Please find the latest journal publications from the Crop Centre listed below.
Read our articles in the Vegetable Farmer
For a full list of publications from the School of Life Sciences please visit the Latest Journal Publications
John Walsh publications
Sequence analysis of 43-year old samples of Plantago lanceolata show that Plantain virus X is synonymous with Actinidia virus X and is widely distributed
J Hammond, I Adams, A Fowkes, S McGreig, M Botermans, J van Oorspronk, M Westenberg, M Verbeek, A Dullemans, C Stijger, A Blouin, S Massart, K de Jonghe, M Heyneman, J Walsh, A Fox
Plantain virus X was first recognized by the International Committee on Taxonomy of Viruses (ICTV) as a species in the genus Potexvirus in 1982. However, because no sequence was available for plantain virus X (PlVX), abolishing the species was proposed to the ICTV in 2015. Here we report the full genome sequencing of two original isolates of PlVX, which have demonstrated the virus to be synonymous to Actinidia virus X a species previously reported from kiwifruit (Actinidia sp.) and blackcurrant (Ribes nigrum). This report additionally presents novel data on the distribution and diversity of PlVX.
Turnip mosaic virus is one of the limiting factors for declining oil content in brassica. The present studies were therefore conducted to confirm the presence of this important virus in brassica through biological and serological assays. A radish isolate of Turnip mosaic virus has been identified on the basis of biological and serological assays and results obtained for screening of brassica germplasm against Turnip mosaic virus are expected to help in ascertaining the sources of resistance against this virus.
Cordycepin, a metabolite of Cordyceps militaris, reduces immune-related gene expression in insects
Hypocrealean entomopathogenic fungi (EPF) are natural regulators of insect populations in terrestrial environments. Their obligately-killing life-cycle means that there is likely to be strong selection pressure for traits that allow them to evade the effects of the host immune system. In this study, we quantified the effects of cordycepin on insect susceptibility to EPF infection and on insect immune gene expression. The results suggest that cordycepin has potential to act as a suppressor of the immune response during fungal infection of insect hosts.
The Potential for Decision Support Tools to Improve the Management of Root-Feeding Fly Pests of Vegetables in Western Europe
Rosemary Collier, Dominique Mazzi,Annette Folkedal Schjøll, Quentin Schorpp,Gunda Thöming , Tor J. Johansen , Richard Meadow , Nicolai V. Meyling, Anne-Marie Cortesero, Ute Vogler, Michael T. Gaffney and Martin Hommes
Several important vegetable crops grown outdoors in temperate climates in Europe can be damaged by the root-feeding larvae of Diptera (Delia radicum, Delia floralis, Chamaepsila rosae, Delia platura, Delia florilega, Delia antiqua). Knowledge of pest insect phenology is a key component of any Integrated Pest Management (IPM) strategy, and this review considers the methods used to monitor and forecast the occurrence of root-feeding flies as a basis for decision-making by growers and the ways that such information can be applied. It has highlighted some current management approaches where such information is very useful for decision support, for example, the management of C. rosae with insecticidal sprays and the management of all of these pests using crop covers. There are other approaches, particularly those that need to be applied at sowing or transplanting, where knowledge of pest phenology and abundance is less necessary. Going forward, it is likely that the number of insecticidal control options available to European vegetable growers will diminish and they will need to move from a strategy which often involves using a single ‘silver bullet’ to a combination of approaches/tools with partial effects (applied within an IPM framework). For the less-effective, combined methods, accurate information about pest phenology and abundance and reliable decision support are likely to be extremely important.
A standardised bioassay method using a bench‐top spray tower to evaluate entomopathogenic fungi for control of the greenhouse whitefly, Trialeurodes vaporariorum
Eleanor L Spence, David Chandler, Steve Edgington, Shaun D Berry, Gareth Martin, Christine O’Sullivan, Claus Svendsen, Helen Hesketh
Bioassays evaluating entomopathogenic fungi (EPF) isolates for effective microbial control of whitefly are a fundamental part of the screening process for bioprotectants, but development of repeatable, robust bioassays is not straightforward. Currently, there is no readily available standardised method to test the efficacy of EPF on whitefly. Here, we describe the calibration and use of a spray tower to deliver a standardised protocol to assess EPF activity. Combining the calibrated sprayer and bioassay method provides a reliable, standardised approach to test the virulence of EPF against whitefly nymphs. This laboratory-based assay is affordable, replicable and allows the user to alter the dose of conidia applied to the target.
Phenology of the diamondback moth (Plutella xylostella) in the UK and provision of decision support for Brassica growers
Wainwright C, Jenkins S, Wilson D, Elliott M, Jukes A, Collier R
In the UK, severe infestations by Plutella xylostella occur sporadically and are due mainly to the immigration of moths. The aim of this study was to develop a more detailed understanding of the phenology of P. xylostella in the UK and investigate methods of monitoring moth activity, with the aim of providing warnings to growers. The summarised sightings by citizen scientists on a web page were accessed regularly by growers and, at present, this approach appears to be the most effective way of providing timely warnings.
IGS region polymorphisms are responsible for failure of commonly used species-specific primers in Fusarium proliferatum isolates from diseased garlic
Laura Gálvez, John P. Clarkson and Daniel Palmero
Fusarium proliferatum is a globally distributed fungal pathogen that affects a range of crop hosts and is one of the main producers of mycotoxins in foods such as fumonisins. Specific PCR primers are commonly used for detection and identification of this pathogen. The aim of this study was to validate previously published F. proliferatum‐specific primers targeting the IGS region and characterise intraspecific variation and homologous recombination events for isolates obtained from diseased garlic bulbs in Spain. Our results suggest that the IGS region may be too variable as a reliable target for F. proliferatum‐specific identification.