First Report of Barley yellow striate mosaic virus Infecting Barley and Wheat in Lebanon.

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.