Interaction of Rootstock and Soil Microbiome on the Performance of Vitis vinifera L cv. Pinot Noir at Mornington Peninsula Wine Region, Australia
Pangzhen Zhang
The infestation of phylloxera and climate change are two major challenges faced by the wine industry. Rootstocks are commonly used in viticulture to manage plant pests and diseases, as well as to mitigate abiotic stress and enhance grape and wine production. Despite emerging research evaluating the effects of rootstocks on grapevine physiology and wine quality, the majority of studies have focused on popular grape varieties such as Shiraz and Cabernet Sauvignon in warmer climate growing regions. The influence of rootstocks on Pinot Noir in cool climate regions has been rarely studied. To better understand the impact of rootstock on the performance of Pinot Noir, a rootstock trial was set up between 2014-2016 at two vineyards in the Mornington Peninsula wine region, Australia. At each site, the scions of V. vinifera L. cv Pinot Noir MV6 were grafted onto 14 rootstocks with ungrafted Pinot Noir MV6 planted as the control group. A series of evaluations were performed between 2018 and 2024, to understand the impacts of rootstocks on grapevine physiological performance, nutrient status, berry and wine composition, and the rhizosphere microbiome of grafted Pinot Noir. This study first compared the different impacts of rootstocks on grapevine phenology progress, canopy development, nutrient status, and endogenous hormones. To better understand the rationale behind such variations in scion phenotypes, this study further looked into the interaction between grapevine and soil. Results revealed the interaction between root exudates of grafted rootstocks and the rhizosphere microbiome, providing an innovative theoretical foundation for the mechanism of rootstocks in altering grapevine physiology. The study further assessed the quality of grapes and wine using analytical techniques and sensory evaluation. Among the studied rootstocks, Pinot Noir grafted to Merbein 5512 exhibited reduced vigor, but significantly higher anthocyanin content, fruit aroma intensity and overall sensory score. This research program contributes to the understanding of soil microbiome-rootstock-scion interactions, providing guidance to rootstock selection for cool climate Pinot Noir.
Acknowledgements
This study was initially set up by the Mornington Peninsula Vignerons Association (MPVA) in collaboration with Australia Wine Research Institute (AWRI), Yalumba Nursery, Commonwealth Scientific and Industrial Research Organisation (CSIRO). The scientific evaluation was performed at the University of Melbourne, supported by Melbourne TrACEES Platform and Mass Spectrometry and Proteomics Facility at the Bio21 Institute. The research was funded by Wine Australia, Wine Victoria and the University of Melbourne.
Pangzhen Zhang is a Senior Lecturer at the University of Melbourne. He is a viticulturist and food chemist. His key research interest is to study plant secondary metabolites that contribute to the sensory attributes of food and wine. Dr Zhang studies microbial terroir in Australia, which reflects the diversity of microorganisms in different vineyards across grapevine growing regions. His study demonstrated that vineyard microorganisms could regulate grapevine physiology through interaction with the root system, eventually finding their way to the fermentation tank and influencing the winemaking process. Dr Zhang investigates the impacts of different rootstock systems on grapevine physiology, their interaction with rhizosphere microorganisms, and ultimately the sensory quality and consumer acceptance of the resulting wine. Dr Zhang has authored over 100 peer-review publications with H-index of 38. https://findanexpert.unimelb.edu.au/profile/534594-pangzhen-zhang