). Excellent resistance was noted for several Mexican species. Clones of some families exhibited only 20-30% defoliation. Among late blight differentials, only 1521C (3), showed resistance at the season's end. A comparison between 1996 and 1997 indicated that CEX-69-1 and PI 527315 were the most resistant. Verticillium wilt evaluation included 630 clones. Those showing no symptoms will be screened a second year. Flava, Nevkij and HET 1278-2 showed no visual symptoms of Verticillium wil early or late blight. Colorado potato beetle evaluations were completed on 635 clones. All were defoliated, though some exhibited only 10-30% defoliation until late season. High levels of resistance were noted among some families, whose wild species parent had been reported to be resistant. The best resistance was noted for hybrids involving S. chacoense PI217451 and S. tarijense PI473243. In conclusion, there are some promising late blight, Verticillium wilt and Colorado potato beetle resistant materials that will provide new and augment existing sources of resistance in our cooperative national enhancement effort. Wild species, the basis for much of the resistance observed, are truly the golden nuggets of nature!