Development and testing of new gene-homologous EST-SSRs for Eucalyptus gomphocephala (Myrtaceae)(1)

• Premise of the study: New microsatellite (simple sequence repeat [SSR]) primers were developed from Eucalyptus expressed sequence tags (ESTs) and optimized for genetic studies of the southwestern Australian tree E. gomphocephala, which is severely impacted by tree health decline and habitat fragmentation. • Methods and Results: A total of 133 gene-homologous EST-SSR primer pairs were designed for Eucalyptus, and 44 were screened in E. gomphocephala. Of these, 17 produced reliable amplification products and 11 were polymorphic. Between two and 13 alleles were observed per locus, and observed heterozygosities ranged from 0.172 to 0.867. All 17 EST-SSRs that amplified E. gomphocephala cross-amplified to at least one of E. marginata, E. camaldulensis, and E. victrix. • Conclusions: This set of EST-SSR primer pairs will be valuable tools for future population genetic studies of E. gomphocephala and other eucalypts, particularly for studying gene-linked variation and informing seed-sourcing strategies for ecological restoration.