Tomato Taste Programmes – naturally altering the Fructose/Glucose ratio and the balance between sweetness and acidity- were being developed as far back as 1986. In Israel, a Volcani Center research group, led by Dr. Ari Schaffer and Dr. Moshe Bar (later with Zeraim Gedera/Syngenta) worked with the goal of developing tomato varieties with improved taste, reminiscent of the ‘tomatoes of old”. The strategy adopted was to utilize wild species of tomato to modify and improve sugar metabolism and accumulation in the commercial tomato fruit. Today, together with the Breedx tomato breeder, Noa Rona, the same researchers (Schaffer and Bar) have reunited in the framework of Breedx, a Company established in 2017. In the meantime, Breedx has introduced Intermediate Resistance (IR) to ToBRFV for the most advanced varieties in its breeding programme and will continue to work in this direction.
All cultivated tomatoes contain approximately equal amounts of the two hexoses, Glucose and Fructose, while the disaccharide Sucrose is absent. During the research program, the trait of Sucrose accumulation was successfully transferred by classical breeding techniques, molecular markers for the trait were developed and the breeding group was able to create novel varieties of Sucrose-accumulating tomatoes. A further strategy adopted was to modulate the Fructose and Glucose levels in the tomato fruit, considering that Fructose is twice as sweet as Glucose. At least two genes have been identified which act in consort to increase the ratio of Fructose to Glucose in the ripe fruit and germplasm with 3-4 fold Fructose has been developed. The Breeding Group is able to increase soluble sugars and to control Sucrose, Glucose and Fructose levels and control the sugar/acid ration by the use of Molecular Markers linked directly to specific traits.
Varieties being developed in this programme – in three different segments of shape (tear drop, peanut shell and egg plum) with no globe or round fruit – are mostly aimed at single pick, fruit size between 8 – 25 grams with brix of no less than 9.0. There are two basic fruit colours – chocolate/brown and shiny red – some varieties with highly-attractive mottling and striping. These varieties are being trialed today worldwide, in Europe, in North America, in Japan and in South Africa.
This intensive tomato activity at Breedx is in parallel with continuous development of the seedless sweet pepper segments – three colours, from small one-bite fruits to mini-capia.