Genetic Diversity in Brassica
Peter G Walley, Sarah Stevenson, John Carder, Fran Pitt, Liz Bailey, Helen Mayne, Kerry-Sue Peplow, Sandy
McClement, Paul Hand, David Pink, Vicky Buchanan-Wollaston, Jay Moore, Guy Barker, Graham Teakle
Brassica vegetable crops are highly diverse: cauliflower, broccoli, cabbage, Brussels sprout, kohlrabi, kale
However, the variation within each crop is more limited (Figure 1)
There is also likely to be novel variation in the wild species relatives
The Warwick Genetic Resources Unit contains thousands of Brassica accessions, but this is currently too many to study
We are making Brassica resources that capture this variation in a more research-friendly form
New genome sequencing technology is making a huge difference in what we know about these plants
Wild species x Rapid cycling line
Selfed seed
F1
Microspore culture
F2
DH lines
Figure 2. Scheme for generating wild species Brassica resources.
The F2 and doubled haploid (DH) lines will be used for mapping
traits in the Brassica genome.
Figure 1. Genetic variation in crops compared with the related
genepool. Coloured letters represent different gene variants.
Genetic analysis of diversity
Oleracea (21)
Montana(4)
0.3
Macrocarpa (17)
Brassica oleracea Diversity Set
0.2
• Initiated with 376 founder accessions
mostly sourced from the genebank
representing all vegetable crop types
• Pure breeding lines are being developed to
simplify phenotyping and genetic analysis
0.1
Cretica (8)
Bourgaei (1)
Coordinate 2
•
•
•
•
•
•
Insularis (2)
Atlantica (2)
0
Incana (10)
-0.1
Alboglabra (1)
Hilarionis (2)
-0.2
Rupestris (4)
-0.2
-0.1
0
0.1
0.2
Coordinate 1
Wild Brassica species diversity set
• These have been sourced from the UK and
Europe
• Often grow in nutritionally poor
environments
• They are naturally cross-fertile with the
Brassica crops
• However, they are difficult to get to flower
and set seed
• To provide a more usable resource we
have crossed all the lines to a rapid
flowering line that sets seed well (Figure 2)
0.3
0.4
0.5
Villosa
Figure 3. Genetic markers were used to assess the relationship
between the wild species lines. Each species forms a discrete
cluster indicating that they have a distinctive genetic basis.
Genome and transcriptome sequencing
• New DNA sequencing technology is revolutionising our
ability to understand what genes are important for
controlling traits
• We are part of a consortium that has sequenced the
Brassica genome and we have used sequencing to
determine all the genes that are switched on at 2
growth stages in over 100 different lines
Warwick Crop Centre
www.warwick.ac.uk/go/wcc