By Shai Leviatov, Manager Tomato Breeding
& Golan Abend, Cherry Tomato Breeder
ShaiL@zeraim.co.i, Golan@zeraim.com

In recent years, the market position of Zeraim Gedera cherry tomato varieties has become well established, with significant market shares in both Israel and in Spain, and good results in other territories such as Morocco where this category of tomato has started to be grown.

As in “regular” tomatoes (if there is such thing) the cherry tomato market in recent years has undergone major changes in customer preferences resulting in a greater variety of product types in greenhouses and on store shelves. Zeraim Gedera’s cherry tomato breeding program has reflected these changes as could be seen this year in the breeding greenhouse with a wide range of experimental varieties of cherry-cluster, grape cherries and varieties with yellow and orange colored fruit.

Grape Cherry Tomato
With three major (consumer) markets in mind -United Kingdom, NAFTA (USA and Canada) and the Peoples’ Republic of China - Zeraim Gedera has embarked on a breeding program directed at so-called “grape tomatoes”. The term “Grape Tomatoes” refers in the main to fruit size and shape. The fruit size has to be small, somewhere between 20 - 25 mm., whereas the shape is slightly elongated, length 27 - 37 mm., called ‘plum-shaped’ by some, or ‘grape’ by others.
Within each parameter, there are a number of sub-parameters

• Fruit size - a range of sizes within the above-given dimensions.
• Fruit shape - plum, egg-shape, ampoule-like pear shape, etc.
• Target market - “one-bite”, salad fruit.

All varieties have the characteristics of high sweetness, less internal liquid and therefore a relatively high level of dry matter.
Experimental varieties have been selected for further larger-scale trials in different parts of the world.

• In Culiacan (Mexico) for outdoor production with high yield, good leaf coverage and acceptable fruit shape.
• In greenhouse trials in U.K. because of attractive fruit shape, high brix and good flavor.
• Plum, or grape, varieties- harvested in clusters, tested primarily for the Italian market.

For those who want to vary the color of their salads, we offer an orange plum cherry tomato.
Most of these varieties carry a wide range of disease-resistance genes. All are ToMV resistant; some are also resistant to Nematodes, and - especially for Mexico and Australia - most of the plum cherry varieties are resistant to Fusarium 3.

“On-the-vine”, cluster Cherry Tomato
Traditionally, Italy has been the major market for cluster cherry tomatoes. In recent years however, other markets such as Israel, NAFTA and Spain are showing interest in this high quality product. During the 2005 breeding season, several new varieties have been selected to support Rubino-Top in a segment where competition is increasing. All our new varieties are characterized by a vigorous plant with short internodes, well-arranged fruit clusters with uniform fruit-setting and extended calyx shelf life. All the varieties are resistant to V, ToMV and Fu2, and tolerant to Nematodes. Some are also resistant to FCRR and Cladosporium.

Introduction of resistance to Fus 3 TSWV and TYLCV
Breeding with the consumer in mind is only part of the story in breeding marketable new varieties; the occurrence of new diseases poses new threats for tomato growers in different territories. Such diseases are Fusarium Race 3 in Culiacan Mexico, in Australia and in South Africa; Tomato Spotted Wilt Virus (TSWV) in spring production in Italy, in Spain, in Baja California and in Turkey; and Tomato Yellow Leaf Curl Virus (TYLCV) in the Mediterranean countries and others. To achieve resistant/tolerant varieties to new diseases takes years of breeding work. The Fusarium-resistant new plum varieties are the result of earlier work by our cherry Breeders.
TYLCV is a devastating disease in Mediterranean countries and has limited tomato production including of Cherry tomatoes. Recognizing this fact, we have been working on developing TYLCV - tolerant Cherry lines and hybrids for more than three years. Some of these hybrids selected are being promoted in Spain (single) and Italy (cluster). The project is running “full steam ahead” with the goal to develop high tolerance to TYLCV in varieties that produce high yields of excellent quality tomatoes.
TSWV - resistant cherry lines have been developed in recent years and a new set of TSWV - resistant varieties has been produced. These varieties are on trial this season, spring 2005, in Baja California (Mexico).