Sweet hybrid grows 60 per cent more tomatoes

The tomato research could by applied to other crops such as corn and rice. Photo / Getty Images

A hybrid tomato plant that gives a bumper crop of sweeter tomatoes has been created by scientists, by cross-breeding from two parent plants.

The hybrid produces about 60 per cent more tomatoes than the average tomato plant, and the sugar content of the fruit is also higher than normal, the scientists said. It carries a mutation in a single gene that controls the timing of flower formation.

The discovery could be applied to other valuable food crops such as potatoes, peppers and aubergines, the geneticists hope. The crop-boosting mutation is seen as a potentially valuable tool to increase global food production in the coming decades, according to the research published in the journal Nature Genetics.

The scientists discovered the critical role of the florigen gene, which promotes flowering, by crossbreeding a collection of 5000 tomato plants that had been deliberately mutated, each in a different gene.

The researchers found that plants carrying one normal and one mutated florigen gene showed remarkable "hybrid vigour", with a significant boost in yield and sweetness.

Zach Lippman, of the Cold Spring Harbour Laboratory in New York, who was one of the research team, said the hybrid had the right balance of florigen protein to account for the extraordinary 60 per cent boost in tomato production.

"It's the Goldilocks concept. What we find is that to maximise yield, you can't have too much or too little florigen. A mutation in one copy of the gene results in the exact dose of florigen required to cause heterosis [hybrid vigour]," Dr Lippman said.

"Mutant crops are usually thrown away because of the notion that mutations would have negative effects on growth. Our results indicate that breeding with hybrid mutations could prove to be a powerful new way to increase yields, not only in tomato, but all crops," Dr Lippman added.

"It is possible that farmers could achieve the same high yields as commercial hybrids by using this one gene, and would be able to grow fewer plants.

"Alternatively, farmers could achieve even greater yields than is currently possible, and have higher sugar content - which is a second major component of tomato yield.

"We are hoping to test the concept of 'mutant hybrids' in other crops to see if yield can be manipulated in a similar way as we have shown in tomatoes. Crops that come to mind are corn, rice, and soybean, among others," he said.

"It's hard to say now whether our discovery will impact on food production and food security, but I think the point to be made is that there is untapped raw genetic material that could be exploited to achieve higher yields, not only in tomatoes, but in other crops."

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