Please find the latest journal publications from the Crop Centre listed below.
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For a full list of publications from the School of Life Sciences please visit the Latest Journal Publications
Quantitative trait locus mapping of resistance to turnip yellows virus in Brassica rapa and Brassica oleracea and introgression of these resistances by resynthesis into allotetraploid plants for deployment in Brassica napus.
Turnip yellows virus (TuYV) is aphid-transmitted and causes considerable yield losses in oilseed rape (OSR, Brassica napus, genome: AACC) and vegetable brassicas. We report the identification, characterisation, and mapping of TuYV resistance in the diploid progenitor species of OSR, Brassica rapa (genome: AA), and Brassica oleracea This is the first report of TuYV resistance mapped in the Brassica C genome and of an allotetraploid AACC line possessing dual resistance to TuYV originating from both of its progenitors. The introgression into OSR can now be accelerated, utilising marker-assisted selection, and this may reduce selection pressure for TuYV isolates that are able to overcome existing sources of resistance to TuYV.
First report of Turnip yellows virus in Brazil
This is the first report of TuYV in Brazil. The finding has been reported to the Ministry of Agriculture of Brazil (MAPA), which approved the notification (SEI process 21052.012367/2021-73, 66/2021/DSV/SDA). Further work is required to determine the distribution and prevalence of TuYV and its impact on brassica cultivation in Brazil.
The Evolutionary History of Wild, Domesticated, and Feral Brassica oleracea (Brassicaceae)
Makenzie E Mabry, Sarah D Turner-Hissong, Evan Y Gallagher, Alex C McAlvay, Hong An, Patrick P Edger, Jonathan D Moore, David AC Pink, Graham R Teakle, Chris J Stevens, Guy Barker, Joanne Labate, Dorian Q Fuller, Robin G Allaby, Timothy Beissinger, Jared E Decker, Michael A Gore, & J Chris Pires
Understanding the evolutionary history of crops, including identifying wild relatives, helps to provide insight for conservation and crop breeding efforts. Using newly generated RNA-seq data for a diversity panel of 224 accessions, which represents 14 different B. oleracea crop types and nine potential wild progenitor species, we integrate phylogenetic and population genetic techniques with ecological niche modeling, archaeological, and literary evidence to examine relationships among cultivars and wild relatives to clarify the origin of this horticulturally important species. Our analyses point to the Aegean endemic B. cretica as the closest living relative of cultivated B. oleracea, supporting an origin of cultivation in the Eastern Mediterranean region
Characterisation of turnip mosaic virus isolates reveals high genetic variability and occurrence of pathotype 1 in Brazil
Leilane Karam Rodrigues, Alexandre Levi Rodrigues Chaves, Elliot Watanabe Kitajima,, Renata Faier Calegario,, Katia Regiane Brunelli, Fabio Nascimento da Silva, Ricardo Harakava, John Anthony Walsh & Marcelo Eiras
Turnip mosaic virus (TuMV) infects many plant species, being the only potyvirus able to infect brassicas. Despite being considered one of the most important viruses infecting brassicas worldwide, there is little information on this virus in the Neotropical region. Aiming to fill in this gap and advance knowledge on occurrence, genetic variability, and biological aspects of TuMV in Brazil, 40 isolates were identified and characterised. Our diversity analysis suggest that a strong negative selection is acting on polyprotein coding region. We confirmed that Brazilian TuMV isolates showed high variability, which together with their ability to infect wild brassicas and to circumvent resistance genes highlight their genetic and epidemiological potential incausing damages in cultivated species of brassicas andother crops in Brazil.
Identification and Expression of Secreted In Xylem Pathogenicity Genes in Fusarium oxysporum f. sp. pisi
Sascha Jenkins, Andrew Taylor, Alison C Jackson, Andrew D Armitage, Helen J Bates, Andrew Mead, Richard J Harrison and John P Clarkson
Fusarium oxysporum is a soilborne fungal plant pathogen responsible for causing disease in many economically important crops with “special forms” (formae speciales) adapted to infect specific plant hosts. F. oxysporum f. sp. pisi (FOP) is the causal agent of Fusarium wilt disease of pea.. The main aim of this work was to characterise F. oxysporum isolates collected from diseased peas in the United Kingdom as well as FOP isolates obtained from other researchers representing different races through sequencing of a housekeeping gene and the presence of Secreted In Xylem (SIX) genes, which have previously been associated with pathogenicity in other F. oxysporum f. spp. F. oxysporum isolates from diseased United Kingdom pea plants possessed none or just one or two known SIX genes with no consistent pattern of presence/absence, leading to the conclusion that they were foot-rot causing isolates rather than FOP.
Contrasting Responses of Rhizosphere Bacterial, Fungal, Protist, and Nematode Communities to Nitrogen Fertilization and Crop Genotype in Field Grown Oilseed Rape (Brassica napus)
The rhizosphere microbiome is considered to play a key role in determining crop health. However, current understanding of the factors which shape assembly and composition of the microbiome is heavily biased toward bacterial communities, and the relevance for other microbial groups is unclear. Furthermore, community assembly is determined by a variety of factors and their relative importance and interactions remain to be elucidated. We investigated the impact of nitrogen fertilization on rhizosphere bacterial, fungal, nematode and protist communities of 10 contrasting oilseed rape genotypes in a field experiment. We found significant differences in the composition of bacteria, fungi, protist and nematode communities between the rhizosphere and bulk soil. We conclude that under field conditions soil and rhizosphere nutrient stoichiometry and crop genotype are key factors determining crop health by influencing the infection of roots by pathogenic and mutualistic fungal communities, and the connectivity and stability of rhizosphere microbiome interaction networks.