Genetic Improvement ofEucalyptus amplifoliafor Frost-Frequent Areas

Abstract

Summary Sixty-nine Eucalyptus amplifolia seedlots (four previously tested provenances and 65 half-sib progenies from selected trees in 11 Australian provenances) were established in September 1986 at Gainesville, Florida, measured periodically for growth and frost-tolerance, and converted in August 1989 to a seedling seed orchard on the basis of sib and individual superiority. Provenance variability was significant for seedling and second-coppice survivals but especially for frost-tolerance. The provenances represented by the 65 progenies were notably better than previously tested provenances. No new provenance was superior in all critical traits, but each had at least one progeny with good tree size and acceptable frost-tolerance. Individual and family heritabilities were moderate, and seedlings from the seed orchard should have about 30% better growth and frost-tolerance. Selected progenies also performed well in additional field studies. The resilience of E. amplifolia progenies in a freezing chamber t...