Author
 |
HAYMES, KENNETH - CONTRACT EMPLOYEE |
|
Hokanson, Stan |
|
VAN DE WEG, W - CPRO, WAGENINGEN, NL |
|
HENKEN, B - CPRO, WAGENINGEN, NL |
|
Maas, John |
|
Submitted to: Meeting Abstract
Publication Type: Proceedings Publication Acceptance Date: 5/11/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Commercial strawberry (Fragaria x ananassa) is susceptible to red stele root rot caused by the fungus Phytophthora fragariae Hickman var. fragariae. Symptoms of the disease include dwarfism, wilting of leaves and petioles, a characteristic reddening of the root stele, reduced flowering and fruiting, bitter tasting fruit, and plant death. Resistance to red stele in cultivated strawberry and virulence of P. fragariae have been shown to conform to a gene-for-gene model. Genetic resistance against this pathogen is conferred by a series of single dominant Rpf genes that provide race specific resistance among strawberry cultivars. Amplified fragment length polymorphism (AFLP) markers linked to four Rpf resistance genes (Rpf1, Rpf2, Rpf3, and Rpf6) were detected using bulk segregant analysis (BSA). The bulked DNAs represented subsets of three F1 populations segregating monogenically for resistance or susceptibility to specific races of P. fragariae. The map of these Rpf loci was generated using JoinMap with a LOD score of 5. Markers tightly linked to the Rpf1, Rpf3, and Rpf6 genes at distances ranging from 1.7 cM to 5 cM were revealed. The AFLP markers will be converted into sequence characterized amplified region (SCAR) markers as was done with a previously reported RAPD marker for Rpf1. The markers linked to resistance genes will provide an efficient means to screen and select plant material for the presence of resistance genes (marker-assisted selection) as well as to pyramid these genes into single genotypes. |