|MATHEY, M - Oregon State University|
|JAMIESON, A - Agri Food - Canada|
|VAN DE WEG, ERIC - Wageningen University|
|HANCOCK, J - Michigan State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/3/2012
Publication Date: 10/3/2012
Citation: Mathey, M.M., Jamieson, A.R., Van De Weg, E., Bassil, N.V., Finn, C.E., Hancock, J.F. 2012. Marker validation for Rpf1 red stele resistance in strawberry. Meeting Abstract. 6th Rosaceous Genomics Conference.
Technical Abstract: Red stele is a devastating root rot disease in strawberries. Several sources for genetic resistance are exploited in breeding, and several race-specific R-genes were identified. Recently, a tightly linked SSR marker was found for the Rpf1 gene at Wageningen-UR, The Netherlands. One hundred and forty nine individuals with known and unknown response to this pathogen, Phytophthora fragariae, were tested in bench tests for response to two races of this disease: Canadian race 4 (A-3) isolate ONT-3, and Cdn-5 (A-5) isolates BC-23 and NOV-77 where Rpf1 confers resistance to race 4 and is ineffective against race Cdn-5. Twenty-nine individuals consisting mostly of wild accessions or recent derivatives of crosses with wild relatives were identified as having other, potentially new factors of resistance by exhibiting resistance to race A-5 and may be valuable for widening the genetic base of resistance in commercial cultivars. To avoid epistatic effects, these individuals were excluded from validation of the Rpf1 marker. For the 120 individuals that showed high disease scores for Cdn-5, 41 showed and 79 lacked the marker allele. Preliminary analysis for correlations between marker and disease scores revealed 30 deviations, 17 individuals being susceptible despite having the marker and 13 individuals having low disease scores despite lacking the marker. Causes for the lower (75%) than previously observed (99%) marker to disease correlations are being investigated.