Genetic Modification Increases Tomato Plant Yields

COLD SPRING HARBOR, N.Y.One genetic mechanism in production tomato plants can be modified to increase length of time that bushy tomato varieties can produce flowers, thus increasing yields, according to a new study published in the journal PLOS GENETICS.

Tomatoes that will be canned for sauces and juice are harvested from plants that stop growing earlier than classic tomato varieties, and are therefore more like bushes. While the architecture of these compact bushy plants allows mechanical harvesters to reap the crop, the early end of growth means that each plant produces fewer fruits than their home garden cousins.

Cold Spring Harbor Laboratory (CSHL) researchers revealed one genetic mechanism for hybrid vigoror heterosis, as biologists call itthat can be modified in the production tomato bushes to increase crop yields. Hybrid vigor involves interbreeding genetically distinct plants to generate offspring more robust than either inbred parent.

By teasing out the hidden subtleties of a type of hybrid vigor involving just one gene in the tomato plants, researchers were able to tweak the length of time that bushy tomato varieties can produce flowers. In these plants, longer flowering time substantially raises fruit yield.

In a prior study, researchers identified a rare example of hybrid vigor involving a genetic defect in the gene that makes florigen, a hormone that controls the process of flowering and flower production. The mutation dramatically increases tomato yields in bush tomatoes.

"This is because bushy tomato varieties are highly sensitive to the amount, or dosage, of the florigen hormone, which alters plant architecturethat is, how many flowers can form before growth ends," said CSHL Associate Professor Zach Lippman. "These discoveries lead to an exciting prediction: that it may be possible to tweak florigen levels to increase yields even further."

Earlier this year, USDA Agriculture Research Service (ARS) scientists identified a way for breeders to develop tastier, garden-fresh tomatoes that consumers crave.