Virology Laboratory, Germplasm Program, ICARDA, P.O. Box 5466, Aleppo, Syria
Federal Biological Research Centre for Agriculture and Forestry, Institute for Plant Virology, Microbiology and Biosafety, Messeweg 11--12, D-38104 Braunschweig, Germany
Virus-like symptoms not commonly encountered on most chickpea (Cicer arietinum L.) and grasspea (Lathyrus sativus L.) genotypes were noticed at the ICARDA farm near Aleppo, Syria, during April and May 2001. Primary symptoms included stunting, accompanied by leaf mottling and yellowing. The causal agent was transmitted by the pea aphid (Acyrthosiphon pisum Harris) in a persistent manner. Efficiency of transmission was 100% when aphids acquired the virus from grasspea and then inoculated lentil, whereas transmission efficiency was 21% when aphids acquired the virus from chickpea and then inoculated lentil. Samples of symptomatic chickpea and grasspea reacted strongly with the antiserum prepared against a Dutch isolate (E154) of Pea enation mosaic virus (PEMV), provided by L. Bos (Wageningen, the Netherlands) (1), using tissue blot immunoassay (2). Negatively stained preparations from chickpea and grasspea revealed typical PEMV-like isometric particles ≈30 nm in diameter. With immunoelectron microscopy, these particles were effectively trapped and strongly decorated with PEMV antibodies (immunoglobulin G diluted 1:10) provided by M. Musil (Bratislava, formerly Czechoslovakia) (4). The virus capsid protein was 22 kDa based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, typical of the PEMV coat protein, and reacted strongly with PEMV antiserum (E154) in western blots. This is the first report of PEMV naturally infecting chickpea and grasspea in Syria and, to our knowledge, the first report in West Asia. PEMV reached epidemic levels on lentil in Syria for the first time in 1994 (3). Field symptoms observed in May 2001 suggest that PEMV may also seriously affect lentil, chickpea, and grasspea crops in Syria.
References: (1) K. Mahmood and D. Peters. Neth. J. Plant Pathol. 79:138, 1973. (2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (3) K. M. Makkouk et al. Plant Dis. 83:303, 1999. (4) M. Musil et al. Acta Virol. 14:285, 1970.