Sclerotinia stem rot (SSR) is a disease of canola caused by the fungus Sclerotinia sclerotiorum, which is known to infect over 400 plant species. It causes direct damage to the canola plant by girdling the stem, leading to lodging. The current estimate of losses incurred by SSR is $10m per annum, making this the second most important fungal disease of any break crop.
S.sclerotiorum is unlike any of the other fungal pathogens studied at the CCDM. The way in which it infects host plants is still not well understood, making it our most challenging pathogen to work with. The main goals for this program are:
- To develop new genetic tools for controlling SSR in canola.
- To determine whether Australian isolates of sclerotiorum behave similarly to other S. sclerotiorum isolates from around the world.
Current and Future Projects
Understanding how Sclerotinia sclerotiorum infects Canola
Do different isolates of S. sclerotiorum have the same level of aggressiveness on different canola cultivars? This is one of the questions we want to answer as it has implications for how canola may resist S. sclerotiorum infection. We will do this by infecting different varieties of canola with different isolates and measuring the level of disease development.
Ultimately, we hope to apply the results to canola breeding. If we can determine what genes in S. sclerotiorum control aggressiveness we will be able to use a combination of traditional and modern technologies to counter them.
Determining the genetic diversity of Australian Sclerotinia sclerotiorum isolates
Starting with Western Australian isolates, our team are in the process of determining the genetic diversity of S. sclerotiorum in Australia. This information will help us to better understand how isolates differ from one another. If they are very diverse there might be implications for how fast they can adapt to new resistant canola cultivars or commonly used fungicides.
Comparing Australian Sclerotinia sclerotiorum isolates to those in other countries
With improved knowledge of Australian Sclerotinia sclerotiorum isolates, the next logical step is to determine whether they differ from isolates in other parts of the world. If they are similar then we may be able to draw the conclusion that results from international studies on S. sclerotiorum are applicable to the S. sclerotiorum isolates that we have in Australia.
To compare our isolates with other countries we need a good S. sclerotiorum reference genome sequence. A reference genome already exists but there are numerous unresolved gaps in the genetic code. Using newer technology we have already started to fill these gaps and hope to complete this in coming months.
Which fungicides control SSR?
We are testing fungicides that are not currently registered to see how effective they are for controlling SSR. The most successful fungicides from our lab studies will be tested in the field. Essentially we want to know how we can most efficiently use resources that are currently available to combat SSR in Australia.
Contact the Team
To contact the Sclerotinia team, click on either team member: