Advanced grapevine genetics for varietal improvement

Abstract

This project was successful in using advanced genetic approaches for both strategic and applied grapevine research. The methods developed resulted in the creation of a mutagenized grapevine population for gene function studies and the discovery and linking of DNA markers to key agronomic and berry traits. Crucial to the success of the project was the use of microvine material that flowered quickly and had a short generation time. The DNA markers were further developed and used to determine if marker-assisted selection (MAS) was possible for speeding up the process of producing new grapevine varieties. Over 8,000 young grapevine seedlings in a glasshouse were screened with DNA markers for mildew resistance, flower sex and berry colour and over 1,200 that passed the DNA screen were planted in the field for evaluation. The DNA markers accurately predicted the phenotype of the plants in the field. This first generation of powdery and downy mildew resistant selections displayed no evidence of mildew in the field in a no-spray vineyard. To identify elite selections within the 1,200 vines, assessment of agronomic performance and berry and wine attributes was initiated with both white and red selections found to have variation in yield and diverse wine flavours.

Summary

The future competitiveness of the Australian wine industry will depend on reduced input costs, sustainable production methods and a differentiated product that appeals to different markets and changing consumer preferences. Genetic solutions, in the form of new varieties, have been key to overcoming disease problems, increasing yield and producing new products in many crops. Improved grapevine planting material that reduce costs, produce new or improved wine styles and are better adapted to the changing Australian climate will provide industry with new options for maintaining profitability. However the main scientific barriers to producing new winegrape varieties have been the lack of genetic knowledge on what genes control key traits and the long generation time of the grapevine plant making breeding slow and difficult.