Registration of Pinto Bean Germplasm Line USPT-WM-12 with Partial White Mold Resistance

Pinto bean (Phaseolus vulgaris L.), the most widely grown dry bean market class across the United States, is highly susceptible to white mold disease caused by the fungal pathogen Sclerotinia sclerotiorum Lib de Bary. The USDA Agricultural Research Service, Michigan State University AgBioResearch, and the University of Nebraska Agricultural Experiment Station announce the release of USPT-WM-12 (Reg. No. GP-294, PI 668537) pinto bean germplasm line with partial resistance to white mold. USPT-WM-12 was developed by modified pedigree breeding method from the cross G99750/USPT-WM-1 and was tested as PS02-037-2 or 37-2 in early generations. In later generations, USPT-WM-12 exhibited consistently high levels of partial resistance to white mold in field and straw tests conducted by the national Bean White Mold Nursery from 2008 to 2012. USPT-WM-12 also exhibited high yield potential under white mold disease pressure in Michigan, ranking the highest for yield of 64 lines tested for two consecutive years in 2010 and 2011. USPT-WM-12 has commercially acceptable agronomic characteristics, including upright architecture and moderate maturity, but seed appearance is too dark for commercial acceptance. USPT-WM-12 is intended for use by breeders to improve partial resistance to white mold in pinto and related great northern, small red, and pink dry bean market classes representative of Race Durango.