European blackberry, a group of closely related species belonging to the Rubus fruticosus aggregate (Rosaceae), is an introduced invasive shrub of agriculture, forestry and natural ecosystems in Australia. This chapter describes the various Australian biological control projects targeting European blackberry carried out over the years and summarises similar efforts undertaken in other countries. Surveys in Europe in the 1970s identified three potential agents for European blackberry, the stem-boring sawfly Hartigia albomaculata, purple blotch fungus Septocyta ruborum and leaf-rust fungus Phragmidium violaceum. The purple blotch fungus was not investigated at the time and preliminary host-specificity tests with the sawfly showed that larvae were able to feed on a number of cultivated blackberry and rose varieties. In 1984, while efforts were underway in Europe to select isolates of the leaf-rust fungus, it was found in Australia after an unauthorised introduction. Nonetheless, one of the selected and tested isolates (Fl5) was officially released in Australia in the early 1990s. Subsequent research addressed knowledge gaps considered critical to the biological control success of European blackberry, including a taxonomic revision of the R. fruticosus aggregate in Australia, climate modelling to predict impact of the rust fungus, and studies of pathogenicity and population genetics of the fungus to explain variation in disease intensity across the landscape. In 2000, eight additional and genetically diverse isolates of the rust fungus were sourced using a trap garden established in Europe that comprised blackberry clones from Australia. Following demonstration of host-specificity and approval for release in 2004, a large scale release program, including re-release of F15, was established and the fate of the additional isolates monitored using molecular markers. Concurrently, surveys for other potential candidate agents were performed in Europe and as a result the purple blotch fungus is being investigated in more detail.

Item Type:	Research Book Chapter
Keywords:	Rubus systematics, leaf-rust fungus, Phragmidium violaceum, sawfly, Hartigia albomaculata, purple blotch fungus, Septocyta ruborum
Research Division:	Agricultural and Veterinary Sciences
Research Group:	Crop and Pasture Production
Research Field:	Crop and Pasture Protection (Pests, Diseases and Weeds)
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Forestry
Objective Field:	Forestry not elsewhere classified
Author:	Evans, KJ (Dr Katherine Evans)
ID Code:	63146
Year Published:	2012
Deposited By:	Agricultural Science
Deposited On:	2010-04-15
Last Modified:	2017-04-20
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