Molecular analysis of an interspecific hybrid ornamental eucalypt for parental identification

Abstract

The parentage of ‘Urrbrae Gem’, an ornamental hybrid Eucalyptus, was investigated using RAPD-PCR. The female parent was known to be E. erythronema var. erythronema but previous opinion, based on adult morphological characters, placed the male parent as either E. stricklandii or E. gomphocephala. Samples of DNA, extracted from leaves of different individuals within each species, were amplified with six different 10-mer primers to produce RAPD fingerprints. These were used to generate a UPGMA dendrogram based on genetic similarities, and an ordination plot, derived by multi-dimensional scaling (MDS), and minimum spanning tree (MST) to show the relative dissimilarities between the individuals tested. The UPGMA dendrogram divided the samples into three clusters, with the hybrid slightly closer to E. stricklandii than E. gomphocephala. The MDS ordination and MST placed the hybrid between E. erythronema var. erythronema and E. stricklandii, supporting E. stricklandii as the male parent.