INHERITANCE OF INITIAL SURVIVAL AND ROOTING ABILITY IN EUCALYPTUS-GLOBULUS LABILL STEM CUTTINGS

Additive genetic variances and covariances and their corresponding her itabilities and genetic correlations were estimated for the initial su rvival of Eucalyptus globulus LABILL. Stem cuttings (in the propagatio n environment) and the rooting ability of the survivors. Cuttings were harvested on four occasions from 494 clones of 10 full-sib families. Percentage survival of cuttings was moderately heritable, with an esti mated overall heritability of h(2)=0.20, whereas the percentage of sur vivors which rooted had a higher estimated heritability (h(2)=0.41). T here were no genetic or phenotypic correlations between these traits ( r(g)=-0.12 and r(p)=-0.02, respectively). The magnitude of the genotyp e-occasion interaction was marked for survival (P<2%) but small and no t significant for rooting (P>50%), These results indicate that genetic improvements of propagation characteristics in E. globulus could be m ade, and that survival and rooting ability of the survivors should be assessed separately. Selection accuracy appeared to increase with high er overall levels of survival and rooting.