Genetic diversity of Australian wine grapevine germplasm
Summary
Objective
This project will deliver a foundational database that is fit for purpose to robustly identify the majority of grapevine varieties and clones of economic importance within Australia. The number of grapevine cultivars and clones sequenced in previous work will be expanded upon so that, by the conclusion of the project, the total dataset will consist of at least 800 genome sequences from Shiraz, Chardonnay, Riesling, Pinot and Cabernet Sauvignon. A further two varieties will be determined through consultation with the already- established Industry Reference Group (IRG), which comprises collection owners and key propagation industry representatives.
In its final year, the project will apply the sequencing methodology to uniquely Australian heritage grapevine germplasm, focusing on ancestor vineyards (pre-1900). This will provide historical insights regarding the origins of these plantings and how heritage material relates to currently available commercial germplasm.
Background
Grapevine planting material represents a major investment and critical production asset for the Australian wine industry, but the genetic diversity that is present in Australia is poorly understood. Furthermore, while grapevine cultivars can be unequivocally typed by ampelography and/or genetic tests, clonal identification currently relies on the tracing of supply records to the point of origin. Such records are not always available or reliable, particularly for older accessions.
The AWRI has developed a world-first sequencing methodology that combines the latest next-generation genome sequencing technologies, high-performance computing and customised bioinformatics tools to define grapevine cultivars and more importantly, clones of those cultivars. The technique has been used to define a subset of clonal variation in Chardonnay (AWR 1701-4.3.1: Characterising genomic diversity in Australia’s grapevine germplasm), and to investigate sequenced-verified sources of specific Pinot Noir clones for bushfire recovery efforts (AWR 2001: Clonal mapping of Pinot Noir). In addition, the method was used in the first phase of this project to sequence around 380 clonal samples of Shiraz, Chardonnay, Pinot Noir, Cabernet Sauvignon and Riesling, from which phylogenies were constructed and clonal genetic variation determined (AWR 1701-4.4.5: Sequencing Australian wine grapevine germplasm).
A pivotal era for Australian winemaking and viticulture occurred around the 1830s and 1840s, when a number of pioneers began importing large assortments of grapevine cuttings from Europe. Importantly, these early vines arrived in Australia before phylloxera devastated the European viticultural industry, and many of these historical Australian vineyards survive to this day. Because of this, in spite of the relative youth of Australian viticulture, the country possesses many of the oldest plantings of Shiraz, Grenache, Semillon and Pinot (plus several other varieties) in the world. These unique vines and the grapes they produce have played an important role in Australia’s grape and wine community. They are behind some of the country’s most extraordinary wines and have helped shape some of Australia’s classic wine styles; however, their connections to their contemporary clonal counterparts remain largely unknown.
Sector benefits
The database will provide a platform that could underpin provision of cultivar and clone identification as a commercial service for the sector. Applications include DNA-based certification of germplasm in nursery and/or vine improvement settings, determination of unknown vineyard plantings and provision of genetic information on heritage grapevines. The Australian wine sector's demand and requirements for such a service will be tested separately through a co-innovation process in project AWR 2202-3.3.7: Grapevine Clonal ID.
Results from the heritage germplasm work will underpin Wine Australia’s ‘Australian Wine Discovered’ education program on Old Vines, may lead to additional testing targets for inclusion in a genetic test of clonal identity, and will identify heritage clones and vineyards for enhanced preservation efforts under the National Grapevine Collection program and/or clonal propagation by nurseries.