A study led by researchers of the Spanish National Research Council (CSIC) on Hydra tomatoes has identified a key gene in the production of seedless tomato fruits. The results of the research have been published in the journal New Phytologist.

Hydra tomatoes are 40% smaller and weigh 80% less than the classic variety (Solanum lycopersicum) from which the mutation has been obtained. According to the researchers, this could be because the seeds are sources of hormonal signals that promote the growth of the ovary in wild plants.

The researcher, Concha Gómez Mena, from the Institute of Molecular and Cellular Biology of Plants, a mixed centre of the CSIC and the Universitat Politècnica de València (UPV), has highlighted that "parthenocarpic or seedless fruits are interesting in agriculture, as they allow the growth of the fruits ovary without the need for fertilization; an advantage in case the environmental conditions are not ideal for pollination."

For consumers, their value lies in the fact that "the absence of seeds can increase the fruits shelf life, and it is also advantageous for the manufacture of tomato juices and pastes," for which seeds have to be removed during the processing.

Gene cloning and silencing
Using cloning techniques, gene silencing and expression analysis experiments, CSIC researchers have identified the Hydra gene, which is similar to the Sporocyteless/Nozzle gene of the Arabidopsis model plant. The study carried out in the tomato has revealed a new function for these genes: the prevention of the early growth of the ovaries, and since the gene is inactive in the Hydra variety, the fruits developing have no seeds, as explained by researcher José Pío Beltrán, of the Institute of Molecular and Cellular Biology of Plants.