VIEW ARTICLE | DOI: 10.1094/MPMI-6-348
Two Complex Resistance Loci Revealed in Tomato by Classical and RFLP Mapping of the Cf-2, Cf-4, Cf-5, and Cf-9 Genes for Resistance to Cladosporium fulvum. D. A. Jones. Sainsbury Laboratory, John Innes Centre for Plant Science Research, Colney Lane, Norwich, NR4 7UH, England. M. J. Dickinson, P. J. Balint-Kurti, M. S. Dixon, and J. D. G. Jones. Sainsbury Laboratory, John Innes Centre for Plant Science Research, Colney Lane, Norwich, NR4 7UH, England.. MPMI 6:348-357. Accepted 9 March 1993. Copyright 1993 The American Phytopathological Society.
Additional Keywords: Lycopersicon esculentum, tomato leaf mold.
To develop effective strategies for cloning tomato genes for resistance to Cladosporium fulvum, we have tested the reported genetic locations of four such Cf genes. Cf-2 has been reported to be on chromosome 6, Cf-4 on chromosome 1, Cf-5 on chromosome 4, and Cf-9 on chromosome 10. Our mapping studies confirm that Cf-2 is on chromosome 6. Cf-5 is not on chromosome 4, but on chromosome 6 at the same location as Cf-2. Classical mapping places both Cf-2 and Cf-5 approximately 2 centiMorgans (cM) proximal to yv on the long arm of chromosome 6, and less than 1 cM from tl on the short arm. Restriction fragment length polymorphism (RFLP) mapping places Cf-2 close to the chromosome 6 marker TG232. Cf-4 is on the short arm of chromosome 1, loosely linked and distal to the visible marker au Cf-9 is not on chromosome 10, but on chromosome 1 at the same location as Cf-4. Classical mapping places Cf-9 approximately 14 cM distal to au and approximately 19 cM from ses, loosely linked to the chromosome 1 markers irr, Lpg, and com, but unlinked to ms-32, imb, and br. RFLP mapping places Cf-9 between the chromosome 1 markers TG236 and TG301. Tests for allelism show that Cf-2 is allelic or very closely linked to Cf-5 and that Cf-4 is allelic or very closely linked to Cf-9.