Location: Plant Germplasm Introduction and Testing Research
Title: Lettuce NPGS germplasm – Verticillium Wilt resistanceAuthor
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HELLIER, BARBARA - Retired ARS Employee |
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Cornwall, Alex |
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Warburton, Marilyn |
Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 5/15/2024 Publication Date: 5/21/2024 Citation: Hellier, B.C., Cornwall, A.M., Warburton, M.L. 2024. Lettuce NPGS germplasm – Verticillium Wilt resistance. In: Volk, G.M., Chen, K., Byrne, P., editors. Plant Genetic Resources: Success Stories. Fort Collins, CO: Colorado State University. https://colostate.pressbooks.pub/pgrsuccessstories/chapter/lettuce-npgs-germplasm-verticillium-wilt-resistance/. Interpretive Summary: Verticillium Wilt, caused by Verticillium dahlia Kleb. is a severe disease in lettuce (Lactuca sativa L) and has caused crop loss in whole fields in the Salinas and Pajaro Valleys, California, part of the prime lettuce growing region in the US. The farm gate value of lettuce in this area (Santa Cruz and Monterey counties, CA) was $1.4 billion in 2022 with half of the production in head lettuce (iceberg type). All lettuce types are susceptible to Verticillium Wilt but iceberg lettuce is the most affected. This e-book chapter highlights efforts by USDA ARS National Plant Germplasm System (NPGS) staff and plant breeders, who successfully identified 7 sources of resistance to Verticillium Wilt from the NPGS genebank in Pullman, Washington, and created new breeding lines to move this resistance into new cultivars for U.S. farmers. Technical Abstract: Verticillium Wilt, caused by Verticillium dahlia Kleb. is a severe disease in lettuce (Lactuca sativa L) and has caused crop loss in whole fields in the Salinas and Pajaro Valleys, California, part of the prime lettuce growing region in the US. The farm gate value of lettuce in this area (Santa Cruz and Monterey counties, CA) was $1.4 billion in 2022 with half of the production in head lettuce (iceberg type). All lettuce types are susceptible to Verticillium Wilt but iceberg lettuce is the most affected. Finding sources of resistance was essential, because cultural and chemical control are not economically or environmentally friendly options. In 2004 and 2005 researchers at the USDA-ARS Crop Improvement and Protection Research Station, Salinas, CA conducted resistance screening trials of a wide range of lettuce lines including accessions from the USDA-ARS Western Regional Plant Introduction Station. The researchers found 7 Plant Introduction accessions, which are older cultivars now maintained in the genebank, with resistance to Verticillium Wilt Race 1. Subsequently, the resistance found in the trials was used to develop iceberg lettuce breeding lines. From 2011 to present (February 2024) 148 seed requests from lettuce breeders and researchers, with 21 of the orders from international requestors, have been filled for the iceberg breeding lines developed by the USDA-ARS Salinas Station and deposited with the NPGS. From 2007 to present (February 2024) 139 seed requests have been filled for the 7 originally resistant accessions, 44 of the orders sent to international requestors. |