A Survey of Viruses Affecting French bean (Phaseolus vulgaris) in Iran Includes a First Report of Southern bean mosaic virus and Bean pod mottle virus.

Abstract

A survey was conducted from 2003 to 2004 to identify viruses infecting common bean (Phaseolus vulgaris L.) in different growing areas of East Azarbaejan Province of Iran. A total of 300 French bean samples with symptoms of viral infection (mosaic, vein clearing, leaf rolling, yellowing, and leaf distortion) were collected. The samples were tested for eight viruses using the tissue-blot immunoassay procedures (TBIA) (2) and double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) according to the manufacturer's instructions (DSMZ, Braun-schweig, Germany). ELISA tests for Alfalfa mosaic virus (AMV), Bean yellow mosaic virus (BYMV), Bean common mosaic virus (BCMV), Bean common mosaic necrosis virus (BCMNV), Cucumber mosaic virus (CMV), Bean leaf roll virus (BLRV), and Southern bean mosaic virus (SBMV) were used. In addition, antiserum was provided by S. A. Ghabrial (University of Kentucky, Lexington) to test for Bean pod mottle virus (BPMV). Serological tests showed that SBMV and BPMV were present in 12% (35 samples) and 5% (15 samples) of samples, respectively. BCMV, BCMNV, BYMV, BLRV, CMV, and AMV were more common and were detected in 155, 105, 80, 46, 30, and 10 samples of 300 samples, respectively. These six viruses were previously reported in other pulses and in French bean in Iran (1). The presence of SBMV and BPMV were verified in samples by transmission to French bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), and soybean (Glycine max) indicator test plants (3,4). Inoculation with extracts from SBMV-positive plants produced systemic mottle and mosaic symptoms in soybean (cv. Gorgan-3) and French bean (cvs. Dubbele Witte and Cheete). In cowpea (cv. Mashad) and French bean (cv. Pinto), inoculation produced necrotic local lesions. Inoculation with extracts from BPMV-positive plants produced severe mosaic, leaf distortion, and puckering in soybean (cv. Gorgan-3) and French bean (cv. Ten-dergreen). No symptoms were observed in cowpea (cv. Mashad). Cvs. Pinto and Bountiful bean reacted with necrotic local lesions. All indicator test plants tested positive for the presence of SBMV or BPMV as expected using DAS-ELISA. To our knowledge, this is the first report of BPMV and SBMV naturally infecting French bean in Iran. These viruses can cause a serious problem to other leguminous crops grown in Iran.