الملخص الإنجليزي
BlastN comparison showed PT-2 and PT-3 from petunia were 94 to 95% identical to the sequences of ChCLV from Oman (JN604490 to JN604500), which were obtained from other hosts. ClustalV multiple sequence alignment showed that isolates PT-2 and PT-3 shared maximum sequence identity of 93.3 and 92.8%, respectively, with an isolate of ChLCV-OM (JN604495). According to ICTV rules for begomoviruses, PT-3 should be considered to be a new strain of ChLCV-OM and PT-2 a variant of the already existing ChLCV-OM strain. We propose the name for this new strain as the "Petunia strain" of Chili leaf curl virus (ChLCV-Pet). Two infectious clones were constructed from the PT-2 and PT-3 sequences, clones as 1.75-genome sequences in a binary vector, suitable for agroinfection to confirm their infectivity. Both clones, PT-2 and PT-3, produced typical leaf curl disease symptoms upon inoculation on petunia 18 days post inoculation. The presence of the same virus in symptomatic field infected and inoculated petunia was confirmed by Southern blot using 650 bp DIG labeled probe prepared from CP region of PT-3 isolate. ChLCV-OM, a monopartite begomovirus, is widely associated with leaf curl disease of tomato and pepper in Oman, with its origin traced to the Indian subcontinent (2). Identification of a new strain of ChLCV from petunia provides evidence of an ongoing rapid evolution of begomoviruses in this region. Although petunia has been tested as an experimental host for some begomoviruses (1,4), this is the first report of petunia as natural host for ChLCV, a begomovirus previously reported in tomato and pepper in Oman.
