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Britain risks losing its considerable lead in the plant breeding technology of the future unless it increases its spending, according to plant geneticists. And next week they will be putting pressure on the Centre for Exploitation of Science and Technology to back a plan to more than treble Britain’s efforts to map the genome of wheat.

Mike Gale, head of the Cambridge Laboratory of the John Innes Centre, which has its headquarters in Norwich, says: ‘Britain has the lead in this technology applied to wheat, but we are now under severe pressure.’ Japan and the US are investing heavily in crop genome research.

Gale and his colleagues were the first to develop restriction fragment length polymorphisms for analysing the genomes of cereal crops, and have built on that expertise to construct detailed genetic maps of barley, rye and pearl millet, as well as wheat.

The wheat genome is difficult to map for two reasons. It is huge, many times the size of the human genome, and hexaploid, containing six copies each of seven chromosomes. Each of those 42 chromosomes is equivalent to a third of the whole human genome. Undaunted, Graham Moore at the John Innes Centre began surveying the wheat genome.

Standard mapping procedures depend on homing in on informative coding regions in genes and ‘walking’ along the chromosome, past any uninformative repetitive DNA, to the next gene. Unfortunately, Moore’s group established that coding regions in wheat are few and far between, dispersed among blocks of simple, repeated sequences that make up more than 90 per cent of the genome. The huge repeats in wheat made standard mapping almost impossible, so Moore turned to rice.

Rice has a very small genome, with 12 chromosomes, less than half made up of repeats. Working with the Japanese National Institute of Agricultural Research’s Rice Genome Programme in Tsukuba, Moore looked for genes shared between rice and wheat, and discovered that although wheat and rice diverged some 60 million years ago, the order of the genes in the two species is essentially the same, even though the genes are much farther apart in wheat. Six of wheat’s chromosomes are identical to six of rice’s, while the seventh wheat chromosome is split in two in rice. The remaining four rice chromosomes are duplicates or end bits of the wheat chromosomes. ‘Essentially,’ says Moore, ‘rice is wheat without the repeats.’

The significance of this can barely be overstated. Moore and his colleagues say that they can reconstruct the ancestral cereal genome of 60 million years ago, and with it have shown that the genes of all the agriculturally important cereals – not just rice and wheat but sorghum, maize, rye, oats, barley and the rest – can be placed on a single map.

Moore has used landmarks on the rice genome to help wheat researchers like himself to home in on particular genes they are interested in, an approach that can be extended to the other cereals, too. And the shared map implies that genes for important characteristics, such as disease resistance, photoperiodism, drought tolerance, storage proteins and the like, can be plucked direct from one genome and applied in another.

‘The big prizes – and there are going to be some very big prizes – are going to come from transferring genes and knowledge between species,’ says Gale. The work is now going beyond mapping. ‘That is fun,’ Gale adds, ‘but it is only a stepping stone to fusing the biochemistry and the genetics across species.’

The rewards, he says, will be not so much higher yields as more sustainable yields, already being explored in relation to disease resistance. ‘Is rust resistance in wheat the same as rice blast resistance? Can we think of a kind of generic disease resistance?’

The shared genome map cries out for shared research, but the competitive advantage to plant breeders has apparently ruled out cooperation within the European Union. Europe has instead focused on the commercially unimportant thale cress, Arabidopsis, mainly because it has a very simple genome. The Japanese have adopted rice enthusiastically, and says Moore, just back from a new purpose-built rice genome institute in Japan, ‘have ten thousand rice genes sequenced, about half the genome’.

The main effort in the US has been in maize, but that is proving more difficult than barley, which is gaining increasing attention. The Germans, too, have proposed a large programme to map barley. That leaves the British to capitalise on their investment and expertise in their major crop, wheat.

Jerry Miksche, director of the US Department of Agriculture’s Plant Genome Research Program, says that more British effort on wheat would be ‘good logic, in that Great Britain’s research on wheat has made great strides’. The USDA is negotiating a deal between the US and Britain on sharing data, whereby wheat information would be deposited in the National Agricultural Library’s plant genome database in Maryland, and British scientists would receive software tools for interrogating the database.

Gale admits that the work in Britain has been reasonably well supported by the Department of Trade and Industry, the Biotechnology Directorate of the Science and Engineering Research Council, the Agricultural and Food Research Council, and by industry. ‘We have about £300 000 a year,’ he said, ‘which funds five or six posts. That’s terribly small beer compared to what’s going on in the US and Japan.’

The Japanese are spending £3.5 million a year on their rice genome programme, while the German barley proposal is for Pounds sterling 2.5 million. Miksche estimates that American efforts on all small-grain genome research receive about $240 million (about £165 million) a year.

‘An investment of only £1 million a year could accommodate the expertise that is already in place and generate more interest in other labs,’ says Gale. He hopes the new Biotechnology and Biological Sciences Research Council, which comes into being on 1 April, will agree.