‘Guardians from the Grass’; Harnessing fungal endophytes to suppress plant parasitic nematodes of potatoes (Ref: CTP-SAI-081)

Globally, ca.374 million tons of potatoes are produced per annum, providing a staple food that is rich in carbohydrate, protein, fibre and vitamin C (FAO, 2024). Several plant parasitic nematodes pose a threat to potato crops cultivated in the UK. Potato cyst nematodes (PCN; Globodera pallida and G. rostochiensis) are quarantine pests that prevent seed production in contaminated land and limit yields in susceptible ware crops. Stubby root nematodes (SRN; Trichodorus and Paratrichodorus spp.) are equally important, especially on lighter soils (80-90% sand fraction), where they are more prevalent. Root feeding by SRN can cause stunted growth and patchy emergence. Additionally, the nematodes can vector tobacco rattle virus (TRV), causing malformations and spraing (necrotic arcing in the flesh of tubers). Management of PCN and SRN typically requires nematicides, such as fosthiazate and fluopyram. While fosthiazate is registered until July 2029, there are concerns about its future in light of revocation of two similar compounds in the last 5 years (ethoprophos and oxamyl). Epichloë spp. are endophytic fungi, that form symbiotic relationships with grasses. The endophyte colonises the host apoplast, taking nutrition through cell walls. Grasses with Epichloë spp. benefit from physiological benefits (increased growth), antioxidant production, which minimises stress, and protection against pests and pathogens via secreted alkaloids e.g. lolines. Alkaloids secreted by Epichloë, accumulate in roots, shoots and seeds, and can be released through root exudates. These compounds have been recorded to be nematostatic and nematicidal to plant parasitic nematodes (Mwangi et al., 2024). Unpublished work from Harper Adams University (Nyambura Mwangi – PhD) revealed that extracts from Festulolium grass and seed infected with Epichloë increased the mortality of the SRN Trichodorus primitivus, under in-vitro conditions. Differences in mortality were observed with extracts collected from grasses at different periods after planting; 8-week-old plants gave the greatest effect (1250-5000 µg/ml resulted in ca.70-100% mortality). Similarly, grass that was mechanically bruised increased the degree of mortality. Furthermore, modest reductions (ca. 24% reduction) in PCN egg viability were observed where cysts were buried in potting medium where Epichloë infected grasses were cultivated and incorporated (Williams and Back, unpublished). Although these findings are encouraging, further work is required to validate the strategy under UK field conditions and determine its optimal application

SUPERVISORS

Dr Matthew Back (Harper Adams University), Dr Katrzyna Dybal (Harper Adams University) and Dr Sarah Roberts (NIAB / CUPGRA)

PRIMARY LOCATION OF THIS PHD

The student will be registered and based with Harper Adams University

TRAINING

The student will benefit from complimentary training and guidance provided by Harper Adams University, NIAB and CUPGRA. The NIAB Farming Systems team includes researchers who specialise in potato agronomy and physiology, and rotations and soil health. They will support the project by ensuring that the work is set rightly within the potato farming rotational context and provide coaching for sharing findings with farmers. CUPGRA is a community interest company consisting of farmers, agronomists and other members of the industry interested in improving their potato production through research and is a vast network of contacts within the potato sector ready to support research through a variety of mechanisms. The project will include a mixture of field, glasshouse and laboratory-based work, providing practical skills in agronomy, nematology, molecular biology, microscopy and data analysis.

The CTP – SAI (https://www.ctp-sai.org) is a groundbreaking partnership between leading businesses, charities and research providers offering outstanding training for the agri-food sector. Students will have access to training opportunities through their University to complement their scientific development. This will be augmented by training in key bioscience skills to enhance employability and research capability through the CTP-SAI.

There will be additional training to enhance employability and research capability. All CTP-SAI students will receive Graduate Training in Leadership and Management as well as personal development skills training from MDS (www.mds-ltd.co.uk).

INDUSTRIAL PLACEMENT

Placements are a key feature of CTP and UKRI-BBSRC expects all doctoral candidates on a CTP programme to undertake a placement. Placements can be in the form of research placements (3-18 months duration) or used more flexibly for experiential learning of professional skills for business and/or entrepreneurship. All placements are developed in collaboration between the partners with input from the doctoral candidate.

APPLICATION AND ELIGIBILITY

Contact Dr Matthew Back (mback@harper-adams.ac.uk) for an informal discussion on the research content of this PhD.

This studentship will begin in October 2025. The successful candidate should have (or expect to have) an Honours Degree (or equivalent) with a minimum of 2.1 in Plant Science, Applied Statistics, or other related science subjects. Students with an appropriate Masters degree are particularly encouraged to apply.

We welcome UK, EU, and international applicants. Candidates whose first language is not English must provide evidence that their English language is sufficient to meet the specific demands of their study. Candidates should check the requirements for each host organization they are applying to, but IELTS 6.5 (with no component below 6.0) or equivalent is usually the minimum standard.

This studentship is for four years and is fully funded in line with UKRI-BBSRC standard rates. These were for 2024/25, an annual maintenance stipend of £19,237, fee support of £4,786, a research training support grant of £5,000 and conference and UK fieldwork expenses of £300.

To be classed as a home student, candidates must meet the following criteria and the associated residency requirements:

• Be a UK National or,
• Have settled status or,
• Have pre-settled status or,
• Have indefinite leave to remain or enter
• Be an Irish National

If a candidate does not meet the criteria above, they would be classed as an international student and must demonstrate the ability to meet the supplement in fees required for an international student.

Anyone interested should complete the online application form before the deadline of 5th January 2025. interviews will be held during January and February 2025.

Please contact recruitment-ctp-sai@niab.com for further application details.

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