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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #310035

Research Project: Genetic Enhancement of Lettuce, Spinach, Melon, and Related Species

Location: Crop Improvement and Protection Research

Title: Red leaf lettuce breeding line with resistance to corky root, 06-810

Author
item Mou, Beiquan

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2014
Publication Date: 1/30/2015
Citation: Mou, B. 2015. Red leaf lettuce breeding line with resistance to corky root, 06-810. HortScience. 50:143-144.

Interpretive Summary: A new red leaf lettuce, designated 06-810, was publicly released by the Agricultural Research Service, United States Department of Agriculture (USDA). It may be suitable for commercial production, and is suitable for use as a source of resistance to corky root in the development of new varieties with resistance to the disease. 06-810 was developed at the United States Agricultural Research Station in Salinas, California by Geneticist Beiquan Mou. Corky root-infected lettuce plants develop yellow-to-brown lesions on the roots and the lesions later become longitudinal corky ridges, restricting the absorption of water and nutrients from soil. In severely infested fields in California and Florida, yield losses from reduced head size can reach 30-70%. 06-810 was derived by conventional breeding, from hybridization between the red leaf cultivar Merlot and the iceberg cultivar Glacier that has a resistant gene. 06-810 had significantly less corky root disease than nine susceptible leaf lettuce cultivars in field-testing. It also showed moderate resistance to downy mildew, another lettuce disease. In the limited field trials grown, 06-810 has performed well in the major lettuce production region, Salinas Valley, Calif., where it produced a high percentage of plants of adequate size, shape, and uniformity. Seeds of 06-810 are available for distribution to all interested parties for research purposes, including the development and commercialization of new cultivars. Limited seed samples can be obtained by sending a request directly to the author.

Technical Abstract: The Agricultural Research Service, United States Department of Agriculture (USDA) announces the release of a breeding line of red leaf lettuce (Lactuca sativa L.), 06-810. The line may be suitable for commercial production, and is suitable for use as a source of resistance to corky root disease in the development of cultivars and germplasm. It was developed by Beiquan Mou at the United States Agricultural Research Station in Salinas, Calif. Corky root-infected plants develop yellow-to-brown lesions on the roots that later become longitudinal corky ridges. In severely infested fields in California and Florida, yield losses from reduced head size can reach 30-70%. The breeding line was derived from a cross between a red leaf cultivar Merlot and a crisphead cultivar Glacier that has cor resistant alleles. The corky root ratings of the breeding line were not significantly different from ‘Glacier’, but were significantly lower than nine susceptible leaf lettuce cultivars in field trials. The breeding line was also moderately resistant to downy mildew disease. In the limited trials grown, 06-810 has performed well in the Salinas Valley, Calif. where it produced a high percentage of plants of adequate size, shape, and uniformity. Limited samples of seed are available for distribution to all interested parties for research purposes, including the development and commercialization of new cultivars.