|Goncalves-vidigal, Maria Celeste|
|Ramos Martins, Vanusa Da Silva|
|Pastor Corrales, Marcial - Talo|
Submitted to: Biomed Central (BMC) Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2017
Publication Date: 4/18/2017
Citation: Castro, S., Goncalves-Vidigal, M., Gilio, T., Giselly, F., Valentini, G., Ramos Martins, V., Song, Q., Marta, Z., Hurtado-Gonzales, O.P., Pastor Corrales, M.A. 2017. Genetics and mapping of a new anthracnose resistance Locus in Andean common bean Paloma. Biomed Central (BMC) Genomics. 18:306. Interpretive Summary: The anthracnose disease of dry and snap beans is recurrent and widespread in the Americas and Africa, and it causes significant yield losses and seed and pod quality decline. When searching for genetic solutions to this disease, we identified a bean cultivar of Andean origin named Paloma. The Paloma cultivar was resistant to many strains of the anthracnose pathogen. Our studies showed that the resistance in Paloma was conferred by a single, dominant gene. This gene was effective in conferring resistance to the highly virulent Mesoamerican strains of the anthracnose pathogen that occur in North America, Mexico and Central America, Brazil, Argentina and in some countries of Africa. We also conducted studies that located the position of the new gene in bean DNA chromosome number 1. Two DNA markers that define the position can be used by breeders in government agencies, universities, and private institutes to develop new plant varieties with this resistance gene. These efforts are expected to help protect dry and snap beans against yield losses caused by the devastating anthracnose disease.
Technical Abstract: The Andean cultivar Paloma is resistant to Mesoamerican and Andean races of Colletotrichum lindemuthianum, the fungal pathogen that causes the destructive anthracnose disease of common bean. Remarkably, Paloma is resistant to Mesoamerican races 2047 and 3481, which are among the most virulent races of the anthracnose pathogen. These races overcome most genes conferring anthracnose resistance in common bean. The objectives of this study were to characterize, map, and examine the relationship of the resistance in Paloma with other anthracnose resistance genes. The inheritance of resistance studies for Paloma was performed in an F2 population from the cross Paloma (resistant) × Cornell 49-242 (susceptible) inoculated with race 2047 and in F2:3 families from the cross Paloma x PI 207262 (susceptible) inoculated with race 3481. The results of these studies demonstrated that a single dominant gene confers the resistance in Paloma. Allelism tests conducted using multiple races of C. lindemuthianum showed that the resistance gene in Paloma, provisionally named Co-Pa, is independent of the anthracnose resistance genes Co-1, Co-2, Co-3, Co-4, Co-5, Co-6, Co-12, Co-13, Co-14, Co-15 and Co-16. Bulk segregant analysis using the SNP chip BARCBEAN6K_3 positioned the approximate location of Co-Pa in the lower arm of chromosome Pv01. Further mapping analysis located the Co-Pa gene to a 390 kb region of Pv01 flanked by KASP markers SS82 and SS83. The Co-Pa gene in Paloma will be very valuable for the development of common bean cultivars with broad resistance to the anthracnose disease of common bean.