Genetics of flavour and texture traits in potatoes

The aims of potato breeders over the last 200 years or so have largely been to maximise yield and to improve disease resistance of the potato crop. The cooking quality and flavour of potatoes has, at best, been an after-thought. However, recent surveys have suggested that flavour is the second most important attribute (after appearance) to consumers in choosing potatoes.

Perhaps the main reason that flavour has been largely ignored by breeders is its complexity. Our perception of flavour is a synaesthetic experience that involves the sensations of taste and aroma, as well as ‘mouthfeel’, which encompasses tactile, thermal and pain senses. Other sensory interactions can also influence our perception of flavour, including visual appearance.

Solanum tuberosum group phureja potatoes are grown in the Peruvian highlands and are prized for their superior flavour characteristics.  A mass-selection scheme utilising Group Phureja and Stenotomum potatoes from the Commonwealth Potato Collection (CPC) was initiated in 1962 at SCRI. This scheme, which ran for several generations, was aimed towards improving these populations for traits such as tuber dormancy, eye depth, yield, and perhaps most importantly the ability to set tubers under long days. In 2001, this scheme yielded its first listed variety, Mayan Gold, which consistently rates highly for flavour and texture in consumer preference surveys.

To investigate the role flavour and texture characteristics have in general acceptability, we are phenotyping a large group phureja x tuberosum diploid backcross population for volatile and soluble compounds involved in aroma and taste, for texture and appearance, and for a suite of sensory traits. We are using these phenotypic data, in combination with molecular genetic map information, to identify the genomic regions influencing these traits. The next step will be to use information about biochemical pathways to look for candidate genes that will allow us to better understand the characteristics that influence potato flavour and allow us to develop marker assisted breeding techniques.