Biotechnology for BYD virus resistance in wheat

• Chinese Academy of Agricultural Sciences, China

This project has developed from a previous ACIAR project entitled 'Plant Biotechnology for Wheat Germplasm Improvement' (Project 8379). In the course of the project investigations into the disease caused by Barley Yellow Dwarf (BYD) Virus came to dominate the project, because of its significance as a disease of cereals worldwide and the excellent potential for utilising the sources of disease resistance that were discovered.

The major objective of this project is to introduce sources of resistance to BYD virus presently found in wild grasses into lines of wheat using genetic engineering techniques. In the earlier project 27 accessions of grasses in the family Triticacae were screened for resistance to BYD virus, and 13 showed some level of resistance. The most promising are now being studied in greater detail.

Other components of research in this project are: continued screening for more sources of resistance, concentrating on the grasses Triticum tauschii, Aegilops sp., and Agropyrum sp.; to use an array of techniques of genetic engineering to introduce BYD virus resistance from the grass Thynopyrum intermedium into wheat, and to refine the tests for tracking the fate of the introduced genetic material; to define the impact of the disease in China and Australia, and the relative importance of the new sources of resistance in comparison to the most disease-tolerant lines presently available in wheat; to complete the gene sequencing for the virulent Chinese isolate, GPV, and to compare the sequence with other isolates in order to clarify virulence at the molecular level; to catalogue the differences between the resistance genes in terms of their reactions to the various virus isolates, important data for determining the most significant genes to include in the study; to investigate the ecology of BYD virus in aphids and plants in China, using the ELISA test and DNA probes.

Researchers are confident that the project will result in BYD-resistant lines of wheat which will be a major breakthrough for wheatgrowers, both in the developing world and in Australia. In the course of the conducting the project there will be a transfer of technology to scientists at the Chinese Academy of Agricultural Sciences, building up their research capacities in areas such as cytogenetics, ELISA assays, DNA marker usage, cell culture methods, ph-mutant utilisation, and virus genome cloning and analysis.