conference schedule and program with abstracts - Horticulture ...

O-18
Table grape breeding at the ARC Infruitec-Nietvoorbij, South Africa: its impact on the
South African industry and latest developments
P. Burger* 1 , C.J. van Heerden 2 , A. Vermeulen 1 , F. Halleen 1 , T. Koopman 1 , R. Prins 3
1 ARC Infruitec-Nietvoorbij, Stellenbosch, South Africa; 2 Department of Genetics University of
Stellenbosch, Stellenbosch, South Africa; 3 CenGen (Pty) Ltd., Worcester, South Africa
*Corresponding author: burgerp@arc.agric.za
Since its inception in 1952 and first releases in 1965, the ARC table grape breeding programme
released a total of 28 cultivars. In 1985 one ARC cultivar (Bien Donné) 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 South Africa 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 near future to the
South African 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 against powdery and downy mildew (Fisher
et al 2004) and was used to introduce this resistance into the ARC table grape breeding program.
We report validation of the resistance loci previously identified, following a QTL approach in a
Regent x Red Globe 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.
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