Ground Cover Supplement : GC Supplement - Biosecurity
11 BIOSECURITY GROUND COVER DIAGNOSTICS & PRE-BREEDING SPEED TEST A more specific and rapid test for bacteria is the long-term objective but first detailed investigation is required By Deborah Hailstones A SIMPLE DIP-STICK TEST, similar to a pregnancy test, could provide a quick, cost-effective and widely available indicator for the presence of specific bacteria. To develop such a test, unique 'fingerprints' to accurately identify the bacteria are required. Current DNA-based tests are able to provide relatively rapid identification of some bacteria, but these are not able to differentiate between bacterial strains, so a further bioassay is required. This research, being undertaken by the Cooperative Research Centre for National Plant Biosecurity (CRCNPB), is investigating the set of proteins encoded by the genome in different strains of Xanthomonas bacteria. These bacteria cause a range of diseases across several crop species, including bacterial blight of barley and bacterial leaf blight of rice. The secretions required to break through the protective cells of a cotton plant will differ from those required to infect barley, providing a means to discriminate the bacterial strains involved. Proteomics identifies these differences and then the genes that are responsible for encoding these specific proteins can be traced and used as the basis of a more specific DNA-based test. By identifying the molecules the bacteria produce for a range of purposes it is hoped that 'signatures' of infection by particular strains of bacteria can be established. Using these detailed molecular techniques could lead to tests that provide a more definitive diagnosis within 12 hours, rather than the best-case scenario of four days using current bioassays. These tests will be used by laboratory staff to identify bacterial strains, facilitating market access and optimising disease management and response. □ Research Code: CRCNPB project -- the GRDC is a partner in the CRCNPB More information: Dr Deborah Hailstones, project leader plant bacteria platforms, Science and Research, I&I NSW and CRCNPB, 02 4640 6442, email@example.com BORDER SECURITY FOR VIRUSES Molecular tests are helping AQIS to more accurately identify viruses in imported plant material By Brendan Rodoni EACH YEAR IT is estimated that plant breeders ship more than 23 tonnes of wheat germplasm around the world. All seed arriving in Australia is quarantined and assessed by the Australian Quarantine and Inspection Service (AQIS) for pests and diseases, but virus symptoms can be hard to identify. Through a project funded by the Cooperative Research Centre for National Plant Biosecurity and the Victorian Department of Primary Industries, with support from the GRDC and AQIS, molecular tests for viruses are being developed. Now midway through the second phase of research, this project has worked with AQIS to validate molecular tests that have the potential to detect many of the known grain viruses. These include tests for five of the 22 viruses listed under Australia's Emergency Plant Pest Response Deed. An example of such a virus is wheat spindle streak mosaic virus, which enters the soil via a soil- borne fungus. It is hard to kill and is certainly a virus that we do not want introduced to Australia. Currently, imported seed is planted in post-entry quarantine facilities and the resulting plants are visually assessed for virus symptoms. The new tests will provide greater security against viruses due to more specific and accurate identification. This will help prevent breeding material being withheld due to the suspicion of viral contamination and increase the biosecurity of the seed lines that are imported into Australia. The new testing protocols were tried on 450 cereal lines from the Industry & Investment New South Wales collection housed at Tamworth. All proved to be free of these viruses and no false positives were detected. The tests will also help build on the gains already made in horticulture quarantine processes, such as the reduction in approval time for new apple cultivars from three years to 18 months. As the developed tests for the high-risk viruses are molecular-based, it may be possible to screen for multiple breeding traits at the same time using DNA markers and before the germplasm enters Australia. The research team is now working with virologists in the US, Canada and New Zealand to ensure the same testing procedures are used by our main germplasm trading partners. □ Research Code: CRCNPB project -- the GRDC is a partner in the CRCNPB More information: Dr Brendan Rodoni, Victorian Department of Primary Industries, 03 9210 9264, firstname.lastname@example.org Molecular tests are being developed to improve detection of exotic bacteria and viruses that could be travelling on imported grain. Molecular techniques are being developed to provide more rapid and assured means of identifying the presence of bacteria and viruses that may be contained in seed. TESTS HAVE THE POTENTIAL TO DETECT MANY OF THE KNOWN GRAIN VIRUSES.
GC Supplement - Capacity building
GC Supplement - Grain storage