Building disease-beating wheat
Pioneered by CSIRO researchers, in collaboration with the International Maize and Wheat Improvement Center (CIMMYT) and Sydney University, the research illustrates the major genetic improvements possible without genetic modification (GM) technology.
鈥淲heat breeders often use wild relatives of wheat as sources of novel genes in breeding new disease-resistant wheats,鈥� research team leader Dr Phil Larkin says.
鈥淯nfortunately genes from wild relatives usually come in large blocks of hundreds of genes, and often include undesirable genes. Furthermore, these blocks of genes tend to stay together, even after many generations of breeding.
鈥淭he problem can be so difficult to overcome that plant breeders sometimes give up on very valuable genes because they cannot separate them from the problematic genes.鈥�
A paper published this month in the respected international journal Theoretical and Applied Genetics details how the team 鈥榬ecombined鈥� two wild blocks of genes from two different Thinopyrum grass species 鈥� a wild relative of wheat 鈥� bringing together resistance genes for leaf rust and Barley Yellow Dwarf Virus (BYDV), two of the world鈥檚 most damaging wheat diseases. The recombined gene 鈥榩ackage鈥� may also carry a resistance gene against a new stem rust strain which is causing concern worldwide.
鈥淭he exciting part of the new research is that we have been able to retain the useful genes but leave behind the associated undesirable genes - most notably in this case those for yellow flour colour, an important quality characteristic in wheat,鈥� Dr Larkin says.
By developing new 鈥楧NA markers鈥� and by careful testing the team has produced a number of the disease resistance 鈥榩ackages鈥� for wheat breeders, making it faster and easier to include these important disease resistance traits in future wheat varieties.
Source: CSIRO Australia
