Development of screening assays and diagnostic techniques to assess resistance to Willow Carrot Aphid (Cavariella aegopodii) and Carrot Red Leaf Virus (CtRLV) .

L. H. K. Chappell, R. Collier, C. J. Allender, G.C. Barker and G.R. Teakle

The Willow Carrot Aphid (Cavariella aegopodii) is a major pest of carrot, parsnip and celery crops, as well as using many wild apiaceous hosts. Overwintering on willow, young aphids migrate to apiaceous plants in May where they may cause significant damage to crops, including leaf discolouration and distortion. Of greater importance to carrot growers is the transmission of a range of viruses, most notably the Carrot Red Leaf Virus (CtRLV), part of the Carrot Motley Dwarf (CMD) complex. CtRLV symptoms include reddening and yellowing of leaves and stunting, resulting in severe crop losses. Chemical control is limited, so new strategies for pest management and sources of host-plant resistance are required. This research set out to develop specific screening methods and diagnostic techniques to identify novel sources of resistance for future disease management. It forms part of the VeGIN project funded by Defra and has included plant material from the UK Vegetable Gene Bank.

 Understanding the root causes: Improving carrot virus management in the United Kingdom.

A. Fox, A. Jukes, M. Mynett, A. Fowkes, I. Vazquez Iglesias and R. Collier

Work has been ongoing to try to clarify the epidemiology of the viruses infecting carrot and to determine the factors influencing the transmission of these viruses in the UK. This study reports the results of two-years of field trials to investigate the timing of transmission of CtRLV and CYLV in the UK to correlate the timing of transmission with the migration of potential vectors such as aphids from the genus Cavariella, with the aim of identifying the key aphid species driving transmission of these viruses. Additionally, this study reports work which has been conducted to elucidate the total virome of carrots and apiaceous weeds in the UK, using this information to start to build ecological networks to indicate the source of these viruses. Together these data can be used to understand the influence of carrot agronomy in the UK on virus epidemics, and in turn can be used to better inform virus management strategies for control of key carrot viruses. This is a collaboration between Fera Science Limited and the University of Warwick. Work undertaken at Warwick Crop Centre as part of this research was funded by the AHDB as project FV 460.

Development of artificial inoculation techniques for cavity spot caused by Pythium violae to identify new management strategies.

N. Pereira, K.R. Hales, L.H.K. Chappell, A. Jukes, A. Mead, C. J. Allender, G.C. Barker and J.P. Clarkson

The soilborne oomycete Pythium violae is the principal cause of cavity spot of carrots in the UK, a disease which remains a huge challenge for carrot growers as just a few superficial lesions severely reduce crop marketability. Chemical control is limited to application of metalaxyl-M, but efficacy can be variable; hence new approaches for cavity spot disease management are required. However, this is hampered by a lack of consistent inoculation approaches for P. violae that reliably induce cavity spot disease. The aim of this research was to develop robust artificial inoculation systems in both glasshouse and field suitable for identifying alternative control products and sources of disease resistance in the future. This research has been funded by AHDB and Defra as part of the VeGIN project.

Evaluation of the entomopathogenic nematode Steinernema feltiae as a biological control agent against carrot fly (Psila rosae F.).

R. H. Binks, A. Jukes, and R. Collier

Entomopathogenic nematodes (EPNs) have been utilised in classical, conservation, and augmentative biological control programs. The vast majority of applied research has focused on their potential as inundatively applied augmentative biological control agents. Studies have included the use of EPNs to control the life stages of soil dwelling insect pests. In this collaborative study with Richard Binks from Koppert we evaluated the potential for using infective juveniles of the entomopathogenic nematode Steinernema feltiae to control the larvae of carrot fly in carrot crops under field conditions.

Decision support tools for crop protection – current options and future prospects for growers of carrot and other apiaceous crops.

T. Lukianenko, A. Kelly, M.D. Kaminiaris, Z. Tsiropoulos, J.P. Rodriguez, E. Böckmann P. Poldma and R.H. Collier

Apiaceous crops are challenged by a range of pests, pathogens and weeds. It is possible to plan in advance to avoid some of these, whilst others may require rapid responses during the growing season. This presentation and paper reviews the decision support tools available to growers of apiaceous crops, with a focus on Europe, and considers future opportunities that improvements in technology will allow. There are a good number of tools available to monitor and forecast the most significant pest insects infesting apiaceous crops. but fewer tools to assist with the management of pathogens. This is an output from ‘SmartProtect’, a Horizon2020 Thematic Network in which we have collaborated, with partners in 15 countries SmartProtect H2020 – IPM THEMATIC NETWORK (smartprotect-h2020.eu).

Counting carrots: conservation and use of Apiaceous crops – from genebank to data.

Sarah Trinder, Nick Fenby and Yilue Wen and Charlotte Allender

The UK Vegetable Genebank (UKVGB) holds a collection of ~14,000 seed samples from a range of vegetable and herb crops. The collections include apiaceous crops such as carrot, parsnip and celery and herbs like coriander and parsley. Collections of plant genetic resources are conserved to ensure current and future access to crop genetic diversity. Genebanks like the UKVGB actively support utilisation by breeders, researchers and farmers but once samples are distributed, it is challenging to keep track of use and data generated. Data generated by users is a valuable resource to support future use, aiding selection of appropriate germplasm and reducing duplication of effort. We have tracked the use of our apiaceous crops through the scientific literature as part of our work to facilitate access by potential users of the collections to existing data. We examine how UKVGB germplasm has been used to screen for key traits as well as other investigations in areas such as domestication, phylogenetics and ecogeography, highlighting the vital role played by collections of plant genetic resources in plant and crop science. The UKVGB is funded by Defra.

A window into a genebank: GRIN-Global as a tool to support use of the UK Vegetable Genebank collections.

S. Trinder, Nick Fenby, Paul Brown and Charlotte Allender.

Collections of plant genetic resources represent the valuable tool of genetic diversity, required by users such as crop breeders, plant scientists and farmers. In order to use germplasm from ex situ collections such as genebanks, potential users must first understand what material is available and make an assessment of its suitability based on the available data, and then request seeds from the relevant collection. This includes not only passport data which provides information on taxonomy, provenance and origin, but also any characterisation data, including images. Characterisation data can be in a multitude of formats, and also may have been generated by other users and published in scientific literature. We describe our use of the software tool GRIN-Global, developed collaboratively by The Crop Trust, Biodiversity International and the Agricultural Research Service of the USDA, which is a tool for collection management and provides a means for users to browse, search for and order germplasm. We are populating our installation of GRIN-Global with available data on our accessions, including images and publications, and where available we will include characterisation data. The GRIN-Global platform will also allow us to link to other data repositories to indicate which accessions have sequence or other genotypic data. Facilitating access to a range of associated data will aid users of the collection and also allow better collection management, highlighting unique material as conservation priorities. The UKVGB is funded by Defra.