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)

Wild populations

Landraces

Advanced cultivars

Parental lines of genetic

mapping populations

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

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

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

based on standard ‘IPGRI’ descriptors

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

Wild D. carota and other

species

Asian, Japanese,

Turkish

European, Australasian,

American, African, Japanese

PCO of data from 1899 DArT Markers

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

• Dave Pink

• Brian Thomas

• Ann Baker

• Mariatereasa de Cesare

• Horticultural Services Staff

• Thomas Nothnagel

• Phil Simon

• Brian Smith

• Defra