Yield, quality and shelf-life problems in lettuce due to virus infections in the UK

Lettuce plants across the UK are being quietly hollowed out by viruses that rot their leaves on the shelf and slash harvests, yet no one has systematically counted which viruses are doing the damage or how much they cost growers. The problem is a blind spot. UK lettuce growers know their crops are infected, but the last comprehensive survey of lettuce viruses was decades ago. Since then, new viruses have emerged, and global trade has shuffled viral populations. Without knowing exactly which pathogens are present—and how they interact—breeders cannot develop resistant varieties, and growers cannot target their control measures. This project will sequence the entire viral community (the virome) in UK lettuce fields, identify the dominant species, and measure their individual effects on yield, quality, and how quickly harvested lettuce rots. If successful, the work will give breeders a clear target: resistance genes against the most damaging virus, TuYV, which the team will search for in wild lettuce relatives. The immediate impact is practical—fewer wasted crops, longer shelf-life for supermarkets, and reduced reliance on chemical controls. The fundamental science component—characterising viral diversity in a major crop system—also provides a baseline for monitoring future viral threats as climate and trade patterns shift.