Genetic improvement of eucalypts

Abstract

Eucalypts are virtually endemic to Australia, are the tallest flowering plants on earth and the most widely planted hardwood plantation species. No sector of world forestry has expanded as rapidly as the industrial use of eucalypts and while they are still at the early stages of domestication compared to crop species, they are fast becoming amongst the most advanced genetic material in forestry. This article overviews (i) the unique biological features of the genus, including its distribution and taxonomy, breeding systems and natural regeneration mechanisms; (ii) the history of its domestication, from its first discovery in the late 18th Century, rapid dispersal around the world in the 19th Century to its prominent role in the industrial plantations of the late 20st Century for the pulp and paper markets; (iii) the genetic improvement of species, from provenance selection to advanced generation breeding strategies, including definition of breeding objectives and large scale assessment of key biological traits affecting profitability; (iv) the important role played by eucalypt hybrids, particularly in tropical and sub-tropical zones; (v) deployment options through seed and clonal propagation systems; and (vi) progress towards molecular breeding and genetic engineering