Project title:
Analysing induced diversity in a collection of Pinotage plants after gamma irradiance
Project number:
P04000060-2024
Project leader:
Prof Melané Vivier
Institution:
South African Grape and Wine Research Institute, Stellenbosch University
Start date:
2024
Co-funder:
ARC-Infruitec-Nievoorbij
Project description:
Pinotage has only a few commercially available clones similar in viticultural and oenological properties. Under the leadership of Phyllis Burger (ARC Infruitec Nietvoorbij) and Prof Melané Vivier (SAGWRI), a project was initiated to attempt to enhance clonal diversity in Pinotage by accelerating mutations that typically lead to clonal diversity. The first phase of this multiphase project, conducted from 2017 to 2018, was dedicated to optimising the methodology to create mutations in three existing Pinotage clones. This established a gamma-irradiated Pinotage collection of approximately 1500 plants with potential mutations.
The second phase of the project lasted from 2019 to 2023. This phase involved characterising the collection of plants that originated from irradiation and comparing them to the three original Pinotage clones. A subset of the plants was chosen to establish in a field trial of 500 plants, including controls. The collection was successfully planted in 2021 and evaluated over two seasons already. The residual plants were also planted in the field in 2022 for further analysis. The results from this phase of the project were presented to the Pinotage Association, requesting their input in the selection of desired traits in clones going forward.
The third phase (this project) aims to build on the previous work and conduct viticultural and oenological analyses on chosen subsets of the vines to identify potential material for new clonal selection of Pinotage.
The objectives for this project are as follows:
- Develop a data management plan for the project.
- Maintain and extend the field site where an irradiated population of Pinotage plants are kept.
- Investigate the effects of gamma irradiance on the cluster, canopy, and wine quality traits of three Pinotage clones in a field trial site.
- Select promising individuals for grafting to rootstocks for further analyses.
More options regarding Pinotage clonal diversity are essential for the South African Wine industry since the cultivar has originated in South Africa and is widely planted. Although Pinotage already has fantastic attributes that need to be ‘kept’ in new clones, clonal material with a slightly different phenological progression, and specifically ripening progression, favourable wine pH, acid balance, as well as phenolic maturity (to name only a few), could provide valuable options to producers and winemakers in terms of Pinotage production and wine styles. The project’s outcomes would be new plant material, either in the form of novel Pinotage clones, potentially new cultivars (for example, a white Pinotage), or breeding lines with novel characteristics that can be used in the ongoing traditional breeding programme. All of these outputs will directly benefit the wine industry.
The South African Pinotage Association supports the project in principle and financially. In addition, they provide all the wines needed to compare the chemical and sensory descriptions of the current Pinotage clones against the new material. The project also supports several postgraduate students participating in the research as part of their research activities towards their degrees.