Abstract
To find markers linked to vegetative incompatibility (vic) genes in the chestnut blight fungus,
Cryphonectria parasitica, we constructed a preliminary linkage map. In general, this map is characterized by low levels of polymorphism, as evident from the more than 24 linkage groups observed, compared to seven expected from electrophoretic karyotyping. Nonetheless, we found markers closely linked to two vic genes (vicl and vic2) making them candidates for positional cloning. Two markers were found to be linked to vic2: one cosegregated with utc2, i-e., it is 0.0 cM from vic2, the other was at a distance of 4.5 cM; a single marker was found 4.0 cM from vicl. The closest markers linked to three other Vic genes (vic4, vic6, and vic7) were >15 cM away; additional markers are needed before efficient positional cloning of these three vic genes can be realized. In contrast to the low levels of polymorphism observed across most of the C. parasitica genome, the linkage group containing the MAT locus appears to harbor an extremely high level of RAPD heterogeneity and reduced recombination. Markers within this highly heterogeneous region are in linkage disequilibrium in some natural populations; however, recombination is clearly evident between this region and the MAT locus.
Keywords
chestnut blight,
recombinational linkage map,
RAPD,
SCAR,
EST,
consegregation,
suppressed recombination,
heterogeneity,
linkage disequilibrium
Citation
Kubisiak, Thomas L.; Milgroom, Michael g. 2006. Markers linked to vegetative incompatibility (vic) genes and a region of high heterogeneity and reduced recombination near the mating type locus (MAT) in
Cryphonectria parasitica. Fungal Genetics and Biology, Vol. 43: 453-463
