`Chase' Pinto Dry Bean

The release of ‘Chase’ fulfills a need in southwestern Nebraska for a Pinto dry bean cultivar (Phaseolus vulgaris L.) with resistance to rust [Uromyces appendiculatus (Pers.) Unger] and several bacterial diseases. Rust, common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye], and bacterial brown spot (Pseudomonas syringae pv. syringae van Hall) diseases have recently reduced bean yields and seed quality of Pinto dry beans in that region and northeastern Colorado. ‘Chase’ is the first Pinto cultivar that combines resistance to rust(races of rust prevalent in recent years in Nebraska and Colorado), bacterial brown spot, halo blight [P. syringae pv. phaseolicola (Burkholder)], moderate resistance to common blight, and moderate avoidance of white mold [Sclerotinia sclerotiorum (Lib.) de Bary] due to a porous canopy. ‘Chase’ also has resistance to potato leafhopper “bum” injury caused by Empoasca fabae Harris. Origin We deemed it important to develop an early maturing Pinto line with resistance to rust and common blight and with moderate avoidance to white mold. ‘Chase’ (evaluated as PWM2-89-5 from 1989 to 1992) was derived by pedigree selection (Fig. 1) from a cross of a Nebraska (NE) Great Northern (GN) breeding line GN WM2-84- 17 (upright plant habit, moderately early, resistant to common bacterial blight and rust, and moderate avoidance of white mold) and a NE Pinto (P) breeding line PWM2-84-45 (prostrate habit, early maturity, good Pinto seed size and shape, rust-resistant, but susceptible to white mold and common blight). These lines were derived from intercrosses of P and GN lines that were derived from pedigree selection from crosses of GN Nebraska #1 selection 27 (late-maturing, Type III plant habit, and resistant to common blight) (Coyne and Schuster, 1983) × ‘Tacaragua’ (Venezuela) (black seed, Type IIb plant habit, late maturity, resistant to rust races in Nebraska, and moderate avoidance of white mold) and F5BC6 GN Nebraska #l selection 27 × Pinto ‘UI-111‘ (early maturity; Type III plant habit; susceptible to rust, common blight, and white mold Fig. 1). We used the classification scheme reportedly Singh (1982) to describe growth habits of common beans. The cross GN Nebraska #1 selection 27 × ‘Tacaragua’ was made by Valladares-Sanchez et al. (1983) to study the inheritance of resistance to common bacterial blight.