Abstract
Two surveys were performed in the important alfalfa-producing regions in Saudi Arabia during (2012-2014) for detection of viruses suspected of inciting wide spread symptoms in alfalfa using DAS-ELISA and RT-PCR. Red clover vein mosaic virus (RCVMV) was among the viruses detected in the five visited regions. It contributed to average infection rates of 1.4% in the first survey (2012-2013) and 18.2% in the second survey (2014). Representative samples from the surveyed regions that tested positive by ELISA, also tested positive by RT-PCR confirming occurrence of this virus. RCVMV was also detected in Solanum tuberosum, Vicia faba, Sonchus oleraceous and Chenopodium spp. growing adjacent to alfalfa fields for the first time in Saudi Arabia. Sequencing of purified RT-PCR products indicated a close phylogenetic relationship among the Saudi isolates of RCVMV (99-100%) and a distant relationship with isolates deposited in the GenBank. Five of the plant species tested in the host range study were found positive to RCVMV infection and produced mild symptoms. To our knowledge this is the first report of cowpea [Vigna unguiculata (L.) Walp.] and black-eyed pea [V. unguiculata subspecies unguiculata (L) Wahl] as hosts for RCVMV and can be used for its propagation (C) 2018 Friends Science Publishers.