Simple sequence repeat DNA markers linked with genes for resistance to major diseases of common bean

Authors: VALENTINI, GISELI - Universidade Estadual De Maringá; GONCALVES-VIDIGAL, M - Universidade Estadual De Maringá; CREGAN, PERRY - Retired ARS Employee; Song, Qijian; Pastor Corrales, Marcial - Talo

Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Trade Journal
Publication Acceptance Date: 3/30/2017
Publication Date: 4/30/2017
Citation: Valentini, G., Goncalves-Vidigal, M.C., Cregan, P., Song, Q., Pastor Corrales, M.A. 2017. Simple sequence repeat DNA markers linked with genes for resistance to major diseases of common bean. Bean Improvement Cooperative Annual Report. 60:29-30.

Interpretive Summary: Diseases cause seed and quality losses in common bean. Planting bean cultivars with disease resistance is the most cost-effective strategy to manage common bean diseases. However, because of the large number of virulent strains of the pathogens that cause the rust, anthracnose, and angular leaf spot diseases, it is necessary to combine multiple genes conferring resistance to achieve durable resistance. In this study we used DNA technology to develop simple sequence repeat (SSR) markers that identified rust resistance genes Ur-4, Ur-5, and Ur-14 that together confer broad resistance to the rust fungus. We discovered that the Ur-14 gene is closely linked to two genes, one conferring resistance to anthracnose and the other conferring resistance to the angular leaf spot disease. Thus, these markers will be most useful in the development of common bean cultivars with broad resistance to three major disease of diseases of common bean.

Technical Abstract: Rust, anthracnose (ANT), and angular leaf spot (ALS) are devastating diseases of the common bean. Using cultivars with disease resistance is the most cost-effective strategy to manage these diseases. Multiple genes conferring resistance to these diseases are available to develop common bean varieties with resistance to these three diseases. However, combining several resistance genes (gene pyramiding) using traditional methodologies is laborious, and time-consuming. To accelerate and facilitate gene pyramiding, effective, inexpensive, and easy to use DNA markers are needed. Simple sequence repeat (SSR) DNA markers are effective, and easy to visualize in most laboratories in developing or developed nations. The objective of this study was to discover SRR markers closely linked to genes for resistance to the rust, ANT, and ALS diseases. We used existing new technologies for SNP genotyping to identify SSR markers closely linked with genes that confer resistance to rust, ANT, and ALS. BSA and the BARCBean6K_3 chip was used to identify many SSR markers linked to several important genes that confer resistance to the pathogens that cause rust. We identified three flanking SSR markers linked to the Ur-4 rust resistance gene. Furthermore, we have also identified two SSR markers tightly linked to Ur-5. These markers were effective in differentiating cultivars with Ur-5 from those without this gene. We also identified two SSR markers tightly linked to Ur-14. The close physical linkage between the Ur-14 and the Co-34/Phg-3 cluster ensures that these genes are inherited together. These markers would be very effective when used in marker-assisted selection.