Disease patterns will vary with a changing climate presenting new challenges for cereal scientists. In this scenario, identifying resilient cereal germplasm that combines both high yield and disease resistance will be vital. The CAIGE (CIMMYT-AUSTRALIA-ICARDA Germplasm Evaluation) concept has proven to be an effective way for Australian cereal breeders, pre-breeders and pathologists to optimise the use of wheat and barley genetic resources from the wheat and barley programs of the Consultative Group on International Agricultural Research (CGIAR). The Australian Grains Research and Development Corporation (GRDC) supports this multi-partner collaborative program with international and Australian partners including public pathology programs, universities and private breeding sector companies. CAIGE, led by the University of Sydney, coordinates the selection, importation and quarantine (provided by the Australian Grains Genebank), multiplication, and assessment of the international crop germplasm (bread wheat, durum wheat and barley) in Australia, including concurrent testing for important foliar and soil borne pathogens. CAIGE manages the information generated using a relational database and disseminates the information through our website (caigeproject.org.au).
CAIGE provides information for Australian scientists, breeders, and pre-breeders to optimise the selection of germplasm with novel resistance genes within high yield adapted genetic backgrounds. A key focus of this work has been a wholistic evaluation of resistance against multiple pathogens. With bread wheat more than ten valuable high yielding wheat lines from the International Centres CIMMYT and ICARDA have been identified across the main cereal cropping regions of Australia. These lines have confirmed multiple pathogen resistance to three or more pathogens including stripe/yellow (Puccinia striiformis f. sp. tritici), leaf rust (P. triticina) and stem rust (P. graminis f. sp. tritici), Septoria nodorum blotch including both leaf and glume (Parastagonospora nodorum) Septoria tritici blotch (Zymoseptoria tritici), yellow spot/tan spot/yellow leaf spot (Pyrenophora tritici-repentis), powdery mildew (Blumeria graminis f. sp. tritici), and soil borne pathogens including root lesion nematode (Pratylenchus thornei and/or P. neglectus) and crown rot (Fusarium pseudograminearum).
Similarly, more than 80 international barley lines from ICARDA have been identified as having resistance to three or more economically important pathogens including root lesion nematodes (Pratylenchus neglectus and/or P. thornei), net form net blotch (Pyrenophora teres f. teres), spot form net blotch (P. teres f. maculata), spot blotch (Cochliobolus sativus), barley leaf rust (Puccinia hordei), stem rust (P. graminis) and scald (Rhynchosporium secalis). Of these 80 lines, 54 are in adapted backgrounds and 26 are landraces.
It is likely that some of these cereal disease resistances will be novel as the imported materials generally have genetic diversity not present in Australian germplasm and are providing opportunities to expand the Australian cereal gene pool. Preliminary work using molecular tools with known disease resistance markers for several pathogens have inferred novel resistances for some of the lines. These lines provide significant value to the Australian breeding community, our international partners and may also prove to be useful for other programs around the world, as may the CAIGE model of germplasm exchange and collaboration.