We examined genome-wide patterns of DNA sequence diversity and divergence among six
species of the important tree genus Eucalyptus and investigated their relationship with genomic
Using c. 90 range-wide individuals of each Eucalyptus species (E. grandis, E. urophylla,
E. globulus, E. nitens, E. dunnii and E. camaldulensis), genetic diversity and divergence were
estimated from 2840 polymorphic diversity arrays technology markers covering the 11 chromosomes.
Species differentiating markers (SDMs) identified in each of 15 pairwise species
comparisons, along with species diversity (HHW) and divergence (FST), were projected onto
the E. grandis reference genome.
Across all species comparisons, SDMs totalled 1.1–5.3% of markers and were widely distributed
throughout the genome. Marker divergence (FST and SDMs) and diversity differed
among and within chromosomes. Patterns of diversity and divergence were broadly conserved
across species and significantly associated with genomic features, including the proximity
of markers to genes, the relative number of clusters of tandem duplications, and gene
density within or among chromosomes.
These results suggest that genomic architecture influences patterns of species diversity and
divergence in the genus. This influence is evident across the six species, encompassing diverse
phylogenetic lineages, geography and ecology.