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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #419703
Research Project: Genetic Improvement of Lettuce, Spinach, Celery, Melon, and Related Species

Location: Crop Improvement and Protection Research

Title: Registration of six lettuce breeding lines with resistance to Fusarium wilt race 1

Author
item Richardson, Kelley
item McCreight, James
item Nayak, Santosh

Submitted to: Journal of Plant Registrations
Publication Type: Germplasm Registration
Publication Acceptance Date: 12/23/2024
Publication Date: 4/6/2025
Citation: Richardson, K.L., McCreight, J.D., Nayak, S. 2025. Registration of six lettuce breeding lines with resistance to Fusarium wilt race 1. Journal of Plant Registrations. 19(1). Article e220423. https://doi.org/10.1002/plr2.20423.
DOI: https://doi.org/10.1002/plr2.20423

Interpretive Summary: Lettuce contributes greatly to California’s economy, valued at over three billion dollars in 2022. Fusarium wilt, a disease caused by a soilborne fungal pathogen, is a major concern for lettuce worldwide. While four pathogenic races of this pathogen are recognized, the US has only dealt with Fusarium wilt race 1 until now. Planting lettuce resistant to Fusarium wilt is the best and most sustainable way to control the disease. This research provides six new lettuce lines with high levels of resistance to Fusarium wilt, which will benefit lettuce growers’ by reducing production losses.

Technical Abstract: Lettuce (Lactuca sativa L.) is a billion-dollar industry in the United States, with California producing over 90% of the nation’s supply. Fusarium wilt (FW), caused by Fusarium oxysporum f. sp. lactucae (Fol) race 1, is a major disease of lettuce worldwide. Genetic resistance is the most sustainable production practice for FW control. With the objective of combatting this ongoing challenge, we report the registration of six breeding lines: 15631 (Reg. no. ___, PI 691904), 15632 (Reg. no. ___, PI 691905), 15633 (Reg. no. ___, PI 691906), 15634 (Reg. no. ___, PI 691907), 15669 (Reg. no. ___, PI 691908), and 15670 (Reg. no. ___, PI 691909) with resistance to Fol race 1. These were developed and released by the USDA-ARS from a cross between ‘King Louie’ (romaine type; highly resistant to Fol race 1) and ‘Autumn Gold’ (crisphead type; susceptible to Fol race 1). They were selected using a pedigree selection breeding method through a series of greenhouse and field evaluations. Disease severity was assessed using a standardized visual rating scale (1, no disease to 4, dead plant), with the released lines exhibiting significantly lower FW severity and incidence compared to susceptible checks. These breeding lines have shown stable and uniform resistance to FW race 1 in multiple trials and offer an essential genetic resource for lettuce breeders and seed companies. Preliminary greenhouse results suggest they are also resistant to novel pathogenic Fol isolates, recently detected in California. These lines are available for research and to incorporate Fol race 1 resistance into elite lines, contributing to sustainable lettuce production in impacted regions.