Objective To study the genetic diversity of Eucalyptus cloeziana for the purposes of germplasm conservation and breeding potential evaluation.

Method Fourteen simple sequence repeats (SSR) markers were used to detect the variation in four main distribution areas of E. cloeziana. The locus polymorphism and population diversity were analyzed, the differentiation coefficient and genetic similarity among regions and the molecular variance components inter-and intra-regions were calculated. Cluster analysis was conducted based on genetic similarity.

Result A total of 249 alleles were detected in 14 SSR markers, with an average of 18 alleles per marker. Based on all the markers, the Shannon's information index was 1.785 4, the observed heterozygosity was 0.510 0, and the expected heterozygosity was 0.788 2, indicating a high genetic diversity. The average coefficient of genetic differentiation among regions was 0.071 6, and the component of variance among populations in analysis of molecular variance (AMOVA) was only 6.8%. This indicated that the level of genetic differentiation was moderate and genetic variation mainly exists in populations. Unweighted pair group method with arithmetic (UPGMA) clustering analysis divided the four main distribution areas of E. cloeziana into two major categories:north and south.

Conclusion The germplasm resource conservation should give priority to the areas with high diversity. The genetic diversity of E. cloeziana is high, and it has great potential for breeding.