Describing and using carrot genetic
diversity for breeding and research
Charlotte Allender
charlotte.allender@warwick.ac.uk
Outline
• Carrot Diversity Set background and rationale
• Field trial 2011
• Molecular Marker data
• Variation in seed/seedling vigour
• Future work
Warwick GRU Carrot Collections
Total Number of Accessions available
1533
Wild species
243
Landraces/Traditional Varieties
266
Advanced Cultivars
974
Diversity in Carrot
Taken from Rubatzky et al (1999)
Composition of Carrot Diversity Set
•Material from 35 countries
•77 accessions from WGRU
•10 experimental lines (parents of genetic mapping populations)
•Space for 7-9 elite cultivars
Wild populations
Landraces
Advanced cultivars
Parental lines of genetic
mapping populations
16 wild Daucus
31 landraces/traditional varieties
30 advanced varieties
Seed Production - Managing genetic diversity within accessions
Field Trial 2011
• Describe range of phenotypic variation in
CDS using standard descriptors
• Sown May 2011
• Harvested November 2011
• Stakeholder Open Day in October 2011
Characters Scored in Field Trial
based on standard ‘IPGRI’ descriptors
Descriptors
Leaf colour
Leaf shape
Petiole Anthocyanin
Bolting tendency
Root length
Root shape
Root shoulder and tip shape
Root skin/core/flesh colour and intensity
Position of root in soil
Open Day October 2011
Variation in root colour and shape
Investigating variation in seed vigour
• Rapid establishment essential
to compete with weeds
• Look at variation in germination
and seedling growth in diversity
set
• Seed tested produced in 2010 –
seed from primary umbels used
Methods
• Slope test – carried out at 15 oC
• Recorded time taken for:
– Germination
– Root to reach 30mm in length
– Shoot to reach 20mm in length
• Seed weight and length also
recorded
Relationship between seed weight and germination time
Relationship between seed weight and time taken for root to
reach 30mm in length
Relationship between seed weight and time taken for shoot to
reach 20mm in length
Variation between the slowest and fastest growing
accessions – days taken for roots to reach 30mm
Variation between the slowest and fastest growing
accessions – days taken for shoots to reach 20mm
Variation between the slowest and fastest germinating
accessions
Genetic Marker Analysis of Carrot
Diversity Set
• DArT markers
– Cover whole genome (data set contained
2770 markers)
– Presence/absence
• Investigate genetic structure of Diversity
Set
– Relationship of wild species to cultivated
types
PCO of data from 1899 DArT Markers
Wild D. carota and other
species
European, Australasian,
American, African, Japanese
Asian, Japanese,
Turkish
Further Work
• Molecular markers – genetic diversity in
chloroplast genome
• Production of S2 lines 2012
• Comparison of field trial results with DArT data
• Completion of seed vigour tests
Acknowledgements
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Dave Pink
Brian Thomas
Ann Baker
Mariatereasa de Cesare
Horticultural Services Staff
Thomas Nothnagel
Phil Simon
Brian Smith
Defra