Linkage maps of Eucalyptus globulus using RAPD and microsatellite markers

The construction of linkage maps based on RAPD markers using an F1 intraprovenance cross in Eucalyptus globulus subsp. globulus is reported. Twenty-one microsatellite loci originating from E. globulus and four other Eucalyptus species were added to the RAPD maps. Linkages between microsatellites previously reported for E. grandis/E. urophylla were found to be conserved in E. globulus allowing confident assignment of homology for several linkage groups between maps of these species. Homology was also identifiable between most linkage groups of the two E. globulus parents based on microsatellites and RAPD loci segregating from both parents. At a LOD score threshold of 4.9 the male parent has 13 linkage groups covering 1013 cM with 101 framework markers ordered at LOD 3.0. The female parent has 11 linkage groups covering 701 cM with 97 framework markers. On the female map there were more regions of segregation distortion than expected and genetic mechanisms to explain distorted segregation are discussed. Several linkages that arise between pairs of E. globulus linkage groups as the LOD score is reduced are supported by interspecific homologies identified using microsatellite loci.