Looking at the 'good guys'

By Emma Leonard

Disease-causing organisms have long been the research domain of the Crop Pathology Unit at the South Australian Research and Development Institute (SARDI). Now SARDI is broadening its focus from detecting and managing soil-borne pathogens to encompass the rest of the soil microflora.

Dr Kathy Ophel-Keller, leader of the SARDI Crop Pathology Unit, says: “We need to think about pathogens in the environment in which they live – not only their interaction with the plant host and environmental conditions, but also with the complex environments of soil and around plant roots.”

The GRDC Soil Biology Initiative is funding two projects that are part of the unit’s broader vision. SARDI researcher Dr Steve Barnett is leading a project to identify microorganisms involved with disease suppression. He has identified three soil bacteria which are involved with the suppression of the diseases Rhizoctonia, take-all and Fusarium crown rot.

“We know there are other soil organisms, such as actinomycetes and fungi, which are important in the suppression of these diseases and over time we hope to have a solid understanding of the key organisms controlling this disease suppression,” he says.

The second project is a collaboration between SARDI, the Shandong Academy of Sciences, in China, and CSIRO Land and Water. In this, the researchers are testing some of these disease suppressive organisms for their potential as inoculants that protect against disease outbreaks. Dr Ophel-Keller says, “The longer term goal of the unit is to learn how to manage farming systems to favour beneficial rather than pathogenic organisms.

It may be possible to use SARDI’s powerful DNA diagnostic technology [developed in collaboration with CSIRO Entomology] to develop monitoring tools not only for pathogens, as used in the PreDicta B® soil tests, but also for beneficial microflora.

“We hope one day farmers will be able to access a comprehensive service to monitor both pathogens and beneficial organisms so they can see how their crop management is relating to their soil. Such a service would build on the groundbreaking technology of the root-disease testing which Australian farmers are the first in the world to use.”

For more information:
Dr Kathy Ophel-Keller, SARDI, 08 8303 9368, ophelkeller.kathy@saugov.sa.gov.au

GRDC RESEARCH CODES DAS00027 & DAS00036, program 4