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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #362409

Research Project: Genetics and Breeding of Lettuce, Spinach, Melon, and Related Species to Improve Production and Consumer-related Traits

Location: Crop Improvement and Protection Research

Title: Marker-assisted selection in lettuce breeding

item Simko, Ivan

Submitted to: Eucarpia Conference on Lettuce and Leafy Vegetables
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2019
Publication Date: 6/26/2019
Citation: Simko, I. 2019. Marker-assisted selection in lettuce breeding. EUCARPIA Leafy Vegetables International Conference, June 24-28, 2019, Olomouc, Czech Republic.

Interpretive Summary:

Technical Abstract: Cultivated lettuce is a self-fertilizing diploid (2n = 2x = 18 chromosomes) species in the family of Compositae (Asteraceae). Development of elite lettuce cultivars is a lengthy process that involves manual cross-pollination, several rounds of selection, development of homozygous lines, and performance testing of advanced lines. Molecular markers linked to genes of interest enable more rapid and, frequently also for more accurate, selection of desirable genotypes than phenotype-based selection. This marker-assisted selection (MAS) is used by lettuce-breeding programs for identification of genotypes with the favorable combination of genes. Assays have been developed to detect genes and alleles for race specific resistances to downy mildew, Verticillium wilt race 1, Fusarium wilt race 2, corky root, lettuce mosaic, lettuce dieback, and the rate of deterioration of fresh cut lettuce. Genes associated with resistances to turnip mosaic, root downy mildew, powdery mildew, big-vein, Fusarium wilt, anthracnose, and tipburn, bolting, and other economically important traits have been mapped on the molecular linkage map of lettuce and can be used for development of MAS assays. Sequencing of lettuce genome paved the road to more rapid mapping, cloning, and functional validation of genes and for more efficient development of molecular marker-assays used in MAS of lettuce.