Biology subjects

Raven, M.

Publications and source records attributed to Raven, M..

2 recordsLinked to original sources

bioRxiv2025

Globodera pallida virulence on major potato resistance has a common genetic basis across Western Europe

The potato cyst nematode Globodera pallida poses a major threat to potato production in Western Europe. Current management strategies largely depend on the use of potato varieties carrying the genetic resistance GpaVvrn. However, reports from multiple West-European countries indicate a steady rise in virulence against GpaVvrn-containing potato varieties, raising serious concerns about G. pallida control. Although recent studies have resolved the genetic basis of virulence in two Dutch G. pallida populations, it remains unclear how conserved this genetic adaptation is in populations from different regions. To investigate this, we first selected eight Dutch G. pallida populations on the GpaVvrn-containing potato variety Seresta and confirmed a previously identified virulence locus. Second, by analysing the allele frequencies of four virulence-associated SNPs in Dutch, British, and French GpaVvrn-selected G. pallida populations, we found that the same allele is consistently selected by GpaVvrn across Western Europe. Third, we analysed the propagation of eight G. pallida populations on 26 GpaVvrn-containing potato varieties and showed that a populations allele frequency of a single SNP (T173N) accurately reflects its reproduction on GpaVvrn. Fourth, we developed an allele-specific quantitative PCR (AS-qPCR) assay to determine a populations alternative allele frequency (AAF) of T173N and showed that AS-qPCR-based AAFs reliably indicate virulence levels on GpaVvrn in Dutch and German G. pallida populations. Together, these findings suggest that a common allele is consistently selected by GpaVvrn in populations from different regions across Western Europe. The AS-qPCR assay developed in this study provides a practical tool to estimate G. pallida virulence on GpaVvrn in the field, enabling field-tailored and sustainable resistance management strategies for farmers.

genetics↗

bioRxiv2021

Tracing boundaries in Eastern Antarctica: Multi-scale drivers of soil microbial communities across the hyperarid Vestfold Hills

Microorganisms are key to sustaining core ecosystem processes across terrestrial Antarctica but they are rarely considered in conservation frameworks. Whilst greater advocacy has been made towards the inclusion of microbial data in this context, there is still a need for better tools to quantify multispecies responses to environmental change. Here, we extend the scope of Gradient Forest modelling beyond macroorganisms and small datasets to the comprehensive polar soil microbiome encompassing >17, 000 sequence variants for bacteria, micro-eukarya and archaea throughout the hyperarid Vestfold Hills of Eastern Antarctica. Quantification of microbial diversity against 79 physiochemical variables revealed that whilst rank-order importance differed, predictors were broadly consistent between domains, with greatest sharing occurring between bacteria and micro-eukarya. Moisture was identified as the most robust predictor for shaping the regional soil microbiome, with highest compositional turnover or "splits" occurring within the 10 - 12 % moisture content range. Often the most responsive taxa were rarer lineages of bacteria and micro-eukarya with phototrophic and nutrient-cycling capacities such as Cyanobacteria (up to 61.81 % predictive capacity), Chlorophyta (62.17 %) and Ochrophyta (57.81 %). These taxa groups are thus at greater risk of biodiversity loss or gain to projected climate trajectories, which will inevitably disturb current ecosystem dynamics. Better understanding of these threshold tipping points will positively aid conservation efforts across Eastern Antarctica. Furthermore, the successful implementation of an improved Gradient Forest model also presents an exciting opportunity to broaden its use on microbial systems globally.

microbiology↗