GENETIC RELATIONSHIPS AMONG 40 SPECIES OF EUCALYPTUS BASED ON SIMPLE SEQUENCE REPEAT MARKERS

Abstract

Characteristics of genetic sequences across 40 Eucalyptus and Corymbia species, and across individuals within species, were examined based on 20 simple sequence repeat (SSR) loci. Variation of target sequences between species were mainly due to differences in the numbers of repetitions and base mutations on the associated flanking region sequences, whilst variations between individuals within species were mainly due to differences within the repetitive SSR motifs. Estimates obtained across the species examined in this study for indices of genetic diversity, including average expected heterozygosity of 0.48 and average polymorphism information content value of 0.73, were generally consistent with values published from previous studies focused on either single or limited numbers of eucalypt species. Results from analyses of genetic relationships among the 155 genotypes sampled in this study, particularly genetic distances separating species, could be used to help identify potentially compatible hybrid combinations.