Boneseed Rust: A highly promising candidate for biological control

Citation

Land & Water Australia. 2008. Boneseed Rust: A highly promising candidate for biological control. [Online] (Updated April 28th, 2009)
Available at: http://lwa.gov.au/node/2572 [Accessed Tuesday 26th of April 2011 01:34:45 AM ].

Summary

This project investigated the use of Endophyllum osteospermi (a systemic rust fungus) in the biological control of boneseed (Chrysanthemoides monilifera ssp. monilifera). This systemic South African rust fungus has been found to reduce growth and the reproduction of plants by causing extensive deformation of infected branches (witches’ broom).

Boneseed is a Weed of National Significance, which occurs mainly in Victoria, South Australia and Tasmania.

Aims

This project aims to complete the host-specificity testing phase of the boneseed rust to provide the necessary data to finalise the risk assessment for this rust and build a strong case to support its release in Australia. This will be achieved by:

Carrying out inoculations of the six non-target plant species on which penetration occurred in initial host-specificity tests, and microscopically examining samples taken 4 weeks after inoculation to determine if the rust has successfully colonised plant tissue. (Modified objective proposed to L&W Australia in March 2007 and accepted on 7 June 2007)
Preparing and submitting an application to release the rust to the regulatory authorities.
Developing a molecular-based tool to enable detection of the rust in symptomless plants after release since it can takes up to 2-3 years for visible disease symptoms to develop.
Negotiating with AQIS to determine an acceptable approach to release the rust from the quarantine facility.

Outcomes

This project has generated new approaches to the establishment and detection of boneseed rust that will play important roles in future development of biological control agents for boneseed. Through the adaptive approach to the research and appropriate applications to AQIS, the Principal investigator has also achieved innovative new approaches to tge use of traditional 3-tiered host specifity esting for biocontrol agents. Each of these new aspects of knowledge may have applications beyond the specific case under study - rust fungus control of boneseed.