Registration of USWA‐48 and USWA‐50 Virus‐Resistant Navy Dry Bean Germplasms

Navy dry bean (Phaseolus vulgaris L.) USWA-48 (Reg. no. GP181, PI 601987) and USWA-50 (Reg. no. GP-182, PI 601988) breeding lines with resistance to all strains of bean common mosaic virus (BCMV) and curly top virus (CTV) were jointly released in November 1996 by the USDA-ARS and the Agricultural Research Center of Washington State University, the Agricultural Experiment Stations of University of Idaho, and Oregon State University. Complete resistance to all strains of BCMV and CTV is needed in the bean seed production areas of the arid Western states. Both lines carry the dominant / gene for resistance to BCMV and have stable resistance to CTV. USWA-48 is an F7-derived Fn population from the cross NY5161-W/A55. NY5-161-W is a cold-tolerant, bush-type, whiteseeded breeding line from M. Dickson of the New York State Agricultural Experiment Station at Geneva. A55 is an upright II-A (CIAT classification), black-seeded line developed by S. Singh (CIAT, Columbia) with root rot tolerance, a high tolerance to CTV, and dominant /resistance to BCMV. The most outstanding characteristic of USWA-48 is the very upright, narrow profile (Type I), similar to a soybean plant habit. Maturity of USWA-48 was 4 d later than 'Norstar' (106 d, compared with 102 d). USWA48 yield averaged 3685 kg ha", compared with 3517 kg ha" for Norstar in 3-yr preliminary trials at Prosser (1993) and Othello (1994 and 1995) in Washington. Seed size of USWA-48 is slightly larger than Norstar (21 g 100 seed", compared with 19 for Norstar). The tall and narrow profile with high-borne pods may lend itself to high-density culture (28-cm rows) or solid planting for direct mechanical harvest. Under high-density conditions, yields should be very competitive. USWA-50 is an F5-derived F9 population from the cross GH1 l/'PearP. GH-11 is a navy bean breeding line developed by D.W. Burke (USDA-ARS, Prosser, WA) with the dominant / gene for resistance to BCMV and complete CTV resistance. GH-11 did not have an acceptable seed color for commercialization so was used as a breeding line. Pearl is an upright Type I navy bean, released by the Gentec Seed Company, that is susceptible to CTV. USWA50 is an upright indeterminate plant, with medium to long runners and a tendency to lodge. USWA-50 (also tested as 93 LB-1803 in 1994 and as 94 LB-4813 in 1995) yielded well in the National Cooperative Dry Bean Nursery (CDBN) grown across 25 locations in the USA and Canada in 1994 and 1995 (1,2). USWA-50 combines high yield potential (2800 to 4040 kg ha") with early maturity (93 d, compared with 100 d for Vista). Dull white seeds, with a slightly oblong shape, are relatively small (17 g 100 seed", compared with 18 for Vista). It is highly unusual for an early bean line to also have a high yield. These lines were field-screened for four years for BCMV and CTV in our virus screening nurseries, where susceptible control cultivars are routinely 50 to 100% infected. In addition, BCMV greenhouse tests were conducted at least twice to identify the resistance genes of the host. One or more isolates from each of the seven known BCMV pathogroups were included. Known control cultivars were also included to authenticate the virus strain reactions. In addition to the dominant / gene for resistance to BCMV and complete CTV resistance, USWA-50 expressed resistance to rust [caused by Uromyces appendiculatus (Pers.:Pers.) Unger] in the 1994 and 1995 CDBN trials at North Plane, NE, and Hatton, ND. USWA-50 has been the most tolerant navy bean to the field root rot complex (caused by Fusarium solani (Mart.) Sacc., Pyihium ultimum Trow, and Rhizoctonia solani Kilhn) in our root rot tests at Prosser for several years. A limited quantity of seed of USWA-8 and USWA-50 is available for research purposes from Phillip N. Miklas, Vegetable and Forage Crop Production Research Unit, USDA-ARS, 24106 N. Bunn Rd., Prosser, WA 99350-9687. It is requested that appropriate recognition be given if these germplasms contribute to the development of a new breeding line or cultivar. Genetic material of USWA-48 and USWA-50 will be deposited in the National Plant Germplasm System, where it will be available for research purposes, including development and commercialization of new cultivars.