Researchers have developed a genetically engineered dandelion that produces more latex that could be used in gloves, tyres and drugs.

If you pop the head off a dandelion, white sap oozes freely from the wound for about a second.

But if you pop the head off the genetically engineered variety, the sap oozes for minutes, producing five times more latex than from the average dandelion.

"We have identified the enzyme responsible for the rapid polymerisation and have switched it off," says Dr Dirk Prufer, a scientist at Fraunhofer Institute in Munich, Germany, who is developing the technology.

"If the plants were to be cultivated on a large scale, every hectare would produce 500 to 1000 kilograms of latex per growing season."

For thousands of years, most of the world's rubber has come from tropical rubber trees. A diagonal cut in the trunk allows the white latex to drip into hanging cans, which can then be harvested and eventually turned into a variety of materials.

But natural rubber contains trace amounts of biological impurities. For car tyre makers, those impurities give vulcanised rubber a give and elasticity they can't get anywhere else. For some hospital workers, however, those same impurities can trigger life-threatening allergic reactions.

Synthetic or petroleum-based rubber typically has fewer impurities than natural rubber which makes it ideal for applications like allergy-free gloves