Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/10/2006
Publication Date: 5/15/2007
Citation: Domier, L.L., Steinlage, T.A., Hobbs, H.A., Wang, Y., Herrera-Rodriguez, G., Haudenshield, J.S., Mccoppin, N.K., Hartman, G.L. 2007. Similarities in seed and aphid transmission of soybean mosaic virus isolates. Plant Disease. 91(5):546-550. Interpretive Summary: Soybean mosaic virus (SMV) is an aphid- and seed-transmitted virus that infects soybean plants and causes significant losses in the amount and quality of seed harvested. Since SMV rarely infects alternative host species, seed-borne infections are the primary sources of inoculum for SMV infections. Controlling seed-borne SMV infections has become more important with the discovery in North America of the Asian soybean aphid, which can efficiently transmit SMV among soybean plants. In this study, we showed that the efficiency of transmission of SMV through seed was highly correlated with transmission of SMV by soybean aphids. SMVs that are efficiently transmitted both vertically and horizontally undoubtedly would be disseminated more readily than SMVs lacking one of these modes of transmission. This information will be useful to scientist studying the epidemiology of SMV and related viruses.
Technical Abstract: The strain specificity of transmission of Soybean mosaic virus (SMV) through seed and SMV-induced seed-coat mottling were investigated in field experiments. Six soybean plant introductions (PIs) were inoculated with eight SMV isolates. Transmission of SMV through seed ranged from 0% to 42.6% in seed from field-grown plants. SMV isolate-by-soybean line interactions were seen in both transmission rates and percentages of mottled seed. For example, SMV 746 was transmitted from 42.6% of field-grown seed of PI 229324, but was not transmitted through seed of PIs 68522, 68671 or 86449. In contrast, SMV 413 was transmitted through seed from all PIs. SMV isolates that were transmitted poorly by the Asian soybean aphid, Aphis glycines, also were transmitted poorly through seed of PIs 88799 and 229324. While no amino acid sequence within the helper-component protease region differentiated the two groups of isolates, seed transmissibility was strongly associated with the presence of a DAG amino acid sequence motif in the coat protein coding region. The association between seed and aphid transmissibility suggests that the same regions of the SMV genome are involved in seed and aphid transmission.