Submitted to: Eucarpia Conference on Lettuce and Leafy Vegetables
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2007
Publication Date: April 19, 2007
Citation: Simko, I., Hu, J. 2007. Effect of Population Structure on Association Mapping in Cultivated Lettuce. In Eucarpia Leafy Vegetables 2007 Conference Abstracts. Warwick, UK, April 18-20, 2007. Technical Abstract: Association mapping is a novel method for detecting linkage between molecular markers and the trait of interest in existing cultivars. However, an unrecognized population structure in a set of analyzed cultivars might lead to spurious associations. To observe how population structure affects marker-trait association, fifty-four lettuce cultivars were assayed with 388 TRAP marker loci and evaluated for four phenotypic traits. The traits with a strong relationship to population structure (lettuce dieback resistance and head height) displayed many false positive results; however, the spurious associations disappeared when population structure was included into the statistical model. The false positive associations were negligible in the two traits (seed color and leaf margin undulation) with weak correlation to population structure.