TABLE GRAPE BREEDING AT THE ARC INFRUITEC-NIETVOORBIJ, SOUTH AFRICA; ITS IMPACT ON THE SA INDUSTRY AND LATEST DEVELOPMENTS

Abstract

Since its inception in 1952 and first releases in 1965, the ARC table grape breeding program released a total of 28 cultivars. In 1985 one ARC cultivar (?Bien Donne?) made a noteworthy contribution to export (3%), while the contribution of six ARC cultivars was 25,9% of the total export in 2006. Changes in consumer preferences necessitate regular revision of aims. For example, export of seedless cultivars from SA grew from a minimal contribution in 1985 to over 52% in 2006 and is still growing. New seedless cultivars are developed by in vitro embryo rescue techniques, while crosses to develop seeded cultivars with unique characteristics are also made. The first seedless cultivar was released in 1986, followed by another five seedless cultivars. Two new, early ripening, red seedless cultivars will be released in the near future to the SA industry. Since 2004, DNA technologies and molecular approaches were introduced as an essential component of the disease resistance breeding program. An extensive DNA fingerprint of table grape cultivars/selections was constructed and is used to solve identity issues. ?Regent?, an interspecies hybrid, is resistant to powdery and downy mildew (Fisher et al., 2004) and was used to introduce resistance into the ARC table grape breeding program. We report validation of the resistance loci previously identified, following a QTL approach in a ?Regent? × ?RedGlobe? population. We identified plants that phenotypically displayed resistance to both downy and powdery mildew, whilst also carrying flanking markers for both resistance QTL. These plants are prime candidates to be used in future crosses to introduce resistance, whilst also selecting for good fruit quality. The population and the genetic map is a valuable resource that can be used in future to map other disease resistance loci present in Regent or fruit quality traits of ?RedGlobe?.