First report of the natural occurrence of eight viruses affecting soybeans in Iran

During the summer of 1999/2000, a survey of viruses infecting soybeans was conducted in five main soybean cultivation provinces of Iran (Golestan, Mazandaran, Ardebil, Lorestan and Khuzestan). A total of 3110 leaf samples were collected randomly from 80 soybean fields (30 to 50 samples per field). Samples were tested by the enzyme linked immunosorbent assay (ELISA) for the presence of 13 viruses by using antisera against Alfalfa mosaic virus (AlMV), Bean yellow mosaic virus (BYMV), Cucumber mosaic virus (CMV), Soybean mosaic virus (SMV), Tobacco mosaic virus (TMV), Tobacco ringspot virus (TRSV) and Tomato ringspot virus (ToRSV) [Sanofi, France]; Bean common mosaic virus (BCMV) [Adgen diagnostic, UK]; Tobacco streak virus (TSV) (As-0171, PV-0309) and Tomato spotted wilt virus (TSWV) (As-0526, As-0580, PV-0526) [DSMZ, Germany]; Pea enation mosaic virus-1 (PEMV-1) [Iranian pea isolate provided by Farzadfar]; Blackeye cowpea mosaic virus (BlCMV) [from Pinnow, USA]; and Peanut mottle virus (PeMoV) [Seed Pathology Institute, Denmark]. BlCMV and PeMoV were tested for by immuno-dot ELISA, and the other viruses by DAS-ELISA. Laboratory tests results indicated that the overall viral disease incidence was 15.7%. SMV was the most common virus, with an average of 13.3%, followed by TSWV (5.4%), TRSV (4.2%), TSV (4.1%), PEMV (2.9%), BYMV (2.2%), ToRSV (2.1%), TMV (1.5%), AlMV (1.3%), BCMV (0.8%) and CMV (0.6%). In addition, BlCMV was detected in selected symptomatic samples from Mazandaran and Lorestan, and PeMoV in samples from Golesta. Field symptoms associated with virus infection included: mosaic, mottling, crinkle, vein clearing and vein necrosis with SMV; mosaic and mottling with AlMV, BCMV, BlCMV, BYMV, PEMV, PeMoV and TMV; top necrosis in most TRSV and ToRSV infected plants; chlorosis and necrosis with TSWV. However, plants were frequently infected with more than one virus, so it was not possible to correlate specific symptoms with a particular virus. Although SMV, TSV, TRSV, ToRSV and TSWV have been previously recorded in soybean in Iran (Eskandari, 1978; Rahimian et al., 1995; Golnaraghi et al., 2001) and AlMV, BCMV, BYMV, CMV, PEMV-1 and PeMoV have been previously reported from other hosts (Kaiser et al., 1971; Shahraeen and Bananej, 1995), to the best of our knowledge, this is the first report of naturally occurring infections of AlMV, BCMV, BlCMV, BYMV, CMV, PEMV-1, PeMoV and TMV in soybean fields in Iran.