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

Abstract

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 (30–50 samples per field). Samples were tested by the enzyme-linked immunosorbent assay (ELISA) for the presence of 13 viruses 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 Pytho-Diagnostics, 92430 Marnes-la-Coquette, France); Bean common mosaic virus (BCMV) (Adgen Ltd, Auchincruive, KA6 5HW, UK); Tobacco streak virus (TSV) (As-0171, PV-0309) and Tomato spotted wilt virus (TSWV) (As-0526, As-0580, PV-0526) (DSMZ, BBA Messeweg 11/12, D-38104 Braunschweig, Germany); Pea enation mosaic virus-1 (PEMV-1) (Iranian pea isolate provided by S. Farzadfar); Blackeye cowpea mosaic virus (BlCMV) (from Dr Pinnow, Department of Plant Pathology and Physiology, Clemson University, SC 29631, USA); and Peanut mottle virus (PeMoV) (Seed Pathology Institute, Flakkejerg, DK-4200 Slagelse, Denmark). The latter two viruses were tested for by immunodot ELISA, and the other viruses by double antibody sandwich-ELISA. Laboratory tests results indicated that the overall virus 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 samples with symptoms 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; and chlorosis and necrosis with TSWV. Plants were frequently infected with more than one virus, however, so it was not possible to correlate specific symptoms with a particular virus. SMV, TSV, TRSV, ToRSV and TSWV have previously been 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 previously been reported from other hosts (Kaiser et al ., 1971; Shahraeen & Bananej, 1995). However, 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.