Poster Presentation Science Protecting Plant Health 2017

Pathogenicity of Xanthomonas species causing bacterial leaf spot in Australia (#331)

Rebecca Roach 1 2 , Rachel Mann 2 , Cherie G Gambley 3 , Roger G Shivas 1 , Brendan Rodoni 2
  1. Department of Agriculture and Fisheries, Ecosciences Precinct, Brisbane, QLD, Australia
  2. Department of Environment and Primary Industries, La Trobe University, Bundoora, QLD, Australia
  3. Department of Agriculture and Fisheries, Applethorpe Research Facility, Stanthorpe, QLD, Australia

Bacterial leaf spot in Australian solanaceous crops is caused by at least five Xanthomonas species. Isolates of Xanthomonas associated with bacterial leaf spot were identified using molecular and biochemical analyses. The species diversity revealed in this study indicates disease severity could vary with causal species and location.  

Pathogenicity trials were conducted to assess the impact of the collected isolates on crops. The ability of these pathogens to overcome established host resistance genes and chemical treatments was assessed. Race and copper tolerance scores were assigned to the collected Xanthomonas isolates to determine potential disease severity on hosts and efficacy of current control methods. The need for varieties with the full suite of BLS resistance genes is highlighted. Determining the variation of the pathogenic capability of these species will lead to improved detection and identification of the Xanthomonas species associated with bacterial leaf spot in Australia. The potential for alternative control methods, future management strategies and the detection of exotic Xanthomonas species will be discussed.