Provenance variation, genetic parameters and potential gains from breeding for biomass and cineole production in three-year-old<i>Eucalyptus loxophleba</i>subsp.<i>lissophloia</i>progeny trials

Abstract

Mallee eucalypts are being domesticated for use as a perennial biomass crop for dryland agriculture in southern Australia. Nine provenances of Eucalyptus loxophleba subsp. lissophloia were tested in trials at Brookton, Western Australia, Monarto, South Australia, and Condobolin, New South Wales. Provenance rankings for biomass production were more similar between Brookton and Condobolin than between Monarto and the other sites. Provenances Mt Walker and Yellowdine ranked amongst the top three performers on all three sites. Type B genetic correlations between pairs of sites ranged from r = 0.13 to r = 0.67, suggesting significant genotype x environment interaction amongst sites. Heritability (ĥ2) for biomass productivity on the three sites was 0.19 ± 0.05, 0.13 ± 0.04 and 0.25 ± 0.05 for Monarto, Condobolin and Brookton respectively. Heritability of leaf cineole concentration at Brookton was 0.53 ± 0.07. Gains from selection scenarios treating the three trials as separate regions gave the highest gain in biomass productivity, whilst treating all three sites as one region resulted in about 6% lower gain. Leaf cineole concentration is a useful selection criterion in the absence of data for total mass of cineole produced per tree.