Crosses recommendation method for obtaining Eucalyptus spp. hybrids assisted by molecular markers

Abstract

The genetic and morphological diversity among parents selected in progeny tests of Eucalyptus grandis and E. urophylla was used as a criterion to choose the best crosses for a circulant partial diallel design. In a first stage, 127 parents were selected from 503 clone trees (70 E. urophylla and 57 E. grandis trees) considering two traits: the Mean Genetic Distance (MGD) values obtained by RAPD markers and Annual Mean Increment (AMI) values. In a second stage, these parents were analyzed with other RAPD markers and grouped by the Tocher method. These groups were used to prepare a diallel set, involving the two most divergent groups of parents of the species. Other silvicultural data were used to calculate the average Euclidean distances, which also emphasizes the great variability existing among and within populations. Correlations between the genetic distances obtained by RAPD markers and the average Euclidean distances were negative or very low.