Evaluation Of Ancestral Lines Of Us Soybean Cultivars For Resistance To Four Soybean Viruses

Fifty-two North American (NA) ancestral soybean [Glycine mar (L.) Merr.] lines were screened for resistance to Bean pod mottle virus (BPMV), Soybean mosaic virus (SMV) strains G1 and G5, Tobacco ringspot virus (TRSV), and Tobacco streak virus (TSV). Seven ancestors, 'CNS', 'Haberlandt', 'Ogden', 'Peking', PI 71506, PI 88788, and 'Tokyo', were resistant to SMV-G1. Sixteen entries, 'A.K. (Harrow)', 'Capital', CNS, FC 33243, Haberlandt, 'Illini', 'Improved Pelican', 'Laredo', 'Lincoln', 'Mandarin', 'Mandarin (Ottawa)', Ogden, 'Palmetto', Peking, PI 88788, and Tokyo were resistant to SMV-G5. All ancestral lines tested were susceptible to BPMV and TRSV. Only one ancestor, 'Tanner', was resistant to TSV. On the basis of cultivar registration articles through 2002, there were 15 public soybean cultivars with reported resistance to SMV. The possible donors of resistance for each were identified. Two soybean ancestors, CNS and Ogden, were the most important possible sources of SMV resistance genes in U.S. commercial soybean cultivars, as the pedigree of 75 and 56% of the reported resistant cultivars contained CNS and Ogden, respectively. In most of the cultivar registration articles, reactions to SMV were not reported. With the relatively high frequency of SMV resistance in major ancestral lines, SMV resistance in U.S. cultivars may be more common than expected.