The Power of Three: Wheat Trigenomic Chromosome

Scientists from the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Sydney University, and the International Maize and Wheat Improvement Center (CIMMYT) have combined the resistance genes from three different grass species to develop the first ‘trigenomic’ chromosome. The trigenomic chromosome can now be used to breed disease-resistant wheat varieties.

Researchers have known that wild wheat relatives harbor a collection of valuable genes that may confer resistance to various diseases and pests. But transferring these genes, using conventional breeding approaches, remains troublesome. Most of the genes are linked together, so introducing a gene of interest also means introducing several undesirable genes. Furthermore, the linked genes tend to stay together even after many generations of breeding.

The researchers have successfully recombined two gene blocks from two different Thinopyrum species, a wild wheat relative. The recombined blocks carry resistance genes for leaf rust and Barley Yellow Dwarf Virus (BYDV), two of the world’s most damaging wheat disease. It may also harbor resistance genes against the new stem rust strain, which is currently on a worldwide march. The gene blocks contain no problematic chromosomes which may affect the wheat's agronomic properties. Scientists are now looking for ways to apply their discovery to other crops like corn, rice and soybean. 

Read the press release at http://www.csiro.au/news/DiseaseBeatingWheat.html

The abstract of the paper published by Theoretical and Applied Genetics is avaialable at http://www.springerlink.com/content/6g14315t27732627/?p=2c1cba2797f14ab7a5ea7c61ef0eb551&pi=6