Parsnip Itersonilia –
looking for solutions?
BBSRC PhD CASE Studentship with Elsoms Seeds Ltd
Lauren Chappell
Warwick Crop Centre, University of Warwick
Identifying the problem
• Parsnips are a speciality Umbelliferous crop
within the UK.
• Cover area of 3,100ha.
• Economic value of £64M annually.
• Crop losses primarily due to cankers.
How to solve the problem?
• Cankers have been identified as the primary
cause of Parsnip losses.
• Pathogens responsible for causing lesions
identified.
• Carry out high quality research into the
epidemiology of the pathogens.
• Improve breeding using molecular techniques.
Itersonilia
• Three species of Itersonilia:
– Itersonilia pyriformis
– Itersonilia perplexans
– Itersonilia pastinacae
Itersonilia pastinacae
• Seed-borne pathogen
• Foliar Symptoms
– Necrotic lesions on leaves surrounded by a yellow halo.
• Root Symptoms
– Black cankers on shoulder/crown of root.
How do we know Itersonilia’s the problem?
• Identification of the disease in the field.
• Isolation of the pathogen from infected
leaf/root material.
• Pathogens are cultured in the lab.
• Cultures then used to reinfect parsnip
material – Koch’s postulates.
Research
• What we have:
– Parsnip Transcriptome
– Itersonilia Genome
• What we need:
– Phenotypic (observable) data
– Genotypic data
• Combining these data types for QTL mapping
Marker Technology
• Traditional Parsnip breeding methods can
take up to 18yrs.
• Using marker technology can halve this time.
• The first stage is screening Parsnip line for
resistance and susceptibility to cankers:
– Parsnip lines were screened.
– Resistance and susceptibility were assessed.
Resistance Screening Results
lesion size (cm2)
Resistance
9
8
7
6
5
4
3
2
1
0
Susceptibility
Parsnip lines
Future Work
• Further work into the pathogens causing
cankers and lesions
• Further resistance assays on parsnip lines
• Assembly of genetic maps
• Identification of markers linked to QTLs
Acknowledgements
Mrs. Sue Kennedy
Dr. Adrian Dunford
Dr. Richard Tudor
Dr. John Clarkson
Dr. Guy Barker
Dr. Graham Teakle