In this section:
Screening Program
The Nematology Group offers screening services on a fee-for-service basis for cereal cyst nematode, root lesion nematode and stem nematode.
- Cereal Cyst Nematode
- Pratylenchus
- Stem Nematode
Cereal Cyst Nematode
The Nematology Group provides two types of assays for screening wheat, barley, oat and triticale lines for resistance to cereal cyst nematode (CCN): the large scale "POTS assay"; and the small scale Controlled Environment Room (CER) assay.
POTS assay - this high-throughput screening service is an outdoor assay, with plants sown into seedling tubes containing soil infested with CCN cysts. Plants are sown in June and assessed in November. At present, the capacity of the POTS assay is approximately 120,000 plants per year with lines replicated between 3 - 20 times (depending on request) and results compared with "check" varieties of known resistance or susceptibility. A database system is used to provide seeding plans and record information for the resistance or susceptibility of each line/variety.
Over 4 tonnes of inoculum are required for this assay which is produced from infected plants retained from the previous season, occasionally supplemented with inoculum from infested field sites to maintain levels of organic matter.
We recommend that this assay is used to determine the resistance rating of early generation breeding material to eliminate/identify lines susceptible to CCN.
CER assay - this screening service is a growthroom assay. Seedlings are inoculated with CCN larvae and plants are assessed 9 weeks after inoculation. While the CER test is more labour intensive than the POTS assay, it is more accurate as all CCN are assessed from the root system and the soil surrounding the plant. At present, the capacity of the CER test is approximately 6000 plants per year. We recommend that advanced lines should be screened using the CER test (prior to release) to confirm/identify their CCN resistance rating.
Within both the POTS and CER assays, we have the capacity to tag and retain resistant plants to produce seed i.e. it is not a destructive test.
Please contact John Lewis if you require further information about either of the CCN screening services or wish to submit lines for evaluation.
Pratylenchus
The Nematology Group provides a screening service for assessing resistance to the root lesion nematodes Pratylenchus neglectus and P. thornei. The screening test for these nematodes is a glasshouse assay. Plant seedlings are inoculated with either P. neglectus or P. thornei and nematode numbers assessed from root systems after 8 weeks. This is a destructive assay i.e. seed cannot be kept from individual plants. Lines are replicated 5 times within each test and results are compared with "check" varieties of known resistance or susceptibility. We recommend lines are screened in a minimum of 2 tests to determine a reliable resistance rating.
At present, the capacity of the screening program for Pratylenchus is a total of 10,000 plants per year (2000 lines) and material is screened for wheat breeding programs in southern Australia.
Please contact Barbara Hall if you require further information about this service or wish to submit lines for screening.
Stem nematode
The Nematology Group provides a screening service for assessing resistance and tolerance of oats or resistance of faba beans to stem nematode (Ditylenchus dipsaci, oat race). This screening assay is an outdoor test, with seedlings inoculated with stem nematode and assessed for tolerance (visual symptoms of damage) or resistance (nematodes extracted and counted from plants) 3-4 months after inoculation.
Lines are replicated between 5-100 times (depending upon request) and results are compared with "check" varieties of known resistance or susceptibility. We recommend lines are screened for a minimum of 2 years to determine a reliable resistance or tolerance rating.
We can retain seed from resistant and/or tolerant plants if requested. At present, we have the capacity to screen approximately 3000 oat and 500 faba bean plants per year and material is currently evaluated for the South Australian oat and faba bean breeding programs.
Please contact Greg Walker if you require further information about this service or wish to submit lines for screening.
