Registration of ‘USDA Diamondback’ slow-darkening pinto bean

Abstract

The pinto bean (Phaseolus vulgaris L.) cultivar ‘USDA Diamondback’ (Reg. no. CV-353, PI 698822) was released by the USDA-ARS in 2022 as a high-yielding cultivar with an upright architecture and the slow-darkening seed coat trait. It was bred for tolerance to multiple abiotic stresses in a “purgatory” plot purposely managed to have compacted soil, low soil fertility, and intermittent drought conditions. Conversely, selection for high yield potential was conducted in non-stress trials with tillage, irrigations, and fertilizers applied for optimal production. USDA Diamondback exhibits wide adaption to production regions across the United States, as evidenced by an average seed yield of 3808 kg ha⁻¹ across 14 location-years in the Cooperative Dry Bean Nursery. Virus testing and resistance gene–linked markers indicate USDA Diamondback has a three-gene combination (bc-u^d, bc-1, and bc-3) that confers durable resistance to all known strains of Bean common mosaic virus and Bean common mosaic necrosis virus. A similar combination of pathogen and marker testing indicated that USDA Diamondback possesses the Ur-3 and Ur-6 genes for resistance to bean rust. The seed size, appearance, and canning quality characteristics of USDA Diamondback meets the industry standards for packaging and processing.