2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to identify molecular markers for the genes for Stemphylium blight resistance and rust, determine the epidemiology of the Stemphylium blight and Uromyces rust pathogens, and initiate marker-assisted selection for Stemphylium blight and rust resistance in lentil that can be readily adopted by breeding programs. 1b.Approach (from AD-416) Develop mapping populations of recombinant inbred lines (RILS) from crosses of rust and Stemphylium blight resistant parents with susceptible parents. Phenotype the mapping populations for reaction to rust and blight. Use bulk segregant analysis (BSA) to identify candidate markers (AFLP and SSR) for the genes for resistance to Stemphylium blight and rust. Develop a molecular map for the populations using AFLP and SSR markers. Where appropriate convert candidate markers to Sequence Characterized Amplified Regions (SCARs) that can be used efficiently in marker assisted selection. Determine the nature, distribution, and life cycles of Stemphylium blight and Uromyces rust causing pathogens. Determine environmental conditions favorable to disease development and spread of Stemphylium blight and screening protocols (both field and controlled environments) for identifying Stemphylium blight and Uromyces rust resistance in lentil germplasm and breeding lines. 3.Progress Report This is an extramural trust agreement between ARS and the International Center for Agricultural Research in the Dry Areas (ICARDA). Additional details of research can be found in the report for the parent CRIS 5348-21000-014-00D, Germplasm Enhancement, Genetics and Disease Management of Cool Season Food Legumes. Research efforts of this research agreement were focused on development of lentil recombinant inbred line (LRIL) populations for mapping disease resistance and on identification of polymorphic markers among the parents of the LRIL populations. Three LRIL populations (LRIL 21, 22 and 45) were developed for rust, stemphylium blight and sclerotinia white mold screening, respectively. Screening of these LRIL populations for the three diseases is being conducted at different locations with conditions conducive to the individual diseases. In identifying polymorphic markers for these LRIL populations, various kinds of markers were screened among the parents of the LRIL populations. Nine of 27 isozyme markers were found to be polymorphic. Eight of the nine polymorphic markers were found among the parents of the LRIL 21 and 22 populations, and only one isozyme (AAT) marker was polymorphic between the parents of the LRIL 45 population. For the LRIL 45 parents, 18 of 242 PSMPS markers, six of 900 MtSSR markers, 14 of 30 SSR markers, 26 of 126 new lentil SSR markers, five of 40 RFLP markers and two of 60 gene-specific markers showed polymorphism. For the LRIL 22 parents, 75 of 181 RAPD markers, two of 30 SSR markers and 22 of 126 new lentil SSR markers were polymorphic. These polymorphic markers along with phenotypic data of disease resistance will allow us to place resistance to rust, stemphylium blight and sclerotinia white mold onto lentil genetic map.