A systematic and smarter approach to breeding and developing grapevine rootstocks adapted to Australian conditions

Abstract

Problems associated with adoption of high vigour rootstocks by the wine industry include negative impacts on berry composition associated with high potassium uptake, high grape juice pH, poor organic acid composition and reduced colour of wine. This project aimed to develop new rootstocks for winegrape production to minimise these problems. A further aim was to develop a smarter, focussed approach to the breeding and selection of rootstocks based on knowledge of the inheritance of key characteristics. Key outputs from the project included phenotyping of ungrafted populations of rootstock hybrids for rooting ability, grafting ability, nematode tolerance, mineral element (particularly K+) discrimination, transpiration efficiency, drought tolerance and root architecture; identification of 20 rootstock genotypes for further evaluation as grafted vines; identification of 4 new, low-medium vigour rootstock genotypes for commercial release with PBR protection; and preliminary analyses of genotype x environment interactions using existing data sets.

Summary

Knowledge on the inheritance of essential rootstock characterstics such as vigour, rooting and grafting compatibility, mineral discrimination and drought tolerance has been enhanced from analysis of data collected from rootstock progeny. New rootstock hybrids identified for further evaluation and established in the field after grafting with key scion varieties . Four low to moderate vigour rootstocks were released through licensed nurseries for larger scale commercial evaluation with PBR protection.