Wageningen University & Research partners with companies to map massive onion genome

In January Wageningen scientists are presenting the first version of the genome of the onion. Breeding a new onion variety normally takes around 16 years but insights into the DNA sequence will make things much easier from now on.

The onion is one of the most commonly used crops worldwide and - after the tomato - the second largest vegetable crop in terms of production value. But where the genetics of the tomato have already been thoroughly mapped, the onion was largely unknown until recently. This is partly due to the size of the genome: the genome of the onion is five times larger than the human genome, and 18 times larger than the tomato genome. 

Production and trade of onions

Knowledge of onion genes is very important to Dutch breeders of seed onions. The Netherlands is one of the largest producers of seed onions and 90 per cent of Dutch production is exported. But an onion that is successful in the Netherlands may not do so well in other countries. Some onions only produce bulbs when the days are long, for instance in Northern European summers, not when days are short, as is common nearer the equator. There is already a lot of knowledge into the influence of day length on the model plant Arabidopsis and scientists hope they can apply this knowledge to onions once the sequence of the genome has been mapped.

Genome for global food security

Wageningen University & Research is mapping the genome in partnership with two companies - breeding company Bejo Zaden and Service XS. Breeding companies currently need some 16 years to develop a new onion. The new knowledge is likely to halve that to eight years. As well as being good news for fans of onion dishes, it is also very important to global food security. Onions are a major part of the diet in many countries, and an excellent source of vitamins, minerals and dietary fibres. A greater insight into the genetics of the onion will create the opportunity to breed onion varieties that grow better on infertile soils, improving food security. “I expect the onion breeding process to be twice as fast as a result of this project, ” says Henk Huits, Manager Marker technology & Genomics at Bejo.