CONSTRUCTION OF A HIGH FIDELITY GENETIC LINKAGE MAP USING AFLP AND SSR MARKERS IN RAPESEED (Brassica napus L.)

High-density and high-quality genetic linkage maps are valuable tools for genome-wide analyses. In this study, a high fidelity genetic linkage map has been developed in an F1DH population generated from a cross between the winter and spring type rapeseed. The map contained 568 genetic loci covering 2003 cM of the rapeseed genome, with an average markers density of 2.77 cM. The linkage groups represented A1 to A10 and C1 to C9 of the rapeseed genome with the exception of C6, which could not be identified. The failure to map the C6 chromosome might be due to the presence of a reciprocal translocation between homeologous segments of A7 and C6 chromosomes, since the genetic mapping population was developed from the cross between spring and winter type rapeseed. About 17% of SSR primer pairs amplified more than one polymorphic locus. This should be considered as a minimum level of homology analysis in the rapeseed genome. From 40 duplicated loci, 38 duplications were between the A and C genome showing a high level of similarity between the homoeologous A and C genomes. An obvious evidence for homoeology was observed between A1-C1, A3-C3, A9-C9 and between A10-C9 of the rapeseed genome.