Researchers at the John Innes Centre have been making progress towards identifying what makes some wheat varieties more ‘slug resistant’ than others.
This work is based on previous research that screened varieties from the centre’s Watkins collection of landrace wheat varieties. This singled out Watkins 788 as a potential front runner for ‘slug resistant’ properties after 78% of slugs demonstrated a dislike to it.
From there, the team at JIC, led by Dr Simon Griffiths, crossed Watkins 788 with commercial variety Paragon, to create 85 Recombinant Inbred Lines (RILs) for further testing.
Quantitative Trait Locus (QTL) analysis is a genetic tool that helps identify specific regions of a plant’s DNA linked to desirable traits, such as slug resistance in wheat. By combining data from field trials with lab-based genetic testing, researchers are getting closer to identifying which part of the genome influences the apparent resistance.
Researchers use DNA markers to scan the genomes of resistant and susceptible RILs. Regions consistently linked to lower slug damage are flagged. Once the QTLs are confirmed, those genetic markers can potentially be used to create new slug resistant varieties.
The centre’s Head of Entomology and Insectory Dr Victor Soria-Carrasco has run trials on these RILS using slugs that have been posted in by ‘Slug Scouts’. These are members of the public (including farmers) who collect and post containers of grey field slugs to the centre.
Dr Simon Griffiths, Group Leader and ‘Delivering Sustainable Wheat’ Programme Lead says: “Early results have highlighted a number of RILs that appear to be slug resistant, as well as those that are susceptible. Using the diverse wheat in our historic Watkins collection in these trials is really exciting, as we’re starting to see it becoming an increasingly useful resource for tackling the challenges that farmers face in the field.”
Two of these RILs as well as Watkins 788 were multiplied up for testing by six Slug Sleuth farmers who took on the additional responsibility within the SLIMERS project. The farmers established blocks of Watkins 788 and the two RILS – one believed to be resistant and the other susceptible to slugs – alongside their farm standard wheat. Over the 2024-5 growing year they have taken measurements and samples to find out if these are indeed spurned by slugs and could offer potential solutions to farmers.
Meanwhile the on-going lab-based feeding trials have identified other even more resistant RILs that are currently being multiplied up at the John Innes Centre field station near Norwich, and will be put into field trials in autumn 2025.