Linkage maps of Eucalyptus globulus using RAPD and microsatellite markers

The construction of linkage maps based on RAPD markers using an F-1 intrapr ovenance cross in Eucalyptus globulus subsp. globulus is reported. Twenty-o ne microsatellite loci originating from E. globulus and four other Eucalypt us species were added to the RAPD maps. Linkages between microsatellites pr eviously reported for E. grandis/ E. urophylla were found to be conserved i n E. globulus allowing confident assignment of homology for several linkage groups between maps of these species. Homology was also identifiable betwe en most linkage groups of the two E. globulus parents based on microsatelli tes and RAPD loci segregating from both parents. At a LOD score threshold o f 4.9 the male parent has 13 linkage groups covering 1013 cM with 101 frame work markers ordered at LOD 3.0. The female parent has 11 linkage groups co vering 701 cM with 97 framework markers. On the female map there were more regions of segregation distortion than expected and genetic mechanisms to e xplain distorted segregation are discussed. Several linkages that arise bet ween pairs off. globulus linkage groups as the LOD score is reduced are sup ported by interspecific homologies identified using microsatellite loci.