Quantitative genetics of Eucalyptus globulus: Affinities of land race and native stand localities

Genetic variation was examined in a Eucalyptus globulusbase population collection comprising 276 seed lots from 12Australian localities and four land races developed in Europeand South America. Thirty variables collected over a 4-yearperiod from four field trials in Argentina representing growth,relative bark thickness, tree form, transition to adult foliageand pilodyn penetration were used to determine the quantita-tive genetic affinities of the populations. The patterns ofquantitative genetic differentiation were summarised usingcanonical discriminant and cluster analyses. Tasmanian andVictorian native stand localities were clearly genetically differ-ent. Land race samples were variable but generally had closeraffinities to native stand localities from southern Tasmania.Portuguese selected full sibs families were the fastest growing,even faster than OPprogeny with the same parents presum-ably due to inbreeding depression after partial selfing. Manynative stand localities were superior in growth to land racematerial. The only consistent genetic difference found betweenland race and native stand material was in tree form at twosites. The generally better form of land race samples is mostlikely due to artificial selection. Large gains in both growthand wood density can be simply achieved by using materialfrom appropriate native provenances.