Summary

Since 2007 ginger growers in Australia have faced significant crop losses due to soft rot disease caused by Pythium. Pythium myriotylum had been identified as causing this rot however our recent studies indicate that there is more than one species present, possibly including P. Zingerberis which is thought to be specific to ginger. It is important to determine what Pythium species are prevalent and what their host range is as this will determine plans for control via containment or crop rotation.

We propose collecting numerous Pythium isolates from ginger fields and identifying those that are capable of infecting ginger and then assessing them at the molecular and taxonomic level and the assessing the host range using pot plant trials in the glasshouse as well as seedling assays in growth cabinets. This will allow us to determine if indeed there is more than one species (or more than one distinct strain of P. myriotylum) affecting ginger. Comparison with overseas collections will be made, this may only be possible with DNA as cultures may not be permitted by DAFF-Biosecurity to be brought into the country.

We then need to determine if these putative different species/strain show differing levels of pathogenicity to ginger and if they have different host ranges. If this is the case it will then be important to monitor where the more aggressive strains are presently located so as to minimise spread. Host range studies will allow determination of suitable crops to use to reduce disease levels.

Program

Ginger

Research Organisation

The University of Queensland

Objective Summary

1. Identify the range of pathogenic species causing Pythium soft rot in ginger fields in Australia
2. Determine the host range of the predominant Pythium genotypes for implementation of recommendations of crop rotations
3. Assess distribution of aggressive genotypes with a view for recommendation on containment / management practices