Identification of races in Eucalyptus globulus ssp globulus based on growth traits in Tasmania and geographic distribution

Abstract

Canonical discriminant analysis of 432 open-pollinated families grouped into 46 collection localities covering the natural geographic range of Eucalyptus globulus ssp globulus was carried out on four year growth data from five trial sites in Northern Tasmania. Combining results from the analysis of growth responses with natural geographic boundaries and reported taxonomic groupings it was possible to identify 12 geographical races in the E. globulus ssp globulus base population. The three races from Victoria [(1) the Otway Ranges, (2) the Strzelecki Ranges and (3) South Gippsland], the (4) King Island, the (5) Furneaux Group, and (6) Central Western Tasmania races, showed relatively similar growth responses. Races from eastern Tasmania, [ (7) Northeastern Tasmania, (8) Eastern Tasmania, (9) Jericho, and (10) Southeastern Tasmania] were distinct from the previous large group. Two small races, (11) Port Davey and (12) Lighthouse, Wilson's Promontory had very slow growth. The trees at the Lighthouse locality had a distinct shrub-like habit. The classification of four localities (South West Lavers Hill, Clarke Island, Dover and Recherche Bay) was doubtful. The variation in growth response across environments among the different races suggest that appropriate genetic groupings (tentatively the 12 geographic races identified here) should be made prior to further genetic analysis of E. globulus ssp globulus breeding populations.