Understanding the molecular determination of quality traits in citrus fruit (MARTIN_J17ICASE)

Citrus fruit has been cultivated in an ever-widening area since ancient times; the best-known examples are oranges, lemons, grapefruit, and limes. Most commercial citrus varieties are interspecific hybrids which are propagated vegetatively, meaning that breeding and crop improvement are very difficult. One of the most important traits in citrus fruit is acidity, which is a positive attribute in varieties such as lemon, but a negative trait in the true species, mandarin.

To understand the genetic determinants of fruit acidity at the molecular level, and to facilitate improvement through breeding where possible, we are investigating the genetic determinants of fruit acidity in citrus. This studentship will extend our understanding of how this trait is determined, by developing a functional bioassay for acidity, and using this to explore the activity of genes from different citrus germplasm accessions in determining fruit acidity. We aim to create new low acidity lines of commercial citrus varieties by genome editing, in co-operation with our industrial partners. These low acidity varieties could be used to produce low acidity, low added sugar citrus juices.