Abstract:
The status of genomics and genetics research in
the Myrtaceae, a large family of dicotyledonous woody
plants, is reviewed with Eucalyptus as the focal genus.
The family contains over 5,650 species in 130 to 150
genera, predominantly of neo-tropical and Southern
Hemisphere distribution. Several genera are well known for their economic importance worldwide. Myrtaceae are
typically diploids with small to intermediate genome size.
Microsatellites have been developed for several genera while
higher throughput marker systems such as diversity arrays
technology and single nucleotide polymorphism are available
for Eucalyptus. Molecular data have been fundamental to current perspectives on the phylogeny, phylogeography and
taxonomy of the Myrtaceae, while numerous studies of genetic
diversity have been carried out particularly as it relates to
endangered, rare, fragmented, overharvested or economically
important species. Large expressed sequence tag collections for
species of Eucalyptus have recently become public to support
the annotation of the Eucalyptus grandis genome.
Transcriptomics in Eucalyptus has advanced by microarrays
and next-generation sequencing focusing on wood development.
Linkage maps for Eucalyptus display high synteny across
species and have been extensively used tomap quantitative trait
loci for a number of traits including growth, wood quality,
disease and insect resistance. Candidate gene-based association
genetics have successfully found marker–trait associations for
wood and fiber traits. Genomic selection experiments have
demonstrated clear potential to improve the efficiency of breeding
programs while freeze-tolerant transgenic Eucalyptus trials
have recently been initiated. The recently released E. grandis
genome, sequenced to an average coverage of 8×, will open up
exceptional opportunities to advance Myrtaceae genetics and
genomics research.
