In new research published in The Plant Journal, Professor Caroline Dean and her team explored the molecular basis for heading date variation in broccoli.
"When we use selective plant breeding to develop a new crop variety, we can grow the plants and see the effects of that process, but we don't really know what's going on at the genetic level, what genes we're actually selecting for," she said.
Through a series of laboratory, greenhouse and field-based experiments using both broccoli and the reference plant Arabidopsis thaliana (also in the Brassicaceae family), Dean and her team were able to show that small changes in a gene called FLOWERING LOCUS C (FLC) are responsible for the range of heading dates found in different broccoli varieties.
"In previous work, we showed that Arabidopsis has adapted to many different climates by modulating how quickly the FLC gene is switched off during winter," Dean said.
"Here we have shown that when we breed broccoli varieties to head at different times of the year, we're actually selecting the same gene in broccoli, BoFLC.C2. Different versions of the gene require more or less cold before the gene is switched off and flowering can begin."
Dr Judith Irwin, a crop geneticist at the John Innes Centre and first author of the Plant Journal paper, said: "Identifying that the BoFLC.C2 gene is involved in heading time variation means we now have a target for plant breeding programs to develop new brassica varieties.
"This will be especially important in the face of climate change, because our weather patterns and climate conditions are changing and we need new vegetable varieties to be resilient to this change."
Meanwhile the Norwich-based Genome Analysis Centre (TGAC) has launched an open-access Brassica Information Portal to provide a single point of access to all data from pre-breeding trait scoring experiments performed on Brassica species, in order to better inform current breeding programmes.
TGAC project lead Dr Wiktor Jurkowski said: "With all trait information in one place, and linked with genomics data, many new connections between the plant's traits and responses in different experiments can be drawn."