South Africa Wine Research Projects 2025

2. VITICULTURE RESEARCH COMPLETED PROJECT

SCREENING FOR POTENTIALLY NOVEL PINOTAGE CLONES GENERATED THROUGH IRRADIANCE MUTAGENESIS P04000060-2019 Ms Phyllis Burger, ARC Infruitec-Nietvoorbij, Stellenbosch and Prof Melané Vivier, South African Grape and Wine Research Institute, Stellenbosch University Project is co-funded by ARC Infruitec-Nietvoorbij Project completed: 2023 AIM AND INDUSTRY RELEVANCE: Pinotage is a uniquely South African grape variety with limited clonal diversity due to its relatively recent development and limited cultivation history. As the demand for Pinotage wines grows locally and internationally, the availability of improved clones with varied attributes, such as looser bunches, altered berry colour, or earlier ripening, is essential to enhance vineyard performance, fruit quality, and wine differentiation. This project aimed to increase clonal diversity in the Pinotage grapevine cultivar by inducing novel genetic mutations through gamma irradiation. Detailed phenotypic screening of more than 1,400 treated and control plants was conducted to identify unique individuals with desirable traits, to select potential improved Pinotage clones for future propagation and commercial release. The study demonstrated that gamma irradiation can induce significant phenotypic variation in Pinotage grapevines, offering a promising strategy to expand clonal diversity. From over 1,400 treated and control plants, 500 were selected for a field trial, where irradiated vines showed increased variability in leaf shape, growth habit, and fruit characteristics compared to controls. During the first fruiting season, 34% of the vines produced grapes, with several irradiated plants displaying desirable traits such as looser cluster architecture, unique berry skin and flesh pigmentation, and altered growth patterns. These outcomes confirm the effectiveness of induced mutation for generating novel traits, providing a valuable foundation for the identification and future selection of superior Pinotage clones suited to diverse viticultural and market needs.

SOUTH AFRICA WINE RESEARCH 2025

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