ARS | Publication request: Iceberg lettuce breeding lines with resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae.

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 4, 2011
Publication Date: March 1, 2011
Citation: Hayes, R.J., Maruthachalam, K., Vallad, G.E., Klosterman, S.J., Simko, I., Luo, Y., Subbarao, K.V. 2011. Iceberg lettuce breeding lines with resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae. HortScience. 46(3):501-504.

Interpretive Summary: The Agricultural Research Service, United States Department of Agriculture and the University of California, Davis, announce the release of two iceberg seed lines of lettuce (Lactuca sativa L.). Seed lines RH08-0472 and RH08-0475 are F9 iceberg type lettuces with resistance to Verticillium wilt caused by the soil dwelling fungus Verticllium dahliae. Verticillium wilt is a serious soil disease affecting a broad range of economically important crops, including lettuce. Verticillium dahliae is seed transmitted in lettuce and other vegetable crops grown in rotation with lettuce, raising concerns regarding its spread to other lettuce production areas. While all types of lettuce are susceptible, Verticillium wilt is most damaging to iceberg type cultivars. Plants often remain symptomless until they near harvest maturity, at which time the symptoms develop quickly. Basal or “wrapper leaves” that completely cover the outer part of the head wilt, and then collapse as the disease progresses, leading to premature plant death and an unharvestable head. Other key foliar symptoms include stunting, defoliation and other developmental abnormalities. Prior to the onset of foliar symptoms, the vascular discoloration of root and stem tissues, revealed by vertical sectioning of the plant, are the only other diagnostic features. The resistant breeding developed and released by the USDA were selected from a crossing the parental lettuce cultivars ‘Tiber’ x (‘La Brillante’ x ‘Pacific’). Resistance is derived from ‘La Brillante’, a Batavia type lettuce cultivar with resistance to race 1 isolates of V. dahliae. These lettuces are suitable for commercial production in V. dahliae-infested and non-infested fields. They are being released for commercialization of Verticillium wilt resistant iceberg cultivars and for use as parents in further breeding of new resistant cultivars.

Technical Abstract: The Agricultural Research Service, United States Department of Agriculture and the University of California, Davis, announce the release of two breeding lines of lettuce (Lactuca sativa L.). Lines RH08-0472 and RH08-0475 are F9 iceberg type lettuce breeding lines with resistance to Verticillium wilt caused by V. dahliae. They were selected from the cross ‘Tiber’ x (‘La Brillante’ x ‘Pacific’). Resistance is derived from ‘La Brillante’, a Batavia type lettuce cultivar with resistance to race 1 isolates of V. dahliae. These breeding lines are suitable for commercial production in V. dahliae-infested and non-infested fields. They are being released for commercialization of Verticillium wilt resistant iceberg cultivars and for use as parents in further breeding of resistant cultivars.