Marker-trait associations for survival, growth, and flowering components in Eucalyptus cladocalyx under arid conditions

Understanding the basis of the genetic variations responsible for the complex traits found in Eucalyptus cladocalyx under arid environmental conditions is crucial for designing genetic architecture studies. Forty-five half-sib families from Australia were used to identify inter-simple sequence repeat (ISSR) markers that are associated with growth (height, diameter at breast height, and stem straightness), flowering traits (flowering intensity, flowering precocity, reproductive capacity, and late flowering) and tree survival under arid conditions in southern Atacama Desert, Chile. Each DNA pellet consisted of a pool of five trees from each family. ISSR markers were associated with all the traits studied and accounted for 9.8 to 23.4 % of the phenotypic variation. Several loci were associated with more than one trait. For example, UBC810(450-500 bp), ISO1(600-610 bp), and TGT(9(780-800 bp)) were associated with three of the traits studied. These identified genomic regions may contribute to the increase of the efficiency of the conventional tree breeding program for E. cladocalyx.