First report of pittosporum cryptic virus-1 in Lebanon

Pittosporum tobira or Japanese pittosporum is an ornamental greenhouse plant used widely in landscaping and along roadsides as well as in parks and gardens. In Lebanon, symptoms of chlorotic vein banding were observed on six plants of P. tobira growing in different 2 gardens located in Beqaa Valley in. A total of 35 samples were collected from symptomatic and symptomless plants and were tested by Elisa for the presence of eggplant mottled dwarf virus and Tomato spotted wilt virus. None of these viruses was detected in the collected samples. Total RNA was extracted from the 6 symptomatic plants and other 6 asymptomatic ones and tested by reverse transcription (RT)-PCR assay for the presence of Pittosporum cryptic virus 1 (PiCV1) using a pair of PiCV1-specific primers: PiCV1-F: (5'TGGCAGCATTACCGAAGGTT3') and PiCV1-R: (5'TGTGTCGGCAATCAAAGGGA3') which was designed on the available sequence in GenBank (Accession No. LN680393) and targeting 279bp in the RdRp gene. As expected, the 6 symptomatic plants reacted positively and showed the amplified specific bands. For further confirmation, PCR products from 3 infected plants were cloned and sequenced. BLAST analyses revealed 99% nucleotide identity with the Italian isolate Pit-MAIB, and 99-100% similarity among the Lebanese isolates. Based on this information, the isolates were positively identified. To the best of our knowledge, this is the first report of PiCV1 causing chlorotic vein banding on P. tobira in Lebanon. P. tobira infection with PiCV1 was firstly reported in Italy. Even there are no known natural vectors for Partitiviruses that infect plants and they cannot be mechanically inoculated, Partitiviruses can be transmitted with high efficiency intracellularly via plant seeds, or infected cuttings and this might have evidence consequences of PiCV1 in other Lebanese governorates as well as neighboring countries.