Abstract Tlalnepantla 64 (PI 207262) is an important source of genes for resistance to com- mon bean anthracnose, caused by Colletotrichum lindemuthianum. However, these genes have not been fully characterized. Inheritance studies using crosses involving PI 207262 show that two inde- pendent genes confer resistance to anthracnose. Allelism tests showed that the genes are located at distinct loci from the previously identified resistance genes Co-1, Co-2, Co-3, Co-5, Co-6, and Co-10. Also, no segregation was observed in relation to Co-4, Co-4 2 , Co-9, and to the gene present in cultivar Widusa, indicating that PI 207262 harbors alleles of these genes. We conclude that PI 207262 harbors two anthracnose resistance genes, Co-4 and Co-9. The Co-4 allele of PI 207262 would be different from Co-4 and Co-4 2 and it is proposed Co-4 3 as the genetic symbol for this resistance allele. As PI 207262 is the parent of BAT 93, the Co-9 symbol represents the gene of both cultivars. Also, one allele of Co-9 gene was detected in cultivar Widusa. Keywords Anthracnose Æ Colletotrichum lindemuthianum Æ Differential cultivars Æ Phaseolus vulgaris Æ Resistance genes Introduction Anthracnose, caused by the ascomycete Colleto- trichum lindemuthianum (Sacc. and Magn.) Lams-Scrib. is one of the most important diseases of the common bean (Phaseolus vulgaris L.) in Brazil and in other bean growing regions of the world (Pastor-Corrales 1985). It has been ob- served that the high diversity of C. lindemuthia- num virulence can be correlated with the diversity of the host (Pastor-Corrales et al. 1994; Balardin and Kelly 1998). Different anthracnose resistance genes present in the differential cultivars (Pastor- Corrales 1992) have been identified and new gene A. L. Alzate-Marin (&) Departamento de Gene ´ tica, Laborato ´ rio de Gene ´ tica Vegetal, Universidade de Sa ˜o Paulo (USP), Av. Bandeirantes 3900, 14049-900 Ribeira ˜ o Preto, SP, Brazil e-mail: anaalzate@rge.fmrp.usp.br A. L. Alzate-Marin Æ K. A. de Souza Æ M. G. de Morais Silva Æ E. J. de Oliveira Æ M. A. Moreira Æ E. G. de Barros Instituto de Biotecnologia Aplicada a ` Agropecua ´ ria—BIOAGRO, Universidade Federal de Vic ¸osa (UFV), 36571-000 Vic ¸osa, MG, Brazil M. A. Moreira Departamento de Bioquı´mica e Biologia Molecular, UFV, Vic ¸osa, MG, Brazil E. G. de Barros Departamento de Biologia Geral, UFV, Vic ¸osa, MG, Brazil Euphytica (2007) 154:1–8 DOI 10.1007/s10681-006-9253-x 123 Genetic characterization of anthracnose resistance genes Co-4 3 and Co-9 in common bean cultivar tlalnepantla 64 (PI 207262) Ana Lilia Alzate-Marin Æ Krystyano Almeida de Souza Æ Marcelo Geraldo de Morais Silva Æ Eder Jorge de Oliveira Æ Maurilio Alves Moreira Æ Everaldo Gonc ¸alves de Barros Received: 29 June 2006 / Accepted: 8 August 2006 / Published online: 1 February 2007 Ó Springer Science+Business Media B.V. 2007