A COMPARISON OF GENETIC INFORMATION FROM OPEN-POLLINATED AND CONTROL-POLLINATED PROGENY TESTS IN 2 EUCALYPT SPECIES

Genetic-parameter estimates and parental breeding-value predictions we re compared from open-pollinated and control-pollinated progeny popula tions of Eucalyptus globulus and two populations of E. nitens. For E. globulus there were two types of open-pollinated populations (native s tand open-pollinated and seed orchard open-pollinated) and two types o f control-pollinated populations (intra-provenance and inter-provenanc e full-sib families). For E. nitens there were two populations, a seed orchard open-pollinated population and intra-provenance full-sib fami lies. Progeny tests were established across multiple sites and 2-year height and diameter were measured and volume calculated. Genetic param eters from native stand open-pollinated E. globulus were unlike the pa rameters from the other three E. globulus populations; heritability es timates were severely inflated, presumably due to high levels, and pos sibly differential levels, of inbreeding depression relative to the ot her populations. Estimates of dominance variance in the E. globulus fu ll-sib populations were high, but were zero in the E. nitens populatio n. Correlations among parental breeding values, predicted using data f rom the different populations, were generally low and non-significant, with two exceptions: predictions from the two E. globulus full-sib po pulations were significantly correlated (r=0.54, P=0.001), as were pre dictions from the E. nitens seed orchard OP and full-sib population (r =0.61, P=0.08). There was some indication that superior parents of E. globulus native stand open-pollinated families also tended to have abo ve-average breeding values based on the performance of intra-provenanc e full-sib offspring. The consequences of these results for exploitati on of base-population collections from native stands are discussed.