IDENTIFICATION AND PARTIAL CHARACTERIZATION OF AN ISOLATE OF APRICOT LATENT VIRUS FROM PALESTINE
N. Abou Ghanem-Sabanadzovic, H. Abbadi, M. Al Rwahnih, M.A. Castellano, A. Myrta
A filamentous virus was isolated by mechanical sap transmission from GF 305 seedlings showing asteroid ringspots to Nicotiana occidentalis. The GF 305 seedlings were graft-inoculated with buds from an apricot tree cv Mistikawi, from Palestine. The electrophoretic dsRNA pattern from symptomatic GF 305 and N. occidentalis showed a major band of about 9.5 kbp. Bundles of elongated virus-like particles were present in the cytoplasm of infected N. occidentalis. Dissociated coat protein from partially purified virus preparations consisted of a single subunit with an estimated Mr of ca. 50 kDa. RT-PCR using primers specific for Apricot latent virus (ApLV) RNA amplified a DNA product of about 200 bp from infected GF 305 and N. occidentalis plants. Sequence analysis of this fragment showed 90-93% identity in the encoded amino acid sequence with corresponding sequences from different ApLV isolates. This is the first record of ApLV from the southern Mediterranean. An ApLV-specific digoxygenin-labelled riboprobe was produced and used for molecular hybridisation tests. A survey of apricot orchards in Southern Italy did not show the presence of ApLV.