High speed gene mapping can improve Teratosphaeria disease resistance in Blue gum.
This FWPA-funded research used newly developed genome sequencing techniques to find trees in large populations of plantation Blue gum (Eucalyptus globulus) in Tasmania and Western Australia that have genetic differences (i.e. alleles) that give them resistance to Teratosphaeria leaf disease (TLD).
The genetic sequencing process, Marker-assisted selection (MAS), will accelerate breeding programs by allowing breeders to screen large numbers of trees to identify better parental genotypes for crossing and superior genotypes arising from crosses. Thus reducing the timeframe for identifying superior cultivars and the associated operational costs in not growing inferior material.
The incidence of TLD (a type of fungi) is increasing, particularly in plantations due to trees being of uniform age and having a reduced genetic diversity. As resistance to TLD has moderate to strong genetic component, selecting the trees with the most resistant genes has an important economic advantage for tree breeders and growers.
Using the MAS process, the research team found 69 genetic markers that were significantly associated with TLD resistance, with each marker indicating a small increase in a tree’s resistance to the disease. Trees with more markers were more resistant to the disease. Such results suggest that TLD resistance is complex with many genes contributing to the resistance.
Markers identified in this very successful study can be combined with markers developed for other commercial traits, such as wood quality and growth, to select tree lines that contain favourable alleles for other traits.
A webinar presentation on the report and it findings will be held on 5 April.