Resistance to Colletotrichum lindemuthianum in Phaseolus vulgaris: a case study for mapping two independent genes

• Published in: Theoretical and applied genetics 2008-02, Vol.116 (3), p.407-415
• Main Authors: Geffroy, Valérie, Sévignac, Mireille, Billant, Paul, Dron, Michel, Langin, Thierry
• Format: Article
• Language: English
• Subjects: Agriculture; Beans; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; Case studies; Chromosome Mapping; Classical genetics, quantitative genetics, hybrids; Colletotrichum - physiology; Colletotrichum lindemuthianum; Flowers & plants; Fundamental and applied biological sciences. Psychology; Genes; Genes, Plant; Genetics of eukaryotes. Biological and molecular evolution; Genomes; Genomics; Genotype; Genotype & phenotype; Hypotheses; Immunity, Innate - genetics; Immunity, Innate - immunology; Inbreeding; Life Sciences; Likelihood Functions; Lod Score; Methods, theories and miscellaneous; Original Paper; Pathogens; Phaseolus - genetics; Phaseolus - microbiology; Phaseolus vulgaris; Phenotype; Plant Biochemistry; Plant Breeding/Biotechnology; Plant diseases; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Genetics and Genomics; Pteridophyta, spermatophyta; Segregation; Vegetals
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-007-0678-y

Anthracnose, caused by the hemibiotrophic fungal pathogen Colletotrichum lindemuthianum is a devastating disease of common bean. Resistant cultivars are economical means for defense against this pathogen. In the present study, we mapped resistance specificities against 7 C. lindemuthianum strains of various geographical origins revealing differential reactions on BAT93 and JaloEEP558, two parents of a recombinant inbred lines (RILs) population, of Meso-american and Andean origin, respectively. Six strains revealed the segregation of two independent resistance genes. A specific numerical code calculating the LOD score in the case of two independent segregating genes (i.e. genes with duplicate effects) in a RILs population was developed in order to provide a recombination value (r) between each of the two resistance genes and the tested marker. We mapped two closely linked Andean resistance genes (Co-x, Co-w) at the end of linkage group (LG) B1 and mapped one Meso-american resistance genes (Co-u) at the end of LG B2. We also confirmed the complexity of the previously identified B4 resistance gene cluster, because four of the seven tested strains revealed a resistance specificity near Co-y from JaloEEP558 and two strains identified a resistance specificity near Co-9 from BAT93. Resistance genes found within the same cluster confer resistance to different strains of a single pathogen such as the two anthracnose specificities Co-x and Co-w clustered at the end of LG B1. Clustering of resistance specificities to multiple pathogens such as fungi (Co-u) and viruses (I) was also observed at the end of LG B2.