Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2005
Publication Date: 2/20/2006
Citation: Rancher, G., Smart, C.D., Simko, I., Bonierbale, M., Mayton, H., Greenland, A., Fry, W.E. 2006. Characterization and mapping of rpi-ber, a novel potato late blight resistance gene from solanum berthaultii. Theoretical and Applied Genetics. 112(4):674-687. Interpretive Summary: Late blight is a serious disease of potato caused by Phytophthora infestans. Genes that confer resistance to the pathogen have been extensively studied. So far eleven major resistance genes have been introgressed into the cultivated potato from Solanum demissum. Here, we characterize RPi-ber, the resistance gene originating from S. berthaultii. Our results with a set of P. infestans isolates indicate that RPi-ber differs from the other known R-genes.
Technical Abstract: Phytophthora infestans, the causal agent of late blight, threatens potato production worldwide. An important tool in the management of the disease is the use of resistant varieties. Eleven major resistance genes have been identified and introgressed from Solanum demissum. However, new sources of resistance are continually sought. Here, we report the characterization and refined genetic localization of a resistance gene previously identified as Rber in a backcross progeny of Solanum tuberosum and Solanum berthaultii. In order to further characterize Rber, we developed a set of P. infestans isolates capable of identifying each of the 11 R-genes known to confer resistance to late blight in potato. Our results indicate that Rber is a new resistance gene, different from those recognized is S. demissum, and therefore, it has been named RPi-ber according to the current system of nomenclature. In order to add new molecular markers around RPi-ber we used a PCR-based mapping technique, named MASP-map, which located RPi-ber in a 3.9 cM interval between markers CT240 and TG63 on potato chromosome X. The location of RPi-ber coincides with an area involved in resistance to different pathogens of potato and tomato.