Evaluation of perennial wheat germplasm in an Australian environment.

There is interest in developing cereal plants with a perennial habit because of potential advantages in production stability and environmental sustainability. Breeding programs in the northern hemisphere have produced perennial wheats by crossing annual bread wheat lines (Triticum aestivum) with perennial wheatgrasses (Thinopyrum spp.). This study evaluated the performance of 67 of these hybrid derivatives in Australia compared to the annual winter wheat cv. EGA Wedgetail. The experiment was conducted at Cowra in the mixed cropping zone of NSW. All hybrid derivatives were significantly later in their maturity than cv. EGA Wedgetail (mean 123 days after sowing to flowering)(P > 0.05), with 18 of the imported lines yielding as well or better than the control (mean 136.7 g/m row). Most lines containing Th. intermedium or Th. ponticum in their pedigree were highly resistant to wheat streak mosaic virus and most proved very resistant to stripe and leaf rust. Good resistance to current Australian races of stem rust was rare within the germplasm. Nine entries regrew and produced grain in the second season. These lines tended to be lower yielding in the first year. Although potential exists, ongoing research is required to strengthen perenniality, ensuring survival through the harsh Australian summers and guaranteeing adequate grain yields. Significantly, this germplasm is proving a rich resource of disease resistance.