Plant Genome IV Conference Plant Genome IV Conference
QTLs have been reported in various forest tree species. Many of these studies involve single full-sib families. Therefore, little information is available on the detection of QTLs in different genetic backgrounds, when the same parent is involved. To try and address this question, we selected a half-sib array of four large (N > 100) full-sib families which have the same Eucalyptus urophylla maternal parent. The families represent intraspecific (E. urophylla X E. urophylla), interspecific (E. urophylla X E. urophylla), and species backcross type (E. urophylla X (E. grandis X E. urophylla) populations. RAPD markers were used to generate genomic maps for the maternal and paternal parents. Phenotype data for tree height, diameter at breast height under bark, wood density, and bark thickness was collected from 5.5 year old trees and used for QTL analysis. Single genomic regions (vigor QTL) affecting the biomass traits have been detected in two of the families. QTL affecting bark thickness and wood density have also been detected. Data on the detection of these loci in different genetic backgrounds will be presented.