Incidence of Viruses Infecting Alfalfa in the Southeast and Central Regions of Iran

Alfalfa crops were surveyed for the incidence of alfalfa mosaic virus (AMV), cucumber mosaic virus (CMV), peanut stunt virus (PSV), bean leaf roll virus (BLRV), bean yellow mosaic virus (BYMV) and bean common mosaic virus (BCMV) in the major growing areas in the southeast and central regions of Iran. Samples were collected between May 2009 and March 2011 and analyzed for viral infection initially by enzyme-linked immunosorbent assay (ELISA) followed by RT-PCR using capsid protein gene specific primers. In total, 634 symptomatic leaf samples were collected in four southeastern and central provinces of Iran representing 20 regions. Our results revealed a high incidence of AMV over a wide geographical area. AMV and BLRV were identified in most regions, whereas BYMV was found only in Yazd Province. PSV was detected in three regions, but not in Sistan- Balouchestan and Hormozgan Provinces. The highest incidence of viral infection amongst the surveyed provinces was recorded in Kerman (66.8%), followed by Yazd (39%), Sistan and Balouchestan (20.8 %), and Hormozgan (4.5%). AMV, BLRV, PSV and BYMV were present in 23.3%, 12%, 0.70 % and 0.28 % of the samples, respectively. CMV and BCMV were not detected in any surveyed region. Multiple virus infections were recorded in 42 samples. This is the first report on the detected occurrence of BLRV, PSV and BYMV in alfalfa in the southeast and central regions of Iran