Abstract

Carbohydrate content and balance play an important role in determining the flavour and processing quality of the strawberry. As the fruit ripens, the sugar balance favours the hexoses glucose and fructose rather than sucrose. This will have consequences for the osmotic potential of the fruit cells and may result in an overall adjustment of water import, fruit growth and potential for processing. In many fruit species the enzyme invertase is responsible for catalysing the breakdown of sucrose. An invertase that is located in the cell wall may regulate the unloading of sucrose from the phloem and control assimilate accumulation whereas an invertase located in the vacuole may regulate sucrose and hexose storage. Invertase genes cloned from potato, encoding cell wall and vacuolar forms, will be integrated into two strawberry cultivars, Symphony and Senga Sengana, via Agrobacterium tumefaciens. Transgenic plants will be assessed for modified growth, sugar balance, flavour and processing quality.