Crop Centre in Print
Please find the latest journal publications from the Crop Centre listed below.
For a full list of publications from the School of Life Sciences please visit the Latest Journal Publications
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.
Genomics Evolutionary History and Diagnostics of the Alternaria alternata Species Group Including Apple and Asian Pear Pathotypes
Andrew D Armitage, Helen M Cockerton, Surapareddy Sreenivasaprasad, James Woodhall, Charles R Lane, Richard J Harrison and John P Clarkson
The Alternaria section alternaria (Alternaria alternata species group) represents a diverse group of saprotroph, human allergens, and plant pathogens. Alternaria taxonomy has benefited from recent phylogenetic revision but the basis of differentiation between major phylogenetic clades within the group is not yet understood. Furthermore, genomic resources have been limited for the study of host-specific pathotypes. We report near complete genomes of the apple and Asian pear pathotypes as well as draft assemblies for a further 10 isolates representing Alternaria tenuissima and Alternaria arborescens lineages. Our findings allow identification and differentiation of apple, pear, and strawberry pathotypes, providing new tools for pathogen diagnostics.
Basal Rot of Narcissus: Understanding Pathogenicity in Fusarium oxysporum f. sp. narcissi
Andrew Taylor, Andrew D Armitage, Claire Handy, Alison C Jackson, Michelle T Hulin, Richard J Harrison and John P Clarkson
Fusarium oxysporum is a globally distributed soilborne fungal pathogen causing root rots, bulb rots, crown rots and vascular wilts on a range of horticultural plants. Pathogenic F. oxysporum isolates are highly host specific and are classified as formae speciales. Narcissus is an important ornamental crop and both the quality and yield of flowers and bulbs can be severely affected by a basal rot caused by F. oxysporum f. sp. narcissi (FON). This is the first study to characterise molecular variation in FON and provide an analysis of the FON genome. Identification of expressed genes potentially associated with virulence provides the basis for future functional studies and new targets for molecular diagnostics.
Transcriptome and organellar sequencing highlights the complex origin and diversification of alloteraploid Brassica napus
Hong An, Xinshuai Qi, Michelle L. Gaynor, Yue Hao, Sarah C. Gebken, Makenzie E. Mabry, Alex C. McAlvay, Graham R. Teakle, Gavin C. Conant, Michael S. Barker, Tingdong Fu, Bin Yi, and J. Chris Pires
Brassica napus, an allotetraploid crop, is hypothesized to be a hybrid from unknown varieties of Brassica rapa and Brassica oleracea. Despite the economic importance of B. napus, much is unresolved regarding its phylogenomic relationships, genetic structure, and diversification. Here we conduct a comprehensive study among diverse accessions from 183 B. napus (including rapeseed, rutabaga, and Siberian kale), 112 B. rapa, and 62 B. oleracea and its wild relatives. This study highlights the complex origin and evolution of B. napus providing insights that can further facilitate B. napus breeding and germplasm preservation.
Susceptibility of Myzus persicae, Brevicoryne brassicae and Nasonovia ribisnigri to Fungal Biopesticides in Laboratory and Field Experiments
Gill Prince, Dave Chandler
The aim of this study was to evaluate the potential of entomopathogenic fungi (EPF) for the control of aphid pests of field vegetable crops.
Four biopesticides based on the EPF Beauveria bassiana (Botanigard ES and Naturalis L), Cordyceps fumosorosea s.l. (Preferal WG), and Akanthomyces dipterigenus (Vertalec) were evaluated in a laboratory bioassay against peach-potato aphid Myzus persicae, cabbage aphid Brevicoryne brassicae, and currant-lettuce aphid Nasonovia ribisnigri.
There was significant variation in the spore dose provided by the products, with Botanigard ES producing the highest dose (639 viable spores per mm2). Botanigard ES also caused more mortality than the other products. Combining Vertalec with the vegetable oil-based adjuvant Addit had an additive effect on the mortality of B. brassicae. All fungal products reduced the number of progeny produced by M. persicae but there was no effect with B. brassicae or N. ribisnigri. When aphid nymphs were treated with Botanigard ES and Preferal WG, both products reduced population development, with up to 86% reduction occurring for Botanigard ES against M. persicae. In a field experiment, Botanigard ES sprayed twice, at seven-day intervals, against B. brassicae on cabbage plants, reduced aphid numbers by 73%. In a second field experiment with B. brassicae, M. persicae, and N. ribisnigri, Botanigard ES reduced populations of B. brassicae and N. ribisnigri but there was no significant effect on M. persicae.