June 10, 2003

CSIRO Plant Industry

Barley yellow dwarf virus (BYDV) is the most damaging cereal virus in the world and can cause yield losses in Australian barley, oats and wheats as high as 40-50 per cent. CSIRO Plant Industry plant breeders have used a wild grass to produce what may be the world’s first barley yellow dwarf virus resistant wheat variety.

Over the past fifteen years, CSIRO plant breeders have worked with Chinese researchers to screen wild grasses that were close relatives of wheat, in search of a BYDV resistant strain. They found several, but had to come up with creative methods of breeding the resistance trait into commercial wheat lines.

By growing plant cells rapidly in an unorganised callus mass—a process that induces a high rate of chromosome exchange—researchers generated thousands of potentially resistant plants. From these plants five or six were shown to have the BYDV resistance trait and were bred into spring and winter wheats.

Mackellar is the first of the new resistant varieties to be available commercially, with early trials showing a 26 per cent yield increase under standard field conditions. Mackellar is a dual-purpose winter wheat that also has very good resistance to stem, leaf and stripe rust.

Named after the poet Dorothea Mackellar, the variety is being launched by AWB Seeds throughout 2003.

More information

Mackellar - virus beating wheat

CSIRO Plant Industry plant breeders have used a wild grass to produce Australia's first barley yellow dwarf virus resistant wheat variety.

Barley yellow dwarf virus (BYDV) is the most damaging cereal virus in the world and can cause yield losses in Australian barley, oats and wheats as high as 40-50 per cent. CSIRO Plant Industry plant breeders have used a wild grass to produce what may be the world's first barley yellow dwarf virus resistant wheat variety.

Over the past fifteen years, CSIRO plant breeders have worked with Chinese researchers to screen wild grasses that were close relatives of wheat, in search of a BYDV resistant strain. They found several but had to come up with creative methods of breeding the resistance trait into commercial wheat lines.

By growing plant cells rapidly in an unorganised callus mass - a process that induces a high rate of chromosome exchange - researchers generated thousands of potentially resistant plants. From these plants five or six were shown to have the BYDV resistance trait and were bred into spring and winter wheats.

Mackellar is the first of the new resistant varieties to be available and has been commercialised by AWB Seeds under an exclusive licensing agreement. Early trials have shown a 26 per cent yield increase over most other commercially available wheats under standard field conditions. Named after the poet Dorothea Mackellar, the variety is being launched by AWB Seeds throughout 2003.

MACKELLAR FACTS

• Dual purpose winter wheat for grazing as well as grain production
• Very good level of resistance to stem, leaf and stripe rust
• Red feed quality grain
• Awnless (lacking bristles) to allow cutting for hay or late season grazing
• Excellent forage production
• The only BYDV resistant wheat cultivar in Australia

RAINFALL

Mackellar is best adapted to the high rainfall zones of Australia. This area includes the slopes of NSW, irrigated areas, the drier parts of the long growing season area in VIC, Tasmania and SA, and the cooler regions of southwest Wesrn Australia.

SOIL TYPE

Mackellar generally performs well on a range of soil types, however deep, well-drained soils are considered ideal. Winter wheats are able to tolerate waterlogging for short periods, although with reduced production rates. Mackellar is moderately intolerant of acid soils.

MATURITY

Mackellar is a long season variety which has a vernalisation (exposure to cold) requirement before it will flower and produce grain. When the vernalisation requirement has been met, flowering in Mackellar will occur at a similar time as Dennis or Declic. Mackellar can be sown from late February to June. If sown early, Mackellar must be grazed otherwise grain yield could be reduced. Mackellar has been selected to recover after grazing and produce high grain yields. Mackellar can also be grown as a grain only crop if sown from late March to late June.

PLANT CHARACTERISTICS

Mackellar is a red grained, feed wheat. It is awnless which makes it suitable for late grazing and cutting for hay. It has a medium harvest height, is moderately resistant to lodging and has been selected to recover after grazing to produce high yields. Similar to the other red-grained winter wheats Tennant and Rudd, Mackellar is tolerant to pre-harvest sprouting. CSIRO test results have shown Mackellar to have an average coleoptile length.

GRAIN CHARACTERISTICS

Mackellar produces grain that is red in colour and is classed as Australian Winter Wheat (AWW). Where separate winter wheat segregations are not available, winter wheat will be received as feed and binned with downgraded milling wheat varieties. Mackellar lacks certain baking qualities, which disqualify it as a milling wheat variety.

DISEASE AND PEST RESISTANCE

Mackellar has a very good level of resistance to stem, leaf and stripe rust.

PLANT BREEDERS RIGHTS

Mackellar is protected by Plant Breeder's Rights. Any unauthorised commercial propagation or any sale, conditioning, export, import or stocking of propagating material of this variety is an infringement under the Plant Breeder's Rights Act 1994. Growers are allowed to retain seed from production of this variety for their own use as seed only. A breeder royalty will apply to this variety, at a rate to be confirmed.

ACKNOWLEDGMENTS

Mackellar was bred by CSIRO with support from AWB Limited and growers through the GRDC. Yield testing and disease resistance assessment was carried out by CSIRO with support from various state departments and grower organisations.

More information on Mackellar at the AWB Seeds website.