1. CSIRO Plant Industry, North Ryde, NSW 2113, Australia.
2. University of Western Sydney, Faculty of Agriculture and Horticulture, Richmond, NSW 2753, Australia.
3. Cooperative Research Centre for Quality Wheat, Locked Bag No 1345, PO, North Ryde, NSW 3112, Australia.
4. Joint Centre for Crop Improvement, Department of Agriculture, University of Melbourne, Vic 3052, Australia.
5. CSIRO Plant Industry, Canberra, ACT 2600, Australia.
6. Corresponding author. E-mail: c.wrigley@pi.csiro.au Phone: 612 9490 8401. Fax: 612 9490 8419.