A RESEARCH proposal now being considered by the Grains Research and Development Corporation (GRDC) could speed the incorporation of black point resistance in new wheat varieties. The disease, which costs the country an estimated $52 million a year in lost production, is particularly prevalent in northern and western regions. The research, proposed by the University of Southern Queensland (USQ) in Toowoomba, could see molecular markers for black point resistance identified by December 2001. The markers should be fully validated and available to Australian wheat breeding programs a year or two later. While it could take up to 15 years to eliminate black point susceptibility from varieties, Australian graingrowers could expect to see the first improved varieties with resistance to the disease within three or four years. Plant breeders will be able to set minimum standards of black point resistance for future wheat releases. And there could be spin-off benefits from the research because some of the wheat genetic material likely to be studied also segregates for a number of other important traits, including resistances to yellow spot and preharvest sprouting. That could lead to the development of molecular markers for those resistances, too. If approved, the $250,000 investment will be the newest in a suite of research projects targeting black point to be supported by the nation¹s graingrowers and the Federal Government through the GRDC in recent years. The proposed research would bring together an impressive biotechnological team, to be led by Grant Daggard, a plant molecular biologist at USQ also working on a GRDC research into genetically engineering frost tolerance into wheat. Other team members would be USQ plant pathologist and biochemist, Associate Professor Mark Sutherland; Queensland Department of Primary Industries senior plant pathologist Dr Peter Williamson, internationally recognised for his research into the basic biology of black point and the development of improved techniques for rapid screening of black point resistance; and Dr Anna Campbell, a specialist in the areas of plant genetics and breeding and also involved in research at USQ within the GRDC¹s National Wheat Molecular Marker Program. "Symptoms of darkened grain, usually at the brush end, have often been associated with the presence of the fungus Alternaria alternata, in the grain," Dr Daggard said. "But recent research by Dr Williamson has shown that discolouration of the grain at the embryo end is associated with peroxidase enzymes rather than fungal hyphae. "The physiological role of these peroxidase enzymes ‹ and assessment of their role as markers for screening for black point ‹ is being evaluated in other streams of GRDC research, but it¹s been found that the presence and amount of peroxidase enzymes in resistant and susceptible varieties are influenced by the environment. "That reduces their value as a screening tool. "This project aims to develop markers for black point ‹ which will allow screening for black point regardless of environmental conditions. "That would enable direct selection for black point resistance/susceptibility within Australian breeding programs." Dr Daggard said a second aim of the project would be to obtain information about the actual genes involved in the symptoms of black point, rather than relying on molecular markers associated with those genes. This was a natural extension of developing a DNA-based marker system in that it would allow a better understanding of the causes of the disease and enable breeders to access molecular tags linked directly to gene expression for long-term control of black point symptoms. "The research will be relevant to all Australia¹s wheatgrowing areas, but in particular the northern and western regions, where black point is a more consistent problem," Dr Daggard said. "In 1995-96, the Australian Bureau of Agricultural and Resource Economics (ABARE) estimated annual losses from downgrading because of black point to be $52.28 million nationally. "The improved knowledge of black point gained from this project will also benefit the barley industry."