September 13, 2005
From:  American Phytopathological Society, Plant Disease Notes [edited] <http://www.apsnet.org/pd/searchnotes/2005/PD-89-1012B.asp>


A survey of viruses affecting French bean (Phaseolus vulgaris) in Iran includes a 1st report of southern bean mosaic virus and bean pod mottle virus
N. Shahraeen and T. Ghotbi, Plant Pests and Diseases Research Institute (PPDRI) P.O. Box 19395-1454, Tehran, Iran; A. Dezaje Elkhache, East Azarbaejan Research Center, East Azarbaejan, Iran; and A. Sahandi, Plant Pests and Diseases Research Institute (PPDRI) P.O. Box 19395-1454, Tehran, Iran. Plant Dis. 89:1012, 2005; published on-line as DOI: 10.1094/PD-89-1012B. Accepted for publication 7 Jun 2005.

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 8 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, Braunschweig, 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 percent (35 samples) and 5 percent (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 6 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. Tendergreen). 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 1st 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.

References:
(1) W. J. Kaiser et al. Plant Dis. Rep. 52:687, 1968.
(2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.
(3) J. S. Semancik. Bean pod mottle virus. No. 108 in: Descriptions
of Plant Viruses. CMI/AAB, Kew, Surrey, England, 1972.
(4) J. H. Tremaine and R. I. Hamilton. Southern bean mosaic virus.
No. 274 in: Descriptions of Plant Viruses. CMI/AAB, Kew, Surrey,
England, 1983.

--
ProMED-mail
<promed@promedmail.org>

[BPMV was 1st reported in _Phaseolus vulgaris_ cv. Tendergreen; from Charleston, USA; by Zaumeyer and Thomas in 1948. It causes significant crop losses in soybean. It is spread primarily by the bean leaf beetle _Cerotoma trifurcata_ (bean leaf beetle), _Colaspis brunnea_ (grape colaspis), _Diabrotica balteata_, and southern corn root worm (_D. undecimpunctata_). BPMV is stable, easily transmitted mechanically and occurs at relatively high levels in seed coats from seeds of infected soybean. Yields from infected plants are lowered by
10-40 percent, grain quality is reduced both in oil and protein, seed germination is lower, and delayed maturation results in a condition known as "green stem." It can also be transmitted by mechanical inoculation, by grafting, but is not transmitted by seed or by pollen. BPMV spreads in the North American region.

The fact that BPMV has been reported in Iran is interesting, suggesting that infected seed may have been used for planting.

SBMV was 1st reported in _Phaseolus vulgaris_ from samples collected in Louisiana and California, USA by Zaumeyer and Harter in 1943. There are several strains (cowpea strain (strain C), Ghana strain (strain G), severe bean mosaic strain or Mexican strain (strain M) and the type strain (strain B). Symptoms persist in _P. vulgaris_,
_Vigna unguiculata_, _V. mungo_ and _Glycine max_. Symptoms include mosaic and/or mottle, and stunting (especially in _Vigna unguiculata_). SBMV is transmitted by beetles (_Ceratoma trifurcata_ and _Epilachna variestis_). It can also be transmitted by mechanical inoculation, by grafting, seed (3-7 percent in _V. unguiculata_ cv. Early Wilt Resistant Ramshorn), by pollen to the seed and transmitted by pollen to the pollinated plant. It has been reported from the African region, the North American region, the South and Central American region and France. SBMV probably entered Iran via infected seed; BPMV undoubtedly entered Iran in virus-infected seed.

The strategy for disease management involves managing the bean leaf beetle. Growers should consider a later planting of soybean, especially if BPMV was a yield limiting factor in 2004. Late planting can result in an increased risk of soybean aphid activity at a sensitive growth stage. Plant soybean varieties with the ability to yield in the presence of BPMV. Use good quality seed that is not mottled, and consider the field history of this problem before making decisions as to whether to spray for the bean leaf beetle. Sprays must be carefully timed to be effective.

Resistance to SBMV is not yet available, but partial resistance to BPMV exists in soybean varieties. Partial resistance is expressed as acceptable yield, low seed mottling and a low incidence of green stem in the presence of BPMV. Soybean varieties differ in yield and incidence of mottled soybean seed in the presence of BPMV. Early
soybean planting can coincide with high populations of over-wintered bean leaf beetle adults moving into soybeans to feed and lay eggs. This timing increases the chance of BPMV transmission to soybeans.

Links:
<http://extension.agron.iastate.edu/soybean/bpmv.html>
<http://www.lgseeds.com/LG_Tech2/soy_beanpodmottlevirus.asp>
<http://www.ipm.iastate.edu/ipm/icm/2000/4-24-2000/newsoyvir.html>
<http://pubs.caes.uga.edu/caespubs/pubcd/l114-w.html>
<http://www.plantpath.wisc.edu/soyhealth/pdf/bpmv_Giesleretal.pdf>
- Mod.DH]

[see also in the archive:
Bean common mosaic - Australia (WA): 1st report 20050202.0358 Bean yellow disorder virus - Spain: 2004 20050601.1527 Bean pod mottle virus, soybean - Iran (Golestan) 20050701.1852 2004
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Chickpea chlorotic dwarf virus - Syria 20040403.0912
Cowpea mild mottle virus, bean - Argentina: 1st report 20040921.2606 2002
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Bean pod mottle comovirus, soybean - Canada 20020501.4066 Chickpea chlorotic dwarf, sugarbeet & bean - Iran 20020509.4138 Broad bean wilt virus-1, pepper - Spain 20020707.4681 Faba bean necrotic yellows virus, pulses - Sudan 20021108.5752 2001
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Chickpea & lentil viruses, first reports - Iran 20010921.2295]