Restriction Fragment Length Polymorphism Mapping of the Stemphylium Resistance Gene in Tomato. J. Behare. The Hebrew University of Jerusalem, The Faculty of Agriculture, Department of Field and Vegetable Crops and the Otto Warburg Center for Biotechnology in Agriculture, Rehovot 76100 Israel. H. Laterrot(2), M. Sarfatti(1), and D. Zamir(1). (1)The Hebrew University of Jerusalem, The Faculty of Agriculture, Department of Field and Vegetable Crops and the Otto Warburg Center for Biotechnology in Agriculture, Rehovot 76100 Israel, and (2)Station d’Amelioration des Plantes Maraichres, INRA, Avignon, Montfavet, France.. MPMI 4:489-492. Accepted 30 April 1991. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1991.

The resistance of tomato (Lycopersicon esculentum) to the gray leaf spot disease caused by four Stemphylium species is conferred by a single incompletely dominant gene, Sm. The resistance gene was introgressed into cultivars from the wild species L. pimpinellifolium and was found to be linked to a Fusarium race 1 resistance gene on chromosome 11. To place Sm on the restriction fragment length polymorphism (RFLP) map, we analyzed by means of progeny tests the genotypes of 124 F2 plants segregating for the resistance. The results were compared to the RFLP genotypes of the plants with respect to eight DNA markers that map to chromosome 11. Sm was located between T10 and TG110. The linkage between T10 and Sm was not broken in eight independently bred resistant lines that showed the same polymorphism as the donor L. pimpinellifolium accession. The results indicate the usefulness of RFLP markers for screening of plants for Stemphylium resistance and as potential starting points in a chromosome walk aimed at cloning Sm.