Development of Species-Specific Markers for the Identification of Eucalyptus

One of the main problems found in different forest breeding programs in Brazil is the difficulty to identify the different species and hybrids. We assessed in a first stage the power of discrimination of markers BSA associated with markers AFLP in five species of Eucalyptus (E. saligna, E. tereticornis, E. urophylla, E. grandis and E. brassiana). As a second strategy we assessed the power of 30 candidate barcodes on the basis of 14 eucalyptus species obtained primarily from Australia. Our results indicated that using AFLP markers and BSA in 33 primer combinations, a total of 868 polymorphic fragments was obtained, which represent a 91.65% of polymorphism. The best combinations that show potential markers for species identification were the primers M + GGT / E + ACC, which was linked to 70% of E. urophylla individuals.Based on DNA-barcode markers “best match” and “best close match” approaches revealed a rate of correct species identification ycf1+ITS+matK (62.16%) followed by matK+ITS (61.64%) loci. Neighbour-joining cluster analysis indicated the highest degree of the 25 possible combinations of the five regions; three provided the highest degree of species resolution (78.6%). The markers BSA associated with markersAFLP provide a quick tool for the identification of cultivars in eucalypts and can also be used to assist forest breeding programs. Based on DNA-barcode markers, a combination of ITS+rbcL, ITS+matK+rpoC1 and ITS+rbcL+rpoC1, which comprises two and three DNA regions, is the best option for barcoding of Eucalyptus species.