|Vidigal filho, P|
|Pastor corrales, Marcial - Talo|
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/7/2010
Publication Date: 11/28/2010
Publication URL: www.springerlink.com/content/m864k709l7x682w5/fulltext.pdf
Citation: Goncalves-Vidigal, M., Cruz, A., Garcia, A., Vidigal Filho, P., Souza, L., Pastor Corrales, M.A., Mcclean, P., Kami, J., Gepts, P. 2010. Linkage mapping of the Phg-1 and Co-14 genes for resistance to angular leaf spot and anthracnose in the common bean cultivar AND 277. Theoretical and Applied Genetics. 122:893-903. Interpretive Summary: Angular leaf spot (ALS) and anthracnose are two of the most devastating diseases of common bean. Although the development of cultivars with genetically controlled resistance is the most practical and cost-effective strategy to control these diseases, developing cultivars with effective ALS and anthracnose resistance is difficult. Both diseases are caused by highly variable pathogens that can render bean cultivars that are resistant in one location or year susceptible in another. Furthermore, the development of cultivars with resistance to both diseases has been difficult. We studied the Andean cultivar AND 277 that has one gene for resistance to ALS and another for resistance to anthracnose. Our studies found that a molecular marker which is linked to the ALS resistance gene in the AND 277 cultivar is also linked to the gene for anthracnose resistance. The molecular marker and the two genes for resistance to ALS and anthracnose resistance are located in the same region of the common bean genome. These results indicate that bean breeders may use the molecular marker to simultaneously transfer resistance to ALS and anthracnose from the bean cultivar AND 277 to their own cultivars. These results are expected to benefit bean breeders and other bean scientists working in the development of bean cultivars with simultaneous resistance to ALS and anthracnose.
Technical Abstract: The Andean common bean (Phaseolus vulgaris L.) cultivar AND 277 is an important source of disease resistance to angular leaf spot (ALS, caused by Pseudocercospora griseola) and anthracnose (caused by Colletotrichum lindemuthianum). AND 277 has the Phg-1 gene that confers resistance to eight races of P. griseola and the Co-14 allele that confers resistance to 21 races of C. lindemuthianum. The Co-1 locus is mapped on linkage group 1 of the genetic map of P. vulgaris. The Phg-1 gene has not been mapped to any linkage group of the bean genome but it is linked to the SCAR SH13 marker. This study was conducted to elucidate the genetic resistance of AND 277 to ALS and anthracnose using an F2 population derived from AND 277 x Rudá and F2:3 families derived from AND 277 x Ouro Negro crosses. Co-segregation analysis revealed that a single dominant gene in AND 277 confers resistance to the races 73 and 2047 of C. lindemuthianum and to 63-23 of P. griseola. The Co-14 and Phg-1 genes were linked to the SH13 marker in the coupling phase and mapped to linkage group 1. The Phg-1 is likely an allele of Co-14 or a new closely linked gene because Phg-1 mapped within 0.0 cM of Co-14. The mapping of the Phg-1 allele was confirmed in a second population. The great importance of the anthracnose resistance genes Co-14 and Phg-1 in breeding programs is due to the broad resistance provided by these genes particularly to the Middle American races of the ALS and anthracnose pathogens that prevail in Brazil. Due to the physical linkage in cis configuration, Co-14 and Phg-1 tend to be inherited together and can be indirectly monitored with the SH13 marker. These results have the potential to reduce both the time and costs associated with the pyramiding process.