Single gene powers hybrid tomato plants - study

A mutation in a single gene can turn hybrid tomato plants into super producers capable of generating more and much sweeter fruit without genetic engineering, scientists said in a study.

The study also showed that using classic plant-breeding techniques can boost yield as dramatically as using genetically modified organisms, said researcher Zachary Lippman of Cold Spring Harbour Laboratory in New York.

The mutation in one copy of the gene boosted tomato yield by up to 60 per cent and increased sugar content, Dr Lippman and colleagues reported in the journal Nature Genetics.

"When this gene is only working at half speed... there's this rebalance of growth that's happening that occurs across the entire plant that gives you this increase in yield," remarked Dr Lippman.

The yield-boosting power of the gene known as single flower truss, which controls when plants make flowers, worked in different varieties of tomatoes and in different environments, he said.

"No matter what soil type, no matter what sort of irrigation you give it, no matter what fertilisation you give it, you're always having some sort of effect," he said. "We try to keep it conservative and say 60 per cent. Sometimes it's a little lower, sometimes it's even higher."

When both copies of the gene are working, the result is a completely normal plant. "But when one copy is working, you see the heterosis. This is the magic of the discovery," remarked Dr Lippman.

Heterosis, or hybrid vigour, is the genetic mechanism that makes offspring of cross-bred plants more vigorous than their parents.

Dr Lippman said the finding could have significant impact on agriculture and the next step was to look at the effect in corn, soybeans and other crops.