Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2005
Publication Date: June 1, 2005
Citation: Pastor-Corrales, M. A. 2005. Genetics of resistance to Uromyces appendiculatus in a unique common bean plant introduction from the Andean gene pool. Phytopathology 95: Technical Abstract: Phaseolus vulgaris plant introduction (PI) 260418 is the first Andean bean with broad resistance to U. appendiculatus. This bean accession from Bolivia is resistant to all but one of the 90 races of the bean rust pathogen that have been identified at Beltsville, Maryland. The Andean beans “Early Gallatin”, which has the Ur-4 rust resistance gene, and “Golden Gate Wax”, which has Ur-6, are resistant to only 30 and 22 of the same 90 races, respectively. PI 260418 is susceptible only one race collected from an Andean bean in the state of Colorado. The large-seeded (> 60 g/100 seeds), photoperiod-sensitive PI 260418 was crossed with bean “Pinto 114”, a Middle American bean that is susceptible to 89 of the 90 races at Beltsville. Inheritance and segregation analysis based on the reaction of the parents, F1, F2, and backcross populations to 14 races of the rust pathogen, reveal that an unlinked locus in PI 260418, different from Ur-4, confers monogenic resistance to the races of U. appendiculatus used in this study. When PI 260418 was crossed with Early Gallatin to determine genetic relationship among these two rust resistance sources, recovery of susceptible individuals in F2 populations confirmed that PI 260418 and Early Gallatin possess different rust resistance genes at unlinked loci.