No abstract

Samples of mulberry leaves showing vein clearing, yellow speckle and leaf deformation symptoms were collected in the Fars Province of Iran. Grafting of buds from affected trees onto a number of healthy mulberry rootstocks resulted in transmission of the pathogen 40 days postinoculation. Likewise, mechanical inoculation of sap from affected leaves resulted in induction of similar symptoms in mulberry seedlings. Total nucleic acid was extracted from leaf tissues and subjected to reverse transcription polymerase chain reaction (RT-PCR) using Hop stunt viroid (HSVd) and Citrus exocortis viroid (CEVd)-specific primers, followed by sequencing of PCR products. RT-PCR with HSVd primers amplified a 302-or 305-bp product from affected samples, but none from healthy plants. CEVd was not detected in affected trees. HSVd was also found in graft-and mechanically inoculated plants. Sequence analyses showed three variants of HSVd in symptomatic mulberries related to plum and peach variants of this viroid with 94.9% identity, but with only 93% identity to Lebanese and Italian mulberry isolates. This is the first report of HSVd associated with vein clearing in mulberry in Iran.

No abstract

Background and Aims: CBLVd has been reported from northern of Iran previously. The aim of this study was evaluating new viroid variant from asymptomatic citrus trees of Fars province and comparing with its other isolates. Materials and Methods: In this study a number of citrus trees without symptoms were sampled and subjected to RNA extraction followed by RT-PCR, cloning and sequencing of PCR products. Molecular properties of viroid variants were compared. Results: A novel variant of CBLVd from Fars was achieved and used for comparison with a number of other CBLVd sequences from GenBank. It was shown that on the basis of sequence homology, CBLVd isolate from Fars province and two CBLVd isolates reported from Pakistan (Punjab) clustered in one group. It is supposed that these variants possibly will have same origin and probably imported from Pakistan to Iran by infected plant tissues or transplants. Conclusions: Therefore, we propose that the government regulates the importation of plants and plant products under the precise and rigorous authority of the plant protection institutes.