Wheat genome work applauded – but much work remains


A major scientific breakthrough that could lead to new wheat varieties with drought tolerance, resistance to diseases and higher yields.



That’s how the global media reported the recent announcement that a team of UK researchers had published the first sequence of the wheat genome.


It generated sensational headlines such as “the most significant breakthrough in wheat production in 10,000 years” and “a scientific tour de force”.


However, the International Wheat Genome Sequence Consortium stresses that there is much work still to be done, highlighting that the reporters failed to appreciate that the released sequence information is still in a raw form.


For plant breeders working on the next generation of wheat varieties, it’s a welcome development which has received an enthusiastic response across the board.


“It’s the first attempt at complete genome coverage, which is fantastic,” says Richard Summers, vice-chairman of the British Society of Plant Breeders and head of cereal breeding at RAGT Seeds. “It’s also been done in a collaborative manner, which is just what the plant breeding community wanted to see.


“It’s a really good example of how to get some very important, relevant science out to commercial outlets, so that it can be used in agriculture, for the benefit of all.”







WHEAT GENOME
• Genome sequence published in raw format
• Bread wheat variety Chinese Spring line 42
• Five times larger than human genome 


What it gives companies like RAGT Seeds is an insight into the ability to develop a new set of markers known as single nucleotide polymorphisms, or SNPs, which Dr Summers describes as the ultimate marker system.


“With SNPs, there’s the potential for us to have many tens of thousands of different markers,” he reveals. “In comparison, the current marker system we’re using, which is known as SSRs (simple sequence repeats), has only a few thousand.”


His colleague, Peter Jack, cereal genotyping manager, explains that SNPs offer the company two main technical advantages.


“They can be developed very near to the genes and they’re much easier to use in the laboratory. That means our throughput capacity can be increased.”


As a practical tool, SNP markers won’t be ready for another couple of years, he adds. “It’s revolutionary technology which will be extremely useful to us. But more investment is needed for the next step and the project still has time to run. Things are evolving very quickly.”


For growers, the inclusion of new markers in practical breeding programmes will bring genetic benefits in new wheat varieties. Yield, quality and disease resistance are likely to improve, as SNP markers will allow breeding to become both quicker and more targeted.


“These markers can be applied to younger generations and over bigger numbers,” continues Dr Jack. “They will allow us to move from phenotype to genotype, making the breeding process more controlled and removing some of the genetic bottlenecks that have been associated with wheat breeding in the past.”


Bill Angus, wheat breeder with Nickerson, part of Limagrain, is also positive about the latest developments and applauds the work of the UK team, describing it as a significant step forwards.


“The challenge now for the plant breeding community is to work out how to optimise its use. We are building information about the way that plants work at a very rapid rate – the progress made in the last three to four years is greater than that of the previous 20.”


He points out that the sequencing of the human genome hasn’t led to the development of designer drugs yet, so growers will have to be prepared to wait a bit longer for the next generation of wheat varieties.


“It’s another set of tools and a useful platform, rather than the silver bullet. It opens up opportunities for traits to be included which have a value to growers, such as drought tolerance and disease resistance.”


Mr Angus expects that, as a result of the latest development, varieties which come to the market in the next five to 10 years will be more resilient and robust, with better consistency levels. “It should get rid of the booms and busts, such as variety breakdowns to new races of rust, for example.”


 

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