Release of drought‐tolerant pinto SB‐DT2 and small red SB‐DT3 common bean germplasm from a shuttle breeding program between Nebraska and Puerto Rico

Abstract

AbstractDrought stress is an increasingly prevalent constraint to common bean (Phaseolus vulgarisL.) production in the United States and internationally. SB‐DT2 (Reg. no. GP‐310, PI 698187) is a pinto bean germplasm and SB‐DT3 (Reg. no. GP‐311, PI 698188) is a small red bean germplasm developed through shuttle breeding between Nebraska and Puerto Rico with broad temperate and tropical adaptation. These germplasm lines were developed through combining drought tolerance from the common bean Mesoamerican and Durango races and within the Mesoamerican race. SB‐DT2 had the highest geometric mean (GM) compared with the drought checks SB‐DT1, TARS‐MST1, and ‘Matterhorn’ from 2012 to 2018, meaning that it performed well under both stress and non‐stress environments. SB‐DT3 had the third highest GM, which was greater than the small red check ‘Merlot’. In addition to drought stress tolerance, SB‐DT2 and SB‐DT3 showed resistance to endemic strains of the rust pathogen at Fort Collins, CO (caused byUromyces appendiculatus). SB‐DT2 carries the single dominant hypersensitiveIgene that provides strain nonspecific resistance to theBean common mosaic virus. Under drought stress, SB‐DT2 and SB‐DT3 flowered at 44 and 46 d, respectively; matured 86 and 88 d after planting, respectively; and are adapted to both temperate and tropical production environments. These germplasm lines were developed cooperatively by the University of Nebraska and the USDA‐ARS.