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

Authors: URREA, CARLOS - University Of Nebraska; Smith, James - Rusty; Porch, Timothy - Tim

Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/26/2021
Publication Date: 5/11/2022
Citation: Urrea, C.A., Smith, J.R., Porch, T.G. 2022. Registration of drought tolerant pinto SB-DT2 and small red SB-DT3 common bean germplasm from a shuttle breeding program between Nebraska and Puerto Rico. Journal of Plant Registrations. 16:400-409. https://doi.org/10.1002/plr2.20196.
DOI: https://doi.org/10.1002/plr2.20196

Interpretive Summary: Drought stress is a significant constraint to common dry bean production in the U.S. and internationally. In the U.S., there are multiple market classes of common dry beans, including pinto, small red, dark red kidney, light red kidney, white kidney, great northern, small white, small black, pink, cranberry, and others. The purpose of this research was to develop pinto and small red dry beans that are tolerant to drought stress. The dry beans were developed collaboratively between the University of Nebraska and the U.S. Department of Agriculture, Agricultural Research Service, by alternating the development and testing sites of the beans between the two locations. SB-DT2 is the name of the pinto bean and SB-DT3 is the name of the small red bean. From 2012 to 2018, the new pinto bean SB-DT2 had the highest seed yield compared to drought tolerant dry beans SB-DT1, TARS-MST1, and Matterhorn, performing well in both drought and non-drought environments. The new small red bean SB-DT3 had the third highest seed yield overall, which was still greater than the small red variety Merlot. In addition to drought stress tolerance, SB-DT2 and SB-DT3 showed resistance to naturally occurring strains of common bean rust at Fort Collins, CO. Also, SB-DT2 carries a single dominant gene that provides partial resistance to the bean common mosaic virus (BCMV). Under drought stress, SB-DT2 and SB-DT3 flowered at 44 and 46 days after planting, respectively, and matured 86 and 88 days after planting, respectively. These two new dry beans will be used by common bean breeders in the U.S. and internationally, to develop improved drought tolerant varieties for farmers around the world in the pinto and small red market classes. They may also be used by research scientists studying drought, and as measures of drought tolerance in comparison to other beans.

Technical Abstract: Drought stress is an increasingly prevalent constraint to common bean production in the U.S. and internationally. SB-DT2 (Reg. No. GP-____, ____) is a pinto bean germplasm and SB-DT3 (Reg. No. GP-____, ____) is a small red bean germplasm developed through shuttle breeding between Nebraska and Puerto Rico with broad temperate and tropical adaptation. These germplasms 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 to the drought checks SB-DT1, TARS-MST1, and Matterhorn from 2012 to 2018, meaning that they 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 by Uromyces appendiculatus. SB-DT2 carries the single dominant hypersensitive I gene that provides strain non-specific resistance to the bean common mosaic virus (BCMV). The Intertek snpPV0072 confirmed the presence of the I gene, while the absence of the bc3 gene was confirmed with the eIF4E CAPS marker. Under drought stress, SB-DT2 and SB-DT3 flowered at 44 and 46 d, respectively, and matured 86 and 88 d after planting, respectively, and are adapted to both temperate and tropical production environments. This germplasm was developed cooperatively by the University of Nebraska and the USDA-ARS.