Factors affecting aphid acquisition and transmission of soybean mosaic virus

Abstract

SUMMARY Myzus persicae transmitted soybean mosaic virus (SMV) most efficiently following 30 or 60 s acquisition probes on infected plants. There were no differences in susceptibility to SMV infection of soybean plants 1 to 12 wk old, but symptoms were more severe in plants inoculated when young than when old. Soybeans inoculated between developmental stages R3 and R6 only showed yellowish‐brown blotching on one or more leaves. There were no observable differences in the time of appearance or type of symptoms shown by soybean seedlings inoculated either by sap or by aphids; infected plants became acquisition hosts for aphids 5–6 days after inoculation. There was no change in the efficiency with which M. persicae transmitted SMV from source plants up to 18 wk after inoculation. M. persicae transmitted SMV from leaves of field‐grown soybeans when plants were inoculated at developmental stages V6, R2, and R3 and tested as sources 57–74 days after inoculation but not from plants inoculated at R5 and tested as sources 14 to 32 days after inoculation. M. persicae acquired SMV from soybean buds, flowers, green bean pods, and unifoliolate, trifoliolate, and senescent leaves. Middle‐aged and deformed leaves were better sources of the virus than buds, unfolding and old symptomless leaves. The results are being incorporated into a computer model of SMV epidemiology.

Soybean leaf pubescence affects aphid vector transmission and field spread of soybean mosaic virus

“…One of the most important factors influencing the spread of SMV is aphid probing activity (Schultz et al, 1983). Our laboratory studies show that the incidence of SMV infection was negatively correlated with trichome density.…”

“…SMV strain G-5 (Cho & Goodman, 1979) was used throughout the study. This strain produces distinct symptoms without severely stunting the infected plant (Schultz et al, 1983).…”

“…Non-persistently transmitted viruses are rapidly acquired, often in less than a minute, during vector probing of virus-infected plants (D'Arcy & Nault, 1982). Soybean mosaic virus (SMV) is such a pathogen, being transmitted most efficiently by aphid vectors after 30-to 60-s acquisition probes (Schultz, Irwin & Goodman, 1983). However, efficiency to acquire and transmit SMV depends on the virus isolate, vector species, and cultivar of soybean, Glycine max (L.) Merr.…”

Prevalence, Incidence, and Spatial Dependence of Soybean mosaic virus in Iowa

“…Detection of SMV is best performed by directly testing for the presence of the virus rather than by assessing disease symptoms. Although most commercial soybean cultivars planted in Iowa are susceptible to SMV (9), soybean mosaic symptoms vary with soybean cultivar, virus strain, plant age at time of infection, and environment (6,9,14,15,28). Moreover, high temperatures that occur during the growing season in the Midwest can often mask SMV symptoms (10,15).…”