Abstract
A total of 1,110 decamer primers were screened for RAPD markers linked to a dominant allele in hazelnut (
Corylus avellana) that confers resistance to eastern filbert blight caused by
Anisogramma anomnala. Twenty RAPD markers linked in coupling, and five markers linked in repulsion, were found. A seedling population was used to construct a linkage map of the region flanking the resistance locus. The map spans 46.6 cM, with 14 markers on one side of the resistance locus and eight on the other side. Eleven markers showed less than 3% recombination with resistance, including three that showed no recombination. Seven of these 11 markers are sufficiently robust to allow their use in marker-assisted selection. These include AA12
850 which shows no recombination, and six markers on one side of the resistance locus: 173
500, 152
800, l22
825, 275
1130, H19
650, and O16
1250. Marker 268
580, which flanks the resistance locus on the other side, is also suitable for use in marker-assisted selection. but shows 5.8% recombination with resistance. Other markers are less suitable for marker-assisted selection because of sensitivity to changes in primer or MgCl
2 concentration, or the long time required for electrophoresis to separate bands of similar size. The 16 markers closest to the resistance locus were cloned and sequenced. The W07
365 marker, which showed no recombination with the resistance locus but is difficult to score, includes a CT microsatellite repeat. The sequence information will allow the design of SCAR primers and eventual map-based cloning of the resistance allele.
Citation
Mehlenbacher, S.A.; Brown, R.N.; Davis, J.W.; Chen, H.; Bassil, N.V.; Smith, D.C.; Kubisiak, Thomas L. 2004. RAPD markers linked to eastern filbert blight resistance in
Corylus avellana. Theor. Appl. Genet. 108: 651-656