ABSTRACT
During May 2003, a high incidence of symptoms suggestive of virus infection in spring chickpea were observed in many fields in Al-Ghab Valley, Syria, the ICARDA farm (near Aleppo, Syria), as well as in other locations in northern Syria, including the Idleb governorate. Symptoms observed were yellowing, stunting, and necrosis. A total of 1,345 chickpea samples with these symptoms (331 from Al-Ghab Valley, 269 from the ICARDA farm, and 745 from the Idleb governorate) were collected and tested for the presence of five viruses with tissue-blot immunoassay (TBIA) (4) at the Virology Laboratory of ICARDA, using the following antisera: monoclonal antibodies for Faba bean necrotic yellows virus (FBNYV, genus Nanovirus) (1); Bean leafroll virus (BLRV, family Luteoviridae) (4B10) (3); Beet western yellows virus (BWYV, genus Polerovirus, family Luteoviridae [ATCC PVAS-647, American Type Culture Collection, Manassas, VA]); and Soybean dwarf virus (SbDV, family Luteoviridae, [ATCC PVAS-650]) and polyclonal antibodies for Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus, family Geminiviridae, provided by H. J. Vetten, BBA, Braunschweig, Germany). The most common virus present was BWYV (detected in 54.1% of samples tested), followed by CpCDV (19.2%), BLRV (10.2%), and FBNYV (5.5%). SbDV was not detected in any of the samples tested. Using immunosorbent electron microscopy, infected chickpea samples revealed low numbers of geminivirus-like particles after 15 min of incubation on CpCDV antiserum-coated grids. When CpCDV was purified from infected chickpea plants, the virus coat protein was 32 kDa with sodium dodecyl sulfate-polyacrylamide gel electrophoresis typical of CpCDV coat protein (2) and reacted strongly with CpCDV antiserum in western blots. The CpCDV vector in Syria was found to be Orosius albicinctus Distant, and is thought to be similar to Orosius orientalis (Matsumura), the reported vector of CpCDV (2). FBNYV, BWYV, and BLRV infection of chickpea have been previously reported from Syria, but to our knowledge, this is the first report of CpCDV infecting chickpea in Syria. References: (1) A. Franz et al. Ann. Appl. Biol. 128:255, 1996. (2) N. M. Horn et al. Ann. Appl. Biol. 122:467, 1993. (3) L. Katul. Characterization by serology and molecular biology of bean leaf roll virus and faba bean necrotic yellows virus. Ph.D. thesis. University of Gottingen, Germany, 1992. (4) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.
ABSTRACT
Symptoms suggestive of virus infection in barley, bread wheat, and durum wheat were observed at high incidence in November 2000 in Terbol, Beqa'a Valley, Lebanon. The symptoms were mainly stunting, accompanied by leaf striping and yellowing. Symptomatic plant samples (27 barley, 37 bread wheat, and 81 durum wheat) were collected and tested for the presence of four different viruses by tissue-blot immunoassay (TBIA) (1) at the Virology Laboratory of ICARDA, Aleppo, Syria. Antisera used were for Barley stripe mosaic virus (BSMV, genus Hordeivirus) (2); Barley yellow dwarf virus (BYDV, genus Luteovirus, family Luteoviridae) (PAV serotype) (2); Wheat streak mosaic virus (WSMV, genus Tritimovirus, family Potyviridae) (3); and Barley yellow striate mosaic virus (BYSMV, genus Cytorhabdovirus, family Rhabdoviridae) provided by M. Conti, Instituto di Fitovirologia applicata, Turino, Italy. BYSMV was detected in 12 barley, 18 bread wheat, and 56 durum wheat samples; the corresponding numbers of barley, bread wheat, and durum wheat plants testing positive for BYDV-PAV were 4, 7, and 6, respectively. BSMV and WSMV were not detected in any of the samples tested. BYSMV was purified from infected wheat plants, and the purified preparation had a UV 260:280 ratio of 1.18, typical of Rhabdoviruses. In SDS-polyacrylamide gel electrophoresis, the purified virus preparation indicated the presence of 66, 47, and 15 kDa structural proteins, typical of the G, N and M proteins of Rhabdoviruses. In western blot, the 66 and 47 kDa protein bands reacted strongly with BYSMV antiserum. This is the first record of BYSMV infecting barley and wheat in Lebanon. References: (1) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (2) K. M. Makkouk and S. G. Kumari. Rachis Newsl. 12:24, 1993. (3) K. M. Makkouk and S. G. Kumari. Rachis Newsl. 16:74, 1997.
